NW Climate Science Digest
Aquatic Resources, Stream Flow, Hydrology in the Western U.S.
Post-fire disturbance impacts on snow hydrology in the Oregon Cascades
Gleason, K.E., Nolin, A.W. 2016. Charred Forests Accelerate Snow Albedo Decay: Parameterizing the Post-Fire Radiative Forcing on Snow for Three Years Following Fire. Hydrologic Processes. 3(11). DOI: 10.1002/hyp.10897.
Hydrologic models of snow-dominated watersheds that have experienced severe forest fires require an understanding of the post-fire disturbance impacts on snow hydrology. Oregon State University scientists Kelly Gleason and Anne Nolin studied the impact of post-fire disturbance on the radiative forcing of snow hydrology in the Oregon Cascades. The authors studied the radiative forcing impacts on in a charred forest of the Oregon Cascades that experienced severe forest fires in 2011. They measured snow albedo (reflectivity), monitored snow and micrometeorological conditions, sampled snow surface debris, and modeled snowpack energy and mass balance in adjacent burned and unburned forest sites. These field measurements showed that charred forests accelerate radiative forcing and advance snow disappearance for several years following fire.
Improved bias correction techniques for hydrologic simulations of climate change
Pierce, D. W., Cayan, D. R., Maurer, E. P., Abatzoglou, J. T., & Hegewisch, K. C. (2015). Improved bias correction techniques for hydrological simulations of climate change. Journal of Hydrometeorology, (2015).
Global climate model output typically needs to be bias corrected before it can be used for climate change impact studies. Researchers from Scripps, USGS, Santa Clara and University of Idaho applied three existing bias correction methods, and one new one they developed, to daily maximum temperature and precipitation from 21 global climate models (GCMs) to investigate how different methods alter the climate change signal of the GCM. The quantile mapping (QM) and cumulative distribution function transform (CDF-t) bias correction methods significantly altered the GCM’s mean climate change signal, with differences of up to 2°C and 30 percentage points for monthly mean temperature and precipitation, respectively. Equidistant quantile matching (EDCDFm) bias correction preserved GCM changes in mean daily maximum temperature, but not precipitation. An extension to EDCDFm termed PresRat was introduced, which generally preserved the GCM changes in mean precipitation. Another problem is that GCMs can have difficulty simulating variance as a function of frequency. To address this, a frequency-dependent bias correction method was introduced that is twice as effective as standard bias correction in reducing errors in the models’ simulation of variance as a function of frequency, and does so without making any locations worse, unlike standard bias correction. Lastly, a preconditioning technique was introduced that improved the simulation of the annual cycle while still allowing the bias correction to take account of an entire season’s values at once.
Simplifying hydrologic modeling
Markstrom, S.L., Hay, L.E., Clark, M.P. 2016. Towards simplification of hydrologic modeling: identification of dominant processes. Hydrol. Earth Syst. Sci. 20, 4655-4671. doi:10.5194/hess-20-4655-2016
Hydrologic scientists from the United States Geologic Survey underwent a parameter sensitivity analysis of the Precipitation-Runoff Modeling System’s simulation of the conterminous United States. The authors used the parameter sensitivity analysis to identify both the sensitive input parameters and the output variables that were potentially associated with dominant hydrologic processes. The study calibrated sensitivity values of over 100,000 independent units and associated them with hydrologic processes such as snowmelt, surface runoff., infiltration, soil moisture, evapotranspiration, interflow, baseflow, and runoff, as well as model performance statistics such as mean, coefficient of variation and autoregressive lag 1. The authors then used the identified parameters and processes to understand model performance at the location of each unit. Among the findings from this study, the authors highlight that specific performance statistics and output variables have strong influences on parameter sensitivity, and that model complexity can be reduced by focusing on hydrologic processes that are associated with sensitive parameters.
Snow science supporting our nation's water supply
A NASA-led research campaign called SnowEx was recently launched in Colorado. The amount of water in snow plays a critical role in water availability for drinking water, agriculture, and energy, however an accurate measurement of how much water is stored in snow has remained a major obstacle for scientists. The goal of SnowEx is to create and refine the best snow-measuring techniques in order to build an accurate map of water content contained in the nation’s snow. Data collected from SnowEx will be available to the public and stored at the National Snow and Ice Data Center in Boulder, Colorado. Learn more about SnowEx.
Estimates of twenty-first-century flood risk in the Pacific Northwest based on regional climate model simulations
Eric P. Salathé Jr., Alan F. Hamlet, Clifford F. Mass, Se-Yeun Lee, Matt Stumbaugh, and Richard Steed, 2014: Estimates of Twenty-First-Century Flood Risk in the Pacific Northwest Based on Regional Climate Model Simulations. J. Hydrometeor, 15, 1881–1899. doi: http://dx.doi.org/10.1175/JHM-D-13-0137.1http://cses.washington.edu/db/pubs/abstract810.shtml
Results from a regional climate model simulation show substantial increases in future flood risk (2040–69) in many Pacific Northwest river basins in the early fall. Two primary causes are identified: 1) more extreme and earlier storms and 2) warming temperatures that shift precipitation from snow to rain dominance over regional terrain. The simulations also show a wide range of uncertainty among different basins stemming from localized storm characteristics. While previous research using statistical downscaling suggests that many areas in the Pacific Northwest are likely to experience substantial increases in flooding in response to global climate change, these initial estimates do not adequately represent the effects of changes in heavy precipitation. Unlike statistical downscaling techniques applied to global climate model scenarios, the regional model provides an explicit, physically-based simulation of the seasonality, size, location, and intensity of historical and future extreme storms, including atmospheric rivers.
Coastal Cutthroat Trout Ecohydrology and Habitat use in Irely Creek, Washington
Coastal cutthroat trout are native in the Irely Creek watershed of the upper Quinault River drainage, which is protected as Olympic National Park. This species coexists with anadromous coho salmon, two resident fishes, and several amphibian species. During 2001-2002, cutthroat redds and fry were abundant in the main stem, such that researchers had adequate data to formulate microhabitat suitability curves for spawners and assess the incubation period before fry emergence. The results were similar to spawning resident trout species. Those results suggest that cutthroat trout require lower stream flows than salmon or steelhead for reproduction.
Tracking Interannual Streamflow Variability with Drought Indices in the U.S. Pacific Northwest
John T. Abatzoglou, Renaud Barbero, Jacob W. Wolf, Zachary A. Holden. (2014) Tracking Interannual Streamflow Variability with Drought Indices in the U.S. Pacific Northwest. Journal of Hydrometeorology 15:5, 1900-1912. Online publication date: 1-Oct-2014.
Sensitivity of gross primary production in the Rocky Mountains to summer rain
Berkelhammer, M., Stefanescu, I., Joiner, J. and Anderson, L. In press. High sensitivity of gross primary production in the Rocky Mountains to summer rain. Geophysical Research Letters, 44. DOI: 10.1002/2016GL072495
Researchers from the University of Illinois, the National Aeronautcics and Space Administration and the U.S. Geological Survey collaborated to investigate how decreasing peak snowpack in the Rocky Mountains will influence terrestrial gross primary production (GPP). They used a proxy for GPP collected from satellite data to compare precipitation data across the intermountain west and found that annual precipitation patterns explained most of the spatial and temporal variability in terrestrial GPP. They also found that terrestrial GPP was approximately twice as sensitive to variations in summer rain than snow pack. The study suggests the rain use efficiency of Rocky Mountain ecosystems is strongly dependent on both precipitation form and timing.
Effects of bark beetle-induced tree mortality on streamflow
Biederman J.A., Somor A.J., Harpold A.A., Gutmann E.D., Breshears D.D., Troch P.A., Gochis D.J., Scott R.L., Meddens A.J.H., Brooks P.D. 2015. Recent tree die-off has little effect on streamflow in contrast to expected increases from historical studies. Water Resources Research 51, doi: 10.1002/2015WR017401
Extensive research has been conducted on the impacts of bark beetles on trees in the Western US. Bark beetle epidemics have led to widespread tree mortality in many areas. Although this was expected to result in increased streamflow, observations have not shown this to be the case. In this study, the authors explored the response of streamflow in eight catchments that had been affected by bark beetles and experienced large tree die-offs. They compared streamflow in affected catchments with control catchments for the decade following the die-offs and conducted a separate trend analysis using climate-driven linear models. They found no change in streamflow in the majority of catchments, excluding one catchment that showed a consistent decreasing signal in streamflow. Although this was a somewhat surprising result, it is likely a result of increases in transpiration as well as differences in snow interception due to a decrease of forest canopy. In the absence of a thick forest canopy, snow can sublimate more easily and evaporation can occur more readily, which likely reduced streamflow, resulting in little to no changes in streamflow before and after the tree die-offs.
A New Publicly Available Database of Watershed Metrics for the United States
Hill, Ryan A., Marc H. Weber, Scott G. Leibowitz, Anthony R. Olsen, and Darren J. Thornbrugh, 2016.The Stream-Catchment (StreamCat) Dataset: A Database of Watershed Metrics for the Conterminous United States. Journal of the American Water Resources Association (JAWRA) 52(1): 120-128. DOI:10.1111/1752-1688.12372
A new dataset containing landscape metrics for upstream watersheds and catchments in the conterminous United States has been developed by the Environmental Protection Agency’s Office of Research and Development. Called the Stream-Catchment (StreamCat) Dataset, this tool allows the distribution of catchments and watersheds to be visualized for the conterminous United States. The database has been made available to the public which allows researchers and managers to access landscape information without the need for specialized geospatial expertise. The extensive resource will be useful for better understanding and characterizing river systems in the United States. This article, published in the Journal of the American Water Resources Association, detailed the development and main features of the dataset, including specific landscape features used; scripts and algorithms built to produce watershed summaries; and quality assurance procedures for ensuring data consistency.
Estimates of twenty-first-century flood risk in the Pacific Northwest based on regional climate model simulations
Eric P. Salathé Jr., Alan F. Hamlet, Clifford F. Mass, Se-Yeun Lee, Matt Stumbaugh, and Richard Steed, 2014: Estimates of Twenty-First-Century Flood Risk in the Pacific Northwest Based on Regional Climate Model Simulations. J. Hydrometeor, 15, 1881–1899. doi: http://dx.doi.org/10.1175/JHM-D-13-0137.1
Results from a regional climate model simulation show substantial increases in future flood risk (2040–69) in many Pacific Northwest river basins in the early fall. Two primary causes are identified: 1) more extreme and earlier storms and 2) warming temperatures that shift precipitation from snow to rain dominance over regional terrain. The simulations also show a wide range of uncertainty among different basins stemming from localized storm characteristics.
Plants’ future water use affects long-term drought estimates
Swann, A., Hoffman, F.M., Koven, C.D., Randerson, J.T. 2016. Plant responses to increasing CO2 reduce estimates of climate impacts on drought severity. Proceedings of the National Academy of Sciences (113): 36, 10019-10024. Doi: 10.1073/pnas.1604581113
University of Washington scientist, Abigail Swann, and colleagues incorporated a new layer of complexity to the study of plant response to climate change in this recently published study. The authors used Earth Systems Models that incorporated plant-centric features, such as P-E (precipitation minus evapotranspiration) and soil moisture, in order to capture a more accurate projection of plant response to increased atmospheric CO2. The study found that the plant-centric projections included changes to plant water use that increased plant resilience during warmer periods. This was in contrast to results from atmosphere-centric simulations that project severe increases in drought-stress on plants. Such models saw increases in 70% of global land area while the plant-centric models projected increases in 37% of global land area. The authors concluded that in order to reduce uncertainties in future projections, models much incorporate drought metrics that account for the response of plant transpiration to changing CO2.
Impacts of climate change on groundwater resources in Washington state
Pitz, Charles. 2016. Predicted Impacts of Climate Change on Groundwater Resources of Washington State. Washington State Department of Ecology. Publication No. 16-03-006
The Washington State Department of Ecology recently released a synthesis report on the climate-induced impacts of groundwater resources in the state. Author and hydrogeologist Charles Pitz evaluated and recommended preferred methods for assessing climate change impacts on groundwater storage. The author then described the current understanding of climate change impacts on five different groundwater characteristics: groundwater recharge/storage, surface water interactions/baseflow discharge, quality, temperature, and the impacts of sea-level rise. The report concludes with recommendations for Washington State water resource managers on improving protections against groundwater storage loss through increased and better statewide monitoring and assessing.
Trends and sensitivities of low streamflow extremes to discharge timing and magnitude in Pacific Northwest mountain streams
Kormos, P. R., Luce, C. H., Wenger, S. J., & Berghuijs, W. R. (2016). Trends and sensitivities of low streamflow extremes to discharge timing and magnitude in Pacific Northwest mountain streams. Water Resources Research Water Resour. Res. doi:10.1002/2015wr018125
Scientists from the U.S. Forest Service developed a method for examining the various forces affecting the magnitude of low streamflow extremes in the Pacific Northwest. Historical data shows that low streamflow extremes are dominantly controlled by amount of precipitation rather than air temperatures that change the timing of snowmelt. However, changes in precipitation due to climate change are not well understood. In this recently published study, Kormos et. al used mean streamflow as a proxy for precipitation and streamflow timing as a proxy for air temperature in order to quantify their relative influences on low streamflow extremes for 42 stream gauges. These methods showed that winter low flow metrics are weakly tied to both mean annual streamflow (precipitation forces) and center of timing (air temperature forces).
Columbia River Basin Impacts Assessment – Quarterly Update
The Columbia River Basin Impacts Assessment is an activity of the West Wide Climate Risk Assessments (WWCRA), which is part of the Bureau of Reclamation’s (Reclamation) WaterSMART Basin Study Program (WaterSMART Program) established under the SECURE Water Act (2009). More information on the background of this legislation can be found in the first Quarterly Update. Since the last Quarterly Update, Reclamation has been creating future climate change flows at specific locations throughout the Columbia River Basin. In addition, staff have been preparing the upper Snake River reservoir model to conduct operational modeling on the Snake River above Brownlee Reservoir.
Wetlands in a Changing World: Wading into Science for American Wetlands Month
Wetlands across the U.S. and around the world act as a crucial link between land and water, providing a number of services such as removing excess nutrients, pollutants, and sediment from water and acting as natural buffers to floodwaters. In 1991, the Environmental Protection Agency established May as American Wetlands Month to celebrate the importance of these ecosystems. Understanding both the impact of climate change on wetlands and the role that wetlands play in adapting to climate change is a vital part of ensuring climate change preparedness. Luckily, scientists across the country are already examining these relationships. To support this scientific endeavor, several of the eight regional Department of the Interior Climate Science Centers (CSCs) have funded research projects that focus on ways to improve the methods and tools used in wetland research and to help shed light on how changes in climate might affect these invaluable resources. The results of these studies are often used to support planning and decision-making by natural and cultural resource managers. Keep reading to learn more about this work and to get a glimpse of some of the findings that describe what our future may hold for wetlands and their inhabitants.
Stream Temperature Patterns over 35 Years in a Managed Forest of Western Washington:
Reiter & colleagues. 2015. Stream temperature patterns over 35 years in a managed forest of western Washington. Journal of the American Water Resources Association DOI:10.1111/1752-1688.12324
Water temperature in the upper Deschutes River watershed, Washington has been monitored since 1975 and represents one of the longest studies of water quality on managed forests in the Pacific Northwest. The authors used this data to examine the combined effects of hydro-climatic patterns and forest management on stream temperature. They found that the effects of harvest conducted prior to buffer regulations were obvious and most pronounced on smaller streams. They did not detect any response on larger channels to more recent timber harvest where riparian buffers were required. In many cases the temperature improvements associated with more stringent buffer requirements implemented over the last 35 years in the Deschutes watershed have been offset by warming climatic conditions. This emphasizes that it is critical to account for changing climate when examining long-term temperature patterns.
Projecting precipitation throughout the 21st century over North America
Wang, J. and V.R. Kotamarthi 2015. High-resolution dynamically downscaled projections of precipitation in the mid and late 21st century over North America. Earth’s Future, 3, doi:10.1002/2015EF000304.
In this new study, high spatial resolution (12 km) simulations were performed using the Weather Research and Forecasting (WRF) model. The purpose of the simulations was to explore mean and extreme precipitation projections for the mid to late 21st century. Because of the higher spatial resolution of the simulations, the study allowed for resolving precipitation in ways that had not previously been possible (such as over mountain ranges). The authors found that among 10 subregions they studied, the Pacific Northwest showed the greatest increase in the number of days each year when extreme precipitation occurs. This was the case for both emissions scenarios studied, RCP 4.5 and RCP 8.5, but there was a higher increase in the number of days with extreme precipitation for RCP 8.5.
Selecting climate change scenarios for specific impacts
Vano JA, Kim JB, Rupp DE, Mote, PW (2015). Selecting climate change scenarios using impact-relevant sensitivities. Geophys Res. Lett 42(13), 5516-5525. Doi: 10.1002/2015GL063208
Climate change studies oftentimes involve the selection of a small number of climate scenarios, with varied methods for how to select which climate models and scenarios should be chosen. Vano et al. develop a method that characterizes climate projections on an impacts spectrum that uses a sensitivity analysis technique described in Vano and Lettenmaier (2014). Performance of the climate models is specific to the Pacific Northwest region. Rather than selecting climate models based on which models best approximate climate in the Pacific Northwest, this method shows how climate models (and scenarios) are chosen for particular impacts. This is a “bottom-up meets top-down” approach that makes the climate impact in question of primary importance in the climate model and scenario selection process. Once the climate models and scenarios are selected, simple sensitivity analysis was used to understand how a particular variable responds to incremental temperature and precipitation changes. Examples highlighted in the study include changes in streamflow and annual vegetation carbon in the Pacific Northwest.
Washington Stream Thermal-Scape is Complete
The NorWeST webpage hosts stream temperature data and geospatial map outputs from a regional temperature model for the Northwest U.S. The temperature database was compiled from hundreds of biologists and hydrologists working for dozens of resource agencies and contains more than 45,000,000 hourly temperature recordings at more than 15,000 unique stream sites. The NorWeST project is funded by the Great Northern and North Pacific Landscape Conservation Cooperatives and the project goals are to develop a comprehensive regional database and high-resolution stream climate scenarios to facilitate climate vulnerability assessments, interagency coordination of temperature monitoring, & research on thermal ecology.
Effects of climate change on montane wetlands
Lee S-Y, Ryan ME, Hamlet AF, Palen WJ, Lawler JJ, Halabisky M (2015) Projecting the hydrologic impacts of climate change on montane wetlands. PLOS One 10(9): e0136385. doi: 10.1371/journal.pone.0136385
A new study published by UW researchers, among others, examines the effects of drought on wetlands in the mountains of the Pacific Northwest. Montane wetlands are thought to be one of the most sensitive ecosystems to changes in climate, because their existence depends on direct effects of climate, including precipitation, snowpack and evaporation. The authors develop a new method for projecting climate impacts on wetlands located in the mountains. They use a combination of observations of water levels in the wetlands and simulated soil moisture to relate soil moisture to wetland water levels to understand four types of wetlands (ephemeral, intermediate, perennial and permanent) in the Pacific Northwest. They use reconstructed historical data to project climate impacts on the wetlands for the 2040s and 2080s (A1B emissions scenario). They find that climate change will have strong effects on montane wetlands. Water levels will decrease, transient wetlands will exist for shorter periods, and some wetlands will dry up entirely. Wetlands classified as ‘intermediate hydroperiod wetlands’ will experience the most dramatic effects as they shift to transient wetlands. A significant issue with these results, as described by a UW press release (see link below), includes a loss of habitat for pond species. Montane wetlands are a key habitat for Cascades frogs, toads, newts and salamanders. They’re also a crucial water source for shrews, mountain lions and other species. Higher up on the food chain, ponds are important source of food for birds, snakes and mammals. The most vulnerable ponds, the intermediate hydroperiod wetlands, are the most significant habitat for frogs and salamanders, and the Cascades frog is already listed under the Endangered Species Act. The frog species is a very unique species of frog that only exists at high elevations in Washington, Oregon and California. The species has a lifespan of greater than 20 years and can survive under tens of feet of snow.
Global volume and distribution of groundwater and its vulnerability to climate change
Gleeson, T., Befus, K. M., Jasechko, S., Luijendijk, E., & Cardenas, M. B. (2015). The global volume and distribution of modern groundwater. Nature Geoscience.
In this new study, scientists updated a 40-year-old estimate of the Earth’s total volume of groundwater. The study compiled geochemical, geologic, hydrologic, and geospatial datasets with numerical simulations of groundwater, as well as analyzed modern groundwater (less than 50 years old) from tritium measurements. Modern groundwater is important because it is; 1) a better renewable resource than older groundwater, 2) a huge component of the hydrologic cycle as well as global biogeochemical cycles, and 3) more vulnerable to industrial or agricultural contamination. This study distinguishes modern groundwater from older groundwater by measuring tritium, an isotope of hydrogen whose concentration in precipitation peaked approximately 50 years ago (during above-ground thermonuclear testing). The study found that less than 6% (0.1-5.0 million km3) of the groundwater in the uppermost portion of Earth’s landmass is modern. Despite seeming minor, the volume of modern groundwater is equivalent to a body of water with a depth of about 3 m spread evenly over the continents. This water resource dwarfs all other components of the active hydrologic cycle and will be critical for future energy, food security, human health, and ecosystems.
Study Demonstrates Shift from Snow to Rain Leads to Decrease in Streamflow
In a warming climate, precipitation is less likely to occur as snowfall. A shift from a snow- towards a rain-dominated regime is currently assumed not to influence the mean streamflow significantly. The study argues however that mean streamflow is likely to be reduced for catchments that experience significant reductions in the fraction of precipitation falling as snow. With more than one-sixth of the Earth's population depending on meltwater for their water supply, and ecosystems that can be sensitive to streamflow alterations, the socio-economic consequences of a reduction in streamflow can be substantial. The study demonstrates that a higher fraction of precipitation falling as snow is associated with higher mean streamflow, compared to catchments with marginal or no snowfall.
Future projections of streamflow magnitude and timing differ across coastal watersheds of the western U.S.
Burke, W. D. and Ficklin, D. L. (2017), Future projections of streamflow magnitude and timing differ across coastal watersheds of the western United States. Int. J. Climatol. doi:10.1002/joc.5099
While streamflow timing of western U.S. watersheds has shifted earlier in mountainous snow-dominated watersheds due to earlier snowmelt, timing for rain-dominated coastal watersheds has shifted to later in the year. Despite these dissimilarities, coastal watersheds have received little attention in the literature. This research assessed changes in projected climate and hydrology for five small coastal basins in Washington, Oregon, and California. Projections of temperature and precipitation were coupled with the Soil and Water Assessment Tool hydrologic model to simulate future hydrology for each watershed. The response of climate, streamflow discharge, and timing was analyzed for each watershed by comparing the projected mid-21st century and late-21st century to the historical period. While temperature is projected to increase at each watershed from 1 to 6°C by the end of the 21st century, precipitation varies widely with the median and mean change across all watersheds and GCMs being close to zero. Changes in the magnitude of peak winter streamflow discharge differ across the region compared to the historical period. The projected decreases in peak winter streamflow magnitude have critical implications for water supply, which is already strained from extensive drought and high demand.
Special issue of Northwest Science devoted to climate change impacts on the Skagit River Basin
Rybczyk, JM, Hamlet AF, MacIlroy C, Wasserman L (2016) Introduction to the Skagit Issue - From Glaciers to Estuary: Assessing Climate Change Impacts on the Skagit River Basin. Northwest Science 90(1): 1-4. Doi: 10.3955/046.090.0102
Riedel JL and Larrabee MA (2016). Impact of recent glacial recession on summer streamflow in the Skagit River. Northwest Science 90(1): 5-22. Doi: 10.3955/046.090.0103
Lee S-Y, Hamlet AF, Grossman EE (2016) Impacts of climate change on regulated streamflow, hydrologic extremes, hydropower production, and sediment discharge in the Skagit River Basin. Northwest Science 90(1): 23-43. Doi: 10.3955/046.090.0104
Stumbaugh M and Hamlet AF (2016) Effects of climate change on extreme low-flows in small lowland tributaries in the Skagit River Basin. Northwest Science 90(1): 44-56. Doi: 10.3955/046.090.0105
Hamman JJ, Hamlet AF, Lee S-Y, Fuller R, Grossman EE (2016) Combined effects of projected sea level rise, storm surge and peak river flows on water levels in the Skagit floodplain. Northwest Science 90(1): 57-78. Doi: 10.3955/046.090.0106
Hood WG, Grossman EE, Veldhuisen C (2016) Assessing tidal marsh vulnerability to sea-level rise in the Skagit Delta. Northwest Science 90(1): 79-93. Doi: 10.3955/046.090.0107
A new issue of the journal Northwest Science is devoted to assessing climate change impacts on the Skagit River Basin in Washington. The issue features articles by scientists from across the Pacific Northwest as well as Larry Wasserman, Environmental Policy Director of the Swinomish Indian Tribal Community. The Skagit is responsible for over 30% of freshwater entering Puget Sound and is one of the most important sources of water in Western Washington. It is also home to all six salmon species that can be found in Puget Sound, which includes steelhead and Chinook salmon. Previous research studies have found that the Skagit basin is particularly vulnerable to climate change. There are approximately 394 glaciers in the eastern headwaters of the Skagit, and these glaciers are being affected by warming temperatures. Projected decreases in snowpack are expected to affect aquatic ecosystems, water supply and hydropower production. Fluvial processes, such as flow and sediment transport, are expected to shift and profoundly affect cold-water fish species, such as salmon, as well as leading to sea level rise via coastal flooding and erosion. Articles in the special issue discuss these issues affecting the Skagit River Basin, including articles on 1) impacts of glacial recession on summer streamflow, 2) impacts on hydrologic extremes, hydropower and sediment discharge, 3) low-flows in small lowland tributaries, 4) effects of sea level rise and storm surge on water levels, 4) vulnerability of tidal marshes to sea level rise, and 5) sensitivity of estuarine circulation to sea level rise.
Patterns of precipitation change and climatological uncertainty
Langenbrunner, B., Neelin, J. D., Lintner, B. R., & Anderson, B. T. (2015). Patterns of precipitation change and climatological uncertainty among CMIP5 models, with a focus on the midlatitude Pacific storm track. Journal of Climate, (2015).
Projections of changes in precipitation from global warming scenarios display disagreement at regional scales. Scientists from UCLA, the State University of New Jersey, and Boston University examined spatial patterns of disagreement in the simulated climatology and end-of-century precipitation changes in phase 5 of the Coupled Model Intercomparison Project (CMIP5) archive. The term principal uncertainty pattern (PUP) was used for any robust mode calculated when applying these techniques to a multimodel ensemble. This study found two PUPs in the tropics, one at the margins of the convection zones and the other in the Pacific cold tongue. Both modes appear to arise primarily from differences in the response to radiative forcing, distinct from internal variability. The leading storm-track PUPs for precipitation and zonal wind change exhibited similarities to the leading uncertainty patterns for the historical climatology, which indicated important and parallel sensitivities in the eastern Pacific storm-track. However, expansion coefficients for climatological uncertainties tended to be weakly correlated with those for end-of-century change
Deep groundwater aquifers respond rapidly to climate variability
Tess A. Russo, Upmanu Lall. Depletion and response of deep groundwater to climate-induced pumping variability. Nature Geoscience, 2017; 10 (2): 105 DOI: 10.1038/ngeo2883
A new study from Penn State University and Columbia University examined the unexpectedly rapid response of deep groundwater levels to climate change in recent years. Hydrologists Tess Russo and Upmanu Lall observed that deep groundwater levels respond to climate over timescales of less than one year, despite former expectations of a multi-year time lag. From this finding, the authors concluded that changes to deep groundwater levels must be driven by a factor other than precipitation changes. They hypothesized that the driving factor could be from changes in the pumping of aquifers from agricultural industries. As climate change impacts precipitation patterns and increases the frequency of drought, the irrigation of crops must be compensated through pumping deep groundwater. The authors emphasized the need to better understand how pumping impacts deep groundwater levels in order to know how to manage the nation’s water resources.
Assessing drought risk using climate models and paleoclimate data
Ault, T.R., J.E. Cole, J.T. Overpeck, G.T. Pederson, D.M. Meko. 2014. Assessing the risk of persistent drought using climate model simulations and paleoclimate data. Journal of Climate: 27, 7529-7549.http://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-12-00282.1
A new approach to drought and mega-drought projections for the Western U.S. provides important insights for analysis and planning. The authors used instrumental and paleoclimate data along with climate model projections to calculate drought risk because natural hydroclimate fluctuations tend to be more energetic at low (multidecadal to multicentury) than at high (interannual) frequencies. Their analysis indicates that megadrought risk is considerably higher than other state-of-the-art climate projections suggest, and that adaptation and mitigation strategies should account for the possibility of multidecadal drought worse than anything seen in the last 2000 years.
Evaluating climate model simulations of drought for the Northwestern U.S.
Abatzoglou, J.T. and Rupp, D.E. In press. Evaluating climate model simulations of drought for the northwestern United States. International Journal of Climatology. DOI:10.1002/joc.5046
Researchers from Oregon State and the University of Idaho developed a framework to help evaluate the fidelity of global climate models (GCMs) to simulate regional drought. They focused on the northwestern United States and found that model fidelity was generally higher for drought metrics evaluated with evapotranspiration versus precipitation and for seasonal/annual timescales versus multi-year timescales. They also found that models systematically underestimated the severity of regional drought in the region of focus. Their research aims to do two things: help those who use regional climate projections where drought plays an important role and highlight shortcomings of model simulations of hydroclimate variability.
Hydrologic landscape classification evaluates streamflow vulnerability to climate change in Oregon
Leibowitz, S. G., Comeleo, R. L., Wigington Jr., P. J., Weaver, C. P., Morefield, P. E., Sproles, E. A., and Ebersole, J. L.: Hydrologic landscape classification evaluates streamflow vulnerability to climate change in Oregon, USA, Hydrol. Earth Syst. Sci., 18, 3367-3392, doi:10.5194/hess-18-3367-2014, 2014
Classification can allow for evaluations of the hydrologic functions of landscapes and their responses to stressors. Here researchers demonstrate the use of a hydrologic landscape (HL) approach to evaluate vulnerability to potential future climate change at statewide and basin scales in the state of Oregon. The HL classification has five components: climate, seasonality, aquifer permeability, terrain, and soil permeability. We evaluate changes when the 1971–2000 HL climate indices are recalculated using 2041–2070 simulation results from the ECHAM (European Centre HAMburg) and PCM (Parallel Climate Model) climate models with the A2, A1b, and B1 emission scenarios. Changes in climate class were modest (4–18%) statewide. However, there were major changes in seasonality class for five of the six realizations (excluding PCM_B1): Oregon shifts from being 13% snow-dominated to 4–6% snow-dominated under these five realizations, representing a 56–68% reduction in snowmelt-dominated area… A major strength of the HL approach is that results can be applied to similarly classified, ungaged basins. Information resulting from such evaluations can help inform management responses to climate change at regional and basin scales without requiring detailed modeling efforts.
Restoring wetlands can lessen soil sinkage and greenhouse gas emissions
Jaclyn Hatala Matthes, Cove Sturtevant, Joseph Verfaillie, Sara Knox, Dennis Baldocchi. Parsing the variability in CH4flux at a spatially heterogeneous wetland: Integrating multiple eddy covariance towers with high-resolution flux footprint analysis. Journal of Geophysical Research: Biogeosciences, 2014; 119 (7): 1322 DOI: 10.1002/2014JG002642
Restoring wetlands can help reduce or reverse soil subsidence and reduce greenhouse gas emissions, according to research in California's Sacramento-San Joaquin River Delta. The study is one of the first to continually measure the fluctuations of both carbon and methane as they cycle through wetlands.
NorWeST adds Oregon Coast stream temperature climate scenarios & database to online availability
Stream temperature climate scenarios for the Oregon Coast developed from data the local aquatics community contributed are now available on the NorWeST website . The stream temperature database for this area is a compilation from dozens of resource organizations & hundreds of individuals & consists of 9,128 summers of monitoring effort at 3,472 unique stream sites. The NorWeST project is funded by the Great Northern and North Pacific LCC’s and the project goals are to develop a comprehensive regional database archive and a set of accurate, high-resolution stream climate scenarios for use in climate vulnerability assessments, temperature monitoring, interagency coordination, & stream research. The NorWeST products consist of three basic things (described below), all of which can be summarized, displayed, or queried in ArcGIS and other databases for ease of use. A file showing the scenarios for Oregon Coast streams under historic (1980s), 2040s, & 2080s conditions is attached to this email (flip through it to see an animated climate sequence).
Perspectives on the causes of exceptionally low 2015 snowpack in the western United States
Mote, P. W., D. E. Rupp, S. Li, D. J. Sharp, F. Otto, P. F. Uhe, M. Xiao, D. P. Lettenmaier, H. Cullen, and M. R. Allen (2016), Perspectives on the causes of exceptionally low 2015 snowpack in the western United States,Geophys. Res. Lett., 43, doi:10.1002/2016GL069965.
NWCSC Academic Director Phil Mote and colleagues recently published a report examining the “snow drought” of 2014-2015 in Washington and Oregon. The authors used a crowd-sourced superensemble of regional climate model simulations to compare human-induced causes to changes in sea surface temperature (SST) as contributions to the snow drought. Additionally, the study compared causes of the snow drought to the anomalous drought in California from 2011-2015. Findings from this study showed that SST anomalies contributed twice as much as anthropogenic effects, however both exhibited strong influences on the snow drought. Comparing this to the California drought, the authors conclude that both extreme events were exacerbated by human-induced rises in temperature.
Assessing the Effectiveness of Stream Restoration Monitoring in the Northwest
Stephen Bennett, George Pess, Nicolaas Bouwes, Phil Roni, Robert E. Bilby, Sean Gallagher, Jim Ruzycki, Thomas Buehrens, Kirk Krueger, William Ehinger, Joseph Anderson,Chris Jordan, Brett Bowersox & Correigh Greene. 2016. Progress and Challenges of Testing the Effectiveness of Stream Restoration in the Pacific Northwest Using Intensively Monitored Watersheds. Fisheries. 41(2):92-103.
The Pacific Northwest, due to its large populations of endangered anadromous fish populations (salmon and steelhead), has seen major efforts toward implementing stream restoration. While these efforts are seen as ecologically sound, little research has been done to understand the relationship between freshwater habitat improvement and increased fish populations. Therefore, 17 watershed projects have been implemented to test the validity of this relationship. In this recently published article, Bennett et al. (2016) assessed the scope and status of these 17 projects and reported current challenges and suggestions for improving experimental designs that fit into an adaptive management framework. Based on their assessment, the authors confirmed that intensive monitoring of watersheds is a sound approach for measuring the success of stream restoration, though they found funding and coordination between participants and stakeholders to be significant challenges.
Incorporating climate change projections into riparian restoration planning and design
Perry, L.G., Reynolds, L.V., Beechie, T.J., Collins, M.J. and Shafroth, P.B. 2015. Incorporating climate change projections into riparian restoration planning and design. Ecohydrology DOI: 10.1002/eco.1645
Riparian restoration may help shade and cool streams to mitigate the impacts of climate change and other human disturbances. However, climate change may alter which restoration methods are most effective and which restoration goals can be achieved. In this review the authors discuss and provide examples of how climate change might be incorporated into restoration planning at the key stages of assessing the project context, establishing restoration goals and design criteria, evaluating design alternatives and monitoring restoration outcomes. Given high uncertainty in future conditions, planners will need to consider multiple potential future scenarios, implement a variety of restoration methods, design projects with flexibility and plan to respond adaptively to climate change.
Carbon dynamics in a headwater stream located in the Cascade Mountains of Oregon
Corson-Rikert, H. A., Wondzell, S. M., Haggerty, R. and Santelmann, M. V. 2016. Carbon dynamics in the hyporheic zone of a headwater mountain stream in the Cascade Mountains, Oregon. Water Resour. Res.. Accepted Author Manuscript. doi:10.1002/2016WR019303
Researchers from Oregon State University recently published a study examining carbon dynamics in the hyporheic zone (region beneath the streambed) of a headwater stream in western Oregon. Headwaters are significant areas of research because they are at the exchange between terrestrial and aquatic ecosystems, and therefore play a critical role in the carbon cycle. The researchers collected monthly water samples as well as other physical and chemical characteristics of the headwaters during baseflow conditions from July to December 2013. They found that Dissolved Organic Carbon (DOC) decreased and Dissolved Inorganic Carbon (DIC) increased during baseflow period, making the hyporheic zone a net source of DIC to the stream. The authors successfully characterized the carbon dynamics of the headwater stream and concluded by extrapolating the role of the hyporheic zone of headwaters for carbon transport and transformation.
Understanding the California drought as an extreme value:
Robeson, SM. Revising the recent California drought as an extreme value. Geophys Res Lett 42, doi: 10.1002/2015GL064593
This study uses the statistical technique of extreme value theory to understand the probability of how often a drought as severe as California’s is expected to occur. The author, Scott Robeson of the University of Indiana at Bloomington, draws upon the method of Griffin and Anchukaitis (2014) but shows how their method had an error because it did not account for the respective areas (in square kilometers) of Central and Southern California. He uses observational data from 1895 – 2014 on the Palmer Drought Severity Index (PDSI) from tree rings to estimate the occurrence of droughts beginning in the year 800. Robeson finds that the 2014 drought in California had a return period of 140-180 years, e.g. a probability of occurring every 140 – 180 years. However, if the drought from 2012 through 2014 is included, rather than just the year 2012, the probability decreases to a 10,000 year event, or occurring every 10,000 years. If this year is also included, the probability of the drought occurring decreases to zero. Hence they conclude that the drought is completely without precedent.
Shifts from Snow to Rain Precipitation Regimes and their Impact on Western Juniper
Niemeyer, R. J., Link, T. E., Seyfried, M. S., & Flerchinger, G. N. (2016). Surface water input from snowmelt and rain throughfall in western juniper: Potential impacts of climate change and shifts in semi‐arid vegetation.Hydrological Processes.
A new study, led by former NW CSC Graduate Fellow Ryan Niemeyer, looks at the impacts of shifting precipitation regimes due to climate change on western juniper. Specifically, it looks at impacts on surface water input due to changes in throughfall, meaning the amount of snow that is not blocked from the land-surface due to interception by trees. In addition to juniper, they also examined impacts on mountain big sagebrush and low sagebrush plant communities. The authors used a simultaneous heat and water model to simulate energy and heat fluxes and found that juniper reduced the amount of surface water input relative to sagebrush. Warming temperatures had a relatively minimal impact in terms of reducing surface water input for juniper and sagebrush. Their results are important given potential vegetation shifts due to climate change and the need to understand how shifting precipitation regimes will impact surface water input.
Low Mountain Snowpack Raises Water-Supply Fears in Washington
Washington’s snowpack is approximately half its average, which could prove problematic later in the year when the state relies on snowmelt for water supply. On January 1st, the Olympics and Central Puget Sound Cascades snow pack levels were only 27% and 34% of average respectively. The low snow pack levels may seem surprising because of recent of heavy rain. However, high temperatures in the region are what prevented the precipitation from adding significantly to the snowpack. Snowmelt is a main contributor to the Cedar River Watershed, which provides approximately 70% of the drinking water to 1.4 million Seattle-area residents.
Evaluating drought indices for tracking interannual streamflow variability in the PNW
John T. Abatzoglou, Renaud Barbero, Jacob W. Wolf, and Zachary A. Holden, 2014: Tracking Interannual Streamflow Variability with Drought Indices in the U.S. Pacific Northwest. J. Hydrometeor, 15, 1900–1912. doi: http://dx.doi.org/10.1175/JHM-D-13-0167.1
This study examines various indices and models used for monitoring interannual streamflow variability in the Pacific Northwest. Standardized precipitation index, standardized precipitation evapotranspiration index (SPEI), Palmer drought severity index, and water balance runoff (WBR) model output were correlated to water-year runoff for 21 unregulated drainage basins in the Pacific Northwest. Indices calculated using high-resolution PRISM climate surfaces explained 10-15% percent more variance in streamflow than metrics derived from coarser-resolution datasets. The paper addresses various ways to monitor hydro-climactic variables at local and regional scales and enables resource managers, landowners, and planners to see the additional benefit of using higher spatial resolution climate layers to account for the complex topography of the PNW.
Slower snowmelt in a warmer world
Musselman, K.N., Clark, M.P., Liu, C., Ikeda, K. and Rasmussen, R., 2017. Slower snowmelt in a warmer world. Nature Climate Change. doi:10.1038/nclimate3225
Based on observations that shallower snowpack melts earlier and at lower rates than deeper, later-lying snow-cover, a team of scientists tested their hypothesis that a warmer climate would reduce snowmelt rates. Using climate model simulations, the authors examined the effect of warmer temperatures on snowmelt and found that the fraction of meltwater volume produced at high snowmelt rates was greatly reduced under warmer conditions. The authors concluded that this phenomenon is due to the shift of snowmelt season toward a time of lower available energy, which consequently reduces snow-covered areas exposed to enough energy to drive snowmelt by approximately 64 percent.
Artificial amplification of warming trends across the mountains of the western United States
Oyler, J.W., Dobrowski, S.Z. Ballantyne, A.P., Klene, A.E., Running, S.W. 2015. Artificial amplification of warming trends across the mountains of the western United States. Geophysical Research Letters 42, 153-161. doi:10.1002/2014GL062803.
A new study suggests that elevation dependent warming may not be occurring as is suggested by observational data. Observations from the mountain climate station network in the Western United States suggest that some higher elevation areas are warming faster than lower elevation areas. This study evaluates temperature observations from the climate network sites and finds that the extreme warming observed at higher elevations is a result of systematic artifacts and not climatic conditions. The authors find that climate data that is widely used for model simulations propagate these temperature trends, which impacts the ability for studies to accurately model climate change impacts in mountainous parts of the Western US.
Developing a representative snow monitoring network in a forested mountain watershed
Gleason, K. E., Nolin, A. W., & Roth, T. R. (2016). Developing a representative snow monitoring network in a forested mountain watershed. Hydrology and Earth System Sciences Discussions Hydrol. Earth Syst. Sci. Discuss., 1-26. doi:10.5194/hess-2016-317
Current snow monitoring networks may not be representative of basin-scale distributions of snow water equivalent (SWE), especially in areas where forests and snowpacks are changing. To address this issue, researchers conducted a study to determine the key physiographic drivers of SWE; classify the landscape based on those physiographic drivers; and use that classification to identify a parsimonious set of monitoring sites in a forested watershed in the western Oregon Cascades mountain range. Once this was established, snow monitoring networks were put into place and usable data was collected over a five-year period. The monitoring network provides a valuable and detailed dataset of snow accumulation, snow ablation, and snowpack energy balance in forested and open sites from the rain-snow transition zone to upper seasonal snow zone in the western Oregon Cascades.
Identifying & protecting climate refuge lakes for coldwater fishes
The climate is changing and fish populations are changing in response (blogs 32, 34, 35, 42). Managing and conserving efficiently this century means having a good sense of where it’s all headed and committing limited conservation resources accordingly. Committing to the wrong places risks being run over by the climate change train or squandering resources on populations that would have been fine regardless of what the climate does (blog #52). The sweet spot lies between the two extremes and figuring out where our investments will tip the balance toward more desirable outcomes later this century. So as alluded in the previous blog (#56), this time we’re highlighting a set of related studies that constitute the current global gold standard in terms of developing the science, information, and management policies for making those commitments for one species in one landscape…
Climate-related changes of soil characteristics affect bacterial community composition and function of high altitude and latitude lakes
Rofner, C., Peter, H., Catalán, N., Drewes, F., Sommaruga, R. and Pérez, M. T. (2017), Climate-related changes of soil characteristics affect bacterial community composition and function of high altitude and latitude lakes. Global Change Biology, 23: 2331–2344. doi:10.1111/gcb.13545
Climate change is driving vegetation range shifts in high altitude and latitude regions that will ultimately alter the distribution of soil organic matter. Once mobilized, this organic matter may rapidly alter the composition and function of lake bacterial communities. In this study researchers experimentally simulated potential climate-change effects on lake organic matter by exposing bacterioplankton of two lakes above treeline (one subarctic and one alpine) to soil organic matter. They then tracked changes in bacterial community composition, diversity and function for 72 h. In a subarctic lake, soil organic matter reduced bulk and taxon-specific phosphorus uptake. These effects were less pronounced in an alpine lake, suggesting that soil properties and water temperature shaped the magnitude of response. The rapid bacterial succession observed in both lakes indicates that certain taxa directly benefited from soil sources. This work suggests that climate-induced changes in soil characteristics affect bacterioplankton community structure and function, and in turn, the cycling of carbon and phosphorus in high altitude and latitude aquatic ecosystems.
Low snow and warming temperatures eat away at Northwest glaciers
The Seattle Times reports on research into the state of glaciers in the Northwest. Mauri Pelto, a Nichols College glaciologist, has been studying Washington’s glaciers for over thirty years. Pelto recently completed an annual survey of glaciers in the North Cascades and stated that he and his research team found bare ice and gushing meltwater where glaciers typically would be covered in snow. He estimated that glaciers would lose 5 to 10% of volume before the summer was over, the single largest volume loss in the past 50 years. Measurements taken by the Nooksack tribe showed that the glacier, which feeds into the Nooksack River, was losing a foot-thick layer from the surface of the glacier every week. The Nooksack tribe has funded a number of studies to forecast the future of glaciers that feed the Nooksack River because of concerns over salmon, said the Nooksack water resources manager, Oliver Grah. Although this year has been bad, glaciers in the Northwest have been losing volume – between 25 to 40% - since the mid-1980s, Pelto said.
Mixed populations and annual flood frequency estimates in the western US: the role of atmospheric rivers
Barth, N. A., Villarini, G., NAyak, M. and White, K. (2016), Mixed populations and annual flood frequency estimates in the western United States: The role of atmospheric rivers. Water Resour. Res.. Accepted Author Manuscript. doi:10.1002/2016WR019064
Researchers from the University of Iowa recently published their study examining the spatial and fractional contribution of atmospheric rivers in annual peak flow data. The study used 30 years of data from 1,375 streamgage sites to identify regions in which flooding was impacted by atmospheric rivers through the western United States. Findings showed the Pacific Northwest and the coast of northern California to have, on average, the highest fraction (~80-100%) of peak flows induced by atmospheric rivers. Localized regions, such as the Columbia River Basin, tended to experience a wider range of impact. In contrast to the Pacific Northwest and the northern California coast, Montana, Wyoming, Utah, Colorado and New Mexico exhibited no impact from atmospheric rivers.
Climate-Aquatics Bonus Blog #60: New report describes data collection protocols for continuous monitoring of temperature & flow in wadeable streams
More stream-climate data is the simplest way to decrease uncertainties…
Low snowpacks of 2014, 2015 may become increasingly common
Sproles, E. A., Roth, T. R., and Nolin, A. W.: Future snow? A spatial-probabilistic assessment of the extraordinarily low snowpacks of 2014 and 2015 in the Oregon Cascades, The Cryosphere, 11, 331-341, doi:10.5194/tc-11-331-2017, 2017.
A new study suggests that the historically low Cascade Mountain snowpack levels in 2014 and 2015 could become more common if average temperatures warm as little as two degrees Celsius. The low snowpack levels were linked to warmer temperatures and not a lack of precipitation. Based on simulations of previous and predicted snowpack, the study suggests that by mid-century, years like 2015 may happen about once a decade, while snowpack levels similar to 2014 will take place every 4-5 years. Results of the study, which was supported by the National Aeronautics and Space Administration (NASA) and the National Science Foundation, were recently published the journal The Cryosphere.
The 2014/2015 snowpack drought in Washington State and its climate forcing
Fosu, B.O., and Coauthors, 2016: The 2014/2015 Snowpack Drought in Washington State and its Climate Forcing [in “Explaining Extremes of 2015 from a Climate Perspective”]. Bull. Amer. Meteor. Soc., 97 (12), S19–S24, doi:10.1175/BAMS-D-16-0149.
The American Meteorological Society has released its 5th annual report of extreme events from the previous year. Included in the report is a section titled “The 2014/2015 Snowpack Drought in Washington State and its Climate Forcing.” Authored by Boniface Fosu and colleagues, the article discussed the “snowpack drought” of 2015, where an alteration in temperature caused a reduction in snowfall and an increase in rainfall, and consequently reduced snowpack that led to drought conditions. The authors concluded that a significant portion of the change in precipitation was due to changes in circulation patterns that were associated with the North Pacific climate variability. Specifically, the authors highlighted the North Pacific Index, a low frequency variability, as the driver for the cyclical relationship between temperature and precipitation.
First EPA National Wetland Assessment
The EPA has released its first ever nationwide report on the health of U.S. wetlands, finding that one-third of them are in poor condition. The report measured the biological, physical, and chemical stresses acting upon U.S. coastal marshes, prairie potholes, central plain meadows, and other natural areas encompassed by the definition of ‘wetland’. Concerning wetlands in the Western U.S., the report found that 72% have high or very high levels of stress from nonnative plants. Additionally, relative to the rest of the country, many wetland areas in the western U.S. tested high on the index for contamination of heavy metals. Read the full National Wetland Condition Assessment using the link below.
Projected changes in snowfall extremes and interannual variability of snowfall in the western United States
Lute, A. C., J. T. Abatzoglou, and K. C. Hegewisch (2015), Projected changes in snowfall extremes and interannual variability of snowfall in the western United States, Water Resour. Res., 51, 960–972, doi:10.1002/2014WR016267.
Projected warming will have significant impacts on snowfall accumulation and melt, with implications for water availability and management in snow-dominated regions. Changes in snowfall extremes are confounded by projected increases in precipitation extremes. Three scientists from the University of Idaho bias-corrected downscaled climate projections from 20 global climate models to montane Snowpack Telemetry stations across the western United States. The study assessed mid-21st century changes in the mean and the variability of annual snowfall water equivalent (SFE) and extreme snowfall events. The researchers found that changes in the magnitude of snowfall event quantiles were sensitive to historical winter temperature. At climatologically cooler locations, such as in the Rocky Mountains, changes in the magnitude of snowfall events mirrored changes in the distribution of precipitation events, with increases in extremes and less change in more moderate events. By contrast, declines in snowfall event magnitudes were found for all quantiles in warmer locations. Common to both warmer and colder sites was a relative increase in the magnitude of snowfall extremes compared to annual SFE and a larger fraction of annual SFE from snowfall extremes. The coefficient of variation of annual SFE increased up to 80% in warmer montane regions due to projected declines in snowfall days and the increased contribution of snowfall extremes to annual SFE. In addition to declines in mean annual SFE, more frequent low-snowfall years and less frequent high-snowfall years were projected for every station.
Evaluating soil moisture in CMIP5 simulations
Yuan, S. and Quiring, S. M. 2016. Evaluation of soil moisture in CMIP5 simulations over contiguous United States using in situ and satellite observations. Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-477, in review.
In this recent study, climate scientists Shanshui Yuan and Steven Quiring report their evaluation of soil moisture simulations during the warm season in the Coupled Model Intercomparison Project Phase 5 (CMIP5), comparing in situ and satellite soil moisture data to the simulations of over 14 CMIP5 models. The authors found the CMIP5 models to be successful at capturing the seasonal variability in soil moisture over the conterminous United States, however tended to overestimate the magnitude of both near-surface (1-10 cm) and soil-column (1-100 cm) soil moisture in the western U.S. and underestimate the magnitude in the eastern U.S. Three models (CESM1, CCSM4, and GFDL-ESM2M) performed best in the near-surface and soil-column layers, while HadGEM2-ES only performed best in the soil-column layer. Overall, the report showed large variation in soil moisture simulations across the models, especially in the near-surface soil layer.
Impacts of 21st century climate change on hydrologic extremes in the Pacific Northwes
Tohver, I.M., A.F. Hamlet, and S-Y Lee. 2014. Impacts of 21st century climate change on hydrologic extremes in the Pacific Northwest region of North America. Journal of the American Water Works Association 1-16. DOI: 10.1111/jawr.12199
Using a physically based hydrologic model and an ensemble of statistically downscaled global climate model (GCM) scenarios produced by the Columbia Basin Climate Change Scenarios Project, this study examines the nature of changing hydrologic extremes (floods and low flows) under natural conditions for about 300 river locations in the Pacific Northwest. The combination of warming and shifts in seasonal precipitation regimes results in increased flooding and more intense low flows for most basins. Flood responses depend on average mid-winter T and basin type. Mixed-rain and snow basins, with average winter temperatures near freezing, typically show the largest increases in flood risk because of the combined effects of warming (increasing contributing basin area) and more winter precipitation. Decreases in low flows are driven by loss of snowpack, drier summers, and increasing evapotranspiration in the simulations.
A first step in prioritizing riparian corridors for climate adaptation planning
Riparian areas are key targets for conservation efforts aimed at promoting biological resilience to climate change. However, few methods are available to managers to prioritize specific riparian areas when developing climate adaptation strategies. Current methods typically use riverine connectivity as a coarse proxy for riparian connectivity and do not account for variability in habitat quality, which should influence species range shifts and availability of refugia. To improve on these methods, Dr. Meade Krosby at the University of Washington’s Climate Impacts Group and her colleagues completed a fine-resolution analysis, which identifies potential riparian areas with characteristics (e.g., high canopy cover, large temperature gradient) expected to benefit species. They also integrate results from across scales—from local watersheds to the entire Pacific Northwest (USA).
The researchers emphasize the analysis' value as a first step toward identifying Pacific Northwest riparian areas that are most likely to promote biological resilience to climate change. Though they acknowledge the analysis has limitations that must be considered before its application, the researchers intent is to greatly improve the ability of natural resource managers to prioritize riparian corridors in climate adaptation planning.
Implications of glacio-hydrological change for water resources in the Hood River Basin, OR
Frans, C., Istanbulluoglu, E., Lettenmaier, D. P., Clarke, G., Bohn, T. J., & Stumbaugh, M. 2016. Implications of decadal to century scale glacio‐hydrological change for water resources of the Hood River Basin, OR USA. Hydrological Processes.
In partially glacierized watersheds, mountain glaciers are an important source of water. Precipitation patterns are often highly season, with snow and ice masses redistributing seasonal precipitation when there are few other sources of streamflow. Consequently, glaciers provide a natural buffering of low flows. However, systems that rely on this buffering are particularly vulnerable to climate change. This new study, led by Chris Frans, formerly of the University of Washington and now at the US Army Corps of Engineers, looks at the evolution of glacier melt contribution in watershed hydrology over a 184-year period, from 1916-2099, incorporating two future climate scenarios (RCP 4.5 and 8.5) for the Hood River Basin in Northwest Oregon. The authors use a coupled hydrological and glacier dynamics model to perform continuous simulations of glaciological processes (including mass accumulation and ablation, lateral flow, and heat conduction). These processes are also key for other hydrological processes, such as snow dynamics and evapotranspiration. They find that the contribution of glacier melt to basin water supply was 79% in some parts of the basin historically. However, projected changes in climate will lead to a 14-63% or 18-78% reduction (RCP 4.5 and 8.5, respectively) in dry season discharge. The largest losses will occur at upland locations that were historically dominated by glacier melt and seasonal snow melt. Some losses will be modulated by supraglacial debris on the Hood River glaciers, which slows glacier recession. Additionally, the authors find large decadal variability in glacier melt, which underscores the need to use long time series in studying glacier recession.
Regional trends in snowfall frequency in the contiguous United States
Kluver, D. and Leathers D. 2015. Regionalization of snowfall frequency and trends over the contiguous United States. International Journal of Climatology 35: pp. 4348-4358. doi: 10.1002/joc.4292
In this new study, the authors explore changes in regional variations of snowfall in the United States from 1930-2007. The authors draw on a subset of 440 stations from the US Historical Climatology Network for snowfall data and use statistical techniques to cluster similar stations together based on the main modes of variation in snowfall frequency. They find seven unique snowfall regions that correlate with storm tracks across the US. These regions include the southeast, south central plains and southwest, the Ohio River Valley and mid-Atlantic, the Pacific Northwest, and three subregions in the Upper Midwest. The Pacific Northwest is experiencing statistically significant declines in greater than median snowfall frequencies, as well as statistically significant decreasing trends in the 75th and 90th quantiles of snowfall frequency. Snowfall frequency in the Pacific Northwest is strongly correlated with the Pacific Decadal Oscillation, the Pacific North American Oscillation and El Nino. They also observe a strong negative correlation with Northern Hemispheric annual temperature. The authors imply that the statistically significant differences observed in snowfall frequency in the Pacific Northwest are due to some combination of warmer temperatures and differences in PDO, El Nino and PNA patterns.
Climate Change, Crowd-Sourcing, and Conserving Aquatic Biotas in the Rocky Mountains This Century
July/August issue of the USFS’ Science You Can Use: http://www.fs.fed.us/rm/science-application-integration/publications/
The July/August issue of the USFS Rocky Mountain Research Station’s Science You Can Use publication is devoted to this topic. Abstract: Climate change is causing rapid changes to stream habitats across the Rocky Mountains and Pacific Northwest as warmer air temperatures and changes in precipitation increase stream temperatures, alter stream hydrology, and increase the extent and magnitude of natural disturbances related to droughts and wildfires. These changes are affecting trout, salmon, and other fish populations, many of which are already subject to substantial non-climate stressors. Fish habitats at lower elevations—near the downstream edges of species distributions—are particularly vulnerable. However, three Rocky Mountain Research scientists are conducting research and developing applied management tools that harness the power of crowd-sourcing to generate information and create opportunities for collaboration and resource allocation decisions that may help to conserve some of the aquatic biotas currently at risk. This is enabling adaptation to move forward at a scale and pace more appropriate to the challenges posed by climate change.
Factors Impacting Flow of Headwater Stream Networks in Central Idaho
Whiting, John A. and Sarah E. Godsey, 2016. Discontinuous headwater stream networks with stable flowheads, salmon river basin, Idaho. Hydrological Processes, in press. doi: 10.1002/hyp.10790
A new study from Idaho State University examined the hydrologic mechanisms affecting changes to the flow path of streams in Central Idaho's Frank Church-River of No Return Wilderness. Whiting & Godsey (2016) presented survey data of active drainage networks in four headwater streams. The authors found that stream discharge varied with the total length of the active drainage networks, though less so than past studies have shown. The study also compared active drainage network length along entire flow paths of the watershed and found that a majority of the changes in length were due to downstream discontinuities, with more stable flow paths occurring near the stream’s head. Additionally, geologic characteristics were examined for the various watersheds and found that streamflows originating below 2,200 m were controlled by bedrock and thus more stable than those originating at higher elevations and surrounded by less compact soils.
EPA Announces Climate Adjustment Tool for the Storm Water Management Model
EPA's Storm Water Management Model (SWMM) is widely used throughout the world and is considered the "gold standard" in the design of urban wet-weather flow pollution abatement approaches. It is a dynamic hydrology-hydraulic water quality simulation model used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas, and allows users to include any combination of low impact development (LID)/green infrastructure controls to determine their effectiveness in managing stormwater and sewer overflows. The new Climate Adjustment Tool (SWMM-CAT) is a simple to use software utility that applies monthly climate adjustment factors onto historical precipitation and temperature data to consider potential impacts of future climate on stormwater. Learn more and access the tool and download the SWMM-CAT user’s guide.
Population Fluctuations of Coastal Cutthroat Trout in Irely Creek, Washington
In the Irely Creek watershed (upper Quinault River drainage) within Olympic National Park, coastal cutthroat coexists with anadromous coho salmon and two resident-fish and several amphibian species. During 2001-2002, cutthroat redds and fry were abundant in the mainstem, particularly in its middle segment, with escapement estimates being 48-106. More recently, the population has declined by an order of magnitude, reflecting summer/fall droughts that have often dried up adult habitat in Irely Lake. Although redd counts have risen when summer/fall seasons have been wetter during 2003-2010, they haven’t reached 2001-2002 counts via regular lake dry-outs, including two consecutive dry-outs during 2002-2003. Hence, the population is showing an overall downward trend with some smaller-scale oscillations coupled with escapement estimates during 2003-2010 ranging from 4 to 32.
Calculating the role of lakes in global warming
Biologist Kevin Rose from the Rensselaer Polytechnic Institute and colleagues are undergoing a large-scale study examining the potential impacts of rising temperatures on the carbon cycle of lakes. Lakes are a major part of the carbon cycle. The amount of carbon dioxide and methane that a lake emits depends on temperature, making Rose’s research question significant for understanding how carbon emission from lakes will change with future warming. Funded by the National Science Foundation, the researchers will project future weather conditions for 2000 lakes over the next 90 years. The simulations will include changes in weather, water temperature and carbon and methane emissions. The authors will then combine this data with known physical, chemical and biological characteristics of the individual lakes in order to produce a large-scale dataset of predicted changes to lake thermal characteristics such as the temperature profile, depth of temperature stratification, and ice cover. Such thermal features of these lakes will lead to the determination of lakes as either a source or sink of carbon under future warming conditions.
American Rivers has added the Green-Duwamish River to it’s most endangered list
American Rivers, an organization involved in protecting, restoring, and conserving water systems through the U.S. has added Washington’s Green-Duwamish River to its 2016 list of the country’s ten most endangered rivers. To make the list, the river must play a significant role for the surrounding human and natural community, be impacted by climate-induced factors, and have a proposed action plan in the coming year that could greatly improve the health of the river. For the Green-Duwamish River, this action plan concerns the Army Corps of Engineer’s construction of a salmon passage that would mitigate river obstruction caused by dams. Called the Howard Hanson juvenile fish passage system, the Army Corps and NOAA are proposing a new project that would begin in 2021. In addition, a management and funding plan for the river has been proposed that would integrate local, state, and federal efforts to clean up the river. The actions taken in the next year will have major consequences for the future health of the river.
Detectability of change in winter precipitation within mountain landscapes: Spatial patterns and uncertainty
Silverman, N. L., & Maneta, M. P. (2016). Detectability of change in winter precipitation within mountain landscapes: Spatial patterns and uncertainty. Water Resources Research Water Resour. Res. doi:10.1002/2014wr016493
A study was conducted in the mountainous terrain of Western Montana to determine the minimum amount of change in winter precipitation that is necessary to be detected. To gather data, the researchers looked at historic regional climate model simulations and ground observations and compared the values to the best estimates of precipitation. The study found that approximately 65% of the significant increases in winter precipitation are undetectable. Areas where change can be detected are largely controlled by topographic features. Elevation and aspect are key characteristics that determine whether or not changes in winter precipitation can be detected. The study also found that undetected increases in winter precipitation at high elevation will likely remain as snow under climate change scenarios. This means that there is potential for these areas to offset snowpack loss at lower elevations and alleviate the effects of climate change on water resources.
Storm Surge Inundation & Scenario-Based Projected Changes Map
Developed by the EPA, the storm surge inundation map is an interactive map illustrating the current worst-case storm surge and inundation scenarios on the American Gulf and Atlantic coasts. The map incorporates data layers from FEMA’s 100 and 500 year flood maps, NOAA’s Sea, Lake and Overland Surge from Hurricanes (SLOSH), and the National Hurricane Center's coastal county hurricane strike maps. The second map, EPA’s scenario-based projected changes map, is an online map that provides access to localized scenarios of projected changes in annual total precipitation, precipitation intensity, annual average temperature, 100-year storm events, and sea-level rise from EPA’s Climate Resilience Evaluation and Awareness Tool.
Warming Favors Invasive Fish over Native Trout and Salmon
Climate change is rapidly altering freshwater systems across the Northwest as air temperatures warm, patterns of precipitation and snowmelt change, and droughts and wildfires increase in frequency and intensity. Many species, including the Chinook salmon, westslope cutthroat trout, and native bull trout are at risk. Fortunately, managers still have a time to implement conservation measures with the potential to yield high future dividends. Here are three stories illustrating how climate researchers are helping.
The Beaver Restoration Guidebook- Working with Beaver to Restore Streams, Wetlands, and Floodplains:
The North Pacific Landscape Conservation Cooperative partnered with U.S. Fish & Wildlife, NOAA, Portland State University, and the U.S. Forest Service to develop a comprehensive guide on using beaver for stream restoration. The goal of this guidebook, which was just released, is to provide an accessible, useful resource for anyone involved in using beaver to restore streams, floodplains, wetlands, and riparian areas. It provides a practical synthesis of the best available science, an overview of management techniques, and case studies from throughout the western US. Target audiences are landowners, biologists, engineers, scientists, foresters, farmers, ranchers, the regulatory and funding communities, and others interested in how beaver activity can be effectively used to restore riparian habitat and improve water quality. The information contained in the guide is meant to inform decisions on fish and wildlife habitat restoration and management, range land improvement, wetland management, mitigation, transportation system planning and maintenance, and water management.
Evaluation of snowfall products over the western US
Wen, Y., Kirstetter, P., Gourley, J.J., Hong, Y., Behrangi, A. and Flamig, Z., 2017. Evaluation of MRMS snowfall products over the western United States. Journal of Hydrometeorology.
This recently published study assessed the success of Multi-Radar Multi-Sensor (MRMS) quantitative estimates of snow rate using Snow Telemetry (SNOTEL) daily snow water equivalent (SWE) datasets. The team of researchers found that MRMS displayed limited effectiveness in detecting very light snow (accumulation <5 mm), however exhibited good detectability of accumulation greater than 10 mm. This evaluation showed an underestimation bias of the monitoring system and the authors concluded that this bia is likely due to a problem with the calculation of the relationship between reflectivity and SWE intensity.
Groundwater slowly being depleted in the United States
Konikow, L.F. 2015. Long-Term Groundwater Depletion in the United States. Groundwater 53, 1, 2-9.
Between 1900 – 2008, the volume of groundwater stored below the United States decreased by almost 1000 cubic kilometers. The areas with the highest amount of storage depletion include the High Plains aquifer the Mississippi Embayment section of the Gulf Coastal Plain aquifer system, and the Central Valley in California. The rate of depletion has accelerated since 2000. Leonard Konikow, the author of the study, introduces a new parameter for studying groundwater depletion, ‘depletion intensity’, to understand how storage changes are occurring geographically. He found that the Central Valley in California had the highest depletion intensity. Groundwater depletion can have a wide range of harmful effects, including reduced well yields, reduced base flow to springs, streams and other surface water bodies, and loss of wetlands. It is also responsible for sea level rise, and Konikow found that groundwater depletion in the United States could explain 1.4% of observed sea level rise that occurred during the study period.
Snowmelt rate dictates streamflow
Barnhart, T. B., N. P. Molotch, B. Livneh, A. A. Harpold, J. F. Knowles, and D. Schneider. 2016. Snowmelt rate dictates streamflow, Geophys. Res. Lett., 43, 8006–8016, doi:10.1002/2016GL069690.
A new study from the University of Colorado looked at the relationship between snowmelt rate and streamflow generation using the Budyko framework, a mechanism used to compare streamflow and evaporative partitioning of different watersheds for a given amount of available energy and precipitation. The authors quantified an ensemble of “Budyko streamflow anomalies” and correlated them with simulated baseflow efficiency and simulated snowmelt rate. These findings support a possible streamflow generation mechanism where greater snowmelt rates increase subsurface flow. Significance of the mechanism detected in this study includes the possibility of decreased streamflow production under slower snowmelt conditions.
Climate warming contributes to native and invasive trout hybridization
Nature Clim. Change, 2014/07/, Vol 4, Issue 7, pp 620- 624, http://dx.doi.org/10.1038/nclimate2252
Results from a study conducted by Dr. Clint Muhlfeld, US Geological Survey, with funding support from the Great Northern LCC, was recently published in the journal Nature Climate Change. The paper reports that rapid climate warming contributes to hybridization between native and invasive trout species. Muhlfeld and his collaborators examined long-term genetic monitoring data with high-resolution climate and stream temperature predictions. Their findings indicate that invasive hybridization could result in genomic extinction for many native species.
Glaciers rapidly shrinking and disappearing: 50 years of glacier change in Montana
U.S. Geological Survey. "Glaciers rapidly shrinking and disappearing: 50 years of glacier change in Montana." ScienceDaily, 10 May 2017.
A recent report from the U.S. Geological Survey (USGS) reveals the dramatically reduced sizes of 39 glaciers in Montana since 1966, with some decreasing by as much as 85 percent. Researchers from the USGS and Portland State University reported that, on average, glaciers in Montana have been reduced by 39 percent, and only 26 of them are still large enough to be considered glaciers. In addition to ecological effects on aquatic species with consequent changes in water volume, temperature and run-off, this glacial decline could also have large impacts on Montana’s tourism industry. This data is part of a larger, ongoing USGS study of glaciers in Montana, Alaska and Washington, which seeks to help scientists understand how climate patterns impact glaciers in different mountain environments.
Nursery Functions of U.S. West Coast Estuaries
Hughes, B.B., M.D., Levey, Brown, J.A., Fountain, M.C., Carlisle, A.B., Litvin, S.Y., Greene, C.M., Heady, W.N., Gleason, M.G. 2015. Nursery functions of U.S. west coast estuaries: the state of knowledge for juveniles of focal invertebrates and fish species. http://www.pacificfishhabitat.org/media/pmepsokreport/tnc_ca_fishnurseries_lowres.pdf
This report synthesizes existing scientific literature, expert opinion, and geospatial data on the presence of juveniles and potential nursery role of West Coast estuaries (in Washington, Oregon, and California) for fifteen ecologically, economically, and culturally important species. This report also evaluated many threats to estuarine habitats (including climate change) and the nursery role they provide to these focal species. 19 threats were analyzed, and habitat loss was the most prevalent threat among the 15 focal species.
Modeling Analysis: From Spatially Variable Streamflow to Distributed Hydrological Models
Fenicia, F., Kavetski, D., Savenije, H. H. G. and Pfister, L. (2016), From spatially variable streamflow to distributed hydrological models: Analysis of key modeling decisions. Water Resour. Res.. Accepted Author Manuscript. doi:10.1002/2015WR017398
One of the key challenges in modeling hydrological processes is how to divide up a given domain. For example, oftentimes spatially explicit modeling is needed in order to provide spatially explicit predictions of streamflow for a given catchment. In this study, the authors explore the development of distributed hydrological models, using the Attert catchment in Luxembourg as a case study. The Attert catchment is a 300-square-kilometer catchment with 10 nested subcatchments, each with different streamflow dynamics. The study divides up the catchments into hydrologic response units (HRUs) at a 6-hourly time step. Several model structures are used. Results suggest that geology-based HRUs are better at capturing spatial variability of streamflow than topography-based HRUs, which points to a more significant role of geology in determining streamflow dynamics (at least in this catchment). Although the study only examines streamflow dynamics for the Attert catchment, the methodology is applicable elsewhere in understanding which model structures are most appropriate for characterizing dominant hydrologic processes.
Hydrologic Debates on Stationarity Due to Climate Change Impacts
Milly PCD, Betancourt J, Falkenmark M, Hirsch RM, Kundzewicz ZW, Lettenmaier DP, Stouffer RJ, Dettinger MD, Krysanova V (2015) On Critiques of “Stationarity is Dead: Wither Water Management?” Water Resources Research 51. doi: 10.1002/2015WR017408
Water professionals have been struggling with how to account for anthropogenic climate change (ACC) in current and future hydrologic design. Milly et al. (2008) asserted that “stationarity is dead”, meaning the idea that data is not changing over time (e.g. the mean, variance and autocorrelation of the data). This has also been asserted in ecology, natural resource management and many other fields due to the already-occurring impacts of climate change. However, infrastructure investments in ACC nor evidence of ACC occurring should be accepted as scientific evidence that stationarity is indeed dead, the authors argue. They provide a thoughtful overview of the importance of the topic and review commentary on the issue. They support the case already stated by Montanari and Koutsoyiannis (2014) that the way forward in dealing with ACC must “bridge the gap between physically based models without statistics and statistical models without physics”. They claim that a “suitable successor” to stationarity has yet to be found, and it is a major challenge for hydrologists and water resource engineers.
Federal Water Resources and Climate Change Workgroup Releases an update to its National Action Plan
The Federal Water Resources and Climate Change Workgroup has updated its National Action Plan. Titled “Looking Forward: Priorities for Managing Freshwater Resources in a Changing Climate,” the report discusses three areas of action (research, management, and outreach) and offers updated recommendations for each. Recommendations span data collection and monitoring networks to increased training and support for communities and resource managers. Learn more about the report and the specific ways that all federal agencies involved in water resource management are making efforts to incorporate climate change into their mission here: https://acwi.gov/climate_wkg/iwrcc/.
Dobrowski, S.Z., J. Abatzoglou, A.K. Swanson, J.A. Greenberg, A.R. Mynsberge, Z.A. Holden, M.K. Schwartz (2013) The climate velocity of the contiguous United States during the 20thcentury. Global Change Biology 19: 241-251
This portion of the AdaptWest site provides links to climatic water balance data for the continental United States (CONUS). The data are derived from the Parameter Regression of Independent Slopes Model (PRISM) data for the period 1900-2010, soils data from SSTATSGO, and atmospheric data from NLDAS-2 and NARR…. Using the water balance data climate change velocity for actual evapotranspiration, deficit, and minimum temperature is assessed over the CONUS during the 20th century (1916–2005)…. Climate change velocity describes the rate and direction which an organism would need to migrate to maintain an isocline of a given climate variable.
Potential for snow to supply human water demand in present and future
Mankin, J. S., Viviroli, D., Singh, D., Hoekstra, A. Y., & Diffenbaugh, N. S. (2015). The potential for snow to supply human water demand in the present and future. Environmental Research Letters, 10(11), 114016.
A new study identifies drainage basins in the Northern Hemisphere that are at risk of losing their snow-supplied water source in the upcoming century. The study quantified where changes to snowmelt runoff are likely to present the most pressing adaptation challenges, given sub-annual patterns of human water consumption and water availability from rainfall. The researchers used a multi-model ensemble of climate change projections. The study found that the snow-dependent basins of the Northern Hemisphere that are at risk of losing their water supply are currently populated by 2 billion people. These basins were estimated to be exposed to a 67% risk of decreased snow supply. Of these basins, the researchers identified 32 that were found to be the most sensitive to change. Included in this category were basins in northern and central California (where very productive agricultural land exists), and the Colorado River basin that serves most of the American West. The results from this study come with irreducible uncertainty, however, and can mainly be used to emphasize the importance of snow for fulfilling human water demand in many Northern Hemisphere basins.
Seasonal snowpack characteristics influence soil temperature and water content at multiple scales in interior western U.S. mountain ecosystems
Maurer, G. E., and D. R. Bowling (2014), Seasonal snowpack characteristics influence soil temperature and water content at multiple scales in interior western U.S. mountain ecosystems, Water Resour. Res., 50, doi:10.1002/2013WR014452
Effects of climate change on snowpack and fire potential in the western U.S.
Gergel, D.R., Nijssen, B., Abatzoglou, J.T. et al. 2017. Effects of climate change on snowpack and fire potential in the western USA. Climatic Change 141: 287. doi:10.1007/s10584-017-1899-y
Researchers evaluated the implications of ten twenty-first century climate scenarios for snow, soil moisture, and fuel moisture across the conterminous western U.S. using the Variable Infiltration Capacity (VIC) hydrology model. A decline in mountain snowpack, an advance in the timing of spring melt, and a reduction in snow season were projected for five mountain ranges in the region. For the southernmost range (the White Mountains), spring snow at most elevations is projected to disappear by the end of the twenty-first century. The accelerated depletion of mountain snowpack due to warming will likely lead to reduced summer soil moisture across mountain environments. Similarly, warmer and drier summers will likely lead to decreases of up to 25% in dead fuel moisture across all mountain ranges. Collective declines in spring mountain snowpack, summer soil moisture, and fuel moisture across western mountain ranges will increase fire potential in flammability-limited forested systems where fuels are not limiting. Projected changes in fire potential in predominately fuel-limited systems at lower elevations were more uncertain.
Five centuries of U.S. west coast drought
Wise, E. K. (2016), Five centuries of U.S. West Coast drought: Occurrence, spatial distribution, and associated atmospheric circulation patterns, Geophys. Res. Lett., 43, 4539–4546, doi:10.1002/2016GL068487.
The drought along the west coast of the U.S. that began in 2012 formed in relation to a high-pressure ridge linked to internal atmospheric variability. In this recently published study, University of North Carolina scientist Erika Wise examined this most recent drought (the occurrence, spatial patterns, and associated circulation features) through a paleoclimate context by linking atmospheric circulation to surface hydroclimate patterns. Spatial reconstructions of upper atmosphere pressure patterns and cool-season drought showed that drought along the U.S. west coast has occurred periodically since 1500 C.E. These droughts were also found to be associated with a strong ridge centered along the Pacific Northwest coast.
Local variability mediates vulnerability of trout populations to land use and climate change
Penaluna, B. E., Dunham, J. B., Railsback, S. F., Arismendi, I., Johnson, S. L., Bilby, R. E., ... & Skaugset, A. E. (2015). Local variability mediates vulnerability of trout populations to land use and climate change. PloS one, 10(8), e0135334.
Land use and climate change occur simultaneously around the globe. Fully understanding their separate and combined effects requires a mechanistic understanding at the local scale where their effects are ultimately realized. In this study, a group of researchers applied an individual-based model of fish population dynamics to evaluate the role of local stream variability in modifying responses of Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) to scenarios simulating identical changes in temperature and stream flows linked to forest harvest, climate change, and their combined effects over six decades. The study found that climate change most strongly influenced trout (earlier fry emergence, reductions in biomass of older trout, increased biomass of young-of-year), but these changes did not consistently translate into reductions in biomass over time. Forest harvest, in contrast, produced fewer and less consistent responses in trout. Earlier fry emergence driven by climate change was the most consistent simulated response, whereas survival, growth, and biomass were inconsistent. Overall the findings from this study indicate that a host of local processes can strongly influence how populations respond to broad scale effects of land use and climate change.
Climate change, hydrology and fish morphology
Michel, M.J., Chien, H., Beachum, C.E. et al. 2016. Climate change, hydrology, and fish morphology: predictions using phenotype-environment associations
Climatic Change, pp. 1-14. doi:10.1007/s10584-016-1856-1
In this recently published study, biologists use the relationship between genetic traits and specific species habitat to predict species ability to genetically adapt to future habitats under climate change. Specifically, the authors examined this method of evaluating climate change impact on biodiversity using the relationship between fish body shape and stream flow as a case study. The authors applied this phenotype-environment relationship (fish in high-flow habitats exhibit more streamlined body shapes than fish in low-flow habitats) to quantify changes in fish body shape under future streamflow conditions and predicting the success rate of fish species to be able to adapt to such future conditions. The authors show a variety of results, with some fish populations successfully altering their body shape at the rate that their habitat will change, while others were categorized as vulnerable species. The study concluded by emphasizing this method’s applicability to a wide range of taxa.
Linking the hydrologic impacts of atmospheric rivers to Rossby wave breaking on the US West Coast
Hu, H., Dominguez, F., Wang, Z., Lavers, D. A., Zhang, G., & Ralph, F. M. 2017. Linking Atmospheric River Hydrological Impacts on the US West Coast to Rossby Wave Breaking. Journal of Climate, DOI: http://dx.doi.org/10.1175/JCLI-D-16-0386.
Scientists from the University of Illinois and Scripps Institute of Oceanography recently published their study examining the connection between the landfalling of Atmospheric Rivers and types of Rossby wave breaking on the U.S. West Coast. Rossby waves in the atmosphere are wind currents associated with planetary rotation, that either rotate clockwise (anti-cyclonic) or counterclockwise (cyclonic) depending on the direction of flow. These two types of Rossby waves exhibit different angles of wave breaking when they come in contact with land, such as the U.S. West Coast. Through this study, the authors identified the main type or Rossby wave breaking associated with the Northwest coastline and the California coastline. They found that anticyclonic Rossby wave breaking is the dominant connection to extreme streamflows in the Northwest while cyclonic Rossby wave breaking was found to be responsible for extreme streamflows along the California coast.
Changes in distribution of rain frequency and intensity in response to global warming
A.G. Pendergrass & D. L. Hartmann. 2014. Two modes of change of the distribution of rain. Journal of Climate: 27, 8357-8371. doi: http://dx.doi.org/10.1175/JCLI-D-14-00182.1http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-14-00182.1
Two recent papers in the Journal of Climate examine changes in rainfall distribution associated with climate change. The first paper defines two modes of rainfall response to global warming and applies them to daily rainfall over ENSO phases in models and observations, demonstrating good fit. The second paper applies the perspective of energetics and finds that global warming will likely shift patterns of rainfall toward higher rain rates and overall increases in moisture and extreme events.
The Cold-Water Climate Shield: Preserving Salmonid Fishes through the 21st Century
Isaak, D. J., Young, M. K., Nagel, D. E., Horan, D. L. and Groce, M. C. (2015), The cold-water climate shield: delineating refugia for preserving salmonid fishes through the 21st century. Global Change Biology. doi: http://dx.doi.org/10.1111/gcb.12879
Researchers from the Rocky Mountain Research Stations in Montana and Idaho recently published a study in Global Change Biology titled: “The cold-water climate shield: delineating refugia for preserving salmonid fishes through the 21st century.” Researchers identified especially cold habitats capable of absorbing future climate change while still supporting native populations, highlight important salmonid refugia in the western U.S. Through coupling crowd-sourced biological datasets with high-resolution stream temperature scenarios, researchers delineated network refugia across >250,000 stream km in the Northern Rocky Mountains for two native salmonids—bull trout and cutthroat trout. This approach creates a framework to integrate data contributed by many individuals and resource agencies, and a process that strengthens the collaborative and social networks needed to preserve many cold-water fish populations through the 21st century.
How should flood risk assessments be done in a changing climate?
Schultz, C. (2014), Eos Trans. AGU, 95(35), 324; re: Rosner, A., R. M. Vogel, and P. H. Kirshen (2014), A risk-based approach to flood management decisions in a nonstationary world, Water Resour. Res., 50, 1928–1942, doi:10.1002/2013WR014561
Growing consensus on climate and land use change means that it is reasonable to assume, at the very least, that flood levels in a region may change. Then why, ask Rosner et al. in a new study, do the dominant risk assessment techniques used to decide whether to build new flood protection infrastructure nearly always start with an assumption of “no trend” in flood behavior?
Temporal patterns and regional variability in 555 years of conterminous U.S. streamflow
Ho, M., Lall, U., Sun, X. and Cook, E.R. In press. Multiscale temporal variability and regional patterns in 555 years of conterminous US streamflow. Water Resources Research, 53. DOI:10.1002/2016WR019632
Scientists from Columbia University reconstructed and characterized streamflow variability at a continental scale using a spatially and temporally complete 555-year-long paleoclimate record of summer droughts. They found decadal-scale variability in the late 1900s in the western U.S., while similar modes of temporal variability were rarely present before the 1950s. The twentieth century featured longer wet spells and shorter dry spells compared with the preceding 450 years, and streamflows in the Pacific Northwest and Northeast are negatively correlated with the central U.S.. These streamflow patterns highlight the potential to mitigate some drought impacts by balancing economic activities and insurance pools across these regions in major droughts.
Representing climate change stresses on groundwater using the GRACE satellite
Richey, A.S., Thomas B.F., Lo, M.-H., Reager J.T., Famiglietti J.S., Voss K., Swenson S., and Rodell M. 2015. Quantifying renewable groundwater stress with GRACE. Water Resources Research 51, pp. 5217-5238. doi: 10.1002/2015WR017349
The combined effects of population growth and climate change result in increasing stresses on global freshwater availability. Groundwater comprises about 30% of global freshwater, and much of the remaining freshwater is contained in glaciers and is thus inaccessible as a water source. As the incidence of drought globally increases, groundwater is being increasingly relied on as a more resilient source of water. However, climate change is simultaneously altering the spatial and temporal distribution of groundwater availability. Richey et al (2015) draws on data from the GRACE satellite to assess groundwater stress globally and to quantify the relationship between groundwater use and availability in 37 aquifer systems around the world. They use a metric called the Renewable Groundwater Stress ratio, which is the ratio of groundwater use to availability. The authors compare data from the GRACE satellite to nationally reported groundwater withdrawal statistics and classify aquifers using four stress regimes: overstressed, variable stress, human-dominated stress and unstressed. Although many aquifers experience severe stresses, land use changes determine the extent to which aquifers are able to adapt to stressed conditions. Data from the GRACE satellite, rather than nationally reported statistics, provide a better representation of the range of stressed conditions that may occur due to climate change and demographic growth.
Report for NPLCC Summarizes Hydrology-related Manager Information Needs
Woodward, Andrea, and Jenni, Karen, 2014, Resource manager information needs regarding hydrologic regime shifts for the North Pacific Landscape Conservation Cooperative: U.S. Geological Survey Open-File Report 2014-1178, 28 p., http://dx.doi.org/10.3133/ofr20141178
A new report details outcomes from a North Pacific Landscape Conservation Cooperative workshop held in January, 2014 that focused on changes in hydrologic regime on rivers, streams, and riparian corridors. The USGS helped to determine what information managers need in order to address the consequences of climate change on valued resources. [FullText] Contact: Andrea Woodward, 206-526-2534, firstname.lastname@example.org
A GoogleMap Tool for InterAgency Coordination of Annual Stream Temperature Monitoring Sites
It had been 2 years since the Rocky Mountain Research Station last updated the online GoogleMap Tool for tracking stream sites across North America where annual temperature monitoring was currently occurring. The objective of the tool is to provide people from all agencies with a simple way to see where annual stream temperature monitoring is happening so that data sharing is facilitated and redundancy is minimized as new monitoring sites are established. You can see the map showing the updated set of sites by visiting the link below. Clicking on the map icons provides contact information for the local data stewards and information about the stream site. You can also display and filter information pertaining to different site attributes and the information can be saved in various formats like KMZ files for display in Google Earth.
Tracking Interannual Streamflow Variability with Drought Indicies in the US Pacific Northwest
Abatzoglou, J.T.; R. Barbero; J.W. Wolf; & Z. A. Holden. 2014. Tracking Interannual Streamflow Variability with Drought Indices in the U.S. Pacific Northwest. J. Hydrometeor, 15, 1900–1912. doi: http://dx.doi.org/10.1175/JHM-D-13-0167.1
Drought indices are often used to monitor interannual variability in regional pattern of hydrology, but approaches vary widely. This study correlated various indices to water-year runoff for 21 unregulated drainage basins in the Pacific Northwest of the United States to identify those indices that explain the greatest amount of variability.
Stream temperature Variability: Why it matters to Salmon
The July issue of Science Findings (a USFS Pacific Northwest Research Station publication) is devoted to salmon, stream temperature variance, and how climate change and human activities can affect natural variability. A recent study indicates that the commonly used degree-day accumulation model is not sufficient to predict how organisms respond to stream temperature. Changes in how the degree days are delivered have the potential to alter the timing of life history transitions in Chinook salmon and other organisms
Characterization of post-fire streamflow response across western US watersheds
Saxe, S., Hogue, T. S., and Hay, L. 2016. Characterization of post-fire streamflow response across western US watersheds, Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-533, in review.
Researcher Samuel Saxe from the Colorado School of Mines collaborated with researchers from the United States Geologic Survey to examine the impact of wildfires on watershed flow regimes. The authors synthesized data on fire events, watershed characteristics, and streamflow in order to identify watersheds with at least ten years of pre- and post-fire daily streamflow records. These 82 watersheds were then categorized into nine regions and used to produce regression models analyzing total area burned. Findings from this study showed a significant increase in flow during the first two years following a wildfire, and then a decrease over time. Watersheds in eastern California, western Nevada and Oregon demonstrated a negative relative post-fire flow, while watersheds in other regions of the U.S. showed a positive mean relative flow. The authors concluded that the correlation between area burned and flow was limited, indicating that change in flow could be dominated by other watershed factors.
Climate change impact on the roles of temperature and precipitation in western U.S. snowpack variability
Scalzitti, J., Strong, C., & Kochanski, A. (2016). Climate change impact on the roles of temperature and precipitation in western U.S. snowpack variability. Geophys. Res. Lett. Geophysical Research Letters, 43(10), 5361-5369. doi:10.1002/2016gl068798
In this recently published study, atmospheric scientists from the University of Utah examined the impact of temperature and precipitation change on spring snowpack variability across the western United States. The authors conducted a 26-year historical dynamical downscaling simulation and a simulation of future climate change. They found that the negative correlation between spring snowpack and temperature weakens linearly with elevation. They also found that the correlation between spring snowpack and precipitation increases exponentially with elevation. The historical simulation showed that there is a range of threshold elevations (1580–2181 m) across six mountainous regions, above which precipitation is the main driver of snowpack variability and below which temperature is the main driver. Under a moderate end-of-century climate change scenario, these thresholds were seen to increase by 191 to 432 m.
The National Stream Internet Project: An Analytical Infrastructure for Data on Stream Networks
Accurate, high resolution information does not exist for consistent status and trend assessments of water quality and aquatic biotas throughout the >3,000,000 kilometers of rivers and streams in the U.S. Without that information, prioritization of limited resources for conservation and management proceeds inefficiently. In recent decades, however, massive amounts of water quality, biological surveys, and habitat condition data have been collected by state, federal, tribal, and private organizations. In many cases, high-quality information could be developed from those data if a nationally consistent analytical infrastructure for data on stream networks existed. The National Stream Internet (NSI) Project was funded by the Landscape Conservation Cooperative Network as a national initiative grant to develop that infrastructure. The project has three simple objectives: (1) develop and refine free statistical software for the analysis of data on stream networks, (2) ensure compatibility between the stream software and the National Hydrologic Dataset, and (3) conduct a workshop with researchers and aquatic program leaders to brainstorm about national priorities and the opportunities that big data and stream statistics now provide for developing better information about aquatic resources.
Seeing the landscape for the trees: Metrics to guide riparian shade management in river catchments
Johnson & Wilby. 2015. Seeing the landscape for the trees: Metrics to guide riparian shade management in river catchments. Water Resources Research DOI 10.1002/2014WR016802
The warming effect of solar radiation on rivers varies across space and time. Thus the benefits of shading through riparian restoration will also vary from site to site. These authors used a network of high-resolution temperature measurements from two upland rivers in the UK along with topographic shade modeling to assess how shade affects water temperature. Conditions under which shade is most effective at reducing water temperature and amount of shade needed to offset warming of 1 degree Celsius are discussed.
Using Air Temperature to Model Stream Warming
Caldwell, P., Segura, C., Gull, S., Sun, G., McNulty, S.G., Sandercock, M., Boggs J., James, M. 2015. Short-term stream water temperature observations permit rapid assessment of potential climate change impacts. Hydrological Processes 29, 2196-2211.
A new U.S. Forest Service Southern Research Station study demonstrates how long-term historic air temperature data can be used in conjunction with short-term stream temperature data to project future warming in streams. Peter Caldwell, a research hydrologist at the Coweeta Hydrologic Laboratory, led the study. Caldwell and his colleagues showed how only 18 months of stream temperature observations could be used to explain variability in stream temperature for up to 37 years. They used these findings to model historical stream temperatures at 61 sites in the Southeastern United States from 1961 to 2010, and then used these models to project future temperatures from 2011 through 2060. They found that stream temperatures had already increased during the historical period, and those streams located in the Appalachian ecoregion were predicted to be most vulnerable to climate change. These findings were seen as a significant breakthrough, as before it was very difficult to project long-term climate change impacts on stream temperature.
Understanding the hydroclimatic conditions that preceded the 2014 Oso Landslide
Henn B, Cao Q, Lettenmaier DP, Magirl CS, Mass C, Bower JB, St. Laurent M, Mao Y, Perica S (2015) Hydroclimatic Conditions Preceding the March 2014 Oso Landslide. J. Hydrometeor 16: 1243-1249.
A team of UW and UCLA researchers, along with USGS and NOAA scientists, have studied the hydroclimatic conditions that preceded the March 2014 Oso landslide, also called the SR 530 landslide by the State of Washington, in an effort to understand how and why it occurred. It was one of the deadliest landslides in U.S. history, resulting in 43 deaths and significant destruction of infrastructure. The authors examine regional weather information, precipitation records, and soil moisture leading up to the event. They found that there was anomalously high precipitation in the weeks leading up to the landslide, along with strong moisture transport to the Pacific Northwest. Soil moisture was also higher than usual. These combined factors likely contributed to the severity of the landslide.
More than $280,000 for Salmon Projects
State funding has been approved for work making the Nisqually River and Ohop Creek more hospitable to salmon. The Pierce Conservation District and the Nisqually Land Trust, leaders on the projects, are among organizations in 29 counties across Washington that will share $18 million in grants awarded to restore and conserve salmon habitat in the region. Some of the grant money will be used to remove Japanese knotweed in the Nisqually River basin. Reducing knotweed presence in the river basin will provide more places for Chinook salmon, a threatened species, to spawn, feed, rest, and hide from predators.
Hydrological effects of forest transpiration loss in bark beetle-impacted watersheds
Bearup, L.A., Maxwell, R.A., Clow, D.W., and McCray, J.E. 2014. Hydrological effects of forest transpiration loss in bark beetle-impacted watersheds, Nature Climate Change 4, 481-486. doi: http://www.dx.doi.org/10.1038/nclimate2198
The mountain pine beetle infestation of the Rocky Mountains has resulted in unprecedented tree death across North America. Researchers analyzed contributions to streamflow over time and space to investigate the potential for increased groundwater inputs resulting from hydrological change following the mountain pine beetle infestation. Results of this study in Rocky Mountain National Park show that on average, groundwater fractions remain higher after infestation even when including the assumption that interannual differences in snow water equivalent translate directly to less streamflow. Additionally, results indicated that forest transpiration decreased after trees infected with the mountain pine beetle died. Understanding the impacts of mountain pine beetle infestation on the hydrological cycle provides necessary understanding for water resource management in mountain pine beetle infested forests.
Measurements by school pupils paved way for key research findings on lakes and global warming
Gesa A. Weyhenmeyer, Murray Mackay, Jason D. Stockwell, Wim Thiery, Hans-Peter Grossart, Pétala B. Augusto-Silva, Helen M. Baulch, Elvira de Eyto, Josef Hejzlar, Külli Kangur, Georgiy Kirillin, Don C. Pierson, James A. Rusak, Steven Sadro, R. Iestyn Woolway. 2017. Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming. Scientific Reports, 7: 43890 DOI: 10.1038/srep43890
High school students from Sweden conducted a citizen science project and, in collaboration with Uppsala University, produced key results for understanding the effect of increased warming on lake ecologies. Measurements of heat flux were collected by 3,500 Swedish students by examining the temperature difference between surface water and overlying air. The students were able to identify whether the lake was a source or sink of greenhouse gases and found that, in fact, heat flux was found to be increasingly negative with further warming. That is, as the overlying air is increasing in temperature, the lake surface water seems to be staying substantially colder. This observed mechanism could serve as a reduction of greenhouse gas transfer into the atmosphere.
Flows of the Future—How Will Climate Change Affect Streamflows in the Pacific Northwest?
Grant, G., Safeeq, M., Staab, B., Lewis, S., Kramer, M., & Tague, C. (2016, July). Flows of the Future—How Will Climate Change Affect Streamflows in the Pacific Northwest? Science Findings, (187). Retrieved from http://www.fs.fed.us/pnw/sciencef/scifi187.pdf
Scientists at the Pacific Northwest Research have created streamflow sensitivity maps that indicate how major watersheds are expected to respond to climate change. The research discusses several ways in which climate change can impact streamflow including flow volumes and the role precipitation plays in maintaining adequate water levels. The maps are intended for use by land managers in both Washington and Oregon to adapt specific management plans.
Extent of the rain-snow transition zone in the western U.S. under historic and projected climate
Klos, P. Z., T. E. Link, and J. T. Abatzoglou (2014), Extent of the rain-snow transition zone in the western U.S. under historic and projected climate, Geophys. Res. Lett., 41, doi:10.1002/2014GL060500
This study investigates the extent of the rain-snow transition zone across the complex terrain of the western United States for both late 20th century climate and projected changes in climate by the mid-21st century. Observed and projected temperature and precipitation data at 4 km resolution were used with an empirical probabilistic precipitation phase model to estimate and map the likelihood of snow versus rain occurrence. This approach identifies areas most likely to undergo precipitation phase change over the next half century. At broad scales, these projections indicate an average 30% decrease in areal extent of winter wet-day temperatures conducive to snowfall over the western United States. At higher resolution scales, this approach identifies existing and potential experimental sites best suited for research investigating the mechanisms linking precipitation phase change to a broad array of processes, such as shifts in rain-on-snow flood risk, timing of water resource availability, and ecosystem dynamics.
Depletion and response of deep groundwater to climate-induced pumping variability
Russo, T.A. & Lall, U. 2017. Depletion and response of deep groundwater to climate-induced pumping variability Nature Geoscience 10, 105–108. doi:10.1038/ngeo2883
Widespread groundwater level declines have occurred in the U.S. over recent decades, even in regions not typically considered water stressed, such as areas of the Northwest. This loss of water storage reflects extraction rates that exceed natural recharge and capture. In this article the authors explore recent changes in the groundwater levels of deep aquifers from wells across the U.S., and their relation to indices of climate variability and annual precipitation. They found that groundwater level changes corresponded to selected global climate variations. Although climate-induced variations of deep aquifer natural recharge are thought to have multi-year time lags, they found that deep groundwater levels respond to climate over timescales of less than one year. In irrigated areas, the annual response to local precipitation in the deepest wells may reflect climate-induced pumping variability. Understanding how the human response to drought leads to deep groundwater changes is critical for managing the impacts of climate variability on the nation’s water resources.
Flood risk growing in the northern U.S., declining in the South
Slater, L. J., and G. Villarini (2016), Recent trends in U.S. flood risk, Geophys. Res. Lett., 43, doi:10.1002/2016GL071199.
University of Iowa scientists recently published a study mapping current flood threats across the United States. The study compared stream height data in 2,042 streams and rivers from 1985 to 2015 and categorized the results using National Weather Service flood level categories. Findings showed very apparent trends across the country. Northern regions generally exhibited a growing flood risk with increased groundwater volume, while the opposite was seen in most southern regions. The largest decline in stored water was seen in central California, Texas, and New Mexico.
Trends in snow cover and other variables at weather stations in the conterminous US
Knowles, N. (2015). Trends in Snow Cover and Related Quantities at Weather Stations in the Conterminous United States. Journal of Climate, 28(19), 7518-7528.
Noah Knowles from the USGS used three statistical analyses (trend tests, linear regression, and canonical correlation analysis) to study National Weather Service Cooperative Observer (COOP) changes to snow depth data from 1950-2010. Knowles showed that patterns toward later snow-cover onset in the western half of the conterminous United States and earlier snow-cover onset in the eastern half, combined with a widespread trend toward earlier final meltoff of snow cover produced shorter snow seasons in the eastern half of the United States and longer snow seasons in the Great Plains and southern Rockies. Additionally, the annual total number of days with snow cover exhibited a widespread decline. Knowles concluded that temperature is the dominant variable influencing snow cover during the warmer snow-season months, while the colder months are dominated by a combination of temperature and precipitation. A canonical correlation analysis indicated that most trends presented here took hold in the 1970s, consistent with the temporal pattern of global warming during the study period.
The interactive effects of climate change, riparian management, and a nonnative predator on stream-rearing salmon
Lawrence, David J., Ben Stewart-Koster, Julian D. Olden, Aaron S. Ruesch, Christian E. Torgersen, Joshua J. Lawler, Don P. Butcher, and Julia K. Crown. 2014. The interactive effects of climate change, riparian management, and a nonnative predator on stream-rearing salmon. Ecological Applications 24:895–912. http://dx.doi.org/10.1890/13-0753.1
Researchers found that riparian restoration could prevent the extirpation of chinook salmon from… altered stream(s) and could also restrict bass from occupying the upper (portions) of salmon-rearing habitat. The proposed methodology and model predictions are critical for prioritizing climate-change adaptation strategies before salmonids are exposed to both warmer water and greater predation risk by nonnative species.
New insights on global groundwater depletion from NASA satellite
Famiglietti, J.S. 2014. The global groundwater crisis. Nature Climate Change: 4, 945-948. doi:10.1038/nclimate2425 http://www.nature.com/nclimate/journal/v4/n11/full/nclimate2425.html
National Aeronautics and Space Administration (NASA) used a novel satellite-based mapping technique to determine changes in water volumes in seven major aquifers around the world. In all cases, the aquifers are being pumped and depleted faster than they can naturally recharge, with some on track to being fully depleted within decades. Vanishing groundwater will cause major declines in agricultural productivity and energy production, with the potential for skyrocketing food prices and profound economic and political ramifications. Groundwater declines may also cause significant political conflict. In the face of these threats, the author identified five key steps that warrant immediate international attention.
Linking hydroclimate to fish phenology and habitat use with ichthyographs
Flitcroft, R.L., Lewis, S.L., Arismendi, I., LovellFord, R., Santelmann, M.V., Safeeq, M. and Grant, G., 2016. Linking Hydroclimate to Fish Phenology and Habitat Use with Ichthyographs. PloS one, 11(12), p.e0168831.
The authors of this recent PLoS ONE paper used long-term datasets of daily flow, temperature, and fish counts from Winchester Dam in southern Oregon to understand links between the phenology of upstream migration and environmental regimes. The authors used a new technique that synthesized large amounts of data related to fish migration on the North Umpqua River into what they call an “ichthyograph.” Their ichthyographs show the general patterns in upstream migration for six fish species native to the Northwest – steelhead, sucker, chinook salmon, lamprey, cutthroat trout and coho salmon. Authors hope that the ichthyographs will help fisheries managers assess the impacts of climate change or human-related activity such as water control and diversion, floodplain stabilization and road construction.
The Olympic Mountains Experiment
Houze Jr, R.A., McMurdie, L.A., Petersen, W.A., Schwaller, M.R., Baccus, W., Lundquist, J., Mass, C., Nijssen, B., Rutledge, S.A., Hudak, D. and Tanelli, S. In press. The Olympic Mountains Experiment (OLYMPEX). Bulletin of the American Meteorological Society. DOI: http://dx.doi.org/10.1175/BAMS-D-16-0182.1
A team of scientists conducted a rigorous field campaign to study how precipitation in Pacific storms changes as it passes over coastal mountains. In this Olympic Mountains Experiment (OLYMPEX), researchers sought to validate physical and hydrologic information for the US/Japan Global Precipitation Measurement (GPM) satellite mission. The study involved several Doppler radars, surface stations, autonomous cameras, specialized research aircrafts, and specialized instruments that track winds and storm conditions. In addition to aiding in satellite validation, the OLYMPEX dataset will serve the general need to advance the fundamental understanding of precipitation processes.
Snowpack in Western Mountains to Shrink Over Time
Klos, P.Z., T.E. Link, & J.T. Abatzoglou (2014). Extent of the rain-snow transition zone in the western U.S. under historic and projected climate, Geophys. Res. Lett., 41, 4560–4568, doi:10.1002/2014GL060500.
Mote, P.W., A.F. Hamlet, M.P. Clark, & D.P. Lettenmaier (2005) Declining mountain snowpack in western North America, Bull. of the Amer. Meteorol. Soc.,86, 39–49. doi: 10.1175/BAMS-86-1-39
The winter wonderland of snow-capped mountains in the western United States is becoming less snowy. Indeed, a fundamental shift in wintertime precipitation in the mountains and highlands of the American West is on the way, researchers suggest. Across the region, many communities — among them towns and cities in the wet Pacific Northwest — rely on water stored in mountain snowpack to meet their needs during the dry summer months. But the snowfall that builds this critical snowpack increasingly will turn to rain as our climate warms, according to University of Idaho researchers, including CIRC’s John Abatzoglou. This “snow-dominated” area could contract by as much as 30 percent by the middle of this century if worldwide carbon emissions continue growing rapidly.
What’s more, the season of “exclusive snowfall” (when temperatures are rarely warm enough for rain) in western mountain ranges — typically November to March — is projected to shorten by almost two months. The hardest-hit regions are expected to be the Northern Rockies, North Cascades and Blue Mountains, where winter temperatures will no longer be conducive to exclusive snowfall.
Not only will snow-dominated areas disappear, the extent of rain-dominated areas will expand. Nearly two-thirds of the Columbia Plateau region is projected to experience only rain where in the past there was a mix of snow and rain.
So far, nearly half of the western U.S. has remained cold enough in winter to experience precipitation almost exclusively as snow. But these particular mountain regions are especially sensitive to climate change-induced winter warming. That’s because their mid-elevations and relatively mild winters keep them marginally close to the freezing point where snow becomes rain. By contrast higher elevation and colder mountain regions — such as the Sierra Nevada, Central and Southern Rockies — are projected to retain some areas of exclusive snowfall.
These findings provide a spatially detailed interpretation and extension of observed and simulated trends at point locations, previously published by CIRC researchers Phil Mote and Dennis Lettenmaier, who found that since the mid-20th century, the mountains with mild winters had lost the greatest fraction of their snow. Detailed maps and data depicting the probability of rain versus snow in the western US both historically and in the future are publicly available here.
Relative effects of climate change and wildfires on stream temperatures
Holsinger, Lisa; Keane, Robert E.; Isaak, Daniel J.; Eby, Lisa; Young, Michael K. 2014. Climatic Change. Relative effects of climate change and wildfires on stream temperatures: A simulation modeling approach in a Rocky Mountain watershed. 2014. Climatic Change. 124: 191-206. Online: http://www.treesearch.fs.fed.us/pubs/46508.
The authors created a model using landscape fire and vegetation data and an equation that predicted daily stream temperatures to explore how climate change and its impacts on fire might affect stream temperature across a partially forested, mountainous landscape in the western U.S. The model provides insights into the roles that wildfire and management actions such as fuel reduction and fire suppression could play in mitigating stream thermal responses to climate change.
Snowpack regimes of the Western United States
Trujillo, E., and N. P. Molotch (2014), Snowpack regimes of the Western United States, Water Resour. Res., 50, 5611–5623, doi:10.1002/2013WR014753
Snow accumulation and melt patterns play a significant role in the water, energy, carbon, and nutrient cycles in the montane environments of the Western United States. Recent studies have illustrated that changes in the snow/rainfall apportionments and snow accumulation and melt patterns may occur as a consequence of changes in climate in the region. In order to understand how these changes may affect the snow regimes of the region, the current characteristics of the snow accumulation and melt patterns must be identified. Here researchers characterize the snow water equivalent (SWE) curve formed by the daily SWE values at 766 snow pillow stations in the Western United States, focusing on several metrics of the yearly SWE curves and the relationships between the different metrics. The metrics are the initial snow accumulation and snow disappearance dates, the peak snow accumulation and date of peak, the length of the snow accumulation season, the length of the snowmelt season, and the snow accumulation and snowmelt slopes. Three snow regimes emerge from these results: a maritime, an intermountain, and a continental regime. The maritime regime is characterized by higher maximum snow accumulations reaching 300 cm and shorter accumulation periods of less than 220 days. Conversely, the continental regime is characterized by lower maximum accumulations below 200 cm and longer accumulation periods reaching over 260 days. The intermountain regime lies in between. The regions that show the characteristics of the maritime regime include the Cascade Mountains, the Klamath Mountains, and the Sierra Nevada Mountains. The intermountain regime includes the Eastern Cascades slopes and foothills, the Blue Mountains, Northern and Central basins and ranges, the Columbia Mountains/Northern Rockies, the Idaho Batholith, and the Canadian Rockies. Lastly, the continental regime includes the Middle and Southern Rockies, and the Wasatch and Uinta Mountains. The implications of snow regime classification are discussed in the context of possible changes in accumulation and melt patterns associated with regional warming.
Fragmented patterns of flood change across the United States
Archfield, S. A., R. M. Hirsch, A. Viglione, and G. Blöschl (2016), Fragmented patterns of flood change across the United States, Geophys. Res. Lett., 43, doi:10.1002/2016GL070590.
A recent study from the United States Geologic Survey used 70 years of mean daily streamflow data to examine changes in flood frequency, magnitude, duration, and volume across various physiographic and climatic regions of the United States. The researchers categorized flood events into four groups: minimal change, increasing frequency, decreasing frequency, and increasing in all aforementioned flood properties. The study found that flood behavior exhibited weak geographic cohesion, revealing a complex and fragmented pattern of flood change across the U.S.
Impacts of Climatic Variation on Trout: A Global Synthesis and Path Forward
Kovach, R. P., Muhlfeld, C. C., Al-Chokhachy, R., Dunham, J. B., Letcher, B. H., & Kershner, J. L. (2015). Impacts of climatic variation on trout: a global synthesis and path forward. Reviews in Fish Biology and Fisheries, 1–17. doi: 10.1007/s11160-015-9414-x
Due to the lack of studies quantifying climate-induced impacts on trout, Kovach et al. (2016) synthesized existing research to review the current understanding of how trout ecology may be affected by climate variation, specifically due to temperature and streamflow changes. Rigorous meta-analysis was difficult to accomplish because of the limited number of current studies, however a consistent positive relationship was found between summer streamflow and trout demography and growth. Temperature was a less influential factor on trout ecology, though a negative relationship was found between summer and fall temperatures and trout demography. The authors concluded that more research must be conducted on climate-induced changes to trout ecology, as trout are a group of fish with global economic, ecological, and cultural importance.
Forest Service Puts Brakes on Controversial Groundwater Directive
The head of the U.S. Forest Service said that the agency's Proposed Directive on Groundwater Resource Management has been put on hold to enable more engagement with Western states. That's positive news for Western Governors, who expressed concern to Agriculture Secretary Tom Vilsack about the proposed directive shortly after its release last July. The governors noted then in a letter that "Western states are the exclusive authority for allocating, administering, protecting and developing groundwater resources, and they are responsible for water supply planning within their boundaries."
Uncertainties in modeling the snow hydrology of the Fraser River Basin in British Columbia
Islam, S. U. and Déry, S. J. 2016, in review. Evaluating uncertainties in modelling the snow hydrology of the Fraser River Basin, British Columbia, Canada, Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-469
Scientists from the University of Northern British Columbia recently published their findings on the projection uncertainties of snow hydrology in the Fraser River Basin. The authors used the Variable Infiltration Capacity (VIC) model to examine several climate datasets. At various stages of the dataset implementation, the researchers assessed uncertainties. These stages include driving datasets, optimization of model parameters, and model calibration during cool and warm phases of the Pacific Decadal Oscillation. The authors found that predictions of temperature and precipitation varied across datasets and model simulations, with the most variation in mountainous regions. Overall, the researchers found that the Pacific Climate Impacts Consortium dataset and the University of Washington dataset had reliable snow hydrology results across the Fraser River Basin, while other datasets had issues with precipitation and/or air temperature. Uncertainties were found in both the datasets and the model, revealing the need for improved methods and collection of observational data.
Scientists say that climate change is intensifying drought in California
Williams AP, Seager R, Abatzoglou JT, Cook BI, Smerdon JE, Cook ER. Contribution of anthropogenic warming to California drought during 2012-2014. Geophys Res Lett. 42, 10.1002/2015GL064924.
The debate on the causes of the California drought continues. A research team concluded that global warming has intensified the drought in California by 15 to 20 percent and warned that future dry spells are likely to be as bad or worse than the current one. The team shows how climate change was responsible for between 8 to 27 percent of the soil moisture deficit that occurred in California between 2012 to 2014. However, Columbia University climate scientist A. Park Williams noted in an interview that the method used in the study did not take into account accelerated global warming trends since the 1970s. Taking this into account, climate change is most likely responsible for about 15 to 20% of the moisture deficit. The remainder of the moisture deficit can be explained by interannual variability in precipitation. The study also found that California drought conditions were record breaking in 2014, but most likely not in 2012 and 2013, except in the southern Central Valley and highly populated coastal areas.
California snowpack won't recover until 2019
Margulis, S. A., G. Cortés, M. Girotto, L. S. Huning, D. Li, and M. Durand (2016), Characterizing the extreme 2015 snowpack deficit in the Sierra Nevada (USA) and the implications for drought recovery, Geophys. Res. Lett., 43, doi:10.1002/2016GL068520
A recent paper in Geophysical Research Letters supports an argument that state hydrologists have been making for months: It will take several years to recover from the recent four-year water shortage. The continually low snowpack in the Sierra Nevada created a large water deficit that may not be recovered until 2019. In April 2015, California’s water content hit 5% of its annual average, the lowest it has been in 500 years. Forecasters thought that a strong 2015 El Nino would alleviate some of the “water stress” the state was under, but winter ended up having close to normal conditions. On March 30, the water content held by the state’s snowpack was 87% of normal – a vast improvement from 5% the year prior, but still below average.
Western Water Report and Basin-Specific Manager Tool Released by the DOI
Reclamation (Bureau of Reclamation). 2016. SECURE Water Act Section 9503(c) – Reclamation Climate Change and Water. Prepared for United States Congress. Denver, CO: Bureau of Reclamation, Policy and Administration.
Under the requirements of the SECURE Water Act of 2009, the Department of the Interior’s Bureau of Reclamation has released a report characterizing climate-change induced projected effects for river basins in the Western United States. The Bureau of Reclamation, the largest provider of both water and hydroelectric power for the nation, worked with state and local partners to categorize the risks specific to each basin and produce a publically available online tool that visualizes these basin-specific impacts as well as potential adaptation options. Concerning the Northwest United States, the report discusses potential risks to the Columbia and Missouri River Basins, as well as the Klamath and Truckee River Basins. The report described the Columbia and Missouri basins as potentially exhibiting a precipitation shift from snow to rain. This shift indicates more runoff in the wintertime than the summertime due to less snow melt. Consequences of this climate-change induced impact will be reduced irrigation supply and hydroelectric power, and increased wintertime flood control challenges. The Klamath and Truckee basins were projected to exhibit increased stress on fisheries, salmon habitat loss, increased water and hydropower demand, and higher vulnerability to invasive species infestation. For more information, or to visit the online tool, go to: http://www.usbr.gov/climate/secure/
Largest Trust Water Donation in State History
The Cascade Water Alliance has agreed not to divert a total of 684,571 acre-feet of water from the White river that it was entitled to take. The agreement, which supports the state Department of Ecology’s Trust Water Rights Program, is part of a larger agreement dating back to 2010. The permanent donation, as well as a temporary donation of 154,751 acre-feet, completes an agreement made five years ago between the state and the alliance. The trust water donation helps maintain water flow levels in the region, a key indicator for fish habitat quality. Water flows for struggling fish in the White River will be protected for decades because of the permanent donation.
Predicting Climate Change Impacts on Aquatic Ecosystems across the Pacific Northwest
In case you missed it last December, USGS ecologist, Clint Muhlfeld’s, webinar about climate impacts to NW trout and salmon is now available online.
Avalanche fatalities during atmospheric river events in the western US
Hatchett, B.J., Burak, S., Rutz, J.J., Oakley, N.S., Bair, E.H. and Kaplan, M.L., 2017. Avalanche Fatalities During Atmospheric River Events in the Western United States. Journal of Hydrometeorology. DOI: http://dx.doi.org/10.1175/JHM-D-16-0219.1
A new study led by the Desert Research Institute examined the relationship between atmospheric river occurrence and avalanche fatalities in the western United States from 1998 to 2014. They found atmospheric river conditions to be apparent during or preceding 105 avalanches that resulted in a total of 123 fatalities. Geographical distribution of these fatalities show the highest percentage coinciding with coastal snow avalanche climates, followed by intermountain and then continental snow avalanche climates. Findings from this study show that the intensity of inland water vapor transport could help identify periods of heightened avalanche hazard.
Commentary on Heightened Risk of Drought due to Climate Change
Mann, M.E. and P.H. Gleick 2015. Climate change and California drought in the 21st century. PNAS 112, 13, 3858-3859. doi: 10.1073/pnas.1503667112
In this commentary piece, Pacific Institute Director Peter Gleick and Pennsylvania State University Meteorologist Michael Mann discuss the state of current literature on drought and climate science. They discuss a new study published in PNAS by Diffenbaugh et al., which shows accumulating evidence that climate change is influencing the frequency, magnitude and duration of drought in California. An increasing number of dry years along with warm years raise the risk of drought, despite the lack of a strong trend in precipitation. These results point to the significance of warming temperatures to changing the availability of water and increasing drought intensity. It is important to note, however, as the authors do, that this is not uncontested. A number of recent studies (some of which focused on a lack of trend in precipitation) concluded that a link between ocean temperatures and drought could not yet be established. Part of the debate, however, has occurred because there are many ways in which drought can be defined. A drought can be meteorological, hydrological, agricultural, and/or socioeconomic. Other parts of the debate stem from attribution. Some studies argue that low levels of precipitation cannot be tied to climate change, while others argue that while this may be true, the low levels of precipitation are caused by an unusually strong ‘atmospheric ridge’ in the Western United States, which was most likely stronger due to climate change.
Snowmelt rate dictates streamflow
Barnhart, T. B., Molotch, N. P., Livneh, B., Harpold, A. A., Knowles, J. F., & Schneider, D. (2016). Snowmelt Rate Dictates Streamflow. Geophys. Res. Lett. Geophysical Research Letters. doi:10.1002/2016gl069690
A recent paper in Geophysical Research Letters presents a possible mechanism linking snowmelt rate to streamflow generation. The results of the study indicate that there is a strong correlation between snowmelt rate and baseflow efficiency, which supports the idea that greater snowmelt rates increases subsurface flow. As temperatures continue to increase this may lead to earlier, slower snowmelt, decreasing streamflow production.
Earlier snowmelt reduces carbon storage
Winchell, T. S., D. M. Barnard, R. K. Monson, S. P. Burns, and N. P. Molotch (2016), Earlier snowmelt reduces atmospheric carbon uptake in midlatitude subalpine forests, Geophys. Res. Lett., 43, 8160–8168, doi:10.1002/2016GL069769.
A team of researchers from the University of Colorado examined the relationship between carbon uptake and snow ablation periods in this new study. The authors used 15 years of eddy covariance data in Colorado and found that the colder ablation-period air temperatures during years with earlier snowmelt led to reduced carbon uptake. From this observed phenomenon, the authors then projected net carbon uptake for an average mid-century ablation period using a multilinear regression. Findings from this projection show a possible 45% reduction in carbon uptake due to earlier snowmelt caused by increased global temperatures.
River sediment: Once maligned, now much loved
Scientists are reconsidering the role that river sediments play in maintaining wetlands as sea levels continue to rise. Human activity has destroyed or badly damaged about two-thirds of the world's wetlands — but researchers have started to recognize the silt, sand and gravel carried downstream can help rebuild those ecosystems. This represents a shift in the prevalent view among wetland scientists from that sediments are harmful. Sediment restoration projects are now underway across the globe, but scientists are still looking to improve their cost-effectiveness. In Louisiana officials are trying to mimic annual flood cycles to rebuild Louisiana's coastal wetlands. Dutch engineers are using a massive, man-made peninsula of sand to encourage beaches to build up naturally along the coast. And China's Xiaolangdi Dam on the Yellow River uses specially built portals to flush sediment from behind the dam up to two weeks each year.
Next Steps for Managing Freshwater Resources in a Changing Climate
Next Steps for Managing Freshwater Resources in a Changing Climate summarizes recommendations for implementing the National Action Plan: Priorities for Managing Freshwater Resources in a Changing Climate. The report was developed by the Water Resources Adaptation to Climate Change Workgroup that supports the Advisory Committee on Water Information - a national federal advisory committee made up of representatives of a diverse set of stakeholders and federal agencies. The Workgroup organized five subgroups based on the major recommendation topics in the National Action Plan: data and information for decision-making; vulnerability assessment; water use efficiency and conservation; integrated water resource management; and capacity building in training and outreach. The report is the result of discussions that took place at a two-day meeting of the Workgroup members in February 2014.
Saying goodbye to glaciers
Moon, T. 2017. Saying goodbye to glaciers. Science, 356 (6338): 580 DOI: 10.1126/science.aam9625
In this Perspectives piece from the journal Science, Twila Moon, a glacier expert at the University of Colorado Boulder, writes about today’s massive decline in the world’s glaciers. She describes how glacial loss causes sea level rise, which will displace millions of people within the lifetime of many of today’s children. From providing freshwater to communities to impacting global weather and climate systems, glaciers play an important role on earth. Moon writes about how the focus of her glacial research has changed over the years to integrate the impacts of climate change, and she calls for continued diligence from the scientific community.
Climate change darkening Seattle’s water forecast
This summer’s drought is changing the long-term outlook for Seattle’s water forecast. Seattle Public Utilities (SPU) models of future water utilities show that Seattle is looking at a reduced ‘firm yield’ of 30% on average through 2050. Firm yield describes the amount of water that can be reliably delivered. Prior to this summer, SPU officials thought that there would be no major water-supply problems before 2060. But now things look different. Director of SPU, Ray Hoffman, stated, “’This year, as tough as it is, is a real revelation for what the future might look like.’” SPU is in the process of thinking through possible adaptation options that might mitigate the severity of future droughts. Alex Chen, SPU’s director of water planning, is exploring various ideas for maximizing performance, including an increase of water storage in the Cedar and Tolt reservoirs or reusage of precipitation falling on Seattle. Chen even mentioned desalinization.
Scientists collaborated with Google to map long-term global surface water occurrence
Jean-François Pekel, Andrew Cottam, Noel Gorelick, Alan S. Belward. High-resolution mapping of global surface water and its long-term changes. Nature, 2016; DOI: 10.1038/nature20584
Scientists from the European Commission Joint Research Centre partnered with Google to produce the Global Surface Water Explorer, an interactive map of surface water change from 1984-2015. The tool was created by processing over three million Landsat satellite images and quantifying the data into a 30-meter resolution map. Findings from this dataset were published in Nature and include measured and evident impacts of climate change and climate oscillations on surface water occurrence. Among these findings, the authors emphasize that all continental regions except Oceania show a net increase in permanent surface water, and that areas of water loss are more geographically concentrated around mainly the Middle East and Central Asia. The Global Surface Water Explorer is now free and open to the public.
Flaws Detected in Models that Predict Future Changes in Stream Temperature
Ivan Arismendi, Mohammad Safeeq, Jason B Dunham and Sherri L Johnson, Can air temperature be used to project influences of climate change on stream temperature? Environmental Research Letters,vol 9, 084015, http://stacks.iop.org/1748-9326/9/i=8/a=084015
Researchers found that regression-based statistical models that predict stream temperatures based on more widely available air temperature data did not accurately predict long-term changes in stream temperatures, likely due to additional influential variables, such as groundwater contributions or riparian shading. This model evaluation shows that other alternatives are needed.
Contrasting distribution patterns of invasive and naturalized non-native species in a semi-arid montane ecosystem
Anderson, K. M., Naylor, B. J., Endress, B. A., & Parks, C. G. (2015). Contrasting distribution patterns of invasive and naturalized non-native species along environmental gradients in a semi-arid montane ecosystem. Applied Vegetation Science, 18(4), 683-693.
A new study examines differences in distribution patterns of invasive and naturalized non-native species along various environmental gradients in a semi-arid montane ecosystem. The researchers surveyed non-native plant species along three mountain roads to assess the extent of invasion success in relation to distance from the roadside, as well as along the native habitat matrix to assess invasion success in relation to elevation gradients. The study found that invasive species have similar patterns of habitat associations and spread from roadsides to interior vegetation zones, whereas naturalized species partition environmental gradients within the semi-arid montane ecosystem. The study further suggests that annual and invasive species groups occupy lower elevations and perennial and naturalized species groups have invaded further up the mountains roads and into the native vegetation. The study concluded that functional groupings potentially explain contrasting distribution patterns of non-native species. Findings from this research can be used to inform management strategies for non-native species, particularly in how such strategies must be modified to accommodate the difference in species behavior along environmental gradients.
Great Basin Landscape Conservation Cooperative’s 2017 Public Forum Feedback Summary now available
The Great Basin Landscape Conservation Cooperative (GBLCC) recently published a report summarizing feedback obtained in an online Public Forum that the GBLCC hosted from Jan. 23 – Feb. 8, 2017. During that time more than 230 people visited the interactive website to learn about recent GBLCC efforts and provide feedback on ideas for future work. The report highlights ideas and comments provided by Public Forum visitors on several topics, including: prioritization of the Great Basin LCC’s key objectives; ideas for new Steering Committee members; rangeland fire prevention and management; improving the resiliency of Great Basin forests and woodlands; opportunities for partnering with Great Basin tribes; and future webinar topics and information sharing efforts.
An eco-regional approach to landscape conservation in the NW Great Basin
A new project called the Northwest Basin and Range (NWBR) Synthesis is a collaborative effort to bring organizations and communities in central/eastern Oregon, northwest Nevada, and northeast California toward a common understanding of a plan for conservation. Led by staff from the Great Basin Landscape Conservation Cooperative (GBLCC), the NWBR is focused on building a conservation blueprint that authentically incorporates the human dimension within the Great Basin. Learn more about these efforts from their website and/or read the latest Northwest Climate Magazine to find an article highlighting the work of the GBLCC and this project.
Climate Change and Land Management Impact Rangeland Condition and Sage-Grouse Habitat in SE Oregon:
Megan K. Creutzburg, Emilie B. Henderson and David R. Conklin (2015) Climate change and land management impact rangeland condition and sage-grouse habitat in southeastern Oregon. AIMS Environmental Science 2(2): 203-236. http://bit.ly/1yQS9JF
Megan Creutzburg and Emilie Henderson of Oregon State University, and David Conklin of Common Futures LLC have a new publication in AIMS Environmental Science for their Northwest Climate Science Center-funded project, “Climate change and land management impact rangeland condition and sage-grouse habitat in southeastern Oregon.” Creutzburg and her collaborators modeled projected shifts in vegetation distributions and potential sage-grouse habitat across 23.5 million acres in southeastern Oregon. The team evaluated four climate scenarios and three management scenarios, including no management, current management, and a sage-grouse habitat restoration scenario. This work provides resource managers with information about potential impacts of climate change, disturbances, and management activities on rangeland species such as the greater sage-grouse.
Science framework for conservation and restoration of the sagebrush biome
Chambers, J.C., Beck, J.L., Bradford, J.B., Bybee, J., Campbell, S., Carlson, J., Christiansen, T.J., Clause, K.J., Collins, G., Crist, M.R. and Dinkins, J.B., 2017. Science framework for conservation and restoration of the sagebrush biome: Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions. General Technical Report. 213 pp.
The U.S. Forest Service developed this Science Framework, which is designed to link the Department of the Interior’s Integrated Rangeland Fire Management Strategy with long-term strategic conservation actions in the sagebrush biome. A geospatial process is presented that overlays information on ecosystem resilience and resistance, species habitats, and predominant threats. Also, a resilience and resistance habitat matrix is provided to help decision-makers determine appropriate management strategies. It is anticipated that the Science Framework will be widely used to: (1) inform emerging strategies to conserve sagebrush ecosystems, sagebrush dependent species, and human uses of the sagebrush system, and (2) assist managers in prioritizing and planning on-the-ground restoration and mitigation actions across the sagebrush biome.
BLM Embarks on Major Juniper Removal in Idaho to Save Sage Grouse
The BLM has announced plans to cut, chop, and burn native juniper trees across 1.5 millions acres of southwest Idaho in hopes of combatting a major threat to the greater sage grouse. The juniper trees provide habitat for sage grouse predators such as hawks, ravens, and crows, and these predators frequently overtake bunch grasses and sagebrush necessary for sage grouse survival. Treatment of the juniper trees is projected to take place over several years and will focus on trees located within 6 miles of the ~70 occupied sage grouse breeding grounds. Most treatments of the trees will involve mulching the trees on site or lopping and scattering them.
Development of Soil Moisture Drought Index to Characterize Droughts
Sohrabi, M., Ryu, J., Abatzoglou, J., and Tracy, J. (2015). "Development of Soil Moisture Drought Index to Characterize Droughts." J. Hydrol. Eng., 10.1061/(ASCE)HE.1943-5584.0001213, 04015025.
Scientists from the University of Idaho recently published a report on a newly developed drought index called the “soil moisture drought index (SODI)”. Developed in order to characterize droughts, the index is based on the amount of water required to attain soil moisture at field capacity. SODI captures variations of precipitation, temperature, and soil moisture over time. Three widely used drought indices, including the standardized precipitation index (SPI), the standardized precipitation evapotranspiration index (SPEI), and the self-calibrated palmer drought index (sc-PDSI) were compared to the SODI along with local hydrological variables such as streamflow, reservoir storage, and groundwater level. Results indicated that SODI reacts more to changes in precipitation and temperature than SPI and SPEI, and overall outperformed the existing indices due to its ability to detect and quantify the extended severe droughts associated with climate variability and change. The authors concluded that SODI will add momentum to build a case toward the use of soil moisture information for drought analysis in a changing environment.
Annual Changes in Bluebunch Wheatgrass Biomass and Nutrients Related to Climate and Wildfire
Peek, James M. 2014. Annual Changes in Bluebunch Wheatgrass Biomass and Nutrients Related to Climate and Wildfire. Northwest Science 88(2): 129-139
Current year's growth (biomass) and nutrient levels of bluebunch wheatgrass (Pseudoroegneria spicata), a highly palatable bunchgrass in western North America, were evaluated over 20-year and 10-year periods, respectively. Three study sites representing a range of variation in conditions were located on south-facing slopes. Annual biomass ranged from 5.6 to 109.0 gm m-2 on individual sites with means for all sites of 42.7 gm m-2 (range 17.5–73.3 gm m-2), with April and May precipitation best predicting the variation. Variation was highest on the site lowest in elevation and highest in biomass. A fire in August 2000 that burned all study sites suppressed biomass for the following two years, aided by lower than average precipitation. The highest elevation site had higher mean values of Cu, Mg, N, K, P, S, and Zn than the two lower sites, but the greatest range of values occurred on one of the two lower sites for Ca, Fe, K, Mg, N, P, and S. Combinations of temperature and precipitation predicted Ca, K, N, P, and Zn values, while Cu and Fe were predicted with total monthly precipitation, and Mg and S were predicted with mean monthly temperature. Values of Cu, Fe, K, N, P, S, and Zn were higher than expected for one to two years following the 2000 fire, while Ca and Mg did not show any responses to the fire. Predictions for biomass and nutrient content apply to the range of conditions, temperatures and precipitation observed over the study period. The predictions may be useful in assessing responses to changes in climate, and are helpful in explaining variation in herbivore populations relative to changes in forage quality and quantity.
Desert shrub responses to experimental modification of precipitation seasonality and soil depth: relationship to the two-layer hypothesis and ecohydrological niche
Germino, M. J., Reinhardt, K. 2014. Desert shrub responses to experimental modification of precipitation seasonality and soil depth: relationship to the two-layer hypothesis and ecohydrological niche. Journal of Ecology 102: 989–997. doi: 10.1111/1365-2745.12266
Sagebrush was found to be more responsive to the seasonal timing of precipitation than to total annual precipitation. Factors that enhanced deep-water storage (deeper soils plus more winter precipitation) led to increases in Artemisia tridentate… and the contribution of shallow water to growth on these plots was consistent with the resource-pool hypothesis. However, shallow-soil water also had negative effects on sagebrush, suggesting an ecohydrological trade-off not considered in these or related theories. The interaction between precipitation timing and soil depth indicates that increased winter precipitation could lead to a mosaic of increases and decreases in A. tridentata across landscapes having variable soil depth.
Sagebrush ecosystems and Greater Sage-Grouse habitat
Using resistance and resilience concepts to reduce impacts of invasive annual grasses and altered fire regimes on the sagebrush ecosystem and Greater Sage-Grouse: A strategic multi-scale approach. Chambers, Jeanne C.; Pyke, David A.; Maestas, Jeremy D.; Pellant, Mike; Boyd, Chad S.; Campbell, Steven B.; Espinosa, Shawn; Havlina, Douglas W.; Mayer, Kenneth E.; Wuenschel, Amarina. 2014. Gen. Tech. Rep. RMRS-GTR-326. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 73 p. Online: http://www.fs.fed.us/rm/pubs/rmrs_gtr326.html
This report provides a strategic approach for conservation of sagebrush ecosystems and Greater Sage-Grouse (sage-grouse) that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on factors that influence (1) sagebrush ecosystem resilience to disturbance and resistance to invasive annual grasses and (2) distribution, relative abundance, and persistence of sage-grouse populations to develop management strategies at both landscape and site scales. A sage-grouse habitat matrix links relative resilience and resistance of sagebrush ecosystems with sage-grouse habitat requirements for landscape cover of sagebrush to help decision makers assess risks and determine appropriate management strategies at landscape scales.
Global warming will likely decrease the extent of temperate drylands
Daniel R. Schlaepfer et al. Climate change reduces extent of temperate drylands and intensifies drought in deep soils. Nature Communications, 2017; 8: 14196 DOI: 10.1038/ncomms14196
A team of international scientists collaborated to study the specific impact of climate change on drylands in the mid-latitudes (temperate region). The authors analyzed projections of changes in soil moisture and ecological droughts which have major influences on vegetation productivity in temperate drylands. Findings from this study suggest that temperate drylands may decrease by 30% by the end of the century and be converted into subtropical drylands. Additionally, the authors found that deep soil layers are projected to become increasingly dry during the growing season.
Range-wide connectivity of priority areas for Greater Sage-Grouse: Implications for long-term conservation from graph theory
Crist, M.R., Knick, S.T. and Hanser, S.E., 2017. Range-wide connectivity of priority areas for Greater Sage-Grouse: Implications for long-term conservation from graph theory. The Condor.
Researcher Michele Crist and colleagues from the United States Geological Survey recently published a new method for prioritizing areas of sagebrush habitat that support Greater Sage-Grouse populations. Called graph theory, the statistical technique is a way of quantifying the network role of each area by assigning nodes to priority areas and revealing the overall interconnectedness of the areas to other sagebrush habitats. The authors emphasized the need to maintain corridors between habitats in order to sustain genetic variability and biodiversity of the sagebrush ecosystem.
Recent Desiccation of Western Great Basin Saline Lakes
Moore, J.N. 2016. Recent desiccation of Western Great Basin Saline Lakes: Lessons from Lake Abert, Oregon, U.S.A. Science of the Total Environment 554, 142–154. http://dx.doi.org/10.1016/j.scitotenv.2016.02.161
Johnnie Moore, a geoscientist from the University of Montana, recently published results from a study examining the drivers of saline lake desiccation in the Western Great Basin. Lake Abert in southern Oregon has exhibited large scale desiccation in recent years, and was nearly dry in 2014 and 2015. This desiccation has resulted in the decline of brine shrimp and brine fly populations, consequently eliminating shorebird habitat. Using Lake Abert as a case study, Moore compiled Landsat images to construct a 65-year-long time series of the lake’s changes in volume and salinity. From this time series, Moore was able to quantify a “natural” hydrologic budget for the watershed and compare this to the current conditions of the saline lake. Natural conditions were defined to include every current input and output except for upstream human withdrawal. Moore found that, under natural conditions and even during the last two years of major drought, Lake Abert’s volume and salinity would be within normal range and the current environment would still be habitable for brine shrimp and fly populations. Findings from this study conclude that withdrawal of water for direct human use has drastically exacerbated the imbalance between natural runoff and evaporation during periods of drought. Moore emphasizes the need for an “environmental water budget” to offset this imbalance and restore the critical habitat for migratory shorebirds.
Genetic recapture identifies long-distance breeding dispersal in Greater Sage-Grouse
Todd B. Cross, David E. Naugle, John C. Carlson, and Michael K. Schwartz. 2017. Genetic recapture identifies long-distance breeding dispersal in Greater Sage-Grouse (Centrocercus urophasianus). The Condor 119:1, 155-166
Dispersal can strongly influence the demographic and evolutionary trajectory of populations. Yet, for many species, little is known about dispersal, despite its importance to conservation. This study investigated dispersal patterns among spring breeding congregations of the Greater Sage-Grouse (Centrocercus urophasianus), a species of conservation concern that ranges across 11 western U.S. states and 2 Canadian provinces. To do this, the team examined a microsatellite DNA dataset of 3,244 Greater Sage-Grouse sampled from 763 leks throughout Idaho, Montana, North Dakota, and South Dakota, USA, across 7 years. They recaptured ∼2% of individuals, documenting 41 instances of breeding dispersal, with 7 dispersal events of >50 km, including 1 of 194 km. They saw 39 recaptures on the same lek up to 5 yr apart, supporting the paradigm of philopatry in lekking species. They found no sex differences in breeding dispersal distances or in the tendency to disperse. Importantly, they did document movements within and among state-delineated priority areas of conservation importance, further supporting the need to identify movement corridors among these reserves. These results can be used to better inform the assumptions of count-based population models and the dispersal thresholds used to model population connectivity and potential range shifts related to climate change.
Synthesis on the fire ecology of the Greater and Gunnison Sage-Grouse
Innes, Robin J. 2016. Centrocercus minimus, C. urophasianus, sage-grouse. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/animals/bird/cent/all.html
U.S. Forest Service researcher, Robin Innes, recently released a synthesis of the fire effects information and relevant ecology of Greater and Gunnison sage-grouse in North America. Using scientific literature available as of 2016, Innes cited more than 300 publications. Innes found that greater sage-grouse occur in 56% of their historical range (pre-1800) and Gunnison sage-grouse occur in more than 10% of their historical range. Additionally, Innes found that while fire removes sagebrush plants that provide essential thermal and security cover and food year-round, it also creates openings useful as lek sites. Lastly, Innes reported that sage-grouse generally avoid nesting in young (<20 years old) burns, and burned sagebrush communities may not provide adequate winter cover for decades following fire.
2016 Annual Great Basin Landscape Conservation Cooperative (GBLCC) Highlights Report now available
The GBLCC recently released its annual report for 2016. Highlights include being a primary source of science for the Integrated Rangeland Fire Management Strategy; playing an integral role in developing the Rangeland Fire Science Plan; helping develop an online science information portal for managers tackling rangeland research across the Great Basin; investing over $1 million in new research projects and a new traditional knowledge initiative; co-hosting the 2016 Great Basin Consortium Conference, attended by 500 people; undertaking the Northwest Basin and Range Synthesis Project to identify shared priorities across a common landscape; supporting Great Basin tribes; and hosting their most popular webinar series to date.
Wildfire, climate, and invasive grass interactions negatively impact an indicator species by reshaping sagebrush ecosystems
Coates, P.S., Ricca, M.A., Prochazka, B.G., Brooks, M.L., Doherty, K.E., Kroger, T., Blomberg, E.J., Hagen, C.A., and Casazza, M.L. 2016. Wildfire, climate, and invasive grass interactions negatively impact an indicator species by reshaping sagebrush ecosystems. Proceedings of the National Academy of Sciences, 113(45): 12745-12750. DOI: 10.1073/pnas.1606898113
The sagebrush habitat of the Great Basin is currently threatened by a disturbance cycle of wildfire and annual invasive grass. A team of scientists from the United States Geologic Survey, U.S. Fish and Wildlife, University of Maine, and Oregon State University examined the impact of this disturbance cycle on the sage-grouse population, an indicator species of sagebrush ecosystems. The authors examined three decades of sage-grouse population counts, wildfire, and climate data and found that the cumulative loss of sagebrush from this cycle has been a driving influence for the decline in sage-grouse populations over the last 30 years. This study provides a quantifiable link between fire regimes and indicator species decline.
Persistence of greater sage-grouse in agricultural landscapes
Shirk, A.J., Schroeder, M.A., Robb, L.A. and Cushman, S.A., 2017. Persistence of greater sage‐grouse in agricultural landscapes. The Journal of Wildlife Management. DOI: 10.1002/jwmg.21268
A team of researchers used species distribution modeling to quantify environmental variables constraining a threatened sage-grouse population inhabiting an agricultural landscape in Washington. Fields planted to perennial vegetation as part of the Conservation Reserve Program (CRP) were important in providing year-round habitat for sage-grouse, but only when intermixed with native sagebrush-steppe vegetation. Without the CRP, researchers estimated 66% of sage-grouse habitat in the study area would become unsuitable. This study demonstrates how conservation programs such as CRP may be used as a management tool to reduce the risk of extirpation in agricultural areas, and to facilitate species range shifts in response to climatic changes in the sagebrush biome.
Climate change impacts on rangelands and sage-grouse habitat in southeastern Oregon
Creutzburg MK, Henderson EB, Conklin DR (2015). Climate change and land management impact rangeland condition and sage-grouse habitat in southeastern Oregon. AIMS Env Sci 2 (2): 203-236. doi: 10.3934/environsci.2015.2.203.
A new study integrates a number of different modeling efforts to project vegetation dynamics and sage-grouse habitat across 23.5 million acres in southeastern Oregon. The sage-grouse was once widespread but has recently declined to 56% of its original numbers due to declining habitat quality. The species was considered for inclusion as an endangered species but was excluded due to the existence of higher priority species. To understand future climate impacts on the sage-grouse, four climate scenarios were evaluated, along with three management scenarios: no management, current management and sage-grouse habitat restoration. Climate change scenarios projected an expansion of moist shrub steppe and decrease of dry shrub steppe, but varied in projections of the extent of xeric shrub steppe, which is the environment unfavorable for sage-grouse. The authors found that wildfires increased by 26% over the course of the 21st century as a result of the expansion of exotic grasses (and likely due to warming temperatures as well). Early in the 2000s, the average area burned in wildfires was around 200,000 acres, and by the end of the century, this increased to over 1.5 million acres. The increase in wildfires has complicated impacts on habitat, as it can control juniper expansion, but also remove shrubs that are crucial for nesting and brooding sage-grouse habitat. In sum, the authors found that rangeland conditions are expected to decline, and that current management options are not sufficient to counteract the projected impacts of climate change in the eastern Oregon rangelands.
Drought and Ecological Site Interaction on Plant Composition of a Semi-Arid Rangeland
Scasta, J. D., and B. S. Rector. 2014. Drought and Ecological Site Interaction on Plant Composition of a Semi-Arid Rangeland. Arid Land Research and Management 28:197-215
Fluctuating climatic patterns are increasing the frequency and severity of drought, a concern for native plant communities on grazed semi-arid rangelands. Vegetation successional models have focused on the impact of management and have failed to quantify the effects of extreme drought. From 2001 to 2011, plant community composition was sampled on ecological sites in a semi-arid rangeland managed with conservative grazing and frequent fire since 1937. Ordination and classification were used to assess the interactive effects of ecological site and extreme drought on plant species composition, holding all other external drivers constant. Deeper soil clay loam sites had 4x greater beta diversity than shallower and rockier low stony hill sites, an indication of greater species turnover and instability in response to extreme drought. Cumulative effects of drought years explained similarity between sites and species composition. Response to extreme drought varied by species; no response (Bouteloua curtipendula), decreased (Nassella leucotricha), and increased (Bouteloua rigidiseta and Eriochloa sericea). Annual C3 plant responses were explained by short-term drought and perennial C3 and C4 plant responses were explained by long-term drought. Clay loam sites had maximum species richness and diversity values during neutral periods with quadratic declines associated with climatic extremes (dry or wet) compared to the more xeric sites which had minimum species richness and diversity during neutral periods with quadratic increases during climatic extremes. The interaction between site and drought, holding all other external drivers constant, can enhance our understanding of plant community dynamics and secondary plant succession of degraded semi-arid rangelands.
Environmental Characteristics of Spring Systems
The Desert Research Institute recently released a new report reviewing the importance of springs in the Great Basin and Mojave Desert. Funded by the Great Basin LCC, the report examined 2,256 springs, measuring physical and chemical characteristics such as size, water chemistry, vegetative cover and substrate composition. The report found that approximately 83% of the springs displayed evidence of anthropogenic impact. The most common impacts included diversion, livestock use, recreation, and dredging. The report concludes by emphasizing the importance of managing and restoring these spring systems in order to improve ecological health of these rare desert environments.
Effects of climate change on net primary production of US rangelands
Reeves, M.C.; Moreno, A.L.; Bagne, K.E.; & Running, S.W. Estimating climate change effects on net primary production of rangelands in the United States. 2014. Climatic Change. Online: http://www.readcube.com/articles/10.1007/s10584-014-1235-8 DOI 10.1007/s10584-014-1235-8
Modeling and experimental results suggest that net primary productivity of grasslands of the interior west of the US will likely increase under future climate scenarios. Increases will not likely be uniform across the region, as grasslands dominated by warm season species responded most to temperature while cool season dominated regions responded more strongly to CO2 enrichment.
How will increases in rainfall intensity affect semiarid ecosystems?
Siteur, K., M. B. Eppinga, D. Karssenberg, M. Baudena, M. F. P. Bierkens, and M. Rietkerk (2014), How will increases in rainfall intensity affect semiarid ecosystems?, Water Resour. Res., 50, 5980–6001, doi:10.1002/2013WR014955
Model studies suggest that semiarid ecosystems with patterned vegetation can respond in a nonlinear way to climate change. This means that gradual changes can result in a rapid transition to a desertified state. Previous model studies focused on the response of patterned semiarid ecosystems to changes in mean annual rainfall. The intensity of rain events, however, is projected to change as well in the coming decades. In this paper, we study the effect of changes in rainfall intensity on the functioning of patterned semiarid ecosystems with a spatially explicit model that captures rainwater partitioning and runoff-runon processes with simple event-based process descriptions. Analytical and numerical analyses of the model revealed that rainfall intensity is a key parameter in explaining patterning of vegetation in semiarid ecosystems as low mean rainfall intensities do not allow for vegetation patterning to occur. Surprisingly, we found that, for a constant annual rainfall rate, both an increase and a decrease in mean rainfall intensity can trigger desertification. An increase negatively affects productivity as a greater fraction of the rainwater is lost as runoff. This can result in a shift to a bare desert state only if the mean rainfall intensity exceeds the infiltration capacity of bare soil. On the other hand, a decrease in mean rainfall intensity leads to an increased fraction of rainwater infiltrating in bare soils, remaining unavailable to plants. Our findings suggest that considering rainfall intensity as a variable may help in assessing the proximity to regime shifts in patterned semiarid ecosystems and that monitoring losses of resource through runoff and bare soil infiltration could be used to determine ecosystem resilience.
Do invasive alien plants benefit more from global environmental change than native plants?
Liu, Y., Oduor, A. M. O., Zhang, Z., Manea, A., Tooth, I. M., Leishman, M. R., Xu, X. and van Kleunen, M. 2017. Do invasive alien plants benefit more from global environmental change than native plants?. Glob Change Biol. doi:10.1111/gcb.13579
A recently published study compared the effects of climate change on non-native and native plants. Authored by an international team of scientists, the article used previous studies to compile a database of 74 non-native plant species and 117 native plant species in response to changes in mean levels of precipitation, temperature, atmospheric CO2 concentration and nitrogen deposition. Findings from the study showed that non-native species outperformed native species in every factor of climate change measured except for increased drought (decreased precipitation). These results indicated an increase in spread of non-native plants with future climate change.
Join the Great Basin Landscape Conservation Co-operative (GBLCC)’s Public Forum
The GBLCC recently launched a public forum to help shape the landscape-scale conservation work happening in the Great Basin. The forum is accessible here, and will remain open through February 6, 2017. The Public Forum is a short-term, interactive website where visitors can learn about the Great Basin LCC’s recent efforts and provide input on future work, including:
Future webinar topics and other opportunities for information sharing
Rangeland fire prevention, management and restoration
Expanding resistance and resilience work to forests and woodlands
Working with tribal partners
Suggestions for new Steering Committee members
The GBLCC is hoping to receive input from as many people as possible and would appreciate your help spreading the word. Have questions? Email: email@example.com.
Implications of Drought for Dryland Ecosystems
Hoover, D., Duniway, L., & Belnap, M. 2015. Pulse-drought atop press-drought: Unexpected plant responses and implications for dryland ecosystems. Oecologia, 179(4), 1211-1221.
In this study, USGS scientist David Hoover and colleagues performed a 4-year study researching the effects of drought on plant functional types in order to understand how changes to precipitation could impact ecosystems. The authors examined four dominant, native plant functional types (C3 grasses, C4 grasses, C3 shrubs, and C4 shrubs) across a 4500 km^2 region of the Colorado Plateau. Over the 4-year study, a press-drought (long-term, chronic drought) was experimentally induced and a pulse-drought (short-term, intense drought) naturally occurred, giving the study a chance to examine the additive effect of both types of drought on an ecosystem. The authors found that C3 grasses were the most sensitive functional group to drought and C3 shrubs were the most resistant. The occurrence of both press- and pulse-droughts caused higher-than-expected mortality of C3 grasses. In addition, the study examined the interaction between soils and drought, however found that soil variety played no interaction with drought treatments, a result contrary to the authors’ prediction.
Great Basin 2015-2016 Factsheet Series compilation now available online
Great Basin Fire Science Exchange has just released the 2015-2016 Great Basin Factsheet Series compilation. The factsheets were developed by with support from the Great Basin LCC, the Joint Fire Science Program, the Great Basin Research and Management Partnership, and the Sagebrush Treatment Evaluation Project. The compilation includes 14 factsheets on topics ranging from invasive annual grasses to grazing management to seeding and transplanting techniques.
Could rising CO2 levels help plants withstand drought?
Lem, P. (2016, June 7). Could rising CO2 levels help plants withstand drought? Greenwire. Retrieved from http://www.eenews.net/climatewire/stories/1060038395/search?keyword=Could rising CO2 levels help plants withstand drought?
Global drying may not be as extensive as some models predict, according to a recent study. Carbon dioxide helps plants become hardier against drought, and the effects of drying could be counteracted by plants using less water. While the plants’ water source is expected to decrease as warmer global climates cause more arid conditions in many areas, rising atmospheric CO2 could also allow plants to close their pores more often and preserve more water. Water saved by plants potentially means more water available for human and animal consumption. "As a result of this slight, but important increased availability of water in the soil, future droughts may be less frequent and less intense than many past studies have predicted," according to a statement from USGS.
The effects of precipitation and soil type on three invasive annual grasses in the western United States
Bansal, S., J. J. James, and R. L. Sheley. 2014. The effects of precipitation and soil type on three invasive annual grasses in the western United States. Journal of Arid Environments 104:38-42
Multiple species of annual grasses are invading sagebrush-steppe communities throughout the western United States. Most research has focused on dominant species such as Bromus tectorum (cheatgrass), yet other, less studied annual grasses such as Taeniatherum caput-medusae (medusahead) and Ventenata dubia (ventenata) are spreading rapidly. Future precipitation regimes are expected to have less frequent but more intense rain events, which may affect soil moisture availability and favor these ‘newer’ invasives over cheatgrass. We conducted a full factorial, growth chamber study examining the effects of two watering regimes (small/frequent, large/infrequent rain pulses) across nine soil types on the growth of cheatgrass, medusahead and ventenata. We tested a hypothesis that medusahead or ventenata would have greater growth than cheatgrass with larger/infrequent rain events. The two watering regimes had relatively strong effects on soil water content, but generally did not impact plant growth. In contrast, variation in soil properties such as clay content, pH and soil N correlated with a two- to four-fold change in plant growth. The three invasive grass species generally respond similarly to changes in precipitation regimes and to edaphic factors. Nevertheless, medusahead had 30–40% overall greater root growth compared to the other species and a 15% increase in root growth in response to the large/infrequent watering treatment. Our findings reveal that 1) greater biomass allocation to roots and 2) greater responsiveness of root growth to differing precipitation regimes of medusahead may favor its ecological success over other invasive annuals under future climate scenarios.
Climatic Controls of Aboveground Net Primary Production in Semi-Arid Grasslands along a Latitudinal Gradient Portend Low Sensitivity to Warming
Mowll, W., D. Blumenthal, K. Cherwin, A. Smith, A. Symstad, L. Vermeire, S. Collins, M. Smith, and A. Knapp. 2015. Climatic controls of aboveground net primary production in semi-arid grasslands along a latitudinal gradient portend low sensitivity to warming. Oecologia 177: 959-969. http://dx.doi.org/ 10.1007/s00442-015-3232-7
Although climate models forecast warmer temperatures with a high degree of certainty, precipitation is the primary driver of aboveground net primary production (ANPP) in most grasslands. Conversely, variations in temperature seldom are related to patterns of ANPP. Thus forecasting responses to warming is a challenge, and raises the question: how sensitive will grassland ANPP be to warming? Researchers evaluated climate and multi-year ANPP data (67 years) from eight western US grasslands arrayed along mean annual temperature (MAT; ~7–14 °C) and mean annual precipitation (MAP; ~250–500 mm) gradients. The researchers used regression and analysis of covariance to assess relationships between ANPP and temperature, as well as precipitation (annual and growing season) to evaluate temperature sensitivity of ANPP. Regression models indicated that variation in growing season temperature was negatively related to total and graminoid ANPP, but precipitation was a stronger predictor than temperature. Growing season temperature was also a significant parameter in more complex models, but again precipitation was consistently a stronger predictor of ANPP. Surprisingly, neither annual nor growing season SPEI were as strongly related to ANPP as precipitation. The researchers conclude that forecasted warming likely will affect ANPP in these grasslands, but that predicting temperature effects from natural climatic gradients is difficult. This is because, unlike precipitation, warming effects can be positive or negative and moderated by shifts in the C3/C4 ratios of plant communities.
How Projections for Drier Terrestrial Areas Vary Between Climate Models
Scheff, J. and D.M.W. Frierson. 2015. Terrestrial aridity and Its Response to Greenhouse Warming across CMIP5 Climate Models. Journal of Climate, 28. DOI: 10.1175/JCLI-D-14-00480.1
The degree of aridity of a terrestrial climate is typically evaluated by using the relative magnitudes of precipitation (P) and potential evapotranspiration (PET). This study uses an aridity index of P/PET and looks at how this index varies in 16 different global climate models from CMIP5. The authors find that the index agrees between climate models in most of Eurasia and North Africa, but disagree dramatically in large areas of North America, Sub-Saharan Africa and South Asia. The same areas can be represented as semiarid-to-arid or quite humid, depending on the climate model. This is in contrast to the climate adage “wet areas get wetter, dry areas get drier”.
Climate Change and Land Management in Central Oregon
Creutzburg MK, Halofsky JE, Halofsky JS, Christopher TA (2015) Climate Change and Land Management in the Rangelands of Central Oregon. Environmental Management 55: 43-55. doi: 10.1007/s00267-014-0362-3.
A new study examines potential climate change impacts on the condition of rangelands in central Oregon and evaluates several management strategies. For three different scenarios of climate change, the authors projected large shifts in vegetation types throughout the 21st century. Toward the end of the 21st century, they found declines in sagebrush steppe and in salt desert shrub. They found large increases in extreme fire years, which are projected to result in large and rapid shifts in vegetation types. Increases in exotic grasses and decreases in juniper encroachment are projected to occur. They found climate-driven shifts are projected to increase the complexity of rangeland management. Their method allows for future testing of different management strategies for dealing with the effects of climate change on rangelands.
Natural Regeneration Processes in Big Sagebrush
Schlaepfer, Daniel R., William K. Lauenroth, and John B. Bradford. 2014. Natural Regeneration Processes in Big Sagebrush (Artemisia tridentata). Rangeland Ecology and Management 67(4): 344-357
Potential impacts of climate change on big sagebrush regeneration could include that temperature increases may not have a large direct influence on regeneration due to the broad temperature optimum for regeneration, whereas indirect effects could include selection for populations with less stringent seed dormancy. Drier conditions will have direct negative effects on germination and seedling survival and could also lead to lighter seeds, which lowers germination success further. The short seed dispersal distance of big sagebrush may limit its tracking of suitable climate; whereas, the low competitive ability of big sagebrush seedlings may limit successful competition with species that track climate. An improved understanding of the ecology of big sagebrush regeneration should benefit resource management activities and increase the ability of land managers to anticipate global change impacts.
Increased precipitation variability decreases grass productivity and increases shrub productivity
Gherardi, L. A., & Sala, O. E. (2015). Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity. Ecology letters.
The impacts of projected variation in precipitation on functional diversity have received limited attention. Two scientists from Arizona State University examined the impact of increased levels of precipitation on the functional diversity of grass populations using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually, resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance.
Sagebrush and piñon-juniper ecosystems: Field guide for treatment
Miller, Richard F.; Chambers, Jeanne C.; Pellant, Mike. A field guide for selecting the most appropriate treatment in sagebrush and piñon-juniper ecosystems in the Great Basin: Evaluating resilience to disturbance and resistance to invasive annual grasses, and predicting vegetation response. 2014. Gen. Tech. Rep. RMRS-GTR-322. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 66 p. Online: http://www.fs.fed.us/rm/pubs/rmrs_gtr322.html.
This field guide identifies seven primary components that largely determine resilience to disturbance, as well as resistance to invasive grasses and plant succession following treatment of areas of concern: (1) characteristics of the ecological site, (2) current vegetation prior to treatment, (3) disturbance history, (4) type, timing, and severity of the treatment, (5) post-treatment weather, (6) post-treatment management, especially grazing, and (7) monitoring and adaptive management. A series of key questions and a set of tools are provided to assess these primary components. This assessment is designed to allow field personnel to (1) evaluate resilience to disturbance and resistance to invasive annual grass for an area of concern, (2) predict the potential successional pathways, and (3) then select the most appropriate treatment, including the need for seeding.
Climate warming alters fuels across elevational gradients in Great Basin bristlecone pine-dominated sky island forests
Gray, C.A. and Jenkins, M.J., 2017. Climate warming alters fuels across elevational gradients in Great Basin bristlecone pine-dominated sky island forests. Forest Ecology and Management, 392, pp.125-136. DOI: https://doi.org/10.1016/j.foreco.2017.03.004
Scientists from Utah State University examined the effects of climate-induced changes to fuel loading, fire hazard and risk on changes in fire behavior and severity in Great Basin bristlecone pine communities. Using Forest Inventory Analysis plot variables, researchers collected data in field transects on six mountains in the western U.S. Their results suggest that fine woody fuels decreased with elevation, and surface and canopy fuels at different elevations changed with increases in elevation. Authors note that these results, combined with lower canopy base height and foliar moisture and increasing temperatures due to climate change, increases fire potential at the Great Basin bristlecone pine treeline, threatening the oldest individuals of this iconic species.
Climate Change and Land Management in the Rangelands of Central Oregon
Creutzburg, M.K., Halofsky, J.E., Halofsky, J.S., Christopher, T.A. 2015. Climate change and land management in the rangelands of central Oregon. Environmental Management, 55(1), 43-55. doi: http://dx.doi.org/ 10.1007/s00267-014-0362-3
Climate change, along with exotic species, disturbances, and land use change, will likely have major impacts on sagebrush steppe ecosystems in the western U.S. over the next century. To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the interacting impacts of climate change, disturbances and land management on vegetation condition. Using a climate-informed state-and-transition model, researchers evaluated the potential impacts of climate change on rangeland condition in central Oregon and the effectiveness of multiple management strategies. Under three scenarios of climate change, researchers projected shifts in potential vegetation types over the 21st century, with declining sagebrush steppe and expanding salt desert shrub likely by the end of the century. Overall, climate-related shifts dominated future vegetation patterns, making management for improved rangeland condition more difficult. This approach allows researchers and managers to examine long-term trends and uncertainty in rangeland vegetation condition and test the effectiveness of alternative management actions under projected climate change.
Climate, CO2, and the history of North American grasses since the last glacial maximum
J. M. Cotton, T.E. Cerling, K.A. Hoppe, T.M. Mosier, C.J. Still. 2016. Climate, CO2, and the history of North American grasses since the Last Glacial Maximum. Science Advances, Vol. 2, no. 3, e1501346. DOI: 10.1126/sciadv.1501346
A new study published in Science Advances evaluated the climatic factors that influenced the compositional change in North American Grasses from the Last Glacial Maximum to present. Specifically, the authors examined the massive expansion of C4 grasses during the late Neogene era. The study first determined the “isotopic landscape” of C3/C4 grasses during the Last Glacial Maximum, mid-Holocene, and present using stable isotope composition found in mammoth and bison tissue. The study then used three statistical tests (classification and regression trees) to determine the climatic variables most influential for C4 grass expansion, which they found to be precipitation and temperature during growing season. The authors then compared their “isotopic landscapes” to climate data from the Last Glacial Maximum to the present and discovered that C4 grass expansion continued through the Great Plains during a time of increased atmospheric CO2 concentrations. The authors were able to conclude that precipitation, rather than temperature, during growing season was a critical factor in C4 grass expansion.
Northwest Hops Threatened by Drought
According to a recent NOAA article, hops yield may decline in the next century, disrupting future beer production. Nearly all hops grown in the United States are grown in the Northwest, primarily in the Yakima Valley of eastern Washington. The Yakima Valley is an arid basin that relies on winter precipitation stored as snowpack in the Cascade Mountains as its freshwater supply. The valley experienced declines in certain hops varieties from last year's extreme drought conditions. Many growers were able to adjust their techniques for the 2015 season, however adaptation could become more difficult as such extreme conditions become more frequent. The article points out that the Yakima Valley may be particularly vulnerable because its water resource will decline as snowpack lessens over the next century.
LANDFIRE has developed tailored materials to support macro reviews of the Intermountain Basin Big Sagebrush Shrubland
The LANDFIRE team, a national consortium of organizations and agencies, recently mapped the Biophysical Setting (BpS) of the Inter-mountain Basin Big Sagebrush Shrubland. The map consists of nearly 52 million acres and captures 12 unique models known as variants. The macro-review will be used to determine whether the model variants capture the actual ecological variation that exists across the range of the Inter-Mountains Basins Big Sagebrush Shrubland. Comments from the reviews will be assessed by the LANDFIRE team and considered for incorporation into the BpS model. Provide a review here.
The Department of the Interior releases online tool to protect “sagebrush sea” from wildfire
The Department of the Interior has released a new online tool designed to help land managers make sagebrush habitat more resilient to wildfires. The online tool, developed by the Bureau of Land Management and U.S. Geological Survey, gives federal, state and local officials access to a collection of geographic information system data, including extensive landscape-scale information. The data can be used to create printable maps to help select areas for preventative actions that will reduce the potential for future fires in sagebrush habitat. The online tool is one product from years of work by federal, state and local leaders to save the greater sage grouse, which depend on the sagebrush ecosystem to provide cover from predators and shelter to raise their chicks. Unfortunately, sagebrush burns easily and takes years to recover. Wildfires in recent years have scorched millions of acres of sagebrush across the West.
Grazing as a potential fuel management tool in shrub steppe communities
Davies Kirk W., Gearhart Amanda, Boyd Chad S., Bates Jon D. 2017. Fall and spring grazing influence fire ignitability and initial spread in shrub steppe communities. International Journal of Wildland Fire 26, 485-490. https://doi.org/10.1071/WF17065#sthash.0myeqeYl.dpuf
Authors of this paper investigated the effects of fall grazing, spring grazing and not grazing on fuel characteristics, fire ignition and initial spread during the wildfire season at five shrub steppe sites in Oregon. Both grazing treatments decreased fine fuel biomass, cover and height, and increased fuel moisture, thereby decreasing ignition and initial spread compared with the ungrazed treatment. However, effects differed between fall and spring grazing. The probability of initial spread was 6-fold greater in the fall-grazed compared with the spring-grazed treatment in August. This suggests that spring grazing may have a greater effect on fires than fall grazing, likely because fall grazing does not influence the current year’s plant growth. Grazing either the fall or spring before the wildfire season reduces the probability of fire propagation and, thus, grazing is potentially an effective fuel management tool.
Biodiversity/Species and Ecosystem Response
Influences of Climate Forcing on Freshwater and Forest Biota in the PNW
Black, B. A., Dunham, J. B., Blundon, B. W., Brim-Box, J. and Tepley, A. J. (2015), Long-term growth-increment chronologies reveal diverse influences of climate forcing on freshwater and forest biota in the Pacific Northwest. Global Change Biology, 21: 594–604. doi: http://dx.doi.org/10.1111/gcb.12756
Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Researchers developed a network of 8 growth-increment width chronologies for freshwater mussel species in the PNW, and integrated them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge. Mussel growth was also indirectly related to tree radial growth. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change.
Global variation in thermal tolerances and vulnerability of endotherms to climate change
Khaliq, Imran, Christian Hof, Roland Prinzinger, Katrin Böhning-Gaese, and Markus Pfenninger. 2014. Global variation in thermal tolerances and vulnerability of endotherms to climate change. Proceedings of the Royal Society B 281: 20141097
The relationships among species' physiological capacities and the geographical variation of ambient climate are of key importance to understanding the distribution of life on the Earth…. This research finds the expected relationship between thermal tolerance and ambient climatic variability in birds, but not in mammals—a contrast possibly resulting from different adaptation strategies to ambient climate via behaviour, morphology or physiology. Researchers show that currently most of the species are experiencing ambient temperatures well within their tolerance limits and that in the future many species may be able to tolerate projected temperature increases across significant proportions of their distributions. However, the findings also underline the high vulnerability of tropical regions to changes in temperature and other threats of anthropogenic global changes. This study demonstrates that a better understanding of the interplay among species' physiology and the geography of climate change will advance assessments of species' vulnerability to climate change.
Amphibians in the climate vise: loss and restoration of resilience of montane wetland ecosystems in the western US
Maureen E Ryan, Wendy J Palen, Michael J Adams, and Regina M Rochefort 2014. Amphibians in the climate vise: loss and restoration of resilience of montane wetland ecosystems in the western US. Frontiers in Ecology and the Environment 12: 232–240. http://dx.doi.org/10.1890/130145
Amphibians in the West’s high-mountain areas find themselves in a vise, caught between climate-induced habitat loss and predation from introduced fish. This North Pacific LCC-backed project developed a list of tools that could be of use to land managers working with montane wetlands including a hydrologic model and remote-sensing techniques.
Soil Nutrients may Limit Ability of Plants to Slow Climate Change:
William R. Wieder, Cory C. Cleveland, W. Kolby Smith, Katherine Todd-Brown. Future productivity and carbon storage limited by terrestrial nutrient availability. Nature Geoscience, 2015; DOI: http://dx.doi.org/10.1038/ngeo2413
Many scientists assume that the growing level of carbon dioxide in the atmosphere will accelerate plant growth. However, a new study co-written by University of Montana researchers suggests much of this growth will be curtailed by limited soil nutrients. "If society stays on its current trajectory of CO2 emissions and the growth rates of plants don't increase as much as many models project, the result by the end of the century could be more extreme than we predicted," said Cory Cleveland, a UM associate professor of biogeochemistry.
The study was published in the journal Nature Geoscience. Cleveland and former UM doctoral student Bill Smith did the research, along with partners at the University of Colorado and the Pacific Northwest National Laboratory
Mechanisms underpinning climatic impacts on natural populations: altered species interactions are more important than direct effects
Ockendon, N., Baker, D. J., Carr, J. A., White, E. C., Almond, R. E. A., Amano, T., Bertram, E., Bradbury, R. B., Bradley, C., Butchart, S. H. M., Doswald, N., Foden, W., Gill, D. J. C., Green, R. E., Sutherland, W. J., Tanner, E. V. J. and Pearce-Higgins, J. W. (2014), Mechanisms underpinning climatic impacts on natural populations: altered species interactions are more important than direct effects. Global Change Biology, 20: 2221–2229. doi: 10.1111/gcb.12559
Shifts in species' distribution and abundance in response to climate change have been well documented, but the underpinning processes are still poorly understood. This paper provides the results of a systematic literature review and meta-analysis investigating the frequency and importance of different mechanisms by which climate has impacted natural populations. Most studies were from temperate latitudes of North America and Europe; almost half investigated bird populations. Significantly greater support for indirect, biotic mechanisms were found than direct, abiotic mechanisms as mediators of the impact of climate on populations. In addition, biotic effects tended to have greater support than abiotic factors in studies of species from higher trophic levels. For primary consumers, the impact of climate was equally mediated by biotic and abiotic mechanisms, whereas for higher level consumers the mechanisms were most frequently biotic, such as predation or food availability. Biotic mechanisms were more frequently supported in studies that reported a directional trend in climate than in studies with no such climatic change, although sample sizes for this comparison were small. The authors call for more mechanistic studies of climate change impacts on populations, particularly in tropical systems.
Knowledge co-production and boundary work to promote implementation of conservation plans
This paper shows how working with stakeholders from diverse knowledge systems and creating shared knowledge boundaries to satisfy these different groups can help bridge the gap between conservation planning and implementation, and promote cross-sectorial cooperation. In this case knowledge co-production occurred in stakeholder workshops held over the course of four years. These iterative workshops included co-development of goals, dialogue and negotiation, and capacity building for multi-scale implementation. The resulting maps and information integrated diverse knowledge types of over 450 stakeholders and provide a consistent national information source that has been applied in 25 of the 37 use contexts since launching 3.5 years ago. This work provides practical guidance for conservation planners interested in promoting uptake of their science, and contributes to an evidence base for reflection on how conservation efforts can be improved.
Projected impacts of climate change on stream salmonids with implications for resilience-based management
Carlson, A. K., Taylor, W. W., Schlee, K. M., Zorn, T. G., & Infante, D. M. 2015. Projected impacts of climate change on stream salmonids with implications for resilience‐based management. Ecology of Freshwater Fish.
A recent study out of Michigan State University’s Department of Fisheries and Wildlife designed a stream model that predicts thermal habitat suitability for freshwater species. The study acted as supplemental research for the Michigan Department of Natural Resources’ efforts to develop a comprehensive management plan for the state’s stream salmonids. The study produced ranges of temperature sensitivities for stream brook charr, brown trout, and rainbow trout. The authors concluded by promoting their methodology of thermal habitat suitability projection as an effective resilience-based approach for supporting the sustainability of coldwater habitats and salmonid populations.
Anticipating effects of climate change on biodiversity
Molinos JG, Halpern BS, Schoeman DS, Brown CJ, Kiessling W, Moore PJ, Pandolfi JM, Poloczanska ES, Richardson AJ, Burrows MT (2015). Climate velocity and the future global redistribution of marine biodiversity. Nature Climate Change. doi: 10.1038/NCLIMATE2769
A new study examines the importance of anticipating the effects of climate change on biodiversity and particularly community composition for natural resources management. The study uses climate velocity trajectories, along with habitat preferences, to project global changes in marine species richness and community composition for two climate change scenarios, RCP 4.5 and 8.5. The authors find that climate change results in a net redistribution rather than a loss of biodiversity. However, at a local level, high extirpation rates are expected, such as in the Indo-Pacific, particularly under RCP 8.5.
Natural Resource Assessment of Mount Rainier National Park
Hoffman, Jr., R., Woodward, A., Haggerty, P., Jenkins, K.J., Griffin, P.C., Adams, M.J., Hagar, J., Cummings, T., Duriscoe, D., Kopper, K., Riedel, J., Samora, B., Marin, L., Mauger, G.S., Bumbaco, K., Littell, J.S. 2014. Mount Rainier National Park - Natural Resource Condition Assessment. Natural Resource Report: National Park Service NPS/MORA/NRR--2014/894, p. 380.
Researchers from the USGS and other organizations have completed a Natural Resource Condition Assessment
(NRCA) for Mount Rainier National Park (MORA). The report is an evaluation of current conditions for a subset of the park’s natural resources and resource indicators in relation to reference conditions and values. Additionally, the report describes influences and trends in resource conditions, highlights emerging issues, and identifies critical information requirements and data gaps. The report highlights 14 key indicators: air quality, water quality, climate change, landscape, wildlife, glaciers, riverine landforms, terrestrial vegetation, soundscapes, and night skies. This report will assist park managers in their near- and long-term efforts to describe the park’s resource conditions and desired management targets.
Microbes measure ecological restoration success
Nicholas J.C. Gellie, Jacob G. Mills, Martin F. Breed, Andrew J. Lowe. Revegetation rewilds the soil bacterial microbiome of an old field. Molecular Ecology, 2017; DOI: 10.1111/mec.14081
Scientists from the University of Adelaide in Australia have published a new method for monitoring ecological restoration sites. Called “high-throughput amplicon sequencing of environmental DNA (eDNA),” the technique examines changes in the composition of DNA found within the soil of a newly revegetated site. Using this method, the scientists were able to map a timeline of microbial recovery. In an old field that had been grazed for 100 years, the study showed full recovery of the microbial community after 8 years of restoration. The authors emphasized the importance of supplementing restoration monitoring plans with eDNA methods in order to gain a detailed understanding of the restoration process.
Maintaining species by translocating them to locations where climate is suitable
Thomas. 2011. Translocation of species, climate change, and the end of trying to recreate past ecological communities. Trends in Ecology & Evolution 26:216-221.
University of York researcher Chris Thomas argues that the only viable way to deal with species at high risk from climate impacts is to relocate them to other areas where the climate is suitable. Many species are unable to relocate themselves for a variety of factors (slow dispersal rates, unable to surmount human and natural obstacles, etc.), and these species need to be intentionally relocated to areas where they can survive. For example, some species are endemic to the summit of a particular mountain range, and as temperatures warm, the temperature may no longer be cold enough for them to survive, thus they would need to be relocated. Thomas argues that this is the most effective way to reduce the extinction rates that are projected due to climate change impacts, thus it is currently the most viable method of reducing biodiversity losses.
Interactive map shows where animals will move under climate change
Joshua Lawler, a NW CSC- funded scientist from the University of Washington, and colleagues from the Nature Conservancy have produced an interactive map of the Western Hemisphere, illustrating where mammals, birds and amphibians are projected to migrate in response to climate change. The animated map is color coded for the aforementioned three animal classes, and shows a mass exodus toward northern regions, with empty black zones showing where large cities or landscape features like the Great Lakes block migration. The map predicts the Appalachian Mountains act as a highway for species moving north. In the west, mountain ranges and protected areas will also serve as conduits, but many of the higher mountains will also serve as refuges themselves. The researchers plan to calculate migration shifts for species in western regions of the U.S. at finer resolutions, then apply that information to find the places most important to protect for movement under climate change. Access the full map here: http://maps.tnc.org/migrations-in-motion/#4/19.00/-78.00.
Addressing and adapting to the current warming trend in the PNW
Raymond, Crystal L.; Peterson, David L.; Rochefort, Regina M., eds. 2014. Climate change vulnerability and adaptation in the North Cascades region, Washington. Gen. Tech. Rep. PNW-GTR-892. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 279 p. http://www.treesearch.fs.fed.us/pubs/47131
Over the past two years the North Cascadia Adaptation Partnership (NCAP) worked with stakeholder groups within the North Cascade region to recognize regional climate change issues relevant to resource management, and to address adaptation strategies that will help facilitate a transition into a warmer climate. In the PNW a 2.1 °C temperature increase is expected by the 2040s and a 3.8 °C increase by the 2080s. The warming climate will have significant regional effects for both aquatic and terrestrial ecosystems. Some of the effects of a warmer climate discussed in this paper include flooding, fluctuation in seasonal flows, reduction in fish habitat suitability, and fluctuations in productivity/growth in tree species. While adapting to and dealing with the aforementioned effects of altered climate is a challenge, this paper addresses adaptation strategies that increase the potential for the PNW ecosystems to remain functional in future decades.
Assessing Species Vulnerability to Climate Change
Pacifici, M., W. B. Foden, P. Visconti, J. E. M. Watson, S. H. M. Butchart, K. M. Kovacs, B. R. Scheffers, D. G. Hole, T. G. Martin, H. R. Akcakaya, R. T. Corlett, B. Huntley, D. Bickford, J. A. Carr, A. A. Hoffmann, G. F. Midgley, P. Pearce-Kelly, R. G. Pearson, S. E. Williams, S. G. Willis, B. Young, and C. Rondinini. 2015. Assessing species vulnerability to climate change. Nature Climate Change 5: 215-224. http://dx.doi.org/10.1038/nclimate2448
The effects of climate change on biodiversity are increasingly well documented, and many methods have been developed to assess species’ vulnerability to climatic changes, both ongoing and projected in the coming decades. To minimize global biodiversity losses, conservationists need to identify those species that are likely to be most vulnerable to the impacts of climate change. In this Review, the authors summarize different currencies used for assessing species’ climate change vulnerability. The authors describe three main approaches used to derive these currencies (correlative, mechanistic and trait-based), and their associated data requirements, spatial and temporal scales of application and modelling methods. They identify strengths and weaknesses of the approaches and highlight the sources of uncertainty inherent in each method that limit projection reliability. Finally, the authors provide guidance for conservation practitioners in selecting the most appropriate approach(es) for their planning needs and highlight priority areas for further assessments.
Climate change prompts fish to change breeding behavior
Hovel, R. A., Carlson, S. M. and Quinn, T. P. (2016), Climate change alters the reproductive phenology and investment of a lacustrine fish, the three-spine stickleback. Glob Change Biol. doi:10.1111/gcb.13531
A study led by biologists from the University of Washington examined the impact of climate change on growth and reproduction of high-latitude freshwater fish. Specifically, the study analyzed the biological and physical factors affecting Alaska’s three-spined stickleback fish using five decades of time series data. Their findings showed that three-spined stickleback spawned earlier in years when ice breakup occurred earlier. In some cases, this also resulted in the fish producing more than one brood. Lead author, Rachel Hovel, commented that “climate change literature features many predictions and vulnerability assessments, but we don’t have many opportunities to actually observe species’ responses over time, as this is very data-intensive. Our ability to detect multiple breeding in fish is attributed to our comprehensive and high-quality long-term dataset.” The study is inconclusive on whether these findings indicate a positive or negative climate-induced impact for the three-spined stickleback. Regardless, the study has pinpointed a way by which climate change is affecting high-latitude ecosystems.
Effects of climate change on bringing previously isolated species into contact
Krosby M, Wilsey CB, McGuire JL, Duggan JM, Nogeire TM, Heinrichs JA, Tewksbury JJ, Lawler JJ (2015) Climate-induced range overlap among closely related species. Nature Climate Change 5: 883-886. doi: 10.1038/NCLIMATE2699
Climate change is already resulting in large-scale changes in species distributions, and this is expected to worsen in the coming years. Consequently, it is thought that geographic overlap between previously isolated species might become a significant issue, leading to competition between species when species are already experiencing high levels of stress from altered environmental conditions. Moreover, previously isolated species might hybridize when brought into contact inadvertently. A new study examines these possibilities using bioclimatic models to predict effects on 9,577 congeneric pairs (meaning species of the same genus) between 2071-2100, including amphibians, birds and mammals. For bioclimatic models, the authors used an ensemble of 10 GCMs. In their results, they only included those that occurred in a majority (>5 of 10) GCMs. They found that projected rates of overlap were highest for birds (11.6%) followed by mammals (4.4%) and finally amphibians (3.6%). They suggest that actual rates may be even lower than these. As a result, it is likely that hybridization and competition between species pairs will not be a significant issue in the future.
How migratory birds respond to balmier autumns
Adrienne Berchtold, Ira Nightingale, Caitlin Vandermeer, Scott A. MacDougall-Shackleton. Experimental temperature manipulations alter songbird autumnal nocturnal migratory restlessness. Animal Migration, 2017; 4 (1): 1 DOI: 10.1515/ami-2017-0001
A new paper reports the results of lab experiments to investigate how temperature influences the urge to migrate in songbirds. The study was led by Adrienne Berchtold from the Advanced Facility for Avian Research at the University of Western Ontario. Her team focused on the white-throated sparrow, a species known to rely on weather to time its annual autumn journey from Canada to the southern U.S. They used specially-designed cages equipped with high-tech monitoring gear to track patterns of activity while varying room temperatures. When the temperature dropped to 4ºC, the birds became restless at night, signifying they were in a migratory state. When the temperature was raised to 24ºC, none of the birds showed signs of migratory restlessness, indicating an urge to stay. These results suggest that increases in autumn temperatures could delay migration. Another possibility is that the birds could decide to forego migration altogether, as is happening in certain populations of American Robins.
Bird and other animal responses to extreme climatic events: challenges and directions
Martijn van de Pol, Stéphanie Jenouvrier, Johannes H. C. Cornelissen, Marcel E. Visser. 2017. Behavioural, ecological and evolutionary responses to extreme climatic events: challenges and directions. Philosophical Transactions of the Royal Society B: Biological Sciences; 372 (1723): 20160134 DOI: 10.1098/rstb.2016.0134
Evidence suggests that the impact of extreme events on animal behavior, ecology and evolution could well be greater than that of the ‘normal’ periods in between. Climate change is expected to increase the frequency of extreme events, but predicting the consequence of this environmental change on species of plants and animals can be problematic. In a special June issue of Philosophical Transactions of the Royal Society B researchers launch a new approach to investigating the impact of extremes, outliers, cataclysms on species. One study in the issue examined the evolutionary response to climate change of oystercatchers that build their nests close to the coast despite rising sea levels. Another studied fairy-wrens — Australian passerine birds — that are increasingly exposed to heatwaves and high temperatures, with sometimes fatal consequences. Over 20 years the number of flooding events that destroy oystercatcher nests has more than doubled, yet oystercatchers do not nest on higher ground in response. Data on fairy wrens, collected over nearly 40 years, shows that two very similar species respond to increasing heat waves in completely different ways. Authors conclude with a suggested 'roadmap' for the further development of this new area of research, aimed at making it easier to compare and synthesize information across fields.
Biodiversity modeling and network analysis illustrate the importance of habitat connectivity
Thompson, P.L. & A. Gonzalez. 2017. Dispersal governs the reorganization of ecological networks under environmental change. Nature Ecology & Evolution, 1: 0162 DOI: 10.1038/s41559-017-0162
This article outlines recent research about the importance of keeping habitats connected, particularly in the face of environmental change. Researchers from the University of British Columbia and McGill University worked together to integrate biodiversity modeling and network analysis to better understand how complex ecological networks may reorganize in the future. One key finding was that, if habitats remain connected, species will have more opportunity to move in response to environmental change, which facilitates ecosystem resilience. In their models, researchers found that this movement not only prevented extinction, but also allowed complex networks to maintain their structure. This research took a unique approach by analyzing the ‘wiring’ of ecological webs and how those connections may change in the future.
How biodiversity buffers fisheries against climate change
Duffy, J.E., Lefcheck, J.S., Stuart-Smith, R.D., Navarrete, S.A., Edgar, G.J. 2016. Biodiversity enhances reef fish biomass and resistance to climate change. Proceedings of the National Academy of Sciences. doi: 10.1073/pnas.1524465113
An international team of researchers used data collected by citizen scientist SCUBA divers at nearly 2,000 sites around the world to investigate relationships between biodiversity and biomass. They found that warmer water temperatures increase biomass, but temperature variability decreases it. They also found that sites with greater species richness and diversity had higher biomass, and that species diversity was the second strongest predictor of biomass. Analysis showed that, while changing temperatures did reduce reef fish biomass, the effect was halved in the most diverse ecosystems. That’s “possibly because species-rich communities harbor fishes with a range in thermal niches,” speculate the authors. More biodiverse ecosystems are simply more likely to include fish species able to withstand the coming changes. The study underscores the fact that conserving individually important species is not enough. Instead, the primary target of marine conservation should be biodiversity. Indeed, the researchers concluded, “biodiversity is equally and often more important than water quality, nutrient supply, and human influence in controlling the global distribution of reef fish biomass.” Conservation efforts that have biodiversity as a goal will therefore be best able to ensure the continued availability of fish as a key source of human nutrition.
Saving bull trout from a warming climate
A news story about ecologists attempting a radical new method in conservation biology: physically relocating species that will not survive in their current habitat with a rapidly warming climate. Clint Muhlfeld with the USGS is undertaking one of the largest relocation projects to date, moving bull trout populations to higher elevation lakes in Montana. The project is in its early experimental stages and displays a “herculean” scientific effort to save the most vulnerable of trout species from a man-made environmental threat.
Towards a threat assessment framework for ecosystem services
Martine Maron et al. 2017. Towards a Threat Assessment Framework for Ecosystem Services. Trends in Ecology and Evolution. DOI: 10.1016/j.tree.2016.12.01
Ecosystem services, or the ways in which people benefit from nature, are essential for human well-being, but are less understood, particularly when it comes to services at risk of undersupply. University of Queensland scientist, Martine Maron, led a study recently published in Trends in Ecology and Evolution that developed a framework for identifying threatened services by analyzing supply and demand. The authors hope the framework can be used in concert with existing assessments of threat to species and ecosystems in order to progress toward more effective land management. The study’s co-author, Matthew Mitchell, provided an example of poorly managed land in an interview with the University of Queensland; “An example we often see in our cities is the loss of vegetation and its ability to intercept rainwater and reduce flooding. People continue to develop flood-prone areas while also clearing vegetation and building on upstream slopes, so floods are becoming more common and damaging.”
Assessing impacts of projected climate change on biodiversity in protected areas of western North America
Langdon, J. G., & Lawler, J. J. (2015). Assessing the impacts of projected climate change on biodiversity in the protected areas of western North America. Ecosphere, 6(5), art87.
A new study examines the climate-driven ecological change within protected area networks in order to help managers develop more effective climate-adaptation strategies. University of Washington scientists Jesse Langdon and Joshua Lawler quantified this projected change using three metrics: future projected changes in temperature and precipitation, shifts in major vegetation types, and vertebrate species turnover for the protected areas of the Pacific Northwestern region of North America. This study found that low elevation areas near the coast and throughout the Coastal Mountains were expected to experience the least climate-driven ecological change, whereas the higher elevation areas in the Rocky Mountains and Great Basin were expected to experience the most change. These findings will support the need to develop appropriate, location-specific climate-adaptation strategies for protected areas in response to disparate trends in future environmental change.
Biodiversity experts weigh in on controversial conservation measures to address climate change
Hagerman, S.M., and T. Satterfield. 2014. Agreed but not preferred: Expert views on taboo options for biodiversity conservation, given climate change. Ecological Applications 24(3): 548-559. http://cses.washington.edu/db/pubs/abstract828.shtmlHagerman, S.M., and T.
This paper investigated the level of agreement among biodiversity experts on various approaches to protect biodiversity from the projected effects of climate change using a web-based survey completed by respondents worldwide, but with a focus on the Pacific Northwest. Experts strongly agreed that climate change will substantially impact species and ecosystems in the upcoming decades. However climate change ranked as a lower concern than habitat loss/degradation, industrial harvesting and urban expansion. The study distinguished between more conventional approaches to adaptation and less conventional, or so-called “taboo” approaches. When compared to former studies, respondents from this survey indicated a growing receptivity towards “taboo” options. Most experts overwhelmingly agreed that, not only will climate change have widespread impacts on species and their habitats; but also that the current framework designed for adaptive management (i.e. conventional actions) are insufficient to address the detrimental effects. Despite consensus about the broad consequences of climate change and the need for adaptation, the scientific uncertainty about the particular timing and magnitude of specific impacts pose significant barriers to implementing plans.
Elevated CO2 further lengthens growing season under warming conditions
Reyes-Fox, Melissa, Heidi Steltzer, M. J. Trlica, Gregory S. McMaster, Allan A. Andales, Dan R. LeCain and Jack A. Morgan. 2014. Elevated CO2 further lengthens growing season under warming conditions. Nature 510: 259-262. doi: 10.1038/nature13207
Here, researchers show that experimental warming in a temperate grassland led to a longer growing season through earlier leaf emergence by the first species to leaf, often a grass, and constant or delayed senescence by other species that were the last to senesce, supporting the conceptual model. Elevated CO2 further extended growing, but not reproductive, season length in the warmed grassland by conserving water, which enabled most species to remain active longer. These results suggest that a longer growing season, especially in years or biomes where water is a limiting factor, is not due to warming alone, but also to higher atmospheric CO2 concentrations that extend the active period of plant annual life cycles.
Warm-water years are tough on juvenile salmon
Daly, E.A. and Brodeur, R.D. 2015. Warming Ocean Conditions Relate to Increased Trophic Requirements of Threatened and Endangered Salmon. PloS one, 10(12).
A recently published study conducted by researchers from Oregon State University and NOAA examines the effect of water temperature on Chinook salmon foraging habits and overall health. The study evaluated 19 years (1981-1985, 1998-2011) of juvenile salmon surveys and discovered that when water is warmer than average, young salmon consume 30 percent more food than during cold-water regimes. Despite this higher consumption, the salmon studied under warm water conditions were found to be smaller and skinnier. This is likely due to the fact that warmer water requires salmon to eat more in order to keep their metabolic rate up, which causes them to work harder for food. In addition, the food is less nutritious due to the lack of lipid-rich prey available during warm water conditions. Warmer water conditions have been occurring in the waters off the Pacific Northwest for the past two years due to “The Blob”. The researchers of this study conclude by stressing that as warm water persists, the ability for young salmon to find enough food will drastically decline.
Snowshoe hares display limited phenotypic plasticity to mismatch in seasonal camouflage
Zimova, M., L. S. Mills, P. M. Lukacs, and M. S. Mitchell. 2014. Snowshoe hares display limited phenotypic plasticity to mismatch in seasonal camouflage. Proceedings of the Royal Society B: Biological Sciences 281. doi: 10.1098/rspb.2014.0029
Plasticity in moult phenology and behaviours in snowshoe hares has been found to be insufficient for adaptation to camouflage mismatch, suggesting that any future adaptation to climate change will require natural selection on moult phenology or behaviour…. As duration of snow cover decreases owing to climate change, species undergoing seasonal colour moults can become colour mismatched with their background. The immediate adaptive solution to this mismatch is phenotypic plasticity, either in phenology of seasonal colour moults or in behaviours that reduce mismatch or its consequences. Researchers observed nearly 200 snowshoe hares across a wide range of snow conditions and two study sites in Montana, USA, and found minimal plasticity in response to mismatch between coat colour and background. It was found that moult phenology varied between study sites, likely due to differences in photoperiod and climate, but was largely fixed within study sites with only minimal plasticity to snow conditions during the spring white-to-brown moult. No evidence was found that hares modify their behaviour in response to colour mismatch. Hiding and fleeing behaviours and resting spot preference of hares were more affected by variables related to season, site and concealment by vegetation, than by colour mismatch.
Study Finds Global Warming as Threat to 1 in 6 Species
Urban, M. 2015. Accelerating extinction risk from climate change. Science: 348(6234) pp. 571-573. doi: http://dx.doi.org/10.1126/science.aaa4984
Current predictions of extinction risks from climate change vary widely depending on the specific assumptions and geographic and taxonomic focus of each study. Mark Urban from the University of Connecticut synthesized published studies in order to estimate a global mean extinction rate and determine which factors contribute the greatest uncertainty to climate change–induced extinction risks. Results suggest that extinction risks will accelerate with future global temperatures, threatening up to one in six species under current policies. Extinction risks were highest in South America, Australia, and New Zealand, and risks did not vary by taxonomic group. Realistic assumptions about extinction debt and dispersal capacity substantially increased extinction risks. We urgently need to adopt strategies that limit further climate change if we are to avoid an acceleration of global extinctions.
Exotic plant invasions under enhanced rainfall are constrained by soil nutrients and competition
Anu Eskelinen and Susan Harrison. 2014. Exotic plant invasions under enhanced rainfall are constrained by soil nutrients and competition. Ecology 95:682–692. http://dx.doi.org/10.1890/13-0288.1
To predict the net impact of climate change on invasions, it is critical to understand how its effects interact with environmental and biotic context. In a factorial field experiment, we examined how increased late-season rainfall influences the growth and reproductive success of two widespread invasive species (Centaurea solstitialis and Aegilops triuncialis) in heterogeneous Californian grasslands, and, in particular, how its impact depends on habitat type, nutrient addition, and competition with resident species. Rainfall enhancement alone exhibited only weak effects, especially in naturally infertile and relatively uninvaded grasslands. In contrast, watering and fertilization together exhibited highly synergistic effects on both invasive species. However, the benefits of the combined treatment were greatly reduced or offset by the presence of surrounding competitors. Our results highlight the roles of nutrient limitation and biotic resistance by resident competitors in constraining the responses of invasive species to changes in rainfall. In systems with strong environmental control by precipitation, enhanced rainfall may promote invasions mainly under nutrient-rich and disturbed conditions, while having lesser effects on nutrient-poor, native “refuges.”
Seasonal not annual rainfall determines grassland biomass response to carbon dioxide
Hovenden, M., et al., Nature, 2014/07/31/print, Vol 511, Issue 7511, pp 583-586, http://dx.doi.org/10.1038/nature13281
Large annual variation in the stimulation of above-ground biomass by elevated carbon dioxide in a mixed C3/C4 temperate grassland can be predicted accurately using seasonal rainfall totals.
Conserving Biodiversity: Practical Guidance about Climate Change Adaptation Approaches in Support of Land-use Planning
Lawler, J.J., Beier, P., Groves, G., Knight, G., Boyce Jr, D.A., Bulluck, J., Johnston, K.M., Klein, M.L., Muller, K., Pierce, D.J., Singleton, W.R., Strittholt, J.R., Theobald, D.M., Tombulak, S.C., and Trainor, A. (2015) Conserving Biodiversity: Practical Guidance about Climate Change Adaptation Approaches in Support of Land-use Planning. Natural Areas Journal 35(1)
This paper presents a framework that synthesizes six promising adaptation approaches for conserving biodiversity. The authors provide guidance on implementing these adaptation approaches and include case studies that highlight how biodiversity conservation can be used in planning. It concludes with general guidance on choosing appropriate climate adaptation approaches to amend for conservation planning.
Climate change may benefit native oysters, but there's a catch
Brian S. Cheng et al. Trophic sensitivity of invasive predator and native prey interactions: integrating environmental context and climate change. Functional Ecology, October 2016 DOI: 10.1111/1365-2435.12759
A recent study from the University of California, Davis, examined the projected impacts of climate change on the oyster populations along the California coast. Published in Functional Ecology, researcher Brian Cheng and colleagues measured the thermal and saline parameters of the Olympia oyster (native species to the West coast of North America) and the oyster drill (invasive snail species that eats oysters). While extreme conditions, such as warmer temperatures and lower salinity, actually benefit oysters because they tend to grow faster, the study shows that these climate change-induced environmental conditions will benefit their predators (the oyster drill) first, subsequently reducing the oyster population.
Climate change may be worse for lizards than previously thought
Sears, M.W., Angilletta Jr., M.J., Schuler, M.S., Borchert, J., Dilliplane, K.F., Stegman, M., Rusch, T.W. & Mitchell, W.A. 2016. Configuration of the thermal landscape determines thermoregulatory performance of ectotherms. PNAS, DOI: 10.1073/pnas.1604824113
A team of biologists recently advanced our understanding of animal thermoregulatory behavior in a way that has important implications for conservation. Biologist Michael Sears from Clemson University and colleagues used spiny lizards to study how the distribution of shade within an animal’s habitat impacts its thermoregulatory behavior. The authors modeled spatially explicit movements of animals constrained by access to thermal resources, and showed that habitats with many small patches of shade and sun were preferred over areas with one large shaded area because the lizards were able to quickly and efficiently reach shade to cool off. The results from this study reveal a complexity to climate change modeling that has formerly been neglected. Implications of this study extend to all models researching the impact of climate change on animal behavior, suggesting that more accurate predictions will come from sophisticated fine-scale environments.
Bioinvasions in a Changing World
This report, released by the Aquatic Nuisance Species Task Force (ANSTF) and the National Invasive Species Council (NISC), is intended for a broad audience of individuals interested in invasive species, climate change, and natural resource management. The report provides a brief overview of the connections between invasive species and climate change before evaluating how communities approach conservation and natural resource management. The report addresses a broader framework of invasive species management and climate change adaptation as tools to enhance and protect ecosystems and natural resources in the face of these drivers of change. The review of tools and methods will be of interest to managers working at specific sites and to individuals making strategic decisions at larger geographic scales.
Air Pollution May Cause Increasing Levels of Mercury in Pacific Tuna
Drevnick, P.E., Lamborg, C.H., Horgan, M.J. 2015. Increase in mercury in Pacific yellowfin tuna. Environmental Toxicology and Chemistry. doi: http://dx.doi.org/10.1002/etc.2883
A recent study published in Environmental Toxicology and Chemistry found that the concentration of mercury in yellowfin tuna is increasing at a rate of at least 3.8% per year - providing evidence that burning coal is affecting the ocean food chain. This increase is consistent with a model of anthropogenic forcing on the mercury cycle in the North Pacific Ocean and suggests that fish mercury concentrations are keeping pace with current loading increases to the ocean. Future increases in mercury in yellowfin tuna and other fishes can be avoided by reductions in atmospheric mercury emissions from point sources.
Climate change is increasing hybridization between native and invasive trout in the West
Muhlfeld CC, Kovach RP, Al-Chokhachy R, et al. In press. Legacy introductions and climatic variation explain spatiotemporal patterns of invasive hybridization in a native trout. Global Change Biology 00:1–11. https://doi.org/10.1111/gcb.13681
A team of US Geological Survey researchers and partners investigated how native and invasive lake trout have interbred, or hybridized, across the northern Rocky Mountains over time. They integrated large genetic datasets with high resolution climate predictions and fish stocking records. They found an increased spread of hybridization that was mostly driven by historical fish stocking, warming water temperatures, increased road densities and decreased spring precipitation. Hybridization between invasive and native species can threaten biodiversity, and these results suggest that human activities can greatly impact biodiversity. Thus, researchers recommend that analysis on how climate change may affect biodiversity in the future must be considered in context of past and present human impacts.
Marine travellers best able to adapt to warming waters
Sunday, J.M; Pecl, G.T.; Frusher, S.; Hobday, A.J.; Hill, N.; Holbrook, N.J.; Edgar, G.J.; Stuart-Smith, R.; Barrett, N.; Wernberg, T.; Watson, R.A.; Smale, D.A.; Fulton, E.A.; Slawinski, D.; Feng, M.; Radford, B.T.; Thompson, P.A.; Bates, A.E. 2015. Species traits and climate velocity explain geographic range shifts in an ocean-warming hotspot. Ecology Letters. Doi: 10.1111/ele.12474
Due to extensive dam removal and habitat restoration, this year has brought record runs of juvenile Coho salmon in Goldsborough Creek. The previous record was 61,000 Coho, and this year 113,000 juveniles were counted. This was a major success; fifteen years ago, the US Army Corps of Engineers removed a dam on Goldsborough, and since then, the Squaxin Island Tribe has worked closely with other partners to improve the habitat for fish. The dam removal was significant, as it opened up access to wetlands. This is essential for the lifecycle of Coho salmon, which spend an additional year in freshwater before going out to sea (unlike most species of salmon). According to Andy Whitener, natural resources director for the Squaxin Island Tribe, this year’s record points to the importance of habitat for salmon, and to the potential for habitat restoration projects to lead to dramatic improvements.
Marine travellers best able to adapt to warming waters: Researchers at the University of Southampton and an international team of biodiversity experts found that marine species with smaller migration ranges are at high risk due to climate change, while marine species with large migration ranges face smaller risks due to being more adaptable. University of British Columbia biodiversity research Jennifer Sunday, lead author of the study, showed how marine species with higher adult mobility demonstrated the ability to adapt to warming oceans by migrating to cooler waters. These same species are typically habitat generalists and were at equilibrium with their environments, allowing them to respond to warming temperatures by shifting their migration patterns. The study site was located off of Australia’s east coast, where the ocean has been warming at four times the global average rate. Marine species have been observed further south than ever before as a result of this. Species observed included the tiger shark, short-tail stingray and barren-forming urchin, along with a number of notoriously invasive omnivore fish species.
Some fish are adjusting body defenses to deal with acidification
Schunter, C., Welch, M.J., Ryu, T., Zhang, H., Berumen, M.L., Nilsson, G.E., Munday, P.L., & Ravasi, T. 2016. Molecular signatures of transgenerational response to ocean acidification in a species of reef fish. Nature Climate Change doi:10.1038/nclimate3087
In a recently published study, scientists examined the natural ability of certain fish to adapt to changes in ocean acidification. They found their subject, spiny damselfish, to be capable of adapting to higher CO2 levels as part of the genetic mechanisms organizing their circadian clocks. This natural ability is driven by the need to accommodate the diurnal variation in ocean CO2 levels that occurs with the inactivity of photosynthesizing organisms at night. The authors of this study bred damselfish in water with near-future carbon dioxide levels and found that the fish that produced offspring with more flexible circadian clocks were able to better adjust to the high-CO2 environment. "It seems the tolerant offspring may have adjusted their circadian clocks as if it was always night," said Timothy Ravasi, one of the authors of the study at King Abdullah University of Science and Technology in Saudi Arabia.
Wildlife Groups ask FWS to Classify Gray Wolves as Threatened
Impending regulatory and legislative measures to remove federal protections from most gray wolves prompted animal protection and conservation groups to call on the Fish and Wildlife Service to instead reclassify nearly all gray wolves in the U.S. as threatened – a lower level of protection than many wolf populations have. Currently, gray wolves are listed under the Endangered Species Act (ESA) as endangered throughout most of the species’ range in the continental U.S. However, wolf populations in Montana, Idaho, eastern Oregon, and Washington are exceptions to that rule, where populations are not listed as threatened. "The reclassification of gray wolves to threatened status is warranted at this time because of the differing conservation status among wolf populations in different portions of the species' range," the 32-page request argued.
Effects of climate, habitat and Barred Owls on demography of Northern Spotted Owls
Dugger, C. et al. 2016. The effects of habitat, climate, and Barred Owls on long-term demography of Northern Spotted Owls. Condor, 188 (1).
This reports presents results from field data collected during 1985–2013 to evaluate population processes of Northern Spotted Owls across its range in Washington, Oregon, and northern California. The authors estimated factors relating to survival and reproductive success, and investigated relationships between these parameters and the amount of suitable habitat, various climatic variables, and competition with Barred Owls. Estimated mean annual rates of population decline varied from 1.2% to 8.4% among study sites, with a weighted mean range-wide decline of 3.8%. Climate covariates were important in most models of spotted owl fecundity and survival, but there was little consistency among areas regarding the relative importance of specific climate covariates for survival. In contrast, meta-analysis results suggested that Spotted Owl survival was higher across all study areas when the Pacific Decadal Oscillation (PDO) was in a warming phase and the Southern Oscillation Index (SOI) was negative, with a strongly negative SOI indicative of El Niño events. The authors conclude that Northern Spotted Owl populations are declining throughout their range, and that rates of decline are accelerating in many areas. They posit that Barred Owl densities may now be high enough that the persistence of Northern Spotted Owls may be in question without additional management intervention.
Northwest Mountain Amphibians and their Changing Wetlands
Each year from Mt. Rainier to Mt. St. Helens the seasons run their cycle as the snow perched atop the Northwest’s majestic, high elevations melts, eventually winding its way to the Pacific Ocean. Along its gravity-propelled journey, this water fills montane lakes and streams, providing essential habitat for species such as alpine frogs and salamanders, while also feeding streams carrying young salmon—not to mention fresh water for towns and farms—downstream. Sadly, this process is now threatened by climate change, which has been diminishing the region’s snowpack. Especially imperiled are montane amphibians.
Climate Change Challenges Adaptive Potential of Pacific Salmon
Munoz NJ, Farrell AP, Heath JW, Neff BD (2015) Adaptive potential of a Pacific salmon challenged by climate change. Nature Climate Change 5: 163-166. doi: 10.1038/nclimate2473
In this study, the authors argue that while Pacific salmon has physiological and genetic capacities to increase thermal tolerance with rising temperatures, there is an upper thermal limit corresponding to an increase of 2.2 degrees Celsius. To test Chinook salmon response to climate change, they mated wild-caught adult salmon and reared offspring from each family in current and projected future (increase of 4 degrees Celsius) temperature conditions. Based on their results and average warming projections, they predict a 5% change of ‘catastrophic loss’ by 2075 and a 17% change by 2100. For maximum warming projections, this increases to 55% by 2075 and 98% by 2100. They conclude that mitigation of climate change must occur to ensure the continuation of Pacific salmon populations. They note that adaptive capacity might increase if salmon species can acclimatize over multiple generations and pass that adaptive capacity on to their offspring. Some evidence is provided in favor of this, but not enough is known to incorporate this possibility into projections of adaptation.
Foundation of aquatic life can rapidly adapt to global warming
C.-Elisa Schaum, Samuel Barton, Elvire Bestion, Angus Buckling, Bernardo Garcia-Carreras, Paula Lopez, Chris Lowe, Samraat Pawar, Nicholas Smirnoff, Mark Trimmer, Gabriel Yvon-Durocher. 2017. Adaptation of phytoplankton to a decade of experimental warming linked to increased photosynthesis. Nature Ecology & Evolution; 1: 0094 DOI: 10.1038/s41559-017-0094
A team of scientists from the University of Exeter discovered formerly unknown adaptation mechanisms of phytoplankton. In this recently published study, scientists investigated the response of one species of green algae, Chlamydomonas reinhardtii, to warming in a 10-year-long laboratory experiment. The study found phytoplankton in the warmer environment displayed increased fitness in the new thermal conditions compared to phytoplankton from non-elevated temperatures. This result shows the capability of phytoplankton to rapidly adapt to warming. In particular, their evolutionary response consisted of producing higher rates of photosynthesis and therefore more energy, faster growth, and increased fitness. In an interview, scientist and lead author Elisa Schaum concluded, “although the green algae monitored in our study cope well with elevated temperature, and may be able to sustain populations of organisms that eat them, we do not know yet what will happen to other groups of algae, and whether or not they will adapt through the same mechanisms.”
What a fruit fly’s body temperature could reveal about climate change
Macmillan, H. A., Knee, J. M., Dennis, A. B., Udaka, H., Marshall, K. E., Merritt, T. J., & Sinclair, B. J. (2016). Cold acclimation wholly reorganizes the Drosophila melanogaster transcriptome and metabolome. Sci. Rep. Scientific Reports, 6, 28999. doi:10.1038/srep28999
According to an article published in Scientific Reports, an international study led by Canadian environmental physiologist Heath MacMillan has found that fruit flies adjust to a sudden drop in temperature by drastically changing their genes and metabolism. Researchers raised fruit flies from eggs through to their maggot stages at a room temperature of 21°C, and transferred them to a 6°C space once they were mature. The flies adjusted to the so-called “chill coma” by changing about a third of their 15,000 genes. The finding is important because understanding insects’ temperature tolerance is a crucial step in protecting and controlling insects worldwide, and could someday help scientists unravel the effects of climate change on insects.
Pacific salmon challenged by warming waters
Muñoz, N.J., Farrell, A.P., Heath, J.W., and Neff, B.D. 2014. Adaptive potential of a Pacific salmon challenged by climate change. Nature Climate Change. doi: http://dx.doi.org/10.1038/nclimate2473
This paper investigates the ability of Chinook salmon to adapt to warming water temperatures caused by climate change. The researchers found that the salmon developed cardiac irregularities in waters warmer than 24.5°C. Based on an average warming projection, researchers predict a 17% chance of “catastrophic” loss in the population by 2100, with this chance increasing to 98% in a maximum warming scenario. A constraint on the upper limit of thermal tolerance highlights the susceptibility of Pacific salmon populations to projected increases in temperature.
A new vulnerability assessment provides insights into where the effects of future ocean acidification will likely be greatest
Marshall, K. N., Kaplan, I. C., Hodgson, E. E., Hermann, A., Busch, D. S., McElhany, P., Essington, T. E., Harvey, C. J. and Fulton, E. A. (2017), Risks of ocean acidification in the California Current food web and fisheries: ecosystem model projections. Glob Change Biol. doi:10.1111/gcb.13594
A recent vulnerability assessment conducted on the the California Current, an upwelling system that already experiences inherently low pH conditions, suggests that Dungeness crab fisheries, valued at about $220 million annually, may face a strong downturn over the next 50 years. Dungeness crabs will likely suffer from ocean acidification as their food sources decline. In contrast, pteropods and copepods, tiny marine organisms with shells that are vulnerable to acidification, will likely experience only a slight overall decline because they are prolific enough to offset much of the impact. Marine mammals and seabirds are less likely to be affected by ocean acidification, the study found.
Reversing defaunation: Restoring species in a changing world
Philip J. Seddon et al., Science 345, 406 (2014); DOI: 10.1126/science.1251818
The rate of biodiversity loss is not slowing despite global commitments, and the depletion of animal species can reduce the stability of ecological communities. Despite this continued loss, some substantial progress in reversing defaunation is being achieved through the intentional movement of animals to restore populations. The authors review the full spectrum of conservation translocations, from reinforcement and reintroduction to controversial conservation introductions that seek to restore populations outside their indigenous range or to introduce ecological replacements for extinct forms. The popular, but misunderstood, concept of rewilding is placed within this framework and the authors consider the future role of new technical developments such as de-extinction.
Conservation blueprint completed for Columbia Plateau Ecoregion
To aid managers in strategic conservation efforts in the Columbia Plateau Ecoregion, the Great Northern LCC funded a two-year landscape conservation design project. The recently completed project, led by the US Fish & Wildlife Service's National Wildlife Refuge planning office, and in collaboration with the Arid Lands Initiative, used spatial analyses to identify priority areas for restoration and protection of habitats and species. This will allow conservation partners to work from a common blueprint for on-the-ground conservation actions and in developing management strategies adapted to a changing climate.
Migratory bird phenology in a changing climate
Biologist, Madeleine Rubenstein, discussed current research initiatives studying the impact of climate change on wildlife phenology in an article from The Wildlife Society. In the article, Rubenstein writes about the known effects climate change has on wildlife phenology, including the timing of bird migration, plants putting out leaves, and insect emergence. The author explains how wildlife phenology normally exhibits a synchrony among species, but turns into a cacophony with anthropogenic change to climate. The United States Geological Survey’s National Climate Change and Wildlife Science Center and the Department of Interior's Climate Science Centers are heading key research initiatives to better understand phenological shifts across various ecoregions. Read the article to further learn about the diversity of research currently underway, as well as projects containing citizen science opportunities.
A continental risk assessment of West Nile virus under climate change
Harrigan, R. J., Thomassen, H. A., Buermann, W. and Smith, T. B. 2014. A continental risk assessment of West Nile virus under climate change. Global Change Biology 20: 2417–2425. doi: 10.1111/gcb.12534
Projected geographic distributions of WNV in North America under future climate for 2050 and 2080 show an expansion of suitable climate for the disease, driven by warmer temperatures and lower annual precipitation that will result in the exposure of new and naïve host populations to the virus with potentially serious consequences. This risk assessment identifies current and future hotspots of West Nile virus where mitigation efforts should be focused and presents an important new approach for monitoring vector-borne disease under climate change.
Slow Climate Velocities on Mountain Streams Diminishes Climate-related Effects on Cold-water Species
Isaak, D. J., Young, M. K., Luce, C. H., Hostetler, S. W., Wenger, S. J., Peterson, E. E., Nagel, D. E. (2016). Slow climate velocities of mountain streams portend their role as refugia for cold-water biodiversity. Proceedings of the National Academy of Sciences. http://doi.org/10.1073/pnas.1522429113
Daniel Isaak and colleagues from the Rocky Mountain Research Station recently published a study examining the current predictions of short-term montane species loss due to large increases in stream temperature. The team of scientists used large databases of water temperature in order to diminish the effects of influential variables such as inaccuracy in smaller datasets and surrogate factors like elevation and air temperature. The study found a less dramatic shift in temperature for mountain streams suggesting a smaller threat to cold-water biodiversity. The authors concluded that mountains streams, due to local topographic controls on temperature, could in fact become important refugia for such species.
Climate warming mediates negative impacts of rapid pond drying for three amphibian species
Sacha M. O'Regan, Wendy J. Palen, and Sean C. Anderson. 2014. Climate warming mediates negative impacts of rapid pond drying for three amphibian species. Ecology 95:845–855. http://dx.doi.org/10.1890/13-0916.1
This study conducted a mesocosm experiment to test the individual and interactive effects of pool permanency (permanent vs. temporary) and water temperature (ambient vs. +∼3°C) on three anurans with fast-to-slow larval development rates (Great Basin spadefoot [Spea intermontana], Pacific chorus frog [Pseudacris regilla], and northern red-legged frog [Rana aurora]). We found that although tadpoles in warmed pools reached metamorphosis 15–17 days earlier, they did so with little cost (<2 mm) to size, likely due to greater periphyton growth in warmed pools easing drying-induced resource competition. Warming and drying combined to act antagonistically on early growth (P = 0.06) and survival (P = 0.06), meaning the combined impact was less than the sum of the individual impacts. Warming and drying acted additively on time to and size at metamorphosis. These nonsynergistic impacts may result from cotolerance of larvae to warming and drying, as well as warming helping to offset negative impacts of drying. Our results indicate that combined pool warming and drying may not always be harmful for larval amphibians. However, they also demonstrate that antagonistic responses are difficult to predict, which poses a challenge to proactive conservation and management. Our study highlights the importance of considering the nature of multiple stressor interactions as amphibians are exposed to an increasing number of anthropogenic threats.
Winter bird communities in eastern North America are shifting, thanks partly to climate change
Princé, K. and B. Zuckerberg. 2014. Climate change in our backyards: the reshuffling of North America’s winter bird communities. Global Change Biology doi: 10.1111/gcb.12740.
Species that typically prefer warmer weather, such as chipping sparrows, Carolina wrens, and eastern bluebirds, are advancing north.
Estimating Climate Resilience for Conservation across Geophysical Settings
ANDERSON, M. G., CLARK, M. and SHELDON, A. O. (2014), Estimating Climate Resilience for Conservation across Geophysical Settings. Conservation Biology, 28: 959–970. doi: 10.1111/cobi.12272
Conservationists need methods to conserve biological diversity while allowing species and communities to rearrange in response to a changing climate. We developed and tested such a method for northeastern North America that we based on physical features associated with ecological diversity and site resilience to climate change. We comprehensively mapped 30 distinct geophysical settings based on geology and elevation. Within each geophysical setting, we identified sites that were both connected by natural cover and that had relatively more microclimates indicated by diverse topography and elevation gradients. We did this by scoring every 405 ha hexagon in the region for these two characteristics and selecting those that scored >SD 0.5 above the mean combined score for each setting. We hypothesized that these high-scoring sites had the greatest resilience to climate change, and we compared them with sites selected by The Nature Conservancy for their high-quality rare species populations and natural community occurrences. High-scoring sites captured significantly more of the biodiversity sites than expected by chance (p < 0.0001): 75% of the 414 target species, 49% of the 4592 target species locations, and 53% of the 2170 target community locations. Calcareous bedrock, coarse sand, and fine silt settings scored markedly lower for estimated resilience and had low levels of permanent land protection (average 7%). Because our method identifies—for every geophysical setting—sites that are the most likely to retain species and functions longer under a changing climate, it reveals natural strongholds for future conservation that would also capture substantial existing biodiversity and correct the bias in current secured lands.
Snow Decline Impacts Snowshoe Hare Fitness
Zimova, M., Mills, L. S. and Nowak, J. J. (2016), High fitness costs of climate change-induced camouflage mismatch. Ecol Lett, 19: 299–307. doi:10.1111/ele.12568
A recently published study from North Carolina State University examined the individual and population-level impacts of decreased snow cover duration on snowshoe hares. Snowshoe hares undergo seasonal color molts from white to brown that align with changes in snow cover from winter to spring, but could be threatened by a climate change-induced phenological mismatch. Zimova et al. (2016) tracked 186 snowshoe hares in Western Montana and found a strong selection on coat color molt phenology. The weekly survival of hares that mismatched their habitat was measured to be 4-7% lower than hares with camouflaged coats. The study concluded that this climate-change induced phenological mismatch will result in massive population declines over the next century unless individual variation in molt phenology allows for evolutionary adaptation.
Causes of warm-edge range limits: systematic review, proximate factors and implications for climate change
Cahill, A. E., M. E. Aiello-Lammens, M. Caitlin Fisher-Reid, X. Hua, C. J. Karanewsky, H. Y. Ryu, G. C. Sbeglia, F. Spagnolo, J. B. Waldron, and J. J. Wiens. 2014. Causes of warm-edge range limits: systematic review, proximate factors and implications for climate change. Journal of Biogeography 41:429-442
The factors that set species range limits underlie many patterns in ecology, evolution, biogeography and conservation. These factors have been the subject of several reviews, but there has been no systematic review of the causes of warm-edge limits (low elevations and latitudes). Although it is often assumed that warm-edge limits are set by biotic factors, our review shows that abiotic factors (primarily temperature) are supported more often among the species in these 125 studies. However, few studies both identify proximate causes and test alternative mechanisms, or examine the interaction between biotic and abiotic factors. Filling these gaps should be a high priority as warm-edge populations are increasingly driven to extinction by climate change.
Where should we prioritize biodiversity conservation, given climate change?
Carroll, C., Roberts, D.R., Michalak, J.L., Lawler, J.J., Nielsen, S.E., Stralberg, D., Hamann, A., McRae, B.H. and Wang, T. In press. Scale-dependent complementarity of climatic velocity and environmental diversity for identifying priority areas for conservation under climate change. Global Change Biology. DOI: 10.1111/gcb.13679
A team of scientists compared several common approaches to conservation planning focused on climate resilience across North America. They evaluated similarities in locations with high conservation priority and found that these areas are substantially different from each other in terms of both environmental diversity metrics and spatiotemporal metrics. Refugia, or areas where populations can survive in unfavorable conditions, were identified but not strongly linked with current conservation systems. The authors emphasize the important role that planners play in addressing uncertainty in conservation efforts and offer several integrative tools and approaches to more holistically approach ecological and physical processes impacted by climate change.
Meager snows spell trouble ahead for salmon
Warm winter temperatures in the mountains of the western United States this past winter sharply reduced the region's snowpack, which normally reaches its high point at this time each year. That snow typically serves as a vital water storage reservoir that is slowly released as the snow melts over the dry summer months. Without this snowmelt, stream flows are expected to drop sharply this summer, which in turn is expected to cause water temperatures to rise to a level unhealthy for migrating salmon. As a result, fisheries biologists expect a looming calamity for endangered salmon stocks this year.
Incorporating climate change into spatial conservation prioritization
K.R. Jones, J.E.M. Watson, H.P. Possingham, C.J. Klein. 2016. Incorporating climate change into spatial conservation prioritisation: A review. Biological Conservation, Volume 194, 121–130. doi:10.1016/j.biocon.2015.12.008
In this recently published article from Biological Conservation, scientists provide a review of the methods used to implement climate change-incorporated spatially-explicit priority adaptation actions (also called “spatial prioritization”). The authors evaluated a variety of methods by assessing the considered objectives, target impacts and actions, as well as the parameters and overall methodology. They then reviewed the benefits and weaknesses of each approach, and provided recommendations for improvement. Three conclusions included in their findings were (1) the variety of methods either forecasted species distributions or used robust planning principles, (2) human adaptation responses were widely ignored in spatial prioritisation, and (3) discrete climate impacts, like extreme events, must also be addressed.
Climate change alters plant biogeography in Mediterranean prairies along the West Coast, USA
Pfeifer-Meister L, Bridgham SD, Reynolds LL, Goklany ME, Wilson HE, Little CJ, Ferguson A, Johnson BR (2015). Climate change alters plant biogeography in Mediterranean prairies along the West Coast, USA. Global Change Biology. doi: 10.1111/gcb.13052.
In this study, the authors examine the effects of warming and increased precipitation on plant functional groups and diversity across a climate gradient of prairies in the Pacific Northwest. They find that declining soil moisture that arises from warming temperatures would decrease native plant diversity, alter plant composition and result in northern plant communities looking more like plant communities located farther south. They conclude that projected increases in drought in the Pacific Northwest will lead to an increased number of annual plants and a loss of forbs (herbaceous flowering plants). This will cause a shift in functional plant groups, in turn possibly altering ecosystem functioning in prairies of the Pacific Northwest.
The Many Dimensions of the Mt. Rainier Climate Crisis
Global warming is melting Mount Rainier’s glaciers at six times the historic rate. The meltwater runoff has lead to floods, rock falls, old-growth forest death, and is threatening historic national park buildings. As global warming intensifies, we need to decide: “Do we spend the money required to repair park roads every year? Do we move endangered plants and animals to places they can survive? What in the park is most worth saving? And how hard does it make sense to try?”
Climate Change Threatens Native Trout Diversity
Kovach, R. P., Muhlfeld, C. C., Wade, A. A., Hand, B. K., Whited, D. C., DeHaan, P. W., Al-Chokhachy, R. and Luikart, G. (2015), Genetic diversity is related to climatic variation and vulnerability in threatened bull trout. Global Change Biology. http://dx.doi.org/10.1111/gcb.12850
Scientists have discovered that the diversity of a threatened native trout species will likely decrease due to future climate change. Researchers have found that in native bull trout, genetic diversity – critical for species to adapt to a warming world – is already lowest where stream temperatures are warmest and winter flooding is highest. These trends are predicted to continue into the future, suggesting that this imperiled species is more susceptible to climate change than previously thought. “Genetic diversity is extremely depressed where future climatic conditions may be most challenging for bull trout,” said U.S. Geological Survey scientist Ryan Kovach, the lead author of the report. “Together, these results highlight that bull trout may have little resiliency in a warming world.” The study, published in Global Change Biology, combined estimates of stream habitat conditions, current and future stream temperatures and flows, and estimates of genetic diversity patterns in 130 bull trout populations from 24 watersheds across the Columbia River Basin. The bull trout was listed as "threatened" under the U.S. Endangered Species Act in 1998.
Testing how species respond to climate change
Eleanor K. O'Brien, Megan Higgie, Alan Reynolds, Ary A. Hoffmann, Jon R. Bridle. Testing for local adaptation and evolutionary potential along altitudinal gradients in rainforest Drosophila: beyond laboratory estimates. Global Change Biology, 2017; DOI: 10.1111/gcb.13553
A study recently published in Global Change Biology examined the adaptability of species to respond to climate change. Led by scientists from the University of Bristol, the research team tested the adaptability of the tropical rainforest fly, Drosophila birchii, by transplanting them in cages along mountain gradients that represent the species altitudinal limits and measuring their reproductive success. The study found that abundance was greater in cooler, high-altitude sites while species fitness was greater in warmer, low-altitude sites. There was no evidence of local adaptation as the team found very little genetic variation across gradients.
Rapid evolution may help some city creatures stand the heat
Diamond SE et al. 2017. Rapid evolution of ant thermal tolerance across an urban-rural temperature cline. Biological Journal of the Linnean Society.
Researchers from Case Western Reserve University in Ohio recently published a comparative study of the evolution of thermal tolerance in urban-rural acorn ants (Temnothorax curvispinosus). The study monitored ant colonies under urban and rural heat conditions. As urban environments are characterized by warmer temperatures, urban ant colonies exhibited more heat tolerance than rural ant colonies. This display of rapid adaption shows both fast-paced evolution as well as phenotypic plasticity within the species’ genome. Lead author Sarah Diamond stated, “Global data suggests that the acclimation response won’t be enough to respond to climate change, but some species, like the acorn ants, may evolve quickly enough.”
Feasibility of Reintroducing Native Fish: Case of Bull Trout
Dunham J., Gallo, K., Shively D., Allen, C., Goehring, B. 2011. Assessing the feasibility of native fish reintroductions: A framework applied to threatened bull trout. North American Journal of Fisheries Management 31:106-111.
In contrast to the previous article, this study shows how relocating threatened species can be problematic without sufficient attention to feasibility prior to implementation. The authors develop a feasibility framework that should be used to assess a relocation project prior to implementing it. The framework has two basic components: the ability for new habitats to support reintroduction and the potential for available donor populations in the new habitat to support reintroduction. The authors then applied this framework to the reintroduction of bull trout into the Clackamas River in Oregon.
Congressional rider threatens iconic grouse species protection
Congress is finalizing an omnibus appropriations bill for the fiscal year of 2015 containing a rider that would temporarily prohibit listing the Greater Sage-Grouse as an endangered species and would impede conservation efforts for the Gunnison Sage-Grouse. Historically, riders accepted into appropriations bills are long-lasting and, in many cases, permanent. The grouse rider undercuts major conservation efforts, and jeopardizes species recovery.
Birds Try to Dodge Climate Change in a Surprising Way
Bateman, B. L., Pidgeon, A. M., Radeloff, V. C., VanDerWal, J., Thogmartin, W. E., Vavrus, S. J. and Heglund, P. J. (2015), The pace of past climate change vs. potential bird distributions and land use in the United States. Glob Change Biol. doi:10.1111/gcb.13154
A recent study, published in Global Change Biology, identifies the unusual movement of birds as they respond to climate change. Bateman et al. quantified the pace and direction of change for various bird species' suitable climate space over the past 60 years. The results revealed new and surprising knowledge of how birds are reacting to a changing climate. Many birds were found to be shifting ranges at twice the speed formerly assumed. In addition to this unexpected drifting pace, the majority of species' distribution shifted west, northwest, and north. This result contradicted previous predictions that birds would only shift northward. This interesting range shift direction suggested to the authors that temperature was not the sole factor influencing bird species, and that other climate conditions were also changing bird behavior. The study also pointed out that the areas projected to become optimal suitable climate spaces for birds happen to be the same areas that humans are most interested in populating and developing.
Despite evolutionary inexperience, northern sockeye manage heat stress
Jonathan B. Armstrong, Eric J. Ward, Daniel E. Schindler, Peter J. Lisi. Adaptive capacity at the northern front: sockeye salmon behaviourally thermoregulate during novel exposure to warm temperatures. Conservation Physiology, 2016; 4 (1): cow039 DOI: 10.1093/conphys/cow039
Oregon State University biologist, Jonathan Armstrong, led a recent study examining the thermoregulatory abilities of sockeye salmon from the poleward extent of the species’ migratory range. Armstrong and colleagues analyzed the behavior of northern sockeye during a natural heat event in the Wood River watershed, a river system that feeds into Bristol Bay off the coast of Alaska. The researchers tagged adult sockeye with temperature trackers as they made their way back to freshwater to spawn. The researchers found that the northern sockeye managed to thermoregulate under heat stress as effectively as southern sockeye exposed to a much wider range of annual temperatures. Specifically, the study showed that fish moved to cooler waters (thermoregulated) when the surrounding water exceeded 12°C. The results of this research suggest a more ubiquitous sensitivity and adaptive capacity to temperature change across all sockeye salmon than previously expected.
Global warming kills gut bacteria in lizards
Bestion, E.; S. Jacob; L. Zinger; L. Di Gesu; M. Richard; J. White; & Julien Cote. 2017. Climate warming reduces gut microbiota diversity in a vertebrate ectotherm. Nature Ecology & Evolution, 1: 0161 DOI: 10.1038/s41559-017-0161
This article reports the results of a study suggesting that climate change may threaten reptiles by reducing the number of bacteria in their guts. Researchers from the University of Exeter and the University of Toulouse teamed up to determine how increased temperatures affected microorganism diversity in the guts of common lizards. When subjected to warming of 2-3°C, lizard’s microorganism gut diversity decreased substantially, which researchers also found affected their survival. Bacteria play a crucial role in digestion, and in the context of climate change, researchers highlighted that this decreased diversity could have major impacts on lizards and other cold-blooded animals in the future.
Squid are thriving while fish decline
Zoë A. Doubleday, Thomas A.A. Prowse, Alexander Arkhipkin, Graham J. Pierce, Jayson Semmens, Michael Steer, Stephen C. Leporati, Sílvia Lourenço, Antoni Quetglas, Warwick Sauer, Bronwyn M. Gillanders. 2016. Global proliferation of cephalopods. Current Biology (26) 10. DOI: http://dx.doi.org/10.1016/j.cub.2016.04.002
This study represents the first global-scale database of cephalopod population numbers from 1953 to 2013. The authors compiled historical catch rates for 35 species from all over the world and found consistent increases across the three cephalopod groups in all habitat types, from open ocean to tidepools. These results contrast starkly with population patterns in marine vertebrates, many of which declined by nearly half from 1970 to 2012. The authors are currently investigating potential causes of the increase in cephalopods, but suspect that climate change and overfishing may play a role. Warming oceans, while detrimental to some fish, may create beneficial growing conditions for some cephalopods, and overfishing could potentially reduce cephalopod predators.
Contrasting changes in the abundance and diversity of North American bird assemblages from 1971 to 2010
Schipper, A. M., Belmaker, J., de Miranda, M. D., Navarro, L. M., Böhning-Gaese, K., Costello, M. J., Dornelas, M., Foppen, R., Hortal, J., Huijbregts, M. A. J., Martín-López, B., Pettorelli, N., Queiroz, C., Rossberg, A. G., Santini, L., Schiffers, K., Steinmann, Z. J. N., Visconti, P., Rondinini, C. and Pereira, H. M. 2016. Contrasting changes in the abundance and diversity of North American bird assemblages from 1971 to 2010. Glob Change Biol, 22: 3948–3959. doi:10.1111/gcb.13292
An international team of scientists recently published a multidimensional analysis of the changes in abundance and biodiversity of North American bird populations. The team quantified and compared changes in abundance and three types of diversity (taxonomic, functional and phylogenetic) from 1971 to 2010, subsequently filling a void of research on the simultaneous impacts of multiple biodiversity dimensions. Data for this study came from roadside monitoring data of the North American Breeding Bird Survey which provided 5-year average abundance records of 519 species for 768 monitoring routes. The team also examined differences in biodiversity metrics among 4 subgroups based in breeding habitat affinity (grassland, woodland, wetland, and shrubland breeders). The study found that the majority of biodiversity metrics increased or stayed the same, in contrast to the total abundance pronounced decline. These contrasting changes highlight the importance of taking a multifaceted approach to measuring biodiversity change.
More warm-dwelling animals and plants as a result of climate change
Diana E. Bowler et al. 2017. Cross-realm assessment of climate change impacts on species’ abundance trends. Nature Ecology & Evolution; 1 (3): 0067 DOI: 10.1038/s41559-016-0067
A massive comprehensive study of the long-term effect of increasing temperature on species population size has been published in Nature Ecology and Evolution. The study examined population trends of approximately 1,000 species from 22 local/regional communities since 1980. The research team consisted of 27 institutions spanning scientific institutions, state authorities, non-governmental organizations, and citizen science groups. Species examined ranged from birds and butterflies, to terrestrial, freshwater and marine communities. Every species was first identified for whether they prefer warm or cool temperatures, and then assessed for changes in population size. The study observed a positive relationship between temperature preference and population size in terrestrial communities, meaning warm-dwelling species showed a larger increase in population size than cold-dwelling species. The strongest evidence was found in the most mobile species, such a birds, butterflies and terrestrial invertebrates. Results from the aquatic communities were not significant, however similar positive trend in marine fish was identified. The findings from the study confirmed that changes in ambient temperature directly impact the population size of species.
Recruitment limitation of long-lived conifers and climate change responses
Kroiss, S. J., & HilleRisLambers, J. (2015). Recruitment limitation of long-lived conifers: implications for climate change responses. Ecology, 96(5), 1286-1297.
A new study addresses the question of how seed availability and suitable germination microsites will limit tree species’ ability to shift their ranges in response to climate change. University of Washington scientists Steve Kroiss and Janneke HilleRisLambers assessed seed availability and the factors influencing germination for six conifer species across a large environmental gradient encompassing the species’ elevational ranges. Specifically, the study examined four factors: how parent-tree abundance influences annual seed availability, how seed limitation varies across species’ ranges, how climatic and biotic factors affect germination, and how seed and suitable microsite availability covary annually within and among species. The study found that seed availability decreased toward the upper edge of species’ range, and the researchers concluded that this outcome would lead to a lagged expansion in range. The study also found that microsite limitation varied strongly between low-elevation and treeline species due to varying responses to snowpack duration. Kroiss and HilleRisLambers ultimately conclude that the difference in species’ responses to seed and microsite limitation could lead to complex range shift dynamics.
Bull Trout and Climate Vulnerability
USGS aquatic ecologist, Jason Dunham, recently completed the final report on a Northwest Climate Science Center- funded study to determine how climate-related threats will influence bull trout across their southern range in Oregon, Washington, Idaho, Montana, and Nevada. Dunham and his collaborators used stream temperatures predictions to map coldwater “patches” suitable for bull trout spawning and early rearing. Larger patches of cold water with extremely cold - below 10 degrees Celsius - temperatures in summer, fewer floods in winter, and low human influence were much more likely to support the species. This work identified dozens of places where bull trout may exist, but have not yet been detected, as well as other places where bull trout may be at high risk of local extinction. Future work will focus on completing analyses across the remainder of the species’ range.
Responses of high-altitude graminoids and soil fungi to 20 years of experimental warming
Rudgers, Jennifer A., Stephanie N. Kivlin, Kenneth D. Whitney, Mary V. Price, Nickolas M. Waser, and John Harte. 2014. Responses of high-altitude graminoids and soil fungi to 20 years of experimental warming. Ecology 95:1918–1928. http://dx.doi.org/10.1890/13-1454.1
Researchers show that 20 years of experimental warming has changed the species composition of graminoid (grass and sedge) assemblages in a subalpine meadow of the Rocky Mountains, USA, by increasing the frequency of sedges and reducing the frequency of grasses. The results demonstrate that lumping grasses and sedges when characterizing plant community responses can mask significant shifts in the responses of primary producers, and their symbiotic fungi, to climate change.
The Messengers: What birds tell us about climate change
“The Messengers: What birds tell us about threats from climate change and solutions for nature and people” is a newly released global synthesis of peer-reviewed studies relating our knowledge of current threats to bird populations to the global projected impacts of climate change. In addition, the assessment contains a collection of nature-based solutions, including those led by BirdLife International Partners around the world. The solutions are examples of the kind of ecosystems-based adaptation and mitigation necessary to curtail the threat of climate change.
Land management trumps the effects of climate change and elevated CO2 on grassland functioning
Aurélie Thébault, Pierre Mariotte, Christopher J. Lortie and Andrew S. MacDougall Journal of Ecology Volume 102, Issue 4, pages 896–904, July 2014, DOI: 10.1111/1365-2745.12236
A meta-analysis is used here to examine drivers at both scales primarily targeting services provided by grasslands relating to plant productivity (above- and below-ground biomass) and soil processes (nutrients and soil respiration) in 38 manipulative experiments published in the last decade. The authors specifically target effects of (i) single and combined land management practices (LMs), (ii) single and combined factors relating to broad-scale climate change and elevated CO2, and (iii) combined management practices and changes to climate and CO2. Collectively, this examines the general efficacy of global change models in predicting changes to grassland functioning. The authors found that combinations of management practices had approximately double the explanatory power for variation in grassland services compared with individual or interactive effects of factors associated with climate change and CO2. Although this work confirms how climate change and CO2 can affect many ecosystem-based functional attributes, it suggests that combinations of land management practices remain the dominant set of factors in determining the performance of grassland plant communities. Land management may thus be critical for influencing projected responses to future climate change and elevated CO2 in models of grassland function at least for factors relating to primary production.
Elevation-Dependent Warming in Mountain Regions of the World
N. Pepin, R. S. Bradley, H. F. Diaz, M. Baraer, E. B. Caceres, N. Forsythe, H. Fowler, G. Greenwood, M. Z. Hashmi, X. D. Liu, J. R. Miller, L. Ning, A. Ohmura, E. Palazzi, I. Rangwala, W. Schöner, I. Severskiy, M. Shahgedanova, M. B. Wang, S. N. Williamson, D. Q. Yang. Elevation-dependent warming in mountain regions of the world. Nature Climate Change, 2015; 5 (5): 424 DOI: http://dx.doi.org/10.1038/nclimate2563
There is growing evidence that the rate of warming is amplified with elevation, such that high-mountain environments experience more rapid changes in temperature than environments at lower elevations. Elevation-dependent warming (EDW) can accelerate the rate of change in mountain ecosystems, cryospheric systems, hydrological regimes and biodiversity. Authors of the paper reviewed important mechanisms that contribute towards EDW: snow albedo and surface-based feedbacks; water vapor changes and latent heat release; surface water vapour and radiative flux changes; surface heat loss and temperature change; and aerosols. All lead to enhanced warming with elevation (or at a critical elevation), and it is believed that combinations of these mechanisms may account for contrasting regional patterns of EDW. The authors discuss future needs to increase knowledge of mountain temperature trends and their controlling mechanisms through improved observations, satellite-based remote sensing and model simulations.
Change is coming to the northern oceans
Anne B. Hollowed and Svein Sundby, Science 6 June 2014: 344 (6188), 1084-1085. [DOI:10.1126/science.1251166]
The cold-temperate regions of the North Pacific and North Atlantic oceans, from about 40°N latitude to the Arctic fronts, support large and productive fisheries (1), particularly in the northernmost regions: the Bering Sea in the Pacific and the Barents Sea in the Atlantic. The two main near-bottom fish species in the Bering and Barents seas are walleye pollock (Gadus chalcogrammus) and Atlantic cod (G. morhua), respectively. In the past decade, the two species have responded differently to ocean warming. These response patterns appear to be linked to a complex suite of climatic and oceanic processes that may portend future responses to warming ocean conditions.
Wildlife density data better predicts conservation success
A recent study published in the journal Conservation Biology makes a case for using more robust data sets in order to better protect birds, plants, and animals. The concept is fairly simple, but relies on scientists sharing data across studies. Presence/ absence data is now the type of data most commonly used in conservation planning, but including data on species richness could improve the ability of scientists and managers to prioritize efforts. The authors of this study encouraged partners to make their bird observation data accessible through the Avian Knowledge Network leading to the addition of over 900,000 new bird observations from 23 different studies. They then combined the information with bird data in the California Avian Data Center and developed species distribution and density models covering coastal Northern California, Oregon and Washington for 26 species of land birds representing four different habitat types. They used both the presence/absence and density models to map conservation priorities and compared the estimated population size of each species protected using both approaches. The prioritizations based on count data protected more individuals of each species than the prioritizations based on presence/absence data in the areas of highest conservation priority.
Forecasting climate change's effects on biodiversity hindered by lack of data
M. C. Urban, G. Bocedi, A. P. Hendry, J.- B. Mihoub, G. Peer, A. Singer, J. R. Bridle, L. G. Crozier, L. De Meester, W. Godsoe, A. Gonzalez, J. J. Hellmann, R. D. Holt, A. Huth, K. Johst, C. B. Krug, P. W. Leadley, S. C. F. Palmer, J. H. Pantel, A. Schmitz, P. A. Zollner, J. M. J. Travis. Improving the forecast for biodiversity under climate change. Science, 2016; 353 (6304): aad8466 DOI: 10.1126/science.aad8466
A recently published article in Science described and prioritized the critical biological information that is currently lacking from projections of species’ responses to climate change. Species-specific details such as how animals and plants spread during their lifetime and how they evolve in response to changes in the environment are understudied and not well known for most species on Earth. This paper serves as a “call to arms,” stressing the need to refocus our research attention toward understanding such biological details. The authors identified six mechanisms that influence animal response to climate change: physiology, demography, evolution, species interaction, movement, and land-use changes. The team produced many proposals on how to collect such data in order to improve current models and build what they described as a globally coordinated effort to fill data gaps and advance our understanding of climate change impacts.
Some whales are benefiting from climate change
According to a recent article from the National Geographic, whales are benefitting from climate-induced declines in sea ice. Humpback whales have been found feeding in waters off of the Western Antarctic Peninsula and the Arctic Ocean for months longer than their typical migration pattern. Rather than migrating toward tropical waters in the wintertime, these whales have lingered in the polar seas due to earlier plankton bloom onsets that lead to productive waters. Scientists from OSU have also observed humpbacks singing in Antarctic waters, indicating that they have begun breeding before migrating. The article also discussed the growing number of blue whales in the Southern Ocean and described the natural iron fertilization that is occurring because of this population increase. All of these cases suggest positive short-term impacts of climate change on whale populations, however the article also emphasized the potential long-term problems for whales. Consequences include possible feeding-time overlap between migrating whales (humpback and fin whales) and non-migrating whales (bowheads) causing atypical species competition, increased anthropogenic effects on these oceans due to ice-free ship passage (ship traffic, commercial fishing, oil spills, etc.), and the decline of organisms that whales feed on due to ocean acidification (i.e. krill).
Improving vulnerability assessments by understanding species adaptive capacity
Beever EA, O’Leary J, Mengelt C, West JM, Julius S, Green N, Magness D, Petes L, Stein B, Nicotra AB, Hellmann JJ, Robertson AL, Staudinger MD, Rosenberg AA, Babij E, Brennan J, Schuurman GW, Hofmann GE (2015). Improving conservation outcomes with a new paradigm for understanding species’ fundamental and realized adaptive capacity. Conservation Letters. doi: 10.1111/conl.12190
A new study has been published in Conservation Letters that examines the ability for species to adapt to climate change. The study was a collaborative effort between the USGS, Massachusetts Division of Fisheries and Wildlife, the National Research Council, EPA, Fish and Wildlife Service, NOAA, NPS and various universities and nonprofits. Characterizing the vulnerability of a given species to climate change depends on the sensitivity of the species and the ability of the species to accommodate climate-induced changes through adaptive capacity. This includes various coping mechanisms, such as changes in behavior, shifting geographical range and distribution, and genetic evolution. The study found that adaptive capacity is often omitted in vulnerability assessments or confused with sensitivity, yet it is critical to understand how species will respond to climate change to improve decision-making on natural resources and conservation. By not including adaptive capacity, studies do not sufficiently differentiate between which species are most at risk due to climate change.
Bird Carcasses Along Pacific Shore Baffle Biologists
Thousands of carcasses of Cassin’s auklets have been washing ashore over the last few months from northern California to Washington. The University of Washington’s Coastal Observation and Seabird Survey Team has discovered more than 1,200 carcasses since the beginning of fall. The majority of the birds have starved to death, ruling out the possibility of death from an oil spill or a toxic reaction to food. One proposed explanation is that the birds are starving as a result of an extremely successful breeding season last year. Almost every breeding pair laid an egg, and as the young migrate south for the winter they may not all be consuming sufficient food levels necessary for survival.
Wolf Numbers in Oregon Grow, but Uncertain Future Looms
The release the Oregon Department of Fish and Wildlife (ODFW) annual wolf report provides a snapshot of the gray wolf in Oregon. The report pointed out that at least 77 wolves currently live in Oregon, that 26 of them are pups younger than one year, and that the numbers in the Cascade Range jumped to seven from just one previously. The question now will be whether Oregon wolves continue to receive protection. All gray wolves in Oregon are listed under the Oregon Endangered Species Act (ESA) and all wolves west of Oregon Highways 395/78/95 are federally protected. However, reaching the mark of eight breeding pairs — and four breeding pairs for three consecutive years — took ODFW to Phase II of its management plan in Eastern Oregon. Phase II lowered the bar for considering lethal action against wolves that kill or injure livestock.
Taking stock of the assisted migration debate
Hewitt, N., Klenk, N, Smith, A.L., Bazely, D.R., Yan, N., Wood, S., MacLellan, J.I., Lipsig-Mumme, C., Henriques, I. 2011. Taking stock of the assisted migration debate. Biological Conservation. DOI: 10.1016/j.biocon.2011.04.031
A study from 2011 evaluates the academic and policy conversations around assisted migration for species most at risk from climate change impacts. Assisted migration involves the intentional relocation of species outside of their historic ranges of migration in order to mitigate losses of biodiversity that have already occurred or are anticipated to occur. The authors conducted a meta-analysis of the literature on assisted migration and found a general lack of biophysical research on the topic. For the debate to be well informed, or for proposed policies to be actionable, there must be a sufficient number of case studies and more general scientific studies that look at the potential impacts of migration on species behavior and biodiversity. The authors recommended further research as well as more extensive academic and policy conversations on the topic.
Managing climate change refugia to protect wildlife
Morelli, T.L., Daly, C., Dobrowski, S.Z., Dulen, D.M., Ebersole, J.L., Jackson, S.T., Lundquist, J.D., Millar, C.I., Maher, S.P., Monahan, W.B., Nydick, K.R., Redmond, K.T., Sawyer, S.C., Stock, S., & Beissinger, S.R. Managing Climate Change Refugia for Climate Adaptation. PLOS ONE, 2016; 11 (8): e0159909 DOI: 10.1371/journal.pone.0159909
A large group of resource managers and scientists from various Climate Science Centers have collaborated to better understand how to manage climate change refugia, or specific landscapes that are more resilient and climate-stable for their existing ecology. Toni Morelli, a USGS research ecologist with the Northwest Climate Science Center, and colleagues outlined steps, challenges, and current opportunities for managing refugia, including specific examples like freshwater refugia for cold-water-dependent species, and refugia for more mobile animals such as wolverines. While the authors acknowledge that climate change refugia will likely dissipate in the long-term as temperatures continue to warm, they also emphasize the need to take advantage of these natural short-term climate buffers as part of larger management strategies.
Grouse Rider Won’t Affect Conservation Plans
Interior Secretary Sally Jewell told governors of western states that congressional legislation which could delay implementation of an Endangered Species Act listing decision on the greater sage grouse will not impact efforts to protect the bird. She went on to say that the legislation should not deter states from pushing forward with programs to protect and restore grouse habitat. In letters written to Colorado and Wyoming governors Jewell stated, “the rider does not supersede the court-mandated Sept. 30 deadline for Fish and Wildlife to decide whether to propose listing the bird for ESA protection.”
Biodiversity Critical to Maintaining Healthy Ecosystems
Grace, J. B., Anderson, T. M., Seabloom, E. W., Borer, E. T., Adler, P. B., Harpole, W. S., Smith, M. D. (2016). Integrative modelling reveals mechanisms linking productivity and plant species richness. Nature, 529(7586), 390–393. Retrieved from http://dx.doi.org/10.1038/nature16524
Researchers from the USGS recently published a new study that assessed the link between species richness and ecosystem productivity. Using a new integrative model and data from over 1,000 different grasslands around the world, the scientists were able to detect underlying trends that clearly linked productivity to species richness, something that bivariate models could not do. The authors concluded their study by emphasizing the importance of using integrative models to advance our understanding of the mechanisms driving ecosystem productivity. Many processes were identified using the integrative model that contradicted present understanding of ecosystem productivity. The significance of the effects of richness on productivity, the persistence of competition in ecosystems regardless of productivity, and the effects of macroecolocical gradients on local richness were among the mechanisms made visible through the use of this new model.
Recruitment Limitation of Long-Lived Conifers: Implications for Climate Change Responses
Kroiss, S. J., and J. HilleRisLambers. 2015. Recruitment limitation of long-lived conifers: implications for climate change responses. Ecology 96:1286-1297. http://dx.doi.org/10.1890/14-0595.1
ss and HilleRisLambers from the University of Washington recently published a study in Ecology that evaluated recruitment limitation of long-lived conifers forest ecosystems of Mount Rainier National Park, located in the western Cascade Range in Washington. Seed availability and suitable microsites for germination are likely to severely constrain the responses of plant species to climate change, especially at and beyond range edges. For example, range shifts may be slow if seed availability is low at range edges due to low parent-tree abundance or reduced fecundity. Even when seeds are available, climatic and biotic factors may further limit the availability of suitable microsites for recruitment. Unfortunately, the importance of seed and microsite limitation during range shifts remains unknown, since few studies have examined both factors simultaneously, particularly across species' ranges. To address this issue, the researchers assessed seed availability and the factors influencing germination for six conifer species across a large environmental gradient encompassing their elevational ranges. The researchers found that seed availability declined toward species' upper range edges for most species, primarily due to low parent-tree abundance rather than declining fecundity. Range expansions are thus likely to be lagged with respect to climate change, as long generation times preclude rapid increases in tree density. In all, our results demonstrate that seed and microsite limitation will likely result in lagged responses to climate change but with differences among species leading to complex range shift dynamics.
How Chinook Salmon Respond to Climate Change
Mantua NJ, Crozier LG, Reed TE, Schindler DE, Waples RS (2015) Response of Chinook salmon to climate change. Nature Climate Change 5, 613-615. doi: 10.1038/nclimate2670
In response to Munoz et al. (2015), Mantua et al. argue that the Munoz et al. study over-generalized their study conclusions regarding the response to Chinook salmon to climate change. Munoz et al. studied the adaptive potential of Chinook salmon to changes in temperature and found that they could develop population-specific modes of adaptation in cardiac performance over evolutionary time scales, but found little adaptive capacity in one key area, the arrhythmic temperature. As a result, they concluded that the entire species was vulnerable to climate change. In this short piece, lead author Nathan Mantua argues that this conclusion ignores the ability for salmon to respond to climate change with changes in behavior, such as with altered migration timing. Previous studies conducted in Oregon’s Umpqua River on migration timing of Chinook salmon showed that median migration timing moved 40 days earlier in the year when spring water temperatures increased by 5 degrees Celsius. Furthermore, the authors disagree with the Munoz et al. conclusion that climate change is a direct threat to Pacific salmon populations. They argue that populations in the most degraded habitats might experience increased stress leading to extirpation, while populations in colder habitats might experience increased productivity with warming temperatures. Moreover, previously inaccessible habitats might become more favorable, such as has already occurred in Glacier Bay, Alaska. The effects of climate change will be context-dependent and sweeping conclusions with regard to the future of the species throughout the Pacific Northwest cannot be made.
Human impacts on biodiversity and resulting loss of ecosystem services
Forest Isbell, Andrew Gonzalez, Michel Loreau, Jane Cowles, Sandra Díaz, Andy Hector, Georgina M. Mace, David A. Wardle, Mary I. O’Connor, J. Emmett Duffy, Lindsay A. Turnbull, Patrick L. Thompson, Anne Larigauderie. Linking the influence and dependence of people on biodiversity across scales. Nature, 2017; 546 (7656): 65 DOI: 10.1038/nature22899
Coauthors from eight countries on four continents provide an overview of what we know and still need to learn about the impacts of habitat destruction, overhunting, the introduction of nonnative species, and other human activities on biodiversity. In addition, they summarize previous research on how biodiversity loss affects nature and the benefits nature provides –– for example, a recent study showing that reduced diversity in tree species in forests is linked to reduced wood production. Synthesizing findings of other studies, they estimate that the value humans derive from biodiversity is 10 times what every country in the world put together spends on conservation today — suggesting that additional investments in protecting species would not only reduce biodiversity loss but provide economic benefit, too. The researchers note that all is not lost, and offer specific strategies for turning the tide on biodiversity loss before it's too late.
Earlier spring onset in the western U.S.
Allstadt, A. J., Vavrus, S. J., Heglund, P. J., Pidgeon, A. M., Thogmartin, W. E., & Radeloff, V. C. (2015). Spring plant phenology and false springs in the conterminous US during the 21st century. Environmental Research Letters, 10(10), 104008.
A new study from the University of Wisconsin examines changes in the onset of spring plant growth. Earlier spring onset may cause phenological mismatches between the availability of plant resources and dependent animals. This could potentially lead to more false springs, when subsequent freezing temperatures damage new plant growth. The authors of this study used the extended spring indices to project changes in spring onset, and predicted false springs through 2100 in the conterminous United States (US) using downscaled climate projections from the Coupled Model Intercomparison Project 5 (CMIP5) ensemble. The median shift in spring onset was 23 days earlier in the Representative Concentration Pathway (RCP) 8.5 scenario with particularly large shifts in the Western US and the Great Plains. Spatial variation in phenology was due to the influence of short-term temperature changes around the time of spring onset versus season-long accumulation of warm temperatures. False spring risk increased in the Great Plains and portions of the Midwest, but remained constant or decreased elsewhere. This study concludes that global climate change may have complex and spatially variable effects on spring onset and false springs, making local predictions of change difficult.
Warm-water years are tough on juvenile salmon
Daly, E.A. and Brodeur, R.D. 2015. Warming Ocean Conditions Relate to Increased Trophic Requirements of Threatened and Endangered Salmon. PloS one, 10(12).
A recently published study conducted by researchers from Oregon State University and NOAA examines the effect of water temperature on Chinook salmon foraging habits and overall health. The study evaluated 19 years (1981-1985, 1998-2011) of juvenile salmon surveys and discovered that when water is warmer than average, young salmon consume 30 percent more food than during cold-water regimes. Despite this higher consumption, the salmon studied under warm water conditions were found to be smaller and skinnier. This is likely due to the fact that warmer water requires salmon to eat more in order to keep their metabolic rate up, which causes them to work harder for food. In addition, the food is less nutritious due to the lack of lipid-rich prey available during warm water conditions. Warmer water conditions have been occurring in the waters off the Pacific Northwest for the past two years due to “The Blob”. The researchers of this study conclude by stressing that as warm water persists, the ability for young salmon to find enough food will drastically decline.
Audubon Society's Birds and Climate Change Report: 314 species on the brink
Audubon scientists have used hundreds of thousands of citizen-science observations spanning three decades and sophisticated climate models to predict how 588 species of birds in the U.S. and Canada will react to climate change. Audubon's work defines the climate conditions birds need to survive, then maps where those conditions will be found in the future as the Earth's climate responds to increased greenhouse gases. Audubon's model predicts that 314 North American bird species face the risk of extinction by the year 2100. The Society has separated those 314 species into two groups: (1) Climate Threatened, 188 species that may lose over 50% of their current ranges by 2080 and (2) Climate Endangered, 126 species that may lose over 50% of their current ranges by 2050. An innovative feature of the Audubon website is an interactive, animated map for each of the 314 species showing where a particular species is likely to find suitable climate conditions for survival at three future time thresholds: 2020, 2050, and 2080. Audubon plans to expand the map feature in the future to include all 588 species.
The subtle role of climate change on population genetic structure in Canada lynx
Row, J. R., Wilson, P. J., Gomez, C., Koen, E. L., Bowman, J., Thornton, D. and Murray, D. L. (2014), The subtle role of climate change on population genetic structure in Canada lynx. Global Change Biology, 20: 2076–2086. doi: 10.1111/gcb.12526
This research shows that current genetic variability of Canada lynx is strongly correlated with a winter climate gradient (i.e. increasing snow depth and winter precipitation from west-to-east) across the Pacific-North American (PNO) to North Atlantic Oscillation (NAO) climatic systems. This relationship was stronger than isolation by distance and not explained by landscape variables or changes in abundance. Thus, these patterns suggest that individuals restricted dispersal across the climate boundary, likely in the absence of changes in habitat quality. We propose habitat imprinting on snow conditions as one possible explanation for this unusual phenomenon. Coupling historical climate data with future projections, we also found increasingly diverging snow conditions between the two climate systems. Based on genetic simulations using projected climate data (2041–2070), we predicted that this divergence could lead to a threefold increase in genetic differentiation, potentially leading to isolated east–west populations of lynx in North America. Our results imply that subtle genetic structure can be governed by current climate and that substantive genetic differentiation and related ecological divergence may arise from changing climate patterns.
Precipitation, not warming temperatures, may be key in bird adaptation to climate change
Illán, J. G., Thomas, C. D., Jones, J. A., Wong, W.-K., Shirley, S. M. and Betts, M. G. (2014), Precipitation and winter temperature predict long-term range-scale abundance changes in Western North American birds. Global Change Biology. doi: 10.1111/gcb.12642
A new empirically-based model analyzing how birds in western North America will respond to climate change suggests that for most species, regional warming is not as likely to influence population trends as will precipitation changes. Several past studies have found that temperature increases can push some animal species – including birds – into higher latitudes or higher elevations. Few studies, however, have tackled the role that changes in precipitation may cause. This analysis finds that for many species, it is precipitation that most affects the long-term survival of many bird species due to associated changes plant growth, soil moisture, water storage and insect abundance and distributions. The researchers examined long-term data on bird distributions and abundance covering five states in the western United States, and in the Canadian province of British Columbia, testing statistical models to predict temporal changes in population of 132 bird species over a 32-year period. They analyzed the impacts of temperature and precipitation on bird distributions at the beginning of the study period (the 1970s) and then tested how well the predictions performed against actual population trends over the ensuing 30 years.
Is adaptation to climate change really constrained in niche specialists?
Belinda van Heerwaarden and Carla M. Sgrò, Proc. R. Soc. B 7 September 2014 vol. 281 no. 1790 20140396, Published online 23 July 2014 doi: 10.1098/rspb.2014.0396
Species with restricted distributions make up the vast majority of biodiversity. Recent evidence suggests that Drosophila species with restricted tropical distributions lack genetic variation in the key trait of desiccation resistance. It has therefore been predicted that tropically restricted species will be limited in their evolutionary response to future climatic changes and will face higher risks of extinction. However, these assessments have been made using extreme levels of desiccation stress (less than 10% relative humidity (RH)) that extend well beyond the changes projected for the wet tropics under climate change scenarios over the next 30 years. Here, we show that significant evolutionary responses to less extreme (35% RH) but more ecologically realistic levels of climatic change and desiccation stress are in fact possible in two species of rainforest restricted Drosophila. Evolution may indeed be an important means by which sensitive rainforest-restricted species are able to mitigate the effects of climate change.
'Robomussels' used to monitor climate change
Helmuth, B. et al. 2016. Long-term, high frequency in situ measurements of intertidal mussel bed temperatures using biomimetic sensors. Scientific Data, 3: 160087 DOI:10.1038/sdata.2016.87
For the past two decades, Northeastern University scientist Brian Helmuth and his colleagues have been collecting field observations of the internal temperature of mussel beds using small, mussel-like biomimetic sensors. Their database was used to link mussel bed temperature to the physiological impact of global climate change on mussels. Results have been recently published in the journal Scientific Data, and shown that mussels act as a barometer of climate change, in the sense that they rely on external sources of heat to regulate their own body temperature. Additionally, the database has allowed scientists to detect areas of unusual warming, high erosion, or acidification, and enabled managers, policymakers and researchers to develop strategies that could mitigate these stressors.
Climate Change Impact on American Pika using Improved Species Distribution Models
Schwalm, D., Epps, C. W., Rodhouse, T. J., Monahan, W. B., Castillo, J. A., Ray, C. and Jeffress, M. R. (2016), Habitat availability and gene flow influence diverging local population trajectories under scenarios of climate change: a place-based approach. Glob Change Biol. doi:10.1111/gcb.13189
Species distribution models (SDMs) are used to project the impact of climate change on species’ ecological niches, but often paint an overly simplistic picture that is limited to climate-occupancy interactions. In this new study, Oregon State University scientists used more complex modeling to research the impact of climate change on the American pika. The study incorporated climate, gene flow, habitat configuration, and microhabitat complexity to build separate SDMs for pika populations inhabiting eight U.S. National Park Service units, a distribution that represents pika variety across the U.S. The results displayed highly variable occupancy patterns across the western U.S., suggesting important local-scale differences in the realized niche of the American pika. The study also found that habitat composition and connectivity were among the most influential variables in predicting pika occupancy for all study areas. This is an important result because SDMs rarely include these two variables, stressing the importance of including fine-scale factors when assessing current and future climate impacts on species’ distributions.
Using Citizen-Science Data to Identify Local Hotspots of Seabird Occurrence
Ward EJ, Marshall KN, Ross T, Sedgley A, Hass T, Pearson SF, Joyce G, Hamel NJ, Hodum PJ, Faucett R. 2015. Using citizen-science data to identify local hotspots of seabird occurrence. PeerJ. http://dx.doi.org/10.7717/peerj.704
Seabirds have been used as indicators of ecosystem processes such as climate change and human activity in near-shore ecosystems around the world. A recent study published in PeerJ tracked the occurrence of 18 seabird species at 62 sites around Puget Sound. Despite historic declines of seabirds in the region, results from this study are optimistic, suggesting increases in probabilities of occurrence for 14 of the 18 species studied (including cormorants, loons, rhinoceros auklets, and harlequin ducks). Additionally, the study documented local hotspots for certain species, which may indicate important habitat or prey the seabirds depend on.
Increasing Hydrologic Variability Threatens Depleted Anadromous Fish Populations
Ward, E.J., Anderson J.H., Beechie, T.J., Pess, G.R., Ford, M.J. 2015. Increasing hydrologic variability threatens depleted anadromous fish populations. Global Change Biology doi: http://dx.doi.org/10.1111/gcb.12847
Predicting effects of climate change on species and ecosystems depends on understanding responses to shifts in means (such as trends in global temperatures), but also shifts in climate variability. Researchers from NOAA and Washington Department of Fish and Wildlife evaluated potential responses of anadromous fish populations to an increasingly variable environment. Researchers used hierarchical analysis of 21 Chinook salmon populations from the Pacific Northwest to examine support for changes in river flows and flow variability on population growth. Results suggest that more than half of the rivers analyzed have already experienced significant increases in flow variability over the last 60 years, and this study shows that this increase in variability in freshwater flows has a more negative effect than any other climate signal included in the model. Climate change models predict that the Puget Sound region of Washington will experience warmer winters and more variable flows, which may limit the ability of these Chinook salmon populations to recover.
A systematic review of ecological attributes that confer resilience to climate change in environmental restoration
Timpane-Padgham BL, Beechie T, Klinger T. 2017. A systematic review of ecological attributes that confer resilience to climate change in environmental restoration. PLoS ONE 12(3): e0173812. https://doi.org/10.1371/journal.pone.0173812
Researchers from the University of Washington and NOAA’s Northwest Fisheries Science Center utilized ecological resilience literature to identify 45 specific attributes that are explicitly related to climate change. They classified them at different scales and identified which scales and approaches are more appropriate for different restoration and monitoring projects. By summarizing these relationships in a decision support table, researchers illustrate how these classifications can be used to prioritize climate change resilience information in specific restoration plans. They propose that identifying sources of ecological resilience is a critical step in restoring ecosystems in a changing climate.
Feds release plan for recovering Northwest fish species
Federal authorities have released their final recovery plan for a fish species that teetered on the brink of extinction in the early 1990s in one of the Pacific Northwest’s major rivers. The National Oceanic and Atmospheric Administration released the plan on June 8th with the goal of creating a self-sustaining population of Snake River sockeye salmon over the next 50 to 100 years.
Plants can run but they can’t hide from warming
Williams, J.L., Kendall, B.E., Levine, J.M. 2016. Rapid evolution accelerates plant population spread in fragmented experimental landscapes. Science 353 (6298): 482-485 DOI: 10.1126/science.aaf6268.
A recently published study from the University of British Columbia examined the significance of evolution on plant species migration in varyingly patchy landscapes. Plant ecologist Jennifer Williams and her colleagues designed a lab experiment measuring six generations of seed dispersal of the plant species Arabidopsis thaliana across landscapes with varying patchiness. The authors were able to measure the impact of evolution on seed dispersal by precluding natural selection within half the experimental seeds. The “no evolution” experimental group was cultivated by removing newly germinated seedlings and replacing them with individuals of the same genotype as the parent generation. After six generations, the study found that evolving species spread 11% farther than non-evolving species in non-patchy (continuous) landscapes, and 200% farther than non-evolving species in the most fragmented environments. The results of this study show the significance of evolution as a driving mechanism in plants’ ability to migrate in response to climate change.
Native Olympia oysters more resilient to ocean acidification
Waldbusser, G. G., Gray, M. W., Hales, B., Langdon, C. J., Haley, B. A., Gimenez, I., Smith, S. R., Brunner, E. L. and Hutchinson, G. 2016. Slow shell building, a possible trait for resistance to the effects of acute ocean acidification. Journal of Limnology and Oceanography. doi:10.1002/lno.10348
In this recently published study, scientists from Oregon State University found support for the “kinetic-energetic hypothesis,” which posits that rapid shell growth (calcification), limited energy reserves, and more exposed calcification surfaces are traits that make mollusks more vulnerable to ocean acidification. The Olympia oyster exhibits slow embryo development relative to broadcast spawning mollusks and so presents an appropriate species to test the kinetic-energetic hypothesis. In this study, George Waldbusser and colleagues examined the success of pre-developed Olympia oysters in various pH conditions. The study found that the species showed no acute negative response to acidification treatments, thus supporting the current hypothesis. According to an interview with Waldbusser, it is possible that farmers could breed the slow-growing trait as a way of increasing the resilience of commercial species, like the Pacific oyster.
Natural Resource Assessment of North Cascades National Park Service Complex
Hoffman, Jr., R., Woodward, A., Haggerty, P., Jenkins, K.J., Griffin, P.C., Adams, M.J., Hagar, J., Cummings, T., Duriscoe, D., Kopper, K., Riedel, J., Marin, L., Mauger, G.S., Bumbaco, K., Littell, J.S., 2015, North Cascades National Park Service Complex- Natural Resource condition Assessment: National Park Service NPS/NOCA/NRR—2015/901, p. 390.
Researchers from the USGS and other organizations have completed a Natural Resource Condition Assessment (NRCA) for the North Cascades National Park Service Complex (NOCA). The report is an evaluation of current conditions for a subset of NOCA natural resources and resource indicators in relation to reference conditions and values. Additionally, the report describes influences and trends in resource conditions, highlights emerging issues, and identifies critical information requirements and data gaps. The report highlights 14 key indicators: air quality, stream and lake water quality, vegetation, wildlife (including amphibians, landbirds, fish, and mammals), glaciers, soundscapes, and night skies. The data collected for the report spans decades and will assist park managers in their near- and long-term efforts to describe the park’s resource conditions and desired management targets.
Relative Sensitivity to Climate Change of Species in Northwestern North America
Case MJ, Lawler JJ, Tomasevic JA (2015) Relative sensitivity to climate change of species in northwestern North America. Biological Conservation 187:127-133. http://dx.doi.org/ 10.1016/j.biocon.2015.04.013
Michael Case and Joshua Lawler from University of Washington recently published a paper titled “Relative sensitivity to climate change of species in northwestern North America” in the journal Biological Conservation. The authors used a combination of scientific literature and expert knowledge to assess the relative sensitivity to climate change of 195 plant and animal species in the northwestern North America. Results show that although there were highly sensitive species in each of the taxonomic groups analyzed, amphibians and reptiles were, as a group, estimated to be the most sensitive to climate change. Results also indicate that many species will be sensitive to climate change largely because they depend on habitats that will likely be significantly altered as climates change. Although to date, many climate impact assessments for species have focused on projecting range shifts, quantifying physiological limits, and assessing phenological shifts, in light of the results, a renewed emphasis on the collection of basic natural history data could go a long way toward improving our ability to anticipate future climate impacts. The results highlight the potential for basic information about climate-change sensitivity to facilitate the prioritization of management actions and research needs in the face of limited budgets.
Climate Registry for the Assessment of Vulnerability
The USGS National Climate Change and Wildlife Science Center has worked with the non-profit EcoAdapt and other partners to develop a tool called the Climate Registry for the Assessment of Vulnerability (CRAVe ). This tool will house metadata on climate change vulnerability assessments from across the nation and will be made available for searching by the general public.
Effects of past climate change on Heermann's Gull from late Quaternary to present
Ruiz, E.A., Velarde, E. and Aguilar, A., 2017. Demographic history of Heermann's Gull (Larus heermanni) from late Quaternary to present: Effects of past climate change in the Gulf of California. The Auk, 134(2), pp.308-316.
Climate change during the late Quaternary period (LQP) was a major driver in the shaping of species distributions and abundances. Understanding of the effects of climate change on population dynamics of marine species in temperate zones is growing. However, studies on the demographic history of seabirds are rare, and there is no description of how regional climate change has affected high-trophic-level marine species such as Heermann's Gull (Larus heermanni). Authors of this study investigated whether the demographic history of Heermann's Gull reflects population change consistent with past changes in climate during the LQP. They also explored whether past changes affected the demographic history of codistributed marine organisms in a similar way. Results support a demographic expansion during the LQP for Heermann's Gulls. The authors discuss possible associations between the demographic expansion of this seabird species and large-scale ecological shifts or demographic expansions of other marine species.
Pattern of mammal dwarfing during global warming
Abigail R. D’Ambrosia, William C. Clyde, Henry C. Fricke, Philip D. Gingerich, Hemmo A. Abels. Repetitive mammalian dwarfing during ancient greenhouse warming events. Science Advances, 2017; 3 (3): e1601430 DOI: 10.1126/sciadv.1601430
A team of scientists examined the effect of Paleocene-Eocene global warming on mammalian body size. Due to the fact that smaller body size allows faster cool down, as well as increased efficiency in nutrient intake, smaller body size became favored by evolution under extreme warming. The authors quantified the relationship between mammalian body size and the intensity of warming events, and were able to identify the possible effects present anthropogenic climate change could have on this mechanism of adaptation.
A review of conservation buffer distance estimates for the Greater Sage-Grouse
Manier, D.J., Bowen, Z.H., Brooks, M.L., Casazza, M.L., Coates, P.S., Deibert, P.A., Hanser, S.E., and Johnson, D.H. 2014. Conservation buffer distance estimates for Greater Sage-Grouse—A review: U.S. Geological Survey Open-File Report 2014–1239, 14 p.doi: http://dx.doi.org/10.3133/ofr20141239
This report summarizes a collection of published scientific studies that evaluated the effects of anthropogenic activities and infrastructure on Greater Sage-Grouse populations. It is intended to serve as a reference for land managers and others who aim to establish buffer distances around sage-grouse habitats. While the report does not propose management recommendations, it does provide summaries, interpretations, and citations of management recommendations from the scientific literature. Due to inherent variation in ecosystems, habitats, and populations, there is no one-size-fits-all solution for population buffer distance. Therefore, the report presents buffer distance values for six categories of different land use or disturbance categories commonly found in land-use plants.
Climate change is already causing widespread local extinction in plant and animal species
John J. Wiens. Climate-Related Local Extinctions Are Already Widespread among Plant and Animal Species. PLOS Biology, 2016; 14 (12): e2001104 DOI: 10.1371/journal.pbio.2001104
Scientist John Wiens from the University of Arizona recently published a comprehensive report on local species extinctions that are already occurring due to climate change. Wiens used an array of range-shift studies to compile a synthesis of existing localized extinction frequencies. Out of the 976 species studied, Wiens found 47% exhibited local extinction. The highest extinction frequencies were found in tropical species, animals (compared to plants), and freshwater habitats relative to terrestrial and marine habitats.
One third of north american birds at risk of extinction due to human activity and climate change
The North American Bird Conservation Initiative’s latest “State of the Birds” report finds that more than one-third of North America’s 1,154 native bird species are at high risk of extinction due to climate change and other manmade factors. Thirty-seven percent of the continent’s bird species across 10 different habitat types need “urgent conservation action.” Forty-nine percent were identified as having moderate risk, while just 14 percent were marked as low risk. Researchers categorized bird species based on their population size, population trends, population distribution and threats to both breeding and non-breeding members of the species. The decline of bird species is most pronounced in ocean habitats, where 57 percent were identified as having a high risk of extinction and are on the organization’s “Watch List.” The authors point out that western temperate forest birds are of higher conservation concern, due to smaller ranges and populations, than eastern forest birds.
Evidence of birds adapting phenology to climate change
McDermott, M. E. and DeGroote, L. W. 2016. Long-term climate impacts on breeding bird phenology in Pennsylvania, USA. Global Change Biology, 22: 3304–3319. doi: 10.1111/gcb.13363
Molly McDermott and Lucas DeGroote from the Carnegie Museum of Natural History recently published a study examining climate-induced changes to the phenology of 21 species of passerine birds (perching birds) in Pennsylvania. The authors analyzed a 53 year-long record of reproductive timing and productivity of passerine birds from a single mist-netting station in western Pennsylvania and combined the data with long-term weather records. According to a news article from Anthropocene Magazine, some of the results from this study include: house wrens and American goldfinches bred later into the year while black-capped chickadees started much earlier, Cedar waxwings tend to thrive during warmer summers while rose-breasted grosbeaks preferred cooler temperatures, and rainy springs delayed egg-laying for indigo buntings but hastened it for Eastern phoebes.” The findings indicate that many passerine birds are adapting to climate change. The authors concluded the study with an emphasis on the importance of long-term monitoring studies.
Winners, losers among fish when landscape undergoes change
Jonathan W. Moore, Julian D. Olden. Response diversity, nonnative species, and disassembly rules buffer freshwater ecosystem processes from anthropogenic change. Global Change Biology, 2016; DOI: 10.1111/gcb.13536
Jonathan Moore from Simon Fraser University and Julian Olden from the University of Washington recently published a study in which they examined the relationship between freshwater fish ecosystems and human land development. The authors analyzed data of 533 fish species from 8,100 stream locations across the contiguous U.S. For each species, the researchers collected data on nutrient excretion in order to quantify their role in the recycling of nutrients within their freshwater ecosystem. By doing so, the study built an unprecedented national-level map of nutrient excretion by freshwater fish. The authors then analyzed species response to human land development and found a diversity of sensitivities across fish species, including a particular contrast between native and non-native fish. Through modeled projections of increased land-use change, the study showed an estimated decrease in fish nutrient excretion for 63% of the ecoregions studied, and that this loss of excretion would be 84% greater in the absence of non-native species, which seem to act as a buffer to ecosystem change.
Climate and Weather Reports and Services
An evaluation of high-resolution regional climate model simulations of snow cover
Minder, J. R., T. W. Letcher, and S. M. Skiles. 2016. An evaluation of high-resolution regional climate model simulations of snow cover and albedo over the Rocky Mountains, with implications for the simulated snow-albedo feedback, J. Geophys. Res. Atmos., 121, 9069–9088, doi:10.1002/2016JD024995.
A study recently published in the Journal of Geophysical Research evaluated the ability of high-resolution regional climate model simulations to accurately capture snow cover and surface albedo in midlatitudinal mountainous regions. Climate scientist Justin Minder from the State University of New York at Albany and his colleagues compared seven years of simulation data from the Weather Research and Forecasting model over the central Rocky Mountains to high-resolution satellite data of snow cover and albedo. The study found the simulations to exhibit important biases. One exhibited a large positive bias in surface albedo, and the other a negative bias in areal snow cover. The authors concluded that more work is required in order for regional climate models to produce confident projections of climate change over mountainous regions.
Where and when will we observe cloud changes due to climate warming?
Chepfer, H., V. Noel, D. Winker, and M. Chiriaco. 2014. Where and when will we observe cloud changes due to climate warming? Geophysical Research Letters, 41, doi: http://dx.doi.org/10.1002/2014GL061792
Models predict that cloud distribution will change in response to climate warming, however uncertainties in the satellite record are greater than the magnitude of the predicted effects. Authors of a recent publication in Geophysical Research Letters discussed the effects of climate change on cloud distribution. The researchers used satellite observations and model-simulated observations to detected changes in cloud distribution that were attributable to climate change. This study demonstrates that cloud vertical distribution is sensitive to climate change and that cloud radiative effect and total cloud cover are not robust signatures of climate change.
Climate Change may Bring Stronger Storms, Less Frequently
Laliberté, F., Zika, J., Mudryk, L., Kushner, P. J., Kjellsson, J., Döös, K. 2015. Constrained work output of the moist atmospheric heat engine in a warming climate. Science, doi: http://dx.doi.org/10.1126/science.1257103
In a new study published in the journal Science, scientists offered a new perspective on how the Earth's atmosphere acts as a heat engine, shifting heat from the sun from the tropics toward the poles. Warmer air can hold more moisture (i.e. rain, hail, or snow). Simultaneously, as the planet warms more evaporation and precipitation are projected to use more energy in the atmosphere. This energy reduction will reduce the intensity of winds around the world – leading to a future with more severe, less frequent storms.
Interactive Climate Map: Temperature, Precipitation, and Drought Outlooks
The National Oceanic and Atmospheric Administration (NOAA) along with its academic and international partners are making great strides in linking severe weather, winter storms, droughts and floods, and hurricane events to climate variability such as El Niño and La Niña, and other modes of natural climate variability. The Climate Prediction Center (CPC), working with national and international partners, is at the forefront of turning this new understanding into practical tools and useful products for predicting such events and their impacts months to seasons in advance to reduce vulnerability and exploit opportunities for beneficial impacts. Better predictions of extreme climate episodes like floods and droughts could save the United States billions of dollars in damage costs. Water, energy and transportation managers would be able to plan and avoid or mitigate these losses.
Long-term Pacific climate cycle linked to expansion of Antarctic sea ice
Summarized by Hickey, H. (2016, July 5). Long-term Pacific climate cycle linked to expansion of Antarctic sea ice. http://www.washington.edu/news/2016/07/05/long-term-pacific-climate-cycl...
Meehl, G. A., Arblaster, J. M., Bitz, C. M., Chung, C. T., & Teng, H. (2016). Antarctic sea-ice expansion between 2000 and 2014 driven by tropical Pacific decadal climate variability. Nature Geoscience 9(8), 590-595. doi:10.1038/ngeo2751
According to a paper published this week in Nature Geoscience, the trend of increasing Antarctic sea ice can be mostly explained by a natural long- term climate fluctuation. The study sought to explain why Antarctic sea ice is expanding despite climate-related global warming. The authors offered evidence that the current negative phase of the Interdecadal Pacific Oscillation, which brings cooler-than-average sea surface temperatures in the tropical eastern Pacific, has created favorable conditions for additional Antarctic sea ice growth since 2000. The ultimate impact is a deepening of a low-pressure system off the coast of Antarctica known as the Amundsen Sea Low. Winds generated on the western flank of this system blow sea ice northward, away from Antarctica, helping to enlarge the extent of sea ice coverage.
Northwest Passage clear of ice again in 2016
The Arctic Ocean experienced the fourth smallest sea ice extent in August 2016. Once again, the Northwest Passage, a ship route from the Atlantic to the Pacific Ocean through the Canadian Artic, is passable. The ship route has been roughly clear since 2006, and recently safe enough to allow for a luxury cruise (Crystal Serenity) to travel from Alaska to New York via the southern route. Due to climate change, commercial and luxury ship passage through the Canadian Arctic is expected to continue indefinitely.
New handbook on sea level rise highlights science and models for non-scientists
The US Geological Survey has published a new handbook that details models that are used to study and predict sea-level rise and how it is projected to impact coasts. It is designed for land managers, coastal planners and policy makers and explains how sea level changes are occurring. It explains models, analysis techniques and datasets available and how they are used by scientists and engineers to understand historical sea level trends and to project future rates of sea level rise and coastal impacts. The work was supported by the Southeast Climate Science Center. A copy of the handbook is available below:
Decadal modulation of global surface temperature by internal climate variability
Dai, A., J. C. Fyfe, S.-P. Xie, and X. Dai. 2015. Decadal modulation of global surface temperature by internal climate variability. Nature Climate Change 5: 555-559.
Despite a steady increase in atmospheric greenhouse gases (GHGs), global-mean surface temperature (T) has shown no discernible warming since about 2000, in sharp contrast to model simulations, which on average project strong warming. The recent slowdown in observed surface warming has been attributed to decadal cooling in the tropical Pacific, intensifying trade winds, changes in El Niño activity, increasing volcanic activity and decreasing solar irradiance. Earlier periods of arrested warming have been observed but received much less attention than the recent period, and their causes are poorly understood. Here Dai et al. analyze observed and model-simulated global T fields to quantify the contributions of internal climate variability (ICV) to decadal changes in global-mean T since 1920. They show that the Interdecadal Pacific Oscillation (IPO) has been associated with large T anomalies over both ocean and land. Combined with another leading mode of ICV, the IPO explains most of the difference between observed and model-simulated rates of decadal change in global-mean T since 1920, and particularly over the so-called ‘hiatus’ period since about 2000. They conclude that ICV, mainly through the IPO, was largely responsible for the recent slowdown, as well as for earlier slowdowns and accelerations in global-mean T since 1920, with preferred spatial patterns different from those associated with GHG-induced warming or aerosol-induced cooling. Recent history suggests that the IPO could reverse course and lead to accelerated global warming in the coming decades.
NOAA says ‘hiatus’ disappears once data corrected
The ongoing conversation as to why the planet had apparently experienced what has been termed a ‘hiatus’ or pause in global warming since just before the turn of the millennium, has received another contribution, this time with US National Oceanographic and Atmospheric Administration (NOAA) suggesting that there actually was no hiatus. Researchers with NOAA say in a new paper out this week in the journal Science that once adjustments to data are made correcting for errors, the slowdown disappears. That is, the hiatus is in fact nothing more than an artifact of inaccurate data. Instead, the research suggests that global warming may now be accelerating.
Tracking the start of the spring season across the country using Spring Leaf and Bloom Indices
The USA National Phenology Network (USA-NPN) tracks the start of the spring season across the country using models called the Spring Leaf and Bloom Indices. The Spring Leaf Index is a synthetic measure of early season events like the first appearance of tiny leaves on trees, or crocus plants emerging from the snow, based on recent temperature conditions. This model allows scientists to track the progression of spring onset across the country. In 2017, USA-NPN saw very large anomalies in the United States on the Spring Leaf Index map, where the Index was met up to three weeks earlier than what is typical (1981-2010) in the southeast and almost equally late in the Northwest.
Climate Prediction Center Releases New Report on El Nino
The Climate Prediction Center has released a new report on the El Nino Southern Oscillation. The report issues an ‘El Nino Advisory’, stating ‘El Nino conditions are present’, ‘Positive equatorial sea surface temperature (SST) anomalies continue across most of the Pacific Ocean’ and that ‘There is a greater than 90% chance that El Nino will continue through Northern Hemisphere winter 2015-16, and around an 80% chance it will last through early spring 2016.”
Groundwater depletion in California Causing Valley Land to Sink
The California Department of Water Resources released a new NASA report showing that the San Joaquin Valley is sinking at a faster rate than ever before, even up to about two inches per month in some locations. Due to the drought, groundwater is being pumped at a much higher rate, leading to record low levels of groundwater, according to Department of Water Resources Director Mark Cowin. Sinking land, which is referred to as subsidence, is not a new phenomenon in California. However, it is occurring much faster than before, which puts infrastructure at a significant risk. Land in the Tulare basin sank 13 inches in just 8 months, and one part of the Sacramento Valley is sinking at about ½ inch per month. At one location in the Delta-Mendota Canal, land sank so much that a bridge nearly touches the water there. NASA is continuously monitoring subsidence with data from the European Space Agency’s new Sentinel-1 mission. The Department of Water Resources is launching a $10 million program to help counties in California that are experiencing high stress from groundwater depletion.
NOAA Climate Connection E-Newsletter
Rainfall generates a new source of airborne organic particles
Wang, B., Harder, T. H., Kelly, S. T., Piens, D. S., China, S., Kovarik, L., Keiluweit, M. Arey, B.W., Gilles, M.K., Laskin, A. (2016). Airborne soil organic particles generated by precipitation. Nature Geoscience. doi:10.1038/ngeo2705.
Scientists from the Pacific Northwest National Laboratory and the Lawrence Berkeley National Laboratory have discovered a new source of atmospheric organic particulate that has not yet been accounted for in climate models: tiny soil particles that become airborne after a rain event. This new study quantified the effect of raindrop impaction on the generation of these atmospheric particles using experimental irrigation in the Southern Great Plains, OK. The scientists found that, after rainfall, microscopic organic particles from the soil were ejected into the air and contributed up to 60% of atmospheric particles. After studying the physical and chemical properties of these solid particles, the scientists suggested that they could play a critical role in the formation of clouds and subsequent radiative forcing. The authors emphasize the importance of including this source of airborne particle in climate models, particularly for agricultural and grassland ecosystems.
Effects of Climate Oscillations on Wind Resource Variability
Hamlington, B.D., Hamplington, P.E., Collins, S.G., Alexander, S.R., Kim, K.-Y. 2015. Effects of climate oscillations on wind resource variability in the United States. Geophysical Research Letters, 42, 1-8. http://dx.doi.org/10.1002/2014GL062370
Researchers recently published a paper in Geophysical Research Letters evaluating natural climate variations in U.S. wind resource. Using cyclostationary empirical orthogonal functions (CSEOFs) researchers assessed the variability of the wind resource on annual and interannual time scales at all locations across the U.S. This study evaluated impacts on wind resource variability from the modulated annual cycle (MAC) and the El Nino-Southern Oscillation (ENSO), and revealed variation in the wind speed of up to 30% at individual sites. The results presented in this study have important implication for predictions of wind plan power output and siting.
Soil carbon released into air might equal US emissions, triggering runaway climate change
T. W. Crowther, et al. Quantifying global soil carbon losses in response to warming. Nature, 2016; 540 (7631): 104 DOI: 10.1038/nature20150
A study led by scientists from Yale University examined the source to sink relationship of soil carbon in order to quantify its role with future warming. The team of researchers analyzed data from 49 field experiments located at various latitudes throughout the Northern Hemisphere. The higher latitudes exhibited the most significant losses of soil carbon storage. This result, when combined with future warming projections, indicates a significant positive feedback and further planetary warming. The authors concluded that, despite the uncertainty in their data, soil carbon consistently acted as a source for atmospheric carbon.
Evaluation of a regional climate modeling effort for the Western United States using a superensemble:
Sihan Li, Philip W. Mote, David E. Rupp, Dean Vickers, Roberto Mera, and Myles Allen. (2015). Evaluation of a Regional Climate Modeling Effort for the Western United States Using a Superensemble from Weather@home. Journal of Climate, Vol. 28, No. 19 : pp. 7470-7488 (doi: 10.1175/JCLI-D-14-00808.1)
A group of scientists from OSU, the Union of Concerned Scientists, and Oxford compared simulations from a regional climate model (RCM) as part of a superensemble experiment with observational data over the western United States. Overall, the means of seasonal temperature were well represented in the simulations. Additionally, the overall magnitude and spatial pattern of precipitation were well characterized, though somewhat exaggerated along the coastal mountains, Cascade Range, and Sierra Nevada. The simulations also produced regional U.S. weather patterns associated with El Niño. The superensemble simulated the observed spatial pattern of mean annual temperature more faithfully than any of the RCM–GCM pairings in the North American Regional Climate Change Assessment Program (NARCCAP), and its errors in mean annual precipitation fell within the range of errors of the NARCCAP models. Lastly, this paper provided examples of the size of an ensemble required to detect changes at the local level and demonstrated the effect of parameter perturbation on regional precipitation.
PNW Climate Outlook
This quarterly report from the Pacific Northwest Climate Impacts Research Consortium (CIRC) provides a seasonal wrap up of relevant regional issues along with an outlook for the coming season in Idaho, Oregon, Washington and Western Montana. To subscribe send an email to John Stevenson.
Projections of 21st century climate of the Columbia River Basin
Rupp, D.E., Abatzoglou, J.T. & Mote, 2016. Projections of 21st century climate of the Columbia River Basin. P.W. Clim Dyn doi:10.1007/s00382-016-3418-7
Academic director of the Northwest Climate Science Center, Philip Mote, and climate scientists, David Rupp from Oregon State University and John Abatzoglou from Idaho State University, recently published a comprehensive report of 21st century climate projections for the Columbia River Basin. Using 35 global climate model (GCM) simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5), the authors summarized projections of both temperature and precipitation changes in the Columbia River Basin. Mean annual temperature is projected to increase by 2.8 ℃ by the late 21st century with 18% more warming during summer. Projections for changes in precipitation were slightly less confident than those for temperature as not all GCMs agreed on the sign of change (positive or negative). The report, published in Climate Dynamics, additionally addressed questions regarding the seasonal and interannual variability of climate projections.
Threat to future global food security from climate change and ozone air pollution
Tai et al., Threat to future global food security from climate change and ozone air pollution, Nature Clim. Change, 2014/07/27 advance online publication, http://dx.doi.org/10.1038/nclimate2317
This study shows that warming reduces global crop production by >10% by 2050 with a potential to substantially worsen global malnutrition in all scenarios considered. Ozone trends either exacerbate or offset a substantial fraction of climate impacts depending on the scenario, suggesting the importance of air quality management in agricultural planning. Furthermore, we find that depending on region some crops are primarily sensitive to either ozone (for example, wheat) or heat (for example, maize) alone, providing a measure of relative benefits of climate adaptation versus ozone regulation for food security in different regions.
Superensemble regional climate modeling for the western U.S.
Mote, P. W., Allen, M. R., Jones, R. G., Li, S., Mera, R., Rupp, D. E., & Vickers, D. (2015). Superensemble regional climate modeling for the western US. Bulletin of the American Meteorological Society, (2015).
Computing resources donated by volunteers have generated the first superensemble of regional climate model results, in which the Hadley regional model HadRM3P and atmospheric global model HadAM3P were implemented for the western US at 25km resolution. Over 136,000 valid and complete one-year runs have been generated to date: about 126,000 for 1960-2009 using observed sea surface temperatures (SSTs) and 10,000 for 2030-2049 using projected SSTs from a global model simulation. Ensemble members differ in initial conditions, model physics, and (potentially, for future runs) SSTs. This unprecedented confluence of high spatial resolution and large ensemble size allows high signal-to-noise ratio and more robust estimates of uncertainty. This paper describes the experiment, compares model output with observations, shows select results for climate change simulations, and gives examples of the strength of the large ensemble size.
What a Record-Low Snowpack Means for Summer in the Northwest
Scott Pattee, a water supply specialist with the Natural Resources Conservation Service, has been monitoring snow levels in Washington for more than 20 years. The data he gathers helps scientist study climate trends, farmers plan their growing seasons, hydropower operators manage their reservoirs and municipalities provide water to citizens. This year is on track to be one of the lowest snow years on record. Across Washington state, average snowpack is 71 percent below normal levels. In some places, including the Olympic Peninsula, snowpack is 90 percent below normal levels. Things are looking even worse in Oregon. Statewide, average snowpack is 76 percent below normal levels. “One of our longest-monitored sites, near Bend, has the lowest snowpack ever recorded, breaking the 1977 record,” said Julie Koeberle, a hydrologist in Oregon with the Natural Resources Conservation Service. The Bend site has been monitored since the early 1950s.“All eyes will be pointing on southern and southeastern Oregon if things don’t improve,” Koeberle said. Some of the lowest snow levels can be found in those areas, where water scarcity has created drought conditions in recent years.
April Showers may Bring May Flowers, but Winter Snow is Water in the Bank
The type of precipitation falling from the sky matters, especially for delicate mountain ecosystems. It’s really all about snow – mountain ecosystems across the western United States are helped the most by precipitation in the form of snowfall. When snow falls on higher elevations it accumulates as snowpack and becomes a water “savings account” for lower elevation landscapes across the country for later in the year. While the east coast of the United States set records for snowfall this past winter, much of the western United States has entered into spring with substantially less mountain snowpack than previous years. In fact, the Cascade Mountains and the Sierra Nevada Mountains recorded the lowest snowpack ever measured in history, according to the U.S. Department of Agriculture. Through March 1 of this year, certain regions of Arizona, California, Idaho, Nevada, Oregon, and Washington have mountain snowpack at less than 25 percent of average from 1981-2010.
Regional Climate Change and National Responsibilities
Hansen, J., & Sato, M. 2016. Regional climate change and national responsibilities. Environmental Research Letters, 11(3), 034009. doi:10.1088/1748-9326/11/3/034009
James Hansen and Makiko Sato from the Earth Institute at Columbia University have released a report updating the effects of global warming in the Northern Hemisphere. Regional temperature data from 1951-1980 created a 50-year bell curve indicating average temperatures and anomalously cold and warm temperature for various regions of the world. Using these regional bell curves as baselines, Hansen and Sato compared them to bell curves of the same regions from 2005-2015 and calculated the difference in standard deviation. The average modern bell curve for the entire Northern Hemisphere is over one standard deviation warmer than the baseline bell curve. Hansen and Sato then examined bell curves of specific regions within the Northern Hemisphere, including the U.S., Europe, China, India, Middle East, Northern Africa, Central Africa, and SE Asia. The U.S. exhibited the smallest bell curve shift of approximately one standard deviation warmer in summer and 0.5 standard deviation warmer in winter, whereas the Middle East experienced the largest bell curve shift with a 2.4 standard deviation shift in summer and <1 standard deviation shift in winter. Tropical regions, such as central Africa and SE Asia exhibited bell curve shifts of approximately 2 standard deviations or more all year round. The authors concluded that warming the earth 2 C relative to pre-industrial temperatures will cause more extreme bell curve shifts than already observed. In addition, Hansen and Sato emphasized the responsibility of the developed world to recognize its role in reducing emissions and stressed the need to include societal costs in the price of fossil fuels.
Is the Monthly Temperature Climate of the United States Becoming More Extreme?
Kunkel, K. E., Vose, R. S., Stevens, L. E., Knight, R. W. (2015). Is the monthly temperature climate of the United States becoming more extreme? Geophysical Research Letters, 42, doi:10.1002/2014GL062035.
NOAA researchers used a new data set of monthly temperatures, adjusted for detected inhomogeneities, to evaluate whether monthly temperature climate of the U.S. has become more extreme. Over the past twenty to thirty years there has been a shift toward more frequent very warm months, and less frequent very cold months. Therefore, the overall monthly temperature climate has not become more extreme. Mid-twentieth century including the 1930s was an earlier period of frequent very warm months, a result of very warm daytime temperatures, while nighttime temperatures were not unusual. Compared to the earlier midcentury warm period, recent decades have been more (less) extreme in the summer (winter) in the west while Midwest summers have been less extreme.
Detection and Attribution of Climate Change Signal in Ocean Wind Waves
Mikhail Dobrynin, Jens Murawski, Johanna Baehr, and Tatiana Ilyina. 2015. Detection and Attribution of Climate Change Signal in Ocean Wind Waves. Journal of Climate, 28, 1578–1591. doi: http://dx.doi.org/10.1175/JCLI-D-13-00664.1
Researchers recently published a study in the Journal of Climate, which analyzed how surface waves in the ocean respond to variability and changes of climate. Observations and modeling studies indicate trends in wave height over the past decades. Nevertheless, it is currently impossible to discern whether these trends are the result of climate variability or change. The output of an Earth system model (EC-EARTH) produced within phase 5 of the Coupled Model Intercomparison Project (CMIP5) is used here to force a global Wave Model (WAM) in order to study the response of waves to different climate regimes. Detectable climate change signals were found in the current decade (2010–20) in the North Atlantic, equatorial Pacific, and Southern Ocean. Until the year 2060, climate change signals are detectable in 60% of the global ocean area. The authors show that climate change acts to generate detectable trends in wind speed and significant wave height that exceed the positive and the negative ranges of natural variability in different regions of the ocean. Moreover, in more than 3% of the ocean area, the climate change signal is reversible such that trends exceeded both positive and negative limits of natural variability at different points in time. These changes are attributed to local (due to local wind) and remote (due to swell) factors.
Projected changes in heat extremes and associated synoptic/mesoscale conditions over the northwest U.S.
Brewer, M.C. & Mass, C.F. 2016. Projected Changes in Heat Extremes and Associated Synoptic- and Mesoscale Conditions over the Northwest United States. Journal of Climate DOI: http://dx.doi.org/10.1175/JCLI-D-15-0641.1
Atmospheric scientists Matthew Brewer and Clifford Mass from the University of Washington examined the frequency, intensity and duration of heat waves in the northwest U.S., a region where synoptic and mesoscale circulations interact with local topography and land/water interfaces to generate complex and less understood heat extremes. Published in the Journal of Climate, the study used global and regional climate models to analyze changes to the conditions associated with heat extremes over the Northwest U.S. While the study’s findings projected increased temperatures and soil moisture declines, both associated with exacerbating heat extremes, findings also predicted less offshore flow due to narrower low-level zonal wind distribution. The dampening of strong offshore flows could mean less extreme warming events, as heat waves are associated with the strongest offshore flow. Results from this study indicate less severe increases in heat extremes for western Oregon and Washington compared to inland areas.
The changing shape of Northern Hemisphere summer temperature distributions
McKinnon, K. A., A. Rhines, M. P. Tingley, and P. Huybers. 2016. The changing shape of Northern Hemisphere summer temperature distributions, J. Geophys. Res. Atmos., 121, 8849–8868, doi:10.1002/2016JD025292.
A new study published in The Journal of Geophysical Research evaluated the distribution of summer temperature in the midlatitudes of the Northern Hemisphere. National Center for Atmospheric Research scientist, Karen McKinnon, and colleagues used data from over 4,000 weather stations to calculate the changes in daily maximum and minimum temperature distributions for peak summer between 1980 and 2015. The study found that North America and Eurasia displayed significant shifts in the estimated distributions of daily maximum and minimum temperatures. On a regional scale, variance in the distribution has increased in Eurasia and mostly decreased in North America.
2015 Sets New Global Temperature Record
NOAA Scientists confirmed 2015 to be the warmest year on record, according to this press release: "During 2015, the average temperature across global land and ocean surfaces was 1.62°F (0.90°C) above the 20th century average. This was the highest among all years in the 1880-2015 record, surpassing the previous record set last year by 0.29°F (0.16°C). This is also the largest margin by which the annual global temperature record has been broken. Ten months had record high temperatures for their respective months during the year. The five highest monthly departures from average for any month on record all occurred during 2015. Since 1997, which at the time was the warmest year on record, 16 of the subsequent 18 years have been warmer than that year."
Heavy Precipitation in a Changing Climate
Ban N., Schmidli, J., Schär, C. 2015. Heavy precipitation in a changing climate: Does short-term summer precipitation increase faster? Geophysical Research Letters. doi: http://dx.doi.org/10.1002/2014GL062588
Researchers from the Institute for Atmospheric and Climate Science at ETH Zurich have published a paper in Geophysical Research Letters discussing climate model projections of intensification of heavy precipitation events as a result of climate change. Researchers employed a convection-resolving model using a horizontal grid spacing of 2.2 km across an extended region covering the Alps and its larger-scale surrounding from northern Italy to northern Germany. Consistent with conventional climate models, high-resolution climate change simulations project pronounced decreases in mean summer precipitation over middle and southern Europe. The decrease is associated with frequency reductions of small and intermediate precipitation events. However, unlike previous studies, researchers found that both extreme day-long and hour-long precipitation events are projected to become more frequent and more intense, but not as pronounced as some previous studies suggested.
State of the Climate Report for 2014 Released
The American Meteorological Society has released its State of the Climate Report for 2014. Key findings from the report include: 1) greenhouse gas concentrations continued to rise, reaching historic high values; 2) 2014 was the warmest year on record; 3) the tropical Pacific Ocean is moving toward El Nino Southern Oscillation conditions; 4) sea surface temperatures reached a record high; 5) global average sea level rose to a record high; 6) sea ice extent in the Antarctic reached a record high (that is not a typo!); 7) the number of tropical cyclones was well above the historical yearly average.
Understanding ENSO Diversity
Capotondi A, Wittenberg AT, Newman M, Di Lorenzo E, Yu J-Y, Braconnot P, Cole J, Dewitte B, Giese B, Guilyardi E, Jin F-F, Karnauskas K, Kirtman B, Lee T, Schneider N, Xue Y, Yeh S-W (2015). Understanding ENSO Diversity. Bull. Amer. Meteor. Soc. 96, 921-938. doi: 10.1175/BAMS-D-13-00117.1.
A new article in the Bulletin of the American Meteorological Society (BAMS) discusses the diversity of behaviors that El Nino Southern Oscillation (called ENSO or just El Nino) years produce. Since this year has been widely discussed as being a large El Nino year, the article comes at a time when El Nino events are on the minds of many people in the western US. A typical way of understanding ENSO diversity is to compare sea surface temperature anomaly patterns at the peak of an El Nino year. Although there is debate over what will occur with ENSO patterns under climate change conditions, extreme El Nino events in terms of equatorial rainfall patterns are expected to increase in frequency (similar to what occurred in 1982-1983 and 1997-98 cases).
PNW Climate Outlook
This quarterly report from the Pacific Northwest Climate Impacts Research Consortium (CIRC) provides a seasonal wrap up of relevant regional issues along with an outlook for the coming season in Idaho, Oregon, Washington and Western Montana. To subscribe send an email to John Stevenson.
Impacts of Climate Change on Electric Power Supply in the Western United States
Matthew D. Bartos & Mikhail V. Chester (2015). Impacts of climate change on electric power supply in the western United States. Nature Climate Change: http://dx.doi.org/10.1038/nclimate2648.
Climate change may constrain future electricity generation capacity by increasing the incidence of extreme heat and drought events. Researchers estimate reductions to generating capacity in the Western United States based on long-term changes in streamflow, air temperature, water temperature, humidity and air density. Researchers simulate these key parameters over the next half-century by joining downscaled climate forcings with a hydrologic modelling system. For vulnerable power stations (46% of existing capacity), climate change may reduce average summertime generating capacity by 1.1–3.0%, with reductions of up to 7.2–8.8% under a ten-year drought. At present, power providers do not account for climate impacts in their development plans, meaning that they could be overestimating their ability to meet future electricity needs.
Elevation-dependent warming in mountain regions of the world
Mountain Research Initiative EDW Working Group. 2015. Elevation-dependent warming in mountain regions of the world. Nature Climate Change 5, 424–430. doi:10.1038/nclimate2563
The authors review important mechanisms that contribute to amplified warming at high elevations: snow albedo and surface-based feedbacks; water vapor changes and latent heat release; surface water vapor and radiative flux changes; surface heat loss and temperature change; and aerosols. All lead to enhanced warming with elevation, and it is believed that combinations of these mechanisms may account for contrasting regional patterns of elevation-dependent warming. The authors also discuss future needs to increase knowledge of mountain temperature trends and their controlling mechanisms through improved observations, satellite-based remote sensing and model simulations.
Critical feedbacks between Earth systems and human systems are missing from current climate models
Safa Motesharrei et al. 2016. Modeling Sustainability: Population, Inequality, Consumption, and Bidirectional Coupling of the Earth and Human Systems. National Science Review; nww081 DOI: 10.1093/nsr/nww081
Researchers from the University of Maryland recently published an article in the National Science Review urging climate scientists to increase their collaboration with social scientists and engineers in order to construct a more comprehensive model of the Earth-Human system. The authors wrote that key Human System variables such as demographics, inequality, economic growth, and migration are often not coupled with Earth System models, causing the current climate models used to miss important feedbacks in the Earth-Human system. Follow the links below to learn more about their proposed method for environmental modeling.
August and June-August global temperatures each reach record high, driven largely by record warm global oceans
According to NOAA scientists, the globally averaged temperature over land and ocean surfaces for August 2014 was the highest for August since record keeping began in 1880. It also marked the 38th consecutive August with a global temperature above the 20th century average. The last below-average global temperature for August occurred in 1976.
Hawaii Climate Information
Evapotranspiration of Hawai`i This website provides a set of maps of the spatial patterns of evapotranspiration for the major Hawaiian Islands. (http://evapotranspiration.geography.hawaii.edu)
Solar Radiation of Hawai`i This website provides a set of maps of the spatial patterns of solar radiation for the major Hawaiian Islands.( http://solar.geography.hawaii.edu)
Climate of Hawai`i: This website provides a set of maps of the spatial patterns of climate for the major Hawaiian Islands. (http://climate.geography.hawaii.edu)
Low growth in global carbon emissions continues for third successive year
Corinne Le Quéré et al. 2016. Global Carbon Budget. Earth System Science Data, 8 (2): 605 DOI: 10.5194/essd-8-605-2016
A collaborative team of scientists recently released a report in the journal Earth System Science Data of global carbon emissions for the year 2016. The report announced that this is the third year in row of almost no growth in carbon emissions, which contrasts the rapid growth of 2.3% per year up until 2013. Surprisingly coupled with this three-year no-growth trend is a period of strong economic growth. While the main reason for this slow down in fossil fuel emissions is due to China’s reduction of coal use, the U.S. also reduced its coal and exhibited a 2.6% decrease.
Ancient shellfish remains rewrite 10,000-year history of El Niño cycles
Carré et al., Holocene history of ENSO variance and asymmetry in the eastern tropical Pacific, Published Online August 7 2014, Science DOI: 10.1126/science.1252220
The planet’s largest and most powerful driver of climate changes from one year to the next, the El Niño Southern Oscillation in the tropical Pacific Ocean, was widely thought to have been weaker in ancient times because of a different configuration of the Earth’s orbit. But scientists analyzing 25-foot piles of ancient shells have found that the El Niños 10,000 years ago were as strong and frequent as the ones we experience today. The results, from the University of Washington and University of Montpellier, question how well computer models can reproduce historical El Niño cycles, or predict how they could change under future climates. UW news release link. The paper is now online and will appear in an upcoming issue of Science
State of Knowledge Report: Climate change in Puget Sound
State of Knowledge: Climate Change in Puget Sound is a comprehensive synthesis report summarizing relevant research on the likely effects of climate change on the lands, water, and people of the Puget Sound wardregion. Part of the Climate Impacts Group’s “State of Knowledge” series, this report details observed and projected changes for Puget Sound’s climate, water resources, forests, species and ecosystems, coasts and ocean, infrastructure, agriculture, and human health in an easy-to-read summary format designed to complement the foundational literature (peer-reviewed science, community and agency reports, and publicly available datasets) from which it draws. The report also describes local climate change risk reduction activities and highlights data resources available to support local climate adaptation efforts. The work was funded by the U.S. Environmental Protection Agency via the Puget Sound Institute at UW Tacoma, the National Oceanic and Atmospheric Administration, and the State of Washington.
NOAA releases database of climate science providers for the Western U.S.
The National Oceanic and Atmospheric Administration (NOAA) recently released its “Climate Services Provider Database,” providing a comprehensive directory of climate service providers in the Western United States. The database can be searched for the type of information or service, such as workshops, decision support tools, vulnerability assessments, or training and education. The site can also be searched by geographic area or sector to find providers that serve that area. This database was created through a partnership between NOAA Western Region Collaboration Team, the NOAA-RISA Western Water Assessment, and the NOAA-RISA Climate Assessment for the Southwest. The database is in pilot form. It is intended to catalog climate service providers in NOAA's Western Region (AZ, CA, CO, ID, MT, NV, NM, OR, UT, WA, and WY).
Analysis of Western Water and Drought Legislation
Pervaze A. Sheikh, Betsy A. Cody, Charles V. Stern, Nicole T. Carter, Linda Luther, Claudia Copeland. 2015. Western Water and Drought: Legislative Analysis of H.R. 2898 and S. 1894. Congressional Research Service. www.crs.gov.
The Congressional Research Service has released an analysis report of the latest legislation introduced to Congress addressing nationwide and western-specific drought, as well as gaps in water supply and demand. The report discusses many of the bills being considered including how they differ and what topics are being omitted from the overall conversation. Of these bills, two have gained the most congressional and public attention: the Western Water and American Food Security Act (H.R. 2898) and the California Emergency Drought Relief Act of 2015 (S.1894). Both bills are primarily focused on water projects and management during drought, but contain different approaches. Neither bill addresses the broad suite of drought impacts and policies like effects on wildfire and agricultural assistance programs. Questions of how to reconcile environmental protections with increased water demand, how to allocate authority between federal and local involvement, and a list of other issues have been raised by these proposed bills, and are all discussed in this report.
Worst MegaDrought in 1,000 years
Hannah Hoag, Oct 16, 2014, Nature News, doi:10.1038/nature.2014.16157 synthesizes four journal articles]: http://www.nature.com/news/us-dust-bowl-unrivalled-in-past-1-000-years-1.16157
Using the North American Drought Atlas, a 2,005-year record derived from tree-ring chronologies that reconstructs drought and precipitation patterns, researchers have found that the 1934 drought that covered more than 70% of western North America and was 30% more intense than the second most severe drought in the region, which happened in 1580…. The cause is attributed to a high-pressure ridge that blocked wet weather from California and the Northwest…. A similar, but more persistent, atmospheric pattern was at work off the California coast this past winter, moving storms north, and research is tracing this recent event to human-made warming of the western Pacific Ocean.
EPA’s Adaptation Resource Center
The U.S. Environmental Protection Agency recently updated its Adaptation Resource Center (ARC-X). ARC-X is an interactive resource to help local governments effectively deliver climate information services to their communities. Decision makers can create an integrated package of information tailored specifically to their needs. Users can use the online center to explore the risks posed by climate change to their issues of concern; relevant adaptation strategies; case studies illustrating how other communities have successfully adapted to those risks; tools to replicate their successes; and EPA funding opportunities.
Extreme events of 2013 explained from a climate perspective
he National Air and Space Administration has released an ultra-high-resolution computer model to give scientists a stunning new look at how atmospheric carbon dioxide travels around the globe. Plumes of carbon dioxide in the simulation swirl and shift as winds disperse the greenhouse gas away from its sources. The simulation also illustrates differences in carbon dioxide levels in the northern and southern hemispheres and distinct swings in global carbon dioxide concentrations as the growth cycle of plants and trees changes with the seasons. The simulation is the product of a new computer model that is among the highest-resolution ever created.
Near-term Acceleration in the Rate of Temperature Change
Smith, S.J., Edmonds, J., Hartin, C.A., Mundra, A., Calvin, K. 2015. Near-term acceleration in the rate of temperature change. Nature Climate Change, doi: http://dx.doi.org/10.1038/nclimate2552.
Anthropogenically driven climate changes, which are expected to impact human and natural systems, are often expressed in terms of global-mean temperature. The rate of climate change over multi-decadal scales is also important, with faster rates of change resulting in less time for human and natural systems to adapt. We find that present trends in greenhouse-gas and aerosol emissions are now moving the Earth system into a regime in terms of multi-decadal rates of change that are unprecedented for at least the past 1,000 years. The rate of global-mean temperature increase in the CMIP5 archive over 40-year periods increases to 0.25 ± 0.05 °C per decade by 2020, an average greater than peak rates of change during the previous one to two millennia. Regional rates of change in Europe, North America and the Arctic are higher than the global average. Research on the impacts of such near-term rates of change is urgently needed.
Atmospheric river landfall-latitude changes in future climate simulations
Shields, C. A. & Kiehl, J.T. 2016. Atmospheric river landfall-latitude changes in future climate simulations, Geophys. Res. Lett. 43, doi:10.1002/2016GL070470.
Scientists from the National Center for Atmospheric Research recently published a study examining projected changes to latitude of landfall for atmospheric rivers. The study examined climate simulations of atmospheric rivers in the North Pacific and the North Atlantic using version 4 of the Community Climate System Model. The study found that the atmospheric rivers along the west coast of the U.S. are projected to move toward the equator and experience increased rainfall intensity. Concerning the simulations of atmospheric rivers along the North Atlantic, the study found projected landfall to be more dependent upon eddy-driven jets and seasons.
Temperature records occur in clusters
Abatzoglou, J.T., and R. Barbero. 2014. Observed and projected changes in absolute temperature records across the contiguous United States, Geophysical Research Letters, 41, 6501–6508. doi: http://dx.doi.org/10.1002/2014GL061441
Researchers analyzed the chronology of absolute highest and lowest temperature records for minimum and maximum temperatures across the US using climate station data from 1920 to 2013. Many of the absolute highest temperature records were set during the 1930s, during the most severe drought of the twentieth century. Additionally, during the same time period over 25% of the weather stations recorded their highest minimum daily temperature. The authors then used 20 global climate models to analyze the evolution of absolute temperature records through 2049 under a high-end greenhouse gas scenario. These models predicted that high temperatures are expected to increase and low temperatures are also expected to increase. The projected novel temperature records may necessitate adaptation measures to minimize damage to ecosystems.
NASA Study Finds Carbon Emissions Could Dramatically Increase Risk of U.S. Megadroughts
Cook, B.I., Ault, T.R., Smerdon, J.E. 2015. Unprecedented 21st century drought risk in the American Southwest and Central Plains. Science Advances, doi: http://dx.doi.org/10.1126/sciadv.1400082
A new NASA study found that continued increases in human-produced greenhouse gas emissions drives up the risk of severe droughts in the southwest and Great Plains regions. Results, based on projections from 17 climate models, suggest that droughts will last for 30, 40, 50 years. If greenhouse gas emissions continue to increase along current trajectories throughout the 21st century, there is an 80% likelihood of a decades-long megadrought in the Southwest and Central Plains between the years 2050 and 2099.
Developing an indicator-focused climate change assessment in Idaho
Klos PZ et al. (2015) Indicators of Climate Change in Idaho: An Assessment Framework for Coupling Biophysical Change and Social Perception. Weather, Climate and Society 7: 238-254. doi: 10.1175/WCAS-D-13-00070.1
A new study describes an indicator-focused climate change assessment of Idaho that provides an interdisciplinary framework for understanding indicators of local to regional-level climate change and a proof-of-concept case example that incorporates both social and biophysical data and indicators. A number of surveys were completed to understand the most important data needs for end-users. Survey participants identified precipitation indicators as being the most important climate measure, and streamflow timing, volumetric stream discharge and baseflow stream discharge as being the most important water resources metrics. Forest metrics included wildland fire severity and vegetation distribution. Rangeland survey participants identified vegetation indicators. Agricultural participants were concerned with drought and the duration of the growing season. Overall, changes to water resources and wildfire risk were identified as being of primary concern. Using results from the survey, the authors developed a datasets for 15 biophysical indicators and quantitative changes in the indicators were determined using time series analysis from 1975 to 2010. The framework used in the study could be used for other climate change assessments at local to regional scales that combine both quantitative and qualitative metrics.
What the Integrated Scenarios Project Says About the Northwest Under Climate-Change
The project is Integrated Scenarios of the Future Northwest Environment, a collaborative venture that brought together scientists from several separate Northwest climate research organizations. Integrated Scenarios’ goal was deceptively simple: explain what the latest climate science says about the Northwest’s future climate, vegetation, and hydrology. Getting the answer would take some doing. To get the best science to managers, a project was needed that was systematic, interdisciplinary, and, well, integrated. That’s because an accurate picture of a climate-changed Northwest would have to include not only computer-modeling the region’s climate but its vegetation and hydrology as well.
Attribution of climate extreme events
Trenberth, K.E., Fasullo, J.T., Shepard, T.G. 2015. Attribution of climate extreme events. Nature Climate Change. doi:10.1038/nclimate2657
Authors of a new paper published in Nature Climate Change suggest a different framing for the attribution of extreme weather events- one which asks why such extremes unfold the way they do. Specifically, they suggest that it is more useful to regard extreme weather events as being largely unaffected by climate change, and to question whether known changes in the climate system's thermodynamic state affected the impact of the particular event. Some examples briefly illustrated include 'snowmaggedon' in February 2010, superstorm Sandy in October 2012 and supertyphoon Haiyan in November 2013, and, in more detail, the Boulder floods of September 2013, all of which were influenced by high sea surface temperatures that had a discernible human component.
Report on Climate Change Vulnerability and Adaptation and Mitigation Strategies
Creighton J, Strobel M, Hardegree S, Steele R, Van Horne B, Gravenmier B, Owen W, Peterson D, Hoang L, Little N, Bochicchio J, Hall W, Cole M, Hestvik S, Olson J (2015). Northwest Regional Climate Hub Assessment of Climate Change Vulnerability and Adaptation and Mitigation Strategies. A. Perry, Ed., United States Department of Agriculture, 52 pp.
A new report produced by a partnership between the Corvallis Forestry Sciences Laboratory, the Northwest Climate Hub and the USDA Forest Service looks at climate change vulnerabilities and adaptation strategies. The assessment discusses where scientists and practitioners need to focus in the Northwest to deal with climate risks. The report cites irrigation water loss, increases in wildfire frequency, and increases in diseases and insect pest populations. Melting Arctic ice could lead to greater numbers of invasive species, as well as more opportunities for regional trade and shipping. The report identifies risks specific to areas west of the Cascades, east of the Cascades and in Alaska and explains expected climate change impacts across the Northwest.
NOAA 2013 Global Climate Report
The average global temperature for 2013 tied as the fourth warmest year since record keeping began in 1880, according to NOAA scientists. It also marked the 37th consecutive year with a global temperature above the 20th century average. The last below-average annual temperature was 1976. Including 2013, all 13 years of the 21st century (2001-2013) rank among the 15 warmest in the 134-year period of record. The three warmest years on record are 1998, 2005, and 2010. This analysis is from NOAA's National Climatic Data Center in Asheville, North Carolina.
Catastrophic fires may ebb with added moisture
According to the National Interagency Fire Center’s latest Wildland Fire Outlook report, wet weather from El Niño may cause drop in the number of wildfires experienced in the U.S. compared to the record-breaking fire season in 2015. The mountainous West has had large amounts of snowpack, potentially delaying the start of the fire season, particularly in higher-elevation forested areas. Overall, this is a positive outcome of El Niño, however the Outlook projected the Pacific Northwest to have “normal significant wildland fire potential” due to the warmer-than-average weather experienced in the month of April that led to a drop in snowpack.
Extreme Weather Events are Expected to Double
Wenju Cai, Guojian Wang, Agus Santoso, Michael J. McPhaden, Lixin Wu, Fei-Fei Jin, Axel Timmermann, Mat Collins, Gabriel Vecchi, Matthieu Lengaigne, Matthew H. England, Dietmar Dommenget, Ken Takahashi, Eric Guilyardi. 2015. Increased frequency of extreme La Niña events under greenhouse warming. Nature Climate Change. http://dx.doi.org/10.1038/nclimate2492
The El Niño/Southern Oscillation is the planet’s strongest source of interannual climate variability, alternating irregularly between El Niño and La Niña. The 1998–1999 extreme La Niña event that followed the 1997–1998 extreme El Niño event switched extreme El Niño-induced severe droughts to devastating floods in western Pacific countries, and vice versa in the southwestern United States. During La Niña events temperatures drop in the central Pacific Ocean. Research led by Wenju Cai suggests that La Niña events will become twice as frequent, occurring once every 13 years instead of once every 23 years. 75% of this increase will occur in years following extreme El Niño events, leading to more frequent swings between opposite climatic extremes.
Climate change will drive stronger, smaller storms in U.S., new modeling approach forecasts
Won Chang, Michael L. Stein, Jiali Wang, V. Rao Kotamarthi, Elisabeth J. Moyer. Changes in Spatiotemporal Precipitation Patterns in Changing Climate Conditions. Journal of Climate, 2016; 29 (23): 8355 DOI: 10.1175/JCLI-D-15-0844.1
A new approach for modeling storm behavior has been developed by researchers from the University of Chicago and Argonne National Laboratory. The new framework, published in the Journal of Climate, uses new statistical methods to identify the properties of individual storms which allows researchers to track changes in storm frequency, size and duration. Due to the finer resolution of this new approach, the researchers detected changes in storm features that explained former contradictory results. Stronger storms that have been predicted with future climate change, for example, are not projected to be accompanied by an increase in overall rainfall. Using the new approach, the authors were able to explain this puzzling phenomenon: individual storms exhibited a decrease in land area covered during the summer.
Hotter Days, Heavier Rains Projected for United States
Vose, R.S., & Coauthors. (2014) Improved Historical Temperature and Precipitation Time Series for U.S. Climate Divisions. J. Appl. Meteor. Climatol., 53, 1232–1251. doi.org/10.1175/JAMC-D-13-0248.1
(From The Climate CIRCulator, a publication of The Pacific Northwest Climate Impacts Research Consortium (CIRC) and The Oregon Climate Change Research Institute (OCCRI).) Many types of extreme events will increase in size and frequency in the future. That is the conclusion of climate experts who recently compared climate models to observed data. The scientists evaluated global climate models’ simulations of extreme events in the United States. They also examined the models’ future projections of the frequency and magnitude of extremes, from hot days to heavy rainfall. The questions were posed during a workshop at the Coupled Model Intercomparison Project phase 5 (CMIP5). The workshop’s findings — published in the Bulletin of the American Meteorological Society — echo earlier studies. Conclusions include:
Hotter Temperatures: More high-temperature extremes and fewer low-temperature extremes are on the horizon. In other words, the highs are getting higher and the lows are also higher. By 2100, under the high-emission scenario, the 20-year annual maximum temperature (so-called because it would occur once in 20 years, on average) likely will increase between 5 and 7 degrees Celsius in the Pacific Northwest. The 20-year annual minimum temperature could rise by 10 degrees inland and 5 to 7 degrees on the coast.
Historical simulations of extreme temperatures are largely consistent with recorded observations. The exception occurred in the mid-1980s to mid-1990s, the researchers note. Record highs occurred slightly less often and record lows occurred slightly more often in the simulations than in the observations. (Compared to observations, simulated warm extremes were less than 2 degrees Celsius warmer, while cold extremes were a little more than 2 degrees colder in the western United States.)
Heavier Precipitation: Heavy precipitation events are on the rise across the United States, and that trend is projected to continue. But the climate models vary substantially, both in how much heavy precipitation already has increased and in how much it will increase going forward.
Depending on the emissions scenario, models project a 50 percent to 90 percent increase in the annual fraction of precipitation falling in the wettest rainstorms across the country by 2100. In the Northwest, the 20-year annual maximum precipitation is projected to happen three to four times more frequently by 2100. All models project an increase in the extreme precipitation index, a regionally averaged measure of extreme precipitation that has increased more in the real world than models simulate during the last four decades. In general, there are large differences between climate models in simulating historical heavy rainfall, but that large spread across models is smaller for future projections.
Great Basin Weather and Climate Dashboard
This website provides up to date climate and weather data and forecasts/outlooks for the Great Basin including temperature, precipitation, drought, snowpack and hydrologic information. (Some of the information includes the entire western U.S.) The Dashboard is a joint effort amongst the Western Regional Climate Center, California and Nevada Applications Program, the USDA Farm Service Agency and the Great Basin LCC.
Climate change to shift global pattern of mild weather
Karin van der Wiel, Sarah B. Kapnick, Gabriel A. Vecchi. 2017. Shifting patterns of mild weather in response to projected radiative forcing. Climatic Change, DOI: 10.1007/s10584-016-1885-9
A new study from Princeton University examined the impact of climate change on the global frequency of mild weather. Led by climate scientist Karin van der Wiel, the study found that the global annual number of mild days will decrease by 10-13% by the end of the century, which is equivalent to approximately 10 days. On the regional scale, the study concluded a more varied projection of mild day frequency change. Tropical regions in Africa, Asia and Latin America were projected to exhibit the largest decline in mild days, from 15-50 less days per year. Conversely, regions in the mid-latitudes such as parts of the United States, Canada, and northern Europe were projected to gain mild weather days.
Climate change related changes in extreme rainfall will vary among regions
S. Pfahl, P. A. O’Gorman, E. M. Fischer. 2017. Understanding the regional pattern of projected future changes in extreme precipitation. Nature Climate Change (7) 423–427. DOI: 10.1038/nclimate3287
A recent study by researchers from MIT and the Swiss Federal Institute of Technology in Zurich showed that extreme rain events in most regions of the world are likely to increase in intensity by 3 to 15 percent, for every degree Celsius that the planet warms. If global average temperatures rise by 4 degrees Celsius over the next hundred years, as many climate models predict given relatively high CO2 emissions, much of North America and Europe would experience increases in the intensity of extreme rainfall of roughly 25 percent. The study, published in Nature Climate Change, finds that variation in the change in extreme precipitation from region to region can be explained by different changes in the strength of local wind patterns. As a region warms due to human-induced emissions of carbon dioxide, winds loft that warm, moisture-laden air up through the atmosphere, where it condenses and rains back down to the surface. But changes in strength of the local winds also influence the intensity of a region's most extreme rainstorms. The authors argue that being able to predict the severity of the strongest rain events, on a region-by-region basis, could help local planners prepare for potentially more devastating storms.
The rise in atmospheric water vapor—a significant greenhouse gas—over the past 30 years can be tied to human activities
Chung et al., published online before print July 28, 2014, PNAS, doi: 10.1073/pnas.1409659111
The fact that water vapor is the most dominant greenhouse gas underscores the need for an accurate understanding of the changes in its distribution over space and time. Although satellite observations have revealed a moistening trend in the upper troposphere, it has been unclear whether the observed moistening is a facet of natural variability or a direct result of human activities. Here, researchers used a set of coordinated model experiments to confirm that the satellite-observed increase in upper-tropospheric water vapor over the last three decades is primarily attributable to human activities. This attribution has significant implications for climate sciences because it corroborates the presence of the largest positive feedback in the climate system.
Evaluation of a regional climate modeling effort for the western United States
Li, S., Mote, P. W., Rupp, D. E., Vickers, D., Mera, R., & Allen, M. (2015). Evaluation of a Regional Climate Modeling Effort for the Western United States Using a Superensemble from Weather@ home*. Journal of Climate, 28(19), 7470-7488.
Simulations from a regional climate model (RCM) as part of a superensemble experiment were compared with observations of surface meteorological variables over the western United States. The RCM is the Hadley Centre Regional Climate Model, version 3, with improved physics parameterizations (HadRM3P) run at 25-km resolution and nested within the Hadley Centre Atmosphere Model, version 3 (HadAM3P). Overall, the means of seasonal temperature were well represented in the simulations; 95% of grid points were within 2.78, 2.48, and 3.68C of observations in winter, spring, and summer, respectively. The model was too warm over most of the domain in summer except central California and southern Nevada. HadRM3P produced more extreme temperatures than observed. The overall magnitude and spatial pattern of precipitation were well characterized, though HadRM3P exaggerated the orographic enhancement along the coastal mountains, Cascade Range, and Sierra Nevada. HadRM3P produced warm/dry northwest, cool/wet southwest U.S. patterns associated with El Niño. However, there were notable differences, including the locations of the transition from warm (dry) to cool (wet) in the anomaly fields when compared with observations, though there was disagreement among observations. HadRM3P simulated the observed spatial pattern of mean annual temperature more faithfully than any of the RCM–GCM pairings in the North American Regional Climate Change Assessment Program (NARCCAP). Errors in mean annual precipitation from HadRM3P fell within the range of errors of the NARCCAP models. Last, this paper provided examples of the size of an ensemble required to detect changes at the local level and demonstrated the effect of parameter perturbation on regional precipitation.
Earth’s climate may not warm as quickly as expected, suggest new cloud studies
Wogan, T. (2016). Earth’s climate may not warm as quickly as expected, suggest new cloud studies. Science. doi:10.1126/science.aag0567
“Clouds need to condense around small particles called aerosols to form, and human aerosol pollution—primarily in the form of sulfuric acid—has made for cloudier skies. Scientists have generally assumed Earth’s ancient skies were much sunnier than they are now. But today, three new studies show how naturally emitted gases from trees can also form the seed particles for clouds. The results not only point to a cloudier past, but they also indicate a potentially cooler future: If Earth’s climate is less sensitive to rising carbon dioxide (CO2) levels, as the study suggests, future temperatures may not rise as quickly as predicted.”
Artificial Amplification of Warming Trends Across Western Mountains
Oyler, J. W., S. Z. Dobrowski, A. P. Ballantyne, A. E. Klene, and S. W. Running (2015). Artificial amplification of warming trends across the mountains of the western United States, Geophysical Research Letters, 42, 153–161, doi: http://dx.doi.org/10.1002/2014GL062803.
Observations from the main mountain climate station network in the western U.S. suggest that higher elevations are warming faster than lower elevations. This has led to the assumption that elevation-dependent warming is prevalent throughout the region with impacts to water resources and ecosystem services. Researchers from the University of Montana critically evaluated this network's temperature observations and show that extreme warming observed at higher elevations is the result of systematic artifacts and not climatic conditions. With artifacts removed, the network's 1991–2012 minimum temperature trend decreases from +1.16°C decade−1 to +0.106°C decade−1 and is statistically indistinguishable from lower elevation trends. In the context of a warming climate, this artificial amplification of mountain climate trends has likely compromised our ability to accurately attribute climate change impacts across the mountainous western U.S.
Clear Evidence Found Between Climate Change and Heat Waves
A new report produced by the National Academies of Sciences, Engineering and Medicine, examined the latest understanding of “event attribution,” or scientists’ ability to attribute extreme climatic events to climate change. It is more difficult to characterize an individual weather event than a global trend, however the science surrounding such characterization has rapidly evolved in recent years. This report concluded that it is now possible for scientists to quantitatively state the extent to which climate change has influenced the magnitude and frequency of some classes of extreme events. The most apparent classes of events that scientists can associate with climate change are the ones directly related to temperature. Therefore, scientists have the highest understanding of the influence of climate change on heat waves and extreme cold events, followed by drought and extreme precipitation, but the lowest understanding of event classes such as wildfires, cyclones, or severe convective storms.
Western Snow Surveyors Have Fun, but Their Data are Deadly Serious
The Natural Resources Conservation Service (NRCS) funds snow-surveying operations in 12 Western states, including Alaska. Measuring the depth and weight of the snow and doing some basic calculations to determine water content solves the problem of how much water to expect in the spring once the snow begins to melt and make its way down the mountains. "In certain regions and at certain sites, we are seeing changes associated with the changing climate," Strobel, the director of NRCS's National Water and Climate Center, stated. Some sites are registering more rain rather than snow, and within streams themselves, "we're seeing the peak in the streamflow occurring earlier, indicating the snowmelt is happening at an earlier period."
The West Coast is in Hot Water
The warm water in the eastern Pacific over the past two years is a harbinger of things to come for the region. Ocean temperatures have been rising around the world and are expected to keep warming, and the eastern Pacific could see the odd conditions of the past two years become commonplace by mid-century. Just how far-reaching the impacts will be and which species will adapt and which will fail to is something scientists are still trying to untangle. The causes for the current eastern Pacific warm temperatures — what Washington state climatologist Nick Bond has coined "the blob" — are not fully known, but are most likely natural. The blob has spread across an expanse of water 1,000 miles across with above-normal water temperatures running from the surface to as deep as 300 feet. While human-induced warming is heating seas around the world, Bond said that’s not the main cause for this particular hot spot. “It’s mostly a fluke of climate variability,” Bond said. “At least part of it can be linked to deep convection in the far western tropical Pacific.”
There’s one place in the world that's getting colder instead of warmer
Summarized by Deaton, J. (2016, June 30). There's one place in the world that's getting colder instead of warmer. http://www.businessinsider.com/one-place-in-the-world-that-isnt-warming-...
Armour, K. C., Marshall, J., Scott, J. R., Donohoe, A., & Newsom, E. R. (2016). Southern Ocean warming delayed by circumpolar upwelling and equatorward transport. Nature Geoscience 9(7), 549-554. doi:10.1038/ngeo2731
According to an article published in Nature Geoscience, while Arctic sea ice has diminished, Antarctic sea ice has persisted and even grown. New research shows that as surface waters migrate northward, they are replaced by cooler waters from the depths of the ocean--waters that have not seen the light of day in hundreds or thousands of years. These ancient currents have been protected from rising temperatures. Cold Antarctic waters originate in the North Atlantic, the northernmost stop along an oceanic conveyor belt that extends the length of the planet. Arctic waters travel south along the bottom of the sea towards Antarctica. Once they hit Earth’s southern pole, they rise to the top and return north along the surface of the ocean, absorbing heat along the way. This system dampens warming in the Antarctic and exacerbates warming in the Arctic. While some may see this as good news for sea- level rise, the research shows that it makes little difference, as cool waters are responsible for preserving sea ice. What the research does show is that rising temperatures are far from uniform.
Successful simulation of the Pineapple Express
Shields, A. & Kiehl, J.T. 2016. Simulating the Pineapple Express in the half degree Community Climate System Model, CCSM4, Geophys. Res. Lett. 43, 7767–7773, doi:10.1002/2016GL069476.
A recent publication in Geophysical Research Letters synthesizes the ability of the Community Climate System Model (CCSM4) to capture the Pineapple Express, an atmospheric river that originates in the deep tropics and extends poleward along the west coast of North America. Recent analysis of the CCSM4 high-resolution ensemble simulations shows accurate capture of the spatial and temporal climatology of the Pineapple Express. Further analysis of these simulations indicates a significant increase in storm duration and intensity of precipitation associated with landfall of the atmospheric river.
A new statistically downscaled climate model dataset covering the conterminous U.S.
A new statistically downscaled climate model dataset of the conterminous U.S., funded by the NW CSC and the SE CSC, is now available for download. Statistical downscaling is a method of acquiring small-scale future climate predictions using climate data produced at a large scale. The downscaling process generates information that is useful for making decisions and adapting to the impacts of climate change on a local or regional scale. This dataset is called MACAv2-METDATA and it contains daily downscaled meteorological and hydrological projections for the conterminous U.S. at 4-km resolution. The dataset includes variables such as maximum and minimum temperature, precipitation, humidity data, downward solar radiation, and eastward and northward wind. This dataset can be downloaded from the USGS GeoData Portal (GDP). The GDP houses large datasets, often the products of large-scale modeling efforts such as climate downscaling, and makes these datasets easier for scientists, managers, and the public to access and process the information for additional analyses.
Briefing on SNOTEL Sensor Upgrade and its Implications
Upgrades of a system of temperature sensors called SNOTEL (Snow Telemetry) caused inhomogeneities (step shifts) in recorded temperatures. This was particularly problematic for SNOTEL stations in the Intermountain West of the United States (Colorado, Utah, and Wyoming) because climate studies in recent decades have suggested that regions of higher elevation are warming faster, and many of these studies used SNOTEL data in their research. This report from the Western Water Assessment analyzed the inhomogeneities of SNOTEL data in order to promote a broader awareness of the issue. The study showed clearly where and when the recorded temperatures shifted, and the degree of inaccuracy of this un-corrected data. The authors conclude by stressing that SNOTEL data was not used by climate scientists for the analyses of temperature trends found in regional, national, and international assessment reports, such as the IPCC and the National Climate Assessment.
NASA Releases Detailed Global Climate Change Projections
On June 9th NASA released data showing how temperature and rainfall patterns worldwide may change through the year 2100 because of growing concentrations of greenhouse gases in Earth’s atmosphere. The new dataset shows projected changes worldwide on a regional level in response to different scenarios of increasing carbon dioxide. The high-resolution data, which can be viewed on a daily timescale at the scale of individual cities and towns, will help scientists and planners conduct climate risk assessments to better understand local and global effects of hazards, such as severe drought, floods, heat waves and losses in agriculture productivity. The new dataset is the latest product from the NASA Earth Exchange (NEX), a big-data research platform within the NASA Advanced Supercomputing Center at the agency's Ames Research Center in Moffett Field, California. In 2013, NEX released similar climate projection data for the continental United States that is currently being used to quantify climate risks to the nation’s agriculture, forests, rivers and cities.
Soils could release much more carbon than expected as climate warms
Caitlin E. Hicks Pries, C. Castanha, R. Porras, M. S. Torn. The whole-soil carbon flux in response to warming. Science, 2017; eaal1319 DOI: 10.1126/science.aal1319
Scientists from the Department of Energy’s Lawrence Berkeley National Laboratory conducted an unprecedented field experiment, examining the impact of warming on the organic carbon content in soils. They found that CO2 production from all soil depths increased significantly with 4℃ warming. While most in-situ experiments only monitor warming of the surface soil, this study showed that all depths responded to warming with similar temperature sensitivities. Lead author Caitlin Hicks Pries stated, "if our findings are applied to soils around the globe that are similar to what we studied, meaning soils that are not frozen or saturated, our calculations suggest that by 2100 the warming of deeper soil layers could cause a release of carbon to the atmosphere at a rate that is significantly higher than today, perhaps even as high as 30 percent of today's human-caused annual carbon emissions depending on the assumptions on which the estimate is based.”
Weather becoming more conducive to wildfires
Jolly, W.M., Cochrane, M.A., Freeborn, P.H., Holden, Z.A., Brown, T.J., Williamson, G.J., Bowman, D.M.J.S. 2015. Climate-induced variations in global wildfire danger from 1979 to 2013. Nature Communications 6, 7537. doi:10.1038/ncomms8537
A new study argues that fire risks across the planet are rising as a result of climate change. Wildfire risk may be partially due to a decreasing ability of land and vegetation to extract carbon from the atmosphere and thus partially offset greenhouse gas emissions. As a result, wildfires are acting as a positive feedback – in other words, fires are getting worse because of climate change, while also making climate change worse. Matt Jolly, lead author of the study and a researcher with the U.S. Forest Service’s Fire Sciences Laboratory in Missoula, Montana, found that the duration of weather most conducive to fires has increased by 18.7% between 1979 to 2013. Jolly also found that the area burned increased as well.
Natural Defenses from Hurricanes and Floods
Glick P, Kostyack J, Pittman J, Briceno T, Wahlund N (2015). Natural Defenses from Hurricanes and Floods: Protecting America’s Communities and Ecosystems in an Era of Extreme Weather. National Wildlife Federation.
A new report from the National Wildlife Federation discusses how to protect communities and ecosystems as extreme weather conditions increase. The report focuses on coastal regions of the Atlantic and Pacific Oceans and regions surrounding streams and rivers. It suggests that millions of people are in danger that live and work close to these areas and are at risk from floods and hurricanes. Policies need to be put into place to make these regions safer by restoring natural infrastructure such as wetlands, dunes, riparian zones, shorelines and natural open space. The report emphasizes the five following principles to accomplish these goals in policymaking: 1) better evaluation and articulation of risk may lead to more risk reduction; 2) proactively investing in certain risk reduction measures may produce large savings over the long term; 3) investments in natural infrastructure will maximize resilience to floods and hurricanes; 4) actuarially-sound insurance provides a way to incentivize risk reduction; 5) consideration of social equity is an important component of natural catastrophe policy.
Great Basin Weather and Climate Dashboard
This website provides up to date climate and weather data and forecasts/outlooks for the Great Basin including temperature, precipitation, drought, snowpack and hydrologic information. (Some of the information includes the entire western U.S.) The Dashboard is a joint effort amongst the Western Regional Climate Center, California and Nevada Applications Program, the USDA Farm Service Agency and the Great Basin LCC.
2014 Hottest Year on Record
Preliminary analysis from a global network of measurements by NASA and NOAA suggest that 2014 is the warmest year since record-keeping began in 1880 – and possibly the warmest in two millennia. 2014 was 0.04 degrees Celsius warmer than the previous record-holder 2010, and 0.69 degrees Celsius warmer than the twentieth-century average. These results reinforce that the planet is warming and that average global temperatures are currently exceeding those seen historically.
NOAA’s Climate Prediction Center releases US Winter Outlook
Forecasters at NOAA’s Climate Prediction Center issued the U.S. Winter Outlook today favoring cooler and wetter weather in Southern Tier states with above-average temperatures most likely in the West and across the Northern Tier. This year’s El Niño, among the strongest on record, is expected to influence weather and climate patterns this winter by impacting the position of the Pacific jet stream.
Office of the Washington State Climatologist issues a monthly newsletter
The Office of the Washington State Climatologist issues a monthly newsletter that summarizes the WA climate for the previous month, includes a precipitation and temperature outlook, and also includes a brief summary of an interesting aspect of the weather or climate of WA, among a few other sections: See www.climate.washington.edu/newsletter for copies and to join the listserv.
Carbon-hungry plants impede growth rate of atmospheric carbon dioxide
Trevor F Keenan, I. Colin Prentice, Josep G Canadell, Christopher A Williams, Han Wang, Michael Raupach, G. James Collatz. Recent pause in the growth rate of atmospheric CO2 due to enhanced terrestrial carbon uptake. Nature Communications, 2016; 7: 13428 DOI: 10.1038/ncomms13428
A team of scientists led by the Berkeley Lab have identified the variable causing a slower atmospheric CO2 growth rate than the amount emitted by fossil fuel: plants. The scientists believe that rising CO2 levels in the atmosphere caused an increase in the rate of photosynthesis of land-based plants while the rate of respiration remained the same, consequently making plants even more of a carbon sink than they formerly were.
Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming
McGregor et al., Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming, Nature Clim. Change, 2014/08/03 advance online publication, http://dx.doi.org/10.1038/nclimate2330
An unprecedented strengthening of Pacific trade winds since the late 1990s has caused widespread climate perturbations, including rapid sea-level rise in the western tropical Pacific, strengthening of Indo-Pacific ocean currents, and an increased uptake of heat in the equatorial Pacific thermocline. The corresponding intensification of the atmospheric Walker circulation is also associated with sea surface cooling in the eastern Pacific, which has been identified as one of the contributors to the current pause in global surface warming. In spite of recent progress in determining the climatic impacts of the Pacific trade wind acceleration, the cause of this pronounced trend in atmospheric circulation remains unknown. Here researchers analyse a series of climate model experiments along with observational data to show that the recent warming trend in Atlantic sea surface temperature and the corresponding trans-basin displacements of the main atmospheric pressure centres were key drivers of the observed Walker circulation intensification, eastern Pacific cooling, North American rainfall trends and western Pacific sea-level rise. The study suggests that global surface warming has been partly offset by the Pacific climate response to enhanced Atlantic warming since the early 1990s.
Climate Change Preparedness Plan for the North Olympic Peninsula
A new report produces a climate change preparedness plan for the North Olympic Peninsula. The project synthesized the best available climate change projections with local stakeholder expertise of vulnerable sectors to ultimately develop climate change preparedness strategies for the North Olympic Peninsula. With this project and other similar efforts, the North Olympic Peninsula has a unique opportunity to promote collaboration on climate change adaptation between federal, state, local, and tribal governments, non-profit organizations, academic institutions, and private businesses. The project brought together more than 175 partners over the course of one year. Through virtual meetings and a series of in-person workshops, a climate change stakeholder network was built and the best available climate change science was compiled. Potential areas of concern were identified and assessed, and adaptation strategies were evaluated for Jefferson and Clallam counties. The project’s efforts resulted in an extensive report that has the potential to build overall climate resilience in the North Olympic Peninsula and promote the best possible future outcomes for the region’s inhabitants and ecosystems.
March and 1st Quarter of 2015 were Warmest in 136 Years
According to NOAA scientists, the globally averaged temperature over land and ocean surfaces for March 2015 was the highest for the month since record keeping began in 1880. The year-to-date (January-March) globally averaged temperature was also record high. This monthly summary from NOAA's National Centers for Environmental Information is part of the suite of climate services NOAA provides to government, the business sector, academia and the public to support informed decision-making.
Projected Changes in Snowfall Extremes and Interannual Variability of Snowfall in the Western US
Lute, A. C., J. T. Abatzoglou, and K. C. Hegewisch (2015), Projected changes in snowfall extremes and interannual variability of snowfall in the western United States, Water Resour. Res., 51, 960–972, doi:10.1002/2014WR016267.
Projected warming will have significant impacts on snowfall accumulation and melt, with implications for water availability and management in snow-dominated regions. Changes in snowfall extremes are confounded by projected increases in precipitation extremes. Downscaled climate projections from 20 global climate models were bias-corrected to montane Snowpack Telemetry stations across the western US to assess mid-21st century changes in the mean and variability of annual snowfall water equivalent (SFE) and extreme snowfall events. Declines in annual SFE and number of snowfall days were projected for all stations. At climatologically cooler locations, such as in the Rocky Mountains, changes in the magnitude of snowfall events mirrored changes in the distribution of precipitation events, with increases in extremes and less change in warmer locations. Common to both warmer and colder sites was a relative increase in the magnitude of snowfall extremes compared to annual SFE and a larger fraction of annual SFE from snowfall extremes.
Signatures of extreme precipitation events in the western U.S.
McCabe-Glynn, S., K. R. Johnson, C. Strong, Y. Zou, J. Y. Yu, S. Sellars, and J. M. Welker 2016. Isotopic signature of extreme precipitation events in the western U.S. and associated phases of Arctic and tropical climate models, J. Geophys. Res. Atmos., 121, 8913–8924, doi:10.1002/2016JD025524.
A collaborative team of climate scientists recently published a study examining the projected changes to the intensity and frequency of atmospheric rivers, or extreme precipitation events, in western North America. The team utilized climate and precipitation isotope data to evaluate atmospheric rivers in California from 2001 to 2011. The study found that 90% of atmospheric river events reaching California occurred during the negative Arctic Oscillation, which could indicate an association with periods of warm temperatures in the higher latitudes. In addition to this dataset, the team examined precipitation data across the entire western U.S. and found that the wettest conditions occurred when the negative Arctic Oscillation, the negative Pacific/North America pattern, and the positive Southern Oscillation were in sync. This also coincided with an increase in precipitation in the southwestern U.S. and a decrease in the Northwest. The team additionally concluded that the landfall location, intensity and isotopic composition of atmospheric river events depends upon the type of El Nino event (Central Pacific or Eastern Pacific).
Why two-degrees Celsius?
The Intergovernmental Panel on Climate Change (IPCC) states that we must keep the average global temperature increase since the pre-industrial era below 2 °C. Why do we focus so heavily on this specific target? This target number (2 °C) was derived from the work of William Nordhaus who stated that beyond this point “the effects of global warming on society became dangerous and problematic.” This specific two-degree target became well established in the policy domain when it was toted as a potentially achievable target during talks that preceded the Kyoto Protocol. Thereafter, two degrees Celsius became known as a “tipping point”, after which ecosystems would be increasingly disrupted. Given present projection trends we are expected to reach and surpass this two-degree tipping point within just 30 years.
Projected Changes of Snowfall in the Western United States
Lute, A. C., Abatzoglou, J. T., Hegewisch, K. C. 2015. Projected changes in snowfall extremes and interannual variability of snowfall in the western United States. Water Resources Research, doi: http://dx.doi.org/ 10.1002/2014WR016267
Projected warming will have signiﬁcant impacts on snowfall accumulation and melt, with implications for water availability and management in snow-dominated regions. Researchers from University of Idaho recently published a paper in Water Resources Research which used downscaled climate projections from 20 global climate models to assess mid-21st century changes in the mean and variability of annual snowfall water equivalent (SFE) and extreme snowfall events across the western United States. Declines in annual SFE and number of snowfall days were projected for all snowpack telemetry stations analyzed. The projected declines in annual SFE and snowfall days, along with projected increases in winter precipitation suggests that in high elevation locations, snow events are likely to shift to rain events, increasing the probability of rain-on-snow events and the magnitude of rainfall extremes with implications for flood risk in some watersheds.
NASA: California “Rain Debt” Equal to Average Full Year of Precipitation
Savtchenko, A.K., Huffman, A., Vollmer B. 2015. Assessment of Precipitation Anomalies in California Using TRMM and MERRA data. Journal of Geophysical Research: Atmospheres. 10.1002/2015JD023573
A new NASA study concluded that California has accumulated a debt of around 20 inches of precipitation from 2012 through 2015. This is approximately the amount of precipitation that typically falls in the state in a given year. Between 20-50 percent of California’s precipitation comes from atmospheric rivers, which move over the Pacific Ocean and are responsible for precipitation falling in others of the West Coast as well. The study authors attribute the majority of the precipitation debt to a high-pressure system in the atmosphere over the eastern Pacific Ocean that has prevented the formation of atmospheric rivers since 2011.
Office of the Washington State Climatologist issues a monthly newsletter
The Office of the Washington State Climatologist issues a monthly newsletter that summarizes the WA climate for the previous month, includes a precipitation and temperature outlook, and also includes a brief summary of an interesting aspect of the weather or climate of WA, among a few other sections.
Anthropogenic Contribution to Global Occurrence of Heavy-Precipitation and High-Temperature Extremes
Fischer, E. M., and R. Knutti. 2015. Anthropogenic contribution to global occurrence of heavy-precipitation and high-temperature extremes. Nature Climate Change 5: 560-564. http://dx.doi.org/ 10.1038/nclimate2617
Climate change includes not only changes in mean climate but also in weather extremes. For a few prominent heatwaves and heavy precipitation events a human contribution to their occurrence has been demonstrated. Here we apply a similar framework but estimate what fraction of all globally occurring heavy precipitation and hot extremes is attributable to warming. We show that at the present-day warming of 0.85 °C about 18% of the moderate daily precipitation extremes over land are attributable to the observed temperature increase since pre-industrial times, which in turn primarily results from human influence. For 2 °C of warming the fraction of precipitation extremes attributable to human influence rises to about 40%. Likewise, today about 75% of the moderate daily hot extremes over land are attributable to warming. It is the most rare and extreme events for which the largest fraction is anthropogenic, and that contribution increases nonlinearly with further warming. The approach introduced here is robust owing to its global perspective, less sensitive to model biases than alternative methods and informative for mitigation policy, and thereby complementary to single-event attribution. Combined with information on vulnerability and exposure, it serves as a scientific basis for assessment of global risk from extreme weather, the discussion of mitigation targets, and liability considerations.
Despite Drought in California and the Northwest, May 2015 was the Wettest Month Ever for the Lower 48 States
According to a report just released by the National Centers for Environmental Information (formerly the National Climatic Data Center), May of 2015 was it the wettest May on record for the contiguous 48 states. It was also the wettest month ever in 121-years of record-keeping.
‘Blob’ in Pacific Ocean ramps up ozone levels above Western U.S.
Jaffe, D. A., and L. Zhang. 2017. Meteorological anomalies lead to elevated O3 in the western U.S. in June 2015, Geophys. Res. Lett., 44, doi:10.1002/2016GL072010.
The anomalous mass of warm sea surface water that persisted across the northeastern Pacific Ocean in winter through early summer of 2014-2015 (known as the “Blob”) has corresponded with an enhanced ozone layer across a large portion of the western U.S. Values of this enhancement were taken from the Mount Bachelor Observatory. These findings were published in Geophysical Research Letters and authored by researchers from the University of Washington. The authors concluded that the high ozone concentration was associated with increased temperatures, reduced cloud fraction, increased stagnation, and increased biogenic emissions.
2016 is set to break even the temperature records of 2015
According to an assessment by the World Meteorological Organization, 2016’s global temperatures are approximately 1.2°C above pre-industrial averages, and are potentially going to break the record-breaking year of 2015. The report gives provisional information on the status of global temperature, oceans, greenhouse gas concentrations, ice and snow cover, extreme weather, and humanitarian crises.
Attribution of global glacier mass loss to anthropogenic and natural causes
Ben Marzeion, J. Graham Cogley, Kristin Richter, and David Parkes, Science 1254702Published online 14 August 2014 [DOI:10.1126/science.1254702
The ongoing global glacier retreat is affecting human societies by causing sea-level rise, changing seasonal water availability, and increasing geohazards. Melting glaciers are an icon of anthropogenic climate change. However, glacier response times are typically decades or longer, which implies that the present-day glacier retreat is a mixed response to past and current natural climate variability and current anthropogenic forcing. Here, we show that only 25 ± 35% of the global glacier mass loss during the period from 1851 to 2010 is attributable to anthropogenic causes. Nevertheless, the anthropogenic signal is detectable with high confidence in glacier mass balance observations during 1991 to 2010, and the anthropogenic fraction of global glacier mass loss during that period has increased to 69 ± 24%.
NOAA 2013 Global Climate Report
The average global temperature for 2013 tied as the fourth warmest year since record keeping began in 1880, according to NOAA scientists. It also marked the 37th consecutive year with a global temperature above the 20th century average. The last below-average annual temperature was 1976. Including 2013, all 13 years of the 21st century (2001-2013) rank among the 15 warmest in the 134-year period of record. The three warmest years on record are 1998, 2005, and 2010. This analysis is from NOAA's National Climatic Data Center in Asheville, North Carolina. To access the summary and full report, visit: http://www.ncdc.noaa.gov/news/ncdc-releases-2013-global-climate-report.
Measuring the human impact of weather
The World Meteorological Organization (WMO) recently announced world records for the highest reported historic death tolls from tropical cyclones, tornadoes, lightning and hailstorms. This announcement marks the first time the official WMO Archive of Weather and Climate Extremes has broadened its scope from strictly temperature and weather records to address the impacts of specific events. The in-depth investigation into documented mortality records for these five specific weather-related events was conducted by an international WMO committee of 19 experts. The highest mortality associated with a weather event was the estimated 300,000 people that were killed as result of the passage of a tropical cyclone through Bangladesh (at time of incident, East Pakistan) on Nov. 12-13, 1970.
Climate Change Vulnerability and Adaptation in the Blue Mountains Region
Halofsky, J.E.; Peterson, D.L., eds. 2016. Climate change vulnerability and adaptation in the Blue Mountains. Gen. Tech. Rep. PNW-GTR-xxx. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. Xxx p.
A new report from the Blue Mountains Adaptation Partnership (BMAP) identifies climate change issues relevant to resource management in the Blue Mountains Region and offers solutions to help transition the region into a warmer climate. The BMAP is a science-management partnership composed of Malheur National Forest, Umatilla National Forest, Wallowa-Whitman National Forest, the U.S. Forest Service Pacific Northwest Research Station and Pacific Northwest Region, the University of Washington, and the Climate Impacts Research Consortium at Oregon State University. This report summarizes effects of climate change on the streamflow and snowpack of the Blue Mountains Region, and projects the impact these changes will have on the region’s ecosystem.
Longest record of continuous carbon flux data is now publicly available
An international database, called FLUXNET, has been collecting and managing measurements of how carbon dioxide, water vapor, and heat circulate through soil, plants and the atmosphere from 450 sites worldwide. The database contains sites that have been measuring flux for nearly 25 years, making them some of the longest records of continuous carbon flux measurements to date. Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory have undergone quality checks of the database and have developed user friendly software to accompany the tool. The database, now available to the public, allows scientists to ask unprecedented questions about long-term effects, such as how changes in the concentration of carbon dioxide over time affects photosynthesis or water within an ecosystem.
Improved Winter Projections for the Northwest U.S.
Isla R. Simpson, Seager, R., Ting, M., & Shaw, T. A. (2015). “Causes of change in Northern Hemisphere winter meridional winds and regional hydroclimate.” Nature Climate Change, 6, 65-71, doi:10.1038/nclimate2783
Changes to hydrology, particularly precipitation, have long been a challenge to climate modelers. As a result, there is a wide range of projections for how rainfall will change in the Northwest United States. Isla Simpson and other scientists from the Lamont-Doherty Earth Observatory at Columbia University, evaluated existing models in order to see whether the wide range could be narrowed. The scientists systematically eliminated atmospheric responses to climate change that did not directly affect precipitation in the Northwest. By doing this, they were able to identify consistencies across all models, and pegged one atmospheric response as the key stimulus for precipitation changes- a strengthened jet stream. The authors then focused on how well each model simulated the jet stream and discovered that models with weaker simulations generally exhibited more extreme increases in Northwestern precipitation. This finding carries important implications, as many winter projections could be overestimations.
Climate Science: The Future of Coastal Ocean Upwelling
Many climate models predict that coastal upwelling will intensify in three of the most productive marine ecosystems of the world. This result comes at a time when scientists are still debating the evidence supporting an increase in coastal upwelling and its effects on coastal ecosystems and global carbon cycling. Increased upwelling currents will strongly affect marine ecosystems at Eastern Boundary Upwelling Systems, but the long-term future of coastal acidification, dead zones, and primary productivity probably depends on the properties of the water that comes to the surface.
Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise
Oceans are now warmer than ever before in recorded history
Mean summer sea surface temperatures in 2014 were the highest ever recorded according to Axel Timmermann, a climate scientist with the International Pacific Research Center, University of Hawaii at Manoa. Overall global ocean warming was driven largely by warming in the North Pacific.
New NOAA report projects possible 8 feet of sea level rise by 2100
The Sea Level Rise and Coastal Flood Hazard Scenarios and Tools Interagency Task Force recently released a report updating global sea level rise projections. The authors report that new scientific literature points to an extreme upper-bound scenario of 2.5m of global mean sea level rise by 2100. This is an increase in 0.5m from the upper-bound scenario enlisted in the Third National Climate Assessment (NCA3), and is due to the incorporation of Greenland and Antarctica rapid ice melt. In addition to the updated global mean sea level rise projection, the report discussed regional factors that affect sea level rise along the United States coastline. They found that the Pacific Northwest is projected to exhibit lower sea level rise than the global mean. The technical report will contribute to the Task Force’s long-term effort to incorporate updated sea level rise and coastal flood hazard data into regionally appropriate scenarios to be utilized by individual agencies and local management.
El Niño: Beyond the Hype
According to an article in Bay Nature Magazine, the arrival of this year’s El Niño was different from past El Niño years, in part because the Pacific Ocean was already extraordinarily warm from the “Blob” before the warm tropical El Niño water had even arrived. This article discusses what this unusual combination of phenomena will mean for the coast of the Western United States. Ecological changes associated with the arrival of abnormally warm water have been recorded at nearly every trophic level. From large changes in plankton composition with the arrival of tropical plankton species to northern waters, to the appearance of thousands of pelagic red crab that haven’t been seen in Northern California since the strong El Niño in 1983. NOAA ecologist John Field is calling these bizarre observations “El Niño harbingers”. Field’s NOAA survey has also documented changes in fish abundance, such as higher numbers of young rockfish and market squid and lower numbers of sardines and anchovies. The impact that these changes on lower trophic levels will have on higher trophic levels has been observed to be more complicated than anticipated. For example, seabirds such as Cassin’s auklets and common murres had two failed nesting seasons in a row around Santa Cruz but a successful nesting season at the Farallones. Point Blue Conservation Science marine ecologist Jaime Jahncke notes that even in a warm year there are some refuge areas that stay relatively cold, where the food web can continue normally. He relates this to the “Blob” and El Niño-driven hot water leaving pockets of cool water in a few places off the coast of Northern California.
The web site for the Salish Sea Marine Survival Project is now live
The site provides details about a new, comprehensive, international research effort to determine the primary factors affecting the survival of juvenile salmon and steelhead in the Salish Sea. The launch was made possible with help from Pacific Salmon Commission’s Southern Fund Committee, Washington State, and 40+ other federal, state, tribal, and academic project partners and public and private funders.
Ocean’s most oxygen-deprived zones to shrink under climate change
Deutsch et al., Centennial changes in North Pacific anoxia linked to tropical trade winds, Science 8 August 2014: Vol. 345 no. 6197 pp. 665-668, DOI: 10.1126/science.1252332
As the complex story of climate change unfolds, many of the endings are grim. But there are exceptions. Predictions that the lowest-oxygen environments in the ocean would get worse may not come to pass. Instead, University of Washington research shows climate change, as it weakens the trade winds, could shrink the size of these extreme low-oxygen waters. “The tropics should actually get better oxygenated as the climate warms up,” said Curtis Deutsch, a UW associate professor of oceanography. He is lead author of the study published Aug. 8 in Science.
West Coast Ocean Acidification and Hypoxia Science Panel
The West Coast Ocean Acidification and Hypoxia Science Panel has a new website. Learn more about the scientists on the Panel, explore their vision, and discover how they are advancing a bold new knowledge base in service of the region's future. The panel was established in 2013 by the California Ocean Protection Council. The website will provide a venue to disseminate and distribute products that are produced by the Panel as they work to summarize information on key themes identified by decision makers.
Farmed fish living in high CO2 conditions shed light on likely long-term impacts of CO2 on marine life
Robert P. Ellis, Mauricio A. Urbina, Rod W. Wilson. Lessons from two high CO2 worlds - future oceans and intensive aquaculture. Global Change Biology, 2016; DOI: 10.1111/gcb.13515
Authors of a recent paper in Global Change Biology show that farmed fish often live in CO2 conditions 10 times higher than their wild cousins, and argue that these systems could serve as "a giant long-term laboratory experiment" to study the long-term impact of CO2 on marine life. At the same time, these studies may help farmers optimize their practices to improve an important means of food production for our growing global population.
Ocean acidification could weaken sea urchin sperm
Campbell, A. L., Levitan, D. R., Hosken, D. J., & Lewis, C. 2016. Ocean acidification changes the male fitness landscape. Scientific Reports, 6, 31250; doi: 10.1038/srep31250
A recent study published in Nature Scientific Reports examined the impact of ocean acidification (OA) on sea urchin sperm competitiveness. The researchers conducted a series of paired competitive fertilization trials under current ocean conditions and future OA conditions in the sea urchin Paracentrotus lividus. The study found that males with faster sperm had greater competitive fertilization success in both seawater conditions, but more motile sperm lost competitive fertilization under OA conditions. The results of this study suggest that the best males in current conditions are not necessarily best under OA, which could possibly change future traits of male fitness and subsequently alter the genetic landscape of marine species.
Arctic Warming will Promote Atlantic-Pacific Fish Interchange
Wisz, M.S., Broennimann, O., Gronkjaer, P., Moller, P.R., Olsen, S.M., Swingedouw, D., Hedeholm, R.B., Nielsen, E.E., Guisan, A. & Pellissier, L. 2015. Arctic warming will promote Atlantic-Pacific fish interchange. Nature Climate Change, doi: http://dx.doi.org/ 10.1038/nclimate2500
For millions of years, extremely cold arctic water temperatures and low nutrient levels have served as a barrier separating marine organisms in the North Atlantic from those in the North Pacific. However, a recent study published in Nature Climate Change, finds that rising ocean temperatures are dissolving the barrier. Researchers projected the potential northward progression of 515 species following climate change and report the rate of potential species interchange between the Atlantic and the Pacific via the Northwest Passage and the Northeast Passage. By 2100 up to 41 species could enter the Pacific and 44 species could enter the Atlantic, via one or both passages. This exchange of fish species may trigger changes for biodiversity and food webs in the North Atlantic and North Pacific, with ecological and economic consequences to ecosystems that at present contribute 39% to global marine fish landings
Vulnerability and Adaptation of U.S. Shellfisheries to Ocean Acidification
Ekstrom, J.A., Suatoni, L., Cooley, S.R., Pendleton, L.H., Waldbusser, G.G., Cinner, J.E., Ritter, J., Langdon, C., van Hooidonk, R., Gledhill, D., Wellman, K., Beck, M.W., Brander, L.M., Rittschof, D., Doherty, C., Edwards, P.E.T., Portela, R. 2015. Vulnerability and adaptation of US shellfisheries to ocean acidification. Nature Climate Change. doi: http://dx.doi.org/ 10.1038/nclimate2508
A recently published article in Nature Climate Change presents a multidisciplinary vulnerability analysis of coastal human communities in the Unites States. Researchers focused analysis on shelled mollusc harvests, likely to be harmed by ocean acidification. Results suggest that marine ecosystems in the Pacific Northwest and Southern Alaska will be the first affected. Additionally, this study highlights regions in the U.S. most vulnerable to ocean acidification, information gaps, and opportunities to adapt through local actions.
Largest Ever Toxic Algae Bloom Contaminate Coasts from California to Alaska
Scientists are investigating what could be the largest toxic algae bloom ever recorded off the West Coast. The effects stretch from Central California to British Columbia, and possibly as far north as Alaska. Dangerous levels of the natural toxin domoic acid have shut down recreational and commercial shellfish harvests in Washington, Oregon and California. At the same time, two other types of toxins rarely seen in combination are turning up in shellfish in Puget Sound and along the Washington coast. Scientists suspect this year’s unseasonably high temperatures are playing a role, along with “ the blob” — a vast pool of unusually warm water that blossomed in the northeastern Pacific late last year. The blob has morphed since then, but offshore waters are still about two degrees warmer than normal. Domoic-acid outbreaks aren’t unusual in the fall, but the toxin has never hit so hard in the spring, or required such widespread closures for crabs.
Flood protection plans by wealthy nations may work poorly in the long run
Deltas are highly sensitive to increasing risks arising from local human activities, land subsidence, regional water management, global sea-level rise, and climate extremes. Tessler et al. quantified changing flood risk due to extreme events using an integrated set of global environmental, geophysical, and social indicators. Although risks are distributed across all levels of economic development, wealthy countries effectively limit their present-day threat by gross domestic product-enabled infrastructure and coastal defense investments. In an energy-constrained future, such protections will probably prove to be unsustainable, raising relative risks by four to eight times in the Mississippi and Rhine deltas and by one-and-half to four times in the Chao Phraya and Yangtze deltas. The current emphasis on short-term solutions for the world’s deltas will greatly constrain options for designing sustainable solutions in the long term.
Numerous Genetic Differences Found Between Wild and Farm Salmon
Mark R. Christie, Melanie L. Marine, Samuel E. Fox, Rod A. French, Michael S. Blouin. 2016. A single generation of domestication heritably alters the expression of hundreds of genes. Nature Communications. 7: 10676 DOI: 10.1038/ncomms10676
The genetic processes by which domestication of plants and animals occurs is largely unknown. In order to better understand these underlying mechanisms, a new study from Oregon State University compared the genome of wild salmon and first-generation farm salmon living in the same habitat. Scientist, Mark Christie and his colleagues collected wild-born and first generation hatchery steelhead trout from the Hood River, Oregon and performed a series of crosses. The scientists then measured differential gene expression between wild offspring (wild x wild) and first-generation hatchery offspring (hatchery x hatchery). The results showed 723 genes that were differentially expressed between the two groups. The genetic pathways of these differentially expressed genes were mainly for wound repair, immunity, and metabolism, all traits that would help fish adapt to a more crowded hatchery environment. The study also examined reciprocal crosses (hatchery x wild, wild x hatchery) to rule out the possibility that maternal effects or natural sampling noise were not the cause of the difference in gene expression. The study suggests that the earliest stages of domestication stimulate massive, heritable change to gene expression.
Global Sea Level Rise Scenarios for the United States National Climate Assessment
Global sea level rise (SLR) has been persistent over the past several decades, and the trend expected to continue though the next century. SLR poses a serious threat to the United States as more than eight million people live in regions at risk of coastal flooding, and many of the nation’s military, energy, and commerce resources lie on or in close proximity to the ocean. This report, created by NOAA’s Climate Program Office, along with contributing authors from various federal and academic science institutions, is a synthesis of SLR scientific literature and a set of plausible future SLR scenarios. The report presents four future SLR scenarios ranging from 0.2 meters to 2.0 meters by 2100. The group of scenarios serves as a set of reasonable trajectories that can be used as a starting point for assessment experts and their stakeholders to evaluate vulnerability, impacts, and adaptation strategies in the face of uncertain futures.
New Technique Quickly Predicts Salt Marsh Vulnerability
A USGS-led team of researchers has developed a convenient tool for land managers to assess the vulnerability of coastal salt marshes. The method compares the ratio of ponds, channels, and tidal flats to marsh vegetation to act as a surrogate for more intensive assessment methods. The technique was tested in eight already-studied marshes, and the team discovered every marsh they assessed to be losing ground. Refuge manager, Bill Peterson, stated that the new tool “will help us figure out where we can make a difference with restoration techniques. It will also help us determine which areas are beyond restoration. This ensures that we’re using our limited resources effectively to strengthen and enhance these valuable natural areas.”
Ocean acidification will make it hard for mussels to hang on
Johnson, L. (2016, July 06). Ocean acidification will make it hard for mussels to hang on experiments suggest; British Columbia, CBC News. Retrieved July 26, 2016, from http://www.cbc.ca/news/canada/british-columbia/ocean-acidification-will-...
According to a presentation by Emily Carrington, a professor at the University of Washington in Seattle, at the annual meeting of the Society of Experimental Biology, warmer ocean temperatures and rising ocean acidification levels pose a threat to mussels by weakening the threads they produce to bind themselves to their substrate. If those threads break — or fail to attach at all — the mussel will be tossed from the tidal zone it thrives in to deeper, calmer waters, with less food and more predators. Warmer water means the native mussel, Mytilus trossulus, produces fewer, weaker threads. More acidic water means the biological 'glue' — which needs higher pH--doesn't stick as well. Even though oceans are not yet so acidic that the mussels are unable to develop their “lifelines”, things are heading in that direction.
Climate change increasing beach salinity
Geng, X., Boufadel, M.C., & Jackson, N.L. 2016. Evidence of salt accumulation in beach intertidal zone due to evaporation. Nature Scientific Reports 6(31486). doi:10.1038/srep31486
A team of researchers from the New Jersey Institute of Technology collected 400 samples of water stored in soil and rock (pore water) at a beach in Delaware Bay and analyzed them for salinity levels. The team found that, while seawater has a salt concentration of 25 grams per liter, the salinity levels from the pore water were averaging 60 grams per liter. According to Xiaolong Geng, the lead author of the study, "these elevated levels can only be caused by evaporation, as there is no other mechanism for increasing the salt in pore water.” The authors also stressed that this could be exacerbated as temperatures warm, possibly negatively impacting local ecosystems such as mussels and crabs that are sensitive to changes in salinity.
Rising water temperatures endanger health of coastal ecosystems
Schaefer, S.C. & J.T. Hollibaugh. 2017. Temperature Decouples Ammonium and Nitrite Oxidation in Coastal Waters. Environmental Science & Technology, 51 (6): 3157 DOI: 10.1021/acs.est.6b03483
Increasing water temperatures are causing the accumulation of nitrite in marine environments throughout the world, according to new research from the University of Georgia. Too much nitrite can alter the kinds and amounts of single-celled plants living in marine environments, potentially affecting the animals that feed on them. It can also lead to toxic algal blooms and create dead zones where no fish or animals can live. Lead author, James Hollibaugh, and researcher, Sylvia Schaefer, found peak concentrations of nitrite alongside massive increases in numbers of the microorganisms that produce it in the coastal waters off Sapelo Island, Georgia, in data collected over the course of eight years. Although most researchers believe nitrite accumulation is a consequence of oxygen deficiency in a marine environment, Hollibaugh and Schaefer thought something else had to be driving the accumulation. After performing lab experiments that exposed single-celled organisms to varying water temperatures, the researchers discovered that higher temperatures prompted the microorganisms to produce more nitrite. To test whether a similar pattern could be seen in the field, Schaefer and Hollibaugh analyzed data from 270 locations across the U.S., France and Bermuda, ultimately affirming the relationship between higher temperatures and nitrite accumulation. Their study was recently published in Environmental Science and Technology.
Anticipated Effects of Climate Change on Coastal Upwelling Ecosystems
Bakun, A., Black, B. A., Bograd, S. J., Garc’ia-Reyes, M., Miller, A. J., Rykaczewski, R. R., & Sydeman, W. J. (2015). Anticipated Effects of Climate Change on Coastal Upwelling Ecosystems. Current Climate Change Reports, 1(2), 85–93. http://doi.org/10.1007/s40641-015-0008-4
A new study published as part of the collection, Ecological Impacts of Climate Change, discussed the projected physical changes and biological responses of four coastal upwelling zones due to increased greenhouse gases in the atmosphere. Bakun et al. (2015) used existing research to review four upwelling zones that occur on the eastern boundary of the Atlantic and Pacific Ocean basins. The review was built as a framework of predicted ecological changes that could be used to understand future measured changes to these systems. The authors found that increased warming in the atmosphere will generally intensify coastal upwelling. This is most likely because the air temperature above land will rise faster than that above water during warm seasons, causing an intensified temperature gradient along coastlines and therefore stronger upwelling-favorable winds. These physical changes can have many biological impacts, mainly due to spatial and temporal ecological changes. With stronger winds, more plankton grazers may be pushed offshore, causing increased phytoplankton blooms. This could lead to increased frequency of hypoxic events, as well as decreased light penetration to deeper coastal waters. Changes in biological distribution could also impact species at higher trophic levels. The authors note the resilience of upwelling systems to variability, however conclude that these potential future changes will display unprecedented variability.
Kelp beats the heat
Daniel Reed, Libe Washburn, Andrew Rassweiler, Robert Miller, Tom Bell, Shannon Harrer. Extreme warming challenges sentinel status of kelp forests as indicators of climate change. Nature Communications, 2016; 7: 13757 DOI: 10.1038/ncomms13757
Scientists from the University of California, Santa Barbara recently released their study examining the effect of extreme warming on kelp forests. The researchers collected a decade of oceanographic and ecological data along an 80km stretch of the Santa Barbara Channel and were able to capture the recent extreme warming event along the western coast of North America. Using this temporal record, the team assessed the kelp forest’s resilience throughout the warming event and, surprisingly, found this ecosystem to exhibit little sensitivity. This study is significant because it contradicts the sentinel status given to kelp forests, as they are commonly understood to be sensitive to temperature change.
Newly discovered phytoplankton groups appear to favor warmer oceans
Chang Jae Choi, Charles Bachy, Gualtiero Spiro Jaeger, Camille Poirier, Lisa Sudek, V.V.S.S. Sarma, Amala Mahadevan, Stephen J. Giovannoni and Alexandra Z. Worden. Newly discovered deep-branching marine plastid lineages are numerically rare but globally distributed. Current Biology, 2017 DOI: 10.1016/j.cub.2016.11.032
An international team of scientists published new research on the discovery of new phytoplankton groups. Published in Current Biology, the team found high abundance of the new group of phytoplankton species in warmer, low-nutrient surface waters. These desert-like waters included the Sargasso Sea, Bay of Bengal and the North Pacific Gyre and represent projected future conditions under climate change. The team discovered these new groups through continuous year-round sampling and the construction of the Baseline Initiative, a database of over 6,000 RNA gene sequences. The study emphasized the need to better understand these groups of phytoplanktons species in order to gain a clearer picture of marine ecosystems under increased warming.
New method for monitoring global ocean warming – without harming whales
Zhao, Z. 2016. Internal tide oceanic tomography. Geophys. Res. Lett., 43, 9157–9164, doi:10.1002/2016GL070567.
Zhongxiang Zhao, a researcher with the Applied Physics Laboratory at the University of Washington, recently published a new method for monitoring global ocean warming called Internal Tide Oceanic Tomography (ITOT). Tangential to a method proposed by oceanographer Walter Munk in the 1970s, Zhao founded the ITOT method on the concept that warmer water exhibits faster wave propagation. This new method measures the travel time of internal waves across the ocean and relates this speed to the temperature of the water. Internal wave travel time can be measured using satellite tomography, making the ITOT method an inexpensive, environmentally friendly method for obtaining temperature measurements of the global ocean at unprecedented depths.
Warming Oceans Storing Up Long Term Climate Impacts, says WMO
Rising ocean temperatures are likely to have “major implications” for the development of climate change, the World Meteorological Organization said. The majority of warming linked to soaring levels of greenhouse gas emissions was being stored in the upper and lower levels of the seas, it said in its annual Status of the Global Climate report for 2014. Sea-surface temperatures were “much warmer than average” across the north Pacific, southwest Pacific, Indian Ocean as well as the polar region of the North Atlantic. Last year was the hottest on record, with global average temperatures 0.57 °C above the 1961-1990 average of 14 °C.
Climate change means days are getting longer
Mitrovica, J.X., Hay, C.C., Morrow, E., Kopp, R.E., Dumberry, M. and Stanley, S., 2015. Reconciling past changes in Earth’s rotation with 20th century global sea-level rise: Resolving Munk’s enigma. Science Advances,1(11), p.e1500679.
Harvard University researchers have published a new study in Science Advances that provides an answer to a long-held scientific puzzle of how shrinking glaciers are affecting the earth’s rotation and axis. A 2002 paper written by oceanographer Walter Munk attempted to solve this puzzle, but concluded that, even with average sea level rises of 2mm a year, there would be no change to Earth’s rotation or axis. Now coined “Munk’s enigma”, Jerry Mitrovica and fellow Harvard scientists revisited this 2002 research. Using the latest climate science knowledge, they applied updated models and assumptions to Munk’s study and found that the glacier melting of the 20th century had indeed caused the Earth to slow and wobble. The study found that the period of a day is now a millisecond longer than it was a century ago. Changes to Earth’s axis and rotation is set to become more pronounced with the global average sea level rise now over 3mm, according to the IPCC.
EPA Climate Ready Estuaries Program Launches Redesigned Website
Resources are now easier to find and webpages are now searchable. New features include interactive maps of Climate Ready Estuary projects, king tides, and more. Update your bookmarks to the new address: http://www2.epa.gov/cre
Assessing Coastal Manager Science Needs
Thorne, K.M., Powelson, K.W., Bui T.D., Freeman, J.Y. Takekawa, C.M., Janousek, C.N., Buffington, K.J., and D.L. Elliott-Fisk 2016. Assessing coastal manager science needs and disseminating science results for planning. Data Summary Report Prepared for the California and North Pacific Landscape Conservation Cooperatives. USGS Western Ecological Research Center, Vallejo, CA. 110 pp.
In this new report, The USGS Coastal Ecosystems Response to Climate Change program collected and analyzed extensive field data of elevation, inundation, tidal range, accretion, and plant communities to assess the vulnerability of tidal wetland habitats to climate change. The report informs management decisions at a local level through monitoring site conditions and developing site-specific sea-level rise response models. The program also spoke with managers, biologists, tribes, and other stakeholders in order to facilitate communication concerning the results of sea-level rise response models. In-person workshops were held with decision makers and stakeholders involved with six Pacific coast estuaries in order to discuss site-specific science results and manager needs.
Climate Change Impacts on Wave and Surge Processes in a Pacific Northwest Estuary
Cheng, T. K., D. F. Hill, J. Beamer, and G. García-Medina (2015), Climate change impacts on wave and surge processes in a Pacific Northwest (USA) estuary, J. Geophys. Res. Oceans, 120, 182–200, doi: http://dx.doi.org/10.1002/2014JC010268.
Total water levels (TWLs) within estuaries are influenced by tides, wind, offshore waves, and streamflow, all of which are uniquely affected by climate change. The magnitude of TWL associated with various return periods is relevant to understanding how the hydrodynamics of a bay or estuary may evolve under distinct climate scenarios. The coupled Advanced Circulation (ADCIRC) and Simulating Waves Nearshore (SWAN) model was used to simulate wave and water elevation conditions within Tillamook Bay, OR, USA for two long-term scenarios; 1979–1998 and 2041–2060. The model output provided multidecadal time series of TWLs for statistical analysis. Latitudinal and seasonal gradients were found in TWLs associated with varying return periods for both the hindcast and forecast. Changes in TWLs from hindcast to forecast included the sea level rise component and were also modulated by changes in boundary conditions.
Global Warming May Boost Dead Zones in Oceans
Moffitt, S.E., Moffitt, R.A., Sauthoff, W., Davis, C.V., Hewett, K, Hill, T.M. 2015. Paleoceanographic Insights on Recent Oxygen Minimum Zone Expansion: Lessons for Modern Oceanography. PLoS ONE 10(1): e0115246. doi: http://dx.doi.org/10.1371/journal.pone.0115246
Researchers at the University of California, Davis, analyzed ocean sediment data and found that the last time the planet experienced a major temperature change, oxygen levels fell sharply along the continental margins in the eastern Pacific Ocean. This discovery raises concerns about whether current warming trends will make regions of the oceans uninhabitable for marine life that need oxygen for survival. Major changes in the distribution of oxygen are already underway in the modern ocean. Modern losses of dissolved oxygen have been detected in every ocean basin by oceanographers and modern instrumentation.
Climate mediates hypoxic stress on fish diversity and nursery function at the land–sea interface
Hughes, B.B.; Levey, M.D.; Fountain, M.C.; Carlisle, A.B.; Chavez, F.P. and Gleason, M.G. 2015. Climate mediates hypoxic stress on fish diversity and nursery function at the land-sea interface. PNAS 112(26) 8025-8030.
Researchers have found that climate can be a powerful moderator of coastal hypoxia, but the effects of climate change are hard to predict. In the future water will be warmer, and warm water holds less oxygen than cold water. Climate change is also likely to influence the frequency and intensity of El Niño events, but exactly how is still unclear. Reducing the stress caused by nutrient enrichment and hypoxia will improve the resilience of the ecosystems and help buffer the effects of climate change. Opportunities for improving coastal land management practices are numerous and varied. Conservation groups and land managers can partner with farmers and fishers to manage nutrient applications, restore or rebuild wetlands that will reduce nutrient levels in agricultural discharge water.
New report explaining ocean warming
The International Union for Conservation of Nature recently released a comprehensive report on the potential impacts of ocean warming on nature and humans. Titled “Explaining ocean warming: Causes, scale, effects, and consequences,” the report synthesizes the understood impacts that warming will have across all marine life, from microorganisms to marine mammals. A team of 80 international scientists collaborated to produce this synthesis. Their goal was to report the understood consequences of a warming ocean and the known gaps in scientific knowledge as a call for further research.
Sea Level Rise Modeling Handbook
Doyle, T.W., Chivoiu, Bogdan, and Enwright, N.M., 2015, Sea-level rise modeling handbook—Resource guide for coastal land managers, engineers, and scientists: U.S. Geological Survey Professional Paper 1815, 76 p., http://dx.doi.org/10.3133/pp1815.
The USGS has released a resource guide on sea level rise modeling for coastal land managers, engineers, and scientists. The handbook defines, categorizes and builds criteria around the large amount of data, methods, and models concerning hindcasting and forecasting sea-level rise impacts. In doing this, the authors mean to aid in the appropriate application of coastal models for the broad range of disciplines seeking to understand the effects of sea-level rise. Depending on the research question being asked, scientists, land managers and engineers can use this handbook in order to apply the appropriate tools and models with specific parameters, and spatial and temporal scales.
Record-setting bloom of toxic algae in North Pacific
Algal blooms are the rapid accumulation of phytoplankton, or microscopic marine plants, and can be toxic depending on the presence of certain toxin-producing species. The North Pacific has been experiencing a record-breaking algal bloom along its coastal waters. The bloom has spread from the Aleutian Islands all the way to the coasts of southern California and continues to expand. Some species of phytoplankton produce neurotoxins that get passed up the food chain and become harmful toward marine mammals and humans. Along these impacted coasts a large number of marine mammal deaths have been reported. The cause of deaths is currently being investigated. Additionally, extremely high levels of domoic acid, a type of toxin produced by a group of phytoplankton called Pseudo-nitzschia, have been detected along Washington and Oregon causing shellfish and some fisheries industries to close. Due to the potential damage such major algal blooms can have on marine wildlife and the economies that rely on them, NOAA has awarded funding to further monitor and study the bloom and its impacts.
Declining calcification of the California mussel
Pfister CA, Roy K, Wootton JT, McCoy SJ, Paine RT, Suchanek TH, Sanford E. 2016. Historical baselines and the future of shell calcification for a foundation species in a changing ocean. Proceedings of the Royal Society of London B 283: 20160392. http://dx.doi.org/10.1098/rspb.2016.0392
Evolutionary biologist Catherine Pfister and colleagues recently published a study examining historical changes in shell thickness of the California mussel (Mytilus californianus). The authors compared shell thickness of living mussel populations to that of archival collections and previous studies at two sites along the Washington coast, Tatoosh Island and Sand Point. The study found that shells of M. californianus in Washington State are significantly thinner today compared with conspecific individuals in middens dating from 1000 to 2500 years BP. Additionally, results from Tatoosh Island showed that total shell thickness and thickness per shell length were significantly lower in modern shells compared with archived shells from the 1970s. The authors identified ocean acidification, or the declining of ocean pH due to increased marine intake of carbon dioxide, as the likely explanation for these findings.
Homeowners Prepare for Climate Change Along the Oregon Coast
By 2100, depending on the local terrain, sea levels along the Northwest coast will rise by anywhere from less than half a meter (1.5 feet) to as much as one-and-a-half meters (4.5 feet), according to current research. This means that by century’s end, the Pacific is likely to inundate the coast by as much as 50 meters (164 feet) in some places. The conclusion is inescapable: the Northwest’s coastal communities are at risk. But Neskowin residents and others in Oregon’s Tillamook County aren’t letting the dire projections drown their hopes. Instead, they’re adapting. And they’re getting some help from the Pacific Northwest Climate Impacts Research Consortium (CIRC).
Ocean acidification may cause dramatic changes to phytoplankton
Dutkiewicz, S., Jeffrey Morris, J., Follows, M.J., Scott, J., Levitan, O., Dyhrman, S.T., Berman-Frank, I. 2015. Impact of ocean acidification on the structure of future phytoplankton communities. Nature Climate Change. Doi: 10.1038/nclimate2722
The uptake of carbon dioxide in the oceans has resulted in a drop of the global average pH from 8.2 to 8.1. By 2100, it is projected to drop further to around 7.8, which is significantly lower than any pH levels seen anywhere in open ocean marine communities around the world. The authors of this study show how ocean acidification by 2100 is projected to affect phytoplankton. Phytoplankton species are projected to exhibit a wide range of responses: some will die out, while others will flourish. Thus the balance of plankton species will be fundamentally altered. Some species will even grow faster than previously, while others will be significantly harmed, perhaps going extinct. Warming temperatures will also significantly affect the locations of phytoplankton. Many species will shift toward the poles as the planet warms. However, the most significant changes will occur from ocean acidification.
Atmospheric rivers impact sea water levels
Khouakhi, A., and G. Villarini. 2016. On the relationship between atmospheric rivers and high sea water levels along the U.S. West Coast, Geophys. Res. Lett., 43, doi:10.1002/2016GL070086.
A newly published study from the University of Iowa examined the relationship between atmospheric rivers and sea level along the continental U.S. Pacific Coast. Atmospheric rivers are narrow river-like regions of atmosphere with high water vapor content and strong winds. This study contains some of the first research to examine the relationship between atmospheric rivers and sea level. Using hourly sea level time series from 15 tide gauges, the authors found that atmospheric rivers are associated with 15% to 50% of the annual sea level maxima before removing tidal oscillations. The authors concluded that atmospheric rivers are a prominent driver in extreme sea water level distribution.
NOAA Turning the High Beams on Ocean Acidification
NOAA is providing a grant of $1.4 million over three years to help shellfish growers and scientific experts work together to expand ocean acidification (OA) monitoring in waters that are particularly important to Pacific coast communities, such as in oyster hatcheries and coastal waters where young oysters are grown. Part of this grant will be used to increase the number of shellfish growers and hatchery owners that have the capability to detect ocean changes. This will be achieved by training individuals how to monitor OA and encouraging them to work together in communities of practice, developing more accurate and affordable sensors to measure these changes, and making the data from these sensors readily accessible.
Macroscale patterns in body size of intertidal crustaceans provide insights on climate change effects
Jaramillo, E.; Dugan, J.E.; Hubbard, D.M.; Contreras, H.; Duarte, C.; Acuña, E. & Schoeman, D.S. 2017. Macroscale patterns in body size of intertidal crustaceans provide insights on climate change effects. PloS one, 12(5), p.e0177116. DOI: https://doi.org/10.1371/journal.pone.0177116
A team of scientists analyzed the body size of the crustaceans that comprise the majority of intertidal abundance and biomass on sandy beach ecosystems of the Pacific coasts of Chile and California. Because climate change-induced changes in sea surface temperatures scales strongly with growth and fecundity for many ectotherms, researchers analyzed the contemporary macroscale patterns in body size of these crustaceans. They found that sea surface temperature was a strong predictor of body size in all species, and that beach characteristics were subsidiary predictors. They note that, because of the consistency of results for body size and temperature across species with such different life histories, this research suggests that predictions of ecosystem responses to changes in temperature may potentially be generalized, which has important implications for coastal conservation.
The Voice of the Canaries in the Coal Mine: West Coast Shellfish Industry Responds to Ocean Acidification
Mabardy, R. A., Waldbusser, G. G., F Conway, F., and Olsen, C.S. “Perception and Response of the U.S. West Coast Shellfish Industry to Ocean Acidification: The Voice of the Canaries in the Coal Mine,” Journal of Shellfish Research, 34(2):565-572. 2015, doi: http://dx.doi.org/10.2983/035.034.0241
The U.S. West Coast shellfish industry continues to be one of the first to feel the effects of climatic extremes, and therefore knows the economic damage these events can have on its livelihood. Ocean acidification was pegged as the dominant factor that led to past declines in shellfish populations, so scientists from Oregon State University decided to survey the shellfish industry to measure their concern toward this indirect effect of increased carbon dioxide in the atmosphere. Scientists surveyed 86 members of shellfish industries stationed in either Washington, Oregon, or California. Over half of the participants responded that they had already felt the negative effects of ocean acidification, and of those respondents, nearly all said they were "extremely" to "very concerned" about the phenomenon. The study also found that despite 80% of the shellfish industry believing ocean acidification to be a real problem, only 20% of the U.S. public seems to agree. This disparity in level of concern mirrors the disparity of those who have already felt its negative effects; a much smaller percentage of the U.S. general public have been directly affected by ocean acidification. Thus, the West Coast shellfish industry has become the voice of the canaries in the coal mine, warning others of this projected global problem.
Adapting to Climate Change on the Oregon Coast
Oregon Shores Conservation Coalition. Adapting to Climate Change on the Oregon Coast: A Citizen’s Guide (March 2015).
The Climate Adaptation Knowledge Exchange (CAKE) has released a new report on adapting to climate change on the Oregon coast. CAKE is managed by the non-profit organization EcoAdapt and aims to build a shared knowledge base for natural resource management in the face of climate change. The report, titled ‘A Citizen’s Guide to Climate Change on the Oregon Coast’, was published in March 2015 and aims to serve as introduction to information and the state of the science on climate change effects on the Oregon coast. It is also intended to serve as a resource for citizens that want to help their communities in adaptation efforts. Part One of the guide provides an overview of topics on climate change adaptation on the Oregon coast. It provides a number of hyperlinks so that readers can find more online resources and articles for further information. Part Two of the guide contains a set of papers written by various experts in science, law and policy in Oregon. The papers were commissioned by Oregon Shores Conservation Coalition in 2012 and also contain a number of additional resources. The guide is available for free at the link below.
Ocean acidification study offers warnings for marine life, habitats
Sunday et al. 2017. Ocean acidification can mediate biodiversity shifts by changing biogenic habitat. Nature Climate Change, 7: 81-85. doi:10.1038/nclimate3161
An international team of scientists, including University of Washington professor Terrie Klinger, recently published a comprehensive study of the effects of ocean acidification on the structure and complexity of living habitats such as coral reefs, kelp forests and seagrasses. This study is unique in that it reports on the effects to habitats as a whole rather than individual species. Analyses from this multidimensional report predict declines in the biodiversity of species in coral reefs, mussel beds and kelp forests, however an increase in the biodiversity of species from seagrass habitats. Predictions of decreased biodiversity were supported by available in situ data, however lacked evidence for the predicted enhancement of seagrass biodiversity.
Response of pink salmon to CO2-induced aquatic acidification
Ou, M., Hamilton, T. J., Eom, J., Lyall, E. M., Gallup, J., Jiang, A & Brauner, C. J. (2015). Responses of pink salmon to CO2-induced aquatic acidification. Nature Climate Change, 5(10), 950-955.
A recent study published by Nature examines the related effects of ocean acidification on freshwater ecosystems. Specifically, the authors assess the impacts of CO2-induced acidification on the early development of pink salmon. Using predicted future levels of CO2 with a naturally fluctuating CO2 treatment, the researchers measured growth, routine and maximum metabolic rate, levels of anxiety, and olfactory and anti-predator responses to conspecific alarm cues in various stages of development. The study concluded that acidification produced negative effects on the growth, metabolism, olfactory responses, and anti-predator behavior in pink salmon during freshwater development and post-seawater entry. This study extends the risk of ocean acidification to freshwater ecosystems and highlights the importance of climate change mitigation.
Key Lessons for Incorporating Natural Infrastructure into Regional Climate Adaptation Planning
Langridge et al., Ocean & Coastal Manage, Volume 95, July 2014, Pages 189–197, DOI: 10.1016/j.ocecoaman.2014.03.019
A new article in Ocean & Coastal Management details a collaborative process in two coastal California counties to account for the role of natural infrastructure in climate adaptation planning.
Juvenile starfish rebound in pockets of the Pacific
Seastar populations along the coast of western North America experienced a drastic two-year decline due to an epidemic wasting disease. However, according to an article by the Associated Press, Oregon State University’s marine biologist Bruce Menge and his colleagues have recorded a massive rebound of larval seastars since 2015. The cause of the epidemic and this sudden boom in seastar population remains largely unknown.
Impact of increasing CO2 emissions on the world’s oceans
Nagelkerken, I., & Connell, S. D. (2015). Global alteration of ocean ecosystem functioning due to increasing human CO2 emissions. Proceedings of the National Academy of Sciences, 201510856.
Rising anthropogenic CO2 emissions are anticipated to drive change to ocean ecosystems, but quantitative analyses of this understanding is limited. The authors of this study, Ivan Nagelkerken and Sean D. Connell, compiled 632 published experiments and quantified the direction and magnitude of ecological change resulting from ocean acidification and warming. They found that primary production by temperate, noncalcifying plankton increased with elevated temperature and CO2, whereas tropical plankton productivity decreased from acidification. In addition, secondary production decreased with acidification in both calcifying and noncalcifying species. In summary, Nagelkerken and Connell showed that ocean acidification and warming increased the potential for an overall simplification of ecosystem structure and function with reduced energy flow among trophic levels and little scope for species to acclimate.
New method for studying coastal soil erosion could help lessen climate change effects
Hursta, M.D., Rood, D.H., Ellis, M.A., Anderson, R.S., Dornbusch, U. 2016. Recent acceleration in coastal cliff retreat rates on the south coast of Great Britain. Proceedings of the National Academy of Sciences: 113(47): 13336-13341. doi: 10.1073/pnas.1613044113
Climate change-induced sea level rise and storm frequency increase are both factors that affect coastal erosion. In this new study, scientists examined the change in coastal erosion, or retreat rate, of the soft chalk cliffs on the southern coast of the United Kingdom. The study compared modern observations (150 year-long dataset) to historic retreat rates calculated using concentrations of 10Be on a coastal platform and a numerical model. The study quantified historical retreat rates of approximately 2-6 cm/yr compared to the modern retreat rates of 10-80 cm/yr. The authors concluded that this acceleration in retreat rate is likely due to anthropogenic exacerbation of cliff-front beach thinning.
Climate change and wind intensification in coastal upwelling ecosystems
Syndeman, W.J., M. García-Reyes, D.S. Schoelam, R.R. Rykaczewski, S.A. Thompson, B.A. Black, and S.J. Bograd. 2014. Climate change and wind intensification in coastal upwelling ecosystems. Science 4 July 2014: 345 (6192), 77-80. DOI:10.1126/science.1251635 http://cses.washington.edu/db/pubs/abstract831.shtml
The authors retrospectively examined the literature from 1990 – 2012 on wind intensification in four key eastern boundary current systems. Results indicate that the California, Humboldt and Canary systems show wind intensification when warm season or observational data are considered. For the Benguela system, only modeled year-round data were available, showing increasing winds. In contrast, the Iberian system showed weakening of winds. The positive trends for wind strengthening were more frequent in the warm season. Similarly, results based on observational data tend to support intensification more than results based on modeled data, which only increases in the California and in the Benguela systems. Within the current systems, stronger winds were associated with higher latitudes. Where winds intensify, stronger upwelling patterns could favor marine productivity by increasing nutrient inputs.
On Thin Ice: Combined Arctic Ice Observations Show Decades of Loss
Lindsay, R., & Schweiger, A. 2015. Arctic sea ice thickness loss determined using subsurface, aircraft, and satellite observations. The Cryosphere, doi: http://dx.doi.org/ 10.5194/tc-9-269-2015
University of Washington researchers compiled modern and historic measurements to get a full picture of how Arctic sea ice thickness has changed. The results, published in The Cryosphere, show a thinning in the central Arctic Ocean of 65 percent between 1975 and 2012. September ice thickness, when the ice cover is at a minimum, is 85% thinner for the same 37-year stretch. “The ice is thinning dramatically,” said lead author Ron Lindsay, a climatologist at the UW Applied Physics Laboratory. “We knew the ice was thinning, but we now have additional confirmation on how fast, and we can see that it’s not slowing down.” The study helps gauge how much the climate has changed in recent decades, and helps better predict an Arctic Ocean that may soon be ice-free for parts of the year.
Fish stocks are struggling to rebound
Britten, G.L., Dowd, M. and Worm, B., 2015. Changing recruitment capacity in global fish stocks. Proceedings of the National Academy of Sciences, 113(1), pp.134-139. doi: 10.1073/pnas.1504709112
Recently published in the Proceedings of the National Academy of Sciences, a new analysis finds that the ability of fish populations to reproduce and replenish themselves is declining across the globe. Gregory L. Britten, a doctoral student at the University of California, Irvine, and fellow researchers looked at data from a global database of 262 commercial fish stocks in dozens of large marine ecosystems across the globe. They say they've identified a pattern of decline in juvenile fish (young fish that have not yet reached reproductive age) that is closely tied to a decline in the amount of phytoplankton, or microalgae, in the water. While the aggregated data show global decline, the results varied when the researchers looked at plankton and fish reproduction declines in individual ecosystems. In the North Pacific, for example, there were no significant declines. But in other regions of the world, like Australia and South America, it was clear that the lack of phytoplankton was the strongest driver in diminishing fish populations.
Seaweed in the Spotlight
Ocean acidification is just one of the ways in which coastal communities are already feeling the effects of a changing global ocean. The potentially devastating ramifications have made it an urgent environmental and economic issue. A collaborative project led by the Puget Sound Restoration Fund in conjunction with NOAA and other partners, was just awarded $1.5 million by the Paul G. Allen Family Foundation to tackle the impacts of ocean acidification. The project looks to employ an unlikely hero: seaweed.
New research quantifies what’s causing sea level to rise
Purkey, S. G., G. C. Johnson and D. P. Chambers. 2014. Relative contributions of ocean mass and deep steric changes to sea level rise between 1993 and 2013. Journal of Geophysical Research: Oceans. DOI: 10.1002/2014JC010180 Online: http://www.skepticalscience.com/new-research-quantifies-sea-level-rise.html http://onlinelibrary.wiley.com/doi/10.1002/2014JC010180/abstract
Changes to sea level are mainly caused by thermal expansion of ocean waters as they heat, changes to the saltiness of water, and by an increase in ocean waters as ice melts and flows into the sea. The total annual sea level rise is about 3 mm per year – the question is, how much of that is from expansion and how much is from melting? This research found that amount of heating decreases with ocean depth but that every water layer, even the deepest waters, have contributed some to sea level rise. The authors also report that the sea level rise contribution from the layers 300-2000 meters is much more than previously reported.
Long-term sea level trends: Natural or anthropogenic?
Becker, M., M. Karpytchev, and S. Lennartz-Sassinek (2014), Long-term sea level trends: Natural or anthropogenic?, Geophys. Res. Lett., 41, doi:10.1002/2014GL061027
Detection and attribution of human influence on sea level rise are important topics that have not yet been explored in depth. We question whether the sea level changes (SLC) over the past century were natural in origin. SLC exhibit power law long-term correlations. By estimating Hurst exponent through Detrended Fluctuation Analysis and by applying statistics of Lennartz and Bunde , we search the lower bounds of statistically significant external sea level trends in longest tidal records worldwide. We provide statistical evidences that the observed SLC, at global and regional scales, is beyond its natural internal variability. The minimum anthropogenic sea level trend (MASLT) contributes to the observed sea level rise more than 50% in New York, Baltimore, San Diego, Marseille, and Mumbai. A MASLT is about 1 mm/yr in global sea level reconstructions that is more than half of the total observed sea level trend during the XXth century.
Storm wave study could help improve design of coastal defenses
Y. Watanabe, D. M. Ingram. Size distributions of sprays produced by violent wave impacts on vertical sea walls. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Science, 2016; 472 (2194): 20160423 DOI: 10.1098/rspa.2016.0423
An international team of scientists used a scaled-down version of a seawall to record patterns of spray after impact from waves. They used their observations to make a statistical model to calculate patterns of spray that they hope will help inform the design of future defense strategies like seawalls and other barricades.
Sediments control methane release to the ocean
Giuliana Panieri, Carolyn A. Graves, Rachael H. James. 2016. Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard. Geochemistry, Geophysics, Geosystems; 17 (2): 521 DOI: 10.1002/2015GC006153
A new study recently published in the journal Geochemistry, Geophysics, Geosystems examined geochemical characteristics of foraminifera, a marine protozoa, and other proxies as a record of methane seepage in four sediment cores from an area of ongoing ocean warming, offshore from western Svalbard, Norway. Foraminifera were used because their shells are extremely sensitive to environmental changes, so the authors were able to determine whether methane was released while their shells were forming or immediately after. The findings, however, showed no evidence of methane seepage in the Foraminiferal record. This lack of evidence implies that melting of gas hydrate is not the primary control on seafloor methane seepage on the upper continental margin, as is commonly accepted. Rather, the authors suggest that sediment lithology may be the dominant control of methane release, and conclude that more research must be done to further our understanding of methane seepage under future warming conditions.
Obama Orders Federal Agencies to Account for Rising Seas in their Investments
The Obama administration has ordered federal agencies to account for rising seas and stronger storms when making grants and building infrastructure, one of the most definitive steps it has yet taken to adapt the country to a changing climate. In an executive order, Obama implemented a new Federal Flood Risk Management Standard that provides agencies with three options for determining where it is safe to invest federal dollars. They can use data and methods based on (1) "best- available, actionable climate science"; (2) they can require buildings to be 2 feet above the 100-year flood elevation; or (3) they can require that infrastructure is built to at least the 500-year floodplain. Currently, the majority of federal investment is based on the 100-year floodplain.
Climate-linked Mechanisms Drive Spatial and Temporal Variation in Eelgrass Growth and Assemblage Structure in the Pacific Northwest
Thom, R., Southard, S. and Bourde, A. 2014. Climate-linked Mechanisms Driving Spatial and Temporal Variation in Eelgrass (Zostera marina L.) Growth and Assemblage Structure in the Pacific Northwest Estuaries, USA. Journal of Coastal Research. 68:1-11. DOI: 10.2112/SI68-001.1
Using a combination of field data and laboratory experiments, the authors have shown that variations in water temperature, mean sea level, and stress from drying appear to drive spatial and temporal patterns in eelgrass. Complicated interactions among these variables make it difficult to predict the effects of climate change on this important resource. However many characteristics of eelgrass make it a suitable indicator of the effects of climate variation on marine and estuarine ecosystems.
Pacific sea level predicts global temperature changes
Peyser, C.E., Yin, J., Landerer, F.W., & Cole, J.E. 2016. Pacific sea level rise patterns and global surface temperature variability. Geophysical Research Letters, 43. doi:10.1002/2016GL069401.
A new report led by geoscientists from the University of Arizona examined the relationship between changes in sea level in the western Pacific Ocean and global temperature changes. The authors first used global climate models to identify and quantify the relationship between these two phenomena, and then used the calculated correlation to better understand sea level changes measured by satellites. The authors observed that the rise in global temperatures slowed during periods of rapid sea level rise in the western Pacific and quickened during periods when sea level dropped in the western Pacific but rose in the eastern Pacific. The east-west contrast in sea level along the Pacific acts as a natural sea-saw, and is now understood to oscillate between dampening and exacerbating anthropogenic changes in global temperature.
Flooding’s impact on wetlands measurable via low-cost approach
A new method for studying the impacts of sea-level rise on wetlands was recently published in Methods in Ecology and Evolution. Scientists designed an in situ, low-cost enclosure called a weir that can realistically simulate low, intermediate, and high level flooding on coastal wetlands. The particular design of weirs enables scientists to manipulate its water level and drainage rate, making it functional under both high and low tides. The lead author, Dr. Julia Cherry, is interested in combining this design with another approach that involves replicating the natural environment (the mesocosm approach). Dr. Cherry sees this combination as a potentially powerful tool for understanding the impacts of a rising sea level on wetlands.
Reanalysis of Twentieth-Century Sea Level Rise
Hay, C.C., Morrow, E., Kopp, R.E., Mitrovica, J.X. 2015. Probabilistic reanalysis of twentieth-century sea-level rise. Nature, 517, 481-484. http://dx.doi.org/10.1038/nature14093
Estimating and accounting for twentieth-century global mean sea-level rise (SLR) is necessary for characterizing current and future human-induced SLR. Previous studies of tide gauge records concluded that global mean sea-level (GMSL) rose at a rate of 1.6-1.9 mm/year over the twentieth-century. To account for this rate, scientists have added measurements of melt water from land ice, ocean thermal expansion, and changes in land water storage and their total has consistently fallen short. In a paper published by Nature, Harvard and Rutgers scientists attempt to resolve the discrepancy by revisiting estimates of twentieth-century GMSL rise using probabilistic techniques. Researchers conclude that the GMSL rate from 1901-1990 was actually 1.2 ± 0.2 mm/year (compared to the previously established rate of 1.6-1.9 mm/year). While this research does help close the gap between model estimated SLR and actual measurements of SLR over the twentieth-century, the research also confirms the recent acceleration of the rate of SLR from 1993-2010.
Millions Projected to be at Risk from Sea Level Rise in the U.S.
Hauer, M. E., Evans, J. M., & Mishra, D. R. (2016). Millions projected to be at risk from sea-level rise in the continental United States. Nature Clim. Change, advance online publication. Retrieved from http://dx.doi.org/10.1038/nclimate2961
In this study, scientist Mathew Hauer from the University of Georgia and colleagues attempt to address two key questions regarding sea level rise: 1) how many people are at risk from sea level rise, and 2) what areas in the US are projected to experience the greatest amount of population exposure to sea level rise? To answer these questions, they draw on the NOAA sea level rise data sets for 22 coastal states, including the District of Columbia. Two scenarios are studied; one scenario with 1.9 m of sea level rise and the second with 1.8 m of sea level rise. For the 1.8 m scenario, they find that 13 million people in the US are at risk of being affected. This includes 11, 178 people in Washington and 4, 374 in Oregon, and for higher sea level rise scenario, 11, 178 in Washington and 8, 985 in Oregon. The authors suggest that if measures are not enacted that would mitigate sea level rise, large population migrations could result as a consequence of sea level rise by the end of the twenty-first century.
Natural variations playing an important role in sea level rise:
Wendel, J. 2014. Sea levels changing in response to natural variations, Eos Trans. AGU, 95(48), 452. doi: http://dx.doi.org/10.1002/2014EO480009
Scientists have widely accepted that sea level has been rising over the past one hundred years due to anthropogenic activities that warm the planet and melt land-locked ice. If green house gas emissions continue at their current rate, models suggest that sea level rise will continue at an accelerated rate. However, despite the emphasis on anthropogenic factors as a driving force of sea level rise, Dangendorf et al. posit that natural variation could be playing a larger role in SLR than previously thought. After analyzing 138 years of tidal gauge and ocean reanalysis data the authors found that natural variation caused random and persistent sea levels changes spanning several decades. These natural variations could incorrectly be interpreted as an acceleration of the rate of sea level rise. Therefore, future sea level rise could be higher or lower than predicted levels because of deviations arising from natural variability.
El Nino and La Nina to Exacerbate Coastal Hazards along Pacific Coast
Barnard PL, Short AD, Harley MD, Splinter KD, Vitousek S, Turner IL, Allan J, Banno M, Bryan KR, Doria A, Hansen JE, Kato S, Kuriyama Y, Randall-Goodwin E, Ruggiero P, Walker IJ, Heathfield DK (2015) Coastal vulnerability across the Pacific dominated by El Nino/Southern Oscillation. Nature Geoscience. doi: 10.1038/ngeo2539
A new study analyzing coastal data from across the Pacific Ocean basin from 1979-2012 to determine if patterns in coastal change could be connected to climate cycles. Data was culled from US and Canada beaches along with beaches in Japan, Australia, New Zealand and Hawaii. Previous studies had looked at local and regional coastal patterns, but this was the first study to aggregate similar data from across the Pacific. The authors found that all regions were affected during both El Nino and La Nino years. If the US mainland west coast and Canada felt the effects of El Nino, including larger waves, different wave directions and higher water levels and erosion, Hawaii and northern Japan felt the same effects, while New Zealand and Australia experienced the opposite effects. The reverse occurred for La Nina years. The authors concluded that the projected increase of severe El Nino and La Nina events would result in an increase in storm events that cause extreme flooding along the Pacific coast and erosion. Up until now, it had been difficult for researchers to isolate the effects of large-scale climate patterns from other smaller-scale local and regional climate drivers. Bringing together a large spatial and temporal dataset made it possible to isolate ENSO patterns. Mitchell Harley, a researcher at UNSW Australia and coauthor of the paper, stated that this study could help Pacific coastal communities to prepare for changing storm regimes that are driven by El Nino and La Nina events.
Climate Central launches a new online tool for exploring sea level rise and flood risks
Climate Central’s Program on Sea Level Rise launched a new interactive web tool this month. Their newly redesigned public sea level rise and coastal flood risk tool for the U.S. is called Surging Seas Risk Finder. The tool has several new features, including a streamlined user interface, downloadable figures, and a localized fact sheet.
New approach to projecting sea-level suggests higher coastal flooding potential
Goodwin, P., Haigh, I. D., Rohling, E. J. and Slangen, A. 2017. A new approach to projecting 21st century sea-level changes and extremes. Earth's Future. doi:10.1002/2016EF000508
Our understanding of future increases in flooding potential around the world's coastlines depends on projections of future global mean sea level (GMSL) rise. Yet, the two main approaches for projecting 21st century GMSL rise—i.e., process-based versus semi-empirical—give inconsistent results. This paper reports the results of a novel hybrid approach to GMSL projection. The projections from this hybrid approach were found to be consistent with the dominant process-based GMSL projections from the Climate Model Intercomparison Project phase 5 (CMIP5) ensemble. However, when observations were used to provide the historic constraints, the authors found higher ice-melt sensitivity and additional ensemble-mean GMSL rise of around 13–16 cm by the end of the century. They assess the impact of this additional GMSL rise on the increase in frequency of extreme sea level events for 220 coastal tide-gauge sites. Accounting for regional effects, they found a 1.5–8 times increase in the frequency of extreme sea-level events for their higher GMSL projections relative to CMIP5.
Marine reserves help mitigate against climate change
Callum M. Roberts, Bethan C. O’Leary, Douglas J. McCauley, Philippe Maurice Cury, Carlos M. Duarte, Jane Lubchenco, Daniel Pauly, Andrea Sáenz-Arroyo, Ussif Rashid Sumaila, Rod W. Wilson, Boris Worm, and Juan Carlos Castilla. In press. Marine reserves can mitigate and promote adaptation to climate change. PNAS, June 2017 DOI: 10.1073/pnas.1701262114
A new review, published in the Proceedings of the National Academy of Sciences, evaluated existing peer reviewed studies on the impact of marine reserves around the world. Authors conclude that Marine Reserves and Marine Protected Areas (MPAs) protect coasts from sea-level rise, storms and other extreme weather events; help offset climate-change induced declines in ocean and fisheries productivity; provide refuges for species as they adjust their ranges to changing conditions; and can help combat acidification. Reserves also can promote uptake and long-term storage of carbon from greenhouse gas emissions, especially in coastal wetlands, which helps reduce the rate of climate change. Currently, only 3.5 per cent of the ocean has been set aside for protection with just 1.6 per cent fully protected from exploitation. International groups are working to raise the total to 10 per cent by 2020, while delegates to the International Union for the Conservation of Nature's 2016 World Conservation Congress agreed that at least 30 per cent should be protected by 2030.
Changing El Ninos reduce stability of North American salmon survival rates
D. Patrick Kilduff, Emanuele Di Lorenzo, Louis W. Botsford, and Steven L. H. Teo, Changing central Pacific El Niños reduce stability of North American salmon survival rates, PNAS 2015 112 (35) 10962-10966; published ahead of print August 3, 2015, doi:10.1073/pnas.1503190112
Pacific salmon are a dominant component of the northeast Pacific ecosystem. In this new study, scientists from the Department of Wildlife, Fish and Conservation Biology, UC Davis, and Georgia Tech address the question of how recent changes in ocean conditions will affect populations of two salmon species (coho and Chinook). Since the 1980s, El Niño Southern Oscillation (ENSO) events have been more frequently associated with central tropical Pacific warming (CPW) rather than the canonical eastern Pacific warming ENSO (EPW). CPW is linked to the North Pacific Gyre Oscillation (NPGO), whereas EPW is linked to the Pacific Decadal Oscillation (PDO). Here the authors show that both coho and Chinook salmon survival rates along western North America indicate that the NPGO, rather than the PDO, explains salmon survival since the 1980s. The observed increase in NPGO variance in recent decades was accompanied by an increase in coherence of local survival rates of these two species, increasing salmon variability via the portfolio effect. The portfolio effect is an ecological phenomenon where increased biodiversity leads to increased ecological stability. Such increases in coherence among salmon stocks are usually attributed to controllable freshwater influences such as hatcheries and habitat degradation, but the unknown mechanism underlying the ocean climate effect identified here is not directly subject to management actions.
Detailed map of acidifying oceans
Researchers from Columbia University have released the most detailed map to date of where on Earth ocean acidification is hitting the hardest. The map represents four decades’ worth of data. It shows that ocean pH fluctuates most in colder waters, including those off Alaska and the Pacific Northwest. Here massive plankton blooms in the spring and summer absorb carbon dioxide in the water, raising pH and causing seawater acidity to fall. In winter, the upwelling of CO2-rich water from the deep ocean causes surface waters to become more acidic.
Landmark global scale study reveals potential future impact of ocean acidification
Calosi, P., Melatunan, S., Turner, L.M., Artioli, Y., Davidson, R.L., Byrne, J.J., Viant, M.R., Widdicombe, S. and Rundle, S.D., 2017. Regional adaptation defines sensitivity to future ocean acidification. Nature Communications, 8, p.13994.
A team of scientists from Quebec and the United Kingdom analyzed metabolic behaviors in an intertidal snail (Littorina littorea) to better understand the impact of ocean acidification on a species with wide latitudinal range. The team collected snails from six different populations along the European coast that represented variation in water temperature (warm temperate, cold temperate and subpolar). They then placed the snails in a range of pH conditions and examined their metabolic responses. They found that snails from the limits of the species temperature range exhibited the most shell dissolution and metabolic change. The snails from cold temperate regions exhibited an increase in their metabolic rate which they used to maintain their growth and physiology to a better level than the other populations from the species’ range limits. The authors concluded by emphasizing the need to study multiple populations of the same species in order to build a comprehensive projection of species response to environmental forcings.
Severe erosion on U.S. West Coast during 2015–16 El Niño
Barnard, P.L., Hoover, D., Hubbard, D.M., Snyder, A., Ludka, B.C., Allan, J., Kaminsky, G.M., Ruggiero, P., Gallien, T.W., Gabel, L. and McCandless, D. In press. Extreme oceanographic forcing and coastal response due to the 2015–2016 El Niño. Nature Communications, 8. DOI:10.1038/ncomms14365
According to U.S. Geological Survey scientists and colleagues, the El Niño event from 2015-2016 was one of the most powerful of the last 145 years. Researchers investigated 29 beaches that spanned from southern California to Washington and found that winter erosion reached the highest levels ever recorded. Winter wave energy equaled or exceeded the measured historical maxima across the US West Coast and shorelines retreated beyond previously measured landward extremes in many areas. Researchers highlight that when planners assess coastal hazard vulnerability, it is important to consider the impacts of extreme El Niño events at different spatial and temporal scales.
USGS Coastal Change Hazard Portal
This tool gives you access to exploring coastal hazard risks information along America's coasts at varied scales, from local areas of interest to national scope. It was developed with “agile software,” so you can overlay other geographic information easily without the need for GIS programs. Pick your favorite coastal location, type in the name, zoom in, and explore historic shorelines, rates of shoreline change, sea-level rise, forecasts related to long-term change, the Coastal Vulnerability Index and more. Video: Tutorial demonstration of how to use the USGS Coastal Change Hazards Portal: https://www.youtube.com/watch?v=ZvlITDs9PII
New 13-year study tracks effects of changing ocean temperature on phytoplankton
K. R. Hunter-Cevera, M. G. Neubert, R. J. Olson, A. R. Solow, A. Shalapyonok, H. M. Sosik. Physiological and ecological drivers of early spring blooms of a coastal phytoplankter. Science, 2016; 354 (6310): 326 DOI: 10.1126/science.aaf8536
Scientists at the Woods Hole Oceanographic Institution (WHOI) used seawater samples collected continuously for 13 years by an automated sensor known as “Flow Cytobot” to study how changes in ocean temperature affect a key species of phytoplankton. They found that rising ocean temperatures caused annual blooms of Synechococcus to occur up to four weeks earlier than usual because their cells divided faster in warmer conditions. Shifts like this could impact marine ecosystems worldwide by affecting the livelihoods of larger species like fish, whales, and birds. The flow cytobot used in this study was located at Martha's Vineyard Coastal Observatory (MVCO), a small observatory stationed just off the Massachusetts island's coast. Much larger ocean observatories are currently being built off the US Pacific and Atlantic coasts, and in other locations worldwide. These new networks may enable similar studies in the future, offering a detailed look at ocean ecosystems around the globe.
Seagrass Genome Reveals Angiosperm Adaptation to Life in a Marine Environment
Olsen, J. L., Rouzé, P., Verhelst, B., Lin, Y.-C., Bayer, T., Collen, J., et al. 2016. The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea. Nature, advance on. Retrieved from http://dx.doi.org/10.1038/nature16548
A recent study published in Nature reported the genome of Zostera marina, the first marine angiosperm to be fully sequenced, according to the authors. The sequenced genome exposes the adaptations angiosperms have undergone in order to survive in their marine environment. Many genomic losses were found, including the genes regulating stomatal structure, UV protection, and other structural and physiological functions. Among the discovered gains in its genome were functions that enable angiosperms to adjust to higher salinity as well as maintain ion homeostasis in a marine environment. The article concluded by suggesting the importance of this sequenced genome as a resource both for understanding how marine ecosystems will adapt to future climate change, as well furthering evolutionary biology of plant adaptation capabilities.
NOAA Study Shows Oysters, Mussels have Low Levels of Disease, Parasites
NOAA has released its first-ever long term report of the national distribution of parasites and disease in mussels and oysters, concluding that there was no general threat to oyster and mussel population in the nation’s coastal waters at the time of the study, despite some locations along the Gulf of Mexico and West Coast with elevated rates of parasite infection and disease. This information is vital for determining degrading conditions as environmental stressors, including climate change and other natural and human-caused disasters, continue to impact coastal resources.
Ocean 'blob' of warm water bringing poor food for B.C. wild salmon
A University of Victoria oceanographer studying the so-called "warm blob" of water off the B.C. coast has observed unusual, "squishy" visitors from the south — and that could be bad news for young salmon. John Dower, who just returned from a research cruise north of Vancouver Island, said he saw remarkably high amounts of tiny animals called zooplankton in the "blob," a huge mass of ocean water about 2 degrees warmer than normal. And the varieties he saw are normally found off northern California — not Canada.
Washington’s Island County gets an advance look at future sea levels
Coastal hazard specialist and Washington Sea Grant researcher, Ian Miller, recently completed a comprehensive survey of the future risk of sea level rise to Island County, Washington. Miller combined historical data from three GPS stations on Whidbey Island and four tide gauges around Island County as well as previously published research to project future scenarios of varying extremes for the coastal health of Island County. The report found that sea level is likely to rise approximately 5.9 feet around Whidbey and Camano islands by 2150. Using this data, manager of Island County’s salmon recovery program Dawn Pucci was able to locate five areas within the county that could experience major flooding in the future, and therefore should be prioritized as restoration project sites. These areas include Crescent Harbor, Crockett Lake, Moran’s Beach, and Useless Bay on Whidbey Island, and Livingston Bay on Camano Island. Ian Miller and Island County managers see this report as the first step toward obtaining confident projections of future risks to the islands. One key factor that influences the intensity of coastal hazards and is currently a weak point in the study’s data is wave behavior during storm surges. The advancement and continuation of this work will be implemented through a National Oceanic and Atmospheric Administration’s Office for Coastal Management grant that will eventually build a comprehensive report of the entire Washington coast.
Current challenges of water quality criteria for an acidifying ocean
Stephen B. Weisberg, Nina Bednaršek, Richard A. Feely, Francis Chan, Alexandria B. Boehm, Martha Sutula, Jennifer L. Ruesink, Burke Hales, John L. Largier, Jan A. Newton. 2016. Water quality criteria for an acidifying ocean: Challenges and opportunities for improvement. Ocean & Coastal Management. vol. 126 p. 31-41. doi:10.1016/j.ocecoaman.2016.03.010
The West Coast Ocean Acidification and Hypoxia Science Panel has released a new publication assessing the current dissidence between the scientific criteria for researching the effects of ocean acidification and the criteria laid out in the Clean Water Act 303(d) for classifying bodies of water as impaired. The authors discuss the scientific challenges in classifying impairment for both pH and biological criteria. First, pH criteria is challenging because the current acceptable range includes acidity levels that have been known to cause significant ecological damage. Many states also discuss pH change as relative to a natural standard which has been difficult to define because of the lack of coastal monitoring data. In addition to pH science, the authors discussed the challenges facing biological research due to the difficulty in deciphering the specific phenomena causing biological declines. Without sufficient coastal monitoring of both pH levels and biological criteria, the authors stress the challenges scientists face in pinpointing ocean acidification effects. The authors concluded with proposals for improving the criteria in the Clean Water Act 303(d).
When dams come down, salmon and sand can prosper
The decision to undam a river is usually based in the desire to bring back migratory species, like salmon, to the river’s ecosystem. However, the removal of dams on the Elwha River in northern Washington is demonstrating that the release of formerly dammed-up sediment can be equally desirable. Scientists from the USGS, National Park Service, and the Lower Elwha Klallam Tribe have observed the rebuilding of an estuary and coast that had been gradually eroding since the dams were built in the early 20th Century. Millions of cubic yards of sediment that would have armored the Washington coast was instead accumulating behind the dams. Once these dams were removed, this sediment began to travel toward the river’s mouth, and its delta has since extended hundreds of meters toward the sea. This project has demonstrated the benefit of dam removals to other regions along the western coast of North America, particularly the California coast, which is suffering from large amounts of erosion. Many environmental lawyers and legal scholars are proponents of expanding this project to other dammed rivers, arguing that beaches have “sand rights,” or the right to sand that would naturally flow to them without human obstruction. Yet some are wary of the effects that the recent drought may have on river flow – the ability for sediment to move down a river may decrease with drought. While some are concerned, the consequence of removing dams in these other regions remains to be seen.
Tracking U.S marine fish populations as climate changes
Developed by NOAA Fisheries and Rutgers University, OCEANADAPT is a web tool designed to provide distribution data on nearly 650 species of U.S fish and invertebrates important for commercial and recreational fishing. Marine fish and vertebrate populations are responding to changing ocean conditions by shifting their distributions northward to cooler waters. OCEANADAPT is a valuable tool for fishermen, managers, scientists, and fishing communities tracking and evaluating the distribution of marine fish and other species with changing climate and ocean conditions.
Helping Communities Understand Future Coastal Hazards: USGS Coastal Processes Team develops a publicly available coastal storm modeling system for California residents
On the west coast of the United States, the USGS Pacific Coastal and Marine Science Center’s Coastal Processes Team, led by Patrick Barnard and a group of 10 modelers, geologists, engineers, and oceanographers, has developed the Coastal Storm Modeling System (CoSMoS) to help the 20 million residents of California coastal communities understand their vulnerabilities from storms and sea-level rise. CoSMoS is a state-of-the-art modeling system that models all the relevant physics of a coastal storm (for example, tides, waves, and storm surge), which are then scaled down to local flood projections. Rather than relying on historic storm records, CoSMoS uses wind and pressure from global climate models to project coastal storms under changing climatic conditions. Projections of multiple storm scenarios (daily conditions, annual storm, 20-year- and 100-year-return intervals) are provided under a suite of sea-level rise scenarios ranging from 0 to 2 meters (0 to 6 feet), along with a catastrophic 5-meter (16-foot) scenario. This allows users to manage and meet their own planning horizons and specify degrees of risk tolerance.
Ocean acidification alters the response of intertidal snails to a key sea star predator
Jellison, B. M., Ninokawa, A. T., Hill, T. M., Sanford, E., & Gaylord, B. (2016). Ocean acidification alters the response of intertidal snails to a key sea star predator. Proceedings of the Royal Society B: 283(1833), 20160890. doi:10.1098/rspb.2016.0890
Researchers examined how ocean acidification alters the behavioral response of a prey species, the black turban snail (Tegula funebralis) to an iconic predator, the sea star (Pisaster ochraceus) within the rocky intertidal zone of the temperate eastern Pacific Ocean. Researchers assessed interactions between these species at 16 discrete levels of pH, quantifying the full functional response of Tegula under present and near-future ocean acidification conditions. They found that snails showed fewer anti-predator behaviors at low pH and spent less time in refuge locations. These results suggest that there is a strong potential for ocean acidification to create cascading community-level shifts within the ecosystem.
Climate change already accelerating sea level rise
Fasullo, J.T., Nerem, R.S., Hamlington, B. 2016. Is the detection of accelerated sea level rise imminent? Scientific Reports 6: 31245 DOI: 10.1038/srep31245
Global climate simulations project sea level to rise at an accelerating rate, however sea level has steadily risen at approximately 3mm per year since satellite observations began in 1993. A recent report published in Nature Scientific Reports analyzed the internal climate variability that has kept the rate of sea level rise consistent since the early 1990s, and found that the eruption of Mount Pinatubo in 1991 is most likely responsible. The volcanic eruption was a temporary cooling source for the planet and has since masked the impact of global warming on sea level rise. The research team found that Pinatubo’s eruption caused the sea levels to drop by approximately 6 mm, and this was just before the first satellites began recording observations. John Fasullo, a scientist with the National Center for Atmospheric Research and lead author, said in an interview, “Now that the impacts of Pinatubo have faded, this acceleration should become evident in the satellite measurements in the coming decade, barring another major volcanic eruption.”
Sea Change - 2015-2025 Decadal Survey of Ocean Sciences
Ocean science connects a community of scientists in many disciplines - physics, chemistry, biology, geology and geophysics. Comprehensive understanding of the global ocean is fundamental to forecasting and managing risks from severe storms, adapting to the impacts of climate change, and managing ocean resources. In the United States, the National Science Foundation (NSF) is the primary funder of the basic research, which underlies advances in our understanding of the ocean. This report addresses the strategic investments necessary at NSF to ensure a robust ocean scientific enterprise over the next decade.
Decades of data on world’s oceans reveal a troubling oxygen decline
Ito, T.; S. Minobe; M.C. Long; & C. Deutsch. 2017. Upper Ocean O2 trends: 1958-2015. Geophysical Research Letters, 44(9): 4214–4223 DOI: 10.1002/2017GL073613
Researchers at the Georgia Institute of Technology looked at more than 50 years of ocean data and found that oxygen levels began dropping in the 1980s as ocean temperatures began to climb. Falling oxygen levels in water have the potential to impact the habitat of marine organisms worldwide, and, in recent years, have led to more frequent "hypoxic events" that killed or displaced populations of fish, crabs and other organisms. Researchers anticipated that rising water temperatures would affect the amount of oxygen in the oceans, since warmer water is capable of holding less dissolved gas than colder water. But this study showed that ocean oxygen was falling more rapidly than the corresponding rise in water temperature. Results were published in the April issue of Geophysical Research Letters. The research team included researchers from the National Center for Atmospheric Research, the University of Washington-Seattle, and Hokkaido University in Japan.
Coastal vulnerability across the Pacific dominated by El Niño/Southern Oscillation
Barnard, P. L., Short, A. D., Harley, M. D., Splinter, K. D., Vitousek, S., Turner, I. L., Jonathan Allan, Masayuki Banno, Karin R. Bryan, André Doria, Jeff E. Hansen, Shigeru Kato, Yoshiaki Kuriyama, Evan Randall-Goodwin, Peter Ruggiero, Ian J. Walker & Heathfield, D. K. (2015). Coastal vulnerability across the Pacific dominated by El Niño/Southern Oscillation. Nature Geosci, 8(10), 801–807. Retrieved from http://dx.doi.org/10.1038/ngeo2539
A new study published in Nature Geoscience, examined the understudied dynamic forces that act on coastal waters during storms. These understudied physical forces include wave-driven processes, storm surges, and seasonal water level anomalies, all factors that can greatly increase coastal water levels during extreme events. Barnard et al. (2015) looked at 33 years of data (1979-2012) measuring wave climate, local water levels, and coastal change, for 48 beaches throughout the Pacific Ocean Basin. The authors found that El Niño was the dominant factor influencing coastal erosion, and that conditions of Northeast Pacific beaches often opposed conditions of beaches in the western and southern Pacific Ocean. From these results, the study concluded that opposite sides of the Pacific Ocean will be alternately exposed to coastal erosion and flooding, and that these processes will become more extreme as El Niño/La Niña oscillations are projected to increase in frequency.
Effects of climate change on coastal upwelling ecosystems
Bakun A, Black BA, Bograd SJ, Garcia-Reyes M, Miller AJ, Rykaczewski RR, Sydeman WJ (2015) Anticipated effects of climate change on coastal upwelling ecosystems. Current Climate Change Reports 1,2: 85-93. doi: 10.1007/s40641-015-0008-4
A new edition of Current Climate Change Reports focuses on the ecological impacts of climate change, with a section on coastal upwelling ecosystems. Coastal upwelling zones occur in the Pacific and Atlantic Oceans along the edges of the eastern boundary currents. They are one of the most productive marine ecosystems in the world. The zones occur as winds along the shore interact with the rotation of the earth to move surface waters offshore, which results in upwelling of nutrients from deeper waters to surface waters. Consequently, there is a large population of zooplankton and small pelagic fish. The fish are often an important trophic control for large populations of seabirds and marine mammals. This study finds that productivity in these zones is under threat due to climate change impacts. Intensification of upwelling is expected, which might lead to hypoxic events and less food particles for fish larvae. Ocean acidity will rise, which will affect organisms that have carbonate structures. Large-scale impacts on pelagic fish seem unlikely, but shifts in the composition of species are expected.
Analysis of the quahog clam reveals how the oceans affected the climate over the past 1,000 years
D. J. Reynolds, J. D. Scourse, P. R. Halloran, A. J. Nederbragt, A. D. Wanamaker, P. G. Butler, C. A. Richardson, J. Heinemeier, J. Eiríksson, K. L. Knudsen, I. R. Hall. Annually resolved North Atlantic marine climate over the last millennium. Nature Communications, 2016; 7: 13502 DOI: 10.1038/ncomms13502
A collaborative team of researchers have used growth rings in the shells of the longest-living animal, the quahog clam, to obtain an absolutely dated marine 18O archive for the past 1,000 years. Obtained from the North Icelandic shelf, the record lengthens our historical knowledge of the planet’s climate system by nearly a magnitude of ten. The record shows that before the industrial period (1000-1800), the North Atlantic ocean was a dominant driver in modulating the planet’s climate in response to solar and volcanic forcing. However, this observed relationship ceased during the industrial period and the onset of human-induced climate change. During the industrial period (1800-2000), the North Atlantic exhibited synchronized changes with the atmosphere, suggesting that anthropogenic climate change may be masking the natural dynamics of the planet’s climatic system.
Pacific Ocean becomes a caldron
Schwartz, John. (2015). The Pacific Ocean Becomes a Cauldron. The New York Times. Retrieved from http://www.nytimes.com/2015/11/03/science/global-warming-pacific-ocean-e...
John Schwartz of the New York Times summarizes all the factors playing into why the Pacific Ocean has exhibited such anomalous behavior of late. Specifically recalling the extreme strength of Hurricane Patricia off the coast of Mexico, and the subsequent desire to peg it as the consequence of a specific event, Schwartz lists the myriad of climatic processes currently acting on the Pacific Ocean and therefore the difficulty in blaming the hurricane on a single cause. From the formation of a strong El Nino system along the Equator, to the “Blob” of warm water sitting off the North American coast, to the warming shift of the Pacific Decadal Oscillation, it is possible that the Pacific Ocean is experiencing extreme conditions formed through the combination of these individual processes. Schwartz interviewed Washington State Climatologist Nick Bond who concludes that the confluence of problems can serve as a “wake-up call,” and a harbinger of future conditions under climate change.
Short-lived greenhouse gases cause centuries of sea-level rise
Kirsten Zickfeld, Susan Solomon, and Daniel M. Gilford. Centuries of thermal sea-level rise due to anthropogenic emissions of short-lived greenhouse gases. PNAS, January 2017 DOI: 10.1073/pnas.1612066114
Researchers at Massachusetts Institute of Technology and Simon Fraser University recently published their findings on the effect of short-lived greenhouse gases on sea-level rise. Using an Earth’s Systems Model (EMIC), the study quantified global temperature and sea-level rise in response to various greenhouse gas emission scenarios. Estimates of the effects of carbon dioxide (a long-lived greenhouse gas) were in line with previous studies, however the short-lived greenhouse gases, such as methane, exhibited a much longer impact on sea-level rise than formerly expected. They found that thermal expansion continues well after methane has cleared the atmosphere, and that this lag time only worsens the longer humans wait to reduce methane emissions. In order to test this, the study looked at the impacts of chlorofluorocarbons (CFCs) in the atmosphere and simulated their lasting effects had we not reduced emissions. They found that sea-level rise would be 6 inches higher by 2050 had CFCs not been reduced.
Ocean's oxygen running low
Long, M. C., C. Deutsch, and T. Ito (2016), Finding forced trends in oceanic oxygen, Global Biogeochem. Cycles,30, 381–397, doi:10.1002/2015GB005310.
Unviersity of Washington oceanographer Curtis Deutsch and colleagues have recently published a new study examining the distinction between naturally varying and climate-induced declines in dissolved oxygen levels of the world’s oceans. Using a large ensemble of a single Earth System model, the authors developed a global map of changing oxygen levels and found that it was possible to discern climate-driven changes from other sources. They found that for each degree of warming, oxygen concentration declined by 2 percent. Warmer waters lead to a more stratified ocean which consequently cuts off oxygen supply to habitable parts of the marine ecosystem. Furthermore, increased ocean temperatures cause the metabolic rate of marine species to increase, thus requiring increased oxygen consumption. As Curtis Deutsch stated, this means climate change is squeezing marine species on both sides. That authors stress the importance of including research on dissolved oxygen when discussing the effects of climate change on the ocean. Along with warming and acidification, a decline in oxygen will have extreme impacts on the marine ecosystem.
Solutions for ecosystem-level protection of ocean systems under climate change
Queirós, A. M., Huebert, K. B., Keyl, F., Fernandes, J. A., Stolte, W., Maar, M., Kay, S., Jones, M. C., Hamon, K. G., Hendriksen, G., Vermard, Y., Marchal, P., Teal, L. R., Somerfield, P. J., Austen, M. C., Barange, M., Sell, A. F., Allen, I. and Peck, M. A. 2016. Solutions for ecosystem-level protection of ocean systems under climate change. Glob Change Biol, 22: 3927–3936. doi:10.1111/gcb.13423
An international team of scientists examined the ecosystem-level protection of ocean habitats under current regional conservation plans. Using a spatial meta-analysis of climate impact models, the team co-mapped ecosystem vulnerability and human activities (i.e. the placement of renewable energy developments and the distribution of marine protected areas). The team identified current unprotected ocean habitats that will likely serve as climate refuges for vulnerable ocean ecosystems under climate change and ocean acidification impacts. They found that current regional conservation plans disregard the redistribution of marine species to new, suitable and productive habitats (refuges). Such refuge areas are currently unprotected and open to possible anthropogenic threat via commercial extraction and other uses.
Carbon cycling in Pacific coastal wetlands
Janousek, C.N., Buffington, K.J., Guntenspergen, G.R. et al. 2017. Ecosystems doi:10.1007/s10021-017-0111-6
A group of scientists led by Karen Thorne of the USGS Western Ecological Research Center and funded by the Northwest Climate Science Center recently published a paper from their study of coastal wetlands in the journal Ecosystems. The paper describes the results of their experiments across a latitudinal and climate gradient of tidal marshes in the Northeast Pacific to evaluate how climate change may affect the ability of coastal wetlands to cycle and sequester carbon. Results could help land managers build climate resilience into coastal wetlands.
Naturally Acidic Water of Puget Sound Surround UW’s Friday Harbor Labs
Murray, J. W., Roberts, E., Howard, E., O'Donnell, M., Bantam, C., Carrington, E., Foy, M., Paul, B. and Fay, A. (2015), An inland sea high nitrate-low chlorophyll (HNLC) region with naturally high pCO2. Limnology and Oceanography. doi: http://dx.doi.org/ 10.1002/lno.10062
A paper published last month in Limnology and Oceanography tracks about two years of weekly pH data in Puget Sound, collected since the UW established a facility there to study the effects of ocean acidification. Researchers found typical values of dissolved carbon dioxide, or CO2, in Puget Sound are more than 650 parts per million, higher than even the 400 parts per million threshold that Earth’s atmosphere crossed last year for the first time in modern humans’ existence. In other words, Puget Sound’s water is already higher in the gas than our CO2-choked atmosphere.
Coastal marshes more resilient to sea-level rise than previously believed
Ratliff, K.M., Braswell, A.E. and Marani, M., 2015. Spatial response of coastal marshes to increased atmospheric CO2. Proceedings of the National Academy of Sciences, 112(51), pp.15580-15584.
Accelerating rates of sea-level rise linked to climate change pose a major threat to coastal marshes and the vital carbon capturing they perform. But a new Duke University study finds marshes may be more resilient than previously believed. Elevated levels of atmospheric CO2 boost plant biomass production, allowing marshes to trap more sediment and generate more organic soil. This may elevate the threshold rate of relative sea-level rise at which marsh drowning is initiated by up to 60 percent. This natural process may also contribute to a stabilizing feedback in the climate system as increased biomass production and organic deposition in marshes lead to increased carbon dioxide sequestration. However, the ultimate health of coastal marshes will be determined by inorganic sedimentation that is at risk due to damming and agricultural practices that continue to hurt the ability of marshes to build themselves up and protect against sea level rise.
NOAA: ‘Nuisance flooding’ an increasing problem as coastal sea levels rise.
Study looks at more than 60 years of coastal water level and local elevation data changes. Eight of the top 10 U.S. cities that have seen an increase in so-called “nuisance flooding”--which causes such public inconveniences as frequent road closures, overwhelmed storm drains and compromised infrastructure--are on the East Coast, according to a new NOAA technical report. This nuisance flooding, caused by rising sea levels, has increased on all three U.S. coasts, between 300 and 925 percent since the 1960s. The report, Sea Level Rise and Nuisance Flood Frequency Changes around the United States, also finds Annapolis and Baltimore, Maryland, lead the list with an increase in number of flood days of more than 920 percent since 1960. Port Isabel, Texas, along the Gulf coast, showed an increase of 547 percent, and nuisance flood days in San Francisco, California increased 364 percent.
Northern Rock Sole Larvae Appear Resilient to Some Effects of Ocean Acidification
Hurst, T. P., Laurel, B. J., Mathis, J. T., and Tobosa, L. R. Effects of elevated CO2 levels on eggs and larvae of a North Pacific flatfish. ICES Journal of Marine Science, doi: http://dx.doi.org/10.1093/icesjms/fsv050.
A study done by NOAA Fisheries in collaboration with NOAA’s Pacific Marine Environmental Lab and Oregon State University’s Hatfield Marine Science Center was published in the ICES Journal of Marine Science testing how newly hatched northern rock sole growth and development could respond to a more acidic ocean, an ocean with higher levels of carbon dioxide (CO2), and lower pH. Reduced pH levels predicted for ocean acidification did not hamper growth and development of young northern rock sole. However, the authors caution that there are other potential impacts to northern rock sole that have yet to be examined as ocean acidification may alter the abundance of the tiny crustaceans that small rock sole feed upon. In addition, elevated CO2 levels have been shown to disrupt feeding and migration behaviors in other fish species
Study Published on Storage and Release of Organic Carbon from Glaciers and Ice Sheets
Hood, E., Battin, T.J., Fellman, J., O'Neel, S., Spencer, R.G.M. 2015. Storage and release of organic carbon from glaciers and ice sheets. Nature Geosceince, doi: http://dx.doi.org/ 10.1038/ngeo2331
The impact from melting glaciers due to climate change is more complex than just causing changes to global sea-levels. Melting glaciers will impact the flow of organic carbon to oceans around the world. This study provides a global-scale estimate for the storage and release of organic carbon from melting glaciers. This research is crucial to better understand the role glaciers play in the global carbon cycle, especially as climate warming continues to reduce glacier ice stores and release ice-locked organic carbon into downstream freshwater and marine ecosystems. Glaciers represent a substantial reservoir of organic carbon and as glaciers are lost worldwide along with the corresponding release of carbon, high-latitude marine ecosystems will be affected.
Future fisheries can expect $10 billion revenue loss due to climate change
Vicky W. Y. Lam, William W. L. Cheung, Gabriel Reygondeau, U. Rashid Sumaila. Projected change in global fisheries revenues under climate change. Scientific Reports, 2016; 6: 32607 DOI: 10.1038/srep32607
Scientists from the University of British Columbia recently published a study examining how climate change will alter fisheries revenues of maritime countries. Vicky Lam and colleagues used climate-living marine resource simulation models and found that global fisheries revenues could drop by 35% more than the projected decrease in catches by the 2050s under high carbon emission scenarios. On a regional scale, changes in revenue varied greatly, with the largest negative impact likely to occur in the equatorial Pacific. The region of the Pacific Ocean near the Northwest U.S. was projected to experience minimally negative impacts to fisheries revenue (see Figure 2 of the study).
Ocean acidification is being exacerbated by local factors
Chan, F., Boehm, A.B., Barth, J.A., Chornesky, E.A., Dickson, A.G., Feely, R.A., Hales, B., Hill, T.M., Hofmann, G., Ianson, D., Klinger, T., Largier, J., Newton, J., Pedersen, T.F., Somero, G.N., Sutula, M., Wakefield, W.W., Waldbusser, G.G., Weisberg, S.B., and Whiteman, E.A. The West Coast Ocean Acidification and Hypoxia Science Panel: Major Findings, Recommendations, and Actions. California Ocean Science Trust, Oakland, California, USA. April 2016.
A new report released by the California Ocean Science Trust and written by a panel of 20 scientists from California, Oregon and Washington, synthesized our current understanding of how the Puget Sound and other coastal waters along western North America are being impacted by ocean acidification. The report examined local reasons for why the west coast is experiencing exacerbated acidification compared to other oceanic regions. A major factor includes the massive amounts of nitrogen and carbon that are dumped into estuaries (particularly the Puget Sound) by municipal wastewater treatment plants and agricultural runoff, causing extreme plankton blooms that then lead to hypoxia and significant increases in CO2 production. Another localized factor is the characteristic of water being upwelled on the western coast. Water being upwelled around the Puget Sound contain naturally high levels of CO2 and lower pH. These local factors combined with the global increase in oceanic CO2 concentrations has lead the West Coast of North America to be one of the regions of the world most severely impacted by changes to ocean chemistry. The report concluded on a hopeful note, with a reminder that the local processes affecting ocean acidification are currently dominating over oceanic processes. Therefore, regions like the Puget Sound can take meaningful local action to mitigate these changes.
Climate Change Effects Along a Latitudinal Gradient in the Pacific Northwest
The USGS National Climate Change and Wildlife Science Center has completed a three-year long study investigating the effects of sea-level rise on nine tidal marshes in Washington and Oregon. With the goal of providing scientific data to support future coastal planning and conservation, the investigators compiled physical and biological data to assess and model how sea level rise may alter these ecosystems in the future. The project concludes that multiple factors, including initial elevation, marsh productivity, sediment availability, and rates of sea-level rise, affected marsh persistence. Under a low sea-level rise scenario, all marshes remained vegetated with little change in the present configuration of marsh plant communities or gradually increased proportions of mid, high, or transition marsh vegetation zones. However at most sites, mid sea level rise projections led to loss of middle and high marsh and gain of low marsh habitat. Under a high sea level rise scenario, marshes at most sites eventually converted to intertidal mudflats. Two sites (Grays Harbor, and Willapa) appeared to have the most resilience to a high sea-level rise rate, persisting as low marsh until at least 2110. Their main model finding is that most tidal marsh study sites have resiliency to sea-level rise over the next 50-70 years, but that sea-level rise will eventually outpace marsh accretion and drown most high and mid marsh habitats by 2110.
Analysis of Otoliths Suggest that Growth Slows With Sea Level Rise for a Deepwater Predatory Fish
Otoliths are little structures that most fish have in their skulls. Because layers of mineral are added to otoliths throughout a fish’s life, they can act as a reliable record of growth patterns — periods of feast and famine — just like tree rings. Now, scientists are using these structures to show how fish size may decrease as a result of a changing ocean.
New Study on Sea Level Rise Points to Much Higher Projections Than Before
Hansen, J., Sato, M., Hearty, P., Ruedy, R., Kelley, M., Masson-Delmotte, V., Russell, G., Tselioudis, G., Cao, J., Velicogna, I., Kandiano, E., von Schuckmann, K., Kharecha, P., Legrande, A.N., Bauer, M., Lo, K.-W. 2015. Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 degrees C global warming is highly dangerous. Atmos. Chem. Phys. Discuss., 15, 20059-20179.
A new study by acclaimed NASA climate scientist James Hansen and colleagues claims that sea level rise will occur much more rapidly than forecast by the Intergovernmental Panel on Climate Change. Hansen and colleagues project a sea level rise of 5 – 9 meters in 50, 100 or 200 years if fossil fuel emissions continue on a ‘business-as-usual’ course (meaning that emissions as they are now would continue in the future). The rate of sea level rise would be accelerated by parts of the Antarctica and Greenland ice sheets melting, and this melting would bring about a number of climate change ‘feedbacks’, which would in turn increase the rate of melting. However, this study has generated considerable controversy and criticism. Other prominent climate scientists, such as Kevin Trenberth of the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, have strongly criticized the study, arguing that Hansen and colleagues made too many assumptions and extrapolations for the study to be taken seriously. However, the IPCC has been criticized in the past for making overly conservative projections, including for sea level rise. Greg Holland, also at NCAR, argues that the actual amount of sea level rise that will occur is probably somewhere between the amount projected by this study and the IPCC.
Marine carbon sinking rates confirm importance of cold water oceans
Weber, T., Cram, J.A., Leunga, S.W., DeVries, T., & Deutsch, C. 2016. Deep ocean nutrients imply large latitudinal variation in particle transfer efficiency. Proc Natl Acad Sci USA, 113 (31): 8606-8611. doi: 10.1073/pnas.1604414113.
A new study from the University of Washington examined the sinking rates of marine carbon in various regions of the world’s oceans. Using a data-constrained ocean circulation model as well as estimates of organic matter export from the sea surface, the authors were able to calculate the “transfer efficiency” of organic matter to the deep ocean. The study found that higher latitudes were the most efficient marine carbon sinks while subtropical gyres were the least efficient. These findings emphasize the significance of high-latitude, cold water oceans for marine carbon sequestration and predict a reduction in this natural carbon storage as temperatures warm.
NOAA Releases Climate Science Strategy for Fisheries
The National Marine Fisheries Service (NMFS), housed by NOAA, has released a five-year climate science strategy (still in draft form) highlighting challenges faced by fishery managers amid warming oceans, rising sea levels, and ocean acidification. The draft strategy outlines seven steps that will be carried out over the next five years. The steps range from “robust strategies” for managing fisheries under a changing climate to identifying “future states” of marine ecosystems. This strategy comes out one month after the NMFS, in collaboration with Rutgers University, released OceanAdapt, a website allowing fishermen and policymakers to track shifting fish populations.
Doubling of coastal flooding frequency within decades due to sea-level rise
Vitousek, S.; P.L. Barnard; C.H. Fletcher; N. Frazer; L. Erikson & C.D. Storlazzi. 2107. Doubling of coastal flooding frequency within decades due to sea-level rise. Scientific Reports 7, Article number: 1399 doi:10.1038/s41598-017-01362-7 Published online: 18 May 2017
According to the International Panel on Climate Change, sea level rise is projected to increase, which will also increase the frequency of coastal flooding. A team of researchers used extreme value theory to combine sea-level projections with wave, tide and storm surge models to estimate increases in coastal flooding on a global scale. They found that places that had little variability in water level (mainly in the tropics) will likely have the largest increases in flooding frequency. The 10 to 20 cm of sea-level rise projected by 2050 will more than double the frequency of extreme water-level events in the tropics, hindering the developing economies of equatorial coastal cities and the livability of low-lying Pacific island nations.
West Coast study emphasizes challenges faced by marine organisms exposed to global change
George N. Somero, Jody M. Beers, Francis Chan, Tessa M. Hill, Terrie Klinger, Steven Y. Litvin. What Changes in the Carbonate System, Oxygen, and Temperature Portend for the Northeastern Pacific Ocean: A Physiological Perspective. BioScience, 2016; 66 (1): 14 DOI:10.1093/biosci/biv162
Physiological changes that are common to many marine taxa can be a useful measurement when applying regional research to global change. A new study published in BioScience examined certain physiological changes to marine taxa off the West Coast of the U.S. in order to develop a global model for how other areas of the ocean could respond to future warming, acidification, and low dissolved oxygen concentrations (hypoxia). The West Coast displayed all three of these ocean stressors, making it a valuable study area for understanding how a multiple-stressor ocean will impact its ecosystem. The team of scientists synthesized dozens of studies analyzing various physiological responses to these three ocean stressors and found that physiological changes in marine organisms can lead to changes in animal behavior, biogeography, and ecosystem structure. The study concluded that these ocean stressors (acidification, hypoxia, and warming) will most likely co-occur in marine environments, and therefore understanding their effects in concert with one another is critical.
Ocean acidification threatening shellfish hatcheries
Waldbusser, G.G., Hales, B., Langdon, C.J., Haley, B.A., Schrader, P., Brunner, E.L., Gray, M.W., Miller, C.A., and Gimenez, I. 2014. Saturation-state sensitivity of marine bivalve larvae to ocean acidification. Nature Climate Change.doi: http://dx.doi.org/10.1038/nclimate2479
A recent study published in Nature Climate Change has found that the Pacific oyster and Mediterranean mussel larvae are sensitive to saturation state, and not carbon dioxide partial pressure or pH. Saturation state is a measure of how corrosive seawater is to calcium carbonate shells of calcifying organisms. Successful larval development and growth during shell formation is heavily dependent on seawater saturation state. While pH levels affect other physiological processes, the saturation state threshold will be crossed decades earlier than pH thresholds, due to the nonlinear responses of saturation state as atmospheric CO2 concentrations are increased. This study adds to the body of evidence suggesting that moderate ocean acidification impacts almost caused the complete collapse of the PNW oyster industry.
Artificial fertilization of the ocean may render positive and negative effects
Grandey BS and Wang C. Enhanced marine sulphur emissions offset global warming and impact rainfall. Scientific Reports 5: 13055. doi: 10.1038/srep13055
Artificial fertilization of the ocean is a possible geoengineering method for removing carbon dioxide from the atmosphere. Artificial fertilization may result in an increase in emissions of dimethyl sulphide (DMS), which is the largest source of sulphate aerosols over remote ocean regions. Increasing sulphate aerosols can cause direct and indirect cooling effects on climate. This study used two emissions scenarios, an RCP 4.5 control and an RCP 4.5 test case in which DMS emissions were increased significantly over oceans. They found that the direct and indirect cooling effects associated with increasing aerosol emission from the oceans resulted in a significant offset of warming around the world. However, an increase in aerosols may have other harmful effects. Aerosols also become part of rainfall, and could be harmful for human health. Consequently, the authors conclude that altering marine phytoplankton activity via artificial fertilization might lead to a combination of positive and negative effects on climate and human health.
For Corals Adapting to Climate Change, It’s Survival of the Fattest—and Most Flexible
Grottoli, A. G., Warner, M. E., Levas, S. J., Aschaffenburg, M. D., Schoepf, V., McGinley, M., Baumann, J. and Matsui, Y. (2014), The cumulative impact of annual coral bleaching can turn some coral species winners into losers. Global Change Biology. doi: 10.1111/gcb.12658
The future health of the world’s coral reefs and the animals that depend on them relies in part on the ability of one tiny symbiotic sea creature to get fat—and to be flexible about the type of algae it cooperates with. In the first study of its kind, scientists at The Ohio State University discovered that corals—tiny reef-forming animals that live symbiotically with algae—are better able to recover from yearly bouts of heat stress, called “bleaching,” when they keep large energy reserves—mostly as fat—socked away in their cells.
Abrupt tipping points
Drijfhout, S., Bathiany, S., Beaulieu, C., Brovkin, V., Claussen, M., Huntingford, C., & Swingedouw, D. (2015). Catalogue of abrupt shifts in Intergovernmental Panel on Climate Change climate models. Proceedings of the National Academy of Sciences, 201511451.
One of the most concerning consequences of human-induced increases in atmospheric greenhouse gas concentrations is the potential for rapid regional transitions in the climate system. Yet, despite much public awareness of how “tipping points” may be crossed, little information is available as to exactly what may be expected in the coming centuries. In this study, a group of scientists assessed all Earth System Models underpinning the recent 5th Intergovernmental Panel on Climate Change report and systematically searched for evidence of abrupt changes. The authors found abrupt changes in sea ice, oceanic flows, land ice, and terrestrial ecosystem response, although with little consistency among the models. A particularly large number of abrupt changes was projected for warming levels below 2° C, a warming level commonly acknowledged as safe. The authors discuss mechanisms and include methods to objectively classify abrupt climate change.
Climate change and marine vertebrates
Sydeman, W.J., E. Poloczanska, T.E. Reed, and S.A. Thompson. (2015). Climate change and marine vertebrates. Science 13 (350, no. 6262): 772-777, doi: 10.1126/science.aac9874
A new study published in the special Oceans and Climate section of Science examined the direct and indirect effects of anthropogenic climate change on marine vertebrates. The study reviewed marine fish, mammal, turtle, and seabird responses to climate change and discussed their potential for adaptation. The authors found that every observed ocean demonstrated both direct and indirect responses, and identified mechanisms of change to be direct physiological responses and climate-mediated predator-prey interactions. The endothermic organisms that the study observed (i.e. seabirds and mammals) responded indirectly to climate change, while the ectothermic fish were observed to respond immediately to small changes in temperature and oxygen concentration. The study emphasized that, although indirect responses are less immediate compared to those that are direct, they are powerful and difficult to reverse. The study concluded by stressing the need to integrate climate, oceanographic, ecosystem, and population models that incorporate evolutionary processes in order to prioritize climate-related conservation needs for marine vertebrates.
The normal fire environment—Modeling environmental suitability for large forest wildfires using past, present, and future climate normals
Davis, R, Yang, Z, Yost, A, Belongie, C & Cohen, W. 2017. The normal fire environment—Modeling environmental suitability for large forest wildfires using past, present, and future climate normals. Forest Ecology & Management (390) 173-186. 10.1016/j.foreco.2017.01.027
Researchers modeled the normal fire environment for occurrence of large forest wildfires for the Pacific Northwest Region of the United States. Large forest wildfire occurrence data from the recent climate normal period (1971–2000) was used as the response variable and fire season precipitation, maximum temperature, slope, and elevation were used as predictor variables. Researchers used downscaled climate projections for two greenhouse gas concentration scenarios and over 30 climate models to project changes in environmental suitability for large forest fires over the 21st century. Results indicated an increasing proportion of forested area with fire environments more suitable for the occurrence of large wildfires over the next century for all ecoregions, but less pronounced for the Coast Range and Puget Lowlands. The largest increases occurred on federal lands. By the end of the century, the models predicted shorter fire rotation periods, with cooler/moister forests experiencing larger magnitudes of change than warmer/drier forests. Modeling products, including a set of time series maps, can provide forest resource managers, fire protection agencies, and policy-makers empirical estimates of how much and where climate change might affect the geographic distribution of large wildfires and fire rotations.
Climate-induced variations in global wildfire danger from 1979 to 2013
Jolly, W. M., Cochrane, M. A., Freeborn, P. H., Holden, Z. A., Brown, T. J., Williamson, G. J., & Bowman, D. M. J. S. (2015). Climate-induced variations in global wildfire danger from 1979 to 2013. Nat Commun, 6. doi.org/10.1038/ncomms8537
A new study published inNature Communications examined global changes in wildfire frequency and season length. The authors used three daily global climate datasets to measure fire weather season length and temporal and spatial distribution from 1979 to 2013. The study found that the duration of fire weather seasons has increased 18% across one quarter of the Earth's vegetated surface. The results also exhibited a doubling of global burnable area affected by long fire weather seasons. Specific to the United States, the study found that over the last several decades, the U.S. has witnessed a marked increase in large wildfire frequency and duration with the greatest increases observed in the temperate coniferous forests of the Northern Rocky Mountains. The study concludes that these global changes in wildfire patterns could have significant impacts on global ecosystems, societies, economies, and climate.
U.S. federal fire and forest policy: emphasizing resilience in dry forests
Stephens, S. L., Collins, B. M., Biber, E. and Fulé, P. Z. (2016), U.S. federal fire and forest policy: emphasizing resilience in dry forests. Ecosphere, 7: n/a, e01584. doi:10.1002/ecs2.1584
A new report released in the journal Ecosphere proposes a revision to federal forest fire policy. Authored by researchers from the University of California, Berkeley and Northern Arizona University, the report makes recommendations geared toward improving the management of forest restoration and wildland fire. The proposal includes giving forest restoration equal priority to other fields of land management, rewriting federal planning documents to disincentivize fire suppression and incentivize managed wildland fire, new federal partnerships with States and local governments, and efforts to manage for long-term forest resilience in addition to short-term fire suppression.
Are insect outbreaks helping reduce forest fires?
Meigs, G.W., Zald, H.S.J., Campbell, J.L., Keeton, W.S., Kennedy R.E. 2016. Do insect outbreaks reduce the severity of subsequent forest fires? Environmental Research Letters: 11, 4.
Researchers from the University of Vermont and Oregon State University examined the interaction between insect outbreaks and fire severity. Published in Environmental Research Letters, the authors used spatial models and statistical analyses to map 81 fires as well as insect outbreaks over a 25-year period in Oregon and Washington state. Specifically, the study looked at mountain pine beetle and western spruce budworm outbreaks. Findings from this study suggest that the presence of both insects generally reduced wildfire severity by decreasing the abundance of live vegetation susceptible to wildfire at multiple time lags. Because this is contrary to common assumption, the authors recommended a precautionary approach to forest management policies.
Learning to Coexist with Wildfire
Moritz, M.A., E. Batllori, R.A. Bradstock, A. M. Gill, J. Handmer, P.F. Hessburg, J. Leonard, S. McCaffrey, D.C. Odion, T. Schoennagel, & A. D. Syphard. 2014. Learning to coexist with wildfire. Nature: 515, 58-66. doi:10.1038/nature13946 http://www.nature.com/nature/journal/v515/n7525/full/nature13946.html
Authors of a recent paper in Nature argue for shifting from forest wildland policies of fighting fire to coexisting with fire as a natural process. They examined natural and social science data from three continents and concluded that government-sponsored firefighting encourages development on inherently hazardous landscapes, amplifying human losses over time. The authors argue that wildfires are a natural part of many ecosystems, serving important functions such as stimulating plant regeneration, promoting biodiversity and sustaining nutrient cycling. The authors recommend treating wildfire fire like other natural disasters including earthquakes and prioritizing location-specific approaches to improve development and safety in fire-prone areas.
National cohesive wildland fire management strategy Western Region 2016 accomplishment report
It is the mission of the National Cohesive Wildland Fire Management Strategy to promote and facilitate resilient landscapes, fire adapted communities, and a safe, effective, risk-based wildland fire response across the western landscape using a network approach. Its 2016 Accomplishment Report highlights progress in the following categories: communications, existing systems and networks, relationship building, engagement for fire adapted communities, implementation, large landscape collaboration, networking the cohesive strategy, and the return on investment.
Homeowners and wildfire risk: climate change beliefs and hazard mitigation behaviors
Brenkert-Smith, H., Meldrum, J. R., & Champ, P. A. 2015. Climate change beliefs and hazard mitigation behaviors: homeowners and wildfire risk. Environmental Hazards, 14(4), 341-360. DOI: 10.1080/17477891.2015.1080656
University of Colorado scientists surveyed people experiencing exacerbated hazards due to climate change and assessed their understanding and response to climate-related changes to these local hazards. This new study examined the relationships among climate change beliefs, environmental beliefs, and hazard mitigation actions in the context of wildfire, a natural hazard projected to be intensified by climate change. The study found that survey respondents were situated across a continuum between being ‘believers’ and ‘deniers’ that is multidimensional. Placement on this believer–denier spectrum was related to general environmental attitudes. However, no relationship was found between climate change beliefs and wildfire risk-reduction actions in general. In contrast, the study found a statistically significant positive relationship between level of wildfire risk mitigation and being a climate denier. Further, certain pro-environmental attitudes were found to have a statistically significant negative association with the level of wildfire risk mitigation.
A spatial stochastic programming model for timber and core area management under risk of fires
Wei, Yu; Bevers, Michael; Nguyen, Dung; Belval, Erin. 2014. A spatial stochastic programming model for timber and core area management under risk of fires. Forest Science. 60(1): 85-96. Online: http://www.treesearch.fs.fed.us/pubs/46563.
This study analyzed the effect of random stand-replacing fire on the implications of various harvest and mature forest core area decisions for forests. Results indicate that integrating the occurrence of stand-replacing fire into forest harvest scheduling models can improve the quality of long-term spatially explicit forest plans.
Big Fires More Frequent Across Western Region
Dennison, P. E., Brewer, S.C, Arnold, J.D., & Moritz, M.A. (2014) Large wildfire trends in the western United States, 1984–2011, Geophys. Res. Lett., 41, 2928–2933, doi:10.1002/2014GL059576 and Littell, J.S., McKenzie, D., Peterson, D.L. & Westerling, A.L. (2009) Climate and wildfire area burned in western U.S. ecoprovinces, 1916–2003. Ecological Applications, 19, 1003–1021. doi: 10.1890/07-1183.1
Fires are among the most destructive climate-related natural hazards in the western United States. A new analysis of satellite data shows that large fires have become more frequent over the past 30 years. Using high-resolution satellite data, Philip Dennison and colleagues tallied up the number of fires larger than 1,000 acres— almost 7,000 fires in all— and aggregated them over nine eco-regions. The scientists then calculated linear trends from 1984 to 2011.
Total burned area trended upward in all nine eco-regions, and the total area burned across the West increased at an average rate of 355 square kilometers per year. The number of large fires trended upward in seven of the nine, including all three of the Northwest eco-regions (the Cascade/Klamath/Sierra mountains, the Snake Plain/Columbia Plateau, and the northern Rockies). However, in the Cascades eco-region, the very largest fires (90th percentile) are decreasing at 3 square kilometers per year. Climatologists are hesitant to identify a trend for a period as short as three decades. But earlier analysis by Jeremy Littell and colleagues demonstrated that between 1916 and 2003— nearly a century — wildfire area burned in the western United States increased and, importantly, climate was the primary driver, “despite the possible influence of fire suppression, exclusion, and fuel treatment.” The relationships between climate and area burned, however, are different in each eco-region, according to the researchers, owing, for example, to the relative importance of early spring snowmelt or summer heat in drying the forests enough to burn.
Climate change has doubled Western U.S. forest fires
John T. Abatzoglou, A. Park Williams. 2016. Impact of anthropogenic climate change on wildfire across western US forests. Proceedings of the National Academy of Sciences, 201607171 DOI: 10.1073/pnas.1607171113
University of Idaho climate scientist John Abatzoglou and bioclimatologist Park Williams from Columbia University's Lamont-Doherty Earth Observatory recently published a report examining the impact of climate change on the extent of land threatened by forest fires in the western United States. The authors used climate projection models to evaluate the contributions of human-induced climate change on observed increases in fuel aridity metrics and forest fire area, and found that area affected by forest fires has doubled over the last 30 years. The study concluded that further anthropogenic warming and increases in vapor pressure deficit will continue to exacerbate western U.S. fire activity.
A Year Round Fire Season?
There was a time when fire season for Western states meant only certain months out of the year. Not so long ago the U.S. Forest Service considered it primarily a summer problem with a few regions breaking the trend in early spring and late fall. But climate change, according to most wildland fire experts, has turned fire season into a year-round issue. What used to slow down fire season was winter—a long and cold time of year with lots of snow that killed off many invasive or destructive pests and filled rivers and reservoirs with ample water to supply the needs of millions living in the West. Now winter is shorter and has far less snow accumulation in many areas.
WA Experiences Worst Fire Year On Record
Washington has been experiencing its worse fire year on record, and the year is not yet completed. Approximately 732,608 acres have burned, and the Okanogan Complex fire has been the largest wildfire that the state has every seen. Prior to 2015, 2014 was considered to be the worst year yet. Washington Department of Natural Resources director Peter Goldmark stated “It’s been a wildfire season of enormous proportion and consequence and impact on people.” Goldmark further stated that the DNR’s staff and resources are stretched thin, despite the overwhelming number of volunteers they have had.
Predicting Large Wildfires Across the West by Modeling Seasonal Variation in Soil Water
Waring, R.H. and Coops, N.C. 2016. Predicting large wildfires across western North America by modeling seasonal variation in soil water balance. Climatic Change, 135 (2).
This paper presents an approach to help identify forested areas where management efforts to reduce fire hazards might prove most beneficial. The authors constructed a decision tree model to establish general relationships among evaporation, transpiration and tree flammability. To test their decision tree model they used NASA imaging data to map large fires between 2000-2009 and analyzed seasonal variability in soil water for 2001, 2004 and 2007. They found that, for the three years selected, their decision model tree predicted where forest fires more than a kilometer occurred and did not occur with an average accuracy of 69%. The decision tree identified four seasonal combinations, most of which included exhaustion of available soil water, during the summer as critical- two combinations involving conditions the previous spring or fall accounted for 86% of the predicted fires.
Adapting fuel treatments in a changing climate - Prescribed fire, mechanical treatments, wildfire, and restoration
The Available Science Assessment Project (ASAP) leads, EcoAdapt and Oregon State University’s Institute for Natural Resources, have published a summary of a workshop they hosted last April during the International Association of Wildland Fire’s 5th Fire Behavior and Fuels Conference, in cooperation with the Northwest Fire Science Consortium and the Northern Rockies Fire Science Network. Thirty-six managers and scientists from 30 organizations attended the workshop, representing a range of federal and state agencies, tribal governments, non-profits, universities, and other research organizations. The workshop explored on-the-ground climate adaptation actions that might be used for fire and fuels management under future climate conditions. Specifically, workshop participants were asked to identify the likely impacts of climate change and what they saw as barriers and potential opportunities for the use of four management actions: prescribed fire; mechanical fuel treatment; managed wildfire; and post-fire restoration (seeding/planting). Their responses are summarized in this short report. The ASAP project was funded in part by the Northwest Climate Science Center.
Will The West Ever Be Able To Live With Fire?
The summer and fall promise to extend a long run of worsening years for American wildfires — fires that are projected to be fueled more by climate change. The unique weather and landscapes of the American West usher in regular wildfires. Drought and heat wrought by stubborn ocean conditions have left great stretches of it dryer and more combustible than usual this year. Experts say the keys to adapting Western lives to these wildfire risks lie in how fires and the lands that fuel them are managed; and in how yards, neighborhoods and cities are planned, built and run.
Scientific progress and more than a century of living with wildfire have boosted Western resilience to the threat. But improvements in how wildfire dangers have been managed have fallen far short of the reimaginations of landscapes that are needed. “We’ve made good progress, but not good enough,” Jan van Wagtendonk, a retired Yosemite National Park forest scientist who has documented the evolution of America’s management of wildfires, said. “Much more is needed.”
New study finds surprising culprit drives forest fire behavior
Taylor, A.H., Trouet, V., Skinner, C.N., Stephens, S. 2016. Socioecological transitions trigger fire regime shifts and modulate fire–climate interactions in the Sierra Nevada, USA, 1600–2015 CE. Proceedings of the National Academy of Sciences 113: 48(13684-13689). Doi: 10.1073/pnas.1609775113
Researchers across the United States collaborated to better understand the forces acting upon fire activity. Led by Alan Taylor from Pennsylvania State, the researchers combined tree-ring-based records of Sierra Nevada fire history with a 20th Century fire record based on annual area burned to develop a 415 year-long archive of fire activity. The study found that human activity, as opposed to climate change, has the greatest impact on forest fire behavior. The findings suggest that land managers and landowners can affect fire behavior through methods that make forest more resilient. The authors conclude that by changing land use, we can buffer some of the effects of climate change in forest fires.
Spatially explicit measurements of forest structure and fire behavior following restoration treatments in dry forests
Ziegler, J.P., Hoffman, C., Battaglia, M. and Mell, W., 2017. Spatially explicit measurements of forest structure and fire behavior following restoration treatments in dry forests. Forest Ecology and Management, 386, pp.1-12.
A new study from Colorado State University investigated the effect of forest restoration treatments on fire resiliency. Restoration treatments in dry forests often use silvicultural techniques in an attempt to rebuild historical characteristics of forest structure, however this has been known to cultivate a less complex forest structure due to the use of non-spatial metrics. Rather than building a complex forest structure similar to historical conditions, it is suggested that this treatment could lead to increased homogeneity in forest structure. The authors of this study explored fire behavior following these restoration treatments and found that the two objectives (fire reduction and altering forest structure complexity) were non-competing. Their results suggest that current restoration-based harvests can simultaneously fulfill objectives of altering structural complexity and of reducing fire behavior.
Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range
Cansler, C. Alina and Donald McKenzie. 2014. Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range, USA. Ecological Applications 24:1037–1056. http://dx.doi.org/10.1890/13-1077.1
This research examined relationships between climate and the annual area burned and the size of wildfires over a 25-year period. The study found significant positive relationships between climate and fire size, and between fire size and the proportion of high severity and spatial-pattern metrics that quantify the spatial aggregation of high-severity areas within fires, but the strength and significance of these relationships varied among the four subsections. In areas with more contiguous subalpine forests and less complex topography, the proportion and spatial aggregation of severely burned areas were more strongly correlated with fire size. If fire sizes increase in a warming climate, changes in the extent, severity, and spatial pattern of fire regimes are likely to be more pronounced in higher-severity fire regimes with less complex topography and more continuous fuels.
Firefighting blamed for 'megafires' ravaging US forests
So-called "megafires" are becoming increasingly common and destructive in the wildlands of the western United States. Could overzealous firefighting itself be to blame? BBC North America Correspondent, James Cook, interviews firefighters, conservation directors, ranchers and Tom Tidwell, chief of the US Forest Service to investigate.
An evaluation of the Forest Service Hazardous Fuels Treatment Program—Are we treating enough to promote resiliency or reduce hazard?
Vaillant, N.M. and Reinhardt, E.D. 2017. An Evaluation of the Forest Service Hazardous Fuels Treatment Program—Are We Treating Enough to Promote Resiliency or Reduce Hazard? Journal of Forestry 115: 83-97. DOI: 10.5849/jof.16-067
The National Cohesive Wildland Fire Management Strategy recognizes that wildfire is a necessary natural process in many ecosystems, and strives to reduce conflicts between fire-prone landscapes and people. In an effort to proactively mitigate potential negative wildfire impacts, the U.S. Forest Service reduces wildland fuels. As part of an internal program assessment, the authors of this study evaluated the extent of fuel treatments and wildfire occurrence within lands managed by the National Forest System (NFS) between 2008 and 2012. They found that, annually, 45% of NFS lands that would have historically burned were disturbed by fuel treatments and wildfire, indicating that NFS lands remain in a “disturbance deficit.” They also found that the highest wildfire hazard class had the lowest percentage of area treated and the highest proportion of both wildfire of any severity and uncharacteristically high-severity wildfire, suggesting that an alternative distribution of fuel treatment locations would likely improve program effectiveness.
Riparian fuel treatments in the western USA: Challenges and considerations
Dwire, Kathleen A.; Meyer, Kristen E.; Riegel, Gregg; Burton, Timothy. 2016. Riparian fuel treatments in the western USA: Challenges and considerations. Gen. Tech. Rep. RMRS-GTR-352. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 156 p.
A group of ecologists recently published a report examining the effect of fuel reduction treatments to watersheds on riparian ecosystems and the subsequent challenges and considerations for riparian management. The report first provides background on the impact of both fire and fire treatment on riparian species, and then shows the results of an online survey that asked resource managers about their current proposals and plans for fuel reduction treatments in watersheds. From the survey, the authors concluded that habitat restoration was a common objective for many fuel treatments being considered in riparian areas (watersheds). The authors emphasize that the integration of riparian fuel treatments with other aspects of fuel reduction management could lead to improved riparian condition in a range watershed ecosystems.
Fuel moisture sensitivity to temperature and precipitation changes
The authors of this paper examined the sensitivity of fuel moisture to changes in temperature and precipitation and explored the related implications of future climate. They used the Canadian Forest Fire Weather Index System components to represent the moisture content of fine surface fuels, upper forest floor layers and deep organic soils. They also obtained weather data from 12 stations across Canada for the fire season during the 1971–2000 period and used those data to create a set of modified weather streams by varying the daily temperatures and daily precipitation by set amounts while calculating fuel moistures for all temperature and precipitation combinations. They found that, for every degree of warming, precipitation had to increase by more than 15 % for surface fuels, about 10 % for upper forest floor layers and about 5 % for deep organic soils to compensate for the drying caused by warmer temperatures. Results from three General Circulation Models (GCMs) and three emission scenarios suggest that this sensitivity to temperature increases will result in a future with drier fuels and a higher frequency of extreme fire weather days.
Contemporary patterns of fire extent and severity in forests of the Pacific Northwest
Reilly, M.J., Dunn, C.J., Meigs, G.W., Spies, T.A., Kennedy, R.E., Bailey, J.D. and Briggs, K., 2017. Contemporary patterns of fire extent and severity in forests of the Pacific Northwest, USA (1985–2010). Ecosphere, 8(3):e01695. DOI 10.1002/ecs2.1695
A team of Oregon State University researchers and collaborators worked together to conduct a comprehensive examination of burn severity at all levels. They integrated Landsat time series data with field measurements of tree mortality to map burn severity in forests of the Pacific Northwest from 1985 to 2010. After examining temporal trends and spatial patterns of burn severity, they compared results among vegetation zones. Their results support concerns about large patches of high-severity fire in some dry forests. They also suggest that spatial patterns of burn severity are generally consistent with current understanding of historical landscape dynamics in the region. This study highlights the importance of considering the ecological effects of fire at all levels of severity in management and policy initiatives.
Recent mountain pine beetle outbreaks, wildfire severity, and postfire tree regeneration in the US Northern Rockies
Harvey, B.J.; Donato, D.C.; Turner, M.G. 2014. Recent mountain pine beetle outbreaks, wildfire severity, and postfire tree regeneration in the US Northern Rockies. PNAS. Online: http://www.eenews.net/assets/2014/09/29/document_pm_02.pdf
This study investigated the potential relationship between bark beetle outbreak and ecological severity of wildfire. Surprisingly the authors found no relation of recent (2001-2010) beetle outbreak to subsequent fire severity. Instead fire severity was driven primarily by extreme burning conditions (weather) and topography.
Where Wildfires and Climate Scientists Meet
Arthur Sedlacek is an atmospheric chemist trying to solve one of the biggest mysteries in global climate change: the role that wildfires play when they spew millions of tons of soot skyward each year. In 2013, Sedlacek was part of a team that flew into wildfire plumes in the Pacific Northwest and then Tennessee to measure exactly what’s in the soot. As the threat of global warming becomes increasingly pronounced, accurate measurements and correct predictive models are more essential than ever. But there’s a problem: When researchers incorporate the effects of greenhouse gases into their models, the outcome is an extremely hot Earth - too hot, explains Sedlacek. There must be some missing factor that cools the earth ever so slightly, but scientists haven’t figured out what it is. Sedlacek’s team thinks the likely culprit is aerosols. One of the biggest and least understood sources of aerosols is wildfire, which generates 40% of the carbon soot in the atmosphere. It’s a tricky problem because fires exert both warming and cooling effects on the climate. Black smoke billowing up from a fire’s center has a warming effect because dark aerosols absorb light, keeping that energy trapped in our atmosphere. But as winds push aerosols away from the fire, the particles gather a reflective coating of organic matter, which has a cooling effect.
Fighting wildfire in Idaho starts at home
A recent article in the Idaho Statesman connects Stephen Pyne’s work to the issues faced by homeowners in fire-prone areas of Idaho. In 2015, 740,000 acres of land in Idaho was burned by wildfire. Many of these wildfire complexes began as fires on private land and burned in a zone where fire is not managed by federal agencies, but by the state. Sam Bonovich, chief of the Clear Creek Fire Department, is working with a group of local Idahoan officials, federal and state foresters, timber companies, environmentalists, bikers, skiers, anglers and others on projects to thin and log the Idaho national forest around Robie Creek and Bogus Basin. Called the Bogus Basin Project, they hope to reduce the load of forest fuels that can power a conflagration. Consensus on the Bogus Basin project has been reached, and the U.S. Forest Service hopes to have a plan out for public comment soon, which would be the next in a series of steps to get the plan approved, funded and then into the forest. However, rather than waiting for this process to play out, many in the state, including Bonovich, want the Idaho Legislature to allocate funds for thinning and other fire-prevention projects, to go along with the millions of dollars Idaho taxpayers will end up paying for fighting fires this season.
Vulnerability of Bull Trout in the Face of Wildfires and Climate Change
Falke, J.A., Flitcroft, R.L., Dunham, J.B., McNyset, K.M., Hessburg, P.F., Reeves, G.H., 2014, Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape. DOI- 10.1139/cjfas-2014-0098: Canadian Journal Fisheries and Aquatic Sciences, p. online.
In the Pacific Northwest, climate change is anticipated to result in increased frequency, severity, and size of wildfires. Large and severe wildfires can lead to higher stream temperatures, affecting fish that rely on cold water to survive, such as the threatened bull trout. To address this issue, Oregon State University, U.S. Forest Service, and USGS researchers modeled population vulnerability of bull trout in the Wenatchee River, WA under current and future climate and fire scenarios. Analyses showed that local management, including reducing fire size and removing barriers to enhance fish population connectivity, can significantly reduce the vulnerability of bull trout to climate change. The Wenatchee River basin represents a unique configuration of threats, but many of the fundamental processes modeled occur across the range of bull trout and lessons learned may be useful in other locations.
Wildland fire emissions, carbon, and climate: Wildfire–climate interactions
Yongqiang Liu, Scott Goodrick, Warren Heilman, journal Forest Ecology and Management, Volume 317, Pages 1-96 (1 April 2014)
ncreasing wildfire activity in recent decades, partially related to extended droughts, along with concern over potential impacts of future climate change on fire activity has resulted in increased attention on fire–climate interactions. Findings from studies published in recent years have remarkably increased our understanding of fire–climate interactions and improved our capacity to delineate probable future climate change and impacts. Fires are projected to increase in many regions of the globe under a changing climate due to the greenhouse effect. Burned areas in the western US could increase by more than 50% by the middle of this century. Increased fire activity is not simply an outcome of the changing climate, but also a participant in the change. Smoke particles reduce overall solar radiation absorbed by the Earth’s atmosphere during individual fire events and fire seasons, leading to regional climate effects including reduction in surface temperature, suppression of cloud and precipitation, and enhancement of climate anomalies such as droughts. Black carbon (BC) in smoke particles displays some different radiation and climate effects by warming the middle and lower atmosphere, leading to a more stable atmosphere. BC also plays a key role in the smoke-snow feedback mechanism. Fire emissions of CO2, on the other hand, are an important atmospheric CO2 source and contribute substantially to the global greenhouse effect. Future studies should generate a global picture of all aspects of radiative forcing by smoke particles. Better knowledge is needed in space and time variability of smoke particles, evolution of smoke optical properties, estimation of smoke plume height and vertical profiles and their impacts on locations of warming layers, stability structure, clouds and smoke transport, quantification of BC emission factors and optical properties from different forest fuels, and BC’s individual and combined roles with organic carbon. Finally, understanding the short- and long-term greenhouse effect of fire CO2 emissions, increased capacity to project future fire trends (especially mega-fires), with consideration of climate–fuel–human interactions, and improved fire weather and climate prediction skills (including exploring the SST-fire relations) remain central knowledge needs.
Conservation Programs Take a Hit in Obama's USDA Spending Plan
The roughly $850 million in proposed cuts over five years in Agriculture Department conservation programs could undermine a much-touted regional model for improving water quality, reducing soil erosion and providing wildlife habitat without government regulation. The Obama administration's fiscal 2016 budget would cut 3 million acres from the Conservation Stewardship Program (CSP), a voluntary program that helps farmers and ranchers maintain and expand different conservation practices. The budget request would also cut back $373 million from the Environmental Quality Incentives Program (EQIP), which offers technical and financial assistance to landowners looking to change their practices. Both CSP and EQIP were authorized in the 2014 farm bill. "Pretty soon, there will be precious little left out of the conservation budget," said Ferd Hoefner, policy director for the National Sustainable Agriculture Coalition.
Mapping the health threat of wildfires under climate change
Jia Coco Liu, Loretta J. Mickley, Melissa P. Sulprizio, Francesca Dominici, Xu Yue, Keita Ebisu, Georgiana Brooke Anderson, Rafi F. A. Khan, Mercedes A. Bravo, Michelle L. Bell. Particulate air pollution from wildfires in the Western US under climate change. Climatic Change, 2016; DOI: 10.1007/s10584-016-1762-6
New research published in Climatic Change estimates the potential future impact of increased wildfires on air pollution and human health. Led by Yale University with collaborators from Harvard and Colorado State University, the study examined levels of fine particulate matter from past and future wildfires in 561 western U.S. counties. Findings showed that 82 million individuals will experience a 57% increase in frequency and a 31% increase in intensity of extreme air pollution (at least 2 consecutive days of increased particulate matter caused by wildfire) by mid-century. Out of the 561 counties, those in Northern California, Western Oregon and the Great Plains were projected to experience the highest exposure of wildfire smoke. Additionally, the authors created an interactive map to illustrate the counties likely to be affected by future air pollution due to wildfires. Access the Interactive Map here: http://khanotations.github.io/smoke-map/.
New tool to estimate fire risk
The new Fire Risk Estimation or FIRE tool, automatically processes satellite and weather station data—including temperature, precipitation, relative humidity, and wind observations—into a single measurement of fire potential. The tool, developed by the NOAA National Centers for Environmental Information, NASA DEVELOP National Program, and partners, aims to give fire managers an overall view of risk in different locations, helping them quickly decide when and where to allocate their resources.
Forest-Thinning could Help Prevent Destructive Fires
Washington DNR officials believe thinning and restoring more forests on public and private lands throughout the state could help prevent another wildfire season like 2014, the most destructive in state history. The DNR has requested a five-fold increase on the amount spent of forest hazard reduction over the next two years (a $20 million request). In 2012 the DNR made a similar $20 million request for forest health projects and received $4 million for thinning forests throughout the state. However, some lawmakers believe there will be stronger support for preventative measures this year following last year’s devastating fire season.
Area burned in the western United States unaffected by recent mountain pine beetle outbreaks
Hart, S.J., Schoennagel, T., Veblen, T.T., Chapman, T.B. 2015. Area burned in the western United States is unaffected by recent mountain pine beetle outbreaks. PNAS 112, 14, 4375-4380.
Mountain pine beetles have been a serious scourge in the Western US, leading to the death of pine trees across 71,000 cubic kilometers of forestland since the mid-1990s. As a result, it has been widely perceived that an abundance of dead fuels from the death of the pine trees might exacerbate fire behavior and lead to a wider area being burned. The authors of the study examined the effects of beetle outbreaks during the three peak years of wildfire activity since 2002 in the Western US and found that the effect was negligible. Although both fires and beetle outbreaks have increased due to warming temperatures, the occurrence of one does not seem to reinforce occurrence of the other.
Increasing western US forest wildfire activity: sensitivity to changes in the timing of spring
Westerling, A. L. (2016). Increasing western US forest wildfire activity: Sensitivity to changes in the timing of spring. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(1696), 20150178. doi:10.1098/rstb.2015.0178
Prior work shows western US forest wildfire activity increased abruptly in the mid-1980s. This study shows that the number of large forest fires and the areas burned within them have continued to increase in recent decades. Forests in the northern Rockies dominated early increases in wildfire activity, and still contributed 50% of the increase in large fires over the last decade. However, the percentage growth in wildfire activity in Pacific northwestern and southwestern forests has rapidly increased over the last two decades. Wildfire numbers and burned area have also increased in non-forested areas. This study shows that wildfire activity is strongly associated with warming and earlier spring snowmelt. Areas of forested lands with earlier spring snowmelt have been most greatly affected due to the loss of moisture.
Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States
Stavros, Natasha E. et al., Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States, Climatic Change, October 2014, Volume 126, Issue 3-4, pp 455-468, DOI 10.1007/s10584-014-1229-6
Seasonal changes in the climatic potential for very large wildfires (VLWF ≥ 50,000 ac ~ 20,234 ha) across the western contiguous United States are projected over the 21st century using generalized linear models and downscaled climate projections for two representative concentration pathways (RCPs). Significant (p ≤ 0.05) increases in VLWF probability for climate of the mid-21st century (2031–2060) relative to contemporary climate are found, for both RCP 4.5 and 8.5. The largest differences are in the Eastern Great Basin, Northern Rockies, Pacific Northwest, Rocky Mountains, and Southwest. Changes in seasonality and frequency of VLWFs d7epend on changes in the future climate space. For example, flammability-limited areas such as the Pacific Northwest show that (with high model agreement) the frequency of weeks with VLWFs in a given year is 2–2.7 more likely. However, frequency of weeks with at least one VLWF in fuel-limited systems like the Western Great Basin is 1.3 times more likely (with low model agreement). Thus, areas where fire is directly associated with hot and dry climate, as opposed to experiencing lagged effects from previous years, experience more change in the likelihood of VLWF in future projections. The results provide a quantitative foundation for management to mitigate the effects of VLWFs.
Diversity in forest management to reduce wildfire losses: implications for resilience
Charnley, S., T. A. Spies, A. M.G. Barros, E. M. White, and K. A. Olsen. 2017. Diversity in forest management to reduce wildfire losses: implications for resilience. Ecology and Society 22(1):22. https://doi.org/10.5751/ES-08753-220122
This study investigated how federal, state, and private forest owners in a fire-prone landscape of south-central Oregon manage their forests to reduce wildfire hazard and loss to high-severity wildfire. The authors evaluated the implications of their findings for insights into social–ecological resilience. They found a high degree of "response diversity" (variation in forest management decisions and behaviors) between and within groups. This response diversity contributed to heterogeneous forest conditions across the landscape. Modeling results indicated that, in general, U.S. Forest Service management had the most favorable outcomes for forest resilience to wildfire, and private corporate management the least. Heterogeneity in social–ecological systems is often thought to favor social–ecological resilience. However, this study found that, despite high social and ecological heterogeneity, most forest ownerships do not exhibit characteristics that make them resilient to high-severity fire. The coupled human and natural systems approach used here gave insights into connections among the social, economic, and ecological components of a multi-ownership, fire-prone ecosystem, and helped identify interventions to improve social–ecological resilience to wildfire.
Wildfire policies should incorporate more prescribed and natural burns
North MP, Stephens SL, Collins BM, Agee JK, Aplet G, Franklin JF, Fule PZ (2015) Reform forest fire management: Agency incentives undermine policy effectiveness. Science 349, 6254: 1280-1281. doi: 10.1126/science.aab2356
A new commentary published in the journal Science by a team of researchers from the University of Washington, UC-Berkeley, Northern Arizona University, The Wilderness Society and the Forest Service argues for the reform of forest fire management due to the fire conditions that now exist (due to changes in climate). The authors advocate for more prescribed and managed burns, tree thinning and less frequent suppression of burns in certain conditions. Parks Canada, which divides land into different zones for different types of fire management, could be a model for US fire management. If this approach were to be taken, the authors argue that forests in the Cascades and Sierra Nevada could be restored to a more natural state where ignition would not occur as frequently and thus fires would be much less severe.
Issues with fire suppression
Paveglio, T. B., Carroll, M. S., Hall, T. E., & Brenkert-Smith, H. (2015). ‘Put the wet stuff on the hot stuff’: The legacy and drivers of conflict surrounding wildfire suppression. Journal of Rural Studies, 41, 72-81.
A new study examines the social dynamics that influence conflict among local residents and outside professionals involved in wildfire management or suppression. Interviews were conducted with local residents of a southeastern Washington community in 2012 to better understand conflict surrounding wildfire management of the 2006 Columbia Complex fire. The results of this study demonstrated that conflict stemmed from differences in the norms characterizing the local community and the established practices of outside firefighters, the inability of these two groups to communicate in a way that established shared meanings for values at risk, and local residents’ desire to contribute to suppression efforts rather than give up complete control to outside resources. In addition to these sources of conflict, the authors extend their research to examine the long-term legacy of conflict surrounding the Columbia Complex fire. This included increased distrust of externally based fire response and entrenched views about locals’ right to protect their property. The study concluded by discussing the need to account for the legacy of conflict during future wildfire events and the reasons such conflict are likely to arise in rural or agricultural communities.
Bridging the gap: Joint Fire Science Program outcomes
Barret, S.W. 2017. Bridging the gap: Joint Fire Science Program outcomes. Fire Science Digest, 24, pp.1-12.
The Northwest Fire Science Consortium recently published a report summarizing studies that assess the effectiveness of research projects funded by the Joint Fire Science Program (JFSP). These studies identified several issues. In response to barriers to collaborative efforts, the Fire Science Exchange Network was established to facilitate communication between managers and researchers. Though JFSP-funded research is currently being used for planning, other barriers continue to prevent greater use of fire science information by the broader fire management community. JFSP aims to utilize the results of these studies to continue the iterative process of improvement.
Recent advances and remaining uncertainties in resolving past and future climate effects on global fire activity
Williams, A.P., Abatzoglou, J.T. 2016. Recent Advances and Remaining Uncertainties in Resolving Past and Future Climate Effects on Global Fire Activity. Current Climate Change Reports. DOI: 10.1007/s40641-016-0031-0
Scientists Alton Williams and John Abatzoglou recently published a synthesis report on the current advances and uncertainties surrounding the effects of climate on global fire activity. The authors first discussed recent scientific advances toward the discovery of a positive relationship between fire activity and aridity, noting an observed increase in both over the past several decades and the subsequent consequences anthropogenic effects may have on global fire regimes and the terrestrial biosphere. The authors then examined the various models used to study future fire responses to climate change. They described the specific uses for macro-scale models, correlation-based models, and process-based models. The synthesis also emphasized the observation-based research that must continue in order to evaluate interactions between fire, vegetation, climate, and humans.
Climate and very large wildland fires in the contiguous western USA
Stavros, E.N., J. Abatzoglou, N. Larkin, D. McKenzie, and E.A. Steel. 2014. Climate and very large wildland fires in the contiguous western USA. International Journal of Wildland Fire 23(7): 899-914, http://dx.doi.org/10.1071/WF13169.
Very large wildfires can cause significant economic and environmental damage, including destruction of homes, adverse air quality, firefighting costs and loss of life. This study examines how climate is associated with very large wildland fires (VLWFs) in the western contiguous USA. The authors used composite records of climate and fire to investigate VLWF–climatic relationships. Results showed quantifiable fire weather leading up to VLWFs, thus providing predictors of the probability that VLWF occurrence in a given week. Fire weather predictors of VLWFs vary by region, suggesting that broad-scale ecological mechanisms associated with wildfires also vary by regions. This analysis provides a means for anticipating VLWFs specifically and thereby the timing of substantial area burned within a given year, thus providing a quantifiable justification for proactive fire management practices to mitigate the risk and associated damage of VLWFs.
Regional patterns of post-wildfire streamflow response in the Western U.S.
Hallema, D.W., Sun, G., Bladon, K.D., Norman, S.P., Caldwell, P.V., Liu, Y. and McNulty, S.G. In press. Regional Patterns of Post‐Wildfire Streamflow Response in the Western United States: The Importance of Scale‐Specific Connectivity. Hydrological Processes. DOI: 10.1002/hyp.11208.
A team of scientists published this review to highlight the effects of wildfire on hydrological processes. They specifically focus on regional differences in how streamflow responds in forests after a wildfire. They found that post-wildfire peak flows and annual water yields are generally higher in regions with a Mediterranean or semi-arid climate (Southern California and the Southwest) compared to the highlands (Rocky Mountains and the Pacific Northwest). Through their research, they emphasize that understanding the effects of hydrological processes on post-wildfire dynamic hydraulic connectivity is necessary for risk assessment tools. This is particularly true at the hillslope and watershed scales, and the relationship between overlapping disturbances, including those other than wildfire.
Restoring fire-prone Inland Pacific landscapes
Hessburg, P.F., Churchill, D.J., Larson, A.J., Haugo, R.D., Miller, C., Spies, T.A., North, M.P., Povak, N.A., Belote, R.T., Singleton, P.H. and Gaines, W.L. 2015. Restoring fire-prone Inland Pacific landscapes: seven core principles. Landscape Ecology, 30(10), pp.1-31.
A new study provides a framework for landscape restoration and discusses its implication for land management. Scientists identified key characteristics of historical forests and applied them to present land management efforts. The study found that historical forests were spatially heterogeneous at multiple scales. Heterogeneity was the result of variability and interactions among native ecological patterns and processes, including processes regulated by climatic and topographic drivers. Native flora and fauna were adapted to these conditions, giving them resilience to climate variability and recurrent contagious disturbances. The authors conclude by outlining how such resilience can be restored to our current landscapes. They stress the need for planning and management on multiple scales, as well as the need for active thinking about landscapes as socio-ecological systems that provide services to people. The study focuses attention on landscape-level prescriptions as foundational to restoration planning and execution.
Temperate and boreal forest mega-fires: characteristics and challenges
Stephens, Scott L.; Burrows, Neil; Buyantuyev, Alexander; Gray, Robert W.; Keane, Robert E.; Kubian, Rick; Liu, Shirong; Seijo, Francisco; Shu, Lifu; Tolhurst, Kevin G.; Ivan Wagtendonk, Jan W. 2014. Temperate and boreal forest mega-fires: characteristics and challenges. Frontiers in Ecology and the Environment. 12: 115-122. Online: http://www.treesearch.fs.fed.us/pubs/47021.
Three factors - climate change, fire exclusion, and antecedent disturbance, collectively referred to as the "mega-fire triangle" - likely contribute to today's mega-fires. Some characteristics of mega-fires may emulate historical fire regimes and can therefore sustain healthy fire-prone ecosystems, but other attributes decrease ecosystem resiliency. A good example of a program that seeks to mitigate mega-fires is located in Western Australia, where prescribed burning reduces wildfire intensity while conserving ecosystems. Fire and forest managers should recognize that mega-fires will be a part of future wildland fire regimes and should develop strategies to reduce their undesired impacts.
Vegetation, Topography and Daily Weather Influenced Burn Severity in Idaho and Montana Forests
Donovan S. Birch, Penelope Morgan, Crystal A. Kolden, John T. Abatzoglou, Gregory K. Dillon, Andrew T. Hudak, and Alistair M. S. Smith 2015. Vegetation, topography and daily weather influenced burn severity in central Idaho and western Montana forests. Ecosphere 6(1):17. http://dx.doi.org/10.1890/ES14-00213.1
Burn severity as inferred from satellite-derived differenced Normalized Burn Ratio (dNBR) is useful for evaluating fire impacts on ecosystems but the environmental controls on burn severity across large forest fires are both poorly understood and likely to be different than those influencing fire extent. We related dNBR to environmental variables including vegetation, topography, fire danger indices, and daily weather for daily areas burned on 42 large forest fires in central Idaho and western Montana. We found that percent existing vegetation cover had the largest influence on burn severity, while weather variables like fine fuel moisture, relative humidity, and wind speed were also influential but somewhat less important. We posit that, in contrast to the strong influence of climate and weather on fire extent, ‘‘bottom-up’’ factors such as topography and vegetation have the most influence on burn severity. While climate and weather certainly interact with the landscape to affect burn severity, pre-fire vegetation conditions due to prior disturbance and management strongly affect vegetation response even when large areas burn quickly.
Wildfires Pose Risk to Nearly 900,000 Homes in the Western U.S
Nearly 900,000 homes across 13 states in the western U.S. are currently designated at “High” or “Very High” risk for wildfire damage, representing a combined total reconstruction value estimated at more than $237 billion. Of the total homes identified, just over 192,000 homes fall into the “Very High Risk” category alone, with total reconstruction cost valued at more than $49.6 billion. The analysis also assigns a numeric risk score to each property, ranging from 1 to 100. This separate score indicates the level of susceptibility to wildfire, as well as the risk associated with the property being located in close proximity to another high-risk property or area. The score designation is important since wildfire can easily expand to adjacent properties and cause significant damage even if that property was not originally considered high risk.
Lack of Snowpack Could Mean Early Central Oregon Fire Season
A warm winter with light snowfall in the mountains near Bend means wildfire season could come early. Timber fires do not typically occur in Central Oregon until August, said Ed Keith, Deschutes County forester, but the lack of snow may lead to big blazes earlier. “This year it may be June or July,” he said. The Deschutes/Crooked River Basin snowpack was only 9 percent of normal for this time of year, according to the Natural Resources Conservation Service. Many of the automated snow sites monitored by the federal agency report no snow for the first time in three decades of recording data. A year ago the basin had 54 percent of the normal snowpack on March 20. “We are gaining some precipitation now, which will help,” said Rachel Cobb, a Weather Service meteorologist in Pendleton, “but I don’t know if it will be enough to make up for what we didn’t get over the winter.”
Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States
C. Alina Cansler and Donald McKenzie 2014. Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range, USA. Ecological Applications 24:1037–1056. doi: http://dx.doi.org/10.1890/13-1077.1
Researchers evaluated changes in the climatic potential for very large wildfires (VLWF) across the western United States during the 21st century by using generalized linear models and downscaled climate projections for two representative concentration pathways. There was a significant increase in the potential for VLWF between contemporary climate and mid-century climate (2031-2060). The Pacific Northwest, Northern Rockies, Rocky Mountains, Eastern Great Basin, and Southwest are the regions that show the greatest increase in the probability of a VLWF over time. Determining the frequency and the seasonality of VLFW is heavily dependent on future climate space. The results and projections of this study can be used for form new fire policy and by serve as a baseline for policy and management.
Climate Change Refugia, Fire Ecology and Management
Wilkin, K.M., D.D. Ackerly and S.L. Stephens. 2016. Climate Change Refugia, Fire Ecology and Management. Forests, 77(7).
Refugia are habitats that buffer climate changes and allow species to persist in—and to potentially expand under—changing environmental conditions. This paper suggests that cold-air pools (areas with lower temperatures and higher moisture) act as an important type of small-scale refugia, having fewer fires and fires of lower severity. Active management, such as restoration and fuels treatments for climate change adaptation, may be required to maintain these distinctive and potentially important refugia. Interestingly while overall temperatures are increasing the weather patterns that cause cool-air pooling at the landscape scale are increasing, at least in the Sierra Nevadas, so the frequency and duration of cold-air pools may actually increase with climate change.
Climate and Fires Tightly Linked Over the Past Century in the Northern Rocky Mountains
Higuera, P.E., Abatzoglou, J.T., Littell, J.S. and Morgan, P. 2015. The changing strength and nature of fire-climate relationships in the northern Rocky Mountains, U.S.A., 1902-2008. PLoS ONE 10(6): e0127563. doi:10.1371/journal.pone.0127563
A new paper by a team of University of Idaho and U.S. Geological Survey scientists suggests that climate strongly influences wildfire activity in the northern Rocky Mountains, despite large changes in forest management and fire suppression.
Increases in wildfires over the past 30 years coincide with an increase in warm, dry summer conditions, according to the study. The same is true for a period in the early 20th century, including the dramatic fires of 1910. During a cooler, wetter period in the mid-20th century, fire activity decreased. The team compared fire patterns found in previously published records of burned areas in Idaho and western Montana with seasonal climate records to reveal the flammability of forest vegetation.
Using an agent-based model to examine forest management outcomes in a fire-prone landscape in Oregon, USA
Spies, T. A., E. White, A. Ager, J. D. Kline, J. P. Bolte, E. K. Platt, K. A. Olsen, R. J. Pabst, A. M.G. Barros, J. D. Bailey, S. Charnley, J. Koch, M. M. Steen-Adams, P. H. Singleton, J. Sulzman, C. Schwartz, and B. Csuti. 2017. Using an agent-based model to examine forest management outcomes in a fire-prone landscape in Oregon, USA. Ecology and Society 22(1):25.
Authors used a coupled human and natural systems framework and an agent-based landscape model to examine how alternative management scenarios affect fire and ecosystem services in a fire-prone multi-ownership landscape in the eastern Cascades of Oregon. Their model combined existing models of vegetation succession and fire spread with information from original empirical studies of landowner decision making. Results indicated that alternative management strategies can have variable effects on landscape outcomes over 50 years for fire, socioeconomic, and ecosystem services metrics. Federal restoration treatments slightly reduced threat various from fire, particularly in years with more fire. Under the current management scenario, timber production could be maintained for at least 50 years on federal lands. Under an accelerated restoration scenario, timber production fell because of a shortage of areas meeting current stand structure treatment targets. Trade-offs were evident between restoration goals (e.g., open forests with large fire-resistant trees) and protecting habitat for species that require dense older forests. For example, the proportional area of nesting habitat for northern spotted owl (Strix occidentalis) was somewhat reduced after 50 years under the restoration scenarios as compared to no management. However, the amount of resilient older forest structure and habitat for white-headed woodpecker (Leuconotopicus albolarvatus) was higher after 50 years under active management. More carbon was stored on this landscape without management than with management, despite the occurrence of high-severity wildfire. The authors suggest that further applications of their model could facilitate the development of policies and practices for fire-prone landscapes.
Insights from wildfire science: A resource for fire policy discussions
A team of wildfire experts have produced a report of key science insights that can aid in public discussion on wildfire policy. The authors detail seven important concepts and highlight relevant publications. These key insights promote scientifically sound discussion for those engaging in wildfire discourse, with the hope of informing future wildfire policy.
Influence of fire disturbance and biophysical heterogeneity on pre-settlement ponderosa pine and mixed conifer forests
Johnston, J. D., J. D. Bailey, and C. J. Dunn. 2016. Influence of fire disturbance and biophysical heterogeneity on pre-settlement ponderosa pine and mixed conifer forests. Ecosphere 7(11):e01581. 10.1002/ecs2.1581
Researchers from Oregon State University studied the relative influence of fire frequency, climate, soils, and topography on forests in Oregon’s southern Blue Mountains. Recently published in the journal Ecosphere, the study describes the relative influence of these variables on forest sites spanning a broad range of productivity. The researchers found that topographic position and vapor pressure deficit were stronger forces acting upon site-scale forest structure and composition than fire frequency. Within sites, however, soil water was the most important influence. Finally, the study concluded that frequent fire had a uniform influence across all forest dynamics, suggesting that management plans to reduce fuel and restore frequent fires is appropriate across all sites in the southern Blue Mountains.
New practitioners’ guide to modifying and applying spatial data for local use
LANDFIRE’s suite of spatial data layers is a valuable resource for land managers because they stretch “wall-to-wall” across the U.S.; are created with a consistent methodology; and are updated over time. The data are designed to support broad-scale land management activities, and users are encouraged to critique and modify them as needed for local application. The new guide Modifying LANDFIRE Geospatial Data for Local Applications (Helmbrecht and Blankenship, 2016) provides an easy-to-understand introduction to each of the LANDFIRE products; explains where and how to look for common problems with the data; and offers guidance on how to complete common modification tasks. This guide is an excellent resource for anyone working with LANDFIRE data, but will be especially helpful to users who need to refine the data for local application.
Improving forest sampling strategies for assessment of fuel reduction burning
Gharun, M.; Possell M.; Jenkins, M.E.; Poon, L.F.; Bell, T.L. & Adams, M.A. 2017. Improving forest sampling strategies for assessment of fuel reduction burning. Forest Ecology and Management 392, 78–89. https://doi.org/10.1016/j.foreco.2017.03.001
Land managers typically make post hoc assessments of the effectiveness of fuel reduction burning (FRB), but often lack a rigorous sampling framework. A general, but untested, assumption is that variability in soil and fuel properties increases from small (∼1 m) to large spatial scales (∼10–100 km). The authors of this study found that measurement variability does not increase with scale for all fuel components. They also found support for the hypothesis that site stratification could reduce variability between sampling plots and the required number of sampling plots, leading to cost savings. They conclude with recommendations on how sampling schemes can be improved for assessment of fuel reduction burning.
To make forests more climate resilient, we need to let some fires burn
Boisramé, G., Thompson, S., Collins, B. et al. 2016. Managed wildfire effects on forest resilience and water in the Sierra Nevada. Ecosystems doi:10.1007/s10021-016-0048-1
A report from the University of California, Berkeley, recently published in the journal Ecosystems, assessed the success of managed wildfire as a forest management technique. The authors studied the vegetation, water, and forest resilience of Illilouette Creek Basin in Yosemite National Park, a 40,000 acre valley that has experienced managed wildfire for four decades. The study found that, since managed wildfire policies had been implemented, the valley had more heterogeneous land cover, a lower fire risk, and higher resilience to both fire and drought.
Modifying LANDFIRE geospatial data for local applications
Helmbrecht, D.J. and Blankenship, K. 2016. Modifying LANDFIRE Geospatial Data for Local Applications. General Technical Report. 75 pp.
With the support of several collaborators, two fire ecologists developed a guide providing direction on the critique and modification of LANDFIRE geospatial data products for local applications. LANDFIRE data is often used for wildland fire and land management planning applications as it provides “wall-to-wall” geospatial data of vegetation, wildland fuel, fire regime, disturbance, and topographic characteristics for the United States. This guide presents primary considerations for using and modifying the data for use in local applications. It also provides examples and demonstrations of available tools and methods for completing common critique and modification tasks.
A spatial database of wildfires in the United States, 1992-2011
Short, K.C. 2014. A spatial database of wildfires in the United States, 1992-2011. Earth System Science Data. 6: 1-27. Online: http://www.treesearch.fs.fed.us/pubs/45689.
This project represents an attempt to acquire, standardize, error-check, compile, scrub, and evaluate the completeness of US federal, state, and local wildfire records from 1992-2011 for the national, interagency Fire Program Analysis (FPA) application. The resulting FPA Fire-Occurrence Database (FPA FOD) includes nearly 1.6 million records from the 20-year period, with information about location, discovery date, and final fire size. While necessarily incomplete in some aspects, the database is intended to facilitate fairly high-resolution geospatial analysis of US wildfire activity over the past two decades, based on available information from the authoritative systems of record.
Area Burned in the Western US is Unaffected by Recent Mountain Pine Beetle Outbreaks
Hart, S.J., Schoennagel, T., Veblen, T.T., Chapman, T.B. 2015. Area burned in the western United States in unaffected by recent mountain pine beetle outbreaks. PNAS, 112(14): 4375-4380. http://bit.ly/1PjKKqn
Across western North America, abundant susceptible pine hosts and a suitable climate during the early 21st century have promoted widespread mountain pine beetle (MPB) outbreaks, leading to concern that dead fuels may increase wildfire risk. The assumption that outbreaks raise fire risk is driving far-reaching policy decisions involving expenditures of hundreds of millions of dollars. Contrary to the expectation that an MPB outbreak increases fire risk, spatial overlay analysis shows no effect of outbreaks on subsequent area burned during years of extreme burning across the West. These results refute the assumption that increased bark beetle activity has increased area burned; therefore, policy discussions should focus on societal adaptation to the effects of the underlying drivers: warmer temperatures and increased drought.
Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States
Stavros, E.N.; Abatzoglou, J.T.; McKenzie, D.; Larkin, N.K. 2014. Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States. Climatic Change.
http://link.springer.com/article/10.1007%2Fs10584-014-1229-6 DOI 10.1007/s10584-014-1229-6
Seasonal changes in the climatic potential for very large wildfires across the western contiguous United States are projected over the 21st century. The probability of large wildfires will likely increase under multiple climate scenarios. Modelng suggests the largest increases will be in the Eastern Great Basin, Northern Rocki