NW Climate Science Digest

Aquatic Resources, Stream Flow, Hydrology in the Western U.S.

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.

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.

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.

Arid Ecosystems

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.

Biodiversity/Species and Ecosystem Response

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.

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.

Climate and Weather Reports and Services

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.

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.

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.

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

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.

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.

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.


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.

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.

Impact of anthropogenic climate change on wildfire across western U.S. forests

Abatzoglou, J.T., and Williams, A.P. 2016. Impact of anthropogenic climate change on wildfire across western US forests. Proceedings of the National Academy of Sciences, 113(42): 11770-11775. DOI: 10.1073/pnas.1607171113

Climate scientist John Abatzoglou from the University of Idaho and his colleague Alton Williams from Columbia University recently published a their report on the estimated contribution of anthropogenic climate change to the observed increase in fuel aridity metrics and forest fire area across the western U.S. The authors found that fuel aridity over the past several decades was significantly enhanced by anthropogenic increases in air temperature and vapor pressure deficits. Additionally, they found that anthropogenic climate change contributed to 75% more forested area that experienced high fire-season fuel aridity and increased days of high fire potential during 2000-2014, as well as a near doubling of forest fire area between 1984-2015 (adding 4.2 million ha). These findings show anthropogenic climate change as a driver of increased forest fire activity. The authors additionally conclude that natural climate variability will continue to fluctuate between mediating and compounding anthropogenic increases in fuel aridity.


Forest impacts on snow accumulation and ablation across an elevation gradient in a temperate montane environment

Roth, T. R. and Nolin, A. W. 2016. Forest impacts on snow accumulation and ablation across an elevation gradient in a temperate montane environment. Hydrol. Earth Syst. Sci. Discuss. doi:10.5194/hess-2016-529, in review.

Scientists from Oregon State University, Travis Roth and Anne Nolin, recently published a 4-year study examining snow-forest interactions in the Oregon Cascades in order to gain a better understanding of how forest canopies and sub-canopies modify snow accumulation and ablation rates. The researchers compared snow and meteorological measurements between forested and open sites across three elevations (Low, Mid and High seasonal snow zones). They found that the warmer, denser forests at Low and Mid sites buffered snow accumulation via increased canopy snow interception and increased energy inputs to the sub-canopy snowpack. These sites also exhibited shallower and shorter snowpacks compared to open sites at the same elevations (Low and Mid). Conversely, this relationship between open and forested sites is flipped at the High elevation, where forested sites maintain snow longer than in the open sites. Further findings show that open sites at High elevations experience high wind speeds and thus increased snow sublimation. The authors conclude by emphasizing the importance of improving forest cover model representations to accurately predict water resources in maritime forests

Draft Northwest Forest Plan (NWFP) science synthesis is now available online

The draft of the Northwest Forest Plan science synthesis is now available for review and public input. The draft synthesis is currently undergoing peer review coordinated by the Ecological Society of America. The U.S. Forest Service’s Pacific Northwest and Pacific Southwest Research Stations developed the draft synthesis, which, when finalized, will help to provide a scientific foundation for land management plans for 17 national forests within the NWFP area. Written by 45 scientists from the Forest Service, other federal agencies, universities, and tribes, the synthesis provides a review of the relevant scientific literature pertaining to key resource management topics within the NWFP area. The public can provide input on the science content of the draft synthesis to the group of independent peer reviewers in two ways: (1) Upload written input via and (2) Attend a public forum in Portland, Oregon on December 6, 2016, from 8:30 a.m. to 1:00 p.m. at the Doubletree by Hilton Portland. The forum will also be broadcast live as a webinar, so interested parties outside of the Portland commuting area can participate. Additional information and a detailed agenda can be found here.

Large forest die-offs can have effects that ricochet to distant ecosystems

Garcia ES, Swann ALS, Villegas JC, Breshears DD, Law DJ, Saleska SR, et al. (2016) Synergistic Ecoclimate Teleconnections from Forest Loss in Different Regions Structure Global Ecological Responses. PLoS ONE 11(11): e0165042. doi:10.1371/journal.pone.0165042

A recently published study led by scientists from the University of Washington identified areas of climate and vegetation change caused by “ecoclimate teleconnections”: climatic changes from a different region of the globe. In this case, the authors focused on forest loss in two regions: large-scale forest die-offs in western North America, and large-scale deforestation in the Amazon basin. The authors used global climate model simulations to estimate the distribution of ecologically-relevant climate changes resulting from forest loss. Interestingly, the results varied depending on whether the two regions were simultaneously simulated or separately combined. Simultaneous simulations showed (1) an increase in productivity in eastern South America due to forest loss causing the region to become cooler and wetter, and (2) a decrease in productivity in Eurasia, around Siberia,due to cooler temperatures which increased soil ice volume. The authors conclude the study by stressing the critical nature of researching “ecoclimate teleconnections” in order to understand the full scope of local changes.

Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir

Ford, K.R., Harrington, C.A., Bansal, S., Gould, P.J., and St. Clair, B. 2016. Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir. Blackwell Science, 22(11): 3712-3723. DOI: 10.1111/gcb.13328

A report by scientists from the United States Geologic Survey examined the effect of anthropogenic increases in temperature on the phenology of coast Douglas-fir trees. The authors modeled the timing of height-growth initiation and diameter-growth initiation in coast Douglas-fir using data from field-based and controlled-environment studies. This method gave the authors a wide range of data that included conditions warmer than those currently ecperinecded in the coast Douglas-fir tree range. For high latitude and elevation portions of the tree’s range, the study predicted that warming will lead to earlier growth initiation without substantial disturbance to the tree’s livelihood. Conversely, lower latitude and elevation areas of coast Douglas-fir habitat were predicted to experience delayed growth initiation due to the lack of exposure to cool temperatures which causes the tree to readily initiate growth in the spring. These findings suggest that the warmer edges of the tree’s distribution could experience reduced resilience under climate change.

Land Use

Global wheat production will decrease by more than five percent with each 1°C increase in global temperature

Bing Liu et al. 2016. Similar estimates of temperature impacts on global wheat yield by three independent methods. Nature Climate Change, 6 (12): 1130 DOI: 10.1038/nclimate3115

An international team of scientists recently collaborated to synthesize the findings of multiple studies on the potential impact of climate change on global crop yield. The authors show that estimates of temperature impact on wheat yields at global and national scales are similar across a wide range of climate models (grid-based and point-based simulations, and statistical regressions, all without deliberate adaptation or CO2 fertilization effects). The authors stress the importance of conducting multi-simulation-method ensembles in order to ensure the level of model and method uncertainty. This multi-method ensemble indicated a global wheat yield decline between 4.1 and 6.4% with a 1 °C global temperature increase. The models were also consistent concerning regional differences, showing warmer regions to likely suffer more yield loss than cooler regions.

The Northwest Climate Hub announces the availability of the Seedlot Selection Tool

The Seedlot Selection Tool (SST) is a web-based mapping application designed to help natural resource managers match seedlots (tree seed sources of known identification and source location) with planting sites based on climatic information. The SST can be used to map current climates or future climates based on selected climate change scenarios. It is tailored for matching seedlots and planting sites, but can be used by anyone interested in mapping climates defined by temperature and water availability. The SST is most valuable as a planning and educational tool because of the uncertainty associated with climate interpolation models and climate change projections. The SST allows the user to control many input parameters, and can be customized for the management practices, climate change assumptions, and risk tolerance of the user.

Special Reports / Announcements

The global climate 2011-2015: Hottest five-year period on record

The World Meteorological Organization has released a report on the hottest five-year period on record, the global climate between 2011-2015. The report gives detailed information on the status of global temperature, oceans, greenhouse gas concentrations, ice and snow cover, extreme weather, and humanitarian crises. The assessment also outlines the impending danger and cost of these impacts.

Taking Action

Reducing emissions from agriculture to meet the 2 °C target

Eva Wollenberg 2016. Reducing emissions from agriculture to meet the 2 °C target. Glob Change Biol, 22: 3859–3864. doi:10.1111/gcb.13340

An international team of scientists have identified a global target for reducing emissions from agriculture to stay below the agreed upon 2 °C warming limit. This global agriculture reduction target is 1 GtCO2e/yr by 2030, however the current mitigation pathways deliver only 21-40% of this target reduction. This paper published in Global Change Biology discusses the necessary improvements to mitigation pathways that are required to stay below the 2 °C limit.

A how-to guide for co-production of actionable science

Paul Beier of Northern Arizona University, Lara Hansen of EcoAdapt, Lynn Helbrecht of Washington Department of Fish and Wildlife and David Bhar of San Francisco Public Utilities Commission recently published a paper outlining a set of ten best practices for the co-production of science. The practices they recommend include seven intended to help scientists, managers, funders and other stakeholders carry out a coproduction project; one designed to ensure that partners learn from attempts at coproduction; and two aimed at promoting coproduction at a programmatic level. Combined, the ten recommended practices focus research on necessary decisions; give priority to processes and outcomes over stand-alone products; and allocate resources to organizations and individuals that engage in coproduction. Although this article focuses on the coproduction of actionable science for climate change adaptation and natural resource management, the approach is also relevant to other complex natural-human systems.

Landmark U.S. federal climate lawsuit

In 2015, twenty-one youth from across the United States, age 8 to 19, filed a landmark constitutional climate change lawsuit against the federal government in the U.S. District Court for the District of Oregon. In Juliana v. United States of America, the Plaintiffs claim that the federal government, having failed to take action against burning fossil fuels, has violated their constitutional rights to life, liberty, property, as well as failed to protect essential public trust resources. On April 8, 2016, U.S. Magistrate Judge Thomas Coffin ruled in favor of the young Plaintiffs by denying the government and fossil fuel industry's motions to dismiss. While the ruling was a major victory for the Plaintiffs, it is now under review by U.S. District Court Judge Ann Aiken, who heard oral arguments on September 13, 2016. On November 10, 2016 Judge Aiken issued an order that denied both the fossil fuel industry's and the federal government's motions to dismiss this case, officially giving the youth standing in court.

Tribal and Indigenous Peoples Matters

Climate change and indigenous peoples: a synthesis of current impacts and experiences

Norton-Smith et al. 2016. Climate change and indigenous peoples: a synthesis of current impacts and experiences. Gen. Tech. Rep. PNW-GTR-944. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 136 p.

The USDA Forest Service recently released a new report synthesizing our current understanding of how climate change impacts the sovereignty, culture, health, and economies of indigenous peoples. The report first outlines key frameworks for structuring indigenous interactions with climate change impacts and adaptation pathways. These frameworks include tribal sovereignty and self-determination, culture and cultural identity, and indigenous community health indicators. The report then provides a synthesis of climate knowledge, science, and strategies that indigenous communities are currently approaching. Each section of the report has specific findings for Northwest tribes. Read the report to find specific regional information.

Climate change and our natural resources

A Report from the Treaty Tribes in Western Washington: On November 15, 2016, the treaty tribes in western Washington released a comprehensive report on how climate change is hurting tribal treaty rights and natural resources. This report from the 20-member tribes of the Northwest Indian Fisheries Commission focuses on the impacts of climate change to our homelands, waters, and ways of life. http://nwtreatytribes.org/climatechange/.