NW Climate Science Digest

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

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.

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. 

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. 

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.

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. 

Biodiversity/Species and Ecosystem Response

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.

Climate and Weather Reports and Services

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.

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

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. 

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.

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.


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.

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.

The climate–wildfire–air quality system: interactions and feedbacks across spatial and temporal scales

Stavros, E. N., McKenzie, D. and Larkin, N. (2014), The climate–wildfire–air quality system: interactions and feedbacks across spatial and temporal scales. WIREs Clim Change, 5: 719–733. doi: 10.1002/wcc.303 http://onlinelibrary.wiley.com/doi/10.1002/wcc.303/abstract

Wildfire is a major source of air-quality impact in some areas, and a substantial contributor to pollutants of concern, including nitrogen oxides and particulate matter, which are regulated to protect public and environmental health. Since climate change is expected to increase total area burned by wildfire, and wildfires affect air quality, which is regulated, there is a need to define and study climate, wildfire, and air quality as one system. This paper is a review of the interactions and feedbacks acting across space and time within the climate–wildfire–air quality system, providing a foundation for integrated modeling and for assessing the ecological and social impacts of this system and its broader ecological, social, and scientific implications.


Climate change impacts on the distribution and performance of plant species at Mount Rainier

A recent Ph.D. dissertation by Kevin Ford of the University of Washington (UW).  Ford identified important interactions of environmental factors that may alter the effects of climate change on the distribution and performance of plant species on Mount Rainier in surprising ways.

Climate drivers of Douglas-fir growth in the western United States

Another recent Ph.D. dissertation by Christina Restaino of UW examined the relationship between climate and growth in Douglas fir trees by combining growth data from Douglas fir across a range of habitats in the west with climate data from the Variable Infiltration Capacity Hydrologic Model.  Restaino found temperature to exert a top-down control on tree growth, regardless of the magnitude of precipitation. 

Tree communities rapidly alter soil microbial resistance and resilience to drought

Rivest D., A. Paquette, B. Shipley, P.B. Reich & C. Messier.  2014.  Tree communities rapidly alter soil microbial resistance and resilience to drought.  Functional Ecology. DOI: 10.1111/1365-2435.12364 http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12364/abstract

Researchers experimentally imposed drought stress on three 4-year old tree monocultures and two stands of mixed tree species to investigate soil biochemical properties and soil microbial drought tolerance.  They found that that tree communities influenced soil chemistry and microbial resistance and resilience mostly through leaf litter lignin content and mineralisable nitrogen. For example, plots sugar maple had lower soil microbial biomass carbon than comparable plots of tamarack. Ultimately tree species was more important than species mixture as the key driver of drought tolerance.  

Land Use

Impacts of climate change on dairy production

Bauman, Y., G.S. Mauger, T. Nennich, and E.P. Salathé. 2014. Impacts of climate change on dairy production. Professional Geographer. http://cses.washington.edu/db/pubs/abstract655.shtml

This study explores the losses in production and the economic consequences of increased heat stress on Holstein dairy cows based on current and projected temperatures and humidity levels in the U.S. Increased heat and humidity cause cows to eat less and expend more energy regulating their body temperature. As a result they have less energy and water available to produce milk. To determine future temperature and humidity, the authors use the output from climate models, and apply it to estimate dairy production losses in the U.S. The study covers the lower 48 U.S. states, and highlights 10 counties nationwide that characterize differences in sensitivity to warming across the country. Economic losses statewide are greatest in California, where farms are most numerous, but on a per cow basis, the losses are highest in Texas, Florida and Arizona. The Northwest remains a relatively good place for dairy production.

Special Reports / Announcements

The Northwest Climate Science Center releases annual report for fiscal year 2014

The NW CSC Annual Report for Fiscal Year 2014 (October 1, 2013– September 30, 2014) highlights major accomplishments in FY14 for the NW CSC in each of five core service areas- Executive, Science, Data, Communications, and Education and Training. The annual report also recognizes the hard work of the NW CSC's dedicated staff, academic colleagues, and regional partners.

New National Climate Change and Wildlife Science Center integrated search tool

The brand new NCCWSC Integrated Search allows users to find data and project information from the USGS Center for Integrated Data Analytics Geo Data Portal, the USGS ScienceBase catalog, and the University of Idaho’s Northwest Knowledge Network in one quick search.

The Intergovernmental Panel on Climate Change releases synthesis report for policymakers of fifth assessment

The synthesis and summary integrate the main points from about 3000 pages of material contained in the IPCC's three assessment reports issued over the past year.  The key purpose of the Synthesis Report and Summary for Policy Makers is to inform upcoming climate change meetings by world leaders. "The IPCC summary states clearly that global warming is happening, that humans have caused it, that it is already dangerous, and that the warming trend could be irreversible. It makes it clear that urgent emissions reductions are required in the very near future to keep warming below two degrees Celsius to avert the worst impacts of climate change. These include extreme weather, rising sea levels, and increased heat waves, flooding and droughts. The report also suggests climate change could aggravate violent conflicts and refugee problems and have a negative effect on food production.

New multimedia gallery and visualization tools from USGCRP & partners

GlobalChange.gov has developed a new multimedia gallery with graphics from various reports, including the 2014 National Climate Assessment. The gallery also contains a large number of global change visualization tools and resources from USGCRP member agencies.

Taking Action

President’s Task Force on Climate Preparedness and Resilience delivers recommendations

President Obama’s State, Local, and Tribal Leaders Task Force on Climate Preparedness and Resilience delivered its recommendations on ways the Federal Government can better support the needs of communities in preparing for a changing climate.  The Task Force, established November 2013, consists of 26 US governors, mayors, county officials, and tribal leaders, including Washington Governor Jay Inslee.  Task Force recommendations focus on opportunities to build climate preparedness and resilience in a variety of areas, including disaster recovery, infrastructure investment, natural resource management, human health, community resilience, and economic activities. The Task Force also describes strategies necessary for building broad capacity to tackle climate risks at all levels. Throughout the report, the Task Force identifies specific federal programs and policies that could be improved to help reduce local climate risk, with an eye towards ensuring wise use of public resources in the face of changing conditions. 

Addressing perceptions of climate change risk and vulnerability in adaptation planning

McNeeley, S.M. & H. Lazrus.  2014.  The Cultural Theory of Risk for Climate Change Adaptation.  Weather, Climate and Society: 6, 506-519.  DOI: 10.1175/WCAS-D-13-00027.1  http://journals.ametsoc.org/doi/pdf/10.1175/WCAS-D-13-00027.1

The authors analyzed cultural worldviews using insights from community-based climate research and the Cultural Theory of Risk to characterize community understandings of, and responses to, climate change impacts. Their study examined how the issue of climate change is treated in four cases in the United States and Tuvalu and how ideas about climate change are produced by cultural institutions from local to global scales. They used this approach to identify local and regional priorities and to support adaptation research and planning by helping diagnose barriers. They also used their results to improve communication by framing/reframing climate issues to align with shared understandings and collective learning. Insights into diverse worldviews will help minimize conflict in favor of cooperation on issues relating to climate change.

Report recommends actions for future of sustainable and resilient U.S. freshwater resources

Over six years, The Johnson Foundation convened more than 600 experts representing diverse sectors and perspectives for intensive, solution-oriented work on U.S. freshwater issues. The culmination of that work is "Navigating to New Shores: Seizing the Future for Sustainable and Resilient U.S. Freshwater Resources," a report intended to provide a platform for leaders as they address water resource and infrastructure challenges. Without significant changes, existing water systems will soon no longer be able to provide the services that citizens expect. Recent water crises have illustrated that the economic and social consequences of inaction are far too great. This report illustrates what The Johnson Foundation believes is both possible and necessary to achieve if the U.S. is to successfully navigate its water challenges. 

Tribal and Indigenous Peoples Matters

Lummi mitigation bank receives 2014 Honoring Nations Award by the Harvard Project on American Indian Economic Development

The Lummi mitigation bank consists of 1,965 acres on three separate sites in the Lummi and Nooksack River floodplains. As a mitigation banker, the Lummi Nation restores, enhances, creates and preserves wetlands and endangered species habitat on these acres and, in return, is awarded “credits” by regulatory agencies. The Lummi then sell or transfer the credits to individuals, governmental agencies, and private companies to compensate for unavoidable negative impacts to wetlands on or off the reservation.  Mitigation banking provides one way to provide for the land while meeting needs for tribal housing and commercial and municipal development and diversifying the economy of the tribe.