NW Climate Science Digest

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

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. 

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. 

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. 

Biodiversity/Species and Ecosystem Response

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.

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.

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.

Climate and Weather Reports and Services

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.

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.

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

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.

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.

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.

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.


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.

How Fire, Once a Friend of Forests, Became a Destroyer

In his new book Between Two Fires, Historian Stephen Pyne examines the roots of the U.S. wildfire crisis. He finds that while the Forest Service and other agencies have long recognized that frequent, relatively small fires can reduce the risk of large, catastrophic burns, they have been unable to restore a natural cycle of fire to the forest. National Geographic interviews Pyne in light of his new book. The interview discusses a range of topics such as historical U.S. forest policy analysis, the individuals and organizations who played major roles in progressing forest management, as well as Pyne’s view of how to achieve a safer and more ecologically sound future with forest fire.

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.

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.


Tree mortality from drought, insects, and their interactions in a changing climate

Anderegg, W.R., Hicke, J.A., Fisher, R.A., Allen, C.D., Aukema, J., Bentz, B., Hood, S., Lichstein, J.W., Macalady, A.K., McDowell, N. and Pan, Y., 2015. Tree mortality from drought, insects, and their interactions in a changing climate. New Phytologist, 208(3), pp.674-683.

Drought, heat stress, and insect attacks are all agents of tree mortality that are projected to increase with climate change. Yet, climate-induced tree mortality and the factors causing disturbance are largely absent from process-based ecosystem models. Using data sets from the western U.S. and associated studies, Anderegg et al (2015) present a framework for determining the relative contribution of drought stress, insect attack, and their interactions, which is critical for modeling mortality in future climates. The study outlines an approach that identifies the mechanisms associated with two guilds of insects – bark beetles and defoliators – which are responsible for substantial tree mortality. They then discuss cross-biome patterns of insect-driven tree mortality and draw upon available evidence contrasting the prevalence of insect outbreaks in temperate and tropical regions. The study concludes that a multitrophic approach that captures tree physiology, insect populations, and tree–insect interactions will better inform projections of forest ecosystem responses to climate change.

Carbon Balance and Forest Disturbance in the West Cascades

Turner, D.P., Ritts, W.D., Kennedy, R.E., Gray, A.N. and Yang, Z. 2015. Effects of harvest, fire, and pest/pathogen disturbances on the West Cascades ecoregion carbon balance. Carbon Balance and Management, 10(1), p.12.

A new study from Oregon State University examines carbon cycle impacts of harvesting, fire, and pest/pathogen disturbances on forests of the Western Cascades. Using a time series of Landsat remote sensing images and a climate-driven carbon cycle process model, the group quantified carbon flux attribution at the regional scale. The study found that 13% of total forest area in the Western Cascades ecoregion was disturbed during the reference interval (1991-2010). The authors found that harvesting was the main disturbance factor (59% of all area disturbed), and fire and pest/pathogen mortality had smaller effects (23% and 18%). Quantifying whether the Net Ecosystem Production (NEP) was positive or negative denoted either a carbon sink or carbon source. The study finds a positive NEP in all years, with greater carbon uptake in relatively cool years. Areas with recent harvests and fire were associated with negative NEP. The study concludes that the Western Cascades has maintained a positive carbon balance in recent decades, despite recurrent disturbance. The simulations used by this study display a high degree of temporal and spatial resolution, refining our understanding of regional carbon sources and sinks.

Land Use

Maps of Landforms and Physiographic Diversity for Climate Adaptation Planning

Theobald DM, Harrison-Atlas D, Monahan WB, Albano CM (2015) Ecologically-Relevant Maps of Landforms and Physiographic Diversity for Climate Adaptation Planning. PLoS ONE 10(12): e0143619. doi:10.1371/journal.pone.0143619

A recently published study creates a new high-resolution map of landforms for the conterminous United States to be used as a tool for current climate change adaptation strategies. By combining landforms and lithology at multiple spatial scales, Theobald et al (2015) developed new databases for 15 landforms and 269 physical geographic classifications. The group applied the new map to a current adaptation framework and reviewed its usefulness as a strategy tool. The authors found that the databases could play key roles in four of seven general adaptation strategies, and illustrate its use to inform current climate change adaptation efforts. The study concludes that this analytical framework of landform and lithology classification can be extended to other geographic areas and used as a supportive tool for climate change adaptation beyond the conterminous United States.

Special Reports / Announcements

Nisqually Refuge to be renamed for activist Billy Frank Jr.

The U.S. Congress has approved new legislation honoring Billy Frank Jr., a major civil rights activist from the Nisqually Reservation. The bill will rename the Nisqually Refuge the Billy Frank Jr. National Nisqually Wildlife Refuge. Also supported in the bill is a new memorial commemorating the Medicine Creek Treaty of 1854, a treaty concerning fishing rights to Indian tribes that Frank fought to enforce. Named the Billy Frank Jr. Tell Your Story Act, the legislation was unanimously supported by the state’s congressional delegation and backed by the National Congress of American Indians, the Affiliated Tribes of the Northwest Indians and the Northwest Indian Fisheries Commission. 

Statewide salmon projects get $44M

An announcement from the Washington Salmon Recovery Funding Board and Puget Sound Partnership offers funding to 141 habitat restoration projects around the state. Totaling $44.3 million, the restoration projects support salmon migration, from removing existing barriers to rebuilding safer habitat. While the Washington Salmon Recovery Funding Board reviewed projects, local tribes, governments, nonprofits, and citizen groups led the selection process. The projects are projected to boost economic activity in the state. More information can be found at www.rco.wa.gov.

Taking Action

Cities leading the world on climate action

The annual C40 awards were held on December 3rd, 2015, and cities around the world were honored for their efforts in fighting climate change. Included in the final 33 cities was Portland, Oregon, which was recognized for its 2015 Climate Action Plan. Because cities contain a massive percentage of the world’s population, climate action at the city scale can have a major impact on global climate change. Additionally, cities can be influential testing grounds for potential policies and technologies. For example, many of Portland’s renewable energy projects have been applied to other cities like Johannesburg, Kansas City, and Cincinnati. While dozens of cities were recognized at the 2015 C40 awards, four were selected as the global leaders on climate action: Cape Town, South Africa; Vancouver, British Columbia; Washington D.C., U.S.A.; and Stockholm, Sweden.

Paris climate deal: key points at a glance

This article from the guardian explains the key details from the Paris climate deal. Governments walked away from the Paris climate deal agreeing to limit global warming to 1.5C above pre-industrial levels. All countries have agreed to attain net zero emissions between 2050 and 2100. Of those countries, 187 have put forth plans for how to accomplish this. The deal also contains a mechanism that reviews countries’ progresses and makes a “global stocktake” every five years. Another key point in the deal is a mechanism for addressing financial losses that vulnerable countries face due to climate change, as well as funding to help developing countries adapt and transition to clean energy.

Tribal and Indigenous Peoples Matters

Salvage logging on burned Colville Indian Reservation

A recent article from The Seattle Times describes one of the largest ever logging operations in Washington State that is underway after massive fires on the Colville Indian Reservation destroyed much of their timber. Last year’s fires burned more than 250,000 acres of the Confederated Tribes of the Colville Indian Reservation land, and this logging plan is an effort to salvage as much board feet from the burned area as possible. It’s estimated that the tribe lost 802 million board feet that would have been worth $93 million. Though ecologically controversial, salvage logging is the only choice the reservation has of regaining any of that which was lost. By next summer, the tribe hopes to salvage 102 million board feet. Economically, this is a race against time, as winter weather will eventually halt operations. Beyond the tribe’s economic damage, the burned area has greatly affected the flora and fauna of the reservation as well. With much of the territory destroyed, animals are crowding what green habitat is left. This is causing abnormal wildlife behavior and has led the tribe to close its lands to subsistence hunting in an effort to help restore animal populations.