NW Climate Science Digest

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

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.

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.

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.

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.

Arid Ecosystems

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.

Biodiversity/Species and Ecosystem Response

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.

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.

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.

Climate and Weather Reports and Services

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.

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:

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

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.

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.

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.

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.


Projected changes in fire and vegetation in the Pacific Northwest for selected climate futures

Sheehan T, Bachelet D, Ferschweiler K (2015) Projected major fire and vegetation changes in the Pacific Northwest of the conterminous United States under selected CMIP5 climate futures. Ecological Modelling 317: 16-29. doi: 10.1016/j.ecolmodel.2015.08.023

The Integrated Scenarios project, a collaboration between the Northwest Climate Science Center, the University of Idaho, Conservation Biology Institute and the University of Washington, modeled future changes in hydrology, climate and vegetation over the western United States, from the Pacific coast to the Great Plains. Results from CMIP5 models were evaluated for performance in terms of simulating the climate of the Northwest, and those that performed the best were downscaled to finer grids and then used in regional hydrologic and vegetation models. This study presents regional results for the Pacific Northwest for RCP 4.5 and 8.5 and uses MC2, a dynamic global vegetation model. Results were aggregated into three subregions: the Western Northwest (WNW) (from the crest of the Cascade Mountains west), Northwest Plains and Plateau (NWPP) (non-mountainous areas east of the Cascades) and Eastern Northeast Mountains (ENWM) (mountainous areas east of the Cascades). The authors find that the mean fire interval decreases by up to 48% in the WNW, and potential vegetation shifts from conifers to mixed forest for RCP 4.5 and 8.5. For the NWPP, the mean fire interval decreases by up to 82% and increases by up to 14% if fire suppression is used. In the ENWM, the mean fire interval decreases by up to 81% and subalpine communities are entirely lost.

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.  


Understanding forestry and climate impacts on streamflow

Burt TP, Howden NJK, McDonnell JJ, Jones JA, Hancock GR (2015) Seeing the climate through the trees: observing climate and forestry impacts on streamflow using a 60-year record. Hydrological Processes 29: 473-480. doi: 10.1002/hyp.10406

In this study, the authors used historical data from the H.J. Andrews Experimental Forest in Oregon to explore the relative impacts of El Nino Southern Oscillation climate variability and forest harvesting on streamflow. Historical data is taken from watershed experiments in which forest cover has been removed or altered in order to understand the impact of forestry operations on streamflow. By analyzing a 60-year record from the experimental forest, it was found that climatic variability is the dominant driver of streamflow (vis-à-vis changes in forest cover) due to the contrast between El Nino and La Nina years.

Land Use

Adapting transportation to climate change on federal lands in Washington State:

Strauch RL, Raymond CL, Rochefort RM, Hamlet AF, Lauver C (2015) Adapting transportation to climate change on federal lands in Washington State, U.S.A. Climatic Change 130: 185-199. doi: 10.1007/s10584-015-1357-7

A new study looks at climate change vulnerability in national parks and forests in Washington State. The researchers collaborated with federal land managers and conducted a vulnerability assessment and identified adaptation strategies for a network consisting of 28,900 km of roads and trails in north-central Washington. The study included a wide variety of data sources, including observations of sensitivity and response to climate variability, climate projections, literature reviews, expert knowledge, management policies and stakeholder engagement. The largest impact on roads and trails is expected to occur from enhanced fall flooding and decreases in spring snowpack.

Projecting climate change impacts on land use in the Willamette River Basin

Turner DP, Conklin DR, Bolte JP (2015. Projected climate change impacts on forest land cover and land use over the Willamette River Basin, Oregon, USA. Climatic Change. doi: 10.1007/s10584-015-1465-4

Climate change has significant impacts on forests, such as alteration of the disturbance regime, disruption of the carbon cycle, shifts in distribution of vegetation types, increases and decreases in forest productivity, and changes in species composition. These impacts have been studied, but tend not to include land use. In this study, the authors incorporated an agent-based landscape simulation model (Envision) with results from a dynamic global vegetation model (MC2). They used climate scenarios developed for the 5th IPCC report. Using an agent-based model allowed for the inclusion of decisions such as harvesting and probability of fire. They explored the sensitivity of forest area, biogeography, fire rates, harvest rates and forest age class distribution to three climate change scenarios in the Willamette River Basin. The authors found that the dominant vegetation type was projected to remain forest, but forest type would transition from primarily evergreen needleleaf to a mixture of broadleaf and needleleaf growth. In moderate to high climate change scenarios, the average area burned per year was projected to increase from three to nine fold from the present. Generally, a more disturbed and open forest landscape is projected to occur by the end of the 21st century.

Special Reports / Announcements

Pacific Northwest salamanders may qualify for protection:

The US Fish and Wildlife Service announced that two species of salamanders in Oregon and Washington may qualify for protection under the Endangered Species Act. The two species, the Cascade torrent salamander and the Columbia torrent salamander, will undergo full status reviews to see if they need protection. The Center for Biological Diversity first asked for protection of the salamander species in 2012, citing low numbers of the species due to habitat loss from logging and roads. The salamanders live in streams and are only found in the Cascades and Coast ranges.

NSF awards $12 million to establish urban water sustainability network

A consortium of 14 academic institutions in the US have received $12 million in total from the National Science Foundation to address challenges to urban water systems in the US and globally. The network will establish six connected regional urban water sustainability hubs across the US. The goal of the project is to create a research network for integrated water systems and foster innovation for water-sensitive urban design and building resilient cities. The consortium of 14 academic institutions includes two universities in the Pacific Northwest – University of Oregon and Oregon State University.

Taking Action

Obama administration unveils new climate resilience tools:

data resources to assist Arctic communities with climate change planning, adaptation and management. The new data sets were introduced as part of an online Climate Resilience Toolkit and contain more than 250 datasets and over 40 maps and other resources. In addition to climate data sets for the Arctic, Assistant Secretary of Indian Affairs Kevin Washburn and Secretary Jewell announced that the U.S. Climate Resilience Toolkit would be updated with climate impacts information that is particular to tribal nations. The tribal climate resources were developed with support by tribes, NOAA and the EPA and were supported by the White House Council on Native American Affairs.

Tribal and Indigenous Peoples Matters

Indian Country article on TEK Research

Indian Country Newsletter published an article reporting on a new study being conducted at Oregon State University documenting ‘Indian time’ as an interaction between climate and traditional ecological knowledge (TEK). To find out if Native people were changing traditional rituals and behaviors due to climate change, Samantha Chisholm Hatfield, a researcher at Oregon State, interviewed people from the Confederated Tribes of Siletz Indians in Oregon, the Quinault Indian Nation in Washington, the Duckwater Shoshone in Nevada and the Paiute in Utah.