UW News

February 11, 2009

New state climate report indicates coming decades will be challenging

News and Information

The most detailed report ever on how climate change could affect Washington paints a stark picture, but it should help the state avoid being surprised by climate-related changes coming down the road.

The assessment, which provides information critical to planning for climate change in the next 50 years, is built on global scenarios, one of low greenhouse-gas emissions and the other of medium emissions. The global scenarios were then tailored to reveal climate changes and consequences for Washington, something few other states have accomplished for themselves, says Edward Miles, University of Washington professor of marine affairs and head of the UW Climate Impacts Group.

The assessment will be released Wednesday, Feb. 11, to the state’s Department of Ecology and the Department of Community, Trade and Economic Development. The public can find the executive summary and final draft of the full report later this week at the Climate Impacts Group’s Web site, http://cses.washington.edu/cig/.

The 2007 state Legislature funded the Climate Impacts Group to lead the study, with Miles and UW civil and environmental engineering’s Dennis Lettenmaier as co-principal investigators. For the first time the group and its partners considered the effects of climate change on:


  • Human health where, under medium warming scenarios, more people are projected to die because of heat waves. In King County, for example, it is projected that by 2025 there could be 101 additional deaths among people 45 and older; by 2045, there could be an additional 156 deaths. Poorer air quality in the summers will also contribute to more deaths by mid-century.
  • Agriculture, where impacts on Eastern Washington are not projected to be severe for the winter wheat, apples and potatoes through mid-century, assuming there is the same amount of water for irrigation and that more carbon dioxide in the atmosphere, which plants use to grow, will prove beneficial. Yields of winter wheat, for instance, could increase about 8 percent during the 2020s and 20 percent during the 2040s. The effects of declining irrigation water supplies on crops were considered for the Yakima Valley, where there will be less water for all users, especially those with junior water rights, Miles says. Under the medium greenhouse-gas emission scenario, average apple and cherry yields could decline 20 to 25 percent in the 2020s. That would cause the value of apple and cherry production to decline by some $20 million, or 5 percent, in the 2020s. The effects, particularly on junior-water-right holders, could be even more pronounced after that, the report says.
  • Energy supply and demand, where the energy demand for cooling in the summer is expected to increase 400 percent by 2040 compared to the average demand for 1971-1999. The growth in demand will coincide with expected decreases in summertime flows in the Columbia River, which could mean 13 to 16 percent less power being produced in summers by the 2040s. Demand for winter heating is expected to grow until 2040 when warmer winters will slacken demand.
  • Existing urban storm sewers and systems, where results suggest that the magnitude of extreme high precipitation events will increase for the Puget Sound region.


These new areas of consideration were in addition to areas that have been studied by the Climate Impacts Group for more than a decade. Included in the new assessment are the latest findings about the effects of climate change on snowpack, streamflow and water storage, as well as on salmon, forests and coastal areas.

Partners in the study are Washington State University and the Pacific Northwest National Laboratory.

“I hope government and agencies take this very seriously and use the time available to begin planning in detail how they will respond and what they want citizens to do,” Miles says.

How society might slow the buildup of greenhouse gases is not part of the assessment. Such efforts, if successful, could mean the difference between dealing with the low greenhouse-gas emissions scenario in the report versus the intermediate scenario, or the difference between dealing with the intermediate scenario and even greater warming, the effects of which are not included in this assessment, Miles says.


The Washington Climate Change Impacts Assessment addresses the impacts of global climate change in the Pacific Northwest over the next 50 or more years on eight sectors: Hydrology and Water Resources, Energy, Agriculture, Salmon, Forests, Coasts, Infrastructure and Human Health. In addition, the assessment addresses the need for adaptive planning and adaptation options within each sector. Contact points for the assessment in general and individual sectors are provided below.


General Assessment Contacts
–Edward L. Miles (general assessment findings/co-principal investigator)
Director, Climate Impacts Group
Professor of Marine Studies and Public Affairs, UW School of Marine Affairs
edmiles@u.washington.edu, (206) 616-5348

–Dennis Lettenmaier, Professor (hydrologic impacts/co-principal investigator)
UW Dept. of Civil and Environmental Engineering
dennisl@u.washington.edu, (206) 543-2532

— Jeremy Littell, Research Scientist (forest impacts/day-to-day management of assessment)
UW Climate Impacts Group
jlittell@u.washington.edu, (206) 819-0876 (cell)

— Marketa McGuire Elsner, Research Scientist (hydrologic impacts/day-to-day management of assessment)
UW Climate Impacts Group
mmcguire@u.washington.edu, (206) 616-4304


Scenarios (temperature, precipitation, sea level rise)
— Philip Mote
Research Scientist, Climate Impacts Group
Washington State Climatologist
philip@atmos.washington.edu, (206) 616-5346

— Eric Salathé
Research Scientist, UW Climate Impacts Group
Affiliate Assist. Professor, UW Dept. of Atmospheric Sciences
salathe@atmos.washington.edu, (206) 616-5351


— Claudio Stöckle, Professor and Department Chair
WSU Biological Systems Engineering
stockle@wsu.edu, (509) 335-1578


– Daniel Huppert, Professor
UW School of Marine Affairs
Huppert@u.washington.edu, (206)543-0111


— Alan Hamlet, Research Assistant Professor
UW Department of Civil and Environmental Engineering
hamleaf@u.washington.edu, (206) 616-9361


— Jeremy Littell, Research Scientist (changes in fire risk, species, productivity/overall assessment results)
UW Climate Impacts Group
jlittell@u.washington.edu, (206) 819-0876 (cell)

— Don McKenzie (changes in fire risk, mountain pine beetle, forest species composition)
Research Ecologist, U.S. Forest Service
dmck@u.washington.edu, (206) 732-7824

— Elaine Oneil, Research Scientist (mountain pine beetle)
UW College of Forest Resources
eoneil@u.washington.edu, (206) 543-0827


Human health
— Michael G Yost, Professor and Director, Exposure Sciences Program (heat impacts)
Dept. of Environmental & Occupational Health Sciences
UW School of Public Health
airion@u.washington.edu,  (206) 685-7243, (206) 685-3250


— Catherine Karr, Assistant Professor, Pediatrics (air quality impacts)
UW School of Medicine
ckarr@u.washington.edu, (206) 744–9377


Hydrology and water resources
— Marketa McGuire, Research Scientist (overall hydrologic changes/general assessment findings)
UW Climate Impacts Group
mmcguire@u.washington.edu, (206) 616-4304

— Julie Vano, Graduate Student (Yakima/Puget Sound water analysis)
UW Dept. of Civil and Environmental Engineering
jvano@u.washington.edu, (608) 572-0087 (cell)


— Nathan Mantua
Research Scientist, Climate Impacts Group
Assoc. Research Professor, UW School of Aquatic and Fisheries Sciences
mantua@atmos.washington.edu, (206) 616-7041 (Fisheries office) (206) 616-5347 (CIG office)

(206) 713-4039




Urban stormwater infrastructure


— Derek Booth


Affiliate Professor, UW Dept. of Civil and Environmental Engineering


Consultant, Stillwater Sciences


dbooth@stillwatersci.com, (206) 914-5031



Eric Rosenberg, PhD Candidate


— UW Dept. of Civil and Environmental Engineering


ericrose@u.washington.edu, (917) 723-2143






— Lara Whitely Binder


Outreach Specialist


lwb123@u.washington.edu, (206) 616-5349