The Washington Climate Change Impacts Assessment Evaluating Washington’s Future in a Changing Climate ........................................................................................................ A report by The Climate Impacts Group University of Washington Climate Science June 2009 in the Public Interest Recommended citation: Climate Impacts Group, 2009. The Washington Climate Change Impacts Assessment, M. McGuire Elsner, J. Littell, and L Whitely Binder (eds). Center for Science in the Earth System, Joint Institute for the Study of the Atmosphere and Oceans, University of Washington, Seattle, Washington. Available at: http://www.cses.washington.edu/db/pdf/wacciareport681.pdf Front cover satellite image credit: http://visibleearth.nasa.gov/view_rec.php?vev1id=4786 NASA - National Aeronautics and Space Administration Visible Earth: A catalog of NASA images and animations of our home planet Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE The Pacific Northwest is cloud-free in this SeaWiFS image. Multihued phytoplankton blooms are visible off of Washington's Olympic coast. Also visible in this image are: Fraser River outflow, snowcapped peaks of Mt. Olympus, Mt. Rainier, Mt. Adams, Mt. Hood, Mt. Jefferson, the Three Sisters, the North Cascades, and the Columbia and Snake River watersheds. Metadata * Sensor OrbView-2/SeaWiFS * Visualization Date 2000-09-26 * The Visible Earth is part of the EOS Project Science Office located at NASA Goddard Space Flight Center. Small images credits: Wheat: © 2009 www.photos.com Coast; Seattle skyline: © J. Martin Grassley McNary Dam: courtesy Bonneville Power Administration Salmon: courtesy University of Washington News and Information Forest: courtesy Climate Impacts Group, University of Washington Report design: Beth Tully, Edit-Design Center, University of Washington The Washington Climate Change Impacts Assessment Evaluating Washington’s Future in a Changing Climate ......................................................................................... A report by The Climate Impacts Group University of Washington June 2009 Edited by: Marketa McGuire Elsner Jeremy Littell Lara Whitely Binder WACCIA Executive Summary iii PRINCIPAL INVESTIGATORS: Edward L. Miles, Director, Climate Impacts Group and Bloedel Professor of Marine Studies and Public Affairs, School of Marine Affairs, University of Washington Dennis P. Lettenmaier, Professor, Dept. of Civil and Environmental Engineering, University of Washington TEAM MEMBERS: Jeremy Avise, Atmospheric Modeling and Support Section, California Air Resources Board Derek B. Booth, Stillwater Sciences and Dept. of Civil and Environmental Engineering, University of Washington Rick Boydston, USDA-ARS, Washington State University IAREC Jay Brunner, Tree Fruit Research and Extension Center, Washington State University Jeff Burkey, King County Water and Land Resources Division Jack Chen, Institute for Chemical Process and Environmental Technology, National Research Council Canada Serena H. Chung, Laboratory for Atmospheric Research, Dept. of Civil and Environmental Engineering, Washington State University Lan Cuo, Dept. of Civil and Environmental Engineering, University of Washington Meriel Darzen, Kathy and Steve Berman Environmental Law Clinic, University of Washington Jeffrey S. Deems, Dept. of Civil and Environmental Engineering, University of Washington Karen Dyson, School of Marine Affairs, University of Washington Marketa McGuire Elsner, Climate Impacts Group, University of Washington Richard A. Fenske, Environmental & Occupational Health Sciences, University of Washington Cole Fitzpatrick, Environmental & Occupational Health Sciences, University of Washington Thomas F. Graham, Kathy and Steve Berman Environmental Law Clinic, University of Washington Gary Grove, Irrigated Agricultural Research and Extension Center, Washington State University Alan F. Hamlet, Climate Impacts Group and Dept. of Civil and Environmental Engineering, University of Washington David Hartley, Northwest Hydraulic Consultants Marc J. Hershman, School of Marine Affairs, University of Washington (in memoriam) Stewart Higgins, Dept. of Biological Systems Engineering, Washington State University Jeffrey A. Hicke, Dept. of Geography, University of Idaho John Hodges-Howell, Kathy and Steve Berman Environmental Law Clinic, University of Washington Daniel D. Huppert, School of Marine Affairs, University of Washington J. Elizabeth Jackson, Dept. of Family Medicine and Dept. of Sociology, University of Washington Catherine Karr, Dept. of Pediatrics and Environmental & Occupational Health Sciences, University of Washington Patrick W. Keys, Dept. of Civil and Environmental Engineering, University of Washington Jennifer Krencicki Barcelos, Kathy and Steve Berman Environmental Law Clinic, University of Washington Chad Kruger, Center for Sustaining Agriculture & Natural Resources, Washington State University Brian K. Lamb, Laboratory for Atmospheric Research, Dept. of Civil and Environmental Engineering, Washington State University Se-Yeun Lee, Dept. of Civil and Environmental Engineering, University of Washington Dennis P. Lettenmaier, Dept. of Civil and Environmental Engineering, University of Washington L. Ruby Leung, Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory Jeremy S. Littell, Climate Impacts Group, University of Washington James A. Lutz, College of Forest Resources, University of Washington Nathan Mantua, Climate Impacts Group and School of Aquatic and Fishery Sciences, University of Washington Jennifer Marlow, Kathy and Steve Berman Environmental Law Clinic, University of Washington Don McKenzie, Climate Impacts Group and USDA Forest Service Pacific Northwest Research Station Kristian E.B. Mickelson, Dept. of Civil and Environmental Engineering, University of Washington Edward L. Miles, Climate Impacts Group and School of Marine Affairs, University of Washington Amber Moore, School of Marine Affairs, University of Washington Philip W. Mote, Climate Impacts Group and Office of the Washington State Climatologist Roger L. Nelson, Dept. of Biological Systems Engineering, Washington State University Robert A. Norheim, Climate Impacts Group Elaine E. Oneil, Rural Technology Initiative, College of Forest Resources, University of Washington Richard N. Palmer, Dept. of Civil and Environmental Engineering, University of Massachusetts Amherst Austin Polebitski, Dept. of Civil and Environmental Engineering, University of Massachusetts Amherst Yun Qian, Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory Michael Robinson-Dorn, Kathy and Steve Berman Environmental Law Clinic, University of Washington Eric A. Rosenberg, Dept. of Civil and Environmental Engineering, University of Washington Roger A. Rosenblatt, Dept. of Family Medicine, University of Washington Eric P. Salathé, Jr., Climate Impacts Group, University of Washington Michael Scott, Pacific Northwest National Laboratory Amy K. Snover, Climate Impacts Group, University of Washington Anne C. Steinemann, Dept. of Civil and Environmental Engineering and Evans School of Public Affairs, University of Washington Claudio O. Stöckle, Dept. of Biological Systems Engineering, Washington State University Ingrid Tohver, Climate Impacts Group, University of Washington Julie A. Vano, Dept. of Civil and Environmental Engineering, University of Washington Nathalie Voisin, Dept. of Civil and Environmental Engineering, University of Washington Lara C. Whitely Binder, Climate Impacts Group, University of Washington Mathew Whiting, Irrigated Agricultural Research and Extension Center, Washington State University Michael G. Yost, Environmental & Occupational Health Sciences, University of Washington Yongxin Zhang, Climate Impacts Group, University of Washington iv WACCIA Executive Summary Table of Contents Executive Summary 1 Evaluating Washington’s Future in a Changing Climate 1: Scenarios 21 Future Climate in the Pacific Northwest 2: Regional Climate Models 45 Regional Climate Model Projections for the State of Washington 3: Hydrology and Water Resources Implications of 21st Century Climate Change 69 for the Hydrology of Washington State Climate Change Impacts on Water Management 107 in the Puget Sound Region, Washington State Climate Change Impacts on Water Management and Irrigated 132 Agriculture in the Yakima River Basin, Washington State 4: Energy 165 Effects of Projected Climate Change on Energy Supply and Demand in the Pacific Northwest and Washington State 5: Agriculture 191 Assessment of Climate Change Impact on Eastern Washington Agriculture 6: Salmon 217 Impacts of Climate Change on Key Aspects of Freshwater Salmon Habitat in Washington State 7: Forests 255 Forest Ecosystems, Disturbances, and Climatic Change in Washington State 8: Coasts 285 Impacts of Climate Change on the Coasts of Washington State 9: Stormwater Infrastructure 311 Precipitation Extremes and the Impacts of Climate Change on Stormwater Infrastructure in Washington State 10: Public Health Impacts 345 Public Health Impacts of Climate Change in Washington State: Projected Mortality Risks Due to Heat Events and Air Pollution 11: Preparing for Climate Change 373 Preparing for Climate Change in Washington State WACCIA Executive Summary v vi WACCIA Executive Summary Washington Climate Change Impacts Assessment Evaluating Washington’s Future in a Changing Climate Executive Summary emperature records indicate that Pacific Northwest Probable impacts associated