The Pacific Northwest Climate CIGnal
The Climate Impacts Group (CIG) issues a quarterly electronic newsletter designed to provide updates on regional climate and climate-related research, meetings, and topics of interest to Pacific Northwest (PNW) decision makers and resource managers. The first newsletter was distributed in January 2005.
To subscribe to the newsletter, please visit the CIG's "climateupdate" list serve home page. You can also subscribe to the newsletter by sending a blank email to the following address: email@example.com.
The Pacific Northwest Climate CIGnal
Issue #14, Summer 2008
In this Issue
- Pacific Northwest climate outlook
- Pacific Northwest streamflow forecast updates
- Updated climate change scenarios available for the PNW
- Second U.S. National Assessment of climate change released
- Recent U.S. climate change Synthesis and Assessment reports
- CIG climate and water forecast meetings and other meetings of interest
- CIG in the news: Recent media stories
- Recent CIG publications
Temperatures have returned to normal and well-above normal throughout the Pacific Northwest after a cool spring, although coastal ocean temperatures continue to be exceptionally cold. Last winter's La Niña has moderated to ENSO-neutral, and most models currently project a continuation of ENSO-neutral conditions through at least February 2009. Read more...
West-wide Seasonal Hydrologic Forecasts Update (Columbia R., Snake R., and other western-U.S. rivers)
Hydrological conditions from April to June in the PNW region were influenced by below normal temperature and rainfall. These conditions produced below normal streamflows through mid-June at some stations along the upper and mid parts of the Columbia and Snake rivers, while the rest of the Columbia River basin was characterized by normal or above normal streamflows.
During the second part of June, the number of stations along the Columbia River with above normal streamflows doubled as temperatures warmed. Streamflows were also boosted by improved soil moisture conditions, which improved in late June as increasing snow melt and rainfall produced more soil moisture. By late June, streamflow was above normal at more than 80% of the stations in the PNW.
Streamflow projections for July 2008 through January 2009, when based on mid-July initial conditions, show below normal streamflows in the middle and lower reaches of the Snake River (OR-ID borders and WA-ID-OR borders) and most of the mainstem Columbia up to the U.S.-Canada border. A few stations in the upper portions of the Snake River are projected to have above normal streamflow (ID and WY), as well as some stations in the lowermost part of the Columbia river and the Canadian portion of the Columbia Basin.
Graphical depictions of recent estimates of soil moisture, snow water equivalent, and streamflow can be found at the University of Washington's West-wide Seasonal Hydrologic Forecast System web site. These experimental real-time forecasts are updated monthly and are based on several climate forecast methods. A number of products at the web-site are also updated on a daily basis. These include basin-averaged water balance conditions for each forecast point, spatial maps of current conditions, and a spatial summary of snow water equivalent for the western U.S.
A related effort that offers daily updates of hydrologic conditions throughout the U.S., can be found on the UW Experimental Surface Water Monitor web site. The Surface Water Monitor shows daily updating estimates of hydrologic conditions throughout the U.S. The site also offers weekly projections for soil moisture and runoff across the U.S. for lead times up to 3 months.
The Climate Impacts Group recently released updated (2008) climate change scenarios for the Pacific Northwest (PNW). As with previous assessments of PNW climate change, all scenarios evaluated by the CIG project a warmer PNW climate in the 21st century. Average annual temperature is projected to increase 2.2ºF (1.2ºC) by the decade of the 2020s, 3.5ºF (2.0ºC) by the decade of the 2040s, and 5.9ºF (3.3ºC) by the decade of the 2080s, relative to 1970-1999 average temperature. Temperatures are projected to increase across all seasons with most models projecting the largest temperature increases in summer (June-August).
Changes in precipitation are both less pronounced and less certain. The projected change in average annual precipitation is near zero, although individual model simulations produce annual changes as much as -10% or +20% by the 2080s. Seasonally, winter (Dec-Feb) precipitation is likely to increase and summer (Jun-Aug) precipitation is likely to decrease, although individual model results vary widely. Regardless of the change in winter precipitation, a larger percentage of overall winter precipitation is expected to fall as rain rather than snow due to warmer winter temperatures.
The 2008 PNW climate change scenarios show slightly larger annual temperature increases in all three periods (2020s, 2040s, and 2080s) than the 2005 scenarios. For precipitation, the average annual change is about the same but the range of possible precipitation changes is greater in all of the periods analyzed. These differences in temperature and precipitation are largely due to:
The consideration of more models and different emissions scenarios. The CIG's 2005 climate change projections were derived using 10 global climate models forced by two greenhouse gas and sulfate aerosol emission scenarios: the B1 and A2 scenarios. The 2008 climate change scenarios are derived from an evaluation of 20 global climate models driven by the B1 and A1B emissions scenarios.
Use of Reliability Ensemble Averaging. As part of the 2008 climate change scenarios update, the CIG used Reliability Ensemble Averaging (REA) to evaluate the climate change simulations. REA weights regionally-downscaled GCM simulations in accordance with each model's ability to replicate 20th century PNW climate.
More information on the CIG's 2008 scenarios is available here and in Mote et al. 2008. Annual and monthly summary data is also available for more detailed information on individual model/scenario performance.
In May 2008, the National Science and Technology Council (NSTC) and the U.S. Climate Change Science Program (CCSP) released the second U.S. national assessment of climate change. Scientific Assessment of the Effects of Global Change on the United States analyzes current trends in global change and provides an updated assessment of how climate change may affect agriculture, water resources, social systems, energy production and use, transportation, and human health. The report draws heavily from the findings of the CCSP's Synthesis and Assessment Products (SAPs) and the Intergovernmental Panel on Climate Change's fourth assessment of global climate change to provide a national overview of climate impacts. See below for more information on the SAPs.
A series of new national climate change reports known as the Synthesis and Assessment Products (SAPs) are currently being released by the Climate Change Science Program (CCSP). The SAPs draw from existing scientific literature to examine the impacts of climate change to U.S. agriculture, land and water resources, biodiversity, social systems, human health, transportation, and other sectors. Researchers at the CIG have contributed to several of these publications. Recent SAP reports include the following.
SAP 3.3 - Weather and Climate Extremes in a Changing Climate: Regions of Focus: North America, Hawaii, Caribbean, and U.S. Pacific Islands (released June 19, 2008)
SAP 3.3 provides the first comprehensive analysis of observed and projected changes in weather and climate extremes in North America and U.S. territories. Among the major findings reported in SAP 3.3 are that droughts, heavy downpours, excessive heat, and intense hurricanes are likely to become more commonplace as humans continue to increase the atmospheric concentrations of heat-trapping greenhouse gases. General findings for the PNW are found throughout the document.
SAP 4.3 - The Effects of Climate Change on Agriculture, Land Resources, Water Resources, and Biodiversity in the United States (released May 27, 2008)
SAP 4.3 evaluates past and projected changes in U.S. water resources, agriculture, land resources, and biodiversity. The report, written by a team of 38 scientists and researchers, was prepared through a comprehensive review, analysis, and synthesis of more than 1,000 separate scientific publications and represents the most extensive examination of the impacts of climate change on important U.S. ecosystems undertaken to date. The authors found that climate change is already affecting U.S. water resources, agriculture, land resources, and biodiversity, and will continue to do so. CIG Principal Dennis Lettenmaier was lead author on the water resources chapter and contributing author for several other chapters of the report.
SAP 4.4 - Preliminary Review of Adaptation Options for Climate-Sensitive Ecosystems and Resources (released June 24, 2008)
SAP 4.4 provides a preliminary review of adaptation options for the Nation's estuaries, forests, wetlands, coral reefs, and other sensitive ecosystems. The report's conclusions were drawn from examining federally-protected national parks, national forests, national wildlife refuges, wild and scenic rivers, national estuaries, and marine protected areas. The report finds, among other things, that climate change can increase the impact of traditional stressors (such as pollution or habitat destruction) on ecosystems, and that many existing best management practices to reduce these stressors can also reduce the impacts of climate change.
A case study on adaptation in the Olympic National Forest is featured in Chapter 3 (Case Study Summary 3.2) and Appendix A1.2. General findings for ecosystems in the PNW are also discussed to varying levels in other chapters. Contributing authors from the CIG for SAP 4.4 included Don McKenzie, Jeremy Littell, Dennis Lettenmaier, and David L. Peterson.
SAP 4.6 - Analyses of the Effects of Global Change on Human Health and Welfare and Human Systems (released July 17, 2008)
SAP 4.6 assesses the potential impacts of climate change on human health, human welfare, and communities in the U.S., identifies adaptation strategies for responding to the health-related impacts of climate change, and identifies near- and long-term research goals for addressing data and knowledge gaps. The report, released by the U.S. Environmental Protection Agency, is considered the most up-to-date synthesis and assessment of scientific literature on the impact of global change on human health in the U.S.
Mark your calendars! The CIG's annual climate and water fall forecast meetings for the 2009 Water Year have been scheduled. The Washington/Oregon fall forecast meeting will be held on Thursday, October 2, 2008 in Vancouver, Washington. The Idaho fall forecast meeting will be held on Thursday, October 16, 2008, in Boise, Idaho. Meeting web sites and draft agendas are forthcoming. Notice about meeting registration will be sent over the CIG's "climateupdate" list serve in the coming month. For information on last year's meetings, please visit the CIG's workshops page.
Other Meetings of Interest
2008 Oregon Watershed Enhancement Board (OWEB) conference, “Working for Healthy Watersheds-Climate Change and Watershed Resilience”, November 5-7, Eugene, Oregon.
OWEB's biennial conference will feature keynote speakers and numerous workshop sessions on the impacts of climate change for Oregon's watersheds. Other major workshop topics will include invasive species and restoration project management. The event will be held at the Eugene Hilton and Conference Center. Registration for the event will open in September. More information will soon be available on OWEB's Web site.
Recent media stories featuring CIG research and/or researchers include the following:
- June in Seattle more like Juneau, The Seattle Post-Intelligencer, June 11, 2008
- Cantwell, Inslee focus on increasing acidity of oceans at Seattle hearing , The Seattle Times, May 28, 2008
Additional news items are available at CIG in the News.
Recent CIG publications include the following:
- Climate Change Science Program. 2008. The Effects of Climate Change on Agriculture, Land Resources, Water Resources, and Biodiversity. A report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. P. Backlund, A. Janetos, D. Schimel, J. Hatfield, K. Boote, P. Fay, L. Hahn, C. Izaurralde, B.A. Kimball, T. Mader, J. Morgan, D. Ort, W. Polley, A. Thomson, D. Wolfe, M. Ryan, S. Archer, R. Birdsey, C. Dahm, L. Heath, J. Hicke, D. Hollinger, T. Huxman, G. Okin, R. Oren, J. Randerson, W. Schlesinger, D. Lettenmaier, D. Major, L. Poff, S. Running, L. Hansen, D. Inouye, B.P. Kelly, L Meyerson, B. Peterson, R. Shaw. U.S. Environmental Protection Agency, Washington, DC., USA, 362 pp.
Joyce, L.A., G.M. Blate, J.S. Littell, S.G. McNulty, C.I. Millar, S.C. Moser, and R.P. Neilson. 2008. National forests. Chapter 3 in S.H. Julius, J.M. West (eds.), J.S. Baron, B.Griffith, L.A. Joyce, P. Kareiva, B.D. Keller, M.A. Palmer, C.H. Peterson, and J.M. Scott (authors), Preliminary Review of Adaptation Options for Climate-Sensitive Ecosystems and Resources. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. U.S. Environmental Protection Agency, Washington, DC, USA, pp. 3-1 to 3-127.
- Palmer, M.A., D.P. Lettenmaier, N.L. Poff, S. Postel, B. Richter, and R. Warner. 2008. Wild and scenic rivers. Chapter 6 in S.H. Julius, J.M. West (eds.), J.S. Baron, B.Griffith, L.A. Joyce, P. Kareiva, B.D. Keller, M.A. Palmer, C.H. Peterson, and J.M. Scott (Authors), Preliminary Review of Adaptation Options for Climate-Sensitive Ecosystems and Resources. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. U.S. Environmental Protection Agency, Washington, DC, USA, pp. 6-1 to 6-73.
Posted August 1, 2008