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Climate Change in Oregon
Climate Impacts in Oregon
crater lake
The impacts of climate change will not be the same around the world; therefore, regionally specific climate information is essential for the further creation of climate mitigation and adaptation policy. The key climate issues that Oregon is projected to face are increased temperatures, declining springtime snowpack leading to reduced summer streamflows, sea level rise along the coastline, and predicted increase in intense precipitation events. All of these have a great potential for impacting Oregon’s transportation system and infrastructure.
  • Models scaled to the Pacific Northwest project and increase in average temperature on the order of 0.2° – 1.0° F per decade throughout the mid-21st century, with a best estimate average of 0.5° F per decade.[1] 
  • There is still a lot of uncertainty around precipitation changes in the future.[2] 
  • According to one report, average annual change in precipitation in the Pacific Northwest is projected to increase by up to 10%. Summer precipitation will likely decrease, somewhere along the order of 5-15%, while winter precipitation will most likely increase by about 15-30%.[3]
Sea level rise:
  • Current estimates call for an increase of 56cm (about 1.8ft) of sea level rise by 2050 and 127cm (a little over 4ft) rise by 2100 in the Pacific Northwest.[4]
Streamflow and Snow cover:
  • Snow cover is projected to melt earlier, leading to higher spring flows and lower later summer flows.[5]
  • The decline of the region’s snowpack is predicted to be greatest at low and middle elevations due to increases in air temperature and less precipitation falling as snow. The average decline in snowpack in the Cascade Mountains, for example, was about 25% over the last 40 to 70 years.[6] 

[1] “Future Climate Change in the Pacific Northwest”, Climate Change Impacts Group (CIG) Joint Institute for the Study of the Atmosphere and Ocean at the University of Washington, March 2008. <http://cses.washington.edu/cig/pnwc/cc.shtml#anchor6>
[2] John Bragg, Adapting to Climate Change, Coastal & Estuarine Research Federation, June 2009. <http://www.erf.org/news/adapting-climate-change-third-series >
[3] Philip Mote and Salathé E., Future climate in the Pacific Northwest, Chapter 1 in the Washington Climate Change Impacts Assessment: Evaluating Washington’s Future in a Changing Climate (Seattle, Washington: University of Washington Climate Impacts Group, 2009). <http://cses.washington.edu/db/pdf/wacciaexcsummary638.pdf>
[4] John Bragg, Adapting to Climate Change, Coastal & Estuarine Research Federation, June 2009. <http://www.erf.org/news/adapting-climate-change-third-series >
[5] Summary of New IPCC Findings on Climate Change: Implications for Oregon and Washington, The Climate Change Leadership Initiative at University of Oregon, February 12, 2007.
[6] J.S. Littell, M. McGuire Elsner, L.C. Whitely Binder, and A.K. Snover (eds). 2009. The Washington Climate Change Impacts Assessment: Evaluating Washington’s Future in Changing Climate, Climate Impacts Group, University of Washington, Seattle, Washington. <http://www.cses.washington.edu/db/pdf/wacciaexecsummary638.pdf>

More Climate Information
For more detailed information on the impacts of climate change in Oregon and the Pacific Northwest, check out these links:
United States Global Research Program - Northwest  
Oregon Climate Change Research Institute (OCCRI) 
Oregon Climate Assessment Report - State of climate science in Oregon
Western Regional Climate Center's summary on the "Climate of Oregon"