Climate Impacts on the Pacific Northwest

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Climate Impacts on the Pacific Northwest
The Science of Global Warming

• Eric Salathé
• Climate Impacts Group (JISAO/SMA)University of
  Washington

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The Climate Impacts Group

• Elements of the PNW we study
• Water resources
• Salmon
• Forests
• Coasts
• Goal make the region more resilient to climate
  variations and climate change

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Natures Greenhouse Effect
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Is Our Climate Changing? The Pacific Northwest

• 113 stations with long records
• Almost every station shows warming
• Urbanization not a major source of warming

100-year Temperature Trends
warming cooling
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1,000 Years of Climate Change
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150 Years of Climate Change
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Humans are altering the atmosphere

• carbon dioxide concentration has increased by
  30 since 1750s

• from a very long term perspective, these changes
  are enormous

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Whodunit?
Human Climate Influence
Natural Climate Influence
All Climate Influences
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Will Warming Continue?
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Future Climate Change

• Climate is changing, and humans are at least
  partly responsible.
• Earths average temperature will probably
  increase by 1.8-6.3F (1-3.5C) in the next 100
  years.
• Other climate changes are likely to accompany
  this warming (precipitation, storm tracks).
• These changes will have both positive and
  negative consequences.

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What Might Climate Change Look Like in the
Northwest?

• We looked at 7 scenarios of future climate from
  climate models
• Averages of 7 scenarios, compared to 20th
  century
• 2F warmer by 2020s
• 4F warmer by 2050s
• Slightly wetter
• Winters wetter
• Summers ???

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The Main Impact Less Snow
April 1 Columbia Basin Snow Extent
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Impacts of Hydrologic Changes

• Less snow, earlier melt means
• More water in winter
• Less water in summer
• Flooding
• Irrigation
• Salmon
• Hydropower
• Municipal water

Natural Columbia River flow at the Dalles, OR.
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Are We Prepared for a Changing Climate?

• Natural resource management presently assumes

Climate does not change
But what if it does?
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Becoming Climatewise

• Use climate information
• Requires on-going dialogue between
  decision-makers, climate scientists, and the
  general public
• Create centralized adaptable management
  strategies
• Learn from the past

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Becoming Climatewise Water, Salmon, Forests
and Coasts

• Water increase supply, decrease demand,
  increase management flexibility
• Salmon promote biodiversity by increasing
  healthy and connected habitat
• Forests maintain a full range of biodiversity
• Coasts recognize role of climate variability
  and change in coastal issues (erosion flooding)

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Conclusions

• Climate change likely to significantly affect the
  pacific northwest
• Main impact reduction in snowcap, summer
  streamflow
• Will exacerbate existing stresses in many cases
• Need to retool institutions and government
  agencies to respond to climate information and to
  plan for a changed climate
• Consider climate a component of any long-term plan