Download Impacts of Climate Change on the Northwest

The Science of Global Warming:
Climate Impacts on the
Pacific Northwest
Eric Salathé
Climate Impacts Group (JISAO/SMA)
University of Washington
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
Nature’s “Greenhouse Effect”
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
1,000 Years of Climate Change
150 Years of Climate Change
Humans are altering the atmosphere
 carbon dioxide
concentration has increased
by ~30% since 1750’s
 from a very long term
perspective, these changes
are enormous
Whodunit?
Natural Climate Influence
Human Climate Influence
All Climate Influences
Will Warming Continue?
Future Climate Change
Climate is changing, and humans are at least partly
responsible.
Earth’s average temperature will probably increase by
1.8-6.3°F (1-3.5°C) 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.
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 ???
The Main Impact: Less Snow
April 1
Columbia
Basin
Snow
Extent
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.
Are We Prepared for a Changing
Climate?
Natural resource management presently assumes
Climate does not change
But what if it does?
Becoming Climatewise
Use climate information
Requires on-going dialogue between decisionmakers, climate scientists, and the general
public
Create centralized & adaptable management
strategies
Learn from the past
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)
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