Source: Climate Change Impacts in the Pacific Northwest
Abstract:
1.5°F increase in Pacific Northwest average annual temperature during the 20th century, which has decreased the April 1st snowpack as much as 30-60% at some stations (1950-2000). Almost all PNW glaciers have retreated over the last 50-150 years. These changes can partially be attributed to natural variability, but not exclusively. A climate change trend is appearing regionally.
Projections for annual temperature change in the PNW range from 1.1-3.4°F by 2030, which will cause lower spring snowpack. Risk of drought increases, 3.6°F warming = 50-year droughts become 10-year droughts. Increased risk of winter flooding and decreased spring flooding. Sea level rise on Washington coast will range from 3″-21″ (6″ likely) by 2050.
Impacts:
- 34% of Portland water supply growth needs by 2040 are attributed to climate change
- Increased competition for water
- Increased vulnerability to flooding
- Coastal flooding due to sea level rise
- Shortened winter ski season
- More forest fires in summer
- Decreased air quality
- Hydropower – increased winter streamflow benefit winter hydro production
- Agriculture – decreased irrigation supply, increased heat stress/insects, increased growing season
- Infrastructure – intense winter precipitation will increase stormwater management costs
- Forests – increased wildfires (eastside especially), pine beetle poses risk in WA pine trees, Douglas-fir productivity decreases
- Energy – More heating degree days increases demand on power grid
