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FLASH - Final Upper Willamette River Basin Report identifies climate change stressors and risks, and offers preparation recommendations!
What Does a Climate-Changed Future Hold in Store for the Upper Willamette River Basin?
The National Center for Conservation Science & Policy and the University of Oregon's Climate Leadership Initiative, in partnership
with the US Forest Service Pacific Northwest Research Station MAPSS Team, downscaled global climate forecasts to determine the likely consequences in the Upper Willamette River Basin of western Oregon.
If global emissions continue on their current trajectory, projections for the Upper Willamette River Basin documented in the recently released report, Preparing for Climate Change in the Upper Willamette River Basin of Western Oregon, indicate significant climatic changes are likely (figures showing the complete set of model results for the Upper Willamette River Basin can be found in Appendix B of the report).
Temperature
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Annual average temperatures will increase from 2 to 4° F by around 2040 and by 6 to 8° F by around 2080
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Summer temperatures may increase dramatically, averaging 8 to 13° F warmer by 2080
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Winter temperatures may average 3 to 6° by 2080
Precipitation and Snowpack
- Total precipitation may remain roughly similar to historical levels
- Increasingly likely to fall in mid-winter months rather than in spring, summer and fall
- Snowpack across the Pacific Northwest is likely to decline by 60% by 2040 and 80-90% by 2095
- As snow melts earlier in the spring, stream flows will peak earlier
Disturbance
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With warmer oceans and more available moisture in the atmosphere, storm events could increase in intensity, resulting in more flooding in all rivers in the basin
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Increased wildfire may occur, but there is likely to be little change from historic conditions
Vegetation Patterns
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Temperature increases and changes in precipitation patterns likely will lead to changes in growing conditions, but plant and wildlife communities may take decades or centuries to adjust
- Fire is expected to be a major agent of vegetation change, even if fire incidence and size remain at approximately current levels
- In the western portion of the basin, future conditions are likely to become more suitable for mixed pine, hardwoods, and oaks.
- In the eastern portion of the basin, future growing conditions likely will be most suitable for ponderosa pine and Douglas-fir
The report assesses the risks posed to natural (ecosystems and species), built (buildings, roads, energy and water systems, and other infrastructure), human (public health, emergency management, social services), and economic systems in the basin by these climate changes.
It also offers recommendations on how to build resistance and resilience in all four sectors so they are better able to withstand and recover from the effects of climate change.
This project was undertaken to help pave the way for collaborative efforts, like those conducted through the Lane Council of Governments, to plan the necessary next steps that must be taken as local communities learn to cope with the effects of climate change.
Global Context
During the past 100 years, global annual average temperatures already have risen more than 1° Fahrenheit. Warming has been slightly more rapid in the Pacific northwest where annual temperatures now average 1.5° warmer than only a century ago.
According to the Intergovernmental Panel on Climate Change, it will take 50-100 years for the climate to stabilize due to the residence time of emissions already in the atmosphere.
photo credit: City of Eugene, OR
