1. Climate Impacts on the Pacific Northwest
The Science of Global Warming:
Climate Impacts on the Pacific Northwest
Eric Salathé
Climate Impacts Group (JISAO/SMA) University of Washington

2. The Greenhouse Effect”

3. 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

4. 150,000 years of Climate Change

5. 1,000 Years of Climate Change

6. Humans are altering the atmosphere
carbon dioxide concentration has increased by ~30% since 1750s
from a very long term perspective, these changes are enormous

7. Whodunit? From IPCC Working Group I Human Climate Influence
Natural Climate Influence
All Climate Influences
From IPCC Working Group I

9. Future Climate Change
Climate is changing, and humans are partly responsible.
Average surface temperature will probably increase by 3 to 11°F ( °C) by the year 2100.
Other climate changes are likely to accompany this warming (precipitation, storm tracks).
These changes will have both positive and negative consequences.

11. Impact: Less Snow
April 1
Columbia
Basin
Snow
Extent

12. Impact: Hydrologic Changes
Less snow, earlier melt means
More water in winter
Less water in summer
Flooding
Salmon
Hydropower
Irrigation
Municipal water
Natural Columbia River flow at the Dalles, OR.

13. Impact: Mountain Ecosystem
Species distributions
Ecosystem processes
productivity
hydrology
Disturbance
Fire
Pest
Wind

14. Impact: Human-nature interaction
Changes in agriculture and forestry as climate changes
Migration limited by land use
Impacts of climate change on natural systems depends largely on response of human systems

15. Forests
Model future vegetation changes including effects of changes in
temperature
precipitation
CO2 (uncertain)
fire
Vegetation Carbon Change by (Ron Neilson, OSU)
Significant spatial variation in projected changes.
Vegetation change models are a major source of uncertainty.
Results from Ron Neilson for HadCM2 scenario w/ MC1 veg model and assumed increase in WUE. For MC1, very little diff with/without enhanced WUE. Bigger diff b/t climate change scenarios. But biggest diff is between veg models.
MC1 is Middle of the road (among models we’ve examined): MAPPSS model is much browner overall (esp. w/ no increase in WUE) and BIOMEBGC is greener overall.

17. Conclusions Will exacerbate existing stresses in many cases
Need to retool institutions and government agencies to respond and plan for a changed climate
Climate change may be favorable or not, but depends on resonse of human systems
CC: As Phil described, we know from the past that subtle variations in climate can have profound impacts on the region, and the changes projected by the climate models are anything but subtle.
IMPACTS: are likely to be felt among the natural resources of the region -- the water res….
RETOOL: At present, the region is ill-prepared to tackle a changing climate, but some improvements are being made. …… climate change will also bring some benefits, but we will be most likely to reap those benefits if we are prepared for them.
LONG-TERM: Think about some long-range plans and decisions that are currently being made: habitat conservation plans, salmon recovery plans, plans to ensure future water supply for cities and towns, dam relicensing, land use planning near shore and bluffs and in potential flood areas, and planting of trees for commercial timber. CV’s and CC have an important bearing on each of these decisions. We know enough already to begin the process of changing how we think about climate in the context of natural resources decisions.
It’s time to start.