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

The 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? From IPCC Working Group I Human Climate Influence Natural Climate Influence All Climate Influences From IPCC Working Group I

Will Warming Continue?

Future Climate Change Climate is changing, and humans are partly responsible. Average surface temperature will probably increase by 3 to 11°F (1.5-6.0°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.

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 As Ben Franklin put it… The question is, are we... But what if it does?

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 1. The single most important thing that the region can do to prepare for climate change is to use climate information in our planning and decision-making processes. -- increased awareness of how climate affects the region will enable decision makers to better manage the region’s natural resources as the climate changes -- as scientists learn how climate forecasts are used, they can make more useful forecasts and provide more useful information on climate change 2. Management needs to be flexible/agile enough to operate differently under different climate conditions. Much water res mgt based on strict rule curves that define how managers must operate and don’t allow them to adapt to conditions that may vary from year-to-year. Following flood prevention rule curves was one of the reasons SPU experienced water shortages in 1992. 3. Climate variations such as El Nino/La Nina and the PDO have been with us throughout this century. By examining how well we dealt with these climate variations in the past, we can prepare for the future. When the SPU learned how EN had impacted them in the past, they used that knowledge and forecasts of EN to help them better prepare for the future. *Applies to management of nat resources in general as the climate changes * Now address specific ways to adapt to projected impacts of climate change on water, salmon...

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 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.