Climate Impacts on Climate Impacts on the the Pacific NorthwestPacific Northwest

Eric Salathé

Climate Impacts Group (JISAO/SMA)University of Washington

The Science of Global Warming:The Science of Global Warming:

Elements of the PNW we study: Water resources Salmon Forests Coasts

Goal: make the region more resilient to climate variations and climate change

The Climate Impacts GroupThe Climate Impacts Group

Nature’s “Greenhouse EffectNature’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

warming cooling

100-year Temperature Trends

1,000 Years of Climate Change

150 Years of Climate Change

carbon dioxide concentration has increased by ~30% since 1750’s

from a very long term perspective, these changes are enormous

Humans are altering the atmosphere

Natural Climate Influence Human Climate Influence

All Climate Influences

Whodunit?

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 changeClimate does not change

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

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)

ConclusionsConclusions

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