During the twentieth century the Pacific Northwest warmed by some 0.7 degrees Celsius (1.3 degrees Fahrenheit), according to CIRC research. That warming has continued in recent years and is expected to continue throughout this century. Our research indicates that by the year 2100 the Pacific Northwest is likely to be anywhere from 1 to 8 ° C (2–15 ° F) warmer than it was during the second half of the twentieth century. This warming is expected to have a series of cascading effects on our landscapes, producing impacts as varied as winter flooding, summer drought, raging wildfires, and rising sea levels. This section of our website is intended as a kind of primer, outlining what our research says about some of these impacts. The section is also intended to demystify how our climate and social science research is conducted. This is why, whenever possible, we describe both our results as well as the methods we used to arrive at those results.

Modeling & Analysis

To understand the Earth’s complex processes, researchers employ powerful computer models. At CIRC we are working to advance the state of the science in modeling and analysis through our work with global climate models, regional climate models, hydrologic models, and vegetation models. We also do this thing called downscaling. Don't worry, we'll explain what all that means.  

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Human Choice, Warming, & Emissions:

The Representative Concentration Pathways

More emissions of CO2 and other greenhouse gases spells more warming for our climate. That much is clear. What isn’t clear is how much more emissions, and thus warming, we can expect. Lucky for us, climate researchers have developed a kind of shorthand for this uncertainty: the Representative Concentration Pathways.

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Climate Impacts

Climate impacts are effects on human communities and natural systems that result from changes in the climate. Climate impacts can result from anthropogenic (or human-caused) climate change, such as the notable long-term increase in average annual air temperatures in recent decades, or from natural climate variability, such as flooding connected to periodic El Niño and La Niña events. Climate impacts and our findings around them are listed by impact.


By the year 2100, CIRC research indicates that the Pacific Northwest could be anywhere from 1 to 8 ° C (2–15 ° F) warmer than it was during the second half of the twentieth century.

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Precipitation projections for the Pacific Northwest don’t share the same level of confidence as temperature projections. We explain what that means, why annual precipitation might stay about the same or nudge slightly wetter, how our region’s summers might nudge slightly drier while our winters might nudge slightly wetter, and why all of this needs to be framed within pretty strict statistical wording.

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Snowpack, Hydrology, & Drought

Rising temperatures in the Pacific Northwest are changing our region’s hydrology, causing precipitation to fall more as rain and less as snow. This change has already led to water scarcities in the region. These scarcities are expected to continue in the future as our climate warms.

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Wildfires & Changing Vegetation

Rising temperatures are expected to make conditions ideal for larger, more destructive wildfires here in the Pacific Northwest. These fires, along with other disturbances, are expected to change the types of trees and other vegetation found in our region.

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Coastal Hazards & Extremes

A combined threat of rising sea levels, intensifying waves, and major El Niños has led to increased flooding and erosion hazards along the Pacific Northwest Coast. Learn the basics about hazards and extremes along our coast as our climate changes.

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Social Science

When CIRC researchers work with local communities to help them adapt to climate change, we are guided both by social science research and an innovative scientific philosophy. This section gets at the ethos underpinning how we deal with the “wicked problem” that is climate adaptation.

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