Feb 15, 2024 - Climate

How climate change will impact Oregon's air quality

Estimated days with unhealthy air quality, 2024
Data: First Street Foundation; Note: Maximum count of days with unhealthy air quality from anywhere within each county; Map: Axios Visuals

Air quality in Oregon, and across the Pacific Northwest, is poised to worsen over the next three decades due to an increase in prolonged wildfire seasons and persistent drought, a new report suggests.

Why it matters: Research published by First Street Foundation, which provides climate-risk data, shows that even after decades of progress in the U.S. toward cleaner air, climate change-related events will cause a steady deterioration through 2054 — yielding a growing "climate penalty" to air quality.

  • The effects of this penalty are not evenly distributed around the country, however.
  • West Coast states, particularly Washington, Oregon and California, are projected to see some of the worst air quality impacts, chiefly from wildfire smoke.

What they found: The report from the nonprofit is part of a hyperlocal air quality model showing shifts down to the property level between 2024 and 2054.

  • Its conclusions flow from methods contained in three peer-reviewed studies published by the coauthors. The report itself is not peer-reviewed, however.
  • The study finds that climate change is increasing the prevalence of two of the air pollutants most harmful to human health: particulate matter, also known as PM2.5, and tropospheric ozone.
  • PM2.5 are tiny particles emitted by vehicles, power plants, wildfires and other sources. They can get lodged in people's lungs and enter the bloodstream, causing or exacerbating numerous health problems.

Zoom in: Through the use of air quality observations and the development of the new model, First Street's researchers found that the West will be particularly hard hit by increasing amounts of PM2.5 emissions, as wildfires become more frequent and severe.

  • EPA data shows that in the West more broadly, orange air quality days — where the air quality index level is above 100 — exploded by as much as 477% between 2000 and 2021, the report states.
  • Future projections estimate a continued increase in PM2.5 levels by nearly 10% over the next 30 years, Jeremy Porter, head of climate implications at First Street, told Axios.
  • This would "completely" erase air quality gains made in the last two decades, he said.

By the numbers: Multnomah County is predicted to experience 16 days annually where the air quality index (AQI) is above 100 by 2054. For 2024, the average is expected to be 12 days.

  • Counties in eastern and southern Oregon will see the largest increase in unhealthy air quality days.
  • Curry County, where the Rogue River-Siskiyou National Forest is located, is estimated to see a 15% increase in poor air quality days by 2054.
  • Clackamas County will also see a sizable jump, too — from 24 days in 2024 to 32 in 2054, a 33% increase.

What's next: Porter said the new air quality model's findings have been translated into risk levels, known as "Air Factor," for individual properties in the U.S.

  • The ratings will be available on large real estate listing sites.

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