Pacific Ocean warming boosts U.S. Southwest fires while dampening eastern Australia blazes
A new study finds that a long-term warming pattern in the tropical Pacific has increased fire-prone conditions in the U.S. Southwest by about 22% and reduced them in eastern Australia by roughly 19% over 1984-2022.
Analyzing satellite observations of burned forest area from 1984 to 2022, scientists identified a persistent warming disparity between the western and eastern tropical Pacific. This imbalance reshapes global atmospheric circulation, influencing moisture and temperature far beyond the ocean. By focusing on vapor pressure deficit as a measure of dryness, the team showed that the Pacific trend intensified drying in the U.S. Southwest, contributing an extra 22% to fire-related burned area on top of anthropogenic warming.
In eastern Australia, the same oceanic pattern partially countered climate-change-driven drying, resulting in an estimated 19% reduction in burned forest compared with a warming-only scenario. The findings underscore that natural climate variability can either amplify or dampen human-induced fire risk, offering a potential lever for improving seasonal and long-term fire forecasts worldwide.
Why it matters
Understanding how oceanic climate patterns interact with global warming helps improve fire risk predictions for vulnerable regions.
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