Human-caused climate change increases wildfire by intensifying its principal driving factor - heat. The heat of climate change dries out vegetation and accelerates burning.
Analyses show that human-caused climate change has driven the increases in burned area in the forests of western North America.
Across the western U.S., the higher temperatures of human-caused climate change doubled burned area from 1984 to 2015, compared with what would have burned without climate change. The additional area burned, 4.9 million hectares, is greater than the land area of Switzerland.
Elsewhere, deforestation, fire suppression, agricultural burning, and short-term cycles like El Niño can exert a stronger influence than climate change. In Australia, much of the southeastern part of the continent has experienced extreme wildfire years, but analyses suggest that El Niño, a heat phenomenon that cycles up and down periodically, is more important than long-term climate change.
Many forests and grasslands naturally require fire for ecosystem health but excessive wildfire can kill people, destroy homes, and damage ecosystems.
