Climate change is fueling California’s fires

Today’s Image of the Day from NASA Earth Observatory shows burn scars from the Dixie Fire, which burned nearly one million acres across forests in Northern California from July 13 to September 30, 2021.

According to the California Department of Forestry and Fire Protection (Cal Fire), eight of the state’s ten largest fires on record – and twelve of the top twenty – have happened within the past five years. 

“The current drought is unprecedented,” said Jon Keeley, a U.S. Geological Survey scientist based in Sequoia National Park. “Each of the past three decades has had substantially worse drought than any decade over the last 150 years.” 

For all of summer 2021, the U.S. Drought Monitor classified up to 90 percent of California as experiencing “exceptional” or “extreme” drought. 

“The last two years in California have brought compound drought conditions – effectively, very dry winters followed by relentless summer heat and atmospheric aridity,” explained John Abatzoglou, a climate scientist at the University of California, Merced. “This has left soil and vegetation parched across much of California, so the landscape is capable of carrying fire that resists suppression.”

Daniel Swain, a climatologist at UCLA, noted that one of the most direct ways that climate change is influencing California fires is by dialing up the temperature. “Heat essentially turns the atmosphere into a giant sponge that draws moisture from plants and makes it possible for fires to burn hotter and longer,” said Swain. 

Abatzoglou explained that some of the worst scenes across Northern California in 2020 were due to an extreme and unusual dry lightning siege in mid-August that ignited thousands of fires in one night. “But in 2021 I am less convinced of bad luck,” he said. “Climate change is aiding in the warming and the more rapid drying of fuels that predispose the land to large fires.”

Image Credit: NASA Earth Observatory

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By Chrissy Sexton, Earth.com Staff Writer