Did climate change make the LA fires worse? It’s complicated

Strong winds, warm weather, dry brush and a lack of rain: All of those factors and more came together to make L.A.’s January wildfires some of the worst on record.

But were those conditions made worse by climate change?

Authors of a new study published in Earth System Science Data try to quantify the answer, writing that climate change probably made the Eaton and Palisades fires more likely and could have resulted in the burned area being 25 times larger than it would have been without climate change (though there’s a large range of uncertainty in that estimation).

“Those fires in January were just so much more difficult to control because it was so dry, because it was warmer,” said Crystal Kolden, professor and director of the Fire Resilience Center at UC Merced and a co-author of the paper. “And that is where that climate change signal is really strong.”

There’s a clear scientific consensus that climate change is associated with hotter temperatures, which can cause plants to dry out faster than they otherwise would.

However, there’s less certainty around other factors that played a role in January, according to Park Williams, a professor in the Department of Geography at UCLA, whose work was cited in the study but who did not participate in it.

It’s unclear if climate change is causing our rainy seasons to be delayed more often (as was the case in January), though models suggest a trend in that direction, Williams said.

There’s also uncertainty around whether climate change is exacerbating the whiplash between wet and dry years in Southern California — lots of fuel grew in the two wet years prior to a dry 2024.

And how it may be changing the Santa Ana winds, which normally do blow in January.

“These are all things where the effect of climate change is just much murkier,” Williams said.

The future of fire

Modeling our fire future here is further complicated by the highly variable fuel types, the weather, the homes and the vegetation across Southern California’s topographically complex terrain.

Some models may work well in wildlands like forests, where the main thing that’s burning is natural vegetation, Kolden said. But many hard-to-predict human factors are present in the wildland urban interface — places like the Pacific Palisades, where homes are built right up against open natural areas. Those variables can make the models less confident.

“ I think that it's important that people who are living in Southern California understand that actually in the greater L.A. area, coastal Southern California, we have not seen an increase in the number of fires or the area burned,” Williams said.

Northern California is another story, he said.

“The fingerprint of climate change is just unmistakable” with fires in the Sierra Nevada and North Coast.

What humans do next is perhaps the biggest X factor, Kolden said.

“What we always say is we can't model human adaptation,” Kolden said. “We don't model humans adapting to these changes and saying, ‘Yeah, you know what? We actually don't like having our houses burned down, so we're going to start hardening our homes.’”

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