Los Angeles Fires Indisputably Fueled by Climate Change 

The horrific wildfires that ripped through parts of the Los Angeles area last week were, like many disasters of this scale, the result of a perfect storm of circumstances. Unusually strong Santa Ana winds topped off decades of decisions about land management and urban planning—setting a stage for sparks (with a still unknown origin) that ignited some of the most destructive infernos in California’s admittedly fire-prone history.But contrary to the assertions of some politicians (notably President-elect Donald Trump and his nominee for Department of Energy chief, fracking company executive Chris Wright), the scientific evidence is clear that climate change helped fuel the ferocity of these blazes. Hotter, drier conditions and increasing “weather whiplash” made the local vegetation much more flammable.“Is there a link between climate change and the broadly increasing risk/severity of wildfire in California? Yes; that much is clear at this point,” wrote climate scientist Daniel Swain on his blog, Weather West.If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.Unlike forest fires in other parts of the state, blazes in coastal southern California burn in grass and brush. This is an important distinction because year-to-year variations in the precipitation that falls during the winter wet season don’t substantially change the abundance of plants in forests. But in areas like those hit by the latest Los Angeles fires, more winter rains mean a lot more grass and brush growth come spring.When the summer dry season begins, all of that grass and brush dries up. And as global and local temperatures rise with the accumulation of greenhouse gases in the atmosphere, the atmosphere itself becomes “thirstier”—so it sucks up even more moisture from the ground and vegetation through evaporation. The drier the fuel, the more readily and fiercely it will burn when any spark arises.An analysis by University of California, Los Angeles, climate scientists found that vegetation in the area where Palisades and Eaton Fires ignited was 25 percent drier than it would have been in the absences of climate change. “We believe that the fires would still have been extreme without the climate change components noted above, but would have been somewhat smaller and less intense,” said the analysis’s authors in a press release from U.C.L.A. A separate analysis by the ClimaMeter, a group of climate scientists working to provide rapid assessments of weather extremes using climate models, also found that climate change had amplified the dry conditions—with temperatures up to five degrees Celsius (nine degrees Fahrenheit) hotter and conditions up to 15 percent drier in the past few decades than in the period from 1950 to 1986.But climate change doesn’t just make things wo