Study: Global Warming Made Catastrophic LA Fires 35% More Likely; Wet-To-Dry Weather Whiplash Now Baked Into The Cake
From the first reports of wildfires breaking out around Los Angeles earlier this month, scientists could say that climate change had worsened the blazes. Sure, wildfires would burn in California regardless of planetary warming, but extra-dry fuels had turned the landscape into tinder. The resulting blazes, fanned by 100-mile-per-hour Santa Ana wind gusts, burned 50,000 acres. They killed at least 28 people and destroyed more than 16,000 structures, causing perhaps hundreds of billions of dollars of damage and economic losses.
A more thorough analysis published Tuesday found that those extremely dry and hot conditions were about 35 percent more likely thanks to climate change. Rains starting in October normally dampen the Southern California landscape, reducing wildfire risk, but the almost nonexistent rainfall this autumn and winter was about 2.4 times more likely when compared to a preindustrial climate, according to the study by World Weather Attribution, a U.K.-based research group. The region now has 23 additional days of fire-prone conditions each year, the analysis found, meaning more opportunities for blazes to spread out of control. “Drought conditions are more frequently pushing into winter, increasing the chance a fire will break out during strong Santa Ana winds that can turn small ignitions into deadly infernos,” said Clair Barnes, a World Weather Attribution researcher at Imperial College London’s Centre for Environmental Policy, in a statement. “Without a faster transition away from planet-heating fossil fuels, California will continue to get hotter, drier, and more flammable.”
A major driver of these catastrophic wildfires is “weather whiplash,” the report notes. Wet seasons are getting wetter, a result of a hotter atmosphere being able to hold more moisture, while dry seasons are getting drier. In the two previous winters, Los Angeles got significant rainfall, leading to the explosive growth of grasses and shrubs. But then an atmospheric switch flipped, and the metropolis got almost no rainfall between May 2024 and this January, so all that extra vegetation dried out. “Very wet years with lush vegetation growth are increasingly likely to be followed by drought, so dry fuel for wildfires can become more abundant as the climate warms,” said Theo Keeping, a wildfire researcher at Imperial College London’s Leverhulme Centre for Wildfires and co-author of the report, in the statement.
In a separate analysis released on January 13, researchers at the University of California, Los Angeles, found that climate change could be blamed for roughly a quarter of the dryness of the vegetation that burned in the fires, which they described as a conservative estimate. The study also found that the region’s weather whiplash set the stage for disaster. “Under a warmer climate, you also have what people would call a ‘thirstier’ atmosphere trying to draw up as much moisture as it can,” said Chad Thackeray, a climate scientist at UCLA and co-author of the report.
EDIT
https://grist.org/climate/climate-change-los-angeles-wildfire-attribution/
= new reply since forum marked as read
