Human-caused climate change increased the likelihood and intensity of the hot, dry and windy conditions that fanned the flames of the recent devastating Southern California wildfires, a scientific study found.
But the myriad of causes that go into the still smoldering fires are complex, so the level of global warming’s fingerprints on weeks of burning appears relatively small compared to previous studies of killer heat waves, floods and droughts by the international team at World Weather Attribution. Tuesday’s report, too rapid for peer-review yet, found global warming boosted the likelihood of high fire weather conditions in this month’s fires by 35% and its intensity by 6%.
The study also found California’s dry season has increased by 23 days and the lack of rain in October, November and December was more than twice as likely now than in pre-industrial times, but because of limitations on the data, researchers couldn’t statistically pinpoint these to both climate change and the specific fires this month, Otto said. But she said “the rains are decreasing—that is because of human-induced climate change.”
Then add in strong winds to whip and spread flames.
Mike Flannigan, a Canadian fire scientist who wasn’t part of the research, said one key to him is the fire season extending longer and “increasing the chance a fire will start during peak Santa Ana winds.”