Climate change is increasing the likelihood of catastrophic wildfires in Southern California and enabling fires to burn longer by increasing their ability to burn in ‘unfavorable’ conditions, two new studies show. Research published Wednesday in Nature found increasingly hot and dry conditions increase fires’ ability to keep burning overnight, when firefighters used to be able to rely on cooler nighttime temperatures lowering fire intensity. Climate change, caused mainly by the extraction and combustion of fossil fuels, is worsening droughts, and making hot days hotter and more frequent, both of which supercharge wildfires.

“Our nights have been warming more than our days have been warming as a function of human-caused climate change, and that’s having a direct impact on fires,” Jennifer Balch, lead author of the study and director of the Earth lab at UC-Boulder, told the Washington Post. “We’re losing the brakes on fires in terms of the cooling and moisture accumulation that happens at night.”

Southern California fires

A separate paper published today in Communications Earth & Environment found climate change could double the number of “large fire days” in Southern California by 2100 without immediate emissions cuts. “When it’s hot for a long time it leads to these megafires that are resistant to fire suppression practices,” Aurora Gutierrez, a project specialist in UC-Irvine, told The Guardian. “In extreme conditions like this, whatever is going to burn is going to burn – and you can’t really do much to stop it.”

“It’s a roll of the dice,” Glen MacDonald, a professor of geography at UCLA and the lead author of the study, concurred, ” but we are loading them with more and more days where you have this high probability of a fire and that spark has a greater opportunity to occur when it’s really going to cause damage.” (Night fires: Washington Post $, CNN; Southern California: The Guardian; Climate Signals background: Wildfires, Drought, Extreme heat and heatwaves)

Airport Fire burns uncontrolled, fueled by dry brush

The Airport Fire, fueled by wind and dry brush ignited Wednesday near a regional airport just outside Bishop, California. The fire burned 1,800 acres in about seven hours – more than three football fields every minute — on Wednesday and was completely uncontained Wednesday night. It is now the state’s biggest fire of 2022. (LA Times $, AP, KOLO, USA Today, KEYT; Climate Signals background: Wildfires)