While climate change didn’t itself cause the fire, Swain explains, it played a “starring role.” Summers in the state have been getting hotter, and autumns have been getting both warmer and drier. “While the exact level of dryness in a particular year is somewhat random, less precipitation in autumn & spring—California’s ‘shoulder seasons’—has long been a projected outcome of climate change,” he adds.
The result is a practical tinder box of dry vegetation at a time when California tends to experience strong offshore winds—a ready-made recipe for fast-spreading wildfires. Urban development in areas that are already at risk for wildfires has only compounded the problem.
Swain and his colleagues warned about the growing threat of massive fires in an August story for The Guardian. Climate change, they wrote, has acted as a “threat multiplier.”
Notable, too, is that climate change doesn’t seem to be increasing the frequency of wildfires so much as their character. It’s making them more intense, and likely to spread faster. “In California,” the researchers noted, “not all wildfires are forest fires—some of the state’s deadliest and fastest-moving fires have burned primarily in shrubs and oak woodlands. With climate change tipping the scales in favor of hotter temperatures and drier conditions across the entire landscape, vegetation of all types is becoming more flammable.”