The devastating fires ripping through Los Angeles are fueled by unusual weather conditions that the National Weather Service called “about as bad as it gets in terms of fire weather.” And driving that worst-case scenario is a rapidly warming planet,

A heavy wet season in California’s past winters spurred more grass and brush, which then dried out quickly last summer. Those conditions are making fires worse.

While the causes of the largest fires are still under investigation, many factors led to the quick-spreading blazes.