Why is California burning?

FOR DECADES environmentalists have warned that the world is going to burn. Mostly, they meant it figuratively. But footage of fires sweeping through the Siberian steppe, the Amazon forest, parts of Australia and now, once again, California, make it easy to believe the planet is, literally, on fire. New infernos have been whipped up by strong winds and scorching temperatures across the Golden State. On September 7th PG&E, a utility serving northern California, shut off the power supply to tens of thousands of homes in an attempt to stop live lines from sparking more blazes. So far this year, California has seen more than 2.5m acres (1m hectares) burned and more than 3,700 structures destroyed—all before the autumn months when the Santa Ana winds normally stir up the worst of the annual blazes. With over three months remaining of this year’s fire season, few doubt the state is facing its worst yet.