Daniel Swain in National Geographic: How climate change primed California’s power shutdown

Over the past century, California has warmed by about 3 degrees Fahrenheit, more than the global average of about one degree Fahrenheit. Hotter air draws water out of plants and soils more efficiently than cool, leaving the trees, shrubs, and rolling grasslands of the state dry and primed to burn.

Crucially, that effect increases exponentially with every degree of warming, explains Daniel Swain, a climate scientist at the University of California, Los Angeles. That means that today’s hotter, climate-changed air is much more effective at drying vegetation to a crackle than it was 100 years ago.