Thousands of people Wednesday were forced to flee a rapidly spreading wildfire approaching the California town of Mariposa near Yosemite National Park.
Just a day after Gov. Jerry Brown declared a state of emergency for Mariposa County, the Detwiler Fire had nearly doubled in size, covering roughly 46,000 acres and threatening scores of homes and other structures. [Update: By Thursday morning, the fire had spread to 70,000 acres and was only 10 percent contained, according to Cal Fire.]
The blaze is among nearly 40 large active fires burning across 12 western states as of Wednesday, according to the National Interagency Fire Center. More than 4 million acres have burned since the start of 2017, the site reports, compared to 2.7 million acres in the same period last year.
So why do wildfires seem to be getting more ferocious each year? Warmer conditions, drought and other impacts of climate change are major contributors, but there's more to the story. Comic journalist Andy Warner explains the fiery history of how we got here.