Wildfires almost always have a human origin

Mendocino Fire (Photo by Justin Sullivan, Getty Images)

Though the wildfires blazing throughout the Western and Southern U.S. get bigger and last longer because of climate change, almost all of them are started by a human, either on purpose or by accident. Sometimes because of what people do, as when a flat tire dragging on asphalt sparked the Carr Fire in California, and sometimes because of what people don't do, such as when trees around rural power lines are poorly pruned or nature-protection policies don't allow for many controlled fires to burn dead vegetation.

"Experts also worry that not enough attention is given to all the ways people have made the problem of wildfires worse. Population growth in California means there are more people on the roads — cars are a prime culprit in wildfires — and more homes built in wilderness areas," Tim Arango and Inyoung Kang report for The New York Times.

Stephen Pyne, a fire historian at Arizona State University, told the Times that he worries the public has gotten used to wildfires and won't be willing to talk about how to prevent them: "I’m beginning to think of these like mass shootings. A shooting happens in a grade school and nothing changes."