Publication Date April 11, 2016

Wildfires, Once Confined to a Season, Burn Earlier and Longer

United States
Trainees learned to dig a fire line at the Arizona Wildfire and Incident Management Academy at Embry-Riddle Aeronautical University in Prescott. The federal costs of fighting fires rose to $2 billion last year. Photo: Caitlin O'Hara, The New York Times

Fires, once largely confined to a single season, have become a continual threat in some places, burning earlier and later in the year, in the United States and abroad. They have ignited in the West during the winter and well into the fall, have arrived earlier than ever in Canada and have burned without interruption in Australia for almost 12 months.

A leading culprit is climate change. Drier winters mean less moisture on the land, and warmer springs are pulling the moisture into the air more quickly, turning shrub, brush and grass into kindling. Decades of aggressive policies that called for fires to be put out as quickly as they started have also aggravated the problem. Today’s forests are not just parched; they are overgrown.

In some areas, “we now have year-round fire seasons, and you can say it couldn’t get worse than that,” said Matt Jolly, a research ecologist for the United States Forest Service. “We expect from the changes that it can get worse"