The Powerhouse Fire burned about 30,000 acres in the Angeles National Forest in the spring of 2013.
Climate change is forcing the US Forest Service to rethink how it fights large wildfires. Global warming has increased the intensity of fires, forcing the USFS to spend more and more of its money fighting them. Now the agency has decided that it should be less aggressive in attacking big blazes, so long as they are not threatening property.
In 1991, the US Forest Service’s spent 13 percent of its budget on fire management. Today, because of climate change, that figure is more than 50 percent, officials say.
The change is visible at the top. Three years ago, the USFS added a chief climate advisor. Agency veteran Dave Cleaves holds the job; he’s been with the Forest Service for more than 20 years. He says forest managers used to consider global warming as a future problem, "but now we’re finding more and more it is an issue of the present and the future."
Headwaters Economics, a Montana think tank, found that when the temperature is one degree warmer, fires burn on average three times as much terrain. Headwaters economist Roy Rasker said the cost of fighting larger fires could overwhelm local, state and even federal budgets.
The Forest Service already cuts underbrush and thins tree stands to minimize risks. But agency predictions of increasing fire intensity suggest that, even with these tactics, the amount of forestland vulnerable to burning will increase in the years to come, says U.S. Forest Service fire researcher Elizabeth Reinhart.
That reality is changing federal fire management. The Forest Service has been successful over the decades fighting fires with personnel-heavy attacks that aim to shut a blaze down right when it starts. Reinhart and other federal officials say sticking with that strategy is costly, and could overwhelm other necessary work in the forest.
"So in some cases, rather than direct aggressive suppression tactics, we’re able to monitor wildfires to stop its movement in one direction while letting it burn in another," Reinhart says. "This sets up the landscape to be more resilient to the next wildfire."
Reinhart and other scientists say human development that encroaches on nature -- such as in many of southern California's foothills -- complicates this strategy. The Headwaters Economics study concluded that 35 percent of the cost of firefighting in California is related to protecting property.