By Nicola Twilley
Throughout the twentieth century, federal policy focussed on putting out fires as quickly as possible, but preventing megafires requires a different approach.
Six of the ten worst fires in California’s history have occurred in the past eighteen months, and last year’s fire season was the deadliest and most destructive on record. More than a hundred people were killed, and more than seventeen thousand homes destroyed. Experts have warned that this year’s fire season could be even worse, in part because record-breaking rains early this year spurred the growth of brush and grasses, which have since dried out, creating more fuel. Governor Gavin Newsom proclaimed a wildfire state of emergency in March, months before fire season would normally begin.
The tools and techniques capable of stopping megafires remain elusive, but in the past few decades a scientific consensus has emerged on how to prevent them: prescribed burns. When flames are kept small and close to the ground, they clear the leaf litter, pine needles, and scrub that fuel wildfire, and consume saplings and low-level branches that would otherwise act as a ladder conveying fire to the canopy. With the competing vegetation cleared out, the remaining trees grow larger, developing a layer of bark thick enough to shield them from all but the hottest blazes. California’s state legislature recently passed a bill earmarking thirty-five million dollars a year for fuel-reduction projects.
“And yet no one is actually burning,” Jeff Brown, the manager of a field station in the Tahoe National Forest, told me when I visited him there recently. Although prescribed burns have been part of federal fire policy since 1995, last year the Forest Service performed them on just one per cent—some sixty thousand acres—of its land in the Sierra Nevada. “We need to be burning close to a million acres each year, just in the Sierras, or it’s over,” Brown said. The shortfall has several causes, but, some fifteen years ago, Brown set himself the almost impossible task of devising a plan for the forest he helps maintain that would be sophisticated enough to overcome all obstacles. Now he is coördinating an urgent effort to replicate his template across the Sierra Nevada.