California and the West, which have experienced a surge in wildfire during the last decade, can expect more of the same with global warming, according to a study published Tuesday.
“A lot of the West, California included, really does look like it’s headed into a more fire-prone future,” said Max Moritz, a UC Cooperative Extension wildfire specialist and lead author of a new paper that examined climate change’s likely effects on global fire patterns.
The American West will not be alone, according to the research, published in the journal Ecosphere. While the forecast for the next few decades is less certain, by century’s end, much of the world will experience more wildfire than it does now, the study concluded.
That includes the tundra and forests of the Far North, temperate grasslands and regions with a Mediterranean climate such as Southern California. Notable exceptions include tropical rain forests, where increased rainfall could actually decrease wildfire.
The team of UC Berkeley scientists who led the study adapted an approach that has been used to evaluate the effect of climate change on plants and animals and applied it to wildfire. They gathered global wildfire and climate data for roughly the last decade and examined climate variables that affect fuel availability.
Using 16 different global climate models, they then developed forecasts for the future. “Most of the previous wildfire projection studies focused on specific regions of the world, or relied upon only a handful of climate models,” said co-author Katherine Hayhoe, director of the Climate Science Center at Texas Tech University.
Rising temperatures lengthen the fire season and dry out vegetation, making it more flammable, especially in mountain forests. But the authors said that temperature is not the only, or necessarily even the dominant, factor in many landscapes where changing precipitation patterns will modify wildfire cycles.
More rain in the tropics could decrease fire. In other areas that are not so wet, it could increase plant growth, producing more fuel to burn. And while diminished rainfall dries out vegetation, it can also reduce fuel levels by stunting plant growth, cutting the potential for fire.
“Fire is not going anywhere,” Moritz said, adding that the study results emphasize the need “to rethink how we live with fire and take it more seriously.”