WildfiresClimate Change Making Western Wildfires in U.S. Worse
Wildfires have burned a record-breaking 1.25 million hectares in California as of Saturday. Washington state is enduring its second-largest area burned. A half-million people are under a fire evacuation warning or order in Oregon, one-tenth of the state’s population. The devastation is not unexpected. Climate experts have been sounding the alarm for a long time. Wildfires need dry plants to burn, and climate change is helping increase the supply.
Wildfires have burned a record-breaking 1.25 million hectares in California as of Saturday. Washington state is enduring its second-largest area burned. A half-million people are under a fire evacuation warning or order in Oregon, one-tenth of the state’s population.
The devastation is not unexpected. Climate experts have been sounding the alarm for a long time, said University of California, Merced, wildfire expert LeRoy Westerling.
“We’ve been doing modeling and simulations for years now that indicate that these really severe widespread fire seasons are coming, beyond anything that we’ve really experienced in the historical record,” he said. “And we’re seeing that emerge in real time, year by year here in California and around the western United States. So in that sense it’s not surprising at all.”
On the other hand, he added, living through it is another story. “It feels very real and very surprising every year as it ratchets up and gets a little more horrible.”
Heating Up, Drying Out
Wildfires need dry plants to burn, and climate change is helping increase the supply, Westerling said.
Higher temperatures mean flammable materials dry out faster. California and Oregon have already warmed about 1.1 degrees Celsius on average since the start of the 20th century, and Washington is about 0.8 degrees C warmer, according to the National Oceanic and Atmospheric Administration. High-temperature extremes are becoming more common, too, especially the number of warm nights.
The warming climate affects water supplies throughout the year. Mountain snowmelt is a critical long-lasting source of water in much of the region. But less precipitation is falling as snow and more as rain, which runs off faster. That means less water is available when the dry summer months arrive.
Those summers have been especially dry. According to a recent study, the Southwestern United States is the second-driest it has been in more than 1,000 years. Only the late 1500s were drier. While the region is dry to begin with, the study found that climate change has turned what would have been a moderate drought into a multidecade megadrought.
