Wildfire simultaneity, or numerous large wildfires burning at the same time, will become at least twice as frequent by 2085, researchers are warning. A steadily increasing number of large wildland fires — and the number of acres burned — has occurred over the past few decades in the American West, but new research has found that simultaneous large fires will burn even more often.
“Future regional increases in simultaneous large Western USA wildfires” was published in the International Journal of Wildland Fire by the University Corporation for Atmospheric Research; it focused on wildfires that burned 1,000 acres or more between 1984 and 2015. Researchers used multiple fire indices to model how simultaneity will likely change over the next 60 years. The study also measured the fires by Geographic Area Coordination Centers to see whether some geographic areas might see greater increases compared with others.
Simultaneous wildfires were projected to increase in every area of the West. Not only were “bad years” projected to increase, but increases in simultaneity also led to more intense wildfires. Peak season for simultaneous wildfires was projected to become several weeks longer by the end of the century.
“The trend was particularly pronounced for the most severe wildfire seasons — those that currently occur only every 10 years on average,” the National Center for Atmospheric Research said. “In the future, such seasons may be expected to occur at least twice as often, and up to nearly five times per decade in the northern Rocky Mountains, which was the most affected region.”
The findings point toward a risk in an already understaffed and under-resourced wildland firefighting force. Because crews are transferred across the nation, or sometimes even across nations, to battle fires depending on when an area’s season peaks, an increase in peak season length could mean major challenges for firefighters and fire managers.
“Because firefighting decisions about resource distribution, pre-positioning, and suppression strategies consider simultaneity as a factor, these results underscore the importance of potential changes in simultaneity for fire management decision-making,” the study says.
Steps can reportedly be taken to lessen the future risk of simultaneous wildfires, including thinning forests, conducting prescribed burns, and increasing numbers of firefighting crews and equipment. But that will depend on how long it will take to make those changes.
“The strain on resources created by simultaneous fires can affect the ability to conduct prescribed burns and pursue other preventative action,” the center said.
