Wildfires today are less frequent, but more destructive than they once were, UA study shows

Climate change has driven a significant increase in wildfires in recent decades. But in a new study published in the journal Nature Communications, University of Arizona researchers show North American forests still aren’t burning as often as they did historically, and that’s a problem.

The researchers looked over centuries of tree ring data from across North America.They found that widespread wildfires were happening every 10 to 20 years before the 1880s. Since then, the area burned annually has been much smaller.

From 1984 to 2022, the researchers say North America had only about a quarter the number of wildfires that it would have had historically. Major blazes in the last few years still have not closed the gap.

That means, when fires do happen now, they’re much more destructive and intense, since there’s more brush and dead wood to burn.

“Although contemporary fire extent is not unprecedented across many North American forests, there is abundant evidence that unprecedented contemporary fire severity is driving forest loss in many ecosystems and adversely impacting human lives, infrastructure, and water supplies,” the study’s authors wrote.