The Los Angeles fires in January. Blazes in Canada in 2024. Hawaii burning in 2023. It seems as though every year, the planet has more huge wildfires that devastate communities. But so far, the science has been sparse on whether the most economically damaging fires really are on the rise.
Now, a new study has found that catastrophic wildfires with both high economic costs and loss of human life are, indeed, happening more often, and that those fires are strongly linked to climate change. The past decade in particular has seen a significant uptick in costly, deadly fires, according to the study, which was published on Thursday in the journal Science.
“It’s a pretty big wake-up call,” said Brian Harvey, a professor of forest fire science at the University of Washington who was not involved in the new study. “We live on a flammable planet, and that flammability is increasing.”
Fire is a natural and beneficial part of many ecosystems. But climate change can make fire seasons longer, hotter and drier. On top of that, humans have been artificially suppressing wildfire for decades, which creates more fuel for fires, and moving deeper into fire-prone areas.
That sets the stage for damaging fires in urban settings, said Calum Cunningham, a wildfire scientist at the University of Tasmania who led the new study.
“We’ve predisposed fire to occur under the most extreme conditions, where there’s lots of fuel, on the worst possible days,” Dr. Cunningham said. “That leads to catastrophic, uncontrollable fires.”
Some earlier research did not find evidence that disastrous wildfires are becoming more common. A 2016 paper, for instance, looked for trends in damaging fires worldwide from 1984 to 2013 and found little evidence supporting an increase in direct losses from fire.
But the climate is changing rapidly, and in every year following the end of that study, several huge fires occurred. So, Dr. Cunningham wanted to know: Are these big, damaging fires really getting more frequent, or is that just a perception?
To find out, the researchers used two data sets, one public and one private, of wildfire-related costs and fatalities around the world between 1980 and 2023. They identified the 200 most costly fires, measuring losses relative to each country’s gross domestic product to avoid biases against lower-income countries. They also included wildfires with 10 or more direct fatalities, bringing the total of most-damaging wildfires to 242.
Based on those 242 wildfires, the researchers found the number of disastrous wildfires had increased more than fourfold from 1980 to 2023. Nearly half of the fires, 43 percent, were in the last 10 years of the record. Additionally, there were 43 wildfire disasters that cost more than $1 billion in that same period. (The Trump administration said in May it would stop tracking billion-dollar disasters that occur in the United States.)
The findings contrast with those of the 2016 paper, now not even a decade old. But Cristina Santín, a wildfire scientist with the Spanish National Research Council and an author of that earlier paper, was not surprised that the new study had found a different answer from hers. She was glad to see an updated look at trends in damaging wildfires.
“This is proof that things are getting worse,” Dr. Santín said. “We need to adapt to live with fire. This is our reality, and it’s not going anywhere.”
The disastrous fires were largely clustered in the western part of North America, southern Europe and southern Australia, and mostly in affluent areas with high property values — but not exclusively.
Wildfire disasters also struck in the tropics and the far north, mostly driven by unusually strong droughts, and in more rural regions like Nepal that don’t often get Western media coverage. They hit every continent except Antarctica.
Dr. Cunningham put it simply. “They’re everywhere,” he said.
The researchers then checked to see if the increase in disastrous wildfires had any associations with climate change.
They found that the fires were closely associated with “fire weather,” which includes strong, dry winds, high temperatures and drought. Other research has found that fire weather is on the rise as a result of climate change.
“It’s clear that these events are driven by extreme weather,” Dr. Cunningham said. Climate change isn’t solely responsible for all the disastrous wildfires in the study, he stressed, but “it sets the stage” for them.
“Climate change is creating more opportunities for a catastrophic fire,” he said.
Together, the findings are a “pretty strong collection of evidence” that socioeconomic costs from disastrous wildfires are increasing, and that climate is a big part of the equation, Dr. Harvey said. “This really hammers home the fact that things are rapidly changing, and we really need to better understand them to be able to address them.”