WASHINGTON – Earth’s nastiest and costliest wildfires are blazing four times more often now than they did in the 1980s because of human-caused climate change and people moving closer to wildlands, a new study found.

A study in the journal Science looks at global wildfires, not by acres burned which is the most common measuring stick, but by the harder to calculate economic and human damage they cause. The study concluded there has been a “climate-linked escalation of societally disastrous wildfires.”

A team of Australian, American and German fire scientists calculated the 200 most damaging fires since 1980 based on the percentage of damage to the country’s Gross Domestic Product at the time, taking inflation into account. The frequency of these events has increased about 4.4 times from 1980 to 2023, said study lead author Calum Cunningham, a pyrogeographer at the Fire Centre at the University of Tasmania in Australia.

“It shows beyond a shadow of a doubt that we do have a major wildfire crisis on our hands,” Cunningham said.

About 43% of the 200 most damaging fires occurred in the last 10 years of the study. In the 1980s, the globe averaged two of these catastrophic fires a year and a few times hit four a year. From 2014 to 2023, the world averaged nearly nine a year, including 13 in 2021. It noted that the count of these devastating infernos sharply increased in 2015, which “coincided with increasingly extreme climatic conditions.” Though the study date ended in 2023, the last two years have been even more extreme, Cunningham said.

Europe and North America lead in the number of these economically damaging fires. It’s especially worse in the Mediterranean around Greece, Italy, Spain and Portugal and in the Western United States around California, because of the climate prone to sudden dryness, worsened by global warming, Cunningham said.

The researchers also found a tripling in how often a single fire killed at least 10 people, such as 2018’s Paradise fire, 2023’s Lahaina fire and those in Los Angeles in 2025.

Cunningham said often researchers look at how many acres a fire burns as a measuring stick, but he called that flawed because it really doesn’t show the effect on people, with area not mattering as much as economics and lives. Hawaii’s Lahaina fire wasn’t big, but it burned a lot of buildings and killed a lot of people so it was more meaningful than one in sparsely populated regions, he said.

“We need to be targeting the fires that matter. And those are the fires that cause major ecological destruction because they’re burning too intensely,” Cunningham said.

But economic data is difficult to get with many countries keeping that information private, preventing global trends and totals from being calculated. So Cunningham and colleagues were able to get more than 40 years of global economic date from insurance giant Munich Re and then combine it with the public database from International Disaster Database, which isn’t as complete but is collected by the Catholic University of Louvain in Belgium.

The study looked at “fire weather” which is hot, dry and windy conditions that make extreme fires more likely and more dangerous and found that those conditions are increasing, creating a connection to the burning of coal, oil and natural gas.

“We’ve firstly got that connection that all the disasters by and large occurred during extreme weather. We’ve also got a strong trend of those conditions becoming more common as a result of climate change. That’s indisputable,” Cunningham said. “So that’s a line of evidence there to say that climate change is having a significant effect on at least creating the conditions that are suitable for a major fire disaster.”

If there was no human-caused climate change, the world would still have devastating fires, but not as many, he said: “We’re loading the dice in a sense by increasing temperatures.”

There are other factors. People are moving closer to fire-prone areas, called the wildland-urban interface, Cunningham said. And society is not getting a handle on dead foliage that becomes fuel, he said. But those factors are harder to quantify compared to climate change, he said.

“This is an innovative study in terms of the data sources employed, and it mostly confirms common sense expectations: fires causing major fatalities and economic damage tend to be those in densely populated areas and to occur during the extreme fire weather conditions that are becoming more common due to climate change,” said Jacob Bendix, a geography and environment professor at Syracuse University who studies fires, but wasn’t part of this research team.

Not only does the study makes sense, but it’s a bad sign for the future, said Mike Flannigan, a fire researcher at Thompson Rivers University in Canada. Flannigan, who wasn’t part of research, said: “As the frequency and intensity of extreme fire weather and drought increases the likelihood of disastrous fires increases so we need to do more to be better prepared.”

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