The Earth just suffered one of the most extreme wildfire years on record, and scientists say human-driven climate change is the cause.
A radical new analysis, the Wildfire Status Report 2024-25finds that human-driven global warming dramatically increased the intensity and scale of forest fires Around the world, in some regions, severe fire seasons are 25 to 35 times more likely than they would have been in a colder world.
The international study combines satellite data, reanalysis of climate and land surface models to show how heat, drought and vegetation changes converged in record fires from the Amazon to California.
“Land surface models simulate how climate, vegetation and fire interact on the Earth’s surface,” said Douglas Kelley, a land surface modeler at the UK Center for Ecology and Hydrology (UKCEH) and co-director of the Annual report on the status of forest fires, he told Space.com. Kelley and his collaborators used two approaches to study the impacts of global wildfires: They first ran thousands of simulations of past fire seasons with and without the effects of human-caused climate change. They then looked at models of Earth’s vegetation to see how plant growth and death can produce fuel for wildfires. “Together, these approaches show how climate change has already influenced major fires and what the future holds,” Kelley said.
The team estimated that from March 2024 to February 2025, wildfires burned 3.7 million square kilometers (1.4 million square miles), an area larger than the size of India.
Certain regions experienced truly astonishing spikes. The fire emissions were higher than normalBolivia experienced the highest total carbon dioxide emissions this century (771 million tons), while Canada had its second year of reaching more than one billion tons of CO2 emissions. Brazil’s Pantanal region, considered the world’s largest wetland, had six times the area’s average carbon dioxide emissions.
Ash carbon dioxide helps contribute to greenhouse gases In our atmosphere, these emissions increases are helping to drive a positive feedback loop, further increasing global warming conditions, which, in turn, can lead to more extreme wildfires.
The most striking finding for the team was how clearly climate change emerged as a variable driving the intensity of wildfire seasons around the world.
“Wildfires are shaped by a confusing mix of climate, vegetation, land use and chance, factors that typically make event-scale attribution incredibly difficult. To fully reflect that complexity, we pushed our methods to explore thousands of different ways climate, people and ecosystems could interact to influence fire,” Kelley said.
“Yet despite all those possibilities, the conclusion hardly wavered: Human-driven climate change has increased the likelihood of these extreme fires and amplified the amount of land burned… Science has now advanced to the point where the climate signal is unambiguous. But what’s troubling is that climate change itself has advanced so much that this signal is visible in every extreme fire event we evaluate,” Kelley said.
The human and ecological cost
The 2024 and 2025 wildfires killed more than 200 people worldwide, including 100 people in Nepal, 34 people in South Africa and 30 people in Los Angeles. The Southern California fires alone forced 150,000 evacuations and caused approximately $140 billion in damages. Similarly, fires in Canada’s Jasper National Park alone cost more than $1 billion in damages, while Brazil’s Pantanal agribusiness sector lost more than $200 million due to wildfires.
In addition to carbon emissions, the impacts on air quality were also significant. Fine particle pollution from the fires in Brazil reached up to 60 times greater than the safety limits established by the World Health Organization, exposing hundreds of millions of people to toxic smoke.
Watch the Earth burn from space
For scientists, much of this evidence comes from low earth orbit. Satellites like NASA’s Terra and Aqua satellites They have become indispensable for detecting active fires, mapping burn scars and monitoring air pollution caused by smoke plumes.
Those spatial observations were fed directly into wildfire status analysis, which used them to validate fire weather models and quantify the extent to which climate change has altered conditions on the ground.
The research team says future versions of the report will rely even more on upcoming hyperspectral sensors and next-generation Earth observation satellites, which can track vegetation dryness, fuel loads, and even early-stage ignition events in near real time.
For researchers like Kelley, the question then becomes: what can humanity do about it?
“We address this in our briefing for policymakers, especially around climate finance and how wildfires affect nature-based climate solutions. However, we have not yet been in a position to fully explore how local fire management decisions influenced each event: what worked, what didn’t work, and what we can learn. Advances in scientific methods and continued study time will allow us to do this, and it is a key area for future work,” Kelley said.
