New Data Confirms: Forest Fires Are Getting Worse

The latest data confirms what we’ve long feared: Forest fires are becoming more widespread and destructive around the globe. 

Using data from researchers at the University of Maryland, recently updated to cover the years 2001-2024, we calculated that forest fires now burn more than twice as much tree cover each year as they did two decades ago.¹

This increase in fire activity has been starkly visible in recent years. Record-setting blazes are becoming the norm, with four of the five worst years for global forest fires occurring since 2020.

2024 was the most extreme year for forest fires on record, with at least 13.5 million hectares of forest burned — an area roughly the size of Greece. This surpassed the previous record of 11.9 million hectares, set in 2023, by about 13%. And some estimates suggest the true toll of 2024’s fires may have been even higher.

Last year was the first time that major fires raged across both tropical and boreal forests. Brazil, Bolivia, Russia and Canada all experienced some of their worst fire seasons since satellite-based monitoring began in 2001. Extreme wildfires in South America were particularly severe in 2024, accounting for roughly one-quarter of all fire-related tree cover loss globally.

These fires aren’t just impacting the world’s forests. They’ve destroyed homes and infrastructure, polluted drinking water and caused billions of dollars in property damage. Dangerous wildfire smoke is estimated to cause over 1.5 million deaths each year. As fires worsen, so do their impacts, underscoring the urgency of getting them in check.

Fires Are Emerging as a Top Driver of Forest Loss

As fires worsen — including in historically low-risk areas, like the tropics — they are becoming an increasingly prevalent driver of global forest loss. Fires accounted for almost half (44%) of all tree cover loss per year between 2023 and 2024. This marks a sharp rise from 2001-2022, when fires accounted for about one-quarter of annual tree cover loss on average. Coupled with other persistent drivers, like agriculture and logging, this is part of the reason forest loss has remained stubbornly high, despite countries’ promises to combat it.

Here, we unpack what’s behind these concerning trends and examine some of the places most impacted by increasing forest fires.

Climate Change Is Making Fires Worse

Climate change is one of the major drivers behind increasing fire activity. Extreme heat waves are already 5 times more likely today than they were 150 years ago and are expected to become even more frequent as the planet continues to warm. Hotter temperatures dry out the landscape and help create the perfect environment for larger, more frequent forest fires.

When forests burn, they release carbon that is stored in the trunks, branches and leaves of trees, as well as carbon stored underground in the soil. As forest fires become larger and happen more often, they emit more carbon, further exacerbating climate change and contributing to more fires as part of a “fire-climate feedback loop.”

This feedback loop, combined with the expansion of human activities into forested areas, is driving much of the increase in fire activity we see today. As climate-fueled forest fires burn larger areas, they will affect more people and impact the global economy.

Rising Temperatures Are Fueling Fires in Boreal Forests

More than 60% of all fire-related tree cover loss between 2001 and 2024 occurred in boreal regions. Though fire is a natural part of how boreal forests function ecologically, fire-related tree cover loss in these areas has risen rapidly, increasing by about 160,100 hectares per year over the last 24 years.

Climate change is the main reason for this. Northern high-latitude regions are warming at a faster rate than the rest of the planet, contributing to longer fire seasons, greater fire frequency and severity, and larger burned areas in boreal forests.

Russia, for example, had its three worst fire seasons on record between 2020 and 2024. 2021 was the most severe, with at least 5.4 million hectares of forest burned. This was due in part to prolonged heatwaves that would have been practically impossible without human-induced climate change.

In Canada, record-breaking wildfires burned almost 7.8 million hectares of forest in 2023; about 6 times the country’s annual average for 2001-2022. The flames were largely fueled by warmer than average temperatures and drought conditions, with some parts of the country experiencing temperatures up to 10 degrees C (18 degrees F) above normal. The trend continued in 2024, with over 4 million hectares of forest burned. And Canada’s 2025 fire season was off to its second-worst start as of July, based on fire alert data going back to 2001.

This trend is worrying for several reasons. Boreal forests store 30%-40% of all land-based carbon, making them critical climate stabilizers. Most of this carbon is stored underground, including in permafrost, and has historically been protected from the infrequent and milder fires that occur naturally. But changes in climate and fire activity are melting permafrost and making soil carbon more vulnerable to burning.

In addition, severe fires can drastically alter the structure of boreal forests — effectively eliminating coniferous species like black spruce, which normally dominate the landscape, and allowing deciduous trees to take their place. Such changes could have wide-ranging impacts on biodiversity, soil dynamics, fire behavior, carbon sequestration and cultural traditions. In some extreme cases, trees may fail to regrow at all.

These shifting forest dynamics could eventually turn boreal forests from a carbon sink (an area that absorbs more carbon than it emits) into a source of carbon emissions. In fact, recent research shows that boreal forests are already losing their ability to store carbon.

Agriculture and Forest Degradation Stoke Fires in the Tropics

In contrast to boreal forests, stand-replacing fires are not a usual part of the ecological cycle in many tropical forests. Yet fires are increasing there as well. Over the last 24 years, fire-related tree cover loss in the tropics increased at a rate of about 47,200 hectares per year, peaking in 2024 with over 4 million hectares lost — more than the previous three years combined.

Even the world’s tropical rainforests, historically protected from fire by heavy rainfall, are now burning at alarming rates. In 2024, fires were responsible for nearly half (48%) of all tree cover loss in tropical primary forests like the Amazon and Congo Basin,² which are critical to storing carbon, protecting biodiversity and regulating local climates. It was the first year that fires surpassed agriculture as the leading cause of forest loss in these regions.

Almost all fires that occur in the tropics are started by people, rather than by natural causes like lightning strikes. Managed fires are commonly used in the region to clear land for new pasture or agriculture. But these fires can escape and escalate, with warmer and drier conditions fueling their spread. Deforestation and forest degradation associated with agricultural expansion also make forests in these regions more vulnerable to fires by contributing to rising temperatures and dried-out vegetation.

In Bolivia, for example, agricultural expansion and droughts have led to a significant increase in fire activity over the last two decades. Fires burned more than a million hectares of forest in the country in 2024, a nearly 114% increase over the previous record set in 2019. Peru and Brazil also experienced their worst and second worst fire seasons, respectively, in 2024, with most of the loss occurring in primary forests.

Similar to boreal forests, increased fire activity in the tropics is causing higher carbon emissions. Previous studies found that in some years, forest fires accounted for more than half of all carbon emissions in the Brazilian Amazon. This suggests the Amazon basin may be nearing or already at a tipping point for turning into a net carbon source.

Heatwaves and Development Increase Fire Risk in Temperate and Subtropical Forests

Historically, temperate and subtropical forests have burned less than boreal or tropical forests. Fires in subtropical forests, like the southeastern United States, eastern Australia, and many parts of the Mediterranean, have remained relatively stable over the last 24 years. But fires in temperate forests, including in the eastern United States, western Europe and parts of eastern Asia, are increasing by about 23,300 hectares per year.

Temperate and subtropical areas tend to contain a larger proportion of managed forests, which can house fewer species and store less carbon than natural ones. However, fires in these regions still pose significant risks for people and nature.

Climate change is the main driver behind the increasing fire activity in temperate forests. For example, heatwaves and summer droughts play a dominant role in driving fire activity across the Mediterranean basin. In 2022, record-breaking heat and drought in Spain resulted in more than 70,000 hectares of forest burned, the largest amount since 2001.

Land-use changes and shifting population patterns compound the impacts of climate change. In Greece, a combination of heatwaves, drought, and large plantations of highly flammable non-native species, like Eucalyptus, created ideal conditions for extreme wildfires in 2021 and 2023. In Europe more broadly, the abandonment of agricultural land in recent years has been followed by excessive vegetation growth that has increased fire risk.

In the United States, natural lands are rapidly being converted into “wildland-urban interfaces”: places where homes and other structures intermingle with trees and vegetation. This increases the risk of fire ignitions, damage and loss of life. In 2022, wildfires in the U.S. burned nearly 1 million hectares of forest and caused roughly $3.3 billion in damages. One of the largest fires that year, California’s Mosquito Fire, burned thousands of hectares of forest in and near areas classified as wildland-urban interfaces.

As human activities continue to warm the planet and reshape the landscape, deadly, multi-billion-dollar disasters like these will likely become more common. The destructive fires that swept through Los Angeles in early 2025 — among the deadliest and most damaging in California’s history — highlight the growing threat of wildfires in vulnerable forest-edge communities.

How Do We Reduce Forest Fires?

The causes of increasing forest fires are complex and vary by geography. Much has been written about how to manage wildfires and mitigate fire risk, but there is no silver bullet solution.

Climate change plays an important role in driving more frequent and intense fires. As such, there is no solution for bringing fire activity back down to historical levels without drastically reducing greenhouse gas emissions and breaking the fire-climate feedback loop. Mitigating the worst impacts of climate change is still possible, but it will require rapid and significant transformations across all systems.

In addition to climate change, human activity in and around forests makes them more susceptible to wildfires and is a key driver of fire-related tree cover loss in the tropics and elsewhere. Improving forest resilience by ending deforestation and forest degradation is key to preventing future fires. So is limiting nearby burning that can easily escape into forests, particularly during periods of drought. Incorporating wildfire risk mitigation into forest management strategies in fire-prone regions would help protect forest carbon and create jobs and support rural communities at the same time.

While data alone cannot solve this issue, the recent data on fire-related tree cover loss on Global Forest Watch, along with other fire monitoring data, can help us track fire activity in both the long term and in near-real-time to identify trends and develop targeted responses.

Editor’s note: This article was originally published in 2022. It was last updated in July 2025 to reflect the latest data on global forest fires.

Thanks to Mikaela Weisse, who contributed to an earlier version of this article.

^{1 We define forests as all natural, managed or planted trees with at least 30% canopy cover. All calculations are based on this threshold. Importantly, “forest loss” does not always mean permanent loss. Others, such as this recent paper led by University of Maryland, may use different methodologies and forest definitions. We encourage readers to consider a range of sources when exploring global forest loss trends.}

^{2 Minor discrepancies between the data in this analysis and our summary of global deforestation trends are due to differences in the spatial resolution and methodologies used. For more information about either dataset, contact James MacCarthy.}