Wildfires burn across every inhabited continent, and their frequency has been climbing for over two decades. While exact global counts vary by how fires are detected and measured, satellite monitoring systems track hundreds of thousands of active fire events each year. The trend line is clear: fires are getting more frequent, larger, and more destructive, particularly in North America, Latin America, and Africa.
Global Wildfire Frequency Is Rising
Researchers at the University of Maryland found a statistically significant global increase in fire-related forest disturbance from 2002 to 2024, with only subtropical regions bucking the trend. North America saw the sharpest jump, with fire-related forest loss rising 3.7 times over the previous two decades. Latin America followed closely at 3.4 times, Africa at 2.4 times, and Eurasia also showed significant upward trends.
In the United States alone, researchers identified 6,212 wildfire burn zone disasters between 2000 and 2025. The annual count ranged from as few as 61 in 2001 to 570 in 2011, with a median of 217 per year and a clear increasing trend over the 25-year period. That pattern mirrors what’s happening globally: not just more fires, but more fires reaching sizes and intensities that cause serious damage to communities and ecosystems.
When and Where Fires Peak
Wildfire activity follows predictable seasonal rhythms tied to temperature and rainfall. In the Northern Hemisphere, fire season runs from May through October, peaking in July and August when heat and dryness are at their worst. Southern Hemisphere fire seasons are offset by about six months. In tropical South America and sub-Saharan Africa, fires typically peak in September and October. In southeastern Australia, the most dangerous period is January and February.
Africa consistently accounts for a large share of global fire activity, mostly from agricultural burning and savanna fires across the continent’s tropical belt. These fires tend to be lower intensity than the forest fires that dominate headlines in North America and Australia, but their sheer number and extent make Africa a major contributor to global fire statistics. The boreal forests of Canada and Siberia have also become increasingly active, with record-breaking fire seasons in both regions in recent years fueled by unusually warm and dry conditions.
What Causes Most Wildfires
Human activity is responsible for the vast majority of wildfires worldwide. Lightning, the primary natural ignition source, accounts for roughly 10% of global forest fires. The remaining 90% stem from human causes: agricultural clearing, campfires, power lines, arson, discarded cigarettes, and equipment sparks. In tropical regions, deliberate burning to clear land for farming and ranching is the dominant driver. In populated areas of North America and Europe, accidental ignitions near roads, homes, and infrastructure are more common.
The distinction matters because human-caused fires tend to start near populated areas, which means they’re more likely to threaten homes and lives even when they’re relatively small. Lightning fires, by contrast, often ignite in remote wilderness areas and can burn for weeks before posing a threat to communities. However, some of the largest and most destructive fire seasons on record, including Canada’s 2023 season, were driven heavily by lightning ignitions during exceptionally hot, dry conditions.
Megafires Are Becoming More Common
The term “megafire” entered scientific literature in 2005 and has been used with increasing frequency since. While there’s no single universal definition, the most common threshold is a fire exceeding 10,000 hectares (about 25,000 acres, or roughly 38 square miles). Researchers have proposed additional categories for even larger events: “gigafires” exceeding 100,000 hectares and “terafires” exceeding 1,000,000 hectares.
A review of 84 studies documented 137 fires reported as megafires, with 94% exceeding the 10,000-hectare threshold. The vast majority, about 82%, occurred in forested areas rather than grasslands or shrublands. These are the fires that cause the most lasting ecological damage, because forests store enormous amounts of carbon and take decades or centuries to regrow. As temperatures rise and droughts intensify, the conditions that produce megafires are occurring more frequently in regions that historically experienced smaller, less intense burns.
The Economic Toll
Between 2014 and 2023, wildfires caused an estimated $106 billion in economic losses globally, with $74 billion of that covered by insurance, according to the UN Office for Disaster Risk Reduction. Both figures far exceeded losses from the previous decade. Since 1970, economic losses linked to wildfires have increased by about $170 million per year, driven largely by the expansion of housing and development into fire-prone areas.
These numbers capture only direct costs like destroyed buildings, damaged infrastructure, and firefighting expenses. They don’t account for health impacts from wildfire smoke, lost productivity, displacement costs, or long-term ecological damage. Smoke from large fires can degrade air quality across entire continents, as North Americans experienced during Canada’s 2023 fire season when haze blanketed cities thousands of miles from the nearest flame.
Carbon Emissions From Fire
Wildfires are a significant source of carbon dioxide, and the numbers are growing. During the fire season spanning March 2024 to February 2025, over 8 billion tonnes of CO₂ entered the atmosphere from fires worldwide, 9% above the long-term average. Severe fires burning through carbon-rich forests and wetlands in the Americas drove much of that increase.
This creates a feedback loop that makes the problem harder to solve. Fires release stored carbon into the atmosphere, which contributes to warming, which dries out vegetation and creates conditions for more fires. Forests that historically acted as carbon sinks, absorbing more carbon than they released, can flip to becoming net carbon sources after repeated or severe burning. In boreal and tropical forests, where enormous amounts of carbon are stored in trees and soil, this feedback is particularly concerning because recovery takes so long that the carbon stays in the atmosphere for decades.