Human-caused fire has overtaken timber harvesting as the leading driver of loss across the world’s last unbroken forests, with fire now behind 39.9 per cent of the damage and harvesting cut to 20.3 per cent. That is according to the World Resources Institute, which updated its analysis on Monday with newly released satellite mapping showing intact forest landscapes shrank by 195 million hectares between 2000 and 2025, an area the size of Mexico.
Written by researchers Michelle Sims, Peter Potapov, Svetlana Turubanova, and Elizabeth Goldman, the analysis reads a quarter-century dataset compiled by a mapping team spanning the institute, the University of Maryland, and Greenpeace International. It shows the loss speeding up, from 7.1 million hectares a year through 2013 to 9.4 million hectares a year since 2014.
Between 2020 and 2025, fire drove 39.9 per cent of the reduction in intact forest area, close to double the 21.2 per cent it accounted for from 2000 to 2013, with the sharpest increases recorded in South and North America. Timber harvesting has fallen to second on 20.3 per cent, split between selective harvesting at 14.2 per cent and clear-cut harvesting at 6.1 per cent, while mining, drilling, and exploration climbed from 12.1 to 18.8 per cent.
“Intact forest landscapes are unique and irreplaceable,” the researchers write, warning that once these systems are broken apart, the biodiversity they hold is extremely difficult to restore. Unlike a harvested plantation block, an intact landscape cannot be replanted back into existence, and the mapping counts any patch that loses its integrity as gone for good.
Those fires are not starting deep inside these forests but along their frayed edges, where roads, farms, and mines have pushed in, making ignition far more likely, while hotter, drier conditions let the flames burn farther once they catch. Researchers count only blazes spreading from that human-altered fringe as a cause of loss, treating fire deep inside untouched forest as a natural disturbance.
Regionally, tropical South America is losing the most at 3.17 million hectares a year since 2020, followed by boreal North America on 1.87 million and boreal Eurasia on 1.55 million, where oil and gas infrastructure has opened access routes into forests that were previously too expensive to reach. Each of those three rates has climbed since the 2000 to 2013 period.
Just four of the dataset’s regions saw their loss rate fall, among them the Australian region, down from 210,000 hectares a year through 2013 to 20,000 since 2020, and Southeast Asia, where it halved to 380,000 hectares. Elsewhere, it climbed across the other five.
Canada, Russia, and Brazil, between them, still hold more than 65 per cent of what remains, and the same three countries have lost the most, led by Russia’s 53 million hectares, then Brazil’s 33 million and Canada’s 29 million. Ten countries account for nearly 90 per cent of all the intact forests left standing.
Romania has lost every hectare of intact forest it held in 2000, and Paraguay has lost 81 per cent, while Chile, Colombia, Finland, New Zealand, Sweden, and Venezuela each kept a million hectares or more and shed under 5 per cent.
The data itself was built by unpaid volunteers and carried no direct funding from any organisation or donor, according to Greenpeace International’s Global Mapping Hub. That same team has tracked the world’s intact forests since the first global map two decades ago.
What is disappearing is also among the planet’s hardest-working carbon stores, with the forests inside these landscapes taking up a net 1.62 billion tonnes of carbon dioxide equivalent a year, more than 30 per cent of the sink provided by all the world’s forests combined. Boreal forests make up 38 per cent of what remains, holding vast stores of soil carbon and shielding the permafrost beneath them.
Only 37 per cent of what remains has any legal protection, even though loss within strictly protected areas has been less than half that outside them, while nearly 60 per cent of the world’s intact forest sits on land held or used by Indigenous peoples. The researchers press for more of it to be locked in, through protected-area status, secure Indigenous land tenure, and finance that rewards countries for keeping forests standing.
It comes as the wider tree-cover record from the same platform showed fire overtaking agriculture as the leading cause of tropical forest loss last year, with boreal Russia and Canada burning in the same seasons as the Amazon. On the numbers the mapping team has now published, the world’s intact forests have shrunk by 15 per cent since 2000, up from the 12 per cent recorded when the map last ran to 2020, and every hectare that crosses the line is counted as gone for good.
