Tropical Forest Fires: When Nature and Deforestation Combine to Create a Global Crisis

Tropical rainforests are among the least fire-adapted ecosystems on Earth. Their extraordinary humidity — sustained by the moisture recycled through millions of trees — has historically protected them from fire. Lightning strikes in tropical forests rarely ignite lasting blazes; the air is too wet, the vegetation too damp. But deforestation, climate change, and deliberate burning have transformed this natural fire resistance. Tropical forest fires are now one of the major drivers of forest loss worldwide — and a significant source of carbon emissions that was barely on the radar of climate scientists two decades ago.

Why Tropical Forests Are Burning

The overwhelming majority of tropical forest fires — approximately 95% — are ignited by humans, either deliberately or accidentally. In the Amazon and Congo Basin, fire is routinely used to clear deforested land for agriculture — burning felled trees and brush to create pasture or cropland. These fires frequently escape their intended boundaries, particularly during drought years, spreading into surrounding intact forest. In Borneo and Sumatra, drainage of peatlands for oil palm cultivation creates conditions where peat fires can burn for months, releasing carbon stored over thousands of years.

The Edge Effect — How Fragmentation Increases Fire Risk

Intact primary tropical forest is largely self-protecting against fire. Its dense canopy keeps the understorey humid, its deep root systems access water even during drought, and its closed structure limits wind penetration that would dry vegetation. But at forest edges — created by roads, clearings, and deforestation — conditions are fundamentally different. Edge forest is exposed to drying winds, receives more direct sunlight, and has a more open structure. Research has found that fragmented forest is approximately 8 times more fire-prone than continuous primary forest — creating a positive feedback loop in which deforestation increases fire risk, and fires increase deforestation.