Underground peat fires surge in Indonesia amid drought and El Niño
Indonesia's peat fires are intensifying early in the 2026 fire season due to severe drought and a strengthening El Niño, drying out wetlands that can smolder underground for months. These fires release significantly more fine particulate matter and pollutants than typical forest fires, and thick smoke makes them hard for satellites to detect. The situation raises concerns about a potential repeat of the devastating 2015 fire season.
Peat fires differ from standard blazes by burning slowly through dried wetland soils, making them notoriously hard to extinguish. Their emissions are uniquely severe, releasing triple the fine particles, five times the sulfur dioxide, and double the methane and carbon monoxide of typical tropical forest fires. Indonesia holds roughly 36 percent of the world's tropical peatlands, making it especially vulnerable.
This year's early surge coincides with a strengthening El Niño and a positive Indian Ocean Dipole, which have left about 90 percent of the country with little or no rainfall. By early September, roughly a month into the season, emissions already reached about 10 percent of the total released during the catastrophic 2015 event. Thick smoke also obscures satellite sensors, complicating detection of these underground blazes.
The intensifying peat fires could expose millions across Southeast Asia to prolonged hazardous haze, potentially triggering respiratory illnesses and disrupting transportation and education. Because these underground blazes emit substantial greenhouse gases, they may also contribute to regional climate feedback loops. If the season mirrors 2015, the economic and health burdens on local communities could be severe, while international efforts to monitor and mitigate the smoke may face significant logistical challenges.