El Niño Drove Indonesia's 2026 Wildfires, Scientists Find

In short: El Niño dried the landscape, and climate change loaded the dice.

Why did the fires spread so far?

Weather alone did not produce the disaster. The researchers flagged three decades of landscape change as a major contributor: deforestation and peatland drainage for agriculture, mining and logging.

Peatlands are waterlogged soils rich in partially decayed vegetation. When drained, they dry out, become flammable and can burn underground for months.

"Indonesia's landscapes have changed dramatically over the last 30 years, with extensive peatland drainage and deforestation creating landscapes that can be extremely vulnerable to ignition," said meteorologist Pramudhian Firdaus of the FLARE Wildfire Research group, who contributed to the analysis.

What did the haze cost in public health?

Smoke from the fires made hundreds of thousands of people ill in Indonesia, where residents breathed toxic haze for weeks. Neighboring countries also registered dangerously high air pollution levels, exposing many more people beyond the archipelago's borders.

The health toll mirrors the 2015 Indonesian fire crisis, when peat smoke sickened people across Singapore, Malaysia and Indonesia. This year's event, while severe, awaits a full epidemiological count.

How solid are the numbers?

The 2.88-million-hectare figure comes from the Nusantara Atlas, a deforestation monitoring platform, and it grew by nearly one million hectares (2.5 million acres) in a single month — a measure of how fast the fire front moved.

The Indonesian government has neither confirmed nor rejected the estimate and has released no official figure of its own for area burned since July. That gap leaves independent monitors as the primary source for the burn tally.

Indonesia experiences fires every dry season, but this year's blazes have been particularly severe.

What would reduce future risk?

Firdaus put the policy prescription plainly: "These findings show how both emissions reductions and sustained forest and peatland protection are important in reducing future risk."

That dual framing is the study's practical takeaway for practitioners in land management and climate policy. Cutting fossil fuel emissions addresses the warming multiplier; protecting and rewetting forests and peatlands addresses the fuel supply.

Neither measure alone, the findings suggest, would have prevented this season's outcome.

Attribution science is young and these results are preliminary in the sense that they await peer review, as is standard for WWA's rapid analyses. Even with that caveat, the direction is unambiguous: a natural climate pattern, amplified by warming and staged on drained land, produced one of Indonesia's worst fire seasons on record.