Indonesia’s peat fires are smoldering underground as El Niño and drought deepen the 2026 season

Peatland fires in Indonesia have begun earlier and more intensely in 2026. Unlike fast-moving crown fires, peat fires burn slowly through carbon-rich wetland soils and large peat deposits. When peat dries during drought, flames can move below the surface and smolder for months.

Peat fires produce more pollution per hectare than typical tropical forest fires. One estimate cited in the reporting attributes roughly three times more fine particulate matter to peat fires, along with about five times more sulfur dioxide, three times more organic carbon, and roughly double the methane and carbon monoxide. Those pollutants worsen air quality locally and across Southeast Asia, and they add large, concentrated greenhouse-gas emissions.

NOAA assessed El Niño as present and strengthening in August 2026. The pattern commonly reduces rainfall over much of Indonesia. A positive Indian Ocean Dipole was also underway, combining to make the dry season drier across fire-prone regions. Indonesia's meteorological agency reported that around 90% of the country received little or no rainfall in early August, creating conditions that allow peat to dry enough to ignite.

Indonesia contains about 36% of the world's tropical peatlands. Historical strong El Niño years like 1997 and 2015 produced some of the worst peat-fire seasons on record. In 2015, fires emitted about 1.75 billion tons of greenhouse-gas equivalents. By September 2, 2026, the season had already released roughly 10% of the 2015 total after roughly a month of burning, signaling an escalation similar to 2015, according to Columbia University researcher Robert Field.

Satellites such as MODIS and VIIRS are primary tools for near-real-time fire monitoring and feed Indonesia's SiPongi platform. On August 31, 2026, SiPongi counted 946 hotspots. But remote sensing has important blind spots: thick smoke can block sensors, canopy cover can hide active smoldering, and underground peat fires can produce weak surface thermal anomalies. As ecologist Mark Cochrane noted, the most severe smoke events can paradoxically reduce satellite detections because the smoke obscures the view.

Duration and suppression challenges

Underground peat fires burn at relatively low temperatures and can persist until substantial rain returns. Field warned that once fires move into peat, "they just won't stop" and are likely to continue until October or November rains. Their low heat and depth make suppression and extinguishment difficult with conventional firefighting methods.

Public health impacts include severe haze episodes and respiratory problems across large populations. The high emission factors of peat fires mean these events also represent sharp, near-term pulses of greenhouse gases. Monitoring, ground access for suppression, and addressing land-use practices that expose peat to ignition remain central to how the season unfolds.