If there were a superpredator among the fires, tropical peatlands Fires would be one of the main contenders. These fires, which burn in dry wetland soils, are slow burning, highly polluting and very difficult to extinguish because they burn at low temperatures and often burn underground through large peat deposits. By one estimate, peat fires generate three times more fine particles than other tropical forest fires, five times more sulfur dioxide, three times more organic carbon, and two times more methane and carbon monoxide.
Fire season was underway in Indonesia when the MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Aqua satellite captured this image on September 1, 2026. On the map to the right, each red dot represents a “fire detection.” A fire detection is a pixel where the sensor and an algorithm determined that there were thermal anomalies indicative of a fire. A single fire can generate multiple detections.
Peat fires are a recurring challenge in Indonesia, which is home to about 36 percent of the world’s tropical peatlands. When the archipelago’s peat landscapes are parched by drought, they have become relentless infernos on several occasions over the past three decades, with fires producing blankets of smoke for weeks and disrupting the daily lives of millions of people.
While fires occur in Indonesia every year, previous El Niño years (especially 1997 and 2015) produced the most extreme fires in recent decades. The weather pattern, assessed by NOAA as present and strengthening in August, typically leads to sharp precipitation reductions in Indonesia, particularly when combined with a positive phase of the Indian Ocean Dipole, which was also present.
“Indonesia is only about three weeks into the fire season, but we are seeing fire activity increase sharply, similar to 2015,” said Robert Field, a researcher at Columbia University who developed a tool called the Global Fire Weather Database that produces experimental fire weather forecasts in real time. “The strong El Niño is making the dry season drier in fire-prone parts of the country and exacerbating fires, just as we anticipated would happen,” he said. In 2015, after burning for more than three months, Indonesia’s fires released 1.75 billion tons of greenhouse gas equivalents, more than Japan emits in a year. As of September 2, the 2026 fires in Indonesia, which had burned for about a month, had released about 10 percent more than the 2015 fires.
As in 2015, Indonesia was in the midst of a severe and widespread drought in the summer of 2026. About 90 percent of the country received little or no rain in early August, according to data from Indonesia’s meteorological agency. Typically, there is too much moisture for fires to spread through underground peat deposits in Kalimantan, Sumatra and Papua, but they can do so in dry conditions. “Fires on the surface are less of a concern, but when fires get underground, they just don’t stop,” Field said. “They will continue to burn until the rains come in October or November.”
The Indonesian government uses NASA and NOAA observations from the MODIS and VIIRS sensors to track active fires in near real time. The SiPongi fire monitoring platform, based on MODIS and VIIRS of the Indonesian Ministry of Forests, for example, counted 946 hotspots on August 31, 2026.
However, it is difficult for MODIS and VIIRS to detect fires through clouds or dense smoke, within the understory or underground in peat deposits. When fires in Indonesia become more intense, the number of fires recorded by VIIRS or MODIS may actually decrease. “Paradoxically, the worst smoke events may be the most difficult to observe from space with MODIS and VIIRS,” said Mark Cochrane, an ecologist at the University of Maryland Center for Environmental Sciences who has conducted field research on peat fires in Indonesia for nearly a decade.
Large-scale construction of peat swamp drainage and irrigation canals in the 1990s, part of an effort to establish massive rice farms, contributed to the flammability of the current region by significantly lowering the water table in wetland areas, Cochrane said. He also noted that oil palm and other forest plantations are common in this region. However, after an unusually grim fire season in 2015, governments and other organizations have worked to damming some irrigation canals and restoring wetlands. There have also been renewed efforts to improve firefighting capacity and reduce the number of fires that people accidentally set.
“This year will be a real stress test for the measures that were implemented after 2015,” said Shi Jun Wee, a graduate student at the University of Maryland. Wee is working on a team partnered with NASA and MapBiomas to develop new algorithms and techniques to detect more understory fires than MODIS and VIIRS by taking advantage of shortwave infrared observations from the Landsat and Sentinel-2 satellites. As the fires progress, it plans to follow developments using NASA’s Worldview data navigator, FIRMS (Fire Information for Resource Management System), HLS (Harmonized Landsat and Sentinel-2) observations, and GFED (Global Fire Emissions Database).
In Indonesia and neighboring countries, smoke is already causing widespread disruption. Indonesian officials have warned that large sections of the population have been exposed to dangerous smoke. Some schools began switching to remote learning, nine national parks closed and several flights were delayed due to heavy smoke, according to news reports.
“People tend to focus on these fires during El Niño and then forget about them,” Cochrane said. “We need a sustained approach, even during the years when they are not so bad, to solve this,” he said. “These fires create a huge amount of emissions.”
NASA Earth Observatory image by Lauren Dauphin, using MODIS data from NASA LAUNCH EOSDIS and GIBS/worldview. Story by Adam Voiland.
- BMKG (2026, August 13) Analisis Dinamika Atmosfer Dasarian I Agustus 2026. Accessed September 2, 2026.
- Channel News Asia (2026, September 2) Indonesia temporarily closes 9 national parks after forest fires; prioritizes fighting fires in 6 provinces. Accessed September 2, 2026.
- The Conversation (August 23, 2026) Borneo wildfires on the rise again: why El Niño isn’t the only one to blame. Accessed September 2, 2026.
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- Kementerian Kehutanan Republik Indonesia (2026, August 31) Terbaru Karhutla Update: Hotspot Menurun, Penanganan Diperkuat. Accessed September 2, 2026.
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