Forest fires on Borneo worsen air quality across South-East Asia
Satellite measurements and Indonesian weather data point to numerous fires during an exceptionally dry period.
In the Indonesian part of Borneo, Kalimantan, forest and peat fires are putting air quality under pressure. Drought, a strong El Niño and the vulnerability of peatlands are increasing the risk of new fires, according to Indonesian authorities.
Indonesia’s weather service BMKG called September a critical phase for forest and land fires. The service pointed to dry conditions, the influence of El Niño and the high number of so-called hotspots. These are satellite observations of thermal anomalies; they do not correspond to an exact measured fire area.
According to a BMKG overview up to and including 21 September, the highest number of registered hotspots was in Central Kalimantan: 5,283. West Kalimantan followed with 1,357, while hundreds of reports were also recorded in South and East Kalimantan. The measurements show the spatial distribution of fire activity, not automatically the severity of each individual fire.
NASA published a satellite image showing fire detections in Indonesia. The organisation warns that peat fires can continue to burn underground and are therefore difficult to extinguish. The smoke can also spread across provincial and national borders.
The consequences are not only ecological. Associated Press reported earlier this month that thick smoke in West Kalimantan disrupted flights and raised health concerns. Disruption was also reported in parts of Malaysia, Brunei and Singapore. The extent and duration of the smoke vary greatly according to location and wind direction.
The Indonesian government is conducting firefighting operations and warning against lighting open fires. At the same time, the precise cause of individual fires is often difficult to establish. Some fires may be linked to land use, while weather conditions determine how quickly fire spreads.
The current situation illustrates the difference between measurement and explanation. Satellites count heat points, meteorologists describe drought and El Niño, but only local investigation can establish who caused a fire and what damage occurred. For the region, it is above all the combination of smoke, vulnerable peatland and continuing drought that remains the risk.
One story, several perspectives
What is established
- There are many satellite-detected hotspots in Kalimantan.
- Dry conditions and El Niño increase the risk of fires.
- Smoke spreads across provinces and national borders.
Left
Arguments The government should protect peatlands more effectively, regulate land use more strictly and give greater weight to health damage than to short-term gains.
Values Environmental justice, public health and the protection of communities.
Consequences Stricter enforcement may limit agriculture and land exploitation, but it would reduce structural smoke and climate damage.
Centre
Arguments Effective policy combines firefighting, improved satellite monitoring, local cooperation and realistic rules for farmers and businesses.
Values Practicality, evidence and regional cooperation.
Consequences A combination of measures can limit damage without bringing the economy to a complete standstill, but it requires long-term funding.
Right
Arguments The emphasis should be on swift enforcement against those responsible and on Indonesia’s ability to manage its own land and economy.
Values National responsibility, property rights and order.
Consequences Targeted sanctions and firefighting can deliver faster results, but they cannot on their own solve drought and vulnerable peatland.
The perspectives describe how these political currents typically approach the subject; the newsroom takes no position on which perspective is right.
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The text distinguishes between satellite measurements, meteorological explanations and possible causes. The figures used and the regional consequences can be found in the official and independent sources cited.
- confirmed BMKG calls September 2026 a critical phase for forest and land fires. — This is stated in BMKG’s report of 7 September. source
- confirmed Up to and including 21 September, 5,283 hotspots had been registered in Central Kalimantan. — BMKG gives this figure in its weekly overview. source
- confirmed A hotspot is a satellite detection of a thermal anomaly and not a direct measure of fire area. — NASA describes the detections as pixels with thermal anomalies that may indicate fire. source
Editor's note
Hotspot figures, satellite observations and the meteorological context have been confirmed. The source data do not say that every thermal image represents a complete fire or that every fire was caused by human land use.Sources
More on this in Dutch media
- NOS — „borneo kalimantan”
- Het Parool — „borneo kalimantan”
- de Volkskrant — „borneo kalimantan”