Indonesia Haze Spreads as ASEAN Faces Regional Air Crisis

JAKARTA – Smoke from Indonesia’s forest and land fires is once again crossing national borders, worsening air quality across parts of Southeast Asia as the region faces hotter and drier conditions linked to a strengthening El Niño.

The ASEAN Specialised Meteorological Centre (ASMC) has warned that the risk of transboundary haze remains elevated. Dry conditions are expected to persist across parts of southern and central Borneo and southern Sumatra, while prevailing southeasterly and southerly winds could continue carrying smoke toward neighboring countries.

Data from the European Union’s Copernicus climate monitoring service, cited by Reuters, showed that Indonesian wildfires produced an estimated 19.7 million metric tons of CO? emissions between September 1 and 7. That accounted for more than one-third of global wildfire emissions during the period and was 273% above the seasonal average.

The regional impact has already become visible. Malaysia temporarily declared an emergency in Serian, Sarawak, after hazardous air pollution linked to smoke from fires on the Indonesian side of Borneo. The emergency was later lifted as air quality improved, although health concerns remained.

Singapore has also continued monitoring smoke drifting from Sumatra and Kalimantan. On September 10, one-hour PM2.5 readings reached 38–70 µg/m³, while the 24-hour Pollutant Standards Index stood between 73 and 104, ranging from moderate to unhealthy levels. Authorities warned that haze could persist as long as fires and dry weather continue.

The Philippines has also recorded elevated pollution levels. Environmental authorities in Koronadal reported 24-hour PM2.5 concentrations of 48 µg/m³ on September 1 and 46 µg/m³ on September 2, both exceeding the national limit and classified as very unhealthy. Officials linked the deterioration partly to transboundary haze from fires in Kalimantan.

Indonesia has meanwhile shifted more than 1.4 million students to remote learning because of hazardous air pollution in several provinces. Japan is also deploying three CH-47 Chinook helicopters to support Indonesia’s firefighting operations beginning September 12.

Malaysian Prime Minister Anwar Ibrahim has called for ASEAN to review and strengthen its mechanisms for tackling transboundary haze, arguing that the recurring crisis directly threatens public health, particularly children.

For ASEAN, the latest haze crisis is becoming another test of whether regional cooperation can keep pace with an environmental threat that ignores national borders.