Borneo forest fires spike again: Why El Niño isn't the sole culprit

Forest and land fires across Indonesia have intensified once more, alarming residents and causing concern in neighboring nations. Thick smoke blankets residential areas and drifts into neighboring countries, prompting questions about the root causes. While El Niño conditions undoubtedly heighten the risk, a deeper investigation reveals that human activities play a pivotal role in transforming parts of the landscape into highly flammable environments.

Industrial plantations, including pulpwood and oil palm plantations, have led to the irreversible loss of natural water retention capacity in the Borneo ecosystem. Satellite data from NASA's Fire Information for Resource Management System (FIRMS) reveals a significant surge in fire activity across Kalimantan (Borneo) during mid-August, with MODIS and VIIRS satellite instruments detecting numerous thermal anomaly pixels.

West Kalimantan experienced the highest cumulative fire detections, with 82,728 active pixels at nominal-to-high confidence levels recorded between August 1–18, 2026. This is followed by Central Kalimantan, East Kalimantan, South Kalimantan, and North Kalimantan, each contributing substantially to the overall fire activity.

The World Bank estimates the economic losses from past severe fire seasons, such as 1997-1998, 2015, and 2019, to be in the billions of dollars, amounting to nearly 2% of Indonesia's GDP during those periods. These devastating fires underscore the need to recognize that fire events are not merely natural disasters; they are exacerbated by the vulnerability of the landscape, largely driven by human-induced factors.

Soil plays a critical role in maintaining water storage capabilities, and the degradation of soil structure, organic matter, and vegetation cover due to deforestation and plantation expansion amplifies the risk of fires. Peatlands, which cover 4.5 million hectares of Kalimantan, are particularly susceptible to fire due to disrupted water tables and drainage systems constructed for plantation purposes. These practices hasten soil drying and degradation, making peatlands more prone to fires, especially during El Niño events.

Addressing the recurring fire crisis requires a multi-faceted approach that combines immediate firefighting efforts, strict law enforcement against illegal fires, and long-term prevention strategies. Critical actions include halting further conversion of peatlands, restoring degraded peatlands to maintain water levels and vegetation cover, and implementing sustainable land management practices to prevent soil degradation and fire recurrence.