JAKARTA, November 13, 2026 — Indonesia’s devastating 2026 wildfire season has exposed how natural climate cycles, human-caused global warming and decades of land-use pressure can combine to create exceptionally dangerous fire conditions. A new attribution study released by World Weather Attribution (WWA) on November 12 found that climate change substantially intensified the hot, dry weather that helped fires spread across western Indonesia between August and October.

The findings arrive as satellite monitoring data show that fires affected approximately 2.88 million hectares of Indonesian land between January and October 2026. The scale of the damage, reported by Reuters on Friday, has renewed scrutiny of peatland drainage, forest conversion and the safeguards used by plantation operators and financial institutions.

Satellite image showing smoke plumes from fires across Borneo on September 1, 2026
Smoke from fires scattered across Borneo, captured by NASA’s Aqua satellite on September 1, 2026. Image: NASA Earth Observatory / Lauren Dauphin; public domain as U.S. government work. NASA image and background.

What The New Climate Attribution Study Found

The WWA assessment examined the unusually hot and dry conditions recorded during the peak fire period. Its central conclusion is that El Niño was a major driver of the rainfall deficit, while human-induced climate change added substantial heat and made the conditions that favour fires more likely.

Researchers estimated that climate change raised seasonal temperatures during the August-to-October period by approximately 1.6°C. The ongoing El Niño added a further estimated 0.3°C. The analysis also found that short periods of extremely hot, dry weather of the kind observed during the fire season have become about three times more likely because of human-caused warming. El Niño increased the likelihood of those conditions by roughly five times.

The distinction matters. El Niño is a naturally occurring climate pattern that changes ocean temperatures and atmospheric circulation, often reducing rainfall in parts of Indonesia. The researchers’ findings indicate that global warming is intensifying the heat against which those natural dry spells unfold. In practical terms, the same drought conditions can now produce more severe fire weather than they would have in a cooler climate.

The study says El Niño reduced seasonal rainfall by about half during the relevant period. It also notes that climate change contributed to the severity of the hot, dry conditions, although the researchers were more confident in their temperature and fire-weather findings than in the rainfall attribution.

Nearly 2.9 Million Hectares Affected

Reuters reported on November 13 that monitoring data from Nusantara Atlas recorded approximately 2.88 million hectares of land affected by fires from January to October. The figure places the 2026 season among Indonesia’s most damaging in recent years and represents a substantial increase from the monitoring update issued in September.

The World Weather Attribution report separately described around 1.9 million hectares as burned by September. These figures refer to different reporting cut-off dates and should not be read as competing estimates of the same period. The later January-to-October assessment captures the subsequent expansion of the affected area.

Fires were concentrated in parts of Sumatra and Kalimantan, where drained peatlands and degraded forest can remain combustible for extended periods. Peat fires are particularly difficult to extinguish because flames can move below the surface, smoulder underground and re-emerge after surface fires appear to have been controlled.

Thick smoke haze obscuring the sky above a residential area in Kalimantan, Indonesia
Smoke haze over a residential area in Kalimantan in August 2026. Photo: PadukaYash / Wikimedia Commons, CC BY 4.0. Image source · Licence.

Peatland Drainage And Land Conversion Increase The Risk

Scientists say the climate conditions alone do not explain the scale of the disaster. Indonesia’s landscape has also been altered by deforestation, plantation expansion, logging and the drainage of peatlands. When peat soils lose moisture, they become more vulnerable to ignition and can sustain fires that are difficult to reach with conventional firefighting equipment.

The WWA assessment identifies peatland restoration, forest protection and better land management as central parts of reducing future fire risk. Measures include blocking drainage canals, keeping water tables higher, limiting further forest conversion and encouraging agricultural practices that do not depend on burning vegetation.

A separate Reuters report on November 13, based on research by Rainforest Action Network and Nusantara Atlas, examined fire damage on land linked to publicly listed Indonesian companies. The researchers identified substantial burned areas on several concessions but did not establish who ignited the fires. The distinction is important: evidence that a fire occurred on a concession is not, by itself, proof that the company or its workers started it.

Smoke Pollution Has Become A Regional Health Concern

The effects have extended beyond the locations where the fires started. Smoke and haze have affected communities across Indonesia and neighbouring parts of Southeast Asia, including Malaysia, Singapore and Timor-Leste. The WWA report estimates that around 12.5 million people were exposed to haze across the affected region.

Indonesian authorities had reported more than 400,000 respiratory infections associated with the fire crisis by the time of the WWA assessment. Children, older people, pregnant women and people with asthma or other respiratory and cardiovascular conditions face particular risks from prolonged exposure to fine particles in wildfire smoke.

Smoke pollution can aggravate existing breathing problems and may contribute to more serious health effects. Public-health responses therefore need to go beyond advising people to stay indoors. Reliable air-quality monitoring, timely public alerts, access to clean indoor spaces and protection for outdoor workers are also important during severe haze episodes.

Forest-fire haze covering the landscape in Berau, Kalimantan, Indonesia
Forest-fire haze in Berau, Kalimantan, photographed on August 20, 2026. Photo: Mesa Kala / Wikimedia Commons, CC BY 4.0. Image source · Licence.

Why The Findings Matter Beyond Indonesia

Indonesia’s forests and peatlands are important carbon stores, while smoke from large fires can travel across national borders. The crisis therefore connects local land management with regional public health, climate policy, biodiversity and international supply chains.

For businesses, the scale of the fires raises questions about supply-chain transparency and the environmental risks attached to commodities produced in fire-prone landscapes. Investors and lenders are also facing pressure to examine whether companies have credible fire-prevention systems, traceable suppliers and effective procedures for protecting peatlands and forests.

The research does not mean every fire was directly caused by climate change, nor does it identify the person or organisation responsible for each ignition. Rather, it explains how warming and El Niño increased the probability and intensity of the conditions in which fires could spread. Local land management and prevention remain decisive factors in limiting the damage.

What Indonesia Can Do Before The Next Fire Season

The WWA researchers argue that the predictability of El Niño creates an opportunity for earlier preparation. Authorities can use seasonal forecasts to identify high-risk periods, strengthen fire patrols, prepare firefighting teams and equipment, and issue health warnings before haze becomes widespread.

Longer-term prevention requires restoring damaged peatlands, protecting remaining forests, reducing drainage and improving enforcement against illegal burning. Monitoring systems should be transparent enough to identify emerging fires quickly and allow independent scrutiny of land-use practices.

Regional cooperation also matters. Smoke does not stop at national borders, so Indonesia and neighbouring governments need shared air-quality information, coordinated public-health messages and practical arrangements for responding to cross-border haze.

HeadlinesXtra Analysis

The 2026 fires illustrate why treating El Niño as the sole explanation would be incomplete. The natural climate pattern helped create a rainfall deficit, but the WWA analysis shows that human-caused warming added significant heat and increased the likelihood of dangerous fire weather. At the same time, degraded peatlands and forest conversion made parts of the landscape more vulnerable when the dry conditions arrived.

The policy lesson is that emergency firefighting and long-term prevention must be treated as connected responsibilities. Aircraft, personnel and water-bombing operations are essential during an active crisis, but they cannot substitute for keeping peatlands wet, protecting forests and reducing the incentives for land clearing through fire.

Indonesia’s challenge is also one of accountability. Publicly available satellite data, clear concession boundaries, independent monitoring and transparent investigations can help distinguish accidental fires, illegal burning and other causes without making unsupported accusations. Financial institutions and commodity buyers can reinforce prevention by demanding credible evidence that suppliers are managing fire risk.

The next fire season is not inevitable in its severity. Forecasting can provide time to prepare, and restoration can reduce the amount of vulnerable land. But the findings suggest that prevention must begin well before smoke appears on satellite images. Without stronger land protection and sustained climate action, future El Niño events are likely to test Indonesia’s fire-response capacity again.

Sources And Further Reading

Image Credits And Licences

  • NASA satellite image of smoke over Borneo — NASA Earth Observatory / Lauren Dauphin, September 1, 2026; public domain as U.S. government work. Source.
  • Kalimantan smoke haze — PadukaYash, August 20, 2026; Wikimedia Commons, CC BY 4.0. Source file.
  • Forest-fire haze in Berau — Mesa Kala, August 20, 2026; Wikimedia Commons, CC BY 4.0. Source file.