Wildfires in Indonesia are the most intense in 11 years, burning through forests and peatland on both Borneo and Sumatra
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Fire emissions from Indonesia are currently the highest in the world, as vast wildfires continue to burn through forests and peatlands on Borneo and Sumatra, data from Fire Emissions Watch has revealed.
A forest fire on Sumatra this week (13 October) has destroyed nearly 300 homes and caused hundreds of people to evacuate. Earlier this week, eight orangutans – including three mothers with their babies and two adolescent males – had to be relocated to a protected forest by car and boat, with 46 of the primates rescued since August.
All three orangutan species are critically endangered, and fewer than 130,000 remain in the wild.
Animals such as sivered langurs, long-tailed macaques and proboscis monkeys have also been found dead in blazes in Indonesia.
Between 1 September and 7 September, fire emissions from Indonesia reached 19.7 million metric tons – comprising more than one-third of the global total, according to the data. Russia is currently experiencing the second-highest fire emissions, followed by Brazil, Angola and the Democratic Republic of the Congo.
As one of the world’s most fire-prone countries, Indonesia’s wildfires are worsened by ‘super El-Niño’ weather conditions that drive temperatures up and increase the occurrence of droughts. While El Niño ‘does not necessarily create every fire’, it ‘greatly intensifies existing fires and allows them to spread more easily,’ said Indonesia country program director at the Centre for International Forestry Research Herry Purnomo.
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‘We do expect to see some fires across the region at this time of year, but with El Niño, it clearly just gives a big enhancement to them,’ said senior scientist at the Copernicus Atmosphere Monitoring Service Mark Parrington.
‘It’s much drier, it’s hotter, and when there’s ignition, these fires burn in a far more extreme way.’
In particular, Borneo’s fires are of particular concern to scientists as they are occurring in peatlands – valuable reservoirs for ancient carbon. When these burn, they risk releasing millions of tonnes of gases such as carbon dioxide, carbon monoxide and methane into the atmosphere.
‘Peatlands are incredibly effective carbon stores because their waterlogged conditions slow decomposition, allowing carbon to accumulate underground for thousands of years,’ said peatland researcher at Indonesian conservation NGO Yayasan Konservasi Alam Nusantara (YKAN) Dr Nisa Novita.
‘But this also means they can become a ‘carbon bomb’ when they are drained or burned, because that carbon can be rapidly released into the atmosphere.’
Fighting peat fires also requires vast swathes of water that saturate the ground. Even then, the fire could appear once more due to ‘invisible fuel’ buried in the peat swamp. To try to curb the fires, authorities have deployed more than 50 aircraft to artificially simulate rain in a process known as cloud seeding, as well as water-bombing operations.
Emissions in Indonesia were 273 per cent higher than the seasonal average, with fire emissions more than ten times larger than the Russian level. The highest concentrations of emissions were located in Kalimantan in Borneo and eastern parts of Sumatra.
Authorities have said fires in Indonesia could continue until El Niño’s peak in November.
The health risks of wildfire emissions
The air quality index in the city of Pontianak in West Kalimantan was recorded as 394 on Wednesday, far above the threshold of hazardous (set at 300). Between July and August, more than 50,000 cases of respiratory infections were recorded in Indonesia, linked to land and forest fires. More than 12,000 cases were in children under the age of five.
‘They’re breathing in carbon monoxide, which is toxic, and they’re breathing in the very finely divided particulate matter… [which] can pass through the alveoli in the lungs into the bloodstream and cause further problems elsewhere in the body, including issues with the heart,’ said professor at the University of Leicester’s school of geology and the environment Susan Page.
‘Living in this kind of pollution cloud is extremely unhealthy.’
The health impacts of wildfire pollution are also being felt in other countries. Malaysia’s health ministry has reported a 259 per cent rise in reported asthma cases, according to local media.
Air pollution in western Singapore on 14 October reached ‘very high’, the nation’s highest level. PM2.5 levels in the nation were recorded at 288 micrograms per cubic meter, far exceeding the WHO’s annual average exposure recommendation of just five micrograms. Singapore has also begun to distribute N95 masks to certain residents.
Meanwhile in East Timor, schools have announced they will shut nationwide for three days from Thursday 15 October. Such closures were necessary ‘as a preventive measure to protect the health of students, teachers and other members of the educational community, given current air quality conditions’, said the government.
Are they expected to get worse?
Parrington warned that emissions are expected to increase, as this marks just the beginning of the Indonesian wildfire season.
From January to July 2026, fires in Indonesia burned around 202,000 hectares (780 square miles) of land. In reality, this figure could be higher, as peat fires burning at low temperatures or underground may evade detection by sensors deployed by Fire Emissions Watch.
‘In two months we’ll know how extreme this year has been, but the early indications are that it is at pace, if not slightly above those previous El Niño years,’ Parrington continued.
Previously, a super El Niño in Indonesia in 2015 led to devastating fires, destroying around 2.6 million hectares and costing Indonesia around $28billion in damages. The fires may have also led to 100,000 premature deaths across Malaysia, Singapore and Indonesia.
