Indonesia on track to have the worst fire season since 1997

September 24 image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Thick gray smoke from fires hovers over the islands of Sumatra (left) and Kalimantan (right) and has triggered air quality alerts and health warnings in Indonesia and neighboring countries. Visibility has plummeted.

This story was written by staff from the International Research Institute for Climate and Society and NASA Goddard Institute for Space Studies. Media can contact Francesco Fiondella.

Much of western Indonesia is currently burning, producing enormous amounts of smoke-haze, and disrupting large parts of society in the region. Scientists are suggesting that this is not ‘normal’ seasonal burning and could end up ranking among the worst on record. This is one of the first severe impacts of the strong El Niño that has been developing over the last year.

“The El Niño is now in full swing and is one of the largest El Niño events of the last 50 years,” says Tony Barnston, who is the chief forecaster at Columbia University’s International Research Institute for Climate and Society.

Fires in Indonesia are larger and more numerous this year than in previous years, according to Guido van der Werf of the Vrije Universiteit Amsterdam and Robert Field of the NASA Goddard Institute for Space Studies. “NASA fire count and pollution measurements from satellites show that we are on a track above any other year since 2001 — when observations became available — and we are only halfway through the fire season. Longer-term ground reports suggest that the current event is falling somewhere between the severe episode in 2006 and the haze disaster of 1997.”

These charts show visibility levels (left) and the number of fires detected by satellites (right) over Indonesia for 2015 compared to previous years. Courtesy of G. van der Werf

There will likely be little relief through October and possibly into early November, according the most recent seasonal climate forecasts issued by IRI. These forecasts show a very strong chance that most of western Indonesia will see below-normal rainfall for the remainder of the dry season. Allan Spessa of the Open University in the United Kingdom has shown that these types of forecasts can, on average, be reliable predictors of severe fire years.

“Critically, the strong El Niño translates into a delayed onset of the rainy season,” says Andrew Robertson, who heads IRI’s Climate Group. “Our research shows that the severity of the fire season is related to the onset date of the rainy season. If it’s delayed, fires will burn longer and intensify the environmental and social impacts.”

This is the latest rainfall forecast for the October-November season for Indonesia. As the map shows, there’s at least a 70% likelihood (brown areas) that much of Indonesia will receive below-average rainfall — which doesn’t bode well for fire management efforts. International Research Institute for Climate and Society.
Central Kalimantan, Indonesia. Francesco Fiondella

Fire is used as a means of clearing land for agriculture in Kalimantan and other parts of Indonesia.

“Most burning starts on idle already-cleared peatlands and escapes underground into an endless source of fuel. The fires are often in remote locations, which, along with being below the surface, makes them difficult to extinguish,” according to David Gaveau of the Center for International Forestry Research, based in Jakarta.

The smoke contributes to enhanced concentrations of multiple pollutants, most notably particulate matter and ozone, which have a significant negative impact on air quality and people’s health. Miriam Marlier, of the University of California in Los Angeles and Columbia University, has studied how these fires affect regional mortality. “These fires not only impact Indonesia but also conditions nearby in Singapore and Malaysia.”

According to her previous work, about 11,000 adults in the region died prematurely in 1997 due to cardiovascular diseases related to poor air quality attributable to fires.

“…the strong El Niño translates into a delayed onset of the rainy season…If it’s delayed, fires will burn longer and intensify the environmental and social impacts.

This burning is what makes Indonesia such a disproportionately large greenhouse gas emitter relative to the size of its economy. Van der Werf showed that fire emissions in 1997, which released greenhouse gases equivalent to 4 billion tons of carbon dioxide, were roughly comparable to a year’s worth of current fossil fuel emissions in the European Union.

“We will know in a few months what this year’s fires have emitted, but that it is a substantial amount is already certain,” says van der Werf.

Follow @climatesociety and @robertfield for updates on the situation.