Indonesia is home to the world’s third-largest tropical forest, in which over 100,000 individual fires have been burning in recent months, primarily across the islands of Borneo and Sumatra. Consequently, up to 1.74 billion tonnes of CO2-equivalent had been released between the start of August (when the fires began burning) and the middle of November, making Indonesia one of the highest emitters of greenhouse gases in 2015, with daily emissions exceeding the entire US economic output.

‘The present-day peat fire dynamic of insular Southeast Asia is the consequence of what might be described as a “perfect storm” of events that provide the key ingredients for fire activity, namely an abundance both of fuel and of ignition sources,’ says Susan Page, professor in the Department of Geography at the University of Leicester.

Page states that over the last two decades, the region has experienced some of the highest rates of forest loss and disturbance anywhere in the tropics, with a particularly high loss rate for peat swamp forest. This is largely, she claims, a result of conversion to large-scale palm oil and pulpwood plantations – these plantations on peat increased in area by 12 per cent annually between 2007 and 2010. ‘The advent of these monoculture plantations has seen landscape-scale forest clearance and peat drainage but also widespread use of fire as a cheap, fast and effective means to clear large areas of forest debris and regrowth,’ she says.

In the past, small-scale use of fire posed limited risk of large-scale damage, but degradation and drainage of the peat swamps has converted a once fire-resistant landscape into a fire-prone one, in which there is abundant fuel for smouldering ground fires. Page stresses that the Indonesian peatlands store about 57 billion tonnes of carbon, which, if released by burning, could convert to as much as 210 billion tonnes of CO2.

This article was published in the December 2015 edition of Geographical magazine.