The year 2015 will be the hottest on record. You’ve probably heard that by now. What does not receive media attention is that 2015 is likely to also bring a dramatic peaking record in global anthropogenic CO2 emissions, if we add ‘land use change’ [a nice phrase for slash & burn] to global fossil fuel emissions [to the atmosphere of course there's little difference]. Again all this adds to a very dramatic background to the Paris climate negotiations at the end of this year.
The above image was captured by a NASA satellite last week and shows large parts of South East Asia (Borneo, Sumatra, Singapore) covered in a brown haze of soot and other air pollution derived from Indonesian forest fires, which has now also reached Thailand. These slash & burn forest fires are provoked by an El Niño-induced drought that is set to continue over the months ahead. In its intensity the end-2015 Super El Niño resembles that of end-1997, when uncontrolled forest fires over Borneo and Sumatra added billions of tonnes of extra CO2 to the atmosphere.
Large parts of Borneo and Sumatra are (still) covered by tropical peat land rainforests. These peat forests lie on relatively flat ground – sought after for palm oil plantations. Whenever prolonged drought strikes ‘forest clearing’ becomes an easy job: Just light a match.
The fact that these Indonesian rainforests have thick peat layers as soil actually makes them impressive carbon stores. Problem with the forest fires is that not only the live vegetation burns, but also the peaty soils smolder, sometimes for months on end, releasing far larger amounts of CO2 to the atmosphere than the initial forest fire emitted.
Burning peat soils are the carbon problem
In 2002 a research group led by the University of Leicester published a study in Nature of the carbon emissions of the 1997 Indonesian forest fires. Judging by satellite and field measurements they concluded the burning peat soils released more carbon than the burning vegetation – about 4 to 5 times as much.
Altogether during the end-1997 El Niño these researchers estimated Indonesian forest fires emitted about 0.81 and 2.57 gigatonnes of carbon. As one tonne of carbon equates to 3.67 tonnes of CO2, the 1997 Indonesian peat forest fires emitted between 2.97 and 9.43 billion tonnes of CO2.
If you would relate that to the global CO2 emissions from fossil fuel use of 2014, which amounted to 32.3 billion tonnes – Indonesian forest fires during the current Super El Niño have the potential to add 10-29% of extra CO2 to the world’s fossil fuel-related emissions.
It could be better – it could also be worse
Indeed, the current Indonesian forest fires could develop differently under the current El Niño than they did during the 1997 El Niño. Firefighters could be more effective and things could be better. Land hunger could be larger still and things could be worse.
One thing to add is that this year it is not just Borneo that is experiencing a drought. There is also one developing in the world’s largest rainforest: the Amazon. And as we recall from a couple of years ago, Amazon droughts can also release massive amounts of CO2.
© Rolf Schuttenhelm | www.bitsofscience.org