Slash and burn – a process to clear the ground for agriculture – is a common practice, undertaken in many countries across the globe. However this year in South East Asia, particularly Indonesia, the use of slash and burn has risen to an unprecedented high. Worryingly, this has resulted in the release of huge volumes of carbon on a daily basis. So, why has this year seen such large increases in carbon emissions?
One of the main reasons behind the historically high levels of emissions is the current, unusually long dry season, which has allowed the intentionally lit fires to smoulder for longer periods – prompting the release of more Carbon. The current extreme dry season can be attributed to the developing El Nino; a complex series of climatic changes, characterised by increased surface water temperatures, which occurs in the southern hemisphere.
Peat soils – of which around 400,400sq km are located within the tropics – are recognised as significant sources of sequestered Carbon, with estimations suggesting they store more than grasslands, forests and heather combined. However in places such as Indonesia, peat soils are routinely destroyed in order to provide room for the growth of high value ‘cash crops’, particularly species required for the production of palm oil. The areas of peat land located in Indonesia, when burned, produce more smoke than other types of fire and can continue to burn for weeks or even months. As a result of slash and burn practices, these areas of peat – which store in the region of 100 billion tonnes of carbon – are estimated to produce daily emissions that are equivalent to the annual total of those produced in New York City!
In addition to the release of carbon, peat land fires have other lasting consequences. The province of South Sumatra, in Indonesia, is attributed with the majority of the emissions. The region is home to almost 8 million people – a figure comparable with the population of London – and the associated emissions of slash and burn can prompt the mass displacement of thousands of people from their homes. There is also evidence which indicates that there are a greater number of deaths as a result of the increased levels of air pollution. The smoke haze released from the slash and burn practice – which often spreads across the entire region of Malaysia and Indonesia and can be seen from space – has been linked to increased risks of respiratory disease, strokes, lung cancer and heart attacks. Consequently, the regional and national press must often warn inhabitants to stay indoors when there are high emission levels. It has been estimated by Greenpeace that, as a result of the haze, South East Asia experiences around 110,000 deaths due to pollution related illnesses.
In the last 100 years, the race to produce palm oil has meant that 90% of Indonesia’s rainforests have been cleared, prompting species extinction as well as the release of previously stored carbon. The environmental repercussions of slash and burn practices can be felt globally, with the particulates created from peat land burning affecting the way sunlight is absorbed by the atmosphere. Tropical peat land fires located within the state of Pahang have been extensively studied, resulting in the identification of released greenhouse gases, such as carbon dioxide, carbon monoxide and methane, which are known to have a negative effect on climate change. The severity of the fires have also had a political impact, prompting Joko Widodo, the Indonesian President, to deploy 10,000 troops to fight the spread of fires following his visit to South Sumatra last month. Furthermore, Singapore has also offered the use of their military aircraft to aid in the fight against manmade slash and burn fires – fires which have exceeded the recorded average emissions over the last decade, reaching a record high of 15 TgC per day.
The impact of peat fires on climate change will continue to exacerbate the precarious position we place our planet in, unless action is taken. Slash and burn practices not only release the previously stored carbon stocks, but they also cause a knock on effect to the human and animal populations living in Malaysia, Indonesia and Singapore. Additionally, if the effects of El Nino increase next year, conditions will continue to be exacerbated, meaning we can expect the same levels, if not worse, of carbon emissions next year.
Image: Wikimedia Commons