A new study finds that the creation of palm oil plantations is releasing ancient sources of carbon dioxide back into the atmosphere.
The new findings, published in the journal Nature, cast doubt on claims that growing palm oil trees for biofuels could help reduce greenhouse gas emissions.
A team of international researchers examined how the deforestation of peat-swamps in Malaysia, to make way for oil palm trees, is releasing carbon that has been deposited deep in the soil for thousands of years.
For their study, the research team measured the water leaching from channels in palm oil plantations in the Malaysian peninsula that were originally Peatland Swamp Forest. They found sources of carbon stored deep in the soil, which then breaks down and dissolves into the nearby watercourses as a result of deforestation. When the research team took samples to measure the age of the carbon, they found that the palm oil plantations contained prehistoric carbon.
Microbes attack the carbon and produce carbon dioxide, which is the primary greenhouse gas responsible for increase in global temperatures.
"We have known for some time that in South East Asia, oil palm plantations were a major threat to biodiversity, including the habitat for orangutans, and that the drainage could release huge amounts of carbon dioxide during the fires seen there in recent years," study author Chris Freeman, an environmental scientist at the University of Bangor in Wales, said in a statement.
"But this discovery of a "hidden" new source of problems in the waters draining these peatlands is a reminder that these fragile ecosystems really are in need of conservation," he added.
More than 80 percent of palm oil trees is grown in Indonesia and Malaysia, according to Reuters. Biofuel is seen as a low-carbon alternative to fossil fuels for transportation. However, there had been claims that palm oil is not environmentally sustainable. This new study adds weight to those claims, suggesting that biofuels from palm oil trees could accelerate the effects of climate change.
"Our results are yet another reminder that when we disturb intact peat swamps and convert them to industrial biofuel plantations, we risk adding to the very problem that we are trying to solve," said Freeman.