Fuels made from sustainable organic sources such as palm oil could create more greenhouse gas emissions than fossil fuels, according to a new studies reported by New Scientist.
There has been a big emphasis on biofuels in recent years as countries cast about for ways to reduce emissions, creating a new market for biofuel sources such as corn, palm oil and sugar cane.
One study, by an environmental research group called The Nature Conservancy, has found that the emissions generated when land is cleared to grow biofuels, and then when the crop roots decay after harvest, are greater than those saved by avoiding fossil fuels.
For example, the researchers say, if 10,000 square metres of Brazilian rainforest is cleared to make way for soya beans – which are used to make biodiesel – over 700,000 kilograms of carbon dioxide is released.
The saving generated by the resulting biodiesel will not cancel that out for around 300 years. In the case of peat land rainforest in Indonesia, which is being cleared to grow palm oil, the debt will take over 400 years to repay, the scientists have found.