Researchers at the University of Leeds and the World Land Trust have warned that growing biofuel crops to make eco-friendly car fuel could actually be harmful to the environment.
Large areas of land in the developing world are being converted to grow crops such as sugar cane and palm oil as part of the global rush to make biofuels which are widely thought to produce less carbon dioxide than conventional transport fuels.
But scientists at the University of Leeds and the World Land Trust have found that up to nine times as much carbon dioxide will be emitted using biofuels compared to conventional petrol and diesel because biofuel crops are typically grown on land which is burnt and reclaimed from tropical forests. The report concludes that protecting and restoring natural forests and grasslands is a much better way to reduce carbon dioxide emissions.
Study co-author Dominick Spracklen of the School of Earth and the Environment at the University of Leeds says: "This study shows that if your primary concern is reducing carbon dioxide emissions, growing biofuels is not the best way to do it.
“In fact it can have a perverse impact elsewhere in the world. The amount of carbon that is released when you clear forests to make way for the biofuel crop is much more than the amount you get back from growing biofuels over a 30-year period.
"You can't convert your car to run on biofuel and keep on driving and think that everything will be OK. You are turning a blind eye to what's happening around the world and that in fact, you could be making things much worse."
The report is co-authored by Renton Righelato of the World Land Trust - a charity that protects and restores threatened habitats around the world – and is published in Science this month.
The study compared the amount of carbon dioxide emissions that would be saved from entering the atmosphere by growing biofuels with the amount saved from slowing deforestation and restoring forests over a 30-year period.
The study also found that converting large areas of land back to forest provides other environmental benefits such as preventing desertification and regional climate regulation. The conversion of large areas of land to make biofuels will place further strains on the environment, the study concluded.
European Union member states have pledged to replace 10% of transport fuel with biofuel from crops by 2020 in an effort to reduce reliance on imported oil and reduce carbon dioxide emissions. Meeting the EU target would require an area larger than one third of all the agricultural land in Europe to be used for growing biofuel crops.
But Spracklen says that conserving existing forests and savannahs and restoring forests and grasslands is a better way to help save the planet.
He says: "There is a big push in the EU and US to promote biofuels as a way to reduce carbon dioxide emissions. What we do here has an impact on the rest of the world. Although biofuels may look a good idea in places like Europe, they have a perverse effect when you take into the rest of the world."
Source:"Carbon Mitigation by Biofuels or by Saving and Restoring Forests?" Renton Righelato and Dominick V. Spracklen, Science 17 August 2007:Vol. 317. no. 5840, p. 902