Forget biofuels - burn oil and plant forests instead
By Catherine Brahic
20 aug 2007
It sounds counterintuitive, but burning oil and planting forests to compensate is more environmentally friendly than burning biofuel. So say scientists who have calculated the difference in net emissions between using land to produce biofuel and the alternative: fuelling cars with gasoline and replanting forests on the land instead.
They recommend governments steer away from biofuel and focus on reforestation and maximising the efficiency of fossil fuels instead.
The reason is that producing biofuel is not a "green process". It requires tractors and fertilisers and land, all of which means burning fossil fuels to make "green" fuel. In the case of bioethanol produced from corn – an alternative to oil – "it's essentially a zero-sums game," says Ghislaine Kieffer, programme manager for Latin America at the International Energy Agency in Paris, France.
What is more, environmentalists have expressed concerns that the growing political backing that biofuel is enjoying will mean forests will be chopped down to make room for biofuel crops such as maize and sugarcane. "When you do this, you immediately release between 100 and 200 tonnes of carbon [per hectare]," says Renton Righelato of the World Land Trust, UK, a conservation agency that seeks to preserve rainforests.
Century-long wait
Righelato and Dominick Spracklen of the University of Leeds, UK, calculated how long it would take to compensate for those initial emissions by burning biofuel instead of gasoline. The answer is between 50 and 100 years. "We cannot afford that, in terms of climate change," says Righelato.
"You get far more carbon sequestered by planting forests than you avoid emissions by producing biofuels on the same land"
"policy makers may be better advised in the short term to focus on increasing the efficiency of fossil fuel use, to conserve existing forests and savannahs, and to restore natural forest and grassland habitats on cropland that is not needed for food."
Journal reference: Science (DOI:10.1126/science.1141361)
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