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Biofuels Switch a Mistake, Say Researchers    [

    Forget Biofuels - Burn Oil and Plant Forests Instead
    By Catherine Brahic
    NewScientist.com

    Thursday 16 August 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 (see Complete carbon footprint of biofuel - or is it?).

    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.

    The researchers also compared how much carbon would be stored by replanting forests with how much is saved by burning biofuel grown on the land instead of gasoline.

    They found that reforestation would sequester between two and nine times as much carbon over 30 years than would be saved by burning biofuels instead of gasoline (see bar chart, right). "You get far more carbon sequestered by planting forests than you avoid emissions by producing biofuels on the same land," says Righelato.

    He and Spracklen conclude that if the point of biofuels policies is to limit global warming, "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."

    They do admit, however, that biofuels made from woody materials such as prairie grasses may have an advantage over reforestation - although it is difficult to say for now as such fuels are still in development (see Humble grasses may be the best source of biofuel).

    Forests at high latitudes have been found to sequester less carbon than tropical forests (see Some forests may speed global warming). But Righelato says this does not affect his calculations as biofuel crops are not, by and large, grown in these areas.

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    Journal reference: Science (DOI:10.1126/science.1141361)

 

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    Go to Original

    Biofuels Switch a Mistake, Say Researchers
    By Tristan Farrow
    The Guardian UK

    Friday 17 August 2007

    Increasing production of biofuels to combat climate change will release between two and nine times more carbon gases over the next 30 years than fossil fuels, according to the first comprehensive analysis of emissions from biofuels.

    Biofuels - petrol and diesel extracted from plants - are presented as an environmentally friendly alternative to fossil fuels because the crops absorb carbon dioxide from the atmosphere as they grow.

    The study warns that forests must not be cleared to make way for biofuel crops. Clearing forests produces an immediate release of carbon gases into the atmosphere, accompanied by a loss of habitats, wildlife and livelihoods, the researchers said.

    Britain is committed to substituting 10% of its transport fuel with biofuels under Europewide plans to slash carbon emissions by 2020.

    "Biofuel policy is rushing ahead without understanding the implications," said Renton Righelato of the World Land Trust, a conservation charity. "It is a mistake in climate change terms to use biofuels."

    Dr Righelato's study, with Dominick Spracklen from the University of Leeds, is the first to calculate the impact of biofuel carbon emissions across the whole cycle of planting, extraction and conversion into fuel. They report in the journal Science that between two and nine times more carbon emissions are avoided by trapping carbon in trees and forest soil than by replacing fossil fuels with biofuels.

    Around 40% of Europe's agricultural land would be needed to grow biofuel crops to meet the 10% fossil fuel substitution target. That demand on arable land cannot be met in the EU or the US, say the scientists, so is likely to shift the burden on land in developing countries.

    The National Farmers Union said 20% of Britain's agricultural land could be used to grow biofuels by 2010. However, the researchers say reforesting the land would be a better way to reduce emissions.

    Biofuels look good in climate change terms from a Western perspective, said Dr Spracklen, but globally they actually lead to higher carbon emissions. "Brazil, Paraguay, Indonesia among others have huge deforestation programmes to supply the world biofuel market", he said.

    The researchers say the emphasis should be placed on increasing the efficiency of fossil fuel use and moving to carbon-free alternatives such as renewable energy.