Growing crops to make biofuels results in vast volumes of carbon dioxide being released into the atmosphere and does nothing to stop climate change or global warming, according to the first thorough scientific audit of a biofuel's carbon budget.
Scientists have produced damning evidence to suggest that biofuels could be one of the biggest environmental con tricks because they actually make global warming worse by adding to the man-made emissions of carbon dioxide that they are supposed to curb.
Two separate studies published in the journal Science show that a range of biofuel crops now being grown to produce "green" alternatives to oil-based fossil fuels release far more carbon dioxide into the air than can be absorbed by the growing plants.
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The scientists found that, in the case of some crops, it would take several centuries of growing them to pay off the carbon debt caused by their initial cultivation.
Those environmental costs do not take into account any extra destruction of the environment, for instance the loss of biodiversity caused by clearing tracts of pristine rainforest.
"All the biofuels we use now cause habitat destruction, either directly or indirectly," said Joe Fargioine of the United States Nature Conservancy, who was the lead scientist in one of the studies.
"Global agriculture is already producing food for six billion people. Producing food-based biofuel too will require that still more land be converted to agriculture."
Both studies looked at how much carbon dioxide is released when a piece of land is converted into a biofuel crop. They found that when peat lands in Indonesia are converted into palm-oil plantations, for instance, it would take 423 years to pay off the carbon debt.
The next worse case was when forested land in the Amazon is cut down to convert into soya-bean fields.
The scientists found that it would take 319 years of making biodiesel from soya beans to pay off the carbon debt caused by chopping down the trees in the first place.
Such conversions of land to grow maize and sugarcane for biodiesel, or palm oil and soya beans for bioethanol, release between 17 and 420 times more carbon than the annual savings from replacing fossil fuels, the scientists calculated.
"This research examines the conversion of land for biofuels and asks the question: 'Is it worth it?' And surprisingly the answer is 'no', Fargione said. "These natural areas store a lot of carbon, so converting them to crops results in tons of carbon emitted into the atmosphere."
Jimmie Powell, a member of the scientific team at the US Nature Conservancy, said: "In finding solutions to climate change, we must ensure that the cure is not worse than the disease."
The European Union is already having second thoughts about its policy aimed at stimulating the production of biofuel.
Stavros Dimas, the EU environment commissioner, admitted last month that the EU did not foresee the scale of the environmental problems raised by Europe's target of deriving 10 percent of its transport fuel from plant material.
Professor Stephen Polasky of the University of Minnesota, an author of one of the studies published in Science, said: "We don't have the proper incentives in place because landowners are rewarded for producing palm oil and other products, but not rewarded for carbon management.
"This creates incentives for excessive land clearing and can result in large increases in carbon emissions." - Foreign Service
- This article was originally published on page 6 of Sunday Independent on February 10, 2008
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