Biofuels emissions may be 'worse than petrol'

Biofuels, once seen as a useful way of combating climate change, could actually increase greenhouse gas emissions, say two major new studies.

And it may take tens or hundreds of years to pay back the "carbon debt" accrued by growing biofuels in the first place, say researchers. The calculations join a growing list of studies questioning whether switching to biofuels really will help combat climate change.

Biofuel production has accelerated over the last 5 years, spurred in part by a US drive to produce corn-derived ethanol as an alternative to petrol.

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