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. The idea makes
intuitive environmental sense - plants take up carbon dioxide as
they grow, so biofuels should help reduce greenhouse gas
emissions - but the full environmental cost of biofuels is only
now becoming clear. Extra emissions are created from the
production of fertiliser needed to grow corn, for example,
leading some researchers to predict that the energy released by
burning ethanol is only 25% greater than that used to grow and
process the fuel. The