As scientists question the greenness of biofuels, the number of Americans who believe the planet is warming due to man-made pollution is at its lowest point in three years, according to a survey.
A poll of the US public by the Pew Research Center reports that only 57 percent - down from 77 percent three years ago - believe there is strong scientific evidence that the Earth has become warmer over recent decades and, as a result, are viewing the problem as less serious.
And to add fuel to global warming critics' arguments, an 'accounting error' in the way greenhouse gas emissions are calculated has emerged because fuel derived from plants and other organic sources, including ethanol, is considered to have no effect on carbon dioxide in the atmosphere, despite producing the same emissions as regular fuels.
The study, published this week in Science, says that biofuels, marketed as a low-carbon alternative, will actually emit more carbon dioxide than burning gasoline over the coming decades.
While there might be an argument saying biofuels grown on brownfield sites are carbon neutral because they absorb Co2 from the atmosphere while they are being cultivated, in most cases, existing forests are cleared to make room for the crops which absorb less Co2 than the trees they replace.
The problem stems from a basic error in the Kyoto Protocol - and subsequently copied into European and US environmental legislation - which calculates emissions without taking the source of the fuel into account.
"We made an honest mistake within the scientific framing of the debate, and we've got to correct it to make it right," said the paper's author, Steven Hamburg, chief scientist at the Environmental Defense Fund.
"It literally means you can chip up the world’s forests and burn them for fuel without noting the effect on the world’s greenhouse gases," adds Timothy Searchinger, a research fellow at Princeton University.
Meanwhile, the Pew report claims that the public is becoming less concerned about environmental issues as the recession continues to bite.
"The priority that people give to pollution and environmental concerns and a whole host of other issues is down because of the economy and because of the focus on other things," says Pew's Andrew Kohut. "When the focus is on other things, people forget and see these issues as less grave."