A renewable energy source designed to reduce greenhouse gas emissions is contributing more to global warming than fossil fuels, a study suggests. Measurements of emissions from the burning of biofuels derived from rapeseed and maize have been found to produce more greenhouse gas emissions than they save.
Corn-derived renewable energy sources create more greenhouse gases than fossil fuels, according to a study from an international team of scientists reported in the London Times. Research findings published in the journal Atmospheric Chemistry and Physics calculate that corn and rapeseed biodiesels produce up to 70 percent and 50 percent more greenhouse gases respectively than fossil fuels.
The study focused on nitrous oxide, which is 296 times more powerful as a greenhouse gas than carbon dioxide. Scientists found that the use of biofuels released twice as much as nitrous oxide as previously realised. The research was performed by scientists from the U.S. Britain, and Germany and it included Professor Paul Crutzen, a Nobel Prize-winning ozone scholar.
The research team found that 3 to 5 per cent of the nitrogen in fertiliser was converted and emitted. In contrast, the figure used by the International Panel on Climate Change, which assesses the extent and impact of man-made global warming, was 2 per cent.
“One wants rational decisions rather than simply jumping on the bandwagon because superficially something appears to reduce emissions,” said Keith Smith, a professor at the University of Edinburgh and one of the researchers.
Professor Smith told Chemistry World: “The significance of it is that the supposed benefits of biofuels are even more disputable than had been thought hitherto.”
It was accepted by the scientists that other factors, such as the use of fossil fuels to produce fertiliser, have yet to be fully analysed for their impact on overall figures. But they concluded that the biofuels “can contribute as much or more to global warming by N2O emissions than cooling by fossil-fuel savings”.
Dr Dave Reay, of the University of Edinburgh, used the findings to calculate that with the US Senate aiming to increase maize ethanol production sevenfold by 2022, greenhouse gas emissions from transport will rise by 6 per cent.
Saturday, September 22, 2007
Biofuels Pollute More Than Gas?
From Fox News and London Times: