http://blog.wired.com/wiredscience/2008/02/studies-say-bio.html wrote:Studies Say Biofuels Worse Than Gasoline
By Brandon Keim EmailFebruary 08, 2008 | 11:19:56 AMCategories: Energy, Government, Plants
Biofuelcover When all relevant factors are accounted for, biofuels produce more greenhouse gas emissions than fossil fuels.
So conclude two studies published yesterday in Science, adding to a growing body of research suggesting that crop-based fuels, once hailed as a clean answer to oil, are not a magic green bullet.
Biofuels seemed so promising at first -- what could be cleaner than running our cars and factories on plants? But early prognostications were a bit thin on details. They didn't always account for the energy that would be needed to grow, harvest and refine the fuels. Most importantly, they didn't consider that greenhouse gas-gobbling vegetation would need to be cleared for fuel crops -- or, if these were planted on existing pastures, that new fields would be cleared to make space for displaced food crops.
Put these factors in the equation, and biofuels don't do much good at all. The first study, led by Princton University environmental law researcher Timothy Searchinger, found that replacing fossil fuels with corn-based ethanol -- the darling of the U.S. biofuel industry -- would double greenhouse gas emissions for the next thirty years. Even switchgrass, seen as a far more efficient alternative, would produce a 50% bump in emissions.
Over time, as the incremental sequestration of CO2 in their roots matched the CO2 once stored by cleared vegetation, using biofuels probably would cut emissions -- but that could take decades. And the second study, authored by Nature Conservancy researchers, pegged that timetable at the level of centuries.
A bright spot, though: the Nature Conservancy said crops grown on degraded farmland that couldn't support food crops could be beneficial, as could biofuels made from agricultural waste.
An argument could be made that neither of the studies accounted for anticipated advances in fuel crop efficiency, but the drawbacks described by the studies are so massive that the conclusions would likely hold.
Whether policymakers will heed biofuel cautionaries, of which these studies are merely the latest, remains to be seen. Many countries and agrobusiness companies have already invested heavily in biofuels, and capital keeps pouring in. Biofuels have gone mainstream.
But opposition is going mainstream, too: the United Nations has set up a committee to evaluate biofuel sustainability, and the New York Times reports that leading environmental biologists are pushing President Bush and House of Representatives head Nancy Pelosi to reform biofuel policies.
If we really do have Science Debate 2008, I'd love to see the candidates -- especially Barack Obama -- grilled on this.
Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change
Land Clearing and the Biofuel Carbon Debt
Image: Detail from Biofuels: towards a greener and secure energy future
See Also:
* Can't See the Forest for the Biofuels
* Don't Pick Biofuel Winners Before the Race Starts
* The Best Way to Judge a Biofuel
* Making Deforestation Unprofitable is Key to Bali Success
* Some Biofuels Are Better Than Others
