A new study casts serious doubt on ethanol's status as a green wonder-fuel. In the Proceedings of the National Academy of Sciences, researchers lay out a series of grim findings about corn-based biofuel.Runoff from large-scale corn cultivation contaminates waterways with nitrogen, phosphorus, and pesticides. As a motor fuel, corn-based ethanol generates just 23 percent more energy than is required to make it. And finally, corn ethanol reduces greenhouse-gas emissions by a slim 12 percent over gasoline. The study found that soybean biodiesel outperforms the corn, but that "neither can replace much petroleum without impacting food supplies."
The best biofuel bet would be still-in-the-lab cellulosic ethanol made from switchgrass or other woody plants, but most researchers agree that even widespread cellulosic ethanol production would have nowhere near the output to replace gasoline.
Researchers also said that people are just going to have to get used to driving less, and quit bitching and moaning about it.
No, wait, that was me.
2 comments:
These results echo results from british researchers published last year [in Nature, if I recall correctly] that ethanol, as now produced and biodiesels as well are net negative impacts when all the environmental impacts of their production are factored in.
The blizzard of claims and counterclaims and studies is bewildering. Always gets my skeptic's guard up when subsidies are at stake and hinge on the existance of favorable "scientific" findings.
Check here under the heading "net energy" to see the sort of objections that have been compiled against uncritical support for biofuels. The Pimental and Patzek paper is reviewed favorably for balance in a number of other places.
Even if the energetics and chemistry pencil out in the black, where, and by who's labor we obtain biofuels are still issues, as Monbiot has pointed out. Later, Monbiot found a calculation by Jeffery Dukes that we couldn't replace a modest fraction of our current petroleum energy consumption with biofuels without flattening what remains of the worlds tropical forests.
All of this is really just a footnote to what should be my comment here: Yer damn straight, Shokai!
I just found this report that some citizens put together for an Ithaca NY regional planning group. It is the most thorough thing I have seen but the bottom line is just as you suggest: get used to driving less.
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