These studies published in Science highlight a point I have been making for years. ‘Green” technologies have real environmental costs that need to be considered by policymakers. Unfortunately as soon as something is labeled ‘green’ many people assume that environmental costs are no longer a concern, and unfortunately as these studies point out that is simply not the case.
Converting corn to ethanol in Iowa not only leads to clearing more of the Amazonian rainforest, researchers report in a pair of new studies in Science, but also would do little to slow global warming—and often make it worse.
“Prior analyses made an accounting error,” says one study’s lead author, Tim Searchinger, an agricultural expert at Princeton University. “There is a huge imbalance between the carbon lost by plowing up a hectare [2.47 acres] of forest or grassland from the benefit you get from biofuels.”…
Tilman and his colleagues examined the overall CO2 released when land use changes occur. Converting the grasslands of the U.S. to grow corn results in excess greenhouse gas emissions of 134 metric tons of CO2 per hectare—a debt that would take 93 years to repay by replacing gasoline with corn-based ethanol. And converting jungles to palm plantations or tropical rainforest to soy fields would take centuries to pay back their carbon debts. “Any biofuel that causes land clearing is likely to increase global warming,” says ecologist Joseph Fargione of The Nature Conservancy, lead author of the second study. “It takes decades to centuries to repay the carbon debt that is created from clearing land.”…
“We shouldn’t abandon biofuels,” Searchinger says. But “you don’t solve global warming by going in the wrong direction.”
Luckily my favorite solution for biofuels escaped evisceration by these studies, and it still seems to me that making fuel from algae is our best bet. Though of course as with everything we need to be aware of all the costs of implementing this technology on a large scale.
Leave a Reply