Tallying Biofuels' Real Environmental Cost

Are biofuels really green? A pair of new studies in the Oct. 22 issue of Science damningly demonstrate that the answer is no, at least not the way we currently create and use them.
In the first study, a team of researchers led by Jerry Melillo of the Marine Biological Laboratory in Woods Hole, Mass., projected the effects of a major biofuel expansion over the coming century and found that it could end up increasing global greenhouse-gas emissions instead of reducing them. In the second paper, another team of researchers led by Tim Searchinger of Princeton University uncovered a potentially damaging flaw in the way carbon emissions from bioenergy are calculated under the Kyoto Protocol and in the carbon cap-and-trade bill currently being debated in Congress. If that error in calculation goes unfixed, a future increase in biofuel use could end up backfiring and derailing efforts to control global warming, according to the paper. “Biofuels can be an important part of the portfolio of climate-change activities,” says Steve Hamburg, chief scientist for the Environmental Defense Fund and a corresponding author on the second Science paper. “But we have to make sure we incentivize the right way, or we could end up with perverse outcomes.”

The problem is that biofuels are treated as if they were 100% carbon neutral, even though they are clearly not. When ethanol is burned, for instance, it still releases CO2 into the atmosphere. After all, the plants that go to make biofuels are made of carbon, just as oil and other fossil fuels are. Further, the use of biofuels would reduce total greenhouse-gas emissions only if their creation were to increase — or at least not displace — existing plant growth, which naturally takes carbon out of the atmosphere. For example, if the wood chips left over from logging were used to make biofuel, overall greenhouse gas emissions would be reduced, since that wood waste would have decomposed on the forest floor and released as carbon into the atmosphere anyway. By using them for fuel, it not only replaces some fossil fuel but also does not destroy plant life.

But that’s rarely how it works in most biofuel production today.

Time