Calculating CO2 Reductions For Biofuels

A new paper in the peer-reviewed journal Science illustrates "a critical accounting error" in the way carbon emissions from biofuels are measured in climate-change programs world-wide. Ethanol actually generates the same amount of greenhouse gas as fossil fuels, or more, per unit of energy. But this was still supposed to be better than coal or oil because ethanol's CO2 is "recycled." Since plants absorb and store carbon that is already in the atmosphere, burning them as fuel would create no new emissions, whereas fossil fuels release CO2 that has been buried for millions of years.

Climate change programs may end up treating biofuels as carbon-neutral, but the science study argues that this is a false economy because it doesn't consider changes in land use. If mature forests are cleared to make room for biofuel-growing farms, then the carbon that would otherwise accumulate in those forests ought to be counted on ethanol's balance sheet as well. So if Malaysians burn down a rain forest to grow palm oil that ends up in German biodiesel, Malaysia doesn't count the land-use emissions and Germany doesn't count the tail-pipe emissions.

Of course, the Center still believes biofuels should be a big part of America's energy mix. (WSJ, 10/29/09)