New analysis shows that without proper regulation, biofuels programs aimed at curbing greenhouse gases could do just the opposite
A global push toward production of biofuels, advocated by many as a measure to curb greenhouse gas emissions, could have exactly the opposite effect unless adequate controls are put in place, a new study has found. Because forests, which remove carbon dioxide from the atmosphere, could end up being cut down to create new cropland as a result of intensive agriculture for fuels, a gallon of biofuel could ironically end up being responsible for twice as much greenhouse gas emission as a gallon of gasoline.
This indirect impact from biofuels production is "an inescapable effect" unless regulations control it, but it cannot directly be measured, says John Reilly, associate director of the MIT Joint Program on the Science and Policy of Global Change. Reilly, along with five other MIT researchers, is a co-author of the new study published Oct. 23 in Science. The lead author is Jerry Melillo of the Marine Biological Laboratory in Woods Hole, Mass.
The study found that a massive campaign to substitute biofuels for petroleum could result in a net doubling of the amount of land devoted to agriculture worldwide - and that, perhaps surprisingly, there is enough land available to sustain that. But this change in land use, unless coupled to regulations that either specifically protect forestland, or that tax the destruction of forest sufficiently to render that uneconomic, would lead to a net increase in carbon emissions. In addition, the increase in intensive agriculture would require an enormous addition of nitrogen fertilizers to the soil, producing emissions of nitrous oxide, a much more potent greenhouse gas than CO2. Together, these two effects could double the overall emissions attributable to land use. However, with proper controls in place, the use of biofuels instead of petroleum could reduce carbon emission by almost four-fifths, Reilly says.