EPA Proposes Rule to Reduce Global Warming Emissions from Biofuels

A new Environmental Protection Agency (EPA) draft rule to cut global warming emissions from biofuels "is a good starting point," but the agency should adopt a realistic time frame for reducing heat-trapping emission from fuels, according to experts at the Union of Concerned Scientists (UCS).

The rule, which the EPA announced today, provides various options to measure the amount of emissions biofuel crops produce. UCS experts say the agency's final rule should ensure that biofuels help reduce heat-trapping emissions in a timely manner. They also say the rule should complement other policies aimed at preventing the worst consequences of global warming.

"EPA is leading with the science and that should send a strong message," said Jeremy Martin, a UCS senior scientist. "The best biofuels take a big bite out of global warming emissions without gobbling up our food crops."

The EPA's draft rule provides estimates of emissions from a range of biofuels, including biodiesel and cellulosic ethanol, which come from a variety of feedstocks, and corn ethanol. The rule indicates the agency will measure heat-trapping emissions based on a biofuel's entire lifecycle, from cultivation to fuel production to vehicle exhaust.

Cultivation includes direct emissions from fertilizer and tractor fuel, as well as emissions from indirect land use change, which is the impact that growing biofuels domestically has on other countries. For example, shifting U.S. food crops to biofuel production triggers indirect land use emissions by reducing the supply of a specific food crop and driving up market prices. That jump in food crop price gives farmers in other countries the incentive to clear land to produce replacement crops. When those farmers clear tropical forests for farm land, or till previously untouched land, they release more heat-trapping emissions into the atmosphere.

California recently adopted a low carbon fuel standard that will account for indirect land use emissions. UCS helped produce a letter (pdf) from 179 prominent scientists and economists urging the state to accurately account for biofuel emissions. "Failure to include a major source of pollution, like indirect land use emissions," the letter stated, "will distort the carbon market, suppress investment in truly low carbon fuels, and ultimately result in higher emissions."

Indirect land use changes -- such as deforestation -- put a significant amount of heat-trapping emissions into the atmosphere in a relatively short period of time. By contrast, the emission reductions that result from using biofuels instead of gasoline are generally smaller and accrue over a longer period of time. EPA's initial findings suggest that if the rule accounted for total biofuel emissions over a 100-year time frame, corn ethanol would pollute less than gasoline, even when accounting for indirect land use change. Over the short-term, however, the same data indicate that expanding corn ethanol production in 2010 actually would increase global warming emissions through 2030.

"The EPA is doing the right thing by looking at all the pollution from biofuels," said Eli Hopson, a Washington representative with UCS's Clean Vehicle Program. "But we can't wait 100 years to begin to address climate change. We need better biofuels that deliver climate benefits within 20 years to help us meet emissions reduction goals."

The lifecycle analysis for the renewable fuel standard likely will serve as the basis for future fuel regulations. The next step the federal government may take regarding biofuels is to adopt a low carbon fuel standard. Such a standard would subject all transportation fuels -- including biofuels --- to the same type of lifecycle accounting and require a gradual reduction in average pollution. UCS experts expect the EPA to begin developing a federal standard using its authority under the Clean Air Act to enact policies that would reduce global warming emissions.