United States Considers Biofuel Emissions
The Obama administration unveiled its first proposals for how the United States should implement its biofuels policies yesterday, announcing a plan to analyze the direct and indirect greenhouse gas emissions related to the renewable fuels.
The U.S. Environmental Protection Agency (EPA), the government body tasked with determining how to increase total biofuel consumption to 36 billion gallons by 2022, highlighted two timeframes for measuring the emissions caused by "biofuel-induced land use change," a key variable in ensuring that the fuels reduce emissions in the near future.
The agency acknowledged that shifting U.S. food crops, namely corn, to biofuel production reduces global food supplies and provides an incentive for farmers in other countries to clear their land for agriculture. When tropical forests, peatlands, and other lands that are rich in carbon are converted to cropland, large quantities of greenhouse gases are potentially released.
The EPA argues, however, that greater use of biofuels would ensure that U.S. vehicles burn fewer gallons of petroleum-based fossil fuels over time and reduce the overall impact of transportation on climate change.
Following a 60-day comment period on the proposed analysis method, the agency will determine the appropriate time period for studying emission reductions from the use of biofuels over their full lifecycles, from the growing of the feedstocks to end use in vehicles.
A shorter study period, such as 30 years, would encourage a speedier transition to more energy-efficient ethanol feedstocks and production facilities. A longer period, such as 100 years, could delay the transition and allow for continued production and widespread use of biofuels with less climate benefit, including corn ethanol produced in fossil fuel-fired facilities.
EPA Administrator Lisa Jackson insisted that the final rule would reduce fossil fuel consumption and the U.S. contribution to climate change. "We can cut greenhouse gas emissions equivalent to taking 20 million cars off the road," Jackson said in a conference call with reporters.
Under the nation's Renewable Fuels Standard (RFS), the U.S. Congress has required that advanced biofuels comprise 21 billion of the 36 billion gallons of renewable fuels blended annually into the fuel supply by 2022. The fuels are considered "advanced" if they reduce emissions by no less than half, compared with conventional gasoline. The RFS states that corn ethanol can supply as much as 15 billion gallons of biofuel annually, but new plants are required to produce ethanol that reduces emissions by 20 percent - based on an analysis of the fuel's overall lifecycle.
The EPA estimates that when land use changes are included, corn ethanol produced at a natural gas-fired mill (the large majority of the 169 ethanol plants currently in operation) would reduce emissions by 16 percent in a 100-year time span. But in the 30-year period, the same ethanol would more likely be disqualified from the RFS because less gasoline would be replaced during that time, causing an overall emissions increase of 5 percent.
By proposing multiple approaches to factoring lifecycle analysis into biofuels policy, the EPA has so far appeased the biofuel industry and environmentalists - interest groups that are often at odds. But the groups are preparing to battle over the eventual ruling.
Jeremy Martin, a senior scientist with the Union of Concerned Scientists, said that the EPA should study the lifecycle analysis of biofuels over a time period even shorter than the 30-year low that the agency suggested. He favors a 20-year focus.
"We need to address our climate challenges by 2030 and not 100 years from now. This 100-year timeframe doesn't make any sense at all," Martin said. "If the fuel is slightly better than gasoline 100 years from now, is that really a benefit?"
Bob Dinneen, president of the ethanol-friendly Renewable Fuels Association, questions the validity of evaluations that measure emissions from land use changes and other indirect sources. "Trying to evaluate indirect effects, in particular international effects, is highly dependent on assumptions used and the data available. There's a great deal of uncertainty about this," he said during a conference call with reporters. He insisted, however, that "if done correctly, such an analysis will demonstrate [that] a significant carbon benefit is achieved through the use of ethanol from all sources."Corn ethanol could qualify under the 30-year timeframe if a production facility used more efficient technologies such as combined heat and power, an integrated energy system that produces both electricity and heat - or if the plant were powered by biomass sources such as wood waste. Soy-based biodiesel would acheive a 22-percent emission reduction over conventional diesel in the 100-year scenario, but it would increase emissions by 4 percent in the 30-year prediction because less gasoline would be replaced, the EPA said.
Sugarcane ethanol, which is produced mainly in tropical regions, would reduce overall emissions in the 100- and 30-year outlooks by 44 and 26 percent, respectively. The Brazilian Sugarcane Industry Association (UNICA) is hoping the EPA's lifecycle emission analyses will result in an expanded market for southern Brazil's farmers, who already supply 25 percent of their country's fuel.
"We know sugarcane ethanol has the lowest carbon emissions of any liquid biofuel produced today," said Joel Velasco, UNICA's chief representative to the United States, in a statement. "We are certain that when the EPA considers the best available data and research, these indirect land use effects from sugarcane cultivation in Brazil will be marginal at best."
Regardless of the timeframe used in lifecycle analyses, existing corn-ethanol facilities are exempt from the rigorous emission-reduction rules if they came online before the U.S. Energy Independence and Security Act (EISA), which contains the updated Renewable Fuel Standard, became law in December 2007.
"15 billion gallons of ethanol are grandfathered under EISA - [ethanol that] one would expect [to be] coming from corn," Jackson said. "As the president has said, and I think the rule-making advances, corn-based ethanol is a bridge, an extraordinarily important bridge, but it's a bridge to more advanced forms of ethanol."
The grandfathered facilities, which include at least 20 coal-fired ethanol mills, could increase overall emissions, and their biofuel output could still be included in national renewable fuel mixes. In recognition of this loophole, the EPA has proposed that grandfathered facilities seeking to be included in the fuel program be barred from increasing in size or switching from natural gas to coal power sources.
Cellulosic ethanol, derived from fast-growing perennials or waste feedstocks such as switchgrass and corn stover, result in emissions reductions of more than 100 percent compared to conventional fuels, in either timeframe scenario, the EPA said. To encourage development of such "next-generation biofuels," the EPA, U.S. Department of Energy, and U.S. Department of Agriculture announced yesterday the creation of a Biofuels Interagency Working Group. The body will also form policies to increase production of "flexible-fuel" vehicles, which are able to run on a variety of fuel types.
The EPA plans to hold a public workshop on lifecycle analyses during the proposal's two-month comment period. Jackson said the agency is especially interested in feedback on the use of satellite data, emissions estimates for foreign crop feedstocks, and overall lifecycle emission models.
"The EPA is soliciting peer-reviewed scientific feedback to ensure the rule, when finalized, includes the best available science," Jackson said.
The United States was the world's leading producer of biofuels last year, generating nearly 10 billion gallons. Brazil ranked second at 6.8 billion gallons.
Ben Block is a staff
writer with the Worldwatch Institute. He can be reached at email@example.com.
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