By Ben Geman - 01/28/11 04:25 PM EST
The report comes as ethanol is already under attack from some environmentalists, and lawmakers seeking to strip tax subsidies. But renewable fuels are valued as a way to displace oil reliance and boost rural economies, and retain powerful political support on Capitol Hill.
Elsewhere, the report addresses effects on wildlife and habitat. “Increased cultivation of feedstocks for biofuel could significantly affect biodiversity through habitat alteration when uncultivated land is put into production,” it states, also noting risks of plant and animal exposure to pesticides, nutrient runoff into waters and other effects.
“Feedstocks” refers to the source of the fuels, such as corn, soybeans, grasses and wood materials.
Corn is the dominant source for U.S. ethanol today. But the 2007 law, which mandates an expansion of U.S. biofuel use to reach 36 billion gallons annually in 2022, caps corn ethanol at 15 billion gallons, while the balance must come from “advanced” biofuels made from sources like agricultural residues and perennial grasses.
EPA posted the draft report online Friday, but the document cautions that it’s for review purposes and “does not constitute Agency policy.”
The agency plans to produce a final report for Congress after peer review (the 2007 law mandates triennial reports on the environmental impacts of increased biofuels production and use).
The report reiterates EPA’s conclusion that meeting the biofuels mandate in the 2007 law will lead to a net reduction in carbon dioxide emissions compared to petroleum-based fuels.
It also explores the international effects of expanded biofuels development, noting that increased U.S. production and use will affect trade patterns and prices.
The report states: “This will result in land use change and effects on air quality, water quality, and biodiversity. Direct and indirect land use changes will likely occur across the globe as the U.S. and other biofuel feedstock-producing countries alter their agricultural sectors to allow for greater biofuel production. Many locations where biofuel production is growing, such as Indonesia, Malaysia, and Brazil, are also areas of high biodiversity value. Depending where biofuel feedstock production occurs, and to what extent the level of production increases with time, impacts to biodiversity could be significant.”
The report notes that most aspects of the biofuels supply chain are already “regulated, subject to limitations, or mitigated through various approaches.”
But it nonetheless calls for further steps to address harms, such as improved federal agency efforts to develop and implement “best management” and conservation practices, and international scientific cooperation to identify and implement sustainable techniques.