Noting that society “cannot afford to miss out” on the multiple benefits of biofuels “done right”, but that society also “cannot accept the undesirable impacts of biofuels done wrong,” eleven researchers suggest what they describe as a consensus position on beneficial biofuels in a paper published 17 July in Science.
Lead author is David Tilman of the University of Minnesota. Co-authors include the U of M’s Jonathan Foley and Jason Hill; Princeton’s Robert Socolow, Eric Larson, Stephen Pacala, Tim Searchinger and Robert Williams; Dartmouth’s Lee Lynd; MIT’s John Reilly; and the University of California, Berkeley’s Chris Somerville.
Biofuels can be produced in large quantities and still offer multiple benefits, but only if they come from feedstocks produced with low life-cycle greenhouse gas emissions, as well as minimal competition with food production, they state. The biofuels industry should focus on five major sources of renewable biomass:
- Perennial plants grown on degraded lands abandoned from agricultural use
- Crop residues
- Sustainably harvested wood and forest residues
- Double crops and mixed cropping systems
- Municipal and industrial wastes
Biofuels should receive policy support as substitutes for fossil energy only when they make a positive impact on four important objectives, they suggest: energy security, greenhouse-gas emissions, biodiversity, and the sustainability of the food supply. Evaluation of the greenhouse gas impact should include consideration of the effects of indirect land-use change.
The recent biofuels policy dialogue in the United States is troubling. It has become increasingly polarized, and political influence seems to be trumping science. The best available science, continually updated, should be used to evaluate the extent to which various biofuels achieve their multiple objectives, and policy should reward achievement. Three steps should be taken: meaningful science-based environmental safeguards should be adopted, a robust biofuels industry should be enabled, and those who have invested in first-generation biofuels should have a viable path forward.
In support of such policy, rigorous accounting rules will need to be developed that measure the impacts of biofuels on the efficiency of the global food system, greenhouse-gas emissions, soil fertility, water and air quality, and biodiversity. Accounting rules should consider the full life cycle of biofuels production, transformation, and combustion.
A central issue for the coming decades, then, is how the environmental impacts and potential benefits associated with meeting the global demand for food and energy can be internalized into our economic systems. This is a complex question that cannot be addressed with simplistic solutions and sound bites. It needs a new collaboration between environmentalists, economists, technologists, the agricultural community, engaged citizens, and governments around the world.—Tilman et al. (2009)
The discussions that led to the paper began in June 2008 at a workshop on biofuels and food hosted by the Carbon Mitigation Initiative (CMI), supported by BP and Ford. The CMI is a Princeton center headed by Socolow and Stephen Pacala, the Frederick D. Petrie Professor in Ecology and Evolutionary Biology and director of the Princeton Environmental Institute.
Individuals whose backgrounds span a broad range of perspectives gathered in Princeton, NJ, to exchange views about the sustainability of biofuels, food, and the environment. After considerable back-and-forth, we arrived at the consensus presented above. We are hopeful that colleagues charged with developing biofuels policies, who are likely to span a similarly broad range of views, will benefit from our deliberations.—Tilman et al. (2009)
David Tilman, Robert Socolow, Jonathan A. Foley, Jason Hill, Eric Larson, Lee Lynd, Stephen Pacala, John Reilly, Tim Searchinger, Chris Somerville, Robert Williams (2009) Beneficial Biofuels—The Food, Energy, and Environment Trilemma. Science Vol. 325. no. 5938, pp. 270 - 271 doi: 10.1126/science.1177970