ABSTRACT. Public policy supports biofuels for their benefits to agricultural economies, energy security and the environment. The environmental rationale is premised on greenhouse gas (GHG, "carbon") emissions reduction, which is a matter of contention. This issue is challenging to resolve because of critical but difficult-to-verify assumptions in lifecycle analysis (LCA), limits of available data and disputes about system boundaries. Although LCA has been the presumptive basis of climate policy for fuels, careful consideration indicates that it is inappropriate for defining regulations.
The climate benefits of biofuels such as ethanol and biodiesel have been debated for many years. Attempts to compare these fuels with one another and fossil-derived fuels such as gasoline and diesel confront many uncertainties, not all of which can be resolved through further data analysis. By scrutinizing the greatest sources of uncertainty and grounding analysis in the areas of high certainty such as combustion chemistry and the terrestrial carbon cycle, this paper sheds light on this challenging subject and points the way toward new strategies for addressing CO2 emissions from transportation fuels.
Since 2005, the United States has embarked on a steady expansion of renewable fuels such as ethanol and biodiesel, widely touted as a win-win proposition for energy security and the environment. However, the promised breakthroughs in biofuel technology have greatly lagged the rapid ramp-up of production mandated by Congress while adverse side effects of the policy have become ever more clear.
Nathaniel Szymczak, the Dow Corning Assistant Professor of Chemistry and an Energy Institute Faculty Affiliate, was named a 2014 Alfred P. Sloan Foundation research fellow, along with two other U-M scientists. The award comes with a $50,000 research boost.