Editorial
Biofuels: good science must precede good policy Author info: Bruce E. Dale, Michigan State University, USA Contact: bdale@egr.msu.edu
n the United States, both the federal Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) are struggling with the issue of indirect land use change (ILUC) and its potential effects on the greenhouse gas performance of biofuels. A similar struggle is going on within the European Union (EU). As the time of writing, the regulatory outcome is far from certain. US law requires that ILUC estimates meet standards of scientific significance and life cycle analysis. The ILUC theory refers to bringing new lands into agricultural production because of market forces. For example, corn rendered unavailable to the world market because of ethanol production in the USA could hypothetically be replaced by converting new land to agriculture. The land conversion event might create a large, one-time carbon ‘debt’ (e.g., by burning tropical forests) which the inherent greenhouse gas benefits of the biofuel system could require centuries to ‘repay’. A single paper in Science in February 2008 describing potential greenhouse gas impacts of ILUC, along with intense, related media coverage, has cast a pall over all biofuels and chilled investment in advanced non-grain-based biofuels. But that paper does not meet standards for scientific significance or life cycle analysis. No actual data connect corn ethanol production with, to cite a widely quoted example, clearing the Amazon rainforest. Instead, the paper’s conclusions depend entirely on seven linked models and many assumptions. The validity of these assumptions and the reliability of the models are now being explored. Thus far, the paper is not holding up well to scrutiny. For example, other modeling predicts that hypothetical ILUC will occur primarily in US grasslands and commercial forests, not in tropical forests. My research group has shown that appropriate land-management strategies following land use change can greatly reduce the carbon debt. Dr Lee Lynd’s group (Dartmouth College) has demonstrated that
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© 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
ILUC analysis does not meet standards of scientific significance yet
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BE Dale
Editorial
using the standing forest biomass (e.g., to produce biofuels or pulp and paper) can also significantly reduce the debt. When productive use of standing biomass is combined with good land management following the land-conversion event, the carbon debt disappears. The Science study considers only the worst case for land management following land use change and makes no productive use of standing biomass. Until its conclusions are supported by independent analyses using a variety of tools and assumptions, the paper cannot be regarded as scientifically significant. The International Standards Organization (ISO) established parameters for lifecycle analysis. They include: i) using the most recent data, ii) making appropriate comparisons, iii) determining the sensitivity of results to changes in major assumptions and data, and iv) allocating environmental impacts among all system products. The Science paper does not meet these standards. For example, the paper assumes that all land use change is driven by agricultural expansion. Land use change, in fact, is due to multiple factors including infrastructure development (e.g., road and bridge construction) and timber harvest as well as agricultural expansion. In over 150 instances of observed land use change, mostly in the tropics, simple agricultural expansion was sufficient to explain only 4% of the cases. For more than 80% of the observed cases of land use change, however, a cluster of three factors – infrastructure development, timber harvest and agricultural expansion – were all present together. Agricultural expansion is rarely the sole force driving land use change. In another incongruity, the paper compares future ethanol production with past gasoline production; but life cycle principles demand that the new, or incremental, gallon of biofuel ethanol be compared with the incremental gallon of gasoline. Most new gasoline today in the USA is coming from the Athabasca tar sands of Canada and Venezuelan heavy crude. Processing these feedstocks releases much more greenhouse gases per gallon than conventional oil; up to three times as much. Therefore including just this one factor in the analysis reduces the hypothetical ILUC carbon debt substantially. Regulating biofuels production based upon the imputed ILUC impacts of their feedstocks production will likely not affect the land use changes of concern to environmental groups; but it has significant potential to undermine the development of low greenhouse gas biofuels. In fact, ILUC makes farmers and biofuel producers responsible for the greenhouse gas emissions of their competitors around the world; a burden no other industry bears. The issue is one of simple fairness. Regulatory agencies charged with implementing energy and climate policy, including EPA and CARB in the USA and others in the EU, should recognize that ILUC analysis currently does not meet standards of scientific significance or life cycle analysis. It should therefore not be used to formulate policy. Sound science must come before sound policy.
Bruce E. Dale Editor-in-Chief DOI: 10.1002/bbb.121
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© 2009 Society of Chemical Industry and John Wiley & Sons, Ltd | Biofuels, Bioprod. Bioref. 3:1–2 (2009); DOI: 10.1002/bbb