A recent analysis by Iowa State University Biofuels Economist Robert Wisner argues that requirements for biofuel production are on a collision course with greenhouse gas reduction goals. He notes that the Energy Independence and Security Act’s requirement for gradual increases in production of biofuels “was designed to provide time for technology development and industry growth.” However, he says, California’s and the EPA’s requirement for immediate reductions in greenhouse gas emissions may block the industry’s growth.
Wisner notes some of the large uncertainties in producing accurate, science-based measurements of indirect land use change emissions:
Longer-term technological changes that bring increased crop yields per acre, changes in livestock and poultry feed conversion efficiency that reduce feed needs per animal, the amount of crop residue left on soils, and other factors will affect indirect land use emissions.
When the EISA was first debated and passed, the prevailing theory was that an annual increase in corn production would be sufficient to meet the new demand created by the annual increase in biofuel production. See for instance, U.S. Corn Growers: Producing Food and Fuel from the National Corn Growers Association.
The new models being employed by California and the EPA, however, take as an assumption that the increase in biofuel demand represents a shock to the system that happens all at once. See, for instance, The Land Use Effects of Corn-Based Ethanol, by Thomas Darlington. The models change a key assumption about the effects of the Renewable Fuel Standard, coloring the conclusion drawn. Both assumptions should be open for testing as hypotheses.