New study says no land use change due to biofuels

A new study on indirect land use change (ILUC) due to biofuels (like ethanol) production indicates that the real impact of U.S. biofuels production on ILUC domestically and internationally is negligible or nonexistent.

Indirect land use change is important because some believe the environmental and greenhouse gas benefits of biofuels like ethanol are somewhat negated when other farmland is brought into production. However, ILUC is mostly a theory and has had little scientific support — yet regulatory bodies, such as the Air Resources Board in California, have tried to set renewable fuels standards that would exclude corn-based ethanol simply based on these theories. (For more click here, here and here.)

The study, "Indirect land use change for biofuels: Testing predictions and improving analytical methodologies" was coauthored by Dr. Seungdo Kim and Dr. Bruce E. Dale of Michigan State University. It was published in the July 2011 Biomass and Bioenergy Journal.

“It is the first evidence-based evaluation of ILUC utilizing actual historic data, employing a 'bottom-up', data-driven, statistical approach based on individual world regions’ land use patterns and commodity grain imports,” said Dr. Roger Conway, senior partner at Rosslyn Advisors LLC and former director of the United States Department of Agriculture's Office of Energy Policy and New Uses.

Very few previous studies have attempted to find empirical evidence for or against indirect land use change from the historical data. Most previous studies relied on global economic simulations. "Unlike most other ILUC work this study relied on very few assumptions and did not attempt to quantify nor to predict ILUC effects," commented Bruce Dale, coauthor of the study. "We searched for direct historical evidence for ILUC in relevant world areas rather than attempting to project or predict what course ILUC might take. Projecting forward can force scientists to make untestable assumptions."

One interpretation of no ILUC effects is that U.S. crop intensification absorbed and exceeded new ethanol production demand. It is also possible that the effects of biofuels production expansion on ILUC may simply be negligible. Past studies based on economic model assumptions often do not take into account new agricultural techniques that allow for greater crop yields on existing U.S. lands where biofuel corn is produced.

The new study used 1990 -- when the U.S. biofuels industry was very small -- as its baseline and then measured crop changes against that as U.S. ethanol production grew rapidly in subsequent years. In order to test the hypotheses that ILUC had occurred, the authors searched for actual land use change in 18 regions around the world where corn and/or soybeans are produced.

Had ILUC occurred, use of crop land and arable land would have increased while the area of natural ecosystem land would have declined. Further, grain shipments from the U.S. to the other regions would decline. Finally, cropland in other regions would positively correlate with changes in harvested areas for corn and soybeans in the U.S.

Using historical data to investigate real ILUC effects, the study found no statistical evidence of the changes predicted by ILUC theory in any of the 18 world regions. "Prior modeling studies that relied on many assumptions have led to inflated projections for indirect land use change," added Dr. Steffen Mueller of the Energy Resources Center at the University of Illinois at Chicago. "Some work has substituted other data, such as the price of corn, to project ILUC. Modeling is important, but all models need to be tested and verified. These findings show that there is no substitute for using actual historic data when investigating ILUC."

Because other studies based their projections on economic model assumptions rather than empirical land use data their predictions on the effects of ILUC due to increased U.S. ethanol production varied widely.