For the last few years, environmental advocates and ethanol producers have been mired in a debate over something known as indirect land use change (ILUC), a measure of greenhouse gas (GHG) emissions caused by, but not directly associated with, biofuel production. The controversy centers on these questions: Does ethanol demand in the U.S. and other countries lead to destruction of forests and other carbon-sequestering ecosystems in countries other than where the ethanol or the crops used to make it are produced? And if it does, can the GHG emissions associated with those land use changes be accurately quantified and used for regulatory carbon footprint assessments?

For the moment, the debate has cooled. In 2010, the Environmental Protection Agency (EPA) released a final rule stating that it would utilize ILUC estimates as part of the carbon footprints it calculates to determine whether biofuels like corn ethanol can meet federal mandates, which are now tied to GHG emissions performance. Similarly, California decided in 2009 to include ILUC impacts as part of its low-carbon fuel standard (LCFS).  

But the debate is not over. In the EU, the European Commission is currently studying policy options to deal with ILUC. And opponents of ILUC in the U.S. have demonstrated that they will continue to try to get those estimates taken out of federal and state energy policies—ILUC was featured prominently in a lawsuit the ethanol industry brought against California’s LCFS that recently derailed that regulation’s implementation (Rocky Mountain Farmers Union et al v. Goldstene, 2011)..

One outcome of the ILUC debate is that it has deepened the already growing divide between environmental advocates and many U.S. farmers and agricultural organizations. Without some resolution, ILUC will continue to be a barrier to the coming together of U.S. farmers and environmentalists around on-farm GHG reductions and improved carbon sequestration—a crucial step toward climate mitigation success.

Perhaps the reason the ILUC debate has become so contentious is because at its core lie two questions that are not easy for either biofuel proponents or environmental advocates to answer: How do we stem agriculture’s negative effects on the environment while still meeting food, energy and materials demand from the land? And, who—or what—is to blame when pressure to expand agricultural land destroys carbon-sequestering ecosystems?

As originally published, the essay misstated that a U.S. district court ruling found corn ethanol unfairly discriminated against due to ILUC. The ruling, which halted enforcement of California’s LCFS, found that other aspects of the California Air Resources Board’s lifecycle assessment for Midwestern corn ethanol unfairly increased that product’s carbon footprint, as compared to California-produced ethanol.