Abstract

Recent biofuels regulations and supporting land use models assess the use of sensitive and high carbon lands for biofuels production. However, the precautionary land use limits set by these efforts ignore the large available lands in the United States. Using 2010 United States Department of Agriculture Cropland Data Layers, this study assessed current and available lands in the continental United States at different regional scales and compared the findings to regulatory limits and selected modeling scenarios. The Cropland Data Layer analysis identifies 100 million hectares in crops and 90 million hectares of available lands. That total is 28 million hectares higher than the baseline set by the United States Environmental Protection Agency regulations (of 162 million hectares) for agricultural land that qualifies for biofuels production. Secondly, the present study shows that land requirements predicted for common biofuels production scenarios by the Global Trade and Analysis Project (GTAP) are a small fraction of the 90 million hectares of available lands across all agro-ecological zones (AEZ) in the United States. In fact, modeled land use changed from 11.5 billion gallons of corn ethanol production required just over 2% of available lands while an additional 7 billion gallons of switch grass ethanol required close to 10% of available lands. Expansion of agriculture for biofuels production should be directed towards conversion of vastly available lands. The use of cropland data layers could be an accurate tool to track and verify available lands conversions.

Key words: Ethanol, biofuels, land use, cropland data layer.