Biofuels could meet up to half the world's current fuel consumption without affecting food production or forests, argues a study published last month in the journal Environmental Science and Technology.
Analyzing the extent of marginal grasslands, including abandoned and degraded grassland, using data on soil, topography, climate and current land use, Ximing Cai of the University of Illinois at Urbana−Champaign and colleagues calculate that using low-impact high-diversity (LIHD) perennial grasses as biofuel feedstocks could meet up to 56 percent of current liquid fuel consumption. They estimate up to 1.4 billion hectares of land in Africa, China, Europe, India, South America, and the continental United States could be available for such "second-generation" energy crops. The researchers included only areas that would be watered by rainfall, not irrigation, in order to minimize the potential impact on food production.
But the researchers caution that the rosy projections could change once the effects of climate change are factored in. Furthermore, population growth and increasing affluence are expected to significantly boost energy demand in the future, increasing the need for land. Finally the researchers did not account for the impacts invasive species could have in non-native landscapes or social issues such as land tenure.
Still the authors say the study is a good starting point for future research that could affect policy decisions.
