(150e) Land-Use Change Implications for Large-Scale Cultivation of Algae Feedstocks in the Southern United States

Algae is considered a promising source of biofuels for the future. Although several studies have been conducted to assess the environmental impacts of algae-based fuels, land use change is one area that is commonly overlooked in previous life cycle assessments. However, land-use change will impact the life-cycle greenhouse gas (GHG) emissions of algal biofuels when large tracts of land are converted to algal raceway cultivation systems. Our work within the National Alliance for Advanced Biofuels and Bioproducts (NAABB) research consortium has focused on conducting life-cycle assessment (LCA) studies to investigate key potential scenarios concerning algal biofuels development. Here we present study results on assessing the impacts of land use change through a variety of means. The Intergovernmental Panel on Climate Change Tier 1 methodology is incorporated to assess potential emissions resulting from the conversion of U.S. Gulf Coast and Southwest grassland, cropland, and forestland in several management conditions. This assessment is combined with guidance on promising sites for algae raceway development to provide an estimate of industry-wide GHG emissions impacts due to direct land-use change (dLUC). Direct LUC impacts appear to be significant, and could result in GHG emissions equivalent to one or several important processing stages of the algae-based fuels cycle such as algae dewatering and drying, especially if previously forested lands are cleared. Our presentation details the methods, assumptions and initial LCA results for these land use change scenarios of importance when considering the algae biofuels life cycle.  The results from this LCA can help decision-makers select the locations of algae cultivation facilities to minimize dLUC emissions.