Assessing environmental externalities of transportation fuels

Abstract

The purpose of this study was to estimate the environmental externalities associated with various transportation fuels in the United States. We used GREET—a life-cycle analysis model; FASOM-GHG—a partial equilibrium dynamic optimization model on agriculture and forestry; APEEP—an integrated assessment model to calculate the marginal damage of emissions; the GTAP-BIO model—a computable general equilibrium model to estimate global land use and land cover changes due to biofuels policies; and the OSIRIS model to estimate the species extinctions based on deforestation due to biofuels policy scenario results. The FASOM-GHG- and GREET-based analysis on incorporating regional variation in crop yields and inputs did not reveal any significant variation in ethanol-based GHG emissions across the regions. The GTAP-BIO model-based global deforestation rates due to implementation of US Renewable Fuels Standard (RFS2) policies for first-generation biofuels, when applied to the OSIRIS model, indicated insignificant loss in biodiversity. These estimations would help in understanding whether a particular transportation fuel technology is environmentally sustainable and benefits the economy.