Assessing environmental externalities of transportation fuels

By Dileep Birur, Robert Beach, Ross Loomis, Michael Gallaher, David Dayton

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.


Birur, D., Beach, R., Loomis, R., Gallaher, M., & Dayton, D. (2013). Assessing environmental externalities of transportation fuels. (RTI Press Publication No. RB-0004-1306). Research Triangle Park, NC: RTI Press.

© 2019 RTI International. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.


Dileep BirurDileep K. Birur, PhD, is a research economist in the Agriculture, Resource & Energy Economics and Policy Program at RTI International. His research includes economic modeling of the agriculture and energy sectors in partial and general equilibrium frameworks.

Robert BeachRobert H. Beach, PhD, directs the Agriculture, Resource & Energy Economics and Policy (AREEP) Program at RTI International. His research includes developing and applying economic models to analyze agricultural, environmental, and natural resource regulations, programs, and policies.

Ross LoomisRoss J. Loomis, MS, is a senior economist in RTI’s Ecosystem Services Research Program. His research includes analyzing and modeling markets for ecosystem services; valuing nonmarket goods; and conducting benefit-cost and economic impact analyses, advanced statistical and spatial analyses, and industry assessments.

Michael GallaherMichael P. Gallaher, PhD, is the senior director of RTI’s Center for Environmental, Technology, and Energy Economics. His research includes R&D and environmental policy analysis, with a focus on evaluating new technologies and their associated economic and environmental impacts.

David DaytonDavid C. Dayton, PhD, manages the biofuels program in RTI’s Engineering and Technology Unit. His research focuses on alternative fuels research, particularly synthesis gas conversion, cleanup, and conditioning, and experimental programs related to biomass thermochemical conversion for biofuel production.

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