Renewable and low-carbon fuel standards, such as the Federal Renewable Fuel Standard and the California Low Carbon Fuel Standard, are major U.S. programs for reducing greenhouse gas emissions from transportation fuels. These standards rely on life cycle assessment as a method to estimate fuel greenhouse gas emissions. However, current life cycle assessments differ notably in how they are implemented, with disagreements pertaining to data quality, modeling approaches, and key assumptions. Now, a National Academies of Sciences, Engineering, and Medicine (NASEM) committee will study Current Methods for Life Cycle Analyses of Low-Carbon Transportation Fuels in the United States. Professor Valerie Thomas, Anderson-Interface Chair of Natural Systems in the H. Milton Stewart School of Industrial and Systems Engineering, has been appointed to chair the committee, which will meet through April 2022 to do its work.

Thomas, who holds a joint appointment in Georgia Tech’s School of Public Policy, is an expert in life cycle assessment, sustainability, and science and technology policy. Her current research projects include life cycle assessment of biofuels made from algae, of carbon dioxide captured from air, of chemicals made from biomass, and of alternative technologies for conventional and urban agriculture. 

Under Thomas’ leadership, the committee will consider direct and indirect greenhouse gas emissions; that is, direct greenhouse gas emissions from producing feedstock for fuel and making and using the fuel, and emissions from indirect effects such as land use change. Indirect effects can occur, for example, when land used for one purpose – such as growing corn for food – instead is used to grow feedstock for biofuel. 

The committee will also consider key assumptions and the quality of the data used to estimate greenhouse gas emissions, and may assess needs for additional data and model development. The group also will consider methods used to evaluate biofuels, electricity as a transportation fuel, hydrogen fuels, low-carbon diesel fuels, and aviation and maritime fuels, among others.

“Transportation is a major source of greenhouse gas emissions, and multiple alternative-fuel technologies are being developed to address this challenging problem,” said Thomas. “Our committee has been tasked with providing recommendations for potential use in a national low-carbon fuels program. Our aim is to provide policy makers and the public with a robust, useful set of findings on the state-of-the-science in evaluating greenhouse gas emissions of low-carbon transportation fuels.”