Current Methods for LCA of Low-Carbon Transportation Fuels in the United States (2022)

Greenhouse gas (GHG) emissions drive climate change. In the United States, transportation is the largest source of GHG emissions. Petroleum products account for about 90 percent of U.S. transportation fuels, with biofuels, natural gas, and electricity accounting for the rest. To mitigate further effects of climate change, deployment of low-carbon energy technologies, such as fuels with low GHG emissions, is considered to be critical.

There are federal and state programs to reduce GHG emissions from transportation fuels. The Renewable Fuel Standard (RFS) program, which is administered by the U.S. Environmental Protection Agency (EPA), was enacted by Congress in 2005 and amended in 2007. The program aims to reduce lifecycle GHG emissions from transportation fuels, expand the U.S. renewable fuels sector, and reduce reliance on imported oil. At the state level, California and Oregon have adopted low-carbon fuel standards (LCFSs). Recent reports from staff of the House Select Committee on the Climate Crisis and from a bipartisan network of former EPA career employees indicate interest in a national LCFS.