Impacts of a 32-billion-gallon bioenergy landscape on land and fossil fuel use in the US

Sustainable transportation biofuels may require considerable changes in land use to meet mandated targets. Understanding the possible impact of di erent policies on land use and greenhouse gas emissions has typically proceeded by exploring either ecosystem or economic modelling. Here we integrate such models to assess the potential for the US Renewable Fuel Standard to reduce greenhouse gas emissions from the transportation sector through the use of cellulosic biofuels. We find that 2022 US emissions are decreased by 7.0± 2.5% largely through gasoline displacement and soil carbon storage by perennial grasses. If the Renewable Fuel Standard is accompanied by a cellulosic biofuel tax credit, these emissions could be reduced by 12.3± 3.4%. Our integrated approach indicates that transitioning to cellulosic biofuels canmeet a 32-billion-gallon Renewable Fuel Standard target with negligible e ects on food crop production, while reducing fossil fuel use and greenhouse gas emissions. However, emissions savings are lower than previous estimates that did not account for economic constraints.