Two of the most important challenges facing those alive today are smoothly navigating a transition from reliance on resource capital to reliance on resource income, and alleviating poverty. Transformative changes in energy supply will be required to address both of these challenges, with the “second half “ of low carbon electricity and transportation supply particularly difficult to achieve. Although controversial, many foresee that energy from plant biomass will be needed to address these interlinked challenges.

Perspectives and recent research will be presented on the need for bioenergy and biofuels on a scale sufficient to offer meaningful mitigation benefits, low carbon bioenergy supply chains and related accounting issues, and the role of bioenergy in human development. A particular focus will be a comprehensive, not-yet-published analysis of the circumstances under which celllulosic biofuels result in greenhouse gas emission (GHGE) benefits, including comparison to unharvested regrowth and land sparing through health-promoting dietary changes. Using a common analytical framework applied to the United States, we show that biofuels can offer much larger, comparable or much smaller GHGE benefits compared to unharvested land, depending on the initial land cover, the land cover that would develop without harvest, feedstock and fuel production technology, and whether carbon capture and storage is employed. Indirect land use change is considered but has a relatively small impact. Biofuel production on US land spared by diets featuring lower beef consumption could approach total domestic transport energy use while providing large GHGE benefits.