Biomass offers an alternative renewable energy source to fossil fuels and can be used to produce energy directly or through the production of liquid biofuels, e.g., ethanol, as a substitute for liquid transport fuels. Biomass also offers a vehicle to sequester carbon dioxide, thereby reducing atmospheric carbon, which contributes to global warming. However, in some cases, e.g., forests, there is a tension between biomass energy and biomass sequestration of carbon. This paper focuses on both energy and carbon sequestration issues with a view to a better understanding of the potential role of biomass in energy and climate.