There are growing opportunities and demands for the use of biomass to provide additional renewables, energy for heat, power and fuel, pharmaceuticals and green chemical feedstocks. However, the worldwide potential of bioenergy is limited, because all land is multifunctional, and land is also needed for food, feed, timber and fiber production, and for nature conservation and climate protection. The recent expansion of the bioenergy industries together with a strong increase in many commodity prices has raised concerns over the land use choices between energy needs and food and feed. New systems of energy production must be developed based on cost of environmental damage due to production and use of fossil energy and certain chemicals and materials. This article presents risks to food and energy security, estimates of bioenergy potential and the challenges of the environmental and social impact associated with expansions in bioenergy production.