This book, sponsored by the Stockholm Environment Institute, presents a detailed analysis of changes in world energy use over the past twenty years. It considers the future prospects of energy demand, and discusses ways of restraining growth in consumption in order to meet environmental and economic development goals. Based on a decade of research by the authors and their colleagues at Lawrence Berkeley Laboratory in collaboration with the Stockholm Environment Institute, it presents a wealth of information on energy use and the forces shaping it in the industrial, developing, and formerly planned economies. The book provides an invaluable overview of the potential for improving energy efficiency, and discusses the policies that could help realize the potential. While calling for strong action by governments and the private sector, the authors stress the importance of considering the full range of factors that will shape realization of the energy efficiency potential around the world.