The quantity of fossil fuels left on the planet is limited, and their use is subject to further restrictions due to constraints on CO2 emissions. This crisis has brought to the forefront of the political agenda the need for a conversion to a sustainable society. In this compelling book, a backcasting approach based on energy flows is used to evaluate the physical constraints on sustainable development. The starting point for the backcasting approach is the definition of a desired situation at a determined point in the future. This leads to the development of scenarios that connect our present status with the desired future point. This detailed, quantitative approach gives insights into the challenges that lie ahead in order to realise our goal. This book clearly displays large sets of expectations concerning the development of future population size and wealth, technological improvements and resource quantities. These are used to discuss the overall possibility for a transition to a sustainable society and highlight the dilemma between equity and environmental quality. A selection of other energy-scenario studies using different approaches are also discussed and contrasted with the backcasting model. The book concludes with some reflections on the institutional and socio-psychological aspects of a transition to sustainability and recommends a goal-oriented policy to implement this change. This book will prove essential reading for those with an interest in ecological economics, energy and environmental policymakers and research planners.