By 2030 more than 60% of all people will live in cities, and most of this growth will occur in developing countries where financial resources and the capacity needed to cope with this challenge are limited. Health, shelter, and food security crises are looming large in many of these cities, as are growing pressures and conflicts over access to the natural resources of the hinterland. At the same time, urban areas are increasingly recognized for their environmental values and diversity. Scientific interest in urban ecology is growing, and stakeholders all over the world are claiming the right to be recognized as stewards of their environment through devolution of power. In this context, a clear need exists for innovative governance approaches that deal with the complexities of urban sustainability while reflecting the cultural diversity of today's large cities. This volume examines challenges and opportunities for urban sustainability around the world.