Massive urban growth can either help pave the way to sustainable development or greatly exacerbate poverty and environmental stress. The outcome depends on decisions being made now. The first part of this book takes a critical look at the forecasting of population growth and migration using the UN Population Division’s cities databases. The second part looks specifically at urbanization and poverty, focusing attention on the critical issues of urban shelter, land and service provision and the socioeconomic and demographic information needed for improving governance and social programs. Part three looks at social difference, equity and urban demography, pointing out the potential advantages of urbanization for poverty reduction, the empowerment of women and youths, and even the reduction of HIV/AIDS. The final part of the book examines social and sustainable use of urban space including coping with urban expansion, urban sprawl, global environmental change and urbanization. There is also special treatment of China, and the critical case of urbanization in low elevation coastal zones in the context of global climate change and rising sea levels.