Half of mankind lives in cities, and the tendency is on the increase. Urban people use the greater part of the world's energy and yet also produce the most pollutants--with far-reaching consequences for the world climate. Looking at this phenomenon the other way around, climate change has an impact on urban life and influences living conditions in the city. These tremendous changes herald the departure into a new age. The 2010 International Building Exhibition, IBA Hamburg, focuses on this theme, taking a detailed look at cities and climate change. This second volume in the Metropolis series illuminates causes and examines previous efforts in architecture, town planning and urban-development planning with the intention of reflecting on strategies and visions for a new, appropriate form of urban living.