Half of mankind lives in cities and the tendency is on the increase. These people use the greater part of our energy and yet also produce the most pollutants â€“ with far-reaching consequences for the world climate. The other way around, climate change has an impact on urban life, influencing living conditions in the city. These tremendous changes herald the departure into a new age. The International Building Exhibition Hamburg focuses on this theme, taking a detailed look at "The City in Climate Change". Volume 2 of the series "Metropolis" 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.