Nearly 4,000 cities on our planet today have populations of 100,000 people or more. We know their names, locations, and approximate populations from maps and other data sources, but there is little comparable knowledge about all these cities, and none that can be described as rigorously scientific.
At a time when the world’s cities are bursting with massive increases in population, the Atlas of Urban Expansion is a comprehensive guide to the past and future characteristics of metropolitan growth. In 2010 more than half of the world’s total population lived in cities, and this share is expected to increase to 70 percent or more by 2050.
In a rapidly urbanizing world — over half the world’s population lives in urban areas, including many millions in informal settlement — the large cities of the developing world in particular are expanding. Yet there is little in the way of planning and preparation for this explosive growth in urban population.