Sixty percent of the global population will live in cities by 2030, with 90% of urban growth in coming decades likely to occur in low- and middle-income countries. Current urbanization trends indicate that an additional three billion people will be living in cities by 2050, increasing the urban share of the world’s population to two-thirds. 95% of the growth in urban areas in the next two decades will occur in cities, making them home to more than 4 billion people, translating to about 80% of the future urban population.

The steady trend towards urbanization will influence every facet of human endeavor in the coming years, including health, economic, social, and environmental. In many parts of the world, especially in developing countries, high rates of urbanization have unfolded in the context of stagnating economies and poor planning and governance, creating a new face of abject poverty concentrated in slums or informal settlements in major cities. Indeed, the unprecedented proliferation of slums and informal settlements in the world especially in developing countries, and a chronic lack of adequate housing, continue to be among the major challenges of urbanization today. Slums, informal settlements, and inadequate housing remain the visible manifestations of poverty and inequality in cities.