Trends Important in Understanding the problems and Challenges of Urban Growth

Several trends are important in understanding the problems and challenges of urban growth. First, the global proportion of urban population rose dramatically from 13%  in 1900, to 29% in 1950, to 49% in 2005.  

According to UN projections, by 2050 over 6 billion people, two thirds of humanity, will be living in towns and cities, with 93% of this urban growth occurring in developing countries.

Second, the number of large cities is mushrooming. In 1900, only 19 cities had a million or more people, and more than 95% of humanity lived in rural communities. In 2003, more than 400 cities had a million or more people (projected to increase to 564 by 2015). Also there were 19 megacities (up from 8 in 1985) with 10 million or more people—most of them in developing countries.

 As they grow and sprawl outward, separate urban areas may merge to form a megalopolis.

A third trend is that urbanization and the urban population is increasing rapidly in developing countries. Currently, about 40% of the people in developing countries live in urban areas.

Fourth, urban growth is much slower in developed countries (with 75% urbanization) than in developing countries. Still, developed countries are projected to reach 84% urbanization by 2025.

Finally, poverty is becoming increasingly urbanized as more poor people migrate from rural to urban areas. The UN estimates that at least 1 billion people live in crowded slums of central cities and in squatter settlements and shantytowns that surrounds the outskirts of most cities in developing countries.

Fig: Centre of Sao Paulo, one of the largest metropolises in the world.