London was the largest city in the world in 1850, the second largest in 1950 but only the twenty-seventh largest in 2000. Only one of the five largest cities in 2000 was in the North America: Mexico City at about 26 million followed by Sao Paolo, Tokyo, Calcutta, Bombay, New York, Seoul, Shanghai, Rio de Janeiro and Delhi. Guessing at the dates of the first cities, one could estimate that it took about 10,000 years before as many people lived in cities as in the country (England in about 1850); since then it has taken just over 150 years for that to be true for the whole world. The rate of urban growth and the size of the largest cities is, with few historical exceptions, unprecedented, as is the percentage of these populations who remain in poverty. The United Nations estimates that a quarter of urban dwellers live as squatters in developing countries. Half of the world's population lives on less than two dollars a day, one out of four do not have clean water, and 40,000 children die every day because of hunger-related diseases. In 1960 the wealthiest 20% of the world's population earned 30 times more than the bottom fifth; now they earn 74% more. In this light it is difficult any longer to talk about cities in the classical language of urban social science or city planning. Much of the thought about these cities has been about urban survival, public health, the possibility of securing stable land and housing, and about education for children to move beyond poverty. There have been few plans for major changes to the form of the city, Bombay's building of a large new component to the city, New Bombay, is among the few. How these cities can become sufficiently powerful economic engines, as they became in nineteenth-century Europe, and how they can distribute wealth is the task of this century. Yet the challenge seems to be recruiting only a very few of the world's urbanists.
From many of these countries, the idea of building new capital cities after independence has meant added national pride but little help for the problems of their large cities. New capitals since 1950 include Nonakchott, Dodoma and Abuja in Africa, Chandigarh and Islamabad in the East, and Brasilia in Latin America. Of these, the forms of Brasilia and Chandigarh have attracted the most attention. With 80% of Brazilians living within 200 miles of the Atlantic, Brasilia promised to open up its Amazonian heartland. Brasilia was built as the center of a federation of existing settlements and workers' camps; in 1973 Brasilia constituted less than a third of the federal district's population. It has not alleviated many of the problems of Brazil's large cities: in 1970 Brasilia's total population was the same as the annual population increment of Sao Paolo. Chandigarh was built in 1959 as the capital of the Punjab (which it never has been) after the India / Pakistan partition. Planned by Le Corbusier, it took the form of repeated residential sectors, five types of wide roads and a capitol complex at the northern end of the city. Fifty years later, Chandigarh is much larger than the Corbusian plan imagined, largely through immigrants migrating from rural poverty to a new center of employment, Chandigarh itself has been surrounded on the south and east by unplanned towns, making Chandigarh the planned center of a random metropolitan area, much as the historic center of an Italian city is surrounded by a loosely organized periphery. The city has virtually no system of public transport, and is hierarchically organized from rich bungalows in the north to the denser housing for the poor further south. For political reasons the capitol complex, now serving two states, is guarded by military personnel. There is no drive to achieve a metropolitan plan, and Chandigarh still tries to conform to the dated policies of its origin while the rest of the metropolitan area—in whole to reach about two million in the next decade—grows freely all around.
Brooke, James. "The World; Feeding on 19th Century Conditions, Cholera Spreads in Latin America," The New York Times, April 21, 1991.
Hackley, Randall. "A lovely madness—Argentina builds new capital in Patagonia."
Peirce, Neal R., and Curtis W. Johnson. "Current and Projected Number of Slum Dwellers, by Region" and Chapter 1 in Century of the City: No Time to Lose. Rockefeller Foundation, 2008. ISBN: 9780891840725.