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MEGACITIES
source: www.unchs.org/mediacentre/
documents/backgrounder5.doc
www.citymayors.com/features/
urban_areas.html
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The United Nations (UN) coined the term 'megacities' in the 1970s to designate all urban agglomerations with 8 million or more inhabitants; the UN's present threshold for megacity status is 10 million… - megacities have captured public interest because cities this large are unprecedented in history, and because of the popular perception that human well-being will decline in such dense concentrations of people. Indeed, these are urban areas where the original core city has become part of an agglomeration that takes in neighbouring towns, new suburbs, dormitory towns or shanty settlements;
- megacities are becoming more and more numerous and will play an important role in the world's urban future. Many of the largest cities are likely to absorb enormous population increments: in 1950, there was only 1 city with a population of over 10 million inhabitants: New York. In 2000 there were 22 cities with a population of between 5 and 10 million; there were 402 cities with a population of 1 to 5 million; and 433 cities in the . 5 to 1 million category. By 2015, it is expected that there will be 23 cities with a population over 10 million;
- of the 23 cities expected to reach 10 million plus by 2015, 19 of them will be in developing countries. Among the cities that are projected to house more than 20 million by 2015 are Mumbai (formerly Bombay, India), Lagos (Nigeria), and São Paulo (Brazil);
- whereas London took 130 years to grow from 1 to 8 million, Bangkok took 45 years, Dhaka 37 years and Seoul only 25 years;
- by some measures, population growth appears to have slowed in megacities in recent decades. The UN estimates that average annual growth rates plummeted in Mexico City between the 1960s and the 1980s - from 5.1% to 0.9%. Annual population growth rates also slowed considerably in the megacities of São Paulo (from 5.4% to 1.9%), Calcutta, India (2.3% to 1.8%), and Beijing (2.6% to 1.8%) over the period. And in cities in more developed countries, annual growth rates fell from 1.3% to 0.3% in New York and from 4.1% to 1.7% in Tokyo between the 1960s and 1980s; (1)
- despite the slower pace of growth, cities in less developed countries are adding more new residents each year now than in the 1950s and 1960s because the growth rate is applied to an expanding population base. The average annual growth rate declined in Cairo, over the last 50 years. But Cairo added 4.6 million to its population between 1975 and 2000, about 1 million more than were added between 1950 and 1975. (1)
source: UN-Habitat, 2002 [ www.unhabitat.org]
(1) Martin P. Brockerhoff, “An Urbanizing World”, Population Bulletin, Vol. 55, No. 3, September 2000 [ www.prb.org]
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