The megalopolis cities in 2025

36 megalopolises in 2025

Keywords: cities, population, future, urbanization, megalopolis, environment

Today half of the Earth people live in megalopolises and, by 2050, they will be two thirds of the world population. Such is the alarming assessment drawn up by specialists in urbanization on the expansion of giant cities, during the forum urban development organized by UN-Habitat, which
was recently held in Barcelona.

A seemingly irreversible trend

Any city with a population of over 8 million can be referred to as a megalopolis. According to this definition, chosen by UNESCO, there were 23 in 1995 and there would be 36 in 2015. By then, still according to Unesco, their number will not vary in
industrialized countries. However, it will change from 17 to 30 in less developed regions.

For geographer Olivier Dollfus, these megalopolises are of two very different types depending on whether or not they belong to what he calls the AMM (World Megalopolitan Archipelago), a set of large cities that contribute to the direction of the world and are a strong symbol of globalization. The megalopolises are no longer only described by their number of inhabitants but by the functions they fulfill and their influence on the rest of the world. For example, 90% of global financial transactions are processed within a limited number of mega-cities in developed countries.

Megacities and the environment

It is no coincidence that certain terms designating precarious habitats are associated with the largest metropolises in poor countries. Among the best known in France, we can cite "favela", from Brazil, or "shantytown", a word that appeared in Casablanca in the 20s. We estimate between 20% and 30% the percentage of housing created in megalopolises and which belong to "informal construction" *.

It is for a large part in this type of habitat that the 2,5 billion humans live who do not have access to a water purification network. And the impact of large urban concentrations on water pollution can generally be measured far beyond their limits, especially downstream from the rivers that cross them.

Read also: The oil flow to 1998 2004

Air quality is another major issue for living conditions in megalopolises. Pollution does not always reach the heights that one might fear, but its impact is often very wide. Pollutants generated in large cities are likely to move and spread over long distances depending on the movement of the atmosphere. An air monitoring network in megalopolises was established in 1974, under the leadership of the WHO (World Health Organization) and the UNEP (United Nations Environment Program). It makes it possible to verify that the thresholds of concern for public health are often exceeded there.

* source: United Nations Habitat II Conference, Istanbul, 1996

Philippe Dorison

List of megalopolises in 2025
In millions of inhabitants

TOKYO - 28,9
BOMBAY - 26,3
LAGOS - 24,6
SAO POLO - 20,3
DACCA - 19,5
KARACHI - 19,4
MEXICO - 19,2
SHANGAI - 18,0
NEW YORK - 17,6
CALCUTTA - 17,3
DEHLI - 16,9
BEIJING - 15,6
MANILA - 14,7
CAIRO - 14,4
LOS ANGELES - 14,2
BUENOS AIRES - 13,9
DJAKARTA - 13,9
TIANJIN - 13,5
SEOUL - 13,0
ISTAMBUL - 12,3
RIO DE JANEIRO - 11,9
HANGZOU - 11,4
OSAKA - 10,6
HYDERABAD - 10,5
TEHERAN - 10,3
LAHORE - 10
BANGKOK - 9,8
PARIS - 9,7
KINSHASA - 9,4
LIMA - 9,4
MOSCOW - 9,3
MADRAS - 9,1
CHANGCHUN - 8,9
BOGOTA - 8,4
HARBIN - 8,1
BANGALORE - 8,0

Leave a comment

Your email address will not be published. Required fields are marked with *