In 1950 New York was the only such area; there are currently (2002) twenty, with twelve of those areas having exceeded 10 million since 1990. This has happened as the entire world population moves towards the high (75-85%) urbanization levels of North America and Western Europe. It is not clear that any city exclusive of its suburbs exceeds 10 million.
The known megacities are:
As well as all these cities experiencing some growth, by 2015 there could be a further six megacities. However the expansion of megalopolis[?] is probably a greater trend, such as the previously mentioned Tokyo-Osaka, or Baltimore-Washington or Rio de Janeiro-Sao Paulo.
See also Largest cities of the world.
In the comic 2000 A.D., the fictional Megacity One[?] is a megalopolis of 800 million people across the east coast of the United States, policed by Judge Dredd.
In Canada, megacity refers to the results of having merged the suburbs of an urban region into one large municipality. Cities so merged include Winnipeg, Manitoba (this merger antedates the term, and was called "Unicity" at the time); Toronto, Ontario; Montreal, Quebec; Gatineau, Quebec; Longueuil, Quebec; Quebec City, Quebec; and Saguenay, Quebec.
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