A megacity is usually defined as a metropolitan area with a total population in excess of 10 million people. A megacity can be a single metropolitan area or two or more metropolitan areas that converge. The terms conurbation, metropolis, and metroplex are also applied to the latter.
As of 2015, there are 35 megacities in existence.
The largest of these are the metropolitan areas of Tokyo and Shanghai, each of these having a population of over 30 million inhabitants, with 38.8 million and 35.5 million respectively.
The largest of these are the metropolitan areas of Tokyo and Shanghai, each of these having a population of over 30 million inhabitants, with 38.8 million and 35.5 million respectively.
The UN predicts there will be 41 megacities by 2030. (wikipedia, 2016-10-2)
Since the mid-twentieth century human action has become the most important factor governing crucial biogeochemical cycles, to wit, the carbon cycle, the sulfur cycle, and the nitrogen cycle.
Only one in twelve persons now alive can remember anything before 1945.
Since the mid-twentieth century human action has become the most important factor governing crucial biogeochemical cycles, to wit, the carbon cycle, the sulfur cycle, and the nitrogen cycle.
Only one in twelve persons now alive can remember anything before 1945.
Before 1800 only a very small number of cities had ever approached a million inhabitants.
There were some basic reasons why there were few large cities, and few cities at all, for that matter, before the modern period.
They were like big carnivores in the ecosystem: they drew their sustenance
from over a large space and therefore could only be few in number.
In 2008 demographers at the UN announced that >50% of humans were living in cities.
29% in 1950 (730 million people)
slightly more than half in 2015 (roughly 3.7 billion people)
This is one of the signal characteristics of the Anthropocene: the majority of
humankind are now living within environments of its own creation.
Our species has become, in effect, an urban animal.
29% in 1950 (730 million people)
slightly more than half in 2015 (roughly 3.7 billion people)
This is one of the signal characteristics of the Anthropocene: the majority of
humankind are now living within environments of its own creation.
Our species has become, in effect, an urban animal.
The world today has 500 cities of populations of at least one million people, 74 with at least 5 million, and 12 with at least 20 million. (The Great Acceleration: An Environmental History of the Anthropocene since 1945, by J. R. McNeill and Peter Engelke, 2014, preface & Chap 3)
