The term ‘megacity’ refers to metropolitan areas with a total population of more than 10 million people. The definition of what constitutes a megacity generally refers to the population of an urban agglomeration, that is, it includes people living in the immediate suburbs outside of the established border of the city.
Megacities are a distinctly modern phenomenon, the proliferation of which has spread with the large-scale urbanisation that has occurred in many countries around the world. Whereas only 3% of the global population lived in cities in 1800, by the end of the 20th century that figure had risen to 47%. This figure is predicted to rise to more than 70% by the second half of the 21st century, a figure made even more startling by the fact that the human population is expected to have increased by two billion by that point.
Historically, the growth of megacities first emerged during the industrial revolution in which large numbers of the people moved to cities in order to find work, and it was broadly associated with developed nations. Contemporary megacity development is predominantly focused in areas of the world that are the least developed, such as Mumbai.
In 1950, the only megacities were New York-Newark and Tokyo. By 1995 the number had risen to 14. In 2016, there are 35, providing homes to 8% of the world’s population.
The 30 largest megacities, in ascending order, are:
- Tokyo-Yokohama, Japan – 37.9 million
- Jakarta, Indonesia – 30 million
- Seoul, South Korea – 26.1 million
- Delhi, India – 25.7 million
- Shanghai, China – 25.4 million
- Karachi, Pakistan – 24.3 million
- New York City, USA – 23.6 million
- Mexico City, Mexico – 22.2 million
- Beijing, China – 21.6 million
- Sao Paulo, Brazil – 21.2 million
- Lagos, Nigeria – 21 million
- Mumbai, India – 20.7 million
- Osaka, Japan – 20.2 million
- Manila, Philippines – 20 million
- Cairo, Egypt – 18.8 million
- Los Angeles, USA – 18.5 million
- Dhaka, Bangladesh – 18.2 million
- Moscow, Russia – 16.9 million
- Buenos Aires, Argentina – 16.5 million
- Bangkok, Thailand – 15.3 million
- Istanbul, Turkey – 14.8 million
- Kolkata, India – 14.7 million
- Rio de Janerio, Brazil – 14.4 million
- London, United Kingdom – 14 million
- Tehran, Iran – 13.7 million
- Guangzhou, China – 12.7 million
- Kinshasa, Democratic Republic of Congo – 12.5 million
- Shenzhen, China – 12.25 million
- Paris, France – 12 million
- Rhine-Ruhr, Germany – 11.3 million
 Related articles on Designing Buildings Wiki
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- Eco towns.
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- Global Construction Megacities 2017.
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 External references
National Geographic - The growth of megacities
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