via Nat’l Geographic: The Growth of Megacities

Geography in the News: The Growth of Megacities

Posted by Neal Lineback of Geography in the NewsTM on February 17, 2014
By Neal Lineback and Mandy Lineback Gritzner,  Geography in the NewsTM

Megacities’ Expansive Growth

For the first time in human history, more of the world’s 6.8 billion people live in cities than in rural areas. That is an incredible demographic and geographic shift since 1950 when only 30 percent of the world’s 2.5 billion inhabitants lived in urban environments.

The world’s largest cities, particularly in developing countries, are growing at phenomenal rates. As a growing landless class is attracted by urban opportunities, meager as they might be, these cities’ populations are ballooning to incredible numbers.

A May 2010 Christian Science Monitor article on “megacities” predicted that by 2050, almost 70 percent of the world’s estimated 10 billion people—more than the number of people living today—will reside in urban areas. The social, economic and environmental problems associated with a predominantly urbanized population are considerably different from those of the mostly rural world population of the past.

A megacity is an urban agglomeration (accumulation) with more than 10 million inhabitants. Sixty years ago in 1950, there were only two megacities—New York-Newark and Tokyo. In 1995, 14 megacities existed. Today, there are 22, mostly in the developing countries of Asia, Africa and Latin America. By 2025, there will probably be 30 or more.


Urbanization has been occurring in the developed countries of the West for 200 years. Since the Industrial Revolution, a period from the 18th to 19th century in which machine-based manufacturing grew tremendously, cities have grown rapidly. As technological innovations flourished, economies previously dependent on manual labor and draft-animals began to change. People moved into the cities to find work and relatively quickly, cities began to grow exponentially.

Today, the most rapid megacity growth is occurring in the world’s least developed and poorest countries—those least able to handle the political, social, economic and environmental problems associated with rapid urbanization.

In the most modern industrialized countries, on average, three out of four people already live within an urban area. In contrast, in the least-developed regions of the world, more than two out of three people still reside in a rural area. But that statistic is changing rapidly.

For people in developing countries, even the slums of cities like Mumbai, India, can offer more opportunities than their poor subsistence-based villages can. People gravitate to the cities because the potential for making money is greater there. While most of the economies in rural areas are agriculture-based with little cash flow, in the cities, people may be able to earn cash for work or retail sales.

The 10 largest cities in the world in 2010 and their projected populations by year 2025 are Tokyo, Japan  (37.1 million), Delhi, India (28.6), São Paulo, Brazil (21.7), Mumbai, India (25.8), Mexico City (20.7), New York-Newark (20.6), Shanghai, China (20.0), Calcutta, India (20.1), Dhaka, Bangladesh (20.9) and Karachi, Pakistan (18.7).

According to the Christian Science Monitor, along with the masses come problems associated with providing necessary services like clean water, sanitation systems to remove the megatons of garbage and human waste and transportation systems to ferry workers. In addition, many cities have difficult times providing electrical networks, health care facilities and police protection.

Urbanization is not all bad news. According to the Christian Science Monitor, some see great promise in the trend, especially those companies that build roads and buildings.  If a city is efficient, energy consumption can decrease by 20 percent. Transportation costs for goods and labor can fall considerably in cities because markets and workers are all close together. In essence, cities are where cash flows—they are where economic growth takes place.

As the world’s population increases at the rate of 134 million per year, the urbanization process is pushing more and more people into the cities. Such frenetic rates of urbanization and intense poverty of large urban populations strain resources. Nonetheless, to poverty-stricken, landless people, cities offer visions of opportunity. The resulting massive urban underclass, particularly in developing countries, represents one of the world’s greatest social and economic challenges.

The real question is, “What are the limits to urban growth?”

And that is Geography in the News.

Sources: GITN #1049, “Growing Megacities,” June 28, 2010; GITN #844, “Megacities: 10 Million or More People,” Aug. 4, 2006; and Bruinius, Harry, “March of the Megacities,” The Christian Science Monitor, May 10, 2010.

Co-authors are Neal Lineback, Appalachian State University Professor Emeritus of Geography, and Geographer Mandy Lineback Gritzner. University News Director Jane Nicholson serves as technical editor. Geography in the NewsTM  is solely owned and operated by Neal Lineback for the purpose of providing geographic education to readers worldwide.