Einar H. Dyvik
Research expert covering Nordics and global data for society, economy, and politics
Global megacities - Statistics & Facts
As the global population reached eight billion people, more and more people live in cities and suburbs. While big cities offer vast employment and social opportunities, megacities are struggling with several challenges around the world; poverty, crime, pollution, transport, and waste management are just some of the issues the largest cities in the world are facing. Will megacities continue to grow into the unforeseeable future, or soon reach their limits?
Megacities have been defined by the United Nations as cities with more than 10 million inhabitants. The way of measuring the total population of cities and urban areas varies, as some only count the population size in a specific commune or county, whereas other include suburbs. While, Tokyo usually is defined as the largest city in the world by number of inhabitants, looking only at administrative areas, Chongqing in China is considered to be the largest city worldwide, but its administrative boundaries stretch way beyond the city and includes a high number of people living in rural areas.
Population density also varies from country to country and from city to city. Unsurprisingly, some of the smallest states by area and the word's city-states have the highest population densities globally. Looking away from these, Mogadishu in Somalia has the highest global population density, while Asia, by far, is the region with the highest population density.
Megacities have been defined by the United Nations as cities with more than 10 million inhabitants. The way of measuring the total population of cities and urban areas varies, as some only count the population size in a specific commune or county, whereas other include suburbs. While, Tokyo usually is defined as the largest city in the world by number of inhabitants, looking only at administrative areas, Chongqing in China is considered to be the largest city worldwide, but its administrative boundaries stretch way beyond the city and includes a high number of people living in rural areas.
The growth of megacities
Despite varying definitions of urban populations, there is no doubt that city populations have been growing throughout the 20th and 21st centuries. The number of people living in urban areas with 10 million inhabitants or more has rocketed from less than 70 million in 1975 to nearly 463 million in 2015. Whereas North America is the region with the highest degree of urbanization, none of its cities rank among the 10 largest in the world. As of 2023, New York, the largest city in North America, was the 13th most populous in the world. Furthermore, a majority of the areas with a population of 500,000 inhabitants or more are located in Asia, with China accounting for more than 25 percent of the cities worldwide of this size.Population density also varies from country to country and from city to city. Unsurprisingly, some of the smallest states by area and the word's city-states have the highest population densities globally. Looking away from these, Mogadishu in Somalia has the highest global population density, while Asia, by far, is the region with the highest population density.
Pros and cons of life in megacities
Megacities present various opportunities for its citizens, including access to education, a diversified job market and higher salaries, different means of transport, interconnectivity, as well as various social activities and events. Nevertheless, the higher salaries and opportunities come at a price. Some megacities face extreme costs of living, with New York and Singapore being the most expensive cities to live in worldwide. Some experts have even started to speak of some cities as being only livable for the rich. Furthermore, many increasingly concentrated urban areas are noisy, and are often marked by slums and high crime rates. Slums and a lack of a proper transportation system are particularly problems in developing countries where income inequalities tend to be high, and where public authorities struggle to keep up with the tempo of the fast growing cities. As the world's population is expected to continue to grow at a rapid pace over the coming decades, these challenges are likely to continue to increase.
