Urbanization doubtlessly has been the most significant demographic trend in the world for at least a century and promises to become even more significant in the future. The trend began in the United States and Western Europe as people moved by the millions from the countryside to the urban areas, where employment and a better life were possible.
World Urbanization: By 1950, approximately 30% of the world’s population lived in urban areas (that is they did not live in rural areas). The number has passed 50% in the last few years and the United Nations estimates that 60% of the population will live in urban areas by 2030. Today, China has approximately the same urban population share as did the United States 100 years ago (45%), and will reach 60% by 2030. Even with its slow population growth, China will add 270 million people to its urban areas by 2030. Only 30% of India’s population is urban, which will increase to 40% by 2030. This apparently modest increase will amount to 250 million new urban residents. Thus, combined, China and India will add about 60% more population to their urban areas than live in the United States today.
As late as 1950, 10 of the world’s 20 largest urban areas were in the United States or Europe. Asia accounted for 6. There was only two “megacities” (urban area with a population of more than 10 million), New York and Tokyo. Over the next 50 years, Tokyo signaled the urban ascendancy of Asia, adding more than 20 million people, a larger population than lived in the second largest urban area in 2000.
Demographia World Urban Areas: The continuing Asian urban ascendancy is illustrated in our 6th Annual Edition of Demographia World Urban Areas. This list includes all identified urban areas (Note) in the world with more than 500,000 population, and, unlike other lists estimates the urban land area and population density of each.
Things have changed markedly since 1950. Now, 13 of the 20 largest urban areas in the world are in Asia. Only three are in the United States or Europe (New York, Los Angeles and Moscow). For the first time in at least 200 years, none of the top 5 urban areas in the world are in the United States or Europe. Now, all five of the largest urban areas in the world are in Asia. There are now 26 megacities, up from 2 in 1950. At current growth rates, there could be 39 megacities by 2030, only five of which will be in the United States or Europe (New York, Los Angeles, Moscow, Paris and Chicago)
Tokyo remains the largest urban area (35.2 million) in the world, far larger than any other. Yet, with a slow growth rate, Tokyo is predicted to increase to only 36.0 million by 2030 and could be displaced by Jakarta.
Jakarta is estimated to be the world’s second largest urban area, with 22.0 million people. This is a larger population than indicated on some lists, which fail to include all of the suburbs within the urban footprint. At currently projected growth rates, Jakarta could edge out Tokyo to become the largest urban area in the world by 2030, at 37.0 million. Jakarta is also unique in having adopted an official metropolitan area name, Jabotabek (taken from JAkarta, along with the large suburban municipalities of BOgor, TAngerang and BEKasi).
Mumbai ranks third with a population of 21.3 million. Some demographers expect that Mumbai could become the largest urban area in the world eventually. The trends suggest that it will not even prevail as India’s largest urban area, falling to fifth in the world, behind Delhi. Currently projected growth rates indicate a population of 31.4 million by 2030.
Delhi is the fourth largest urban area, with a population of 21.0 million. Like Jakarta, Delhi’s population is often under-estimated by limiting its urbanization to the National Capital Territory. However, the large, adjacent suburbs of Faridibad, Ghaziabad and Nodia add considerably to estimates. At projected growth rates, Delhi could have 32.8 million people by 2030 and be ranked as the fourth largest urban area in the world.
Manila ranks fifth and is another urban area often characterized as having a smaller population than the reality. Various lists confine Manila to the National Capital District, which has about 11 million people. This is rather like thinking of the Toronto area as confined within the city limits of Toronto, missing half of the urban area population. In fact, the urban organism in Manila (and Toronto) extends to where the rural areas begin, and that gives Manila a population of 20.8 million. The currently projected growth rate indicates that Manila could reach 34.1 million by 2030, to rank third in the world.
Predictions are Just Predictions: Of course projections are speculative and often do not come true. Before the 1985 earthquake, for example, many demographers expected Mexico City to become the largest urban area in the world. Since that time, Mexico City has grown, but not at the spectacular rate that was expected. In 1985, Mexico City was the third largest urban area in the world. Today Mexico City ranks 9th and could fall to 12th by 2030.
New York, which had been the perennial leader from early in the 20th century to 1950, fell to 6th place in 2010 and looks likely to fall further, to 10th in 2030. London, which had led the world from the early 19th century until New York assumed the top position, fell from 3rd place in 1950, to 29th in 2010 and could fall to 46th by 2030.
Urban Land Area: Housing and serving 10 million or more people takes a lot of space. The New York urban area covers the largest land area in the world, at 4,300 square miles (11,300 square kilometers), followed by Tokyo (3,400/8,700), Chicago (2,300/6,000), Los Angeles (2,200/5,800) and Boston (2,100/5,500). Another 17 urban areas cover more than 1,000 square miles or 2,500 square kilometers (such as Paris, Sao Paulo, Mexico City and Buenos Aires).
Urban Density: Dhaka, the capital of Bangladesh, has been growing very rapidly and especially its high-density slum or shanty town population, which can reach densities as high as 2,500,000 per square mile (1,000,000 per square kilometer). Dhaka is estimated to be the densest urban area in the world, with more than 100,000 people per square mile (40,000 per square kilometer). The “historical accident” city-states of Hong Kong and Macao are in a virtual three way tie with Mumbai (65,000/25,000), followed by Surat (India) at 55,000/21,000. The highest US urban area density is in Los Angeles, at 6,400/2,500; while Western Europe’s highest urban area density is in Madrid, at 14,100/5,400.
Of course, as the Dhaka case indicates, average densities can mask huge variations. The differences in density (density gradients) tend to be the greatest in developing world urban areas, where shantytown densities can be substantially greater than the Lower East Side of New York in 1910. However, average urban densities are the appropriate overall density measure for the urban organism, which includes everything from the core of the urban area, through the suburbs, ending at the countryside.
Of Urbanization and Aspiration: Much has been written about the challenges of urbanization and it is clear they are accelerating. UN estimates indicate that virtually all of the population increase in the world will be in urban areas between 2010 and 2030. There is a simple reason for this. The urban areas are far better places to live, even for low income people, than rural areas. This is because urban areas have strong economies. If conditions were better outside the urban areas, then the millions who have migrated to the favelas of Rio de Janeiro and Sao Paulo would long since have returned to their roots in northeastern Brazil. Jakarta and Karachi would be emptying out. Urban areas will continue to grow strongly, because people are driven by their aspirations, which are far better served in the urban areas.
Note: An urban area is an urban agglomeration or an urban footprint (area of continuous development). An urban area is the organism of the “city” in its spatial dimension. A metropolitan area is the organism of a city in its economic dimension and includes labor market areas that extend beyond the urban area. Census authorities in a number of nations have adopted similar definitions for urban areas (Examples are United States, Canada, United Kingdom, France, Norway, Sweden and Australia). Demographia World Urban Areas uses national census bureau data for both population and land area estimates where it is available and estimates urban land area from satellite imagery for all others, applying the international urban area criteria to the greatest possible extent.
Photograph: Suburban Manila
Wendell Cox is a Visiting Professor, Conservatoire National des Arts et Metiers, Paris. He was born in Los Angeles and was appointed to three terms on the Los Angeles County Transportation Commission by Mayor Tom Bradley. He is the author of "War on the Dream: How Anti-Sprawl Policy Threatens the Quality of Life.”