Megacity populationDespite 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 2022, New York, the largest city in North America, was the 11th 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 20 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, Dhaka in Bangladesh has the highest global population density, while Asia, by far, is the region with the highest population density.