Human development reached an important and challenging milestone in 2014. That year, the United Nations announced that more than half of the world’s population lived in urban areas. The news raised questions about issues such as disease control, food production, education, housing, employment, and migration.
Today, 55% of the global population is urbanized, and by 2030 the U.N. projects that 60% of the global population will be urbanized. In the nearly five years since the world discovered this global demographic shift, the number of megacities — defined as cities with populations greater than 10 million — grew from 28 in 2014 to 33 in 2018, more than triple the number in 1990.
To identify the world’s 33 megacities, 24/7 Wall St. used the U.N.’s data booklet, “The World’s Cities in 2018.” All data on population, population projections, and the percentage of a nation’s population residing in urban areas are from this source.
It is important to note that there are no standard global criteria for determining the boundaries of a city for the purpose of population studies. Some estimates look only at the population inside a city’s administrative boundaries, known as the “city proper” population. Other population measures include surrounding suburban communities that have economic ties to a nearby urban core but can stretch for hundreds of square miles through small farming communities and national parks.