It’s the age of the city. Today more than half the world’s population can be found in cities, and megacities—those with populations of 10 million or more—are on the rise. The world’s largest megacity, Tokyo-Yokohama, joins two cities and multiple Japanese prefectures to cover 5,200 square miles, and it houses a population of some 37.5 million individuals.
For many people, cities offer economic, educational or social opportunities not available in smaller, rural environs. Urban lifestyles can also have environmental advantages when public transportation replaces long trips in gas-guzzlers and residents are tucked into smaller, more efficient housing.