Mega-citiesIn 1950, New York was the only city with more than 10 million inhabitants. There are now 11cities housing over 11 million people each. Tokyo alone has 17 million. In 1995, their combined population totaled 166 million; in 2015 it is forecast to be over 204 million.The worlds urban population, increasing at four times the rate of rural populations, will double in the period 1990-2025, to over five billion. Consequently, two-thirds of the people of the world will live in cities, so
