Most people will live in cities by 2050

India, China and Nigeria will account for 35% of the growth

UNITED NATIONS - Today, 55 percent of the world's population live in urban areas, a proportion that is expected to increase to 68 percent by 2050, the United Nations said on Wednesday.

Projections show that urbanization, the gradual shift of people from rural to urban areas, combined with the overall growth of the world's population, could add another 2.5 billion people to urban areas by 2050, with close to 90 percent of this increase taking place in Asia and Africa, according to new UN data released on Wednesday.