|For the first time in history, more than half of the world’s people live in cities.|
Nearly 2,000,000,000 new urban residents are expected in the next 20 years.
|of global GDP is created by cities.|
|The proportion of the urban population in developing countries living in slums.|
Three largest cities in the world ranked by population
|New York City, USA
| São Paulo, Brazil
Sources: citymayors.com, UN-HABITAT State of the World’s Cities Report 2010/2011, The World Bank’s World Development Report 2009.