04/02/2008 12:21 pm ET Updated Nov 17, 2011

Supercities Taking Over

In 1800 less than three percent of the world lived in cities. Today over three billion people live in urban areas--more than half of the world's population! According to Richard Saul Wurman, in the 21st century there are currently 19 cities across the globe that are home to 20 million people. Wurman and his partners are conducting a five-year study into these "supercities" analyzing everything from growth patterns, crime dynamics, calamity risk and energy consumption and distribution. The results will be available on their web site (as well as through several other media outlets) and will undoubtedly be a valuable resource for all of us who live and work in cities--and travel frequently to other cities. reminds us that the world is no longer a collection of countries, but has instead become a series of urban centers that we can hop between fairly effortlessly through advances in technology and transportation. The site notes that we no longer say that we're going to England, China or Egypt--it's now London, Beijing and Cairo. also points out the ways in which this extreme urban living influences key elements of our lives such as shipping, food supply and--of most pressing environmental importance--meteorological patterns. Almost all of the 19 cities in question--from Los Angeles to Lagos--can be found next to an ocean, which means that over 50 percent of the earth's inhabitants will be directly affected by the rise in sea levels brought on by global warming (there's really no better time to go green).

Wurman gives us a lot to consider as we move about our respective metropolises.