Scientific American, September 2011

In this issue:

"Street Savvy": Meeting the biggest challenge starts with the city.

"The Social Nexus": The best way to harness a city’s potential for creativity and innovation.

"Global Bazaar": Today’s street markets and shantytowns are forging the world’s urban future.

"Castles in the Air": Why building skyscrapers makes sense on many levels.

"How Green Is My City": Why retrofitting is the best way to clean up urban living.