At the Rio+20 Earth Summit in June, Curitiba won a Global Green City Award, and UN Secretary-General Ban Ki-moon called it a model of sustainable development. How has it won such acclaim?
 

In the 1970s, an idealistic architect and urban planner named Jaime Lerner became mayor of Curitiba, Brazil, and employed a "culture of speed" to give his city a facelift.
 

No longer content to measure success in terms of cargo shipments, Kaohsiung is expanding green spaces and opening arts districts, to remake itself as a "great city to live in."

Cities are rushing to reinvent themselves to get an edge, but San Francisco's 40-year revitalization program proves that time is a necessary cost of urban renewal.

San Francisco's first Chinese-American mayor Edwin M. Lee has been on board throughout the city's long process of urban renewal. In this exclusive interview, he explains how people, not government, ultimately drive success.