Are we transforming the planet into one massive global city? Urban migration and the rapid growth of cities are creating global change at a revolutionary scale. We are facing global crises like climate change, epidemics, widening poverty and terrorism. Jeb Brugmann draws on more than twenty years of experience working at the cutting edge of international urban issues to show how the city is now a medium for revolutionary change. Not just political upheaval but technological, economic and social innovations are forged in our cities. Brugmann shows how they are becoming laboratories for solving the major challenges of the 21st century: poverty, inequality and environmental sustainability. He includes Australian cities in his book, from understanding how the different designs of two Melbourne suburbs directly affect the amount of carbon dioxide released into the atmosphere, to Sydney's struggle as a 'Great Opportunities City' - a place that has everything going for it but chronically fails to become what it could be. Brugmann offers a new way of looking at cities and demonstrates that the most effective way to prevent all-out disaster in the new millennium is to concentrate efforts at the level of the city.