We have political and economic systems that have successfully delivered an unequal, resource-intensive and environmentally-destructive material world organized into the urban form that is now facing a major crisis. Cities are the spatial expressions of the crisis of our material world, and the spatial concentrations of potential that need to be recognized and unleashed. Once the resource requirements of future urbanization and re-urbanization are calculated, the next step requires a realistic assessment of how we can dematerialize this urban future using a given set of technologies.