Big Ideas for a Small Planet: Cities

A Portland real estate developer is the pioneering force behind turning a polluted brown field into a flourishing sustainable community. Years of research, engineering design, and money will be put to the test when an energy innovator submerges the first two underwater turbines in New York City's East river. Also, a band of guerrilla gardeners sneak around in the middle of the night to beautify plots of unused land with local plants and flowers for the community to enjoy.