How is nature critical to a twenty-first century urban ethic?

Question Background:
Today, for the first time in history, most people are city-dwellers. How do we nurture urban places that foster meaningful connections among humans and nature? Chicago is one city searching for creative answers. Inspired by two of our partners in Chicago, the Forest Preserves of Cook County and Chicago Wilderness, the Center asks a national audience: How is nature critical to a twenty-first century urban ethic? What do you think?
Image credit: Robert Elves