1 of every 2 humans live in cities and this will soon be 2 of every 3. The city defines the quality of life of its inhabitants more than any other factor at a mass scale, and on the individual. The impact of a city is huge. From climate change to economic vitality to our very well-being and sense of connectedness. How a city is designed matters. Peter Calthorpe is already at work planning the cities of the future and advocating for community design that’s focused on human interaction. He shares seven universal principles for solving sprawl and building smarter, more sustainable cities.