Some years back, I took a bus ride to a climate rally in New York City with a bunch of other activists. My seatmate was 12 years old, a smart kid from the suburbs who had never been to New York. As we approached Manhattan on the Cross Bronx Expressway, he looked out at a block of concrete apartment buildings and said something like: This is what happens when you don’t care about the environment. Actually, I replied, this is green living: People live close together; they can walk or take public transit; they live in apartments, share walls and heat and are relatively energy efficient; their carbon footprint is far lower than a family in a “green”, leafy single-family suburban house.