text: 70 percent of Vauban's families do not own cars, and the 57 percent sold a car to move there. Some say they feel happier now than before when they had a car. Automobiles are the linchpin of suburbs, where middle-class families from Chicago to Shanghai tend to make their homes. Greenhouse gas emissions are reduced drastically. Passenger cars are responsible for 12 percent of greenhouse gas emissions in Europe, and up to 50 percent in some car-intensive areas in the U.S.