Grist: It is a given among environmentalists and planning professionals that higher density reduces carbon emissions from transportation. Denser communities allow for more walking, biking, and transit use. And even when you drive, a shorter trip burns less fuel. So we can assume that vehicle emissions per capita will drop as a city grows denser, but weve known very little about exactly how much - until now.
According to a new study by Boston University environmental scientists, published in the Proceedings...