Years ago I was at a talk where someone pointed out that the entire downtown area of Providence, RI, where I lived at the time, could easily fit within the footprint of the parking lot of suburban malls. I don't want to push environmental arguments for urbanism too far, but I do remember when cities were seen as "not green" because they were urban hellhole concrete jungles lacking trees and grass. I'm glad that in recent years there's been an increased recognition that whatever one personally thinks of cities (live where you want!), from an environmental perspective they're probably an improvement. People gotta live somewhere, but they don't necessarily have to take up that much space.