No less than America’s most famous architect, Frank Lloyd Wright, once imagined a mile-high city. According to Al, Wright argued that “Manhattan could be razed ‘to one large green’ with only a few mile-high buildings. You could ‘sweep New York into the Hudson and build two of them in Central Park and that would be the city.’ Ten buildings could ‘rehouse almost the [island’s] entire office population.’”

This vision is, obviously, extreme. Other than some very weird corners of the internet, no one is suggesting that all human beings should be packed into supertalls. But Wright’s logic is worth examining, because he thought of the mile-high city as a feat not only of technology and design, but of conservation. And this brings me to the environmental case against supertalls. Instead of viewing large, concrete-intensive structures as oppositional to emissions goals, we should see them as complementary. Without skyscrapers, many of those offices and residences would still be built; they’d just take up more space.

Al makes this point succinctly in comparing Manhattan with Phoenix, Arizona: “Manhattan has more skyscrapers, hence is more dependent on energy-intensive structures. Nevertheless, in the sprawling city of Phoenix, people need cars and miles and miles of energy and water lines. At the same time, dense urban development helps preserve land for environmental or agricultural benefits. Manhattan has more than twenty times the population density of Phoenix. If Manhattanites were spread out as much as people in Phoenix, they would require twenty times more land.”