Sustainable Cities

NEW YORK – To most people, big, densely-populated cities look like ecological nightmares, wastelands of concrete and garbage and diesel fumes and traffic jams. But, compared to other inhabited places, cities are models of environmental responsibility. By the most significant measures, the greenest community in the United States is New York City, the only American city that approaches environmental standards set elsewhere in the world.

The average New Yorker generates 7.1 metric tons of greenhouse gases annually; that is more than the average Swede, who generates 5.6 metric tons, but it is less than 30% of the US average of 24.5 metric tons. Residents of Manhattan, the most densely populated of the city’s five boroughs, generate even less.

The key to New York’s relative environmental benignity is its extreme compactness. Manhattan’s density is approximately 67,000 people per square mile, or more than 800 times that of the US as a whole and roughly 30 times that of Los Angeles. Moving people closer together reduces the distances between their daily destinations and limits their opportunities for reckless consumption, as well as forcing the majority to live in some of the most inherently energy-efficient residential structures in the world: apartment buildings.