Alisha Newton | Vanderbilt Orbis

Macau (Flickr Creative Commons)
Macau (Flickr Creative Commons)

Macau, China is one of the world’s densest cities, with 44,183 people per square mile. Nearly half of the families in Macau live in dwellings that have an average of 180 square feet per person, which is about the size of a large bedroom. Because of their space-efficient lifestyles and their use of public transit, each resident of Macau citizen is responsible for roughly 3 metric tons of carbon emissions per year — one sixth of the carbon footprint of the average American.

True, it’s not fair to compare the city of Macau to the entire expanse of the United States. But even our densest city, New York, is half as dense as Macau, with 27,000 people per square mile, and we have dozens of other cities that are low-density and high-carbon. Take Nashville, Tennessee, one of the highest carbon-producing cities in the U.S.

Of course, Nashville is part of the southeastern United States, which suffers from the same set of carbon challenges, like historical dependency on coal for electricity. But Nashville looks bad even compared to other cities in the South. For example, Charlotte, North Carolina, is a peer city to Nashville based on the two cities’ population sizes and growth rates, but Charlotte is still much more energy-efficient.

The key difference lies in density: Music City has 1319 people per square mile, compared to Charlotte’s 2663 people per square mile. Fewer people per area means sprawl, and sprawl makes the city necessarily car-dependent. When people have to drive from home to workplace, the city consumes much more fuel. Read more