kahn09-large7.jpg

Not a carbon copy of the U.S. — Asia’s urban approach to reduced energy use

China, a manufacturing powerhouse, is already the world’s biggest carbon emitter, but ordinary Chinese remain remarkably parsimonious in their energy use. Matthew Kahn, Rui Weng, Siqi Zeng and I, in a study published in 2010, estimated carbon emissions for urban households in China, measuring only household emissions and personal transportation. In our sample, the average Chinese household emitted less than 2.2 tons of carbon dioxide a year, which is less than 1/17th of the levels that Kahn and I found in an earlier study of U.S. cities. Even the greenest U.S. metro areas, such as San Jose and San Francisco, emitted almost 12 times as much as carbon as the Chinese metropolitan areas.

Kahn and I, in our previous study of the United States, compared emissions inside and outside major cities, and found significantly lower emissions in urban cores, even holding income and family size constant. This was because dense urban areas have smaller homes and require less driving. Households in areas with more than 10,000 people per square mile use an average of 687 gallons of gasoline a year; households in areas with fewer than 1,000 people per square mile use 1,164 gallons of gas a year. The average detached home consumes 88% more electricity than the average apartment in a large building.

To read the full article by Edward Glaeser in the LA Times Opinion section click here.