By Edward Glaeser, MCT
If per capita carbon emissions in China and India rose to car-happy U.S. levels, global emissions would increase by 127 percent, according to the International Energy Agency.
If their emissions stopped at the levels found in hyper-dense Hong Kong, world emissions would go up less than 24 percent. As the Asian economies prosper, the United States should hope that they embrace the skyscraper more than the car, and we should reform our own policies that subsidize sprawl. 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 one-seventeenth 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. Our American households typically used more than 1,000 gallons of gasoline a year driving; the Chinese used about one-hundredth as much gasoline. In many American cities, carbon emissions from household electricity use can top 10 tons annually, but in China, the norm was slightly more than 1 ton per year. Poor countries heat before they cool, and China heats with particularly dirty energy sources, but even there, we found that the coldest Chinese cities were emitting about as much carbon in their home heating as Los Angeles, and far less than in the parts of America with real winters. The low carbon figures among Chinese households today mean that there is frighteningly large room for growth in Chinese energy use. The Chinese bought more than 18 million cars last year alone. India’s hot climate suggests that its household emissions may eventually be even higher, once a billion air conditioners come into operation. Massive Asian energy use raises fears of climate change, but even die-hard eco-skeptics should be anxious that soaring global energy demand will push up fuel costs. But no one should hope that China, India and Asian nations just stay poor. Fortunately, the same cities that are providing Asia with a path from poverty to prosperity also provide an urban approach to reduced energy use.