As efforts to tax or price carbon falter, countering climate change will rely on encouraging low-carbon urbanism, according to Kahn.
"Up until this point, there has not been the political will either at Copenhagen in late 2009 or in the U.S Senate in 2010 to enact such regulation. In the absence of such explicit anti-carbon incentives, we need to encourage the growth of those cities that have relatively small carbon footprints. In the United States, cities such as San Francisco have a smaller carbon footprint than cities such as Houston. In San Francisco, residents live in smaller housing units at higher population density. They are more likely to use public transit and due to the temperate climate, they consume less electricity. Electricity generated in California creates less greenhouse gas emissions than other cities because the power is generated using natural gas rather than coal. In China, northern cities in colder climates that require more winter warmth use ample amounts of coal and this increases such city's carbon footprint relative to more southern cities."