California has decided it needs to densify all of its cities to meet its greenhouse-gas emissions targets. The state’s goal is to reduce emissions by 40 percent from 1990 levels by 2030. Since the state’s leaders don’t believe fuel efficiencies and other energy economies will be sufficient, they want to reduce per capita driving by 12 percent.
California already has the densest urban areas in the United States. The 2010 census found that, among urban areas (areas above 50,000 in population), Los Angeles is first at 7,000 people per square mile. San Francisco-Oakland is second at 6,266, San Jose is 5,820, while New York is a distant fourth at 5,320. The average density of all California urban areas was 4,577, more than any other state except New York, whose average density was just slightly above that at 4,580. California’s average was nearly twice the rest of the nation whose urban area densities averaged 2,347 per square mile. Remember, these are urban areas, not cities.
The idea that increased densities will reduce California’s greenhouse gas emissions is an urban-planning fantasy that the legislature has imposed on the state’s residents. The state’s population is expected to grow by 4.5 million by 2030, and if every single one of those people settles in an urban area, the densities will increase to around 5,200 people per square mile. While people drive a lot less in New York City (not the urban area), whose density is 25,000 people per square mile, increasing densities to 5,200 people per square mile isn’t going to much change travel habits. As University of California Irvine economist David Brownstone says, the effect of density on driving is “too small to be useful” in reducing greenhouse gas emissions.
Density has a major effect on another variable: housing prices. A paper by Issi Romem of Buildzoom.com points out, no city has been able to contain itself within urban limits and, within those limits, built enough dense housing to keep housing affordable. Dense housing is simply more expensive than low-density housing: the land is more expensive, construction is more expensive, and labor in more expensive housing markets is more expensive. Basically, he concludes, regions have a choice between becoming more expensive or more expansive.
California has clearly chosen the more-expensive course. This not only harms low-income people, it makes it more difficult to get denser because people don’t want to move to a state they can’t afford to live in. So I expect that California is going to miss any targets it sets for reducing per capita driving, though it might meet its emissions targets simply by driving away of lot of potential emitters.