Half of US household carbon footprint comes from suburban sprawl

Suburban sprawl accounts for half of the total U.S. household carbon footprint, scientists say, canceling out urban attempts to reduce greenhouse gas emissions. While many U.S. cities are taking steps to grow urban centers to reduce emissions, population-dense suburbs contribute significantly higher carbon footprints on average than lower density suburbs and city centers, they said. Researchers Christopher Jones and Daniel M. Kammen, writing in the journal Environmental Science & Technology, note U.S. households, though they only comprise 4.3 percent of the global population, are responsible for about 20 percent of annual worldwide greenhouse gas emissions. Jones and Kammen created an analytic model using national survey data to estimate average household carbon footprints for over 30,000 zip codes and 10,000 cities and towns in all 50 U.S. states. Such data are vital, as many governors and mayors across the United States have pledged to reduce their states' and cities' emissions, they said -- and information on the size and composition of household carbon footprints is needed to inform policies to make these reductions happen. "An entirely new approach of highly tailored, community-scale carbon management is urgently needed," they concluded in their study, which was partially funded by the California Air Resources Board and the National Science Foundation.