Spatial Distribution of U . S . Household Carbon Footprints Reveals

8 ABSTRACT: Which municipalities and locations within the United States contribute the 9 most to household greenhouse gas emissions, and what is the effect of population density 10 and suburbanization on emissions? Using national household surveys, we developed 11 econometric models of demand for energy, transportation, food, goods, and services that 12 were used to derive average household carbon footprints (HCF) for U.S. zip codes, cities, 13 counties, and metropolitan areas. We find consistently lower HCF in urban core cities 14 (∼40 tCO2e) and higher carbon footprints in outlying suburbs (∼50 tCO2e), with a range 15 from ∼25 to >80 tCO2e in the 50 largest metropolitan areas. Population density exhibits a 16 weak but positive correlation with HCF until a density threshold is met, after which range, mean, and standard deviation of HCF 17 decline. While population density contributes to relatively low HCF in the central cities of large metropolitan areas, the more 18 extensive suburbanization in these regions contributes to an overall net increase in HCF compared to smaller metropolitan areas. 19 Suburbs alone account for ∼50% of total U.S. HCF. Differences in the size, composition, and location of household carbon 20 footprints suggest the need for tailoring of greenhouse gas (GHG) mitigation efforts to different populations.