title: Does size matter? Scaling of CO2 emissions and US urban areas.
abstract: Urban areas consume more than 66% of the world's energy and generate more than 70% of global greenhouse gas emissions. With the world's population expected to reach 10 billion by 2100, nearly 90% of whom will live in urban areas, a critical question for planetary sustainability is how the size of cities affects energy use and carbon dioxide (CO2) emissions. Are larger cities more energy and emissions efficient than smaller ones? Do larger cities exhibit gains from economies of scale with regard to emissions? Here we examine the relationship between city size and CO2 emissions for U.S. metropolitan areas using a production accounting allocation of emissions. We find that for the time period of 1999-2008, CO2 emissions scale proportionally with urban population size. Contrary to theoretical expectations, larger cities are not more emissions efficient than smaller ones.
authors.affiliation: Department of Economics, Boise State University, Boise, Idaho, USA. michailfragkias@boisestate.edu
authors.forename: Michail
authors.initials: M
authors.lastname: Fragkias
authors.forename: José
authors.initials: J
authors.lastname: Lobo
authors.forename: Deborah
authors.initials: D
authors.lastname: Strumsky
authors.forename: Karen C
authors.initials: KC
authors.lastname: Seto
mesh_terms: D001272:Atmosphere / Q000737:chemistry; D002245:Carbon Dioxide / Q000032:analysis*; D002947:Cities / Q000706:statistics & numerical data*; D017752:Greenhouse Effect; D011156:Population Density; D014481:United States
chemical_list: D002245:Carbon Dioxide