Urban form, air pollution, and CO₂ emissions in large U.S. metropolitan areas

In this article we explore the relationships between urban form and air pollution among 86 U.S. metropolitan areas. Urban form was quantified using preexisting sprawl indexes and spatial metrics applied to remotely sensed land cover data. Air pollution data included the nonpoint source emission of the ozone (O₃) precursors nitrogen oxides (NOx) and volatile organic compounds (VOCs), the concentration of O₃, the concentration and nonpoint source emission of fine particulate matter (PM2.5), and the emission of carbon dioxide (CO₂) from on-road sources. Metropolitan areas that exhibited higher levels of urban sprawl, or sprawl-like urban morphologies, generally exhibited higher concentrations and emissions of air pollution and CO₂ when controlling for population, land area, and climate.