Modeling energy consumption and CO2 emissions at the urban scale: Methodological challenges and insights from the United States

Local policy makers could benefit from a national, high-resolution inventory of energy consumption and related carbon dioxide (CO2) emissions based on the Vulcan data product, which plots emissions on a 100 km2 grid. We evaluate the ability of Vulcan to measure energy consumption in urban areas, a scale of analysis required to support goals established as part of local energy, climate or sustainability initiatives. We highlight the methodological challenges of this type of analytical exercise and review alternative approaches. We find that between 37% and 86% of direct fuel consumption in buildings and industry and between 37% and 77% of on-road gasoline and diesel consumption occurs in urban areas, depending on how these areas are defined. We suggest that a county-based definition of urban is preferable to other common definitions since counties are the smallest political unit for which energy data are collected. Urban counties, account for 37% of direct energy consumption, or 50% if mixed urban counties are included. A county-based definition can also improve estimates of per-capita consumption.