摘要:The world's metropolitan carbon footprints have distinct geographies that are not well understood or recognized in debates about climate change, partly because data on greenhouse gas emissions is so inadequate. This article describes the results of the most comprehensive assessment of carbon footprints for major American metropolitan areas available to date, focusing on residential and transportation carbon emissions for the largest 100 metropolitan areas in the United States. These findings are put into the context of efforts across the country and the globe to characterize carbon impacts and policy linkages.