Currently, over half of the world’s population and the vast majority of the US population live in urban areas. It is estimated that the majority of fossil fuel carbon dioxide (FFCO2) and a significant proportion of anthropogenic methane (CH4) are generated in urban areas worldwide. However, errors when quantifying urban FFCO2 and urban CH4 emissions are high. As urban and metropolitan areas continue to grow in the US and around the world, urban greenhouse gas emissions must be quantified more accurately in order to assess the human influence on the carbon cycle and climate.
AC4 supports research such as quantifying urban carbon emissions by source, modeling urban emissions, determining the effects of urban activities on ecosystem flux, and developing tools and policies to manage emissions. Starting with FY14 program announcement, AC4 focuses on quantifying emissions of greenhouse gases, aerosols, and their precursors. AC4 is currently funding three projects that are specifically classified as urban emissions projects, as well as several other emissions projects that incorporate urban emissions research. Descriptions of these projects can be found in the Funded Projects section of the website.