The Carbon City Index (CCI): A Consumption Based, Regional Input-Output Analysis of Carbon Emissions

This paper presents a consumption-based Carbon City Index for CO2 emissions in a city. The index is derived from regional consumption and not from regional production. It includes imports and exports of emissions, factual emission developments, green investments as well as low carbon city development policies and stakeholder engagement. The index is based on a multi-region input-output model used in most parts of the world for more than half a century. We demonstrate the index through comparative case studies of three Danish
regions: a rural region with a city center, the municipality of Sønderborg, a mid-sized city region, the municipality of Odense, and a metropolitan area, the municipality of Copenhagen. We demonstrate how city initiatives implemented to reduce emissions are translated into easy to access input-output parameters changes and how the index transparently assesses the emission impact of various possible municipal climate plans over time. As such, the index promotes the export of solutions from one region on another, as it enables policy makers to look elsewhere for best practices and test them on their own city before potential implementation. The index facilitates an easy to use and transparent comparison of factual and planned emission policies in different cities and can inform regional sustainability discussion and contribute to the dissemination of solutions.