Extending urban stocks and flows analysis to urban greenhouse gas emission accounting: A case of Odense, Denmark

Cities generate greenhouse gas (GHG) emissions both in the construction phase of their built environment stocks and durable goods and in their operation phase with energy and material flows. Existing urban GHG accounting methods, however, focus largely on emissions related to energy and material flows and have rarely considered the role of urban stocks. In this article, we have extended urban stocks and flows analysis to urban GHG accounting, using bottom-up and high-resolution urban stocks and flows information for a case of Odense, Denmark. We introduced a complementary indicator of carbon replacement value (CRV) to account for emissions embodied in the urban stocks and determined the CRV of Odense as 10.7 megatons of CO2 equivalent (or 53 metric tons per capita) in 2017, equivalent to 13 years of Odense's operational emissions. The comparison between CRV and operational emissions across urban activities facilitates a better understanding of the carbon profile of the city and opportunities for decarbonization. Such urban metabolic based GHG accounting and inclusion of stocks can help to estimate the amount of GHG emissions to be expected from the further urbanization in developing countries as their urban stocks continue to increase and inform their potentials for leapfrogging in emission reduction.