Commuting carbon dioxide (CO2) emissions: a study of ten Italian metropolitan cities

Carbon emissions related to daily trips to work/study place have hitherto played an ancillary role in transport problems. This study investigates CO2emissions related to commuting in/from/to ten largest Italian metropolitan cities. Not only the flows in the commuting zones defined by the OECD and the European Commission, but all the inbound and outbound flows have been considered. Commuting flows from census data are associated to province-specific car emission factors. Open data are handled in order to build a thorough database. The researchers provide a straightforward methodology to account commuting carbon footprint. The results show that commuting in/from/to the cities considered accounts nearly the 4 percent of total transport CO2emissions in Italy: the two-thirds come from the 31 percent of the commuters, which corresponds to transboundary journey (from/to). The main driver is a significant use of private means of transport with a low occupancy rate. The importance of cities in moving towards sustainable commuting, both for the shorter distance travelled (compactness) and the wider availability of less-emitting modes of transport (walkability, biking, public means) is highlighted.