Carbon footprinting is a method to generate data about the GHG emissions of transport services. Availability of such information is regarded as one means to limit the emissions and improve the efficiency of transport. However, the existence of many standards, initiatives and calculation tools makes different carbon footprints mutually incomparable, thus hampering the potential of this measure.
To harmonize carbon footprinting and to allow benchmarking of transport services, four policy options were identified. The options address increased reporting on the one hand and the level of harmonization of calculation methods on the other. The study concludes that a methodology representing real-world fuel consumption data scores highest on improving the accuracy and reliability of the carbon footprints, and consequently has the best cost/benefit ratio for GHG reduction. This option, however, is perceived as realistic only for voluntary reporting.