Driving down road transport CO2 emissions in Scotland

This study develops an empirical model of regional road transport CO2 emissions for Scotland to investigate the relative importance of demand-led and supply-led factors, particularly those relating to fuel efficiency and the decarbonization of the vehicle fleet through the switch to alternative fuels. The analyses suggest that although significant, the positive impact of fleet decarbonization in the reduction of road transport CO2 emissions is very small given the current levels of adoption of cleaner fuels. Instead, efforts to improve fuel efficiency are likely to be more effective at reducing emissions than fleet decarbonization. The main sources of regional variation in road transport CO2 emissions relate to demand-led factors, in particular differences in urbanization, vehicle ownership, income levels, and the presence of freight-related traffic.