CO2 emissions of new UK passenger car registrations – Assessing technical and market evolutions in the past decade (2010-2019)

This paper investigates the evolution of carbon dioxide emissions of new passenger car registrations in the United Kingdom during the period 2010-2019, as well as market trends for vehicle characteristics that influence these emissions. A disaggregation of the CO2 emissions series is performed in order to establish the distinct effects of powertrain technological changes and market-related fluctuations. The analysis shows that the overall variation of -11.44% over the decade was primarily due to the technical improvements of fuel-powered vehicles (-13.52%) and a shift in fuel type (-3.33%), undermined by a rise of the average vehicle mass leading to an increase of the emissions by 5.85%. The impact of engine size is negligible (0.08% uplift in emissions), following a reversal of the decreasing trend during the last few years. While the 2015 CO2 target from regulation was achieved two years ahead, a comparison with the requirements from past and future targets shows that the improvement rate observed during the past decade remains much lower than expected. Therefore, it appears that the current trend is far from adequate to achieve any of the upcoming regulatory changes, and that a substantial acceleration is required, through considerably larger gains in pure technical improvements in the coming years combined with a consequential shift towards electrified vehicles