Carbon footprint of travel per kilometer in the UK 2023, by transportation mode

In 2023, passengers travelling on a domestic flight had the largest carbon footprint of transportation modes in the UK, at 270 grams of carbon dioxide equivalent per kilometer (g CO₂e per km). By comparison, the carbon footprint of passengers travelling by train was just 40 g CO₂e per km.

Which cars have the largest carbon footprint?

After flights, cars typically had the highest carbon footprints per kilometer in the UK. The average petrol car produced the equivalent of 164 grams of CO₂e per km in 2023, while diesel cars averaged roughly 170 grams of CO₂e per km. Both vehicle types had higher emissions per kilometer than the average battery electric vehicle (BEV). In terms of market segments, luxury cars had the highest average carbon footprint of all car types. Passenger cars are the largest source of UK transportation emissions by far.

Transportation emissions in the UK

There has been little change in UK transportation GHG emissions over the past three decades, except for a dramatic slump in 2020 due the outbreak of COVID-19. Emissions rebounded in 2021 to roughly 110 MtCO₂e. Although this was below pre-pandemic levels, transportation was still the largest source of emissions in the UK.