Carbon footprint of travel per kilometer in the UK 2024, by transportation mode

In 2024, passengers travelling on a domestic flight had the largest carbon footprint of transportation modes in the UK, at 273 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 165 grams of CO₂e per km in 2024, 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 had been little change in UK transportation GHG emissions since 1990, until a dramatic slump in 2020 due the outbreak of COVID-19. While emissions rebounded in the following two years, they are projected to have fallen again in 2023 to around 112 MtCO₂e. Although this figure is well below pre-pandemic levels, transportation is still the largest source of emissions in the UK.