Global transport emissions 1850–2020: Historical drivers and lessons for transport decarbonization

This study analyzes global transport CO₂ emissions from 1850 to 2020 using the LMDI method, offering, for the first time, a decomposition over such a long timespan and global scope. Emissions are split into technological and demand-related drivers using a new dataset. Transport efficiency is divided into final-to-useful efficiency and useful energy intensity, a novel distinction. Key findings include: (1) efficiency improvements avoided 9067 Gt CO₂ by 2019, with peak impacts in 1950–1973 (-1.62 %/yr) and 2008–2020 (-3.63 %/yr), respectively; (2) these gains were insufficient to counter rising demand, which led to 8252 Gt CO₂ in cumulative emissions; (3) demand growth driven by GDP per capita, service intensity, and population accounted for 16 683 Gt CO₂ in 2019, with service intensity dominating in 1850–1913 (+3.97 %/yr) and GDP and population drivers peaking in 1950–1973 (+2.57 % and +1.83 %/yr); (4) keeping emissions at 2020 levels through 2029 would require electricity to supply 52 % of transport energy.