How do we decarbonize one billion vehicles by 2050? Insights from a comparative life cycle assessment of electrifying light-duty vehicle fleets in the United States, China, and the United Kingdom

Electrifying light-duty vehicle fleets is essential to decarbonize road transport, however its efficacy relies on policies targeting country-specific challenges and opportunities. We model and compare fleet-level life cycle GHG emissions for different grid scenarios and battery electric vehicle deployment timelines respectively in the US, China, and the UK from 2020 to 2050, cumulatively involving over one billion vehicles. A customized index decomposition analysis is employed to quantify the contributions of key emissions drivers. Results reveal that electrification can be effective for decarbonizing all three fleets, reducing over 50% of annual life cycle emissions by 2050. Priorities and challenges, however, differ across countries: The US fleet, which emits the highest GHGs, generally comprises older, heavier, and less fuel-efficient vehicles, would benefit the most from electrification and fleet modernization. Grid decarbonization and managing car ownership growth are critical for China, as its rapidly growing fleet and manufacturing rely on currently carbon-intensive electricity. The UK needs to expand its electricity generation capacity while electrifying its fleet. We also underscore the need for a comprehensive strategy, including electrification, low GHG intensity fuels, and moderating vehicle ownerships. This study highlights the importance of cross-country life cycle thinking to inform effective decarbonization policy decisions. • Used vehicle fleet life cycle models to compare decarbonization in US, China and UK •Modified LMDI index decomposition to compare life cycle drivers of emission change •Fleet electrification matters for all but is more beneficial for the US •Grid decarbonization and limiting fleet growth are crucial for China •Fleet electrification is also critical in UK and benefits from its low-carbon grid