Environmental consequences of Japan's ban on sale of new fossil fuel-powered passenger vehicles from 2035

Despite the recent increase in vehicle electrification, the transport sector remains a major contributor to the rise in global CO₂ emissions. Using dynamic product lifecycle (LC) models, we analyzed the relationship between LC-CO₂ emissions and the proportion of electric vehicle (EV) sales in Japan, where the introduction of EVs could increase LC-CO₂ emissions. We considered the contributions of vehicle fuel efficiency and vehicle lifetime to LC-CO₂ emissions under three scenarios—changes in sales, improvements in fuel efficiency, and changes in vehicle lifetimes. Our findings show that promoting EVs and decarbonization in the electricity sector will decrease CO₂ emissions during the driving phase. However, even if the energy mix follows the net zero emission target, emissions from the vehicle manufacturing phase will largely remain, and the manufacturing emissions from electric will account for over 50% of the total emissions in 2050, even when the vehicle lifetime is extended by 5 years. Although the decarbonization of the power sector and vehicle electrification are important steps toward reducing LC-CO₂ emissions, they are insufficient. Thus, to reduce LC-CO₂ emissions, including those from the manufacturing phase, the Japanese government needs to focus on decarbonizing the supply chain and extending vehicle lifetime, especially that of EVs, as well as reducing driving phase emissions.