Synergistic decarbonization: the role of grid cleanliness and new energy vehicles adoption in China’s transport-energy transition

As one of the major sources of global carbon emissions, the transportation sector faces significant challenges in its decarbonization process. Against this backdrop, China—with the world’s largest new energy vehicle (NEV) market—serves as an important case for systematically evaluating the carbon reduction mechanisms and potential of vehicle electrification. By integrating life-cycle assessment (LCA) with provincial panel econometric models, this study examines the dual-path carbon mitigation mechanisms of NEVs in China during the 2016–2022 period. Results indicate that a 1 percentage point increase in NEV market share reduces annual carbon emissions by 0.358%, driven by a short-term substitution effect—replacing internal combustion engine vehicles—and a long-term technological effect encompassing advancements in manufacturing efficiency and power grid decarbonization. LCA further confirms that battery electric vehicles exhibit the lowest carbon footprint, achieving an average reduction of approximately 16.4 metric tons of CO2 equivalent in life-cycle emissions compared to conventional vehicles. The study also reveals notable regional heterogeneity: higher levels of economic development and logistics intensity amplify NEV-related emission reductions, while the degree of electricity supply decarbonization determines their long-term effectiveness. These findings establish a multi-dimensional framework for transportation and energy policy, emphasizing that vehicle electrification must align with clean energy transition to achieve carbon neutrality.