A Dynamic Fleet-based Life Cycle Assessment Model for Evaluating Road Decarbonization Strategies

Abstract

The rapid growth of China’s light-duty passenger vehicle fleet poses a significant challenge to national decarbonization goals, as transportation emissions continue to rise alongside urbanization and economic development. This study develops a provincial-level Dynamic Fleet Emission Model (DyFEM) that integrates dynamic fleet projection, vehicle lightweighting, and fleet-based life cycle assessment to systematically evaluate the emission reduction potential of key decarbonization strategies—including vehicle electrification, lightweighting, and accelerated retirement policies. The analysis reveals that while large-scale adoption of electric vehicles can substantially reduce greenhouse gas emissions during the operation phase, the overall mitigation benefits are heavily dependent on the carbon intensity of the electricity grid and the emissions associated with vehicle and battery manufacturing. The study highlights that electrification alone is insufficient to achieve deep decarbonization targets, as production-phase emissions become increasingly prominent with higher EV penetration. Moreover, significant regional disparities exist due to differences in fleet size and grid mix, underscoring the need for region-specific strategies. Furthermore, the adoption of lightweight materials such as advanced high-strength steel and aluminium provides additional emission reductions, fuel savings, and eases demand for electricity and critical battery materials, especially if implemented early. The study emphasizes that lightweighting is a valuable complement to electrification and should be prioritized in the near term to maximize climate benefits, particularly while internal combustion engine vehicles remain prevalent in the fleet. Accelerated and targeted vehicle retirement strategies can further lower GHG and carbon monoxide emissions, but may increase other pollutants and production-related emissions if not carefully designed. The results highlight the necessity of an integrated, life-cycle-based policy approach that considers regional disparities, synchronizes vehicle renewal with grid decarbonization, and strengthens green supply chains and recycling infrastructure.

Date of Award	4 Sept 2025
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Xiaowei LUO (Supervisor)