Quantifying delayed climate mitigation benefits in electric and hydrogen fuel cell vehicle deployment for sustainable mobility

In the fight against climate change, transitioning to green transport is imperative. Our study evaluates the Greenhouse Gas Emission Breakeven Time (GBET) for Electric Vehicles (EVs) and Hydrogen Fuel Cell Vehicles (HFCVs) in China, the largest auto market globally. Emissions vary significantly across Chinese provinces due to differences in grid carbon intensity, hydrogen production methods, and vehicle usage. EVs show more than a 50 % difference in Well-to-Wheel (WTW) emissions regionally, which is also true for HFCVs, although they exhibit less interprovincial variability, suggesting a steadier reduction trend. These findings stress the need for regional considerations in Life Cycle Assessment (LCA) and introduce the concept of “climate debt” to evaluate the delayed benefits of emission reductions. HFCVs, benefiting from cleaner hydrogen production advancements, can repay their climate debt about 60 % quicker than EVs, presenting a caveat: the risk of short-term emission spikes if the initial greenhouse gas surplus isn't efficiently compensated. We found that the GBET for EV-Cars is about 3.39 years and for EV-SUVs (Sports Utility Vehicle), 4.23 years. Comparatively, HFCV-Cars and HFCV-SUVs have shorter GBETs of roughly 1.39 and 1.43 years, respectively, indicating faster environmental paybacks. Conclusively, our study endorses regional assessment frameworks and highlights HFCVs' role in China's path to a low-carbon future. It is essential for sustainable mobility stakeholders to adapt vehicle technology adoption and related policies to local energy contexts to meet climate goals. Our research provides crucial insights into how green vehicles can achieve emission targets, advocating for a localized approach in sustainable transportation strategies. © 2024 Institution of Chemical Engineers. Published by Elsevier Ltd.