Decarbonizing Transportation: A critical examination of strategy effectiveness within sustainable energy capacity constraints

In this study, a consequential life cycle assessment to evaluate CO₂ emission reduction strategies in transportation is applied. The study focusses on fossil-fuel-driven vehicles, battery electric vehicles, and e-fuel-driven vehicles across various energy scenarios without constrictions to a specific region or period. A key discovery is the critical role of sustainable electricity availability in determining the effectiveness of these strategies. The study highlights the significance of strategically sequencing the electrification of energy subsectors, particularly under a constrained carbon budget. The findings indicate that, given the constraints on sustainable electricity supply in the short to medium term, battery electric vehicles do not achieve the expected reduction in CO₂ emissions, potentially rendering optimized fossil-fuel-driven vehicles with over 30% average efficiency a more effective interim solution. However, a tipping point exists where battery electric vehicles become a preferable solution in terms of CO₂ emissions, dependent on the share of sustainable electricity in the energy mix. By quantitatively analyzing the CO₂ reduction efficiency per unit of added sustainable electricity for different strategies, this study establishes a basis for informed, nuanced policy decisions.