A global environmental impact analysis of passenger vehicle energy and powertrain technologies

Passenger vehicle sustainability aligns with the 13th Sustainable Development Goal (Climate Action) of the United Nations. This study evaluates zero-emission vehicles (ZEVs) — fuel cell vehicles (FCVs) and battery electric vehicles (BEVs) — against conventional and alternative internal combustion engine vehicles (ICEVs) using gasoline, diesel, compressed natural gas (CNG), methanol, hydrogen variants (blue, gray, green), hybrids (HEVs), and plug-in hybrids (PHEVs). A well-to-wheel life-cycle assessment (LCA) quantifies global warming, acidification, and eutrophication potentials, with sensitivity analysis across 15 vehicle-fuel systems. Focused on Saudi Arabia (2024–2030) and extended globally, the LCA identifies green hydrogen FCVs as optimal, reducing life-cycle emissions by 77.8%, followed by green hydrogen ICEVs, blue hydrogen FCVs, and gray hydrogen FCVs. Blue hydrogen ICEVs, BEVs, and CNG HEVs achieve 27.9%–33.6% reductions, while other alternatives underperform. Fossil-based HEVs and ICEVs demonstrate superior performance in minimizing acidification and eutrophication impacts. Projected 2030 scenarios (50% renewable energy penetration) elevate BEVs’ carbon reduction potential to 60%. Hydrogen vehicles serve as transitional solutions in high-carbon grid regions, whereas BEVs dominate in low-carbon grids. Enhancing grid decarbonization remains critical to maximizing ZEVs’ efficacy.