Prospective life cycle assessment of future Swedish hydrogen-powered aviation pathways

• A prospective life cycle assessment on future air travel pathways in Sweden. • Hydrogen pathways show higher toxicity, land and water use impacts than fossil fuel. • Hotspots are resources in energy infrastructure and energy demand in aviation systems. • Environmental performance of air travel is dependent on out-of-sector developments. • There is a limit to technology and energy efficiency improvement. Hydrogen-powered aviation is promoted as a low-carbon alternative for future long-distance air travel, but its broader environmental impacts remain unclear. This study evaluates the potential environmental impacts of six future air travel pathways in Sweden, including e-kerosene, liquid hydrogen, and fossil kerosene, using prospective life cycle assessment. Results show that hydrogen-powered aviation has lower global warming potential than fossil kerosene but higher impacts on other environmental issues, such as toxicity and land use. Key hotspots include resources in energy infrastructure and energy use in fuel production and airport operations, however, resource substitutions and energy efficiency improvements have limits. This study highlights the potential environmental benefits and tradeoffs of hydrogen-powered aviation, and also the dependency of aviation on other sectors. Further research should integrate technological innovations in long-distance air travel pathways with scenarios that account for demand-side measures, as well as regulatory, political, and economic barriers.