Emission location shape atmospheric and climate effects of alternative fuels in domestic aviation

Aviation emissions significantly contribute to global warming, necessitating reductions to align with the 1.5°C target. Beyond carbon dioxide emissions from fossil jet fuel combustion, non-CO2 emissions play a crucial role, exhibiting diverse impacts on atmospheric chemistry and radiative forcing based on geographic location, altitude, and time. To enhance comprehension of aviation emissions and potential alternative fuels, we introduce the AviTeam model—a data-driven, high-resolution model utilizing ADS-B data to quantify emissions of various species, including NOx, CO, BC, SO2, H2O, and hydrocarbons, alongside CO2.  Integrating AviTeam's emission inventory with the OsloCTM3 chemical transport model allows us to assess the regional impact of aviation emissions. We explore the atmospheric chemistry effects of transitioning to liquid hydrogen and synthetic fuels as alternatives to fossil jet fuel. Additionally, a contrail formation potential analysis reveals that hydrogen exhibits a higher non-persistent contrail-forming potential than kerosene due to its elevated water vapor emissions. Our findings suggest that in high-latitude regions, adopting alternative aviation fuels may yield different mitigation effects with fewer trade-offs between non-CO2 and CO2 impacts than global averages suggest. However, the mitigation potential of alternative aviation fuels from a life cycle perspective is constrained to 44–56% reduction in GWP100, attributed to short-lived climate forcings and additional fuel demand for liquid hydrogen. Notably, the mitigation potential is less pronounced on shorter flights. Our results underscore the importance of integrating models like AviTeam with chemical transport models and life cycle perspectives to emphasize the significance of accounting for local atmospheric conditions and better understand variability in aviation emissions studies.