Abstract

As net-zero goals rapidly approach, attention has been devoted to “hard-to-abate” sectors from academics and industry alike. This research develops a novel model to estimate the land, water, energy, capital, and carbon footprints implied by commitment to sustainable aviation fuels (SAFs) and Liquid Hydrogen as aviation fuel sources to allow industry and governmental stakeholders to effectively consider these factors during decision-making. System feedbacks, including those required to recapture all carbon emitted through direct air carbon capture (DACC), are modelled. Biomass-based fuels are found to require more land and green water than their counterparts, while highly hydrogen-dependent fuels are more energy intensive. The inclusion of DACC is found to increase energy, blue water, and DACC capacity required by 25%. Higher carbon fuels are thus found to require more energy and blue water than literature predicts.

Eleven policy scenarios for UK aviation decarbonisation are evaluated for all international flights leaving the London Airport Cluster. Results indicate all scenarios require significant resources, trading off carbon for water, land, and energy use. Fuel pathway choice is found to be influential on the distribution and scale of environmental footprints; while sectoral growth and fuel efficiency improvement assumptions are found to influence their scale.