An open thinking for a vision on sustainable green aviation

The main goal of this paper is to present a vision for the future of aviation. Developing such a vision is always a complex matter, but in times of environmental emergencies and unjustifiable wars it becomes even more difficult. One of the main reasons of this paper is to show that there is still room for advancing clean technology developments and to demonstrate that the aviation sector is ready for embarking on new challenge.

Green and environmentally sustainable aviation, in our opinion, can be achieved with continuous improvements along multiple parallel paths, ramp up of SAF (Sustainable Aviation Fuel) production, and of course, breakthrough technologies. The latter will require a significant amount of research, testing and probably mistakes need to be made before reaching the level of transportation efficiency and mission safety obtained with traditional propulsion, but these drawbacks should only encourage scientists, engineers, politicians and visionaries to strongly pursue the objectives of a new eco-aviation.

Aviation decarbonization requires a strategy change from near term improvements in aircraft fuel efficiency to long term (from neutral to zero carbon emissions) fuel switching. The successful introduction of long-term solutions requires transdisciplinary research into technological, operational and economy fields.

New technologies should probably be introduced into smaller aircraft segments first then migrate into the larger segments as the technologies mature. We should expect a first electric and hydrogen fuel cell commuter aircraft entry into service by the end of this decade, with hydrogen combustion-powered narrow bodies around 2040.

In 2019, aviation accounted for approximately 2.3% of global greenhouse gas emissions, with global commercial fleet CO₂ emissions totaling 0.918 Gigatonnes. Narrowbody and widebody aircraft produce over 95% of the industry's greenhouse gas emissions, therefore, while the introduction of new technologies on smaller aircraft will be important for the development of sustainable solutions, they will have minimal impact on the overall carbon footprint until they make their way onto larger platforms. However, carbon-free fueled (electric, hydrogen) aircraft will require significant infrastructure investments to develop the novel transportation network and the re-fueling procedures that will be required to support their use. Therefore, their success will require the coordinated combined efforts of the entire industry (airlines, airports, air navigation service providers, manufacturers) and significant government support.

This paper tries to summarize the most important aspects for a vision on sustainable green aviation and to indicate a possible roadmap for reaching this goal.