Imagine a world where flying from Rome to New York does not contribute to climate change, where airplanes cross the skies without leaving a carbon trace. An unattainable utopia or an imminent reality?
The aviation sector, responsible for approximately 2–3% of global CO2 emissions (cdp.it), is under pressure to find sustainable solutions. New technologies promise zero-emission flights, but how close are we to reaching that goal?
The Challenges of Sustainable Aviation
The transition to zero-emission aviation is fraught with technological, economic, and infrastructural challenges. On the one hand, the aviation industry has made great strides in reducing fuel consumption and optimizing flight routes; on the other, it remains largely dependent on fossil fuels.
One of the main obstacles is economic feasibility: zero-emission technologies such as electric or hydrogen-powered engines require massive investments in research and development. Additionally, many airlines are already burdened by debt accumulated during the pandemic, making it difficult to allocate funds to long-term projects without immediate returns. Logistics and airport infrastructure also pose a critical issue. Airports would need to be converted to support electric aircraft charging or liquid hydrogen refueling—operations that require advanced facilities and new safety regulations. Currently, only a few experimental facilities have been adapted to these new standards.
A key factor: consumer perception
Although interest in sustainable travel is growing, many passengers are reluctant to accept price increases to cover the costs of the transition. Until sustainable flights become cost-competitive with traditional ones, their adoption will remain limited. Government regulations play a crucial role in developing these new practices, especially because an economically viable alternative to traditional fuels is not yet available. While some European countries have already imposed emission reduction targets for airlines, other regions have yet to implement clear regulations, creating disparities across the industry and in airfare pricing.
Sustainable Fuels: An Immediate Solution?
Sustainable Aviation Fuels (SAFs) represent one of the most viable short-term solutions for reducing emissions without completely redesigning aircraft.
SAFs can be produced from renewable sources such as used cooking oils, agricultural waste, and algae, reducing CO2 emissions by up to 80% compared to conventional fossil fuels. However, their widespread adoption still faces several obstacles, including high costs, limited production, and difficulties in integrating with existing infrastructure. One of the main issues is cost. Currently, SAFs cost up to three times more than traditional kerosene, a factor that limits their market competitiveness. However, research is exploring methods to reduce production costs, such as refining organic waste and cultivating genetically modified algae to increase yield. Investments in new bioconversion technologies could significantly reduce the cost of these fuels in the coming years.
Limited production
In 2024, global SAF production was around one million tonnes—well below the aviation sector’s needs. To increase this quantity, new refining plants and government incentives are needed to facilitate large-scale production. Some countries are already investing in building bioenergy refineries, with the aim of making SAFs more accessible.
There is also the issue of compatibility with existing aircraft. Although SAFs can be blended with traditional kerosene, only a few aircraft are currently capable of running 100% on sustainable fuels. To overcome this barrier, Boeing and Airbus are developing new engines optimized for SAFs, while airlines are testing gradual increases in the percentage of biofuel used on commercial flights.
Despite these challenges, some governments and airlines are promoting the use of SAFs through research programs, tax incentives, and regulatory mandates. However, without a drastic increase in production and a reduction in costs, their impact will remain marginal in the short term. The key to SAFs’ success lies in innovation in production and institutional support to accelerate their widespread adoption.
The Frontiers of Sustainable Aviation Research
The aviation industry is exploring a wide range of technologies to transform air transport and make it truly sustainable.
Alongside electrification and hydrogen, surprising innovations are emerging that could revolutionize the sector. Plasma propulsion, currently being studied in the aerospace field, could generate thrust without traditional fuels by using electric fields to ionize air and produce propulsive energy. This technology, still in the experimental phase, could have revolutionary applications in the coming decades.
At the same time, the concept of blended wing body aircraft is gaining attention. These planes, instead of having a traditional separation between fuselage and wings, integrate the structure into a single aerodynamic body, reducing air resistance and improving fuel efficiency. Projects like TU Delft’s Flying-V demonstrate how this innovation could reduce energy consumption by up to 20% compared to conventional aircraft.
Another promising direction is the development of solar-powered aircraft, with ultra-efficient photovoltaic panels capable of storing energy for night flights. Although currently limited to small experimental drones, advances in solar cells and battery technology could one day allow long-distance flights powered entirely by solar energy.
Finally, Artificial Intelligence is revolutionizing air traffic management and flight route optimization, significantly reducing fuel consumption without the need for direct intervention on engines or fuels. The use of advanced weather forecasting and flight management software could already lead, in the coming years, to a global CO2 emissions reduction of up to 10%.
