The future of aviation sustainability: Beyond sustainable aviation fuel

The future of aviation sustainability remains a contentious issue, as highlighted at last year’s World Aviation Festival in Amsterdam. Breeze Airways CEO David Neeleman made headlines when he publicly challenged the International Air Transport Association’s (IATA) stance on Sustainable Aviation Fuel (SAF). In a heated discussion with IATA CEO Willie Walsh, Neeleman questioned the feasibility, economic viability, and effectiveness of SAF as the primary solution to reducing carbon emissions in aviation.

While SAF has been widely embraced as a way to decarbonise air travel, Neeleman took a contrarian stance, arguing that the transition to SAF would significantly increase fuel costs, leading to higher ticket prices and reduced consumer demand. He further raised concerns about SAF’s reliance on biofuels, which could interfere with food supply chains.

“SAF interferes with the food supply. It doesn’t really solve the problem, and I think it’s just a complete waste of money,” he stated. Instead, Neeleman advocated for focusing on sustainability in other sectors, such as the development of greener fuels for diesel-powered vehicles.

His remarks ignited debate within the industry, reflecting a broader dilemma: while airlines are under pressure to decarbonise, there is no universal consensus on the best path forward.

The role of SAF in aviation’s decarbonisation strategy
SAF has emerged as one of the aviation sector’s primary solutions for reducing emissions. Produced from renewable sources such as waste oils, agricultural residues, and synthetic processes, SAF can cut lifecycle carbon emissions by up to 80% compared to traditional jet fuel. Despite this potential, adoption remains low, primarily due to high production costs and limited availability.

At the Airbus Summit 2025 held on March 24-25 at Toulouse, France, Guillaume Faury, CEO of Airbus, emphasised the challenges associated with SAF: “We need to make planes that burn less fuel and be more efficient, ensure better air traffic management, use fuels that put less carbon in the air. But SAF is significantly more expensive than traditional jet fuel. As a result, the economy and ecology are not aligned.”

Even proponents of SAF acknowledge that its price — three to five times higher than conventional jet fuel — poses a major hurdle to widespread adoption. Airbus’ Chief Sustainability Officer, Julie Kitcher, highlighted another issue: “The finance industry is moving away from the SAF sector, not towards it.”

To bridge the gap between supply and demand, Airbus is testing a “Book and Claim” system. This initiative allows airlines to purchase SAF credits even if they do not physically use the fuel, enabling more sustainable operations through emissions accounting mechanisms.

Elena Schmidt, Executive Director at the Roundtable on Sustainable Biomaterials (RSB), supported this model: “With the Book and Claim system in place, SAF is more affordable, more accessible, and more accountable. It will make the aviation sector more credible and sustainable.”

But how closely is the wider air cargo industry aligned with the vision of scaling SAF adoption and driving broader decarbonisation?

While 71% of companies report having a sustainability strategy, deeper indicators suggest a more cautious commitment in practice, according to TIACA’s 5th annual air cargo industry sustainability survey. Only 53% have a dedicated sustainability team, just 42% allocate a specific budget for sustainability, and a mere 32% are actively engaged in SAF deployment.

However, carbon offset use stands slightly higher at 35%. This measured progress comes despite strong executive-level support—96% of respondents say their CEO backs sustainability efforts, 88% cite CFO involvement, and 94% believe sustainability is as important, if not more, than it was last year. Currently, the industry’s top focus is on energy optimisation, with 72% prioritising it as a key strategy for cutting both emissions and costs.

Fleet modernisation and vehicle utilisation optimisation are also emerging as critical strategies in the industry’s decarbonisation efforts. 88% of companies have prioritised fleet modernisation, investing in newer, more fuel-efficient aircraft to lower emissions. At the same time, 93% of respondents are actively working on vehicle utilisation optimisation, improving asset management and operational efficiency.

“The finance industry is moving away from the SAF sector, not towards it.”
Julie Kitcher, Airbus

This focus on modernising fleets and optimising asset utilisation underscores the industry’s commitment to incremental improvements. However, some experts argue that these measures, while essential, are not enough to drive the transformative change aviation needs

The need for disruption: Exploring alternative solutions
While SAF is seen as an incremental step towards sustainability, some industry leaders believe a true transformation requires deeper technological innovation.

Bertrand Piccard, Chairman of the Solar Impulse Foundation, criticised the aviation industry’s slow pace of innovation: “Innovation stopped 60 years ago. Planes now look the same as 60 years ago. Of course, they have become safer, more efficient, consume less fuel, and are optimised, but they look the same.”

He argued that a fundamental shift is necessary: “Is SAF a disruption? No. SAF is a way to continue optimisation. There will be planes looking exactly the same that run on SAF.” Instead, he suggested that hydrogen-powered, electric, and even solar-powered planes could be the real game-changers.

Airbus is already working towards hydrogen-powered aviation through its ZEROe project. Glenn Llewellyn, VP of the initiative, explained: “We have decided to move ahead and focus our attention on fuel-cell propulsion systems and liquid hydrogen storage. This combination will allow us to deliver a full-electric aircraft.”

While hydrogen technology is promising, the industry still lacks the necessary infrastructure and regulatory frameworks to support large-scale hydrogen-powered aviation.

Wings of tomorrow: The role of aircraft design in sustainability
Beyond fuel alternatives, innovative aircraft design plays a crucial role in making aviation more sustainable. Airbus and Boeing are investing heavily in new aircraft architectures that prioritise efficiency and reduce emissions.

The “Wings of Tomorrow” initiative by Airbus is a prime example of such efforts. This project focuses on developing ultra-efficient wing structures that enhance aerodynamics, reduce drag, and improve fuel efficiency. The use of advanced materials, such as composite structures and lightweight alloys, further aids in reducing aircraft weight, leading to lower fuel consumption.

Mark Bentall, Head of Research & Technology Programme at Airbus, emphasised the importance of design in sustainability: “We need to rethink aircraft from the ground up. Blended-wing body designs, active wing controls, and advanced propulsion systems will revolutionise aviation in the coming decades.”

Boeing, on the other hand, has been working on its Transonic Truss-Braced Wing (TTBW) concept, which aims to create aircraft with extended wingspans and greater aerodynamic efficiency. NASA has partnered with Boeing to test these designs, which could lead to significant fuel savings and reduced emissions.

These design innovations, when combined with alternative fuel sources and operational efficiencies, could bring aviation closer to its sustainability goals.

Carbon removal and operational efficiencies: Additional pathways to sustainability
Beyond alternative fuels, other strategies to reduce aviation’s environmental footprint include direct carbon removal and operational efficiencies.

Gabrielle Walker, Co-founder and Chief Scientist at CUR8, emphasised the need for carbon removal in addition to SAF. She mentioned that SAF along with carbon removal is essential for decarbonising the sector. Adding to that Vanessa Hudson, CEO of Qantas Airways mentioned, “In the future, consumers are going to make sustainable choices even for aviation, including booking tickets, even if it requires paying a green premium.”

Operational improvements can also significantly cut emissions. Bentall suggested that aircraft could be redesigned to monitor atmospheric conditions in real time, reducing contrail formation, which contributes to global warming.

“Currently, aircraft are not designed to monitor atmospheric conditions effectively. The existing models are big and expensive, not a practical solution for regular flights. We need to develop models that use the best weather data to predict and avoid high-risk zones for contrails and turbulence,” he noted.

The economic and social implications of aviation’s green transition
While sustainability is a pressing goal, the economic and social implications of decarbonisation cannot be overlooked. Qantas’s Hudson pointed out that the SAF industry could create new employment opportunities: “SAF can open up a new industry and create jobs.”

Schmidt of RSB emphasised the broader benefits of SAF beyond aviation: “Look at regions like Southeast Asia, where agricultural residue from rice production is currently burned, impacting air quality. If we use that residue as feedstock for SAF, it improves air quality and decarbonises aviation while reducing public health costs.”

However, many challenges remain. Airbus’ Head of SAF and CRD, Julien Manhes noted that the lack of clear demand signals from airlines and regulatory support is slowing SAF adoption: “I have spoken to many oil and gas companies. They know how to fulfill a demand, but there is no solid demand.”

“We need to make planes that burn less fuel and be more efficient, ensure better air traffic management, use fuels that put less carbon in the air.”
Guillaume Faury, Airbus

Regulatory frameworks and financial incentives will play a crucial role in determining the future of aviation sustainability. Airlines and manufacturers continue to call for stronger policy support to bridge the cost gap between SAF and conventional jet fuel.

A multi-faceted approach to aviation sustainability
The controversy surrounding SAF underscores the broader challenges of making aviation truly sustainable. While SAF is a key component of the industry’s decarbonisation strategy, it is not a silver bullet. The transition to a greener aviation sector requires a combination of solutions, including:

• Greater investment in hydrogen and electric aviation
• Carbon removal technologies
• Improved operational efficiencies
• Supportive regulatory and financial mechanisms

As the Airbus CEO summarised: “We can make hydrogen-powered planes that work. But to scale up, we need commercially viable aircraft, a regulatory framework, and a hydrogen ecosystem at scale.”

While the road ahead is complex, collaboration between governments, financial institutions, and the aviation industry will be essential to accelerating sustainable aviation solutions. Whether SAF, hydrogen, or another breakthrough technology becomes the dominant force in the coming decades, one thing is clear: aviation must evolve to meet the environmental and economic demands of the future.