The aviation sector says it wants to decarbonise. At the same time, some of the people who run airlines are publicly doubting the very fuel the industry says will get it there: sustainable aviation fuel, or SAF. That contradiction matters. If airlines — the organisations with the money, the routes and the purchasing power — show public scepticism about SAF’s availability, cost and environmental claims, that scepticism can slow investment, confuse regulators and weaken public support for the policies that would actually create more SAF. According to Reuters, some high-profile airline executives have recently questioned whether SAF and the sector’s 2050 goals are realistic, and even dismissed parts of the industry push as fanciful.
This is not a debate about whether SAF can work in an engine. It can. It’s a debate about scale, price and trust. The industry’s own trade body warns the fuel is nowhere near the volumes needed to meet targets; at current rates, it will be a tiny fraction of total jet fuel for years, forcing a hard choice: speed up public support for production, or accept a slower decarbonisation pathway. According to Willie Walsh, director general of IATA, airlines could miss SAF and net-zero targets unless governments, energy companies and investors move faster.
Table of Contents
- What the Evidence Shows: Supply, Science and Cost
- Where SAF Has Worked — and Why Scepticism Persists
- What Comes Next: Fixing Credibility to Speed SAF Uptake
What the Evidence Shows: Supply, Science and Cost
The numbers explain why airlines sound the alarm. Industry tallies and independent analyses place current SAF volumes at fractions of a percent of the world’s jet fuel demand. IATA and other agencies report production measured in hundreds of thousands or low millions of tonnes—far below the scale needed for the sector’s net-zero plans. A report by IATA in 2024 found that while production is growing, it still covers only a tiny slice of airline fuel needs, and that far more biorefineries and investment will be necessary to meet medium-term targets.
On the science side, lifecycle analysis matters. SAF pathways differ: some fuels are made from waste oils (HEFA), others are synthetic fuels produced from hydrogen and electricity (e-SAF), and still others use advanced biofeedstocks. Each pathway yields different greenhouse-gas savings and carries different land-use risks. The International Council on Clean Transportation modelled lifetime fleet emissions and warned that even optimistic SAF rollouts must be paired with other measures—such as fleet renewal, operational improvements, and policy action—to avoid exceeding a net-zero carbon budget. The study highlights why accuracy in carbon accounting, along with transparent and robust sustainability criteria, is essential to building trust, and it details exactly how much SAF could help under varying scenarios.
Cost is the third big reason for scepticism. Producing SAF today is more expensive than fossil jet fuel. Airlines buying the small available volumes are paying premiums, sometimes funded by passenger surcharges or by corporate buyers. Where airlines or governments have stepped in with guarantees or subsidies, supply commitments have followed; where they haven’t, producers find the case for greenfield plants hard to justify. No single stakeholder can close this investment gap alone: producers want long-term offtake contracts; airlines want assurance that prices and supply won’t bankrupt them; governments worry about public costs. This impasse is why industry lobbying often sounds less like an environmental plea and more like a plea for regulatory certainty and public support. Reuters reporting and industry press releases from 2023–2025 capture this tug of war between airlines, oil majors and policymakers.
Where SAF Has Worked — and Why Scepticism Persists
There are real, verifiable successes that show SAF can be used safely and at scale in single flights. In November 2023, Virgin Atlantic operated a transatlantic flight that used 100% SAF in both engines as a demonstration. Company leaders, engineers and some passengers called it a breakthrough: the flight’s sponsors reported measured emissions savings on that routing and framed the mission as a technology demonstration that proved SAF is operationally viable. According to Virgin Atlantic’s public statements, Flight100 saved tonnes of CO₂ on that single flight and provided practical experience landing, refuelling and certifying SAF for a long-haul service. “Flight100 proves that SAF can be used as a safe, drop-in replacement for fossil-derived jet fuel,” said Virgin’s CEO.
Those real successes fuel genuine personal stories. Sir Richard Branson, who flew on Flight100, described the experience as proof that radical collaboration can change what’s possible, and engineers from the University of Sheffield who worked on the project spoke publicly about the practical problems they overcame to make the flight happen. Those are not fictional anecdotes; they are documented, named participants in an industry milestone.
Yet the same flight highlights the gap that fuels airline scepticism: one-off or occasional demonstration flights do not amount to a broad commercial supply. Activists and analysts note that many of these demonstrations have relied heavily on waste feedstocks, which are themselves limited in quantity. Transport & Environment’s 2024 ranking found that most airlines had weak plans for transitioning to SAF at scale, assessing commitments and procurement against what net-zero pathways require. In short, demonstrations prove technical feasibility, but the market realities needed to deliver SAF cheaply and at volume—land, feedstock supply chains, catalytic equipment, electrolytic hydrogen at scale, and capital—remain uneven. The ranking also highlighted that only a minority of carriers were taking the practical, verifiable steps needed to scale SAF, such as long-term purchasing, financing, and supplier partnerships.
The public hears mixed messages. On some days, airline CEOs or industry bodies urge governments to help scale SAF with mandates or price supports. On other days, high-profile executives cast doubt on whether SAF targets are realistic and warn regulators that forcing high blends too quickly could damage airline finances. That public push-and-pull shows up in the press: some industry leaders warn of supply shortfalls, while others argue that mandates are unfair given current production.
What Comes Next: Fixing Credibility to Speed SAF Uptake
If public scepticism from airlines slows SAF, there are concrete ways to restore credibility and unlock supply — and they are practical, not theoretical. First, transparent accounting: everyone needs the same, verifiable numbers on lifecycle emissions and feedstock origins. Third-party registries, clear sustainability criteria and consistent life-cycle analysis methods reduce the suspicion that claims are being overstated. Policymakers and researchers have already called for harmonised LCA rules and registries to track SAF production and use; these governance tools make claims verifiable and disputeable in healthy ways. A report by ICCT and other policy analysis groups has laid out why consistent lifecycle rules are necessary to avoid perverse outcomes.
Second, predictable policy and market signals. Producers will build plants if they can see long-term demand and price support. Governments in some markets are experimenting with mandates, offtake guarantees, and price mechanisms to reduce investor risk, while other countries are slower to act. IATA and national industry bodies have called for clearer policies to mobilise capital — and for oil majors to shoulder a bigger part of the build-out. Where those signals exist, investment follows; where they don’t, tensions between airlines and energy firms deepen. According to IATA, rising production depends on policy support and private investment.
Third, honest public communication. The industry needs to stop oscillating between grand promises and public pessimism. Leaders who publicly dismiss SAF as “nonsense” or say targets are “dying” may be reflecting practical constraints, but their words also risk eroding political will. Balanced messages that explain trade-offs, acknowledge gaps and show when and how problems will be solved build trust more effectively than shorthand scepticism. Media coverage in 2024–2025 shows how mixed messages confuse audiences and delay action.
And perhaps most importantly, pairing short-term realism with long-term ambition. Demonstration flights like Flight100 are crucial proof points; they are the laboratories that show SAF works in practice. But scaling demands financing new plants, securing sustainable feedstocks, and improving social and environmental safeguards so SAF doesn’t swap one problem for another. The way forward is messy and collective: airlines must commit to verifiable procurement plans and long-term contracts, governments must design stable incentives and standards, and energy companies must invest in conversion capacity. Together, those steps would make public scepticism less necessary — and less believable.
Practical Next Steps for Policymakers and Airlines
Harmonise lifecycle rules and registries, establish multi-year offtake frameworks to reduce investor risk, diversify feedstocks (so the sector isn’t reliant on narrow waste streams), and fund public pilot plants in regions that can deliver scale quickly. These are not magic bullets, but they are the levers that can move the market.
If the aviation industry truly intends to meet its climate commitments, it will need both the realism that single flights reveal and the political courage to turn demonstrations into millions of tonnes each year. The choice is not between SAF and other decarbonisation levers — it is about building the trust and supply chains that allow SAF to play the central role science shows it can. According to recent industry reports and analyses, that will require clearer rules, larger investments, and steadier public messaging than the sector has demonstrated so far.
