Sustainable aviation fuel remains the most viable near-term lever for cutting aviation emissions, yet the gap between its promise and its present scale has never been more uncomfortable. Global production is expected to reach around 2.4 million tonnes in 2026, representing just 0.8 percent of total aviation fuel use, at a cost to airlines of 4.3 billion dollars, per IATA estimates . That is a record volume, but it is barely a rounding error against the scale of the problem.
The environmental case is well established: SAF can cut life-cycle carbon emissions by 20 to 80 percent compared with fossil Jet-A, depending on feedstock and pathway . Certified pathways under ASTM D7566 include hydroprocessed esters and fatty acids, Fischer-Tropsch synthesis, and alcohol-to-jet, all of which produce drop-in fuels compatible with existing aircraft and infrastructure. This drop-in compatibility is precisely what makes SAF indispensable for long-haul aviation, where electrification and hydrogen remain far off. The fuels work; the challenge lies entirely in producing enough of them at a price the industry can bear.
The economics remain brutal, and the causes are structural rather than temporary. HEFA, the most mature pathway, is feedstock-dominated, with used cooking oil and waste fats comprising over 60 percent of operating expenses, and those feedstocks are finite and increasingly contested . Fischer-Tropsch and ATJ routes are capital-intensive, so minimum selling prices depend heavily on plant scale and capacity factor . Power-to-liquid e-fuels remain significantly costlier still, with production costs of 3.71 to 5.72 dollars per liter, though projected learning curves suggest rapid declines under low-cost renewable power scenarios .
Policy is beginning to move, and the European Union offers the clearest evidence that mandates can work. In the first year of ReFuelEU Aviation compliance, SAF supplied at EU airports reached 1.1 million tonnes, or 2.8 percent of aviation fuel, far exceeding the 2 percent mandate and nearly six times the 2024 volume . Eighty-four percent of that SAF was produced within the EU, and supply reached 121 airports across all 27 member states, up from just 33 airports the previous year . The European Commission projects that production capacity remains on track to meet the 6 percent blending target for Petrochemicals 2030, with roughly 50 synthetic fuel projects awaiting final investment decisions .
Yet the global picture is much less encouraging, and IATA has been blunt about why. Director General Willie Walsh has criticized what he calls ineffectively sequenced government policies and oil companies’ manifest lack of interest, warning that the path to meeting 65 percent of fuel needs by 2050 grows more difficult with each passing year . IATA’s prescription is a particular sequencing: expand renewable energy, ensure open access to fuel infrastructure, establish production incentives and investment frameworks before mandates bite, and create a global book-and-claim system so SAF can be traded across borders .
Feedstock diversification is the other half of the scaling challenge, and it is progressing on several fronts. Municipal solid waste and forestry residues can achieve carbon intensities well below fossil benchmarks, and perennial cellulosic crops offer even lower values. Electro-SAF, produced from renewable power, green hydrogen, and captured CO2, represents the longer-term frontier, with Honeywell’s eFining technology already being deployed across seven planned sites in France, Finland, and the United States, aiming for roughly 200 million gallons annually . But e-SAF’s climate viability depends entirely on the carbon intensity of the electricity supply; a power-to-liquid plant in a high-renewable location can achieve a 27.5 percent well-to-wake reduction against the CORSIA baseline, while one drawing on a carbon-intensive grid can exceed the fossil benchmark entirely .
What the SAF story ultimately shows is that decarbonizing aviation is less a technical problem than one of industrial scale and political will. The fuel works. The engines accept it. The standards exist. The EU has demonstrated that a well-designed mandate can pull supply into the market faster than skeptics predicted. What is missing elsewhere is the policy architecture that makes investment rational and the global trading mechanisms that let SAF reach the markets that need it most. Until those pieces fall into place, SAF will remain what it is today: a proven solution stuck at less than one percent of the problem.