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, Low-carbon business 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 rationale is well established: depending on feedstock and pathway, SAF can reduce life-cycle carbon emissions by 20 to 80 percent compared with fossil Jet-A . 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. That compatibility is exactly why SAF is indispensable for long-haul aviation, where electrification and hydrogen remain distant prospects. 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 alcohol-to-jet routes are capital-intensive, making minimum selling prices highly sensitive to 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 domestically, and supply reached 121 airports across all member states, up from 33 the year before . The European Commission projects that production capacity remains on track to meet the 6 percent blending target for 2030, with roughly 50 synthetic fuel projects awaiting final investment decisions .
Yet the global picture is far less encouraging, and IATA has been blunt about the cause. 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 specific sequencing: expand renewable energy supply, guarantee open access to fuel infrastructure, put production incentives and investment frameworks in place before mandates bite, and build a global book-and-claim system so SAF can be traded across borders regardless of where it is produced or used .
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 electricity, green hydrogen, and captured CO2, represents the longer-term frontier, with Honeywell’s eFining technology already being deployed across seven planned facilities in France, Finland, and the United States, targeting around 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 .
Ultimately, what the SAF story reveals is that decarbonizing aviation is less a technical problem than a problem 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.