Aviation climate plans often lead with a single percentage. That number is only useful if you know which flights it covers, whether it refers to fuel or emissions, how much fuel it represents and what energy is needed to produce it. For long-haul aviation, aircraft renewal and the airports chosen for deployment matter just as much.

Begin with flights, not the headline target

EUROCONTROL’s Think Paper #22, published on 17 October 2024, defines long-haul flights as journeys of more than 3,000 kilometres. They account for less than 10% of all departures, yet produce more than 50% of aviation’s carbon emissions. The paper estimates that their share could rise to about 56% of aviation emissions by 2050.

That contrast is the first useful test. A measure aimed at long-haul operations may affect a small share of departures while addressing a large proportion of the sector’s carbon output. Before judging the ambition of a plan, identify its geographic area, route length and operational scope. A percentage attached only to total flights can conceal whether the proposal reaches the routes responsible for most of the emissions.

Turn the fuel percentage into tonnes

ReFuelEU Aviation was adopted in Europe on 9 October 2023. The targets cited by EUROCONTROL are a 2% sustainable aviation fuel share in 2025, 6% in 2030 and 70% in 2050. These are blend mandates: they do not mean that every aircraft will run entirely on SAF.

The next step is to calculate what the percentage means in physical fuel. For its 2050 scenario, the paper estimates annual ECAC aviation fuel demand at about 61 million tonnes. Long-haul flights would use 34 million tonnes, roughly 56% of the total. Applying a 70% ReFuelEU blend to that long-haul demand gives approximately 24 million tonnes of SAF, alongside 10 million tonnes of conventional aviation fuel.

The SAF estimate is split approximately evenly between 12 million tonnes of bio-SAF and 12 million tonnes of synthetic SAF. Those figures provide a consistency check for any announcement using the 2050 target. If it gives a future SAF percentage but no underlying fuel volume, the scale of the long-haul contribution remains unclear.

The distinction also prevents a common misunderstanding: a blend target describes the composition of fuel supplied under the mandate, not a direct percentage reduction in emissions. A serious assessment therefore keeps the fuel share, the total fuel demand and the resulting emissions effect as separate figures.

Trace the fuel back to its power demand

SAF is not only a supply question. Using the FuellingDecarb module of EUROCONTROL’s FlyingGreen platform, the study estimates that producing the projected bio-SAF, synthetic SAF and their co-products would require about 870 terawatt-hours of electricity each year. Around 685 TWh would support the fuels themselves and 185 TWh would support co-produced products.

EUROCONTROL compares that requirement with 73 nuclear reactors, 8,157 offshore wind turbines or a photovoltaic area measuring 43 kilometres by 43 kilometres. The paper also places it at 24% of current ECAC electricity production. These comparisons do not choose a preferred energy source. They show why a fuel mandate needs to be read alongside an energy plan: the fuel target carries a substantial electricity requirement in the modelled scenario.

Check the present supply position before treating a long-term target as secured. The paper says SAF represents 0.05% of European aviation fuel consumption. It estimates potential European production capacity at 2.3 million tonnes per year, which would cover only 7% of 2050 long-haul needs if all of that capacity were dedicated to aviation. The 2050 blend target is therefore an objective against which production must be built, not evidence that the necessary supply already exists.

Put fleet renewal beside SAF

The study assigns aircraft replacement a separate role. Replacing long-haul aircraft more than ten years old would reduce emissions from the long-haul fleet by 10.4% in the modelled scenario. It would reduce total ECAC aviation emissions by 5.4% and lower the amount of SAF required.

When reading a climate plan, separate the result attributed to alternative fuel from the result attributed to fleet renewal. Otherwise, a combined reduction can make the fuel measure appear to carry the entire outcome. The aircraft age threshold is specific to the scenario, so it should be presented as a modelled assumption rather than a universal replacement rule.

Technology availability narrows the choice for the routes in question. Electric and hydrogen aircraft are progressing for short-haul operations, but EUROCONTROL says they are not yet realistic for long-haul flights. For those longer routes, a plan built around SAF and newer aircraft is addressing a different technical problem from one focused on short-haul electrification or hydrogen.

Check where the fuel will be used

Deployment does not necessarily have to be uniform across every airport. Subject to sufficient production and supply, EUROCONTROL says a 20% SAF blend at five airports, a 12.5% blend at 20 airports or an 11% blend at 34 airports could deliver the same environmental benefits as a 10% blend across all 2,165 ECAC airports.

This comparison helps test the implementation section of a plan. A concentrated rollout may simplify supply at selected airports, while a broad rollout spreads access across the network. Neither approach is automatically preferable: the paper’s equivalence applies only if the required production and distribution are available, and the airport count changes the logistics of reaching the stated blend.

Look for the proposed airport network before assuming that a regional target will be experienced uniformly by airlines or passengers. The location of supply is part of the plan’s feasibility, not a detail that can be separated from the percentage.

Use a fixed reading order

For each announcement, record the route and geographic scope first. Then note whether the headline percentage refers to fuel, emissions or departures. Convert it into an annual fuel volume, check the electricity needed to produce that fuel and compare the result with the plan for aircraft renewal. Finish by examining which airports are expected to receive the fuel and whether the proposed distribution matches the stated scope.

Keep the conclusion at the level supported by the model. EUROCONTROL’s paper provides a systems estimate for ECAC aviation, including fuel, electricity, co-production and fleet scenarios. It does not turn those estimates into a guaranteed outcome for one airline, one airport or one passenger journey.

The practical decision is straightforward: treat a SAF target as a complete long-haul decarbonisation plan only when its volume, energy requirement, fleet assumptions and deployment path are connected. If one of those links is missing, the figure may still describe a partial measure, but it does not by itself account for the full challenge.

Official sources

Primary source: Official source: eurocontrol.int