The gap efficiency can’t close
Aviation produces roughly 2 to 2.5% of global CO₂, and that share has stayed broadly flat for decades. Two trends cancel each other out: aircraft keep getting more efficient, and the world keeps flying more. Between 2009 and 2019, aviation’s CO₂ grew 44% despite the efficiency gains. Efficiency is a percentage. Growth is a multiplier.
For medium and long-haul flying, no alternative to a liquid drop-in fuel is expected for at least 15 years, and an aircraft delivered today will still be flying in the 2050s. That is why every serious industry roadmap lands in the same place. Sustainable aviation fuel (SAF) accounts for around two-thirds of the reductions aviation needs by 2050.
How little there is, and where it is
SAF is under 1% of global jet fuel today. To meet 2050 demand, production needs to scale more than 400-fold.
The little that exists is concentrated. SAF is made where feedstock and refining capacity are, in a handful of regions, and supply at most airports is thin or absent. It is a drop-in fuel, meeting the same technical standards as conventional jet fuel and running in existing aircraft, so the barrier is availability rather than compatibility.
The buyer in the wrong place
An airline in Auckland wants to fly on SAF. The fuel exists, in Montana. A company in Dublin with a business travel target meets the same wall: the fuel is real, and it is on the wrong side of the world. Those places are illustrative, but the geography they describe is the market’s daily reality.
Why shipping it is the wrong answer
Physically moving SAF to the buyer is slow and expensive, and it burns fuel along the way, eating into the very benefit being bought. The producer loses too. A refinery can only sell to the airports its trucks and pipelines actually reach, so good production in the wrong place struggles to find its buyer.
ICAO’s own guidance names the answer: separating the claim from the fuel brings logistical efficiency, and it opens the global market to producers wherever they are.
The idea that unlocks it
Renewable electricity solved this problem years ago. Nobody can trace an electron from a wind turbine to their socket, so the market tracks verified certificates instead, with strict rules so each one is counted once. Book and Claim brings the same discipline to fuel. The fuel is used where it makes sense. What travels to you is the verified environmental attribute.
The next lesson walks through exactly how that settlement works, step by step. For the shorter version, start with what Book and Claim is.
It already works
On 19 May 2026, ITOCHU Corporation supplied physical SAF to an airline at Tokyo Narita Airport and provided the environmental attributes of that fuel to Future Energy Global, for use by our airline and corporate clients. The transaction was registered on the Assure SAF Registry.
The aircraft burned the fuel in Tokyo. The verified claim can be reported wherever a buyer has a target. That is the whole point.