Academy
Glossary
48 terms buyers meet, defined plainly and grouped by what you are trying to understand. Where the Academy teaches a term properly, the definition links to the lesson.
The mechanism
How a reduction reaches a buyer who never touches the fuel.
- Book and Claim
- A chain of custody model that separates the environmental benefit of a lower-emissions fuel from the physical fuel. A buyer can fund it in one place and claim the verified reduction, even where the fuel itself isn't available.What is Book and Claim →
- Environmental attribute
- The environmental characteristics of a batch of fuel, held separately from the fuel itself: the lifecycle emissions reduction, the feedstock, the production pathway and the certification behind it. Book and Claim lets the attribute travel to the party that makes the claim, while the fuel goes wherever it is most efficient to burn it. The attribute is retired once, by one owner.What is a SAF certificate →
- SAF certificate (SAF Scope 3 certificate)
- The instrument that records the verified reduction from a batch of SAF and assigns it to one owner. The corporate version records a Scope 3 reduction.What is a SAF certificate →
- BCU (Book and Claim Unit)
- How SAF is registered on a registry before its attributes are transferred and retired. One BCU is one tonne of neat, certified product.Book and Claim, step by step →
- Chain of custody
- The tracked, audited path from the fuel to the certificate, so the reduction is counted once and owned by one party. Book and Claim is one of three recognised models, alongside physical segregation and mass balance.Book and Claim, step by step →
- Registry retirement statement
- The formal registry record that a defined quantity of SAF was used, assigned to named parties, and retired so it can never be claimed again. It is what the buyer actually receives.Registries, retirement, and counting once →
- Retirement
- The moment a claim becomes valid for reporting. The registry permanently assigns the reduction and takes the unit out of circulation; retired units cannot be resold.Registries, retirement, and counting once →
- Double counting
- The same reduction claimed twice within the same scope. It has three failure modes, double issuance, double use and double claiming, each designed out by registry rules. An airline's Scope 1 claim and a corporate's Scope 3 claim from one batch are not double counting: they are different entries in different ledgers.Registries, retirement, and counting once →
- Insetting
- A reduction made inside your own value chain, where the emissions happen. A SAF certificate is insetting, not an offset and not a carbon credit.Scope 1, Scope 2, Scope 3 →
- Offset
- A reduction bought outside your own value chain, such as funding tree planting or a renewable energy project elsewhere, to counterbalance emissions you have produced. A SAF certificate is not an offset: the reduction happens inside aviation, in the fuel that replaces the fossil fuel you would otherwise have caused to be burned.
- Carbon credit
- A tradeable unit representing one tonne of CO₂ reduced or removed by a project, usually outside the buyer's value chain. A SAF certificate is not a carbon credit. It records the environmental attribute of a specific batch of fuel, evidenced by a registry retirement statement naming the batch, the feedstock and the lifecycle reduction.
- Additionality
- Whether a reduction would have happened anyway. RSB treats this as a category rather than a yes or no. The category reflects the policy and incentives behind the fuel, and is printed on the retirement statement. We sell voluntary volume, beyond what a blending mandate already puts in the supply. The statement records which incentives and mandates a fuel has touched, so a buyer can judge for themselves.Book and Claim, step by step →
Emissions accounting
Whose emission is whose, and where a SAF claim lands.
- GHG Protocol
- The standard defining the Scope 1, 2 and 3 emissions framework used by companies and legislation worldwide.Scope 1, Scope 2, Scope 3 →
- Scope 1
- Direct emissions from sources a company owns or controls, such as an airline burning fuel in its own aircraft.Scope 1, Scope 2, Scope 3 →
- Scope 2
- Indirect emissions from the electricity, heat and steam a company purchases.Scope 1, Scope 2, Scope 3 →
- Scope 3
- All other indirect emissions across a company's value chain. Business travel is Category 6; freight you pay others to move sits in Categories 4 and 9. This is where corporate SAF claims sit.Scope 1, Scope 2, Scope 3 →
- Lifecycle emissions
- Emissions counted across the whole life of a fuel: feedstock, production, transport and combustion combined, rather than only at the point of burning. Every SAF reduction figure is a lifecycle figure.What is a SAF certificate →
- Carbon intensity (CI)
- Lifecycle emissions per unit of energy, usually grams of CO₂ equivalent per megajoule. The fossil jet baseline used in certification is 89 gCO2eq/MJ.Registries, retirement, and counting once →
- Well-to-wake
- The full lifecycle boundary for a fuel, from extracting the feedstock through to burning it in an engine. The counterpart, tank-to-wake, counts only combustion.
The fuel
What SAF is, what it is made from, and how.
- SAF (sustainable aviation fuel)
- Jet fuel made from sustainable feedstocks rather than fossil crude. It reduces emissions on a lifecycle basis, not at the tailpipe: burning it releases carbon that was recently in the atmosphere rather than carbon released from geological storage.Why the fuel can't be where you are →
- Drop-in fuel
- A fuel meeting the same technical standards as conventional jet fuel, compatible with existing aircraft, engines and airport infrastructure with no modification.Why the fuel can't be where you are →
- SBC (synthetic blend component)
- The non-fossil part of the fuel, before it is blended with conventional kerosene.
- CAF (conventional aviation fuel)
- Fossil-derived jet fuel, the baseline against which a SAF reduction is measured.
- Feedstock
- The raw material a fuel is made from, such as used cooking oil, waste fats, agricultural residues or technical corn oil.
- UCO (used cooking oil)
- The dominant feedstock for today's SAF. Supply is limited and heavily traded, which is one reason production cannot scale on this pathway alone.
- HEFA
- Hydroprocessed Esters and Fatty Acids. Today's dominant production pathway, converting used cooking oil, animal fats, tallow and technical corn oil into jet fuel.
- ATJ (alcohol-to-jet)
- A pathway converting ethanol or isobutanol into jet fuel. Approved under the technical standard, with a maximum blend limit.
- Fischer-Tropsch (FT)
- A pathway that gasifies forestry and agricultural residues or municipal solid waste into syngas, then reassembles it into liquid fuel.
- e-SAF (power-to-liquid, PtL)
- Synthetic fuel made from renewable electricity, water and captured CO₂, with no biomass involved. Electricity is the dominant cost, so it depends on cheap renewable power.
- RFNBO
- Renewable Fuel of Non-Biological Origin. The EU's term for e-fuels made using renewable electricity.
- DLUC and ILUC
- Direct and Indirect Land Use Change. Direct: land cleared to grow a fuel crop. Indirect: a switch to fuel crops displaces food production, which clears land elsewhere. Both are counted in a credible lifecycle assessment.
- LCAF
- Lower Carbon Aviation Fuel. A fossil aviation fuel that meets the CORSIA sustainability criteria. Not a sustainable aviation fuel, despite the proximity of the names.
Certification and registries
Who checks the fuel, and where the claim is recorded.
- RSB (Roundtable on Sustainable Biomaterials)
- An independent sustainability certification standard, and one of the schemes recognised under CORSIA. It operates the RSB Book and Claim Registry. Future Energy Global is certified by RSB as a trader.Registries, retirement, and counting once →
- ISCC (International Sustainability and Carbon Certification)
- An independent sustainability and carbon certification standard, also recognised under CORSIA. Future Energy Global is certified by ISCC as a trader.Registries, retirement, and counting once →
- ASTM D1655
- The jet fuel technical standard, in force since 1959, defining composition and properties for jet fuel from any source.
- ASTM D7566
- The standard defining approved production pathways for jet fuel made without fossil input, and the maximum blend percentage for each. Fuel meeting D7566 also meets D1655, which is what makes SAF a drop-in fuel.
- CADO SAF Registry
- The registry operated by the Civil Aviation Decarbonization Organization, underpinned by IATA's SAF accounting methodology. Future Energy Global delivered the first transaction on it, with Microsoft, and appears by name on its public redemptions table.Registries, retirement, and counting once →
- Assure SAF Registry
- A registry operated by 4AIR, focused on business and corporate aviation. The ITOCHU transaction at Tokyo Narita was registered on it.Registries, retirement, and counting once →
- SABA and the SAFc Registry
- The Sustainable Aviation Buyers Alliance, a buyers' alliance that runs the SAFc Registry in the United States.
- SAFc
- A widely used shorthand for a SAF certificate, written with a lowercase c. Buyers search for it, so it is worth recognising, though our own noun is environmental attributes.
Policy and regulation
The mandates and standards that shape demand.
- CORSIA
- ICAO's Carbon Offsetting and Reduction Scheme for International Aviation. Airlines on covered routes offset emissions growth and can reduce that requirement with CORSIA eligible fuel. A fuel's CORSIA certification describes the fuel and is separate from any voluntary claim.
- ReFuelEU Aviation
- EU regulation requiring fuel suppliers to blend a rising share of SAF at larger EU airports. It governs suppliers and airlines, not a corporate's voluntary Scope 3 claim.
- RED III
- The EU Renewable Energy Directive. It sets a substantially higher emissions-saving threshold for qualifying fuel than CORSIA's floor.
- EU ETS
- The EU Emissions Trading System. Airlines surrender allowances for CO₂ on intra-European flights.
- SBTi (Science Based Targets initiative)
- The body that validates corporate emissions targets. Its Corporate Net-Zero Standard version 2, published June 2026, states that targets may be supported by market instruments including commodity certificates on mass balance or book-and-claim chains of custody, subject to its guardrails. The standard permits this route; it does not name sustainable aviation fuel, and version 2 applies to new target submissions from 2028.Scope 1, Scope 2, Scope 3 →
Commercial terms
The finance vocabulary behind getting a plant built.
- Tenor
- The length of a contract, borrowed from aviation leasing and finance. Producers need roughly ten to fifteen years of firm demand to make a new plant bankable; airlines typically commit for one to three.
- Offtake
- A long-term agreement to buy a producer's fuel or its attributes. The firm, long-dated demand that lets a plant get financed.
- FID (final investment decision)
- The point at which a project is genuinely financed and committed, rather than announced. Much announced SAF capacity has not reached it.
Keep going
Definitions are the start, not the point.
The Academy teaches how these fit together: why the fuel is never where you need it, how the settlement works, and what the registry actually proves.