Authorisation, not producer capacity, now sets the ceiling on supply of CORSIA-compliant carbon credits for international airlines, according to analysis published by Air Cargo Week.

The Carbon Offsetting and Reduction Scheme for International Aviation, the ICAO-administered offsetting framework that obliges carriers from participating states to compensate growth in international CO₂ above a 2019 baseline, divides compliance into phases. Phase 1, running through 2026, has already drawn airlines into procurement for approved emissions units while the pool of credits eligible for retirement against the scheme has tightened.

The piece argues that project developers stand ready to issue credits against approved methodologies, but the scheme's filtering on host-country authorisations and ICAO programme recognition determines which of those units airlines can actually retire. Supply is split between physical output and usable supply, with the binding constraint sitting in the second of the two.

What does the authorisation gap mean for operators?

• Volume is no longer the variable. Developers continue to register projects and issue credits against approved methodologies; most of those units never clear the additional filtering ICAO applies before they enter the airline compliance pool.
• Compliance-cost exposure rises as authorised supply narrows, increasing the per-tonne price airlines pay when they retire eligible units.
• Procurement timing pushes later in the cycle, concentrating demand into a thinner spot market ahead of Phase 1 retirement deadlines.
• Sustainability and treasury teams hedging Phase 1 exposure face a narrower eligible pool than they could access in the wider voluntary carbon market.

The split is most consequential for carriers that structured early forward purchases on the assumption that voluntary-market liquidity would translate directly into CORSIA-eligible supply, and for operators from participating states newly drawn into Phase 1 whose compliance calendars run shorter than those of carriers that joined the scheme's 2021 pilot start.

Why is the pipeline slowing?

ICAO's Technical Advisory Body vets emissions-unit programmes against criteria covering additionality, permanence, host-country authorisation and governance. Each layer of evaluation adds time between a project's registration and its recognition as eligible for airline compliance use. The reading in the piece is straightforward: with producer supply effectively unconstrained, the recognised-units pipeline is the variable that determines compliance-cost outcomes for the sector through Phase 1.

What changes if authorisations accelerate?

Faster recognition of high-integrity programmes and more predictable processing of host-country letters of authorisation would widen authorised supply without requiring any increase in developer activity — directly easing unit-price pressure on airlines. The pace at which ICAO and its member states clear that pipeline before the Phase 1 retirement deadlines close will shape compliance-cost outcomes for international operators over the next two reporting cycles.