Aviation's carbon scheme
goes mandatory in 2027

The Carbon Offsetting and Reduction Scheme for International Aviation was adopted by the International Civil Aviation Organization in 2016 and is written into Annex 16, Volume IV to the Chicago Convention. Its aim is to hold the net CO₂ emissions of international aviation at a baseline level, now set at 85% of 2019 emissions, while traffic grows. Airlines do that by buying and cancelling eligible carbon credits for the growth above the baseline, and by using eligible lower-carbon fuels, which reduce what they have to offset. Domestic flights are outside it; they belong to national policy.

Unlike the EU's CBAM, where carbon credits cannot be used at all, CORSIA is built on them. That makes it the compliance market a Gulf carbon marketplace was made for, and the one where eligibility rules matter more than anywhere else.

• Operators. Any aircraft operator with international CO₂ emissions above 10,000 tonnes a year, flying aircraft over 5,700 kg maximum take-off mass. Humanitarian, medical and firefighting flights are excluded; a new entrant is exempt for its first years or until it reaches a share of sector emissions.
• Routes. Offsetting applies to flights between two States that are both in the scheme. Until the end of 2026 that is the volunteering States; from 1 January 2027 it is every State except those exempted, and the exempted States may opt in.
• Monitoring is universal. Every operator above the threshold has had to monitor, report and verify its international CO₂ since 2019, whether or not its routes carry an offsetting obligation. The verified emissions report goes to the operator's State each year.
• The Gulf. The UAE has volunteered since the pilot phase; the region's hub carriers fly almost entirely international networks, so from 2027 close to all of their traffic sits inside the scheme.

Two consequences follow. First, the requirement for the 2024 to 2026 period is already largely determined by traffic that has flown; what remains open is the price of the units and whether enough eligible supply exists by 31 January 2028. Second, because the factor is sectoral until 2030, an airline cannot reduce its 2024 to 2029 obligation by growing slowly; it can only reduce it with eligible fuel or pay for it with eligible units.

ICAO's Technical Advisory Body assesses carbon-crediting programmes against the CORSIA Emissions Unit Eligibility Criteria and approves them for a given phase, sometimes with conditions. For the first phase the American Carbon Registry and Architecture for REDD+ Transactions were approved first, and other programmes, including Verra's VCS, Gold Standard, Climate Action Reserve and the Global Carbon Council, followed with full or conditional approval for defined scopes. Programme approval is only the first gate. A unit is eligible only if it also:

• comes from an activity and vintage inside the window ICAO sets for that phase;
• carries a letter of authorisation from the host country under Article 6 of the Paris Agreement, with a corresponding adjustment so the reduction is not also claimed against that country's national target;
• is issued, tracked and cancelled in a registry the programme operates to CORSIA standards, with the cancellation attributed to the operator and the compliance period;
• has not been used, retired or cancelled for any other purpose.

1. Airlines: quantify the 2024 to 2026 requirement now, not in 2027

The verified emissions for 2024 and 2025 exist; 2026 is a forecast. Apply the published growth factors, net off any eligible fuel, and you have a tonnage to procure before 31 January 2028. Procure in tranches; the eligible market is thin and a single late order moves the price.

2. Airlines: buy eligibility, not labels

Write the four eligibility conditions above into the purchase contract, require the letter of authorisation and the registry attribution as conditions of payment, and keep the evidence for the State's compliance check.

3. Project developers: pursue host-country authorisation

A programme-approved project without a letter of authorisation sells into the voluntary market. The same project with one sells to a compliance buyer with a deadline. Engage the host government early; the process is slow and political.

4. Lessors, fuel suppliers and corporate travel buyers: know your exposure

Aircraft leases increasingly carry environmental covenants; fuel supply agreements are being asked for eligible-fuel certification; large corporate travel accounts want to know what their carrier's compliance costs will do to fares. None of these needs a credit purchase, all of them need an informed answer.

5. Everyone: keep CORSIA claims separate from voluntary claims

A unit cancelled for an airline's compliance is spent; nobody else may claim it. A corporate that buys eligible units for its own net-zero claim is taking supply the airline needed and should say so honestly in its own reporting.

We do not verify emissions, calculate an operator's requirement or file with any civil aviation authority. What we do is source and screen credits against the CORSIA eligibility conditions, so a buyer sees the programme, the vintage, the host-country authorisation status and the registry attribution before committing, and a developer with authorised units reaches the buyers who need them.

• Eligibility flags on every listing, so a credit bought for CORSIA is authorised and a credit bought for a voluntary claim is not mistaken for compliance stock.
• Managed procurement in tranches for operators facing the 31 January 2028 deadline, including forward offtake from developers seeking authorisation.
• Emissions and obligation tracking in Carbon Management, where a CORSIA requirement sits next to any voluntary commitment.
• Companion explainers on the other two regimes a Gulf group may face: EU CBAM and the UAE National Register for Carbon Credits.