CORSIA backers push airlines to stay committed as emissions unit supply lags

Supporters of the carbon offsetting and reduction scheme for international aviation want airlines to stay committed to the global market-based mechanism. Work continues on closing a gap in the supply of eligible emissions units before compliance becomes mandatory in 2027.

ICAO member states endorsed CORSIA in October 2016. Emissions growth above 85% of 2019 levels must be offset by purchasing certified eligible emissions units. The second phase starts in 2027, when compliance becomes mandatory for airlines in participating states.

Those units are in short supply. IATA estimates that 200-250 million eligible emissions units will be needed for the first compliance cycle. As of August 2026, it says, only 42 CORSIA-compatible letters of intent had been secured, covering 72 million units. The industry body calls that a substantial gap.

IATA has set up a Supporting Alliance of more than 80 CORSIA stakeholders to address the bottlenecks. At its World Sustainability Symposium in Brussels on 13 October, IATA announced that ICAO has joined the coalition. The alliance is meant to make it easier to authorise emissions units for use under CORSIA and to avoid double-counting. IATA says this will help countries manage the relationship between their nationally determined contributions under the Paris Agreement and the requirements for authorising CORSIA-certified units.

A representative of the industry body said close collaboration is intended to ensure sufficient units are available, and that broader participation will strengthen the path to carbon-neutral growth.