ICAO Joins Global Aviation Carbon Alliance as CORSIA Credit Supply Challenge Grows

The International Air Transport Association announced ICAO’s participation in the Supporting Alliance for CORSIA EEU Supply during its World Sustainability Symposium.

The International Civil Aviation Organization has joined an international effort designed to expand the supply of carbon credits needed by airlines under the global aviation sector's emissions framework, giving the initiative added institutional support as the industry approaches its first major CORSIA compliance deadline in 2027.

The International Air Transport Association announced ICAO's participation in the Supporting Alliance for CORSIA EEU Supply during its World Sustainability Symposium. The Alliance already brings together more than 80 stakeholders working across governments, aviation and carbon markets, with their attention focused on removing practical barriers that restrict the availability of CORSIA Eligible Emissions Units, commonly known as EEUs.

Carbon credit supply grows but remains far below expected aviation demand

CORSIA, the Carbon Offsetting and Reduction Scheme for International Aviation, relies partly on eligible emissions units that airlines can use to meet their carbon obligations. The number of authorized units has been increasing during 2026, providing signs that governments and carbon market participants are making progress in preparing for the initial compliance cycle.

As of August 2026, 42 CORSIA-compatible Letters of Authorization covered about 72 million EEUs, rising sharply from around 40 million units at the beginning of the year. The increase still leaves a large supply challenge because the first compliance cycle is estimated to require between 200 million and 250 million eligible units.

Closing that gap requires faster authorization, clearer national processes and closer cooperation between governments, carbon standards, project developers and aviation stakeholders. Without enough qualifying units reaching the market, airlines could face a constrained pool of credits as they prepare to meet their CORSIA obligations.

Alliance helps governments connect CORSIA with Paris Agreement commitments

A major part of the Alliance's work involves helping countries manage the technical processes required to authorize emissions units for CORSIA use without allowing the same emissions reduction to be counted twice. That issue is particularly important because governments must balance their aviation-related carbon market participation with their own climate commitments under the Paris Agreement.

The initiative supports countries as they navigate the connection between their Nationally Determined Contributions and the authorization of carbon units for international aviation. It also provides access to technical knowledge and practical resources that can help governments participate more effectively in carbon markets and implement Article 6.2 of the Paris Agreement, which provides a framework for international cooperation involving transferred emissions reductions.

ICAO's entry into the Alliance could strengthen coordination between the international aviation regulator, national authorities and carbon market participants during a period when the availability and credibility of eligible credits are becoming increasingly important.

IATA and ICAO call for faster action ahead of 2027 deadline

Marie Owens Thomsen, IATA's Senior Vice President Sustainability and Chief Economist, said the recent expansion in eligible credit supply was encouraging but stressed that growth needs to happen faster. She said ICAO's involvement strengthens the cooperation needed among stakeholders to unlock additional supply and support CORSIA's role as the globally agreed framework addressing emissions from international air transport.

ICAO Deputy Director for Environment Tetsuya Tanaka said the organization is working with governments, aviation companies and carbon market stakeholders to support successful CORSIA implementation. He said ICAO's participation in the Supporting Alliance would strengthen efforts to ensure that enough eligible emissions units become available and contribute to the aviation sector's pathway toward carbon-neutral growth.

With the 2027 compliance deadline approaching and current authorizations covering only a fraction of projected demand, the next stage will depend heavily on how quickly governments can complete authorization processes and bring additional eligible units into the market. ICAO's participation gives the Alliance another route for coordinating those efforts across the global aviation system.