The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is the only globally agreed market-based mechanism to manage CO2 emissions from international aviation. To meet the requirements of the first phase of CORSIA, airlines are expected to purchase and cancel more than 200 million CORSIA Eligible Emissions Units (EEUs) by January 2028.
The IATA Aviation Carbon Exchange (ACE) will play a key part in making these EEUs available to airlines globally, including through a procurement event it is hosting on the platform during November.
We talked with Michael Schneider, Assistant Director, Sustainability Programs at IATA, to delve into CORSIA and the need for EEUs.
We as an industry remain committed to reaching net-zero carbon emissions by 2050. A key transitional element in achieving this is CORSIA, which is the principal market-based measure for international aviation designed to stabilize net CO2 emissions.
CORSIA is designed to address emissions that cannot yet be eliminated through SAF, technology, other in-sector measures or operational improvements. Under CORSIA, airlines must purchase and cancel EEUs to offset the increase in CO2 emissions covered by the scheme.
While States’ participation has been voluntary during the first phase, from 2027 demand for EEUs will grow significantly as CORSIA moves into its mandatory phase, with major aviation markets including China, India, and Brazil joining and the scheme covering around 86% of international aviation emissions.
To date, the challenge has been limited supply. In June 2026, through the Supporting Alliance for CORSIA EEU Supply, stakeholders from across the CORSIA ecosystem came together to help boost the availability of 225-250 million CORSIA EEUs by spring 2027. We are now beginning to see results on the supply side, with increasing volumes of EEUs coming to market from various countries.
As mentioned previously, we also expect demand for EEUs to grow significantly as CORSIA moves into its mandatory phase from 2027.
To meet the requirements of the first phase (2024-2026), airlines are expected to purchase and cancel more than 200 million CORSIA EEUs by January 2028. That figure could increase to nearly 2 billion EEUs by 2035, thus raising an estimated $120 billion in climate finance.
To keep the market in balance, we will clearly need even more EEUs to come to market to meet that demand. That makes stability and clarity around carbon markets essential, giving projects and investors the confidence to bring forward the supply airlines will need.
Launched in 2020, ACE provides easy access to a large, centralized marketplace for CORSIA-eligible EEUs and voluntary carbon credits. Through ACE, we provide transparent pricing and a wide range of transaction options to make it easier for airlines to buy, cancel, and manage their EEUs.
To help airlines meet their obligations under the first phase of CORSIA, we have opened a procurement event that will run on the ACE platform until 27 November. We have made more than 2.5 million EEUs available, including credits from projects in Guyana, Nigeria, and Rwanda. The procurement event is being held in partnership with Xpansiv and is open solely to airlines.
> Find out more about Aviation Carbon Exchange (ACE)
