In 2016, Governments adopted CORSIA, the Carbon Offsetting and Reduction Scheme for International Aviation, to stabilize net CO2 emissions from international aviation from 2021.

CORSIA has applied to international aviation since 1 January 2019 when all airlines were required to report their CO2 emissions on an annual basis. From 1 January 2021, international flights will become subject to offsetting obligations.

Offsetting is not intended to replace efforts to reduce the sector’s carbon emissions through technology, operational and infrastructure advances. CORSIA will not make fuel efficiency any less of a day-to-day priority for airlines.


Border closures, flight restrictions, travel advisories, and social distancing measures implemented in response to the global COVID-19 pandemic have resulted in an unprecedented decline in aviation activity.

Such a severe shock to the international air transport system was not anticipated when CORSIA was developed. As a result of the crisis, the method used to determine the baseline of the CORSIA scheme - an average of 2019 and 2020 emissions - no longer reflects the target agreed by governments in ICAO. Instead of stabilizing emissions at pre-crisis levels, it would lower the baseline to a level equivalent to the emissions from international aviation in 2014.

IATA is highly concerned that if the stringency to be pursued through CORSIA and impact on international civil aviation are much higher than originally forecast and no longer reflect the ICAO’s targets, some governments would no longer support CORSIA and participation in the scheme would be lower than expected.

IATA therefore recommends that pre-crisis emissions be used to determine reference level emissions and is calling on ICAO to establish CORSIA’s baseline emissions on 2019 emissions only.

If 2019 emissions are used for the baseline, net CO2 emissions from international aviation would be stabilized at around about 600 million tCO2, which is equivalent to the emissions that IATA had forecast for 2020 prior to the crisis.

CORSIA Position Paper


Carbon Offsetting

Offsetting is an action by a company or individual to compensate for their emissions by financing a reduction in emissions elsewhere. Offsetting and carbon markets are a fundamental component of global, regional and national emissions reduction policies. They have operated for decades for compliance purposes and voluntary emissions reductions and continue to be an effective mechanism to underpin action against climate change.

There are many ways to achieve CO2 reductions that can be used as offsets, many of which also bring other social, environmental or economic benefits relevant to sustainable development. Such offsets can be sourced from various types of project activities, including, for example, wind energy, clean cooking stoves, methane capture and other emissions-reducing or avoidance projects.

Environmental integrity

On 16 March 2020, ICAO approved the first emission units that can be used for compliance during the pilot phase of CORSIA (2021-2023). These decisions are guided by eligibility criteria. to guarantee that emissions units deliver the desired CO2 reductions. The criteria are based on principles commonly applied under existing trading mechanisms and well-accepted carbon offset certification standards.

The decision of ICAO only allows the use of offsets issued from projects that started their first crediting period from 1 January 2016 and which represent emission reductions achieved through 31 December 2020.  

Environmental impact of CORSIA

CORSIA is a global scheme which will result in greater levels of CO2 mitigation in international aviation than could be achieved through domestic policy measures. It is forecast that CORSIA will stabilize net CO2 emissions from international aviation at around about 600 million tonnes of CO2.

IATA estimates that, without CORSIA, the CO2 footprint of international aviation would increase from 600 million tonnes of CO2 in 2020 to almost 900 million tonnes of CO2 by 2035.

A multilateral approach

On 27 June 2018, ICAO adopted the international Standards and Recommended Practices (SARPs) for CORSIA as Annex 16, volume IV, to the Chicago Convention.

The adoption of global standards for CORSIA ensures the necessary level of uniformity in regulations which our industry needs. Uniformity is not only key to prevent market distortions, but also to preserve the environmental integrity of CORSIA.

In order to avoid a patchwork of uncoordinated regional and domestic policies for international aviation, political agreement for CORSIA was achieved on the condition that CORSIA would be the only market-based measure applied to international flights and on the basis that emissions should not be accounted for more than once. Unfortunately, the success of CORSIA may be jeopardized by the national policies of some states. Of particular concern, is the action of some states in applying or considering the application of a carbon pricing instrument or ticket tax to address emissions from international aviation, on top of CORSIA. Such policies do not only conflict with the international commitments of these states, they also undermine multilateral efforts to deal with climate change and put at stake the credibility of the global approach, potentially compromising the international support for CORSIA at a critical time for its implementation.

Guidance materials & support

Under CORSIA, all operators with annual emissions greater than 10,000 tonnes of CO2 will have to report their emissions on an annual basis, with monitoring starting from 1 January 2019 (international flights only). Resources are provided below to assist operators comply with CORSIA.

Stay informed

Please let us know if you wish to stay informed about CORSIA and receive regular updates on new capacity-support activities and materials. To sign up, please send us a brief message at

Airline Handbook on CORSIA

The IATA Airline Handbook on CORSIA is intended to provide information to airlines on the main elements of CORSIA and on requirements to comply with the scheme.

Download the IATA Airline Handbook on CORSIA: 4th Edition August 2019.

You will also find additional guidance on CORSIA in the ICAO Environmental Technical Manual on the ICAO website.