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June 2021

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is the first global market-based scheme that applies to a sector. It complements other aviation in-sector emissions reductions efforts such as technological innovations, operational improvements and sustainable aviation fuels to meet the ICAO aspirational goal of carbon neutral growth.

102 States Voluntarily Participate in CORSIA


The 40th ICAO Assembly strongly encouraged all States to voluntarily participate in the pilot phase and the first phase of CORSIA (Assembly Resolution A40-19, paragraph 9 c)). Eighty-eight (88) States have volunteered to participate in offsetting CO2 emissions under CORSIA from its pilot phase that started on 1 January 2021. The list of these 88 States can be found here.


The Governments of Bahamas, Barbados, Belize, Cook Islands, Gambia, Grenada, Kiribati, Nauru, Saint Kitts and Nevis, South Sudan, Tonga, Trinidad and Tobago, Tuvalu, and Vanuatu notified the ICAO Secretariat of their intention to voluntarily participate in the CORSIA offsetting requirements from 1 January 2022, bringing the total number of participating States to 102. 

CORSIA in Numbers (as of 30 June 2021)

Under CORSIA, aeroplane operators with international flights are subject to monitoring, reporting and verification (MRV) requirements. As of 1 January 2019, operators are required to monitor their annual CO2 emissions, have them verified through a third-party verification process, and submit them to the States to which they are attributed. States collect emissions data from all their operators and submit consolidated information to ICAO.


In addition to CO2 emissions, States are required to submit information on aeroplane operators attributed to them, and on verification bodies accredited in them. The latest lists of aeroplane operators and verification bodies can be found in the fifth edition of ICAO document "CORSIA Aeroplane Operator to State Attributions" and in the eighth edition of ICAO document "CORSIA Central Registry (CCR): Information and Data for Transparency", respectively. 


Reporting CO2 Emissions through the CORSIA Central Registry (CCR)

In accordance with the provisions of Annex 16, Volume IV, States have to submit CO2 emissions, through the CORSIA Central Registry (CCR), every year starting with the 2019 emissions that were due on 31 August 2020. To alleviate some of the negative impacts of COVID-19, the June 2020 ICAO Council agreed on some flexibility regarding the late submission of 2019 CO2 emissions data and requested the Secretariat to facilitate the reporting working closely with States that had problems meeting the original deadline. As of 30 June 2021, 114 States had submitted their 2019 CO2 emissions through the CCR. Collectively, these States account for more than 95% of the total 2019 RTK. As per the SARPs in Annex 16, Volume IV, the Secretariat will proceed with completing the emissions gap for States that do not submit data through the CCR.



For 2020 CO2 emissions, the deadline for submission is 31 August 2021. With the experience of the 2019 CO2 emissions, States are now in a better position to comply with the CORSIA reporting deadlines. As of 30 June 2021, 18 States have already started the reporting process for 2020 CO2 emissions data through the CCR.



The Secretariat will compile the CORSIA baseline CO2 emissions (taking into account the relevant decisions by the Council in June 2020) aggregated for all aeroplane operators on each State pair in the CORSIA document “CORSIA Central Registry (CCR): Information and Data for Transparency”. The document will be published no later than 30 November 2021 on the ICAO website following its approval by the ICAO Council. 

2021 CORSIA Implementation Deadlines

In accordance with Appendix 1 to Annex 16, Volume IV, the following deadlines apply to 2021:

1 June 2021 to 31 August 2021: States to conduct an order of magnitude check of the verified Emissions Reports for 2020, including any filling in of data gaps in case of non-reporting by aeroplane operators.

1 August 2021: States to obtain and use the ICAO document entitled "CORSIA States for Chapter 3 State Pairs" applicable for the 2022 compliance year.

31 August 2021: Using the CCR, States to submit to ICAO aggregate CO2 emissions per State pair for 2020.

30 September 2021: States to calculate and inform aeroplane operators attributed to them of their average total CO2 emissions during 2019 and 2020.

30 November 2021: Using the CCR, States to update their list of aeroplane operators that are attributed to them, and the list of verification bodies accredited in them.

31 December 2021: States to obtain from the ICAO website and use the ICAO document entitled "CORSIA Aeroplane Operator to State Attributions" summarising a list of aeroplane operators and the State to which they have been attributed.

CORSIA Capacity Building

ACT-CORSIA is the Assistance, Capacity Building and Training programme on CORSIA. It was established in June 2018 and encompasses the CORSIA Buddy Partnerships and all other ICAO outreach initiatives including sample model regulations for CORSIA, frequently asked questions (FAQs), brochure and leaflets, videos as well as CORSIA seminars/webinars and online tutorials.


CORSIA Frequently Asked Questions (FAQs): An updated version of the frequently asked questions (FAQs) on CORSIA, reflecting developments in 2020, is available here.


ACT-CORSIA Buddy Partnerships are the core of capacity building activities. They rely on individual training of CORSIA Focal Points and involves experts from 134 States. In May and June 2021, various activities took place involving Cambodia and Myanmar in partnership with Japan, and Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, North Macedonia, Republic of Moldova and Serbia in partnership with Germany. More information can be found here.


ACT-CORSIA will now focus on CORSIA volunteer States providing training on offsetting compliance through the use of CORSIA Eligible Fuels and CORSIA Eligible Emissions Units.

Navigating CORSIA - A guide to the scheme’s design & implementation

Since the adoption of the CORSIA-related Standards and Recommended Practices (SARPs) in 2018, ICAO has developed the remaining elements needed for the CORSIA implementation.

Click here to watch on the ICAO TV the Navigating CORSIA series of pre-recorded presentations that focus on the status of implementation of CORSIA and provide information on its key design elements.

Click here for an infographic on the status of all implementation elements.

CORSIA Eligible Emissions Units

TAB will continue the assessment of emissions unit programmes, including the four material updates to previously-assessed programmes, American Carbon Registry, Architecture for REDD+ Transactions, Clean Development Mechanism, and Verified Carbon Standard.  TAB recommendations are expected to be considered by the ICAO Council in October/November 2021.


The 26th session of the Conference of the Parties (COP26) to the UNFCCC is scheduled to take place in November 2021. Among the issues to be discussed during COP26 is the implementation of international carbon markets under Article 6 of the Paris Agreement. The UNFCCC pre-sessional period that took place in June 2021 included the discussions on three separate issues: a) guidance on cooperative approaches referred to in Article 6, paragraph 2, of the Paris Agreement; b) rules, modalities and procedures for the mechanism established by Article 6, paragraph 4, of the Paris Agreement; and c) work programme under the framework for non-market approaches referred to in Article 6, paragraph 8, of the Paris Agreement. Summary notes are available here.


Key issues on Article 6 that are of relevance for the work of ICAO on CORSIA include: the avoidance of double-counting; the achievement of overall mitigation of global emissions; levy on credits trading that can fund adaptation efforts; and decisions on whether credits generated under the Kyoto Protocol can continue to apply to emissions targets under the Paris Agreement. ICAO follows closely the developments under the UNFCCC and in particular, on any implications for the implementation of CORSIA and the CORSIA eligible emissions units.

2022 CORSIA Periodic Review

In accordance with paragraphs 9 g) and 17 of ICAO Assembly Resolution A40-19, the ICAO Council has been tasked with undertaking a periodic review of the implementation of CORSIA every three years, starting 2022. In the context of sustainable development of the international aviation sector and improving the effectiveness of the Scheme, the Council is to consider the impact of CORSIA on the growth of international aviation, and to recommend, as necessary, adjustments to the next phase or compliance cycle of CORSIA.
More details on the ICAO Council agreement in March 2021 on the process and methodology for the 2022 CORSIA periodic review can be found on C-DEC 222/12 Paragraphs 9 to 10, including the consideration of inputs from its subsidiary bodies (such as the CAEP and the TAB) and timeline. Any recommendations by the Council will be forwarded for consideration by the 41st ICAO Assembly scheduled for 2022.



In June 2021, the CAEP presented the results of its work to the 223rd session of the ICAO Council (C-WP/15209). The updated CAEP scenario-based analyses on potential impacts of COVID-19 on CORSIA and its executive summary are now available on the ICAO website.



2021 CORSIA and Other Environment-related Events


Save the Date:

  • 6-7 October: ICAO CORSIA Forum to provide an overview of the “state of play” in CORSIA implementation, with a focus on milestones successfully reached thus far, and to serve as a platform for States to share success stories and lessons learned regarding CORSIA implementation. Further details on the programme for the event will be made available here


Other Environment Events:

  • 27 July: ICAO Pre-Stocktaking Webinar on "Infrastructure development for supplying clean energy for air travel"; more information is available here; information on the full list of ICAO Pre-Stocktaking Webinars is available here
  • 10 August: 2021 ICAO Stocktaking preview; more information is available here
  • 31 August-3 September: 2021 ICAO Stocktaking Seminar on Aviation in-Sector CO2 Emissions Reductions; more information is available here
  • 29 November-3 December: Seminar on Green Airports


The CORSIA Verification Training Week will provide you the opportunity to listen to a panel of experts and participate in stimulating discussion on this subject. Participant will also take part in a training course, available in English, Spanish and French, on how to verify CO2 Emissions Reports that have been prepared by aeroplane operators, in accordance with the provisions of the CORSIA Standards and Recommended Practices (SARPs).


> Click here for more information about the CORSIA Verification Training Week



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