Skip Ribbon Commands
Skip to main content
Access the footer


(Click here for pdf version)

April 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.

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. 

CORSIA in Numbers (As of 30 April 2021)



Voluntary Participation in CORSIA (States for Chapter 3 State Pairs)

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)). As of July 2020, 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. Any other States that also wish to voluntarily participate in the CORSIA offsetting requirements can do so through a notification to the Secretariat by 30 June 2021. More information on benefits of participating in CORSIA can be found here


CORSIA Eligible Emissions Units

The updated ICAO Document CORSIA Eligible Emissions units (March 2021) and Technical Advisory Body (TAB) recommendations in the TAB Report (January 2021) are published on the ICAO website, following the Council approval last month to add Global Carbon Council as immediately eligible to provide emissions units for the purposes of CORSIA during the pilot phase, and the extension of eligible unit dates for American Carbon Registry from "through 31 December 2020" to "through 31 December 2023". More details can be found in the ICAO document CORSIA Eligible Emissions Units available here on the ICAO website.


TAB received public comments for the 2021 assessment of the new applications received from three entities, CERCARBONO, ProClima, and REDD.Plus, as well as two material updates from previously-assessed programmes by December 2020, American Carbon Registry and Verified Carbon Standard. The submitted public comments will be published on the ICAO website.  In addition, TAB has received four material updates from previous-assessed programmes by April 2021, American Carbon Registry, Architecture for REDD+ Transactions, Clean Development Mechanism, and Verified Carbon Standard.


TAB will continue the assessment of above programmes, and recommendations from TAB are expected to be considered by the ICAO Council in October/November 2021. 

CORSIA Eligible Fuels

More details on the ICAO Council's agreement last month on the text of additional new criteria for the sustainability of aviation fuels can be found on C-DEC 222/12 Paragraphs 11 to 13 and Attachment. Further guidance will be developed on the application of such criteria, toward the final Council approval by end of year.


The Council approved default life cycle emission values for 12 new pathways for Sustainable Aviation Fuels production, including feedstocks such as brassica carinata, agricultural residues, forestry residues, miscanthus, and switchgrass. These values can be used to calculate emissions reductions from the use of Sustainable Aviation Fuels, which an aeroplane operator may claim to reduce its CORSIA offsetting requirements. More details can be found in the ICAO document CORSIA Default Life Cycle Emissions Values for CORSIA Eligible Fuels, which is available here.

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. More information can be found here.


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.


In March 2021, the ICAO Council agreed on the process and methodology for the CORSIA periodic review toward 2022, and on the framework for the consideration of inputs from its subsidiary bodies (such as the CAEP and the TAB). Any recommendations by the Council will be forwarded for consideration by the 41st ICAO Assembly scheduled for 2022. 

2021 CORSIA and Other Environment-related Events

Upcoming CORSIA Event:

  • 20-21 July: Seminar on CORSIA


Other Environment Events:

  • 6 May: ICAO Pre-Stocktaking Webinar on "Synthetic fuels for aviation"; more information is available here; information on the full list of ICAO Pre-Stocktaking Webinars is available here
  • 9-14 May: Global Dialogues on the Feasibility of a Long-term Aspirational Goal for International Aviation CO2 Emissions Reductions (LTAG-GLADS); more information is available here
  • 31 August-3 September: ICAO Stocktaking Seminar on Aviation in-Sector CO2 Emissions Reductions; more information is available here
  • 29 November-3 December: Seminar on Green Airports

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.

2021 CORSIA Implementation Deadlines

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

31 May 2021: Aeroplane operators and verification bodies to submit to States verified Emissions Reports and associated Verification Reports for 2020 CO2 emissions.

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.

30 June 2021: States to notify ICAO of any change in their decision to voluntarily participate in CORSIA for the pilot phase.

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.

*According to Annex 16, Volume IV, the baseline emissions for individual operators is needed for 2030 and beyond when offsetting requirements will be calculated based on both the sector growth factor and the operators’ individual growth factor. This provision of Annex 16, Volume IV is not affected by the decision of the ICAO Council in June 2020 regarding the use of 2019 CO2 emissions for 2020 emissions during the pilot phase (2021-2023) of CORSIA. 



The CORSIA Verification Course provides training 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). The next virtual deliveries in English are scheduled for 3-6 May 2021 and
22-25 June 2021. The first virtual delivery in Spanish is scheduled for 21-24 June 2021.


Curso Sobre Verificaciones en el CORSIA ahora disponible en español.


More information  |   Más Información


International Civil Aviation Organization
999 Robert-Bourassa Boulevard, H3C 5H7, Montréal, Quebec, Canada

For more information, visit the ICAO website:

Share this page: