2025 CORSIA periodic review
In March 2023, the ICAO Council requested CAEP to undertake work to support the Council on the 2025 CORSIA periodic review, building upon the 2022 CORSIA review process, with a focus on the assessment of supply, demand, price and cost impact of the CORSIA offsetting requirements, and to perform technical analyses to facilitate the development of a methodology for the periodic review.
In March 2024, CAEP presented to the 231st Session of the ICAO Council a status update on CORSIA analyses with a proposed preliminary schedule of further updates to the CORSIA analyses (C-WP/15562). The updated CORSIA analyses included, inter alia, the development of proxy CAEP/13 CO2 emissions trends; estimations of offsetting requirements through 2035; assessment of regional impacts; estimations of final offsetting requirements after emissions reductions from CORSIA Eligible Fuels; impacts on aeroplane operators; and estimates of costs associated with CORSIA.
The Council reviewed CAEP’s inputs and noted that, in order to support the Council in undertaking the 2025 CORSIA periodic review, CAEP would provide the Council with further updated CORSIA analyses, as well as the schedule of subsequent updates, during the 232nd Session, including updated information on the price of emissions units and CORSIA Eligible Fuels.
In June 2024, CAEP presented to the 232nd Session of the ICAO Council further updates to the CORSIA analyses and to the schedule of subsequent updates (C-WP/15587). The updated CORSIA analyses comprises two main components:
Backward-looking review of CORSIA implementation during its pilot phase (2021-2023); and
Update of the forward-looking assessment presented in previous CORSIA analyses, based on the latest historical data and most recent ICAO forecast including, inter alia, the following elements:
updated estimation of offsetting requirements throughout CORSIA implementation (i.e. up to 2035), including a regional breakdown;
review of relevant technical inputs associated with the outcome of the Third Conference on Aviation Alternative Fuels (CAAF/3) in the context of scenarios for emissions reductions from CORSIA Eligible Fuels; and
cost implications and other considerations in relation to addressing offsetting requirements through the cancellation of CORSIA Eligible Emissions Units vis-à-vis the use of CORSIA Eligible Fuels during CORSIA’s first phase (2024-2026).
The Council reviewed CAEP’s inputs and requested CAEP to provide subsequent updates of the CORSIA analyses to support the Council in undertaking the 2025 CORSIA periodic review, as per the schedule presented by CAEP. The Council also emphasized the need for further information to be provided on the supply, regional distribution and price of CORSIA Eligible Emissions Units and CORSIA Eligible Fuels, as a key input to the 2025 CORSIA periodic review and to any recommendations that would form part of the report by the Council to the 42nd Session of the Assembly.
In October 2024, CAEP provided the 233rd Session of the ICAO Council with a status report on its technical work to support the Council in undertaking the 2025 CORSIA periodic review (C-WP/15630), noting that updates to the CORSIA analyses had been limited in scope since the previous update. The status report is structured in three parts:
Part I: Overview of the main elements of the CORSIA Analyses presented by CAEP to the 232nd Session of the Council, reflecting areas where further CAEP work has led to updates, and with an indication of upcoming updates;
Part II: Status of work undertaken by CAEP in response to requests from the 232nd Session of the Council; and
Part III: Schedule of updates to the CORSIA Analyses for the 234th and 235th Sessions of the Council, as per the schedule presented by CAEP at the 232nd Session.
The Council reviewed CAEP’s inputs and requested CAEP to provide further updates on the CORSIA analyses to support the Council in undertaking the 2025 CORSIA periodic review during the 234th Session, as per the schedule presented by CAEP, with a particular emphasis on matters related to the overall supply, demand and price of CORSIA Eligible Fuels and CORSIA Eligible Emissions Units, as well as the related impacts on the implementation of the scheme.
2022 CORSIA periodic review
Paragraph 17 of Assembly Resolution A40-19 includes a provision that the ICAO Council will conduct a periodic review of the CORSIA every three years from 2022. In this regard, the Council, in June2020, highlighted the importance of undertaking the 2022 periodic review, with technical contribution of the Committee on Aviation Environmental Protection (CAEP), which will offer an opportunity to examine the impact of COVID-19 on CORSIA on various issues, including the impact on the baseline beyond the pilot phase.
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.
In June 2021, the updated CAEP scenario-based analyses on potential impacts of COVID-19 on CORSIA and its executive summary were presented to the 223rd session of the ICAO Council (C-WP/15209).
In November 2021, CAEP’s analyses in support of the 2022 CORSIA periodic review and its Executive Summary were presented to the 224th Session of the ICAO Council (C-WP/15261), including an update of the CAEP analyses of COVID-19 impacts on CORSIA and CAEP’s initial assessment on the implementation of CORSIA, in particular the functioning of MRV provisions.
In March 2022, CAEP provided further inputs to the 225th Session of the ICAO Council regarding the 2022 CORSIA periodic review, including further assessment of COVID-19 impacts on CORSIA (C-WP/15326). In order to facilitate the Council's consideration of these inputs, CAEP structured such inputs in three components, namely:
Key takeaway messages contained in the CAEP inputs listed above were provided to the Council as an Executive Summary.
CAEP also provided, during the 225th Session of the Council, an informal briefing in relation to the CAEP inputs to the 2022 CORSIA periodic review.
In June 2022, the 226th Session of the ICAO Council requested CAEP to undertake further analysis on the impacts of COVID-19 on CORSIA and its baseline, building upon the analyses delivered by CAEP during the 225th Council Session in March 2022. The objective of the requested analysis was to estimate the CORSIA offsetting requirements and the regional breakdown, using the average of 2019 and 2020 emissions as the agreed baseline in Assembly Resolution A40-19, as well as the following scenarios for the CORSIA baseline after the pilot phase (2024 to 2035)
i. 2019 emissions only;
ii. a percentage of 2019 emissions, which reflects an equivalent level to the average of 2019 and 2020 emissions; and
iii. the mid-point between the baseline scenarios i) and ii) above;
This additional CAEP analysis, completed in late June, was presented to the ICAO Council on 24 August 2022 and is now available in the ICAO website here.
The ICAO Council, following consideration of the additional CAEP analysis and other design elements of CORSIA, agreed on a series of proposals for consideration by the 41st Session of the ICAO Assembly, namely:
Use of 2019 emissions as the CORSIA baseline for the pilot phase (2021 – 2023);
Use of 85% of 2019 emissions as the CORSIA baseline after the pilot phase (2024 – 2035); and
Changes to the percentage use of the sectoral and individual operator's growth factors for the calculation of offsetting requirements under CORSIA, as follows:
The 41st Session of the ICAO Assembly considered the Council proposals
and adopted the 
Resolution A41-22 on CORSIA including the design adjustments above, as reflected in
Assembly Working Paper A41-WP/659, available at the ICAO A41 website.
