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2021 CORSIA Reporting: What you need to know


We remind you that the pilot phase of CORSIA began on the 1st of January 2021. This brought in several changes from the 2019-2020 baseline period, most notably in the start of offsetting requirements on particular routes, changes in the eligibility of use of the ICAO’s CERT tool for simplified monitoring and reporting, and deadline changes. This article discusses the changes in detail.

Applicability of offsetting on routes

During the pilot phase and the first phase, offsetting requirements will only be applicable to flights between States that have volunteered to participate. The list of voluntarily participating States during the 2021 reporting year is available in this ICAO document referenced in Annex 16, Volume IV. Therefore, offsetting will apply only on international flights operated between two States appearing in this list.

For example:

Departure Arrival Subject to CORSIA reporting in 2021? Subject to offsetting requirements for 2021 reporting?
ICAO airport code State ICAO airport code State
EFHK Finland ESSA Sweden Yes Yes
LFPG France NTAA France No No
LIRF Italy DTTA Tunisia Yes No
LTFM Turkey VTBS Thailand Yes Yes
OPIS Pakistan OTHH Qatar Yes No
NVVV Vanuatu NFFN Fiji Yes No
Computing the growth factor & offsetting requirements

As mentioned above, the coverage of emissions by CORSIA offsetting requirements is based on the participation of States in CORSIA and the route-based approach. New entrants and operators with very low international aviation activities are exempted, as explained in detail in the CORSIA SARPs. From 2021 through 2029, 100% sectoral approach (and 0% individual approach) shall be applied. This means that aeroplane operators will need to offset a certain percentage of their emissions on routes subject to offsetting requirements, and that percentage will be equal to the sectoral growth factor.

Sectoral Growth Factor

The sectoral growth factor is calculated by considering the total emissions of all aeroplane operators (“the sector”) on routes covered by the offsetting requirements in a given year, and the baseline emissions on the same routes, as described below.


SGFy - Sector’s Growth Factor
SEy - Total sectoral CO2 emissions covered by offsetting requirement (OR) in the given year y
SEB,y - The baseline total sectoral CO2 emissions on routes subject to the offsetting requirement in the given year y. During the pilot phase, the baseline will be equal to the 2019 emissions, while for the first and second phases, baseline will be equal to the average of 2019 and 2020 emissions (unless this is modified later by ICAO).

CO2 offsetting requirements

During the 2021-2029 period, the sectoral growth factor of a given year is multiplied by an operator’s emissions on routes covered by CORSIA offsetting requirements in that year, to calculate that operator’s offsetting requirement for the year.


ORy - Aeroplane operator’s offsetting requirements in the given year y
OE - Aeroplane operator’s CO2 emissions covered by offsetting. During the pilot phase, States have the flexibility in choosing the formula having either:
  • the operator’s emissions in year 2021, 2022 or 2023; or
  • the operator’s emissions referring to a single year of 2020.
SGFy - Sector’s Growth Factor
Reporting fuel consumption for the 2021-2035 period

During the baseline period 2019-2020, the use of CERT for CO2 Estimation & Reporting was possible only if the operator reported fewer than 500 000 tonnes CO2 on international routes during the reporting year. With the start of the offsetting period of CORSIA, this rule has been amended.

Starting from the 2021 reporting period, aeroplane operators with annual CO2 emissions from international flights subject to offsetting requirements greater than or equal to 50 000 tonnes, shall use a Fuel Use Monitoring Method. For international flights not subject to offsetting requirements, the aeroplane operator shall use either a Fuel Use Monitoring Method, or the ICAO CORSIA CO2 Estimation and Reporting Tool (CERT).

Aeroplane operators with annual CO2 emissions from international flights subject to offsetting requirements of less than 50 000 tonnes, shall use either a Fuel Use Monitoring Method or the ICAO CORSIA CO2 Estimation and Reporting Tool (CERT).

Important dates for 2021 reporting

Non-EU based operators must submit the 2021 Emissions and Verification Reports to their respective State authorities by 30th April 2022. States authorities shall submit required information regarding CO2 emissions for 2021 to ICAO by 31st July 2022. Following this, ICAO will compute the sectoral growth factor by 31st October 2022 and provide the information to States, who then proceed to calculate the offsetting requirements for 2021 for each of their aeroplane operators. The operators will be informed of the offsetting requirements by 30th November 2022. The cancellation of emission units for the 2021-2023 reporting period must be done by the 31st of January 2025 or 60 days after the State informs the operator of their final offsetting requirements.

It is important to note that if the 2021 emissions on eligible routes do not exceed the baseline 2019 emissions, there will be no offsetting obligation for 2021, which is highly likely to be the case.
For any queries about the changes in CORSIA in 2021, or any other questions, do not hesitate to contact us at corsia@verifavia.com
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