Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is a way to manage emissions from the international aviation industry. It’s one way that the International Civil Aviation Organization’s (ICAO) member countries, including Canada, are working towards carbon neutral growth for international aviation from 2020 onwards.

On this page


CORSIA is a global market-based measure that requires operators to cancel emissions units to offset a part of their carbon dioxide emissions.

An “emissions unit” is a certificate that represents a reduction or removal of greenhouse gases by carbon sink in another sector (like energy, waste, or forestry). A “carbon sink” is any reservoir that absorbs more carbon than it releases. Carbon sinks lower the concentration of carbon dioxide in the earth’s atmosphere.

From the start of the scheme, and until 2027, these offsetting rules will only apply to routes between countries that are participating voluntarily. In order for a route to be included, both the arrival and departure countries must be participating in the scheme. Canada volunteered to participate.

By 2027, most countries will have to participate in CORSIA, so these offsetting requirements will apply to most international routes. After 2027, the only international routes not covered will be those to and from countries with low air traffic, or to and from countries that are classified as:

To start, CORSIA sets the amount of emissions an operator has to offset based on their share of all international aviation emissions on covered routes and the sector’s growth after 2020. This growth is calculated by ICAO and based on monitoring, reporting and verification information provided by all countries. Eventually, CORSIA’s emissions obligations will be based on how much each operator’s emissions grow after 2020.

Starting in 2025, and then every three years, operators will have to cancel enough emissions units to match their offsetting obligation for the most recent 3-year period.

Operators can also reduce their need to offset emissions by using CORSIA eligible fuels. The development and deployment of sustainable aviation fuels is one element of the ICAO basket of measures to reduce aviation emissions.

Changes to CORSIA Baseline

The changes to CORSIA baseline are due to impact of COVID19 and first CORSIA review. There was a major drop in international air traffic in 2020. As a result, the International Civil Aviation Organization decided that the value of 2019 emissions will be used for 2020 emissions for the first compliance period from 2021 – 2023 to avoid placing a financial burden on the aviation industry. ICAO subsequently decided that the baseline for calculating offsetting obligations for the period 2024 – 2035 would be 85% of 2019 emissions

Implementing CORSIA in Canada

Transport Canada began developing Canadian CORSIA regulations in the fall of 2017, based on the requirements from ICAO. The regulations for monitoring, reporting and verification came into effect on January 1, 2019 and the regulations for the offsetting elements of CORSIA came into effect on January 1, 2021.

In Canada, emissions on routes are aggregated and reported on a country-pair (for example, Canada – USA or Mexico – Canada) basis. This reporting method was chosen because it gathers enough information to manage CORSIA, while also reducing overall administrative burden.

All operators with international operations began monitoring, verifying and reporting their covered carbon dioxide emissions in 2019, and will do so every year.

The baseline information that is collected will be used to set the offsetting requirements for 2021 and beyond.

Who this applies to

CORSIA will affect air operators and private operators with international flights (flights between Canada and another country) that result in 10,000+ tonnes of carbon dioxide emissions, or roughly the equivalent of 3,160 tonnes of consumed fuel, each year.

Canadian CORSIA Operators

CORSIA applies to 15 Canadian operators.

  • Air Canada
  • Air Canada Rouge
  • Air Transat
  • AirSprint
  • Cargojet Airways Ltd.
  • Execaire, a division of IMP Group Ltd.
  • Flair Airlines
  • Jazz Aviation LP
  • Nolinor Aviation
  • Porter Airlines
  • Skyservice Business Aviation Inc.
  • Sunwing Airlines Inc.
  • Swoop Inc.
  • WestJet Airlines Ltd.
  • WestJet Encore Ltd.


Flights within Canada

CORSIA does not apply to flights within Canada, flights using aircraft with less than 5,700 kg maximum take-off weight, and flights for humanitarian, medical, or firefighting reasons.

New operators

New operators don’t need to offset emissions during their first 3 years in operation. However, once they pass 10,000 tonnes of CO2 emissions on international flights, they must begin the monitoring, reporting, and verification process.

Monitoring, reporting and verification (MRV)

Monitoring process

The monitoring process begins with an operator developing their emissions monitoring plan, which will be approved by Transport Canada. Each covered operator must submit a plan for each certificate they hold (PORD or AOC) with activity above the threshold. The plan is created as proof that the operator has a system in place to monitor their emissions.

Operators with less than 50,000 tonnes of covered emissions on routes subject to offsetting can also use the ICAO’s CO2 Estimation and Reporting Tool (CERT) to estimate their emissions.

See the CORSIA emissions monitoring plan and emissions reporting templates.

Reporting and verification process

Once an emissions report is prepared, the operator must hire a third-party to check their reports before submitting them to Transport Canada. This third-party must be accredited to the requirements of CORSIA by a national accreditation body. In Canada, accreditation is provided by the Standards Council of Canada. However, third-parties can be accredited in any country with a national accreditation body which is a member of the International Accreditation Forum and is working in accordance with ISO 17011.

See the list of accredited verification bodies.

Important dates

April 30, 2024 – Deadline for submitting 2023 emissions reports and 2023 verification reports

Related links