In the General Assembly of the International Civil Aviation Organization (ICAO) in 2016, the member states made the decision to implement the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA). The decision made aviation the first field with a global market-based emissions reduction system.
Carbon-neutral growth as the goal
Air traffic causes over 2% of the carbon dioxide emissions in the world. In addition to carbon dioxide, aviation generates other emissions, such as oxides of nitrogen (NOx), soot particles, oxidised sulphur species, and effects from water vapour, including contrails, some of which have a warming effect on the climate and some of which have a cooling effect. Aviation accounts for about 3.5% of human-caused global warming, approximately 66% of which is currently attributed, with considerable uncertainty, to non-CO2 emissions. Due to the predicted growth of air traffic, the emissions will multiply unless more effective measures are taken to reduce them.
The aim of CORSIA is to ensure the carbon-neutral growth of international aviation. According to the goals of ICAO, the primary methods of achieving emission reductions are aircraft technology, sustainable alternative fuels as well as energy-efficient aviation and use of airspace. However, these measures will not be enough for the near future, and therefore a market-based compensation system is required.
The growth of emissions is offset by purchasing Emission Units and Sustainable Aviation Fuels
In CORSIA, aircraft operators offset the growth of emissions in international air traffic by purchasing CORSIA’s approved emission units, mainly originating from emission reduction projects in other fields, on the carbon market. The compensation obligation is calculated annually by comparing the emissions generated on the routes between CORSIA member states to the baseline, which is 85% of 2019 emissions during 2024 – 2035 and by reducing the potential use of CORSIA-eligible fuels.. Further information on the obligations of aircraft operators can be found on the page on the monitoring, reporting and verification of emissions (External link) and and in Commission Delegated Regulation (EU) 2019/1603 (External link).
Participating states
ICAO maintains a list (External link) of the states that have volunteered to participate in CORSIA from the start on its CORSIA website. Finland has volunteered to join together with the 44 member states of the European Civil Aviation Conference (ECAC).
Implementation
In accordance with Commission Delegated Regulation (EU) 2019/1603, CORSIA is implemented in the European Union on the basis of the Emissions Trading Directive (2003/87/EC) and implemented in Finland through the Emissions Trading Act (1270/2023) (External link) . The Finnish Transport and Communications Agency Traficom is responsible for implementing CORSIA in Finland.
Currently, the aim is to reduce emissions from internal flights in the European Economic Area also with the help of the EU emissions trading system for aviation (External link).