Since the adoption of the Kyoto Protocol in 1997, ICAO has been under increasing pressure to produce a plan to reduce emissions from aviation. Notably, aviation emissions were excluded from the Paris Agreement. On 6 October 2016, a deal was reached by 191 countries at the Plenary Session of the International Civil Aviation Organization’s (ICAO) 39th Assembly to manage carbon dioxide (CO2) emissions from international aviation through a new global market-based measure known as the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA). With the adoption of CORSIA, the aviation industry is signaling its intent to shoulder its responsibility for emission reductions by mitigating GHG emissions from its sector.
CORSIA, which is designed to complement the basket of mitigation measures the air transport community is already pursuing to reduce CO2 emissions from international aviation (including technical and operational improvements and advances in the production and use of sustainable alternative fuels for aviation), will commence with a pilot phase from 2021 through 2023. Starting from 2021, airlines that opt in to the scheme will have to purchase offsets to balance their emissions growth above 2020 levels. More than 65 countries representing over 85% of global air traffic have said they will participate from the beginning. The pilot phase will be followed by a first phase from 2024 through 2026. Participation in both of the pilot and first phases will be voluntary and the next phase from 2027 to 2035 would see all states on board. Some exemptions were accepted for Least Developed Countries (LDCs), Small Island Developing States (SIDS), Landlocked Developing Countries (LLDCs) and States with very low levels of international aviation activity. The scheme will be reviewed every three years.
In 2010, the aviation industry had agreed on an aspirational goal to cap its emissions after 2020, so that future growth would be carbon neutral. IATA reported that aviation in 2015 emitted 781 million tonnes of CO2, meaning that if it was a country, it would be the world’s sixth largest emitter. Since the industry is expected to grow at an average rate of around 5% per year over the next two decades, it will need to find ways to significantly increase its efficiency or balance its own emissions through emissions reductions in other sectors.