At the 39th Assembly of the International Civil Aviation Organization (ICAO), Parties have settled an agreement to establish a global market-based measure (GMBM) in order to offset CO2 emissions from the international aviation sector.
According to ICAO, the GMBM will start from 2021 on with a pilot phase until 2023. In the following, there will be a voluntary first phase until 2026. From 2027 on, the measure will be mandatory for all States, with some examptions, such as for least developed countries, small island developing states, landlocked developing countries and states with very low levels of international aviation activity.
The GMBM foresees that greenhouse gas emissions from international aviation will not be avoided directly but they will be offset, as for example through reforestation activities. According to the Guardian, this decision has raised some criticism as it does not set an actual cap on emissions. Moreover, so far no concrete rules for offsetting have been agreed. However, the ICAO agreement includes a review period every three years that might help strengthen the efforts. In addition, the GMBM complements further actions targeted to improve the technical performance of airplanes and to advance sustainable alternative fuels for aviation.