CORSia

CORSIA stands for the Carbon Offsetting and Reduction Scheme for International Aviation. It is a global market-based measure developed by the International Civil Aviation Organization (ICAO) to address carbon dioxide emissions from international aviation.

Under CORSIA, operators of international flights monitor, report, and verify their emissions, and for emissions growth above a 2020 baseline, they offset by purchasing eligible carbon offsets and retire them. Offsets are drawn from projects that reduce or remove greenhouse gases and meet ICAO's criteria for quality and verifiability.

CORSIA is implemented in phases. It began with a voluntary pilot phase intended to test the framework, with broader participation and offsetting requirements expanding over time as states join and configurations are finalized.

Eligible emission units are defined by ICAO and may include credits from recognized programs that demonstrate real, additional, verifiable, permanent reductions and are not double-counted. The scheme requires that units be locally retired to equal the amount of offsets purchased by an operator.

Governance and participation: ICAO sets rules for MRV, eligible units, and offsetting; states participating in CORSIA are responsible for administering monitoring and reporting by airlines operating within their jurisdiction. The United Nations agency oversees schedule and compliance standards.

Impact and reception: CORSIA aims to stabilize net CO2 emissions from international aviation at 2020 levels while allowing for growth through offsetting. The approach has been criticized for reliance on offsets of varying quality and for not directly reducing the emissions from inside the aviation system; supporters argue it provides a scalable, international framework until more stringent, long-term measures are in place.