CORSIA

CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) aims to limit CO₂ emissions from international flights. Developed by ICAO, its purpose is to stabilise aviation emissions at 2020 levels by requiring airlines to offset growth-related emissions through carbon credits, supporting global climate goals and sustainable aviation practices.

CORSIA is currently voluntary for participating countries during its pilot (2021–2023) and first phase (2024–2026). From 2027 onwards, it becomes mandatory for most international flights between ICAO member states, with some exemptions for least developed countries, landlocked developing countries, and small island developing states.

Carbon credits represent one tonne of CO₂ emissions or equivalent gases. Companies buy credits to offset emissions or meet carbon compliance requirements. If a company emits less than allowed, it can sell surplus credits; if it emits more, it must buy additional credits. This system encourages emissions reductions and supports investment in green technologies. Carbon credits are key in both voluntary carbon markets and regulated schemes like the UK ETS.

To comply with CORSIA, airlines must monitor, report, and verify CO₂ emissions from international flights annually. They then purchase and cancel eligible carbon offset credits to cover any emissions above 2020 levels. Compliance also involves following ICAO’s Monitoring, Reporting and Verification (MRV) requirements and submitting data to national authorities.

CORSIA is not part of the EU Emissions Trading System (ETS), but both aim to reduce aviation emissions. CORSIA is a global scheme under ICAO for international flights, while the ETS is a regional market-based mechanism covering flights within the European Economic Area. Some flights may be subject to both.