In December 2024, the UK Department for Transport (DfT) published a consultation on the implementation of the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) offsetting requirements in the UK. This consultation relates to the second part of CORSIA and follows the implementation of CORSIA's monitoring, reporting, and verification (MRV) requirements in 2021.
The consultation requests feedback on the proposed CORSIA offsetting provisions and the approaches proposed to the interaction between CORSIA and UK Emissions Trading Scheme (ETS) requirements. Responses to the consultation are requested by 24 February 2025, after which the DfT aims to publish responses and implement the relevant legislation as soon as parliamentary time allows.
What is CORSIA?
CORSIA is a global market-based initiative developed and regulated by the International Civil Aviation Organisation (ICAO) to address CO2 emissions from the international aviation sector by stabilising emissions growth at 85% of 2019 levels.
CORSIA's voluntary first phase is currently underway and will expire at the end of 2026, at which point the second phase will begin. The UK along with 128 other ICAO states (including all EU member states) has confirmed its participation in CORSIA's first phase. During the second phase (from 2027 to 2035), CORSIA will be mandatory for all 193 ICAO states, subject to certain exceptions. Currently a decision on whether CORSIA will extend into a third phase past 2035 has not been taken.
Aeroplane operators to which CORSIA applies must monitor, report and verify their emissions from international flights between participating states. Where monitoring shows emissions in excess of the baseline over a three-year measurement cycle, aeroplane operators must purchase eligible emissions units (EEUs) to offset the excess emissions.
The UK has already transposed the MRV requirements into national law through the Air Navigation (CORSIA) Order 2021. Now, the DfT is consulting on how best to implement the CORSIA offsetting obligations into national law, aiming to minimise the differences between UK legislation and the international standard.
Consultation on implementing CORSIA
The consultation is split into two distinct sections. The first part sets out the proposed CORSIA offsetting provisions (including applicability, calculation of offsetting requirements, cancellation of EEUs and enforcement). The second part addresses potential approaches to the interaction between CORSIA and UK ETS requirements.
Currently, the UK ETS applies to flights operated between the UK and the EEA or Switzerland and requires aircraft operators to monitor, verify and report their CO2 and other greenhouse gas emissions and surrender sufficient allowances to cover those emissions.
If CORSIA is implemented in its entirety, CO2 emissions on flights from the UK to the EEA or Switzerland will fall within the scope of both CORSIA and the UK ETS, resulting in double charging for those emissions.
The two different approaches the DfT is considering to mitigate any double counting are:
The consultation closes on 24 February 2025, and the responses received will inform a final decision on the UK's approach to implementing CORSIA and its interaction with the UK ETS.