Aviation is one of the most challenging sectors to decarbonise. Although the Paris Agreement in principle covers emissions from all sectors, including those of aviation, most Parties to the Paris Agreement have not included emissions from international flights in their Nationally Determined Contributions (NDCs). However, these emissions are explicitly addressed by the International Civil Aviation Organization (ICAO).
In 2016, ICAO adopted a market-based mechanism – the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) – to address the sector’s growth in emissions. In the meantime, Parties to the Paris Agreement in 2021 agreed on a detailed rulebook for market mechanisms under Article 6 of the Agreement, which creates linkages with CORSIA.
We identify four types of interactions between CORSIA and Article 6 rules: (1) allowing Parties with single-year targets to use the averaging accounting approach creates a loophole that may undermine the environmental integrity of both CORSIA and Article 6; (2) the quality criteria for CORSIA offsets may be strengthened by following Article 6 rules; (3) the level of CORSIA’s ambition will affect the supply side of carbon credits, including those provided under Article 6; and (4) like CORSIA, the operation of Article 6 may rely on private certification standards’ registries.
To ensure that CORSIA provides a meaningful contribution to climate change mitigation in the sector, we suggest that ICAO Member States should: (1) adopt a long-term climate target for the sector in line with the Paris Agreement, (2) revise its quality criteria for offset programmes, (3) address non-CO2 effects, and (4) carry out an assessment of the impacts on the functioning of the Article 6 mechanisms each time a decision is made.
Parties to the UN Framework Convention on Climate Change could also take specific action, including refining guidance on averaging, establishing a buffer pool to offset an increase in emissions, and considering a requirement for Parties to transition towards multi-year emission targets.
The five-yearly Global Stocktake (GST) plays an essential role in the overall ambition mechanism of the Paris Agreement on climate change by ‘assess[ing] the collective progress towards achieving the purpose of this Agreement and its long-term goals’. With the first GST due to start at COP26 in Glasgow, there is an urgent need to identify how the GST could be organised so as to maximise the effectiveness of the process. This policy brief aims to contribute to this understanding.