The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is a flagship regulation of the International Civil Aviation Organisation (ICAO) to limit the growth in emissions from flights between different countries, which came into effect in 2021.

NewClimate Institute, along with partners Öko-Institute and the Stockholm Environment Institute, supported the German Emission Trading Authority (DEHSt) with its contributions to the design of CORSIA. The project covered an assessment of the environmental integrity of the scheme – through assessing and proposing recommendations related to issues such as additionality, baselines, double-counting, net harm and non-permanence of emission reductions – and evaluated potential sources of supply for offset credits from various offset programmes as well as from emission trading schemes.

NewClimate led the work on the quantification of the supply potential for carbon offset credits from the Clean Development Mechanism, Gold Standard, Verified Carbon Standard and Climate Action Reserve over the period to 2035. This analysis was used to inform negotiations for the design of Emissions Unit Criteria which determine the eligibility of credits for use by aeroplane operators under CORSIA. The work provides key insights to inform relevant decision makers on the climate implications of different policy options.