Recent meetings organized under the International Civil Aviation Organization (ICAO), a UN specialized agency established in 1944 to manage the administration and governance of the Convention on International Civil Aviation (Chicago Convention), addressed steps by ICAO to address the aviation industry’s negative environmental externalities.

At the ICAO Council meeting, which convened from 2-20 March 2020, in Montréal, Canada, the Council adopted a standard to reduce civil aviation impacts on local air quality and human health, and took further decisions on implementing the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA). CORSIA is a market-based mechanism adopted in 2016 to achieve ICAO’s goals of increasing fuel efficiency by 2% per year and carbon-neutral growth of civil aviation from 2020 onwards. The mechanism aims to cap aviation’s future emissions growth by obliging airlines to buy offsets, rather than reducing their aircraft emissions.

The ICAO Council also decided on the carbon-offsetting programmes and emissions units eligible for CORSIA’s 2021-2023 pilot phase. These six programmes are:

• American Carbon Registry
• China Greenhouse Gas (GHG) Voluntary Emission Reduction Program
• Clean Development Mechanism (CDM)
• Climate Action Reserve
• The Gold Standard
• Verified Carbon Standard

The Council’s decision follows recommendations by the Technical Advisory Body (TAB), which it established and tasked with evaluating whether carbon-offsetting programs satisfy the eight CORSIA Emissions Unit Eligibility Criteria (EUCs). Public comments were also received, including from experts at Europe-based research institutes Öko-Institut, Perspectives, and Stockholm Environment Institute (SEI), who published their analysis of 14 carbon-offsetting programs in October 2019.

In accordance with TAB’s recommendations on “eligibility timeframe” and “unit date eligibility,” the emissions units are issued to activities that commenced as of 1 January 2016, and in respect of emissions reductions occurring through 31 December 2020, subject to each programme’s scope of eligibility. The list of eligible emissions units will eventually be publicly available on the ICAO CORSIA website.

In its assessment and recommendation of programmes, TAB highlighted the following criteria:

• Permanence: Carbon offset credits must represent emissions reductions, avoidance, or carbon sequestration that are permanent, whereby any given risk of reductions or removals being reversed require that either such credits are not eligible or measures are in place to monitor, mitigate, and compensate incidences of material leakage.
• Additionality: Carbon offset programmes must generate units that represent emissions reductions, avoidance, or removals that are additional, including that they exceed any GHG reduction or removals required by law, regulation, or legally binding mandate.
• Avoidance of double counting towards mitigation obligations: Measures must be in place to avoid double issuance, double use, and double claiming such as could occur by claims from both an airline and the host country of the emissions reduction activity.
• Monitoring, reporting and verification: Emissions reduction is calculated in a conservative and transparent manner, verified by an accredited independent entity prior to issuance of offset credits, which should be based on accurate measurements and monitored on a regular basis.
• Public disclosure of sustainable development: A programme should list the criteria used regarding alignment with the SDGs.

The selected programmes performed differently, and none perfectly against all EUCs, the TAB recommendations and expert submissions reveal. TAB underscores that various programmes “made substantial progress” towards addressing certain shortcomings, or have “indicated willingness to put in place measures to ensure consistency with the EUCs.” Still, experts proposed that programmes be approved only provisionally until they satisfy all EUCs, to avoid risks for CORSIA’s integrity. Experts also called on ICAO to provide further clarity on which global warming potential values the programmes should use when issuing CORSIA eligible offset credits.

The January 2020 report from TAB recommends that the Council request from most of the eligible carbon-offsetting programs further specified actions following its decision, with the exception of the CDM. This is because the future of registered CDM activities is still being negotiated in the context of the rules, modalities, procedures, and guidelines for Article 6 (cooperative approaches) of the Paris Agreement on climate change. International guidance on the transition of the CDM is needed since all participating Paris Agreement parties will have to correspondingly adjust their emission levels and targets upon transfer of mitigation outcomes to avoid double counting.

On using carbon offset credits under CORSIA, experts hope that Paris Agreement parties will provide clarity on:

• How emission reductions not covered by Parties’ nationally determined contributions (NDCs) should be treated;
• What key elements are necessary for letters of attestation and authorization by host countries to confirm avoidance of double counting so the units can be used under CORSIA;
• How additionality of activities can be proven; and
• What actions should trigger corresponding adjustments to account for the use of offset credits under CORSIA.

The ICAO Council also improved its environmental standards to reduce civil aviation impacts on local air quality and human health. Environmental and health impact assessments of aircraft engine emissions rely on Particulate Matter (PM) characteristics such as number, size, and composition, but reported PM emissions data varied due to different sampling protocols and methodologies used. For emission certification purposes, measurement methodologies needed to be standardized. Engine manufacturers use certification of aircraft engines for non-volatile PM (nvPM) emissions.

At its March 2020 meeting, the ICAO Council adopted a “non-volatile PM (nvPM) mass and number Standard” for aircraft engines. The standard applies to engine designs of rated thrust greater than 26.7 Kilonewton and will govern both new and in-production engines from 2023 onwards. ICAO aims to ensure that only the most effective nvPM reduction technologies are employed in post-2023 aircraft engine designs.