ICAO CORSIA

ICAO CORSIA
Name	Carbon Offsetting and Reduction Scheme for International Aviation
Established	2016
Administered by	International Civil Aviation Organization
Scope	International aviation CO2 emissions
Mechanism	Market-based measure, offsetting, carbon credits
Website	International Civil Aviation Organization

ICAO CORSIA

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is a global market-based measure developed under the aegis of the International Civil Aviation Organization to address CO2 emissions from international aviation, negotiated through sessions of the ICAO Assembly and the ICAO Council. CORSIA was adopted at the 39th Session of the ICAO Assembly in 2016 as part of wider climate diplomacy efforts that included interactions with the United Nations Framework Convention on Climate Change and commitments made at the Paris Agreement talks. The scheme links aviation policy to international carbon markets and technological pathways explored by entities such as the Airbus Group, Boeing, and the Air Transport Action Group.

Background and objectives

CORSIA was developed against the backdrop of rising emissions from carriers represented in bodies like the International Air Transport Association and passenger growth highlighted in reports from the International Energy Agency and Intergovernmental Panel on Climate Change. Its primary objective was to achieve carbon-neutral growth from 2020 onward for international aviation by requiring offsetting of emissions above a calculated baseline, a goal that intersects with commitments by states under the Paris Agreement and the sustainable fuel strategies promoted by the Roundtable on Sustainable Biomaterials. The initiative reflects precedents in market measures such as the European Union Emissions Trading System and links to voluntary mechanisms encountered in the Clean Development Mechanism and Verified Carbon Standard arenas.

Design and mechanisms

CORSIA’s design centers on baseline emissions accounting, offsetting obligations, and a phased participation model negotiated among states including United States, People's Republic of China, Russian Federation, European Union, and India. The scheme specifies emissions measurement using methodologies comparable to those used by the International Civil Aviation Organization Committee on Aviation Environmental Protection and inventory guidance from the Intergovernmental Panel on Climate Change. Offsetting relies on internationally tradable units issued by standards such as the Gold Standard, Climate Action Reserve, and Verified Carbon Standard (now Verra). Complementary measures include encouragement of sustainable aviation fuels under frameworks like the CORSIA Sustainability Criteria and technology uptake promoted by manufacturers including Rolls-Royce Holdings and General Electric Company.

Implementation and phased rollout

CORSIA’s implementation is phased: a pilot phase (2021–2023), a voluntary first phase (2024–2026), and a mandatory expansion phase from 2027 for participating states that meet criteria established by the ICAO Assembly and ICAO Council. Participation decisions have involved national regulators such as the Federal Aviation Administration, European Commission, and civil aviation authorities of Brazil, Australia, and Japan. The scheme’s baseline calculations initially used a 2019 emissions baseline adjusted after negotiations with delegations including Canada and China, and were influenced by crisis periods such as the COVID-19 pandemic which prompted temporary suspensions and policy recalibrations.

Monitoring, reporting and verification (MRV)

MRV under CORSIA requires operators and states to follow reporting templates and verification processes coordinated by ICAO guidance materials and overseen through national aviation authorities and independent verifiers accredited under mechanisms similar to those used by the International Organization for Standardization and United Nations Office for Project Services. States submit emissions data comparable to greenhouse gas inventories prepared under the United Nations Framework Convention on Climate Change while verification draws on practices used by the Intergovernmental Panel on Climate Change and certification processes implemented by entities like DNV GL and Bureau Veritas.

Eligible emissions units and market interactions

Eligible units under CORSIA must meet criteria set by ICAO’s technical bodies and have provenance connecting them to standard-setting organizations such as the Gold Standard, Verra, Climate Action Reserve, and registries operated by institutions like the World Bank’s Pilot Auction Facility. The scheme interacts with regional markets such as the European Union Emissions Trading System and national initiatives including California Cap-and-Trade, while also raising linkages with voluntary carbon markets serviced by exchanges like AirCarbon Exchange and intermediaries such as Shell and BP. Debates around double counting drew attention to accounting rules developed in consultation with the United Nations Framework Convention on Climate Change Secretariat and the International Emissions Trading Association.

Criticisms, challenges and legal issues

CORSIA has faced criticism from environmental NGOs including Greenpeace International and Friends of the Earth for relying on offsets rather than imposing direct emissions caps, and from civil society groups referencing reports by Carbon Market Watch and the Institute for European Environmental Policy. Legal questions have arisen concerning compatibility with aviation treaties such as the Chicago Convention and trade instruments encompassed by the World Trade Organization, while sovereign decisions by states like Brazil and Russia have provoked diplomatic negotiation within the ICAO Assembly. Technical challenges include ensuring additionality and permanence in credits endorsed by bodies like Gold Standard and Verra, and reconciling revenue flows with development objectives promoted by organizations such as the World Bank.

Impact and compliance outcomes

Early assessments by research institutes such as the International Council on Clean Transportation, ICCT, and academic centers at Massachusetts Institute of Technology and Imperial College London indicate mixed outcomes: CORSIA has mobilized demand for offsets and highlighted sustainable aviation fuel pathways championed by Neste and TotalEnergies, but measured emissions reductions depend heavily on credit quality and uptake by carriers like Emirates and Lufthansa. Compliance outcomes vary across jurisdictions with reporting backed by national authorities such as the Civil Aviation Administration of China and Federal Aviation Administration, while ongoing negotiations at the ICAO Assembly and among parties to the Paris Agreement will influence CORSIA’s evolution and integration into broader climate governance.

Category:International environmental agreements