An introduction to CORSIA, ICAO’s global carbon offsetting scheme for international aviation, including applicability, reporting requirements, and why it matters for aircraft operators.
By Emissence
The aviation industry is under increasing pressure to reduce its climate impact. While regional schemes such as the European Union Emissions Trading System (EU ETS) address emissions within Europe, international aviation requires a global approach. This led to the development of the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), the world’s first global market-based measure for an industrial sector.
For aircraft operators conducting international flights, understanding CORSIA is essential for maintaining regulatory compliance and preparing for future sustainability requirements.
CORSIA stands for the Carbon Offsetting and Reduction Scheme for International Aviation. It was adopted by the International Civil Aviation Organization (ICAO) in 2016 as part of a global strategy to address CO₂ emissions from international aviation.
The objective of CORSIA is to stabilize net CO₂ emissions from international aviation by requiring aircraft operators to offset emissions growth through the purchase and cancellation of eligible emissions units.
Unlike regional carbon markets such as the EU ETS, CORSIA applies at a global level through participating ICAO Member States.
International aviation emissions are not easily regulated under national climate policies because flights often cross multiple jurisdictions. Recognizing this challenge, ICAO developed CORSIA to establish a harmonized framework for monitoring, reporting, and offsetting emissions from international flights.
CORSIA complements other industry initiatives aimed at improving fuel efficiency, increasing the use of sustainable aviation fuels, and supporting the transition to lower-carbon aviation technologies.
CORSIA operates through three main components:
Aircraft operators must monitor fuel consumption and calculate CO₂ emissions from applicable international flights.
Operators submit Annual Emissions Reports that must be independently verified by an accredited verifier before submission to the relevant authority.
Where offsetting requirements apply, operators must purchase and cancel eligible emissions units to compensate for a portion of their emissions.
This process ensures that growth in international aviation emissions is balanced through emissions reductions achieved elsewhere.
CORSIA applies only to international flights between participating ICAO Member States. Domestic flights are not covered.
Examples of potentially applicable routes include:
Whether a specific route is covered depends on the participation status of both States involved.
An aircraft operator is generally subject to CORSIA if it performs international flights and exceeds the applicability thresholds established by ICAO.
Certain operators and activities remain exempt, including:
Operators meeting the applicability criteria must establish monitoring procedures and maintain compliance with reporting obligations.
For many aircraft operators, CORSIA represents the first global climate compliance programme affecting international operations.
Although the administrative requirements may appear straightforward, compliance often requires:
As sustainability reporting becomes increasingly important for airlines, investors, regulators, and customers, CORSIA compliance has become an important component of corporate environmental strategy.
CORSIA continues to evolve as ICAO refines implementation requirements and participating States expand their involvement.
In our next article, we will examine CORSIA applicability in detail, including operator thresholds, participating States, exemptions, and common compliance challenges faced by aircraft operators.
Emissence supports aircraft operators with CORSIA Monitoring Plans, emissions reporting, verification readiness, data management, and ongoing compliance support.
Whether you are preparing for your first reporting cycle or looking to strengthen your existing compliance programme, our specialists can help simplify the process and reduce compliance risks.
Contact us at [connect@emissence.com](mailto:connect@emissence.com) to discuss your CORSIA compliance requirements.
ICAO has published an updated overview of CORSIA Eligible Emissions Units (CEEUs), providing transparency on approved carbon credit programmes and the emissions units available for use during the 2024–2026 CORSIA First Phase.
Learn how CORSIA applicability is determined, including operator thresholds, route coverage, aircraft exemptions, participating States, and common compliance challenges.
Understand the practical aspects of CORSIA compliance, including emissions monitoring, annual reporting, independent verification, CORSIA Eligible Fuels, and offsetting requirements.
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