CORSIA: Carbon Offsetting for Aviation

I. Definition

CORSIA stands for Carbon Offsetting and Reduction Scheme for International Aviation.
It is a global system created to limit the growth of CO₂ emissions from international aviation.

In simple terms, CORSIA requires airlines to measure, report, and offset the emissions from their international flights.
If aviation emissions increase beyond a defined level, airlines must buy carbon credits to compensate for this growth.
The objective is clear: ensure that international aviation emissions do not increase without control.

II. Context

International aviation emissions are not covered by national climate targets. Aircraft fly between countries, which makes regulation complex.
To address this, CORSIA was developed by the ICAO (International Civil Aviation Organization) as a global solution.

Under CORSIA, airlines must first monitor and report their fuel use and related emissions. This data is verified by third parties to ensure accuracy.
Only emissions above a defined baseline must be offset, meaning airlines pay only for the growth in emissions, not historical levels.

Offsets used in CORSIA must come from approved carbon credit programs. These credits must represent real, additional, and verified emission reductions.
This makes data quality, verification, and transparency central to the system.

III. Why it matters

At Orizscore, we see CORSIA as a clear example of why proof is more important than promises.
Offsetting only works if emissions are measured correctly and credits are credible.

The real challenge is not buying credits. The real challenge is proving that:

• emissions data is accurate,
• offsets are valid,
• and reductions are real.

Without reliable data and traceability, offsetting loses meaning and trust disappears.
CORSIA raises a fundamental question: can the aviation sector demonstrate transparency at a global scale?
For companies, the ability to document and explain ESG data is now a condition for legitimacy.

IV. Related terms

• Carbon Credits
  https://www.orizscore.com/blogs/carbon-credits
• Scope 1 Emissions
  https://www.orizscore.com/blogs/scope-1-emissions
• GHG Protocol
  https://www.orizscore.com/blogs/ghg-protocol

V. Example

An airline operates international flights between Europe and Asia.
Each year, it calculates fuel consumption and related CO₂ emissions for these flights.

Under CORSIA, the airline reports this data and gets it verified.

If its emissions increase compared to the baseline, it must buy approved carbon credits to offset the difference.

If the airline improves fuel efficiency or uses cleaner fuels, emissions growth is lower.
Less growth means fewer offsets to buy.
Accurate measurement and solid proof directly reduce compliance costs and reputational risk.

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