Technical guidance on carbon credits, EU ETS, voluntary carbon markets, and blockchain carbon market innovation for Ireland and the EU.
Aviation Carbon Markets | Ireland | ICAO CORSIA
Meta Description: CORSIA aviation carbon offset scheme explained by Michael English (IMPT.io). What CORSIA means for Irish aviation — Ryanair, Aer Lingus, Dublin Airport — and compliance strategies.
Target Keywords: CORSIA aviation Ireland, aviation carbon offsets Ireland, CORSIA compliance Irish airlines, Ryanair CORSIA, aviation ETS Ireland, Michael English CORSIA aviation
Aviation contributes approximately 2.4% of global CO₂ emissions — but when non-CO₂ effects (contrails, water vapour, NOx reactions at altitude) are included, aviation's total climate impact is estimated at 3.5–5% of anthropogenic warming. International aviation's emissions fall into a policy gap: domestic flights are covered by national or EU ETS frameworks, but international flights between countries cross jurisdictions.
CORSIA — the Carbon Offsetting and Reduction Scheme for International Aviation — is the ICAO (International Civil Aviation Organization) response to this challenge. For Ireland, whose aviation sector is dominated by major international carriers, CORSIA compliance is a growing strategic concern.
CORSIA was adopted by ICAO's 191 member states in October 2016 as Resolution A39-3. It is the first global market-based measure for any industry sector, requiring airlines to offset growth in international aviation CO₂ emissions above 2019 levels.
| Phase | Period | Participation |
|---|---|---|
| Pilot phase | 2021–2023 | Voluntary (88 states volunteered) |
| First phase | 2024–2026 | Voluntary |
| Second phase | 2027–2035 | Mandatory (all ICAO states with >0.5% of global aviation activity) |
Ireland is a participant in the voluntary phases and will be subject to the mandatory phase. Both Ryanair and Aer Lingus are major international carriers with significant CORSIA obligations.
Baseline: 2019 is the established baseline year for international aviation emissions (COVID-19 years 2020-2021 were originally proposed but 2019 was retained given the pandemic distortion).
Obligation: For each year above the baseline, airlines must either:
Formula:
CORSIA obligation (tCO₂) = (Current Year Emissions - Baseline 2019 Emissions) × Sector Growth Factor
The "sector growth factor" adjusts individual airline obligations based on the sector's overall growth rate vs. individual airline growth.
Not all carbon credits qualify for CORSIA. ICAO's Technical Advisory Body (TAB) maintains a list of approved programmes whose credits are eligible as CORSIA Eligible Emissions Units (EUs):
Approved programmes (as of 2024):
Key eligibility criteria:
A critical complexity: CORSIA EUs must not create double counting with Paris Agreement NDC accounting. The corresponding adjustment requirement means:
Ryanair, headquartered in Dublin and operating under Irish Air Operator Certificate, is Europe's largest airline by passenger numbers. Ryanair's CORSIA exposure:
Ryanair has publicly committed to achieving net-zero by 2050, with Sustainable Aviation Fuel (SAF) as the primary pathway and CORSIA offsets as a transitional measure.
Aer Lingus, operating from Dublin and Cork as part of the IAG group (with British Airways and Iberia), has significant transatlantic routes subject to CORSIA. IAG has published a net-zero 2050 commitment and is among the largest buyers of SAF globally.
The DAA (Dublin Airport Authority) is responsible for airport operations but not flight emissions directly. However, DAA's airport development plans and slot allocation strategies are influenced by CORSIA and EU ETS costs as they affect airline operational economics at Dublin.
CORSIA and EU ETS aviation compliance costs are designed to accelerate the transition to Sustainable Aviation Fuel (SAF) — jet fuel produced from renewable or waste feedstocks that reduces lifecycle CO₂ vs conventional jet fuel.
| SAF Pathway | Feedstock | Lifecycle CO₂ Reduction vs Jet A-1 |
|---|---|---|
| HEFA (Hydroprocessed Esters and Fatty Acids) | Used cooking oil, tallow | 60-80% |
| AtJ (Alcohol-to-Jet) | Ethanol/sugar crops, cellulosic waste | 50-70% |
| FT (Fischer-Tropsch) | Municipal solid waste, agricultural residues | 70-90% |
| Power-to-Liquid (PtL) | Green hydrogen + captured CO₂ | 85-95%+ |
HEFA is currently the dominant commercial SAF pathway, constrained by feedstock availability. Power-to-Liquid SAF (e-kerosene) is the ultimate solution but requires massive green electricity and electrolytic hydrogen capacity.
ReFuelEU Aviation (Regulation 2023/2405), entering force from 2024, mandates minimum SAF blending at EU airports:
| Year | Minimum SAF Blend |
|---|---|
| 2025 | 2% |
| 2030 | 6% |
| 2035 | 20% |
| 2040 | 34% |
| 2050 | 70% |
The ReFuelEU regulation applies to fuel uplifted at EU airports, directly affecting Dublin Airport and Cork Airport. Aviation fuel suppliers serving Irish airports must comply with these minimums.
Irish businesses developing high-quality carbon projects have a direct CORSIA market opportunity:
Credits from Irish projects can qualify for CORSIA compliance if:
Peatland restoration: If registered under an ICAO-approved programme with appropriate methodology, Irish peatland rewetting could generate CORSIA-eligible removal credits. The permanence requirements of removal credits and CORSIA eligibility criteria need careful alignment.
Forestry (Afforestation/Reforestation): COILLTE's afforestation programme and SFI-funded private forestry could potentially generate CORSIA-eligible forestry credits, though permanence and additionality requirements are demanding.
Renewable Energy: Irish offshore wind, solar, and onshore wind projects can generate Gold Standard I-REC or ACR renewable energy credits that, under certain conditions, qualify for CORSIA.
CORSIA's enforcement mechanism is handled nationally: each state is responsible for ensuring airlines registered in their jurisdiction comply. Ireland's compliance framework:
Irish Aviation Authority (IAA) / IAASA: The Irish Aviation Authority administers CORSIA compliance for Irish-registered airlines. Airlines must submit annual emissions reports and demonstrate EU surrender.
Penalties: ICAO does not specify penalties; these are set nationally. Non-compliant airlines risk:
The mandatory phase of CORSIA (2027–2035) will dramatically expand compliance obligations:
The key uncertainty is whether international aviation emissions will have fallen sufficiently below 2019 levels by 2027 (due to SAF deployment and efficiency improvements) to reduce offsetting needs. Current trajectories suggest aviation recovery above 2019 levels by 2024-2025, creating offset obligations from the pilot phase's first year.
CORSIA represents a genuine step forward for aviation's climate accountability — the first global, sector-wide carbon market mechanism in history. For Ireland, with its outsized aviation sector and major international carriers, CORSIA is not a distant policy abstraction but a present compliance and commercial reality.
The combination of CORSIA, EU ETS aviation, and ReFuelEU SAF mandates creates a policy environment that will drive substantial changes in Irish aviation economics through the 2020s and 2030s. Airlines, airports, fuel suppliers, and carbon market participants all need to engage proactively with this evolving landscape.
The window for low-cost SAF offtake agreements and high-quality carbon credit portfolio building is open now. It will close as compliance demand intensifies.
Michael English is Co-Founder & CTO of IMPT.io, a blockchain carbon credit marketplace operating in EU and international markets. Based in Clonmel, Co. Tipperary, Ireland.
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