Policy Update | ICAO | Aviation Decarbonization Published: June 5, 2026 | Last Updated: June 2026 | Sources: ICAO, ITF, Aviation Pros, GreenAir News
Quick Summary
ICAO held its Aviation Climate Week in Montreal from June 2 to 4, 2026. The theme was “One Global Path: Advancing Net-Zero Aviation.”
The event launched a new program called ACT-LTAG. It will help countries and airlines prepare for the global net-zero aviation goal by 2050.
CORSIA Phase 2 becomes mandatory on January 1, 2027. That gives airlines and governments just six months to get ready. This event was a key checkpoint in that preparation.
Quick Facts
| Item | Details |
|---|---|
| Authority | ICAO |
| Event | ICAO Aviation Climate Week 2026 |
| Theme | One Global Path: Advancing Net-Zero Aviation |
| Dates | June 2–4, 2026 |
| Location | ICAO Headquarters, Montréal, Canada |
| Key Launch | ACT-LTAG Programme |
| Methodology Advanced | ICAO LTAG Monitoring and Reporting (LMR) |
| Milestone Recognised | CORSIA — 10 years of implementation |
| CORSIA Phase 2 Start | January 1, 2027 — mandatory |
| Joint Announcement | IATA-ICAO SAF Tracking Cooperation — June 2, 2026 |
| Applies To | All ICAO member states, airlines, SAF producers |
What the Event Produced
1. Launch of ACT-LTAG
ACT-LTAG stands for Assistance, Capacity-building and Training for the Long-Term Global Aspirational Goal.
Think of it as ICAO’s support program for countries that need help meeting the net-zero target by 2050.
Previously, ICAO had a similar program called ACT-SAF. That one focused only on sustainable aviation fuel. ACT-LTAG covers everything — SAF, emissions monitoring, CORSIA compliance, and the full decarbonization agenda.
What ACT-LTAG provides:
- Policy and regulatory guidance for CORSIA Phase 2 implementation
- Technical assistance for national aviation authorities
- Training for compliance teams in developing aviation markets
- Support for building verification and accreditation systems
The program is especially useful for smaller aviation markets. These countries often lack the technical resources to implement complex ICAO requirements on their own.
2. CORSIA Monitoring and Reporting Update
ICAO also updated its LTAG Monitoring and Reporting (LMR) methodology.
This methodology is not a minor technical document. It defines how CO₂ emissions reductions are measured and reported under CORSIA.
It answers questions like:
- How do airlines calculate their emissions reductions from SAF?
- What data must be collected for Phase 2 compliance?
- How are individual airline reports combined into state-level CORSIA submissions?
Airlines whose reporting systems do not match the LMR methodology will face compliance gaps from day one of Phase 2. The June 2026 update gives airlines approximately six months to align their systems.
3. Ten Years of CORSIA
The event also marked a decade since CORSIA was adopted.
Speakers reviewed Phase 1 performance across monitoring, reporting, and verification. They noted that while Phase 1 demonstrated that CORSIA is operationally feasible, Phase 2 is a fundamentally different challenge.
Phase 2 covers virtually all international aviation routes. It includes countries that sat out Phase 1 — China, India, Brazil, and Russia among them. The volume of covered emissions nearly doubles.
4. IATA-ICAO SAF Tracking Agreement
On June 2 — the first day of Climate Week — ICAO and IATA announced formal cooperation on SAF tracking and data integrity.
Both organizations agreed to explore how SAF registries can support the LMR methodology. They also agreed to work on fuel accounting systems for international aviation.
ICAO Secretary General Juan Carlos Salazar said the agreement would strengthen ICAO’s leadership in supporting states and industry in scaling up SAF.
IATA Director General Willie Walsh said that credible tracking of SAF use is necessary to build trust and put aviation on track to reach net zero by 2050.
Why This Matters
CORSIA Phase 2 starts in six months. Airlines operating international routes — including routes newly covered by Phase 2 — face mandatory offsetting from January 1, 2027. There is no grace period.
The LMR methodology determines your offsetting bill. If your reporting system does not capture the right data inputs, your offsetting obligation may be calculated incorrectly. Either you pay more than necessary, or you fall short of compliance.
SAF accounting under CORSIA differs from that under ReFuelEU. The IATA-ICAO cooperation is partly aimed at clarifying this. SAF used under the UK or EU mandate may not automatically generate CORSIA credit. Double-counting rules apply. Airlines must check before assuming credit.
Developing-nation carriers now have formal support. The ACT-LTAG programme provides direct technical assistance. Airlines registered in states without robust CORSIA infrastructure should engage with this program now.
Who Is Affected
All Airlines on International Routes: CORSIA Phase 2 is mandatory for virtually all ICAO member states from January 1, 2027. Any airline operating international flights between participating states faces offsetting obligations.
National Aviation Authorities States must implement LMR-compliant reporting and verification systems before January 2027. ACT-LTAG provides direct support for this work.
SAF Producers and Certifiers: The IATA-ICAO framework clarifies how SAF registries interact with CORSIA eligibility criteria. This affects how producers’ fuel is valued for compliance purposes.
Compliance and Sustainability Teams: The LMR methodology update defines exactly what data must be collected and how it must be reported. Compliance teams should review their current systems against the updated methodology immediately.
Implementation Timeline
| Milestone | Date |
|---|---|
| ICAO 42nd Assembly — LTAG net-zero 2050 adopted | 2022 |
| ACT-SAF Programme launched | 2023 |
| CORSIA Phase 1 begins | January 1, 2024 |
| ICAO Aviation Climate Week — ACT-LTAG launched | June 2–4, 2026 |
| IATA-ICAO SAF tracking cooperation announced | June 2, 2026 |
| IATA 82nd AGM — SAF and CORSIA on agenda | June 6–8, 2026 |
| EU Commission CORSIA adequacy assessment | By July 2026 |
| CORSIA Phase 2 — mandatory | January 1, 2027 |
| Phase 2 Year 1 notification to airlines | By November 30, 2028 |
| Phase 2 first CEEU cancellation deadline | By January 31, 2029 |
Operational Impact
Check Your Reporting Systems Now: Airlines should audit their CO₂ monitoring systems against the updated LMR methodology. Any gaps — especially for newly covered Phase 2 routes — must be closed before January 1, 2027.
Review Your SAF Procurement Plans: The IATA-ICAO cooperation will clarify whether SAF uplifted under ReFuelEU or the UK SAF Mandate generates CORSIA credits. Wait for those outputs before finalizing 2027 SAF procurement strategies.
Start Buying Carbon Credits Early: Phase 2 offsetting costs are projected to be 30% higher than Phase 1. Airlines that wait for formal Phase 2 notifications in late 2028 will face a seller’s market. The time to build CEEU relationships is now.
Engage ACT-LTAG if Your State Needs Support: Airlines in developing aviation markets should contact ICAO about ACT-LTAG access. The program is designed specifically to reduce the complexity of Phase 2 compliance for smaller markets.
Industry Response
ICAO Secretary General Juan Carlos Salazar said the IATA cooperation agreement “will support the strengthening of ICAO’s leadership as we support States and industry in their scaling up of sustainable aviation fuels.”
IATA’s Willie Walsh said credible SAF tracking “is necessary to know the emissions reductions delivered by SAF” and to put aviation on the path to net zero by 2050.
Climate policy groups monitoring the event called the LMR methodology discussions critical. How SAF emissions reductions are treated in the methodology will determine whether CORSIA is judged adequate under Paris Agreement standards.
Official Sources
- ICAO Aviation Climate Week 2026 — Outcomes and Program
- ICAO-IATA SAF Cooperation Announcement, June 2, 2026
- ICAO — ACT-LTAG Program
- ITF — ICAO Aviation Climate Week 2026 Overview
Action Steps
Airlines, national aviation authorities, and SAF stakeholders should:
- Audit CORSIA Phase 2 route coverage now — identify newly covered routes and confirm emissions monitoring systems are in place
- Review the updated LMR methodology and check whether current reporting systems capture the required data inputs
- Engage ACT-LTAG if your state of registry is a developing aviation market
- Monitor IATA-ICAO SAF tracking outputs before finalizing 2027 SAF procurement plans
- Begin CEEU procurement planning now — credit supply will tighten as Phase 2 approaches
- Schedule a Phase 2 readiness review before Q3 2026
Frequently Asked Questions
What is ACT-LTAG?
It is ICAO’s program to help countries and airlines implement the net-zero by 2050 aviation goal. It provides technical assistance, training, and regulatory guidance. It extends the earlier ACT-SAF program to cover the full decarbonization agenda.
What is the LTAG Monitoring and Reporting methodology?
It is ICAO’s framework for measuring CO₂ emissions reductions from aviation. It defines what airlines must report and how reductions from SAF and operations are credited under CORSIA Phase 2.
When does CORSIA Phase 2 start?
January 1, 2027. It is mandatory for virtually all ICAO member states. It covers routes not included in Phase 1, including those involving China, India, Brazil, and Russia.
How does the IATA-ICAO SAF cooperation affect airlines?
It will clarify how SAF use is tracked, verified, and credited under CORSIA. It will also address whether SAF uplifted under national mandates — like ReFuelEU or the UK SAF Mandate — can generate CORSIA credit without double-counting.
What is CORSIA’s role in reaching net-zero aviation?
CORSIA addresses the growth in emissions above the 2019 baseline through offsetting and the use of SAFs. It is the international mechanism for managing aviation emissions while longer-term technology and fuel solutions scale up.
Related Updates
- CORSIA Phase 2 from 2027: What US Airlines Need to Prepare
- FAA SAF Grand Challenge: Progress Toward 3 Billion Gallons by 2030
- EU ETS Aviation Free Allowance Phase-Out — Full Enforcement Active from 2026
Editorial Note: This article is based on official ICAO publications, ITF event summaries, and GreenAir News coverage of the ICAO Aviation Climate Week 2026 held June 2–4 in Montréal. The ACT-LTAG program details and LMR methodology status should be verified against current ICAO documentation at icao.int before compliance planning decisions are made. Researched and reviewed using official ICAO, ITF, and aviation industry sources.