Airport carbon accreditation (ACA program) and CORSIA verification services
TÜV SÜD America supports airports and airlines in effectively measuring, managing and reducing their aviation carbon footprint. We have a deep understanding of airport and airline greenhouse gas (GHG) inventories and are well-versed in the emission sources and activity data required to comply with both the Airport Carbon Accreditation (ACA Program) and the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).
Our experience includes the verification of major international airports and airlines, with a strong focus on LTO cycle emissions and the implementation of accurate and reliable carbon calculation methodologies.
We have delivered CORSIA verification services to airlines operating in:
- United States
- Mexico
- Bolivia
- Brazil
Airport carbon accreditation (ACA program): supporting sustainable airports
Airport Carbon AccreditationThe ACA Program is the only globally recognized standard for airport carbon management and certification. It is a voluntary initiative designed to help airports reduce CO₂ emissions and implement long-term sustainability strategies.
Launched in 2009, the Airport Carbon Accreditation program has certified over 300 airports worldwide, enabling them to improve energy efficiency and stakeholder engagement through a structured approach across four certification levels:
- Level 1 – Mapping: Establishing a verified carbon footprint
- Level 2 – Reduction: Implementing a carbon management plan
- Level 3 – Optimization: Engaging third parties
- Level 4/4+ – Transformation/Neutrality: Offsetting residual emissions and achieving carbon neutrality
- Level 5 (where applicable): Net zero transition alignment
TÜV SÜD America has conducted independent third-party verifications for several major airports at Level 4, 4+ and Level 5 of the ACA Program. We ensure your airport complies with ACA requirements, whether for a first-time accreditation, level upgrade, or biennial renewal.
Through our accredited verification services, we help demonstrate that your airport is actively managing and reducing Scope 1 and Scope 2 carbon emissions, aligned with ACA and international climate goals.
Aviation carbon and the CORSIA framework
CORSIA, developed by the International Civil Aviation Organization (ICAO), is a global market-based mechanism aimed at offsetting carbon emissions from international aviation. It addresses the aviation sector’s environmental impact by promoting emissions monitoring, reporting, and offsetting.
Key CORSIA goals include:
- Improving fuel efficiency by 1.5% per year (2009–2020)
- Stabilizing net CO₂ emissions from 2020 (carbon-neutral growth)
- Cutting net aviation CO₂ emissions by 50% by 2050 (compared to 2005 levels)
This strategy is based on four core pillars:
- Advanced technology, including sustainable fuels
- Operational improvements in aircraft performance
- Infrastructure upgrades, like optimized air traffic management
- A global market-based measure (CORSIA) to offset remaining emissions
As accredited verifiers, TÜV SÜD America helps airlines demonstrate compliance with CORSIA by validating CO₂ emissions data and offset activities. Our services support transparency and credibility in reporting, aligned with global best practices.
Why choose TÜV SÜD for airport carbon accreditation?
- Recognized expertise in aviation carbon verification
- Proven track record in the ACA Program and CORSIA
- Customized support for airports and airlines worldwide
- Independent, ISO-accredited third-party verification body
- Partner with us to strengthen your environmental commitments and improve stakeholder trust through verified climate action.
Frequently asked questions
What is the Airport Carbon Accreditation (ACA) program and how does it work?
Airport Carbon Accreditation (ACA) is an ACI‑endorsed global certification that independently assesses and recognizes airports’ efforts to measure, manage and reduce CO2 emissions through a tiered accreditation pathway. Airports enroll, compile a greenhouse gas inventory, implement emissions‑management actions and submit that work for independent verification; successful airports are awarded one of the ACA levels that reflect increasing ambition from footprint measurement to net‑zero/neutrality and transformation.
How can airports achieve Level 4 or higher ACA certification?
To attain Level 4 or Level 4+ / Level 5 an airport must go beyond measuring and managing its own (scope 1 and 2) emissions to actively reduce absolute emissions across the airport ecosystem and engage third parties. Entities must:
- Demonstrate measured and verified absolute reductions in scope 1 and 2 emissions (Transformation) and implement a clear roadmap to address scope 3 emissions and partner emissions where required.
- Show systematic engagement with airlines, ground handlers, tenants and other airport business partners to reduce shared emissions (e.g., electrification of ground operations, sustainable aviation fuel facilitation, infrastructure changes).
- Use robust third‑party verification to confirm GHG inventories, reduction claims and any compensating/removal offsets
- Ensure credible compensation/offset removals for residual emissions are used and have in place third‑party engagement and governance practices
What emission sources are included in airport GHG inventories?
Inventories typically follow scope definitions—Scope 1 (direct emissions from airport‑owned/controlled sources such as on‑site fuel combustion and airport vehicle fleet), Scope 2 (purchased electricity/heating/cooling consumed by the airport operator) and Scope 3 (indirect emissions across the value chain including third‑party ground handlers, tenant operations, airside operations not controlled by the operator, passenger/employee travel, waste, purchased goods). Airport tools and guidance (e.g., ACERT, ACRP guides) define typical source lists and calculation methods to ensure consistency.
Why is third-party verification important for ACA?
Third‑party verification provides independent assurance that inventories, monitoring systems and reported reductions or offsets are accurate, complete and compliant with program rules. Its core roles are:
- Ensuring credibility and comparability of reported emissions and reduction claims, which protects the integrity of accreditation or offsetting commitments.
- Detecting errors or omissions in data, validating the application of approved methods and confirming that offsets/claims meet program‑specific requirements
- Satisfying stakeholders (regulators, airlines, passengers, investors) that the airport’s claims are independently substantiated and not greenwash
