Why Choose Arthian's Carbon Consultants?
Engineering services delivered by specialists:
Airport Carbon Accreditation (ACA)
Airport Carbon Accreditation, Verified at the Highest Level — Arthian is home to one of the UK’s only Level 5 ACA Verifiers
Airport Carbon Accreditation (ACA) is the global benchmark for airport carbon management, recognised by ICAO, UNFCCC and the European Commission. It provides a structured, independently verified pathway for airports to measure, reduce and ultimately transform their carbon performance in line with international net‑zero expectations.
ACA is built on robust carbon accounting, transparent reporting and evidence‑based decarbonisation. Each level requires airports to demonstrate increasing maturity in emissions management, stakeholder engagement and long‑term climate strategy.
This is where Arthian stands apart.
Arthian is one of the only organisations in the UK with a Level 5 ACA Verifier — one of just two nationally. This places us in an elite tier trusted to verify the most advanced airport decarbonisation claims, including:
- full‑scope carbon inventories
- validated long‑term reduction pathways
- alignment with global net‑zero frameworks
- credible residual emissions and neutralisation strategies
Having Level 5 verification capability in‑house means airports benefit from top‑tier assurance, faster verification cycles, and unmatched technical clarity. It also gives your submission credibility recognised across the global airport sector.
What Are the ACA Levels?
ACA consists of six progressive levels, each representing a step change in carbon maturity. As airports advance, the requirements become more technical, more stringent, and more closely aligned with global net‑zero frameworks.
Establish a complete carbon footprint using recognised methodologies. This forms the baseline for all future ACA progression.
Demonstrate measurable emissions reductions through implemented carbon management measures and year‑on‑year performance improvements.
Expand carbon boundaries to include Scope 3 emissions, engaging airlines, tenants, ground handlers and other airport stakeholders.
Integrate carbon reduction into long‑term strategy, infrastructure planning and investment decisions. Align airport decarbonisation with science‑based pathways.
Demonstrate deep decarbonisation aligned with global net‑zero frameworks, including transparent reporting and credible residual emissions management.
The highest and most demanding level. Airports must prove:
- full‑scope carbon accounting
- validated long‑term decarbonisation pathways
- climate resilience and adaptation integration
- transparent reporting aligned with global standards
- credible residual emissions and neutralisation
Verification at Level 5 can only be carried out by a very small number of accredited experts — and Arthian has one of the UK’s only two.
This gives airports:
- unmatched technical assurance
- direct access to Level 5 expertise
- credibility recognised across the global airport sector
- smoother progression through Levels 1–4+
- confidence that their submission meets the highest international standards
Our Airport Carbon Accreditation Services
We provide end-to-end ACA support—from emissions mapping and reduction planning to stakeholder engagement, reporting, and independent verification—helping airports meet accreditation goals and demonstrate climate leadership.
Carbon Footprinting & Emissions Mapping
We deliver Scope 1, 2, and relevant Scope 3 inventories aligned with ACA, GHG Protocol, and ISO 14064, establishing a verifiable baseline for reporting and reduction planning. This supports accurate emissions tracking and progression through ACA levels.
Our support includes:
- Mapping of airport-related emissions across scopes
- Alignment with ACA, GHG Protocol, and ISO 14064 standards
- Development of baselines for reporting and reduction strategies
ACA Strategy & Roadmapping
We define tailored pathways to initial or higher-level ACA certification, aligning with your operations, stakeholder dynamics, and Net Zero goals. This ensures your airport’s carbon strategy is actionable, scalable, and recognised by global standards.
Our support includes:
- Development of ACA-aligned carbon management strategies
- Roadmaps for progressing through ACA levels
- Integration with operational plans and Net Zero targets
Stakeholder Engagement & Scope 3 Integration
We facilitate collaboration with airlines, ground handlers, and concessionaires to quantify and reduce Scope 3 emissions, essential for achieving ACA Levels 3 and above. This ensures a coordinated approach to airport-wide carbon management.
Our support includes:
- Stakeholder engagement planning and facilitation
- Scope 3 emissions data collection and validation
- Joint action planning for reduction across the airport ecosystem
Emissions Reduction Planning
We identify high-impact carbon reduction opportunities across energy, fleets, renewables, and operations, aligned with ACA targets and airport-specific constraints. This supports meaningful progress toward certification and long-term Net Zero goals.
Our support includes:
- Assessment of energy systems and operational efficiency
- Identification of fleet and renewable energy opportunities
- Development of targeted reduction actions aligned with ACA levels
Reporting, Assurance & Submission Support
We manage ACA submissions from start to finish, ensuring compliance with ACI standards and alignment with SECR, CDP, and TCFD frameworks. This streamlines your reporting process and strengthens the credibility of your carbon disclosures.
Our support includes:
- Preparation and review of ACA documentation and evidence
- Coordination of assurance activities and verification processes
- Submission management aligned with ACI and ESG frameworks
Pre-Application Review
We assess readiness, review documentation, and recommend actions to strengthen your ACA application and avoid delays. This ensures your submission is complete, compliant, and positioned for successful accreditation.
Our support includes:
- Review of baseline data, methodologies, and evidence
- Gap analysis against ACA requirements
- Action planning to address issues before formal submission
Independent Verification
Our qualified ACA Verifiers deliver third-party assurance across Levels 1–5, ensuring credibility and compliance with ISO 14064-3. This supports transparent reporting and strengthens your airport’s carbon management credentials.
Our support includes:
- Independent verification of ACA submissions and data
- Compliance checks against ISO 14064-3 requirements
- Issuance of assurance statements for ACA accreditation
Integration
Fully integrated with geotechnical, hydrological, and ecological disciplines.
Our Experience
National experience with regional insight and regulatory familiarity.
Our Understanding
Deep understanding of planning, infrastructure, and environmental interfaces.
Results Driven
Commitment to technical rigour, clear communication, and long-term outcomes.
Frequently Asked Questions
Can Arthian support airports at all ACA levels?
Yes. Arthian provides full‑journey support from Level 1 through Level 5, including carbon mapping, reduction planning, Scope 3 engagement, science‑aligned transition planning and full verification.
Why is Arthian’s Level 5 capability important?
Arthian is home to one of the UK’s only two ACA Level 5 Verifiers. This gives airports:
- top‑tier technical assurance
- faster, clearer verification cycles
- credibility recognised across the global airport sector
- confidence that Level 5 submissions meet the highest international standards
For airports aiming to lead the sector, Level 5 verification is a strategic differentiator — and Arthian is one of the very few organisations able to deliver it.
How long does ACA certification take?
BREEAM Infrastructure replaces CEEQUAL, offering improved alignment with international standards and integration with the wider BREEAM family.
Can we skip levels and apply for a higher accreditation?
Yes. If your airport meets the criteria, ACA allows direct application to higher levels. We assess your readiness and guide you through the process.
What data is required for ACA certification?
You’ll need Scope 1 and 2 emissions data, and potentially Scope 3. This includes energy use, fuel consumption, fleets, and third-party activities. We help you collect and validate it.
Is ACA aligned with Net Zero goals?
Absolutely. Levels 4, 4+, and 5 support science-based Net Zero pathways and long-term carbon strategies—making ACA a credible route to climate leadership.
Get in Touch
We’d love to hear from you – whether you have a question, a project in mind, want to explore job opportunities, or just want to say hello.