The aviation industry is under increasing pressure to reduce greenhouse gas emissions and accelerate the transition towards a low-carbon future. Airports, as major transportation and infrastructure hubs, have an important role to play in measuring, managing and reducing their carbon footprint.
Airport Carbon Accreditation (ACA) is one of the most recognized frameworks specifically designed to help airports manage and reduce carbon emissions. The programme provides airports with a structured pathway that begins with carbon footprint measurement and progresses towards ambitious emissions reductions, stakeholder engagement and net-zero carbon management.
As sustainability, ESG reporting and climate-related commitments become increasingly important in 2026, understanding Airport Carbon Accreditation requirements, levels, certification process and benefits can help airport operators develop a credible carbon management strategy.
This guide explains everything businesses and airport stakeholders need to know about Airport Carbon Accreditation 2026, including the seven accreditation levels, carbon reporting requirements, verification, benefits and the pathway towards net zero.
What Is Airport Carbon Accreditation?
Airport Carbon Accreditation is a global carbon management certification programme specifically developed for airports. It independently assesses and recognizes airports for measuring and reducing carbon emissions through a progressive framework of seven levels:
- Level 1 – Mapping
- Level 2 – Reduction
- Level 3 – Optimisation
- Level 3+ – Neutrality
- Level 4 – Transformation
- Level 4+ – Transition
- Level 5 – Net Zero
The programme provides a common framework for airports to understand their carbon emissions, establish reduction targets, engage stakeholders and progressively improve their environmental performance.
The programme is site-specific and focuses on the operational activities that contribute significantly to airport carbon emissions. It is designed around continuous improvement rather than treating carbon management as a one-time exercise.
As of 2026, the programme lists 659 accredited airports across its seven levels.
Why Is Airport Carbon Accreditation Important in 2026?
Climate change, ESG expectations and net-zero commitments are changing the way airports approach environmental management.
Airports consume significant amounts of energy through terminal buildings, lighting, heating and cooling systems, ground operations and other infrastructure. In addition, airport ecosystems involve airlines, ground handlers, catering companies, retailers, transport providers and other third parties whose activities can contribute to wider emissions.
Airport Carbon Accreditation provides a structured way to address these emissions.
In 2026, the importance of ACA is increasing because airports are moving beyond basic carbon measurement towards:
- Absolute emissions reductions
- Long-term carbon management
- Scope 3 emissions management
- Stakeholder engagement
- Renewable energy adoption
- Energy efficiency
- Carbon removal
- Net-zero strategies
- Climate-related reporting
The programme's latest technical documentation includes updated requirements for all levels, specific level requirements, verifier requirements and carbon-offset guidance.
Airport Carbon Accreditation Levels Explained
One of the most important aspects of ACA is its seven-level accreditation structure.
Each level represents a higher degree of carbon management maturity.
Level 1 – Carbon Footprint Measurement
Level 1 establishes the foundation for airport carbon management.
At this stage, an airport needs to:
- Determine emissions sources within its operational boundary
- Calculate annual carbon emissions
- Prepare a carbon footprint report
- Demonstrate a policy commitment to reducing emissions
The primary objective is to understand where an airport's emissions come from and how large its carbon footprint is.
This level is particularly useful for airports that are beginning their formal carbon management journey.
However, under programme changes, Level 1 is no longer intended to be a long-term stopping point. Airports are recommended to move to a higher level after two years and are required to upgrade after three years at Level 1.
Level 2 – Carbon Reduction
Level 2 moves beyond measurement towards actual emissions reduction.
An airport must build upon Level 1 requirements and demonstrate:
- Effective carbon management procedures
- A carbon reduction target
- A Carbon Management Plan
- Quantified emissions reductions
- Ongoing monitoring of carbon performance
The objective is to establish a practical system for reducing the airport's carbon footprint.
Typical initiatives may include energy-efficiency improvements, renewable electricity, improved building management systems, efficient airport vehicles and operational improvements.
Level 3 – Optimisation
Level 3 expands carbon management beyond the airport operator.
Airports need to consider relevant Scope 3 emissions and engage third parties operating at or around the airport.
These stakeholders can include:
- Airlines
- Ground handlers
- Catering companies
- Air traffic control
- Retailers
- Service providers
- Employees
- Surface transport providers
Examples of emissions considered at this level can include landing and take-off cycle emissions, passenger and staff surface access and staff business travel.
This makes Level 3 particularly important because an airport's environmental impact cannot always be addressed through the airport operator's own activities alone.
Level 3+ – Carbon Neutrality
Level 3+ builds upon Level 3 and introduces carbon neutrality through offsetting.
Airports must address the emissions over which they have control by using high-quality carbon credits for remaining emissions after reduction measures.
This level therefore combines:
Carbon measurement + carbon reduction + stakeholder engagement + offsetting
However, offsetting should not be viewed as a replacement for genuine emissions reduction. A credible carbon management strategy should prioritize direct reductions before addressing residual emissions.
Level 4 – Transformation
Level 4 represents a significant shift towards long-term and absolute emissions reduction.
At this level, airports need to establish an ambitious long-term strategy aligned with global climate objectives.
Requirements include:
- Policy commitment to absolute emissions reduction
- Expanded carbon footprint
- Long-term absolute emissions reduction target
- Carbon Management Plan
- Emissions reduction trajectory
- Interim milestones
- Stakeholder Partnership Plan
Level 4 also requires airports to actively encourage third parties operating at the airport to reduce their own emissions.
For new applications from September 2025 onward, the programme updated its pathway requirements for Levels 4 and 4+ so that targets should align with an IPCC 1.5°C pathway leading to net zero by 2050, unless the relevant national pathway adopts a 2°C approach through its Nationally Determined Contribution.
Level 4+ – Transition
Level 4+ builds on Level 4 by addressing residual emissions through recognized carbon offsets.
The airport must demonstrate:
- Long-term absolute emissions reduction
- Carbon management planning
- Stakeholder engagement
- Progress towards climate-aligned targets
- Appropriate treatment of residual emissions
The programme describes Level 4+ as compensation for residual emissions using reliable and internationally recognized offsets.
Level 5 – Net Zero
Level 5 is the highest level of Airport Carbon Accreditation.
It represents the programme's most ambitious approach to airport carbon management.
To achieve Level 5, an airport must significantly reduce absolute Scope 1 and Scope 2 emissions and address relevant Scope 3 emissions.
The current Level 5 requirements include:
- Verified Scope 1 and Scope 2 carbon footprint
- Relevant Scope 3 emissions inventory
- At least 90% absolute COâ‚‚ emissions reduction in Scope 1 and 2
- Commitment to net zero in Scope 3 by 2050 or sooner
- Credible carbon removals for residual emissions
- Carbon Management Plan
- Net-zero roadmap
- Stakeholder Partnership Plan
- Continued engagement with the airport's wider ecosystem
This means Level 5 goes considerably beyond simply purchasing carbon offsets. It focuses on deep, absolute emissions reductions and a comprehensive approach to the airport ecosystem.
Airport Carbon Accreditation Requirements in 2026
The exact requirements depend on the accreditation level an airport is pursuing.
However, several elements are fundamental to the programme.
1. Carbon Footprint
The airport needs to establish a reliable greenhouse gas inventory covering the emissions required for its selected accreditation level.
2. Carbon Management Policy
Senior management commitment is important because successful decarbonisation requires organizational support and long-term investment.
3. Carbon Reduction Targets
Higher levels require increasingly ambitious emissions reduction targets.
4. Carbon Management Plan
The Carbon Management Plan explains how the airport intends to achieve its emissions targets.
It can include:
- Energy efficiency
- Renewable energy
- Electrification
- Sustainable infrastructure
- Low-carbon vehicles
- Operational improvements
- Building optimization
- Stakeholder initiatives
5. Scope 3 Assessment
At higher levels, airports need to expand their assessment to relevant Scope 3 emissions.
6. Stakeholder Engagement
Airports need to work with airlines, suppliers, transport providers and other stakeholders to address emissions beyond the airport operator's direct control.
7. Independent Verification
Verification plays an important role in demonstrating that carbon information and programme requirements have been properly assessed.
Airport Carbon Accreditation Certification Process
Although the exact process depends on the airport and target level, a typical ACA journey can be structured as follows.
Step 1: Define the Airport's Operational Boundary
The airport first determines which activities and emissions fall within the applicable boundary.
Step 2: Collect Carbon Data
Relevant energy, fuel, electricity and operational information is collected.
Step 3: Prepare the Carbon Footprint
The collected data is converted into greenhouse gas emissions using appropriate methodologies and emission factors.
Step 4: Develop a Carbon Management Strategy
The airport identifies opportunities for reducing emissions and establishes appropriate targets.
Step 5: Select an Accreditation Level
The airport determines which ACA level matches its current carbon management maturity and future objectives.
Step 6: Prepare Required Documentation
Documents can include:
- Carbon footprint reports
- Carbon Management Plans
- Emissions reduction targets
- Reduction evidence
- Stakeholder plans
- Supporting environmental information
Step 7: Verification
Where required, the application and relevant carbon information undergo independent verification.
Step 8: Accreditation
Following successful assessment against the applicable programme requirements, the airport receives accreditation at the relevant level.
The ACA technical-document library provides separate requirements for all levels, Levels 1, 2, 3/3+, 4/4+ and 5, as well as verifier requirements.
What Are Scope 1, Scope 2 and Scope 3 Emissions at Airports?
Understanding emission scopes is essential for airport carbon management.
Scope 1
These are direct emissions from sources controlled by the airport operator.
Examples may include:
- Fuel combustion
- Airport-owned vehicles
- On-site fuel use
- Certain operational equipment
Scope 2
These are indirect emissions associated with purchased energy, primarily electricity, heating or cooling.
Airports can reduce Scope 2 emissions through:
- Renewable electricity
- Solar power
- Energy efficiency
- Building automation
- Efficient cooling and heating systems
Scope 3
Scope 3 covers other indirect emissions throughout the relevant value chain.
For airports, this can involve areas such as:
- Airline operations
- Passenger surface access
- Staff travel
- Third-party operations
- Suppliers
- Business travel
The significance of Scope 3 increases at higher ACA levels because airport sustainability increasingly depends on collaboration across the airport ecosystem.
Benefits of Airport Carbon Accreditation
Achieving Airport Carbon Accreditation can provide several environmental and strategic benefits.
1. Structured Carbon Management
ACA gives airports a structured pathway for moving from measurement to reduction and eventually net zero.
2. Better Emissions Data
Carbon footprinting helps airport operators identify major emission sources and prioritize action.
3. Improved Energy Efficiency
Carbon reduction programmes can encourage airports to identify energy-saving opportunities.
4. Stronger ESG Performance
A credible carbon management programme can support an airport's broader ESG and sustainability strategy.
5. Stakeholder Collaboration
ACA encourages airports to work with airlines, suppliers, transport operators and other stakeholders.
6. Progress Towards Net Zero
Higher ACA levels provide a framework for airports pursuing ambitious long-term climate objectives.
7. Greater Transparency
Independent assessment and verification can increase confidence in reported carbon performance.
Airport Carbon Accreditation and Net Zero
Airport Carbon Accreditation should not be confused with simply declaring an airport "net zero."
Net zero involves balancing emissions with removals after significant emissions reductions.
ACA provides a structured progression towards that objective.
The journey can broadly be understood as:
Measure → Reduce → Engage → Transform → Address Residual Emissions → Net Zero
Level 5 represents the programme's highest level and requires airports to maintain a net-zero balance for Scope 1 and 2 while actively addressing Scope 3 emissions.
This makes ACA particularly relevant for airports developing long-term decarbonisation roadmaps.
Airport Carbon Accreditation in India
India's aviation sector is expanding, making airport sustainability increasingly relevant.
The Airport Carbon Accreditation programme already includes airports in the Asia-Pacific and Middle East region. The official accredited-airports database includes Indira Gandhi International Airport at Level 5 and Kempegowda International Airport at Level 5, alongside Indian airports at other accreditation levels.
For Indian airport operators and related businesses, carbon management can become an important component of broader:
- ESG strategies
- Environmental management
- Carbon accounting
- Energy management
- Sustainability reporting
- Net-zero planning
- Stakeholder engagement
Organizations preparing for ACA should therefore consider carbon data collection and reduction planning as long-term strategic activities rather than one-time compliance exercises.
Challenges in Achieving Airport Carbon Accreditation
Despite its benefits, achieving higher ACA levels can be challenging.
Complex Carbon Data
Airport ecosystems contain numerous stakeholders, making carbon data collection difficult.
Scope 3 Emissions
Scope 3 emissions can be difficult to measure because they involve activities outside the direct control of the airport operator.
Stakeholder Coordination
Airlines, ground handlers, retailers, suppliers and transport providers may have different sustainability targets and operational priorities.
Infrastructure Investment
Energy-efficient infrastructure, renewable energy systems and fleet electrification can require significant investment.
Long-Term Planning
Higher accreditation levels require airports to establish credible long-term emissions reduction pathways.
Data Quality
Accurate and consistent emissions data is essential for credible carbon management.
These challenges make professional carbon accounting, ESG advisory and sustainability planning increasingly valuable for airport operators and associated organizations.
How Metacorp Can Support Airport Sustainability & Carbon Compliance
Organizations preparing for Airport Carbon Accreditation may need support with carbon management, environmental compliance, documentation, ESG strategy and sustainability planning.
Metacorp can help businesses understand regulatory and environmental requirements and develop structured compliance strategies aligned with their operational needs.
For airports and airport-related businesses, the focus should be on establishing reliable emissions data, identifying reduction opportunities, maintaining appropriate documentation and developing a practical long-term sustainability roadmap.
Professional guidance can also help organizations connect carbon management with broader ESG and environmental compliance objectives.
Airport Carbon Accreditation vs Traditional Carbon Reporting
Traditional carbon reporting generally focuses on measuring and disclosing greenhouse gas emissions.
Airport Carbon Accreditation goes further by providing a progressive management framework.
|
Carbon Reporting |
Airport Carbon Accreditation |
|
Primarily measures emissions |
Measures and manages emissions |
|
Can be a reporting exercise |
Provides a structured improvement pathway |
|
May focus on selected scopes |
Scope requirements expand at higher levels |
|
Limited stakeholder requirements |
Strong stakeholder engagement at higher levels |
|
May not include reduction targets |
Reduction targets become central |
|
No accreditation progression |
Seven progressive levels |
|
Reporting-focused |
Reduction and transformation-focused |
This makes ACA particularly useful for airports that want to demonstrate measurable progress rather than simply publish an emissions inventory.
Future of Airport Carbon Management in 2026 and Beyond
The direction of airport sustainability is moving toward deeper decarbonisation.
Future priorities are likely to include:
- Renewable electricity
- Airport electrification
- Sustainable infrastructure
- Energy-efficient terminals
- Low-carbon ground operations
- Better Scope 3 data
- Sustainable surface transportation
- Stakeholder partnerships
- Carbon removals
- Net-zero roadmaps
- Improved climate reporting
The programme itself continues to evolve. In 2026, ACA published updated programme communications and technical documents, demonstrating that requirements are being refined as climate policy and airport decarbonisation practices develop.
For airport operators, staying updated with the latest ACA technical requirements is therefore important.
Frequently Asked Questions
1. What is Airport Carbon Accreditation?
Airport Carbon Accreditation is a global carbon management certification programme that helps airports measure, manage and reduce their carbon emissions through seven progressive levels.
2. How many levels are there in Airport Carbon Accreditation?
There are seven levels: Level 1, Level 2, Level 3, Level 3+, Level 4, Level 4+ and Level 5.
3. What is the highest Airport Carbon Accreditation level?
Level 5 is the highest level and focuses on maintaining a net-zero balance for Scope 1 and 2 while actively addressing relevant Scope 3 emissions.
4. Is Airport Carbon Accreditation applicable to Indian airports?
Yes. Airports in India participate in the programme, including airports accredited at advanced levels. The official database lists both Indira Gandhi International Airport and Kempegowda International Airport at Level 5.
5. Why is Airport Carbon Accreditation important for airports?
It provides a structured framework for carbon measurement, emissions reduction, stakeholder engagement and long-term climate action.
6. Does Airport Carbon Accreditation address Scope 3 emissions?
Yes. Scope 3 requirements expand as airports progress to higher accreditation levels, with stakeholder engagement becoming particularly important at Level 3 and above.
Conclusion
Airport Carbon Accreditation 2026 provides airports with a structured pathway to measure, manage and reduce carbon emissions. Starting with carbon footprint measurement at Level 1, the programme progressively introduces carbon reduction, Scope 3 assessment, stakeholder engagement, absolute emissions reduction and ultimately net-zero carbon management at Level 5.
As airports face increasing expectations around ESG, climate action and decarbonisation, ACA can serve as an important framework for demonstrating measurable progress.
For Indian airports and aviation stakeholders, understanding ACA requirements early can make it easier to develop accurate carbon inventories, establish realistic reduction targets and create long-term sustainability strategies.
Ultimately, Airport Carbon Accreditation is not simply about obtaining a certificate. It is about building a continuous carbon management system that supports measurable emissions reduction and the long-term transition towards a low-carbon airport ecosystem.