Passenger Terminal World investigates how airports are grappling with the ACI’s new Airport Carbon Accreditation Level 5 certification.
What is Airport Carbon Accreditation Level 5?
According to the ACI, the key differences between ACA Level 5 and Level 4 lie in the scope of emissions covered, the requirements for offsetting and carbon removal, and the depth of stakeholder engagement. “In contrast, Level 4 has less stringent requirements in these areas,” says the organization’s Alexandre de Joybert.
At Level 5, airports are required to achieve at least 90% absolute reductions in their Scope 1 and 2 emissions compared with a 2010 baseline, in alignment with the ISO Net Zero Guidelines. They must also extensively map their Scope 3 emissions, covering all relevant categories as per the GHG Protocol Scope 3 Guidance, including emissions from third parties such as airlines, which are outside the airport’s direct control.
To offset any residual Scope 1 and 2 emissions, airports must invest in credible carbon removal projects, going beyond just purchasing carbon offsets. “The ACI has developed an Offset Guidance Document to inform and guide airports about offset reduction and removal options, requirements and recommendations,” de Joybert explains.
“Level 5 is crucial for positioning airports as leaders in climate action and sustainability”
Alexandre de Joybert, ACI Europe
Additionally, Level 5 requires airports to establish a stakeholder partnership plan, engaging the entire airport ecosystem at a deeper level and actively driving third parties toward emissions reductions, with regular progress milestones.
“To achieve ACA Level 5, airports must adopt a comprehensive and structured approach that builds upon the foundations established by the earlier levels of accreditation. Although it is not mandatory for airports to achieve Level 4 before pursuing Level 5, the requirements for Level 5 are significantly more rigorous and complex, reflecting a mature and advanced understanding of carbon management,” de Joybert concludes.
In December 2023, Airports Council International (ACI) launched what it describes as “the most comprehensive, ambitious and challenging level” of the Airport Carbon Accreditation (ACA) program to date. In short, the new ACA Level 5 certifies airports for reaching and maintaining a net zero carbon balance for emissions under their control (Scope 1 and 2), and extending mapping, influencing and reporting requirements for all other emissions (Scope 3).
According to Alexandre de Joybert, director of sustainability at ACI Europe, Level 5 represents a “significant shift in how airports manage carbon emissions”. He says, “Achieving Level 5 is not just about meeting standards. It’s about leading the way in decarbonization and carbon management while enhancing operational excellence.”
At launch, 10 pioneering airports were accredited ACA Level 5, including Amsterdam Schiphol, Eindhoven and Rotterdam The Hague in the Netherlands – all operated by Royal Schiphol Group; Toulon-Hyères Airport in France, Madeira’s Beja and Portugal’s Ponta Delgada, operated by Vinci Airports; Göteborg Landvetter and Malmö in Sweden, operated by Swedavia; and Christchurch in New Zealand.
Speaking in August 2024, de Joybert confirmed that since launch, another six airports had achieved Level 5, including four Finnish regional airports forming part of the Lapland Airports Group operated by Finavia (Ivalo, Kittilä, Kuusamo and Rovaniemi), and two Indian airports – Kempegowda International and Delhi International. “Their achievement marks a significant milestone for Asia, showcasing the global reach and impact of the ACA program,” de Joybert says.
More recently, Swedavia confirmed that another two of its airports – Stockholm Arlanda and Ronneby – have achieved Level 5. The operator plans to get all 10 of its airports Level 5 certified by the end of 2026.
Level 5 not only emphasizes the reduction of direct emissions – like previous ACA levels – but also mandates collaboration with third parties, such as airlines and service providers, to address their emissions too. “This holistic approach fosters teamwork across the airport ecosystem, ensuring all stakeholders are aligned in their sustainability efforts,” explains de Joybert.
Christchurch Airport first started measuring its emissions nearly 20 years ago and in the late 2000s deployed a Green Transition Plan to look at reducing greenhouse gases.
“Therefore, by the time ACA Level 5 was in development, we had already achieved a 92% reduction in our emissions,” says Claire Waghorn, sustainability transition leader at the airport. “We also already had an active stakeholder partnership plan, and now we’re looking at really drawing out what targets can be set in the most material areas, and what we could be doing to accelerate the achievement of those,” she explains.
“In late August we announced that the solar farm had reached financial investment decision, which means that the money has been committed and the construction can begin,” Waghorn says.
“The solar farm will be complete by the start of 2026,” she continues. “It will generate enough electricity to power 30,000 homes, but what we are really interested in is adding electricity generation, knowing that displacing fossil fuel with clean renewable alternatives will be very energy intensive.”
Other sustainable investments at Christchurch Airport include ground-source heat pumps and at-gate ground power, so airplanes can plug in to renewable electricity at the gate rather than using their auxiliary power units and jet fuel.
“The solar farm will generate enough electricity to power 30,000 homes”
Claire Waghorn, Christchurch Airport
Looking at some of the more challenging areas to decarbonize within the airport, Waghorn says, “Other than the obvious, which is the transition to lower-carbon aviation, we are currently seeking alternatives for our backup diesel generators, which we use for approximately 50 hours a year. Finding zero-emission refrigerants for use in HVAC systems, fully electric fire trucks and de-icing substances is still on our to-do list, as well.”
For other airports looking to achieve ACA Level 5, Waghorn believes contingency is key. “For example, don’t apply when you get to 90% emissions reduced, but rather aim for 92% or greater,” she says. “When you are dealing with such a small number of emissions, any additional unexpected activities can move the dial, and it would be so disappointing to achieve Level 5 then not be able to hold on to it.
“Also, use Level 5 as an excuse to spend more time with the airlines,” she continues. “Ask them what they need, understand their fleet transition timeframes, understand your energy constraints, and help lobby together for the regulatory changes and incentives required to change the industry.”
Schiphol’s Scope 3 mission
Amsterdam Schiphol has been leading the way in sustainability at airports for several years. In addition to being one of the first hubs to achieve Level 5, it was the world’s first airport hub to achieve net zero validation from the Science Based Targets initiative (SBTi) last year.
The airport is continually working to become the most sustainable hub in the world and has several 2030 targets to help it achieve this. These include zero carbon emissions from its direct operations (Scope 1 and 2); becoming a zero-waste facility by preventing waste, increasing recycling and adopting circular economy principles; and promoting sustainable transportation options for passengers and employees.
“Third party stakeholders are in control of which measures they are willing to implement and which they are not,” he says. “To overcome this, we actively collaborate with all our stakeholders and involve them in our decision-making. An example of this is the number and placement of EV charging points at the airport. By actively gathering the input of car rental companies, we can make their implementation of zero-emission vehicles easier.”
Working toward ACA Level 5 accreditation has enabled Schiphol to improve the way it works with stakeholders to reduce Scope 3 emissions. “The reason airports are frontrunners in cutting emissions is twofold: firstly, airports are motivated to contribute to the nationally determined contributions of the countries they are located in. Secondly, by reducing their own emissions and facilitating emissions of partners in the value chain, airports are enablers in the decarbonisation of aviation and related activities in the value chain. This has led to deeper, more systemic partnerships as we want to demonstrate leadership in transforming the entire airport ecosystem.”
Today, Schiphol is actively working with its Scope 3 stakeholders, such as airlines, ground handlers and transportation providers, to reduce emissions. The group uses incentives to encourage airlines to use sustainable aviation fuel. It is also collaborating with ground handlers to replace diesel-powered ground support equipment with electric alternatives and has begun testing ‘taxibots’ to minimize aircraft engine use during taxiing to reduce emissions before take-off and after landing.
“We actively collaborate with all our stakeholders and involve them in our decision-making”
Milad Wariakhial, Royal Schiphol Group
Schiphol is also the lead in an EU-funded project called TULIPS, which is working on developing innovations that facilitate the transition to low-carbon mobility and enhance sustainability at airports. “Within this project we have trials ongoing covering everything from a hydrogen GPU and iron flow battery to carbon sequestration using biochar [a charcoal-like substance produced by the pyrolysis of biomass],” Wariakhial explains.
Collaboration at Swedavia
Swedavia owns and operates 10 of Sweden’s busiest airports. In 2020, it became the world’s first airport operator to become fossil-free in its own operations.
To date, four of the group’s airports have achieved ACA Level 5 and, according to Therese Forsström, head of the group’s environmental department, it is only a matter of time before the other six become accredited.
“All our airports are currently ACA Level 4+ accredited,” reports Forsström. “The ACA certifications last three years, so we are waiting for the existing certificates to expire before renewing each airport and hopefully achieving Level 5. Our goal is that by 2026 all our 10 airports will be Level 5.”
“There are likely to be a lot of adjustments needed at the airport before we can provide hydrogen fuel”
Therese Forsström, Swedavia
To help its stakeholders achieve these targets, Swedavia is doing a lot of work related to more sustainable aircraft. Earlier this year, Swedavia signed an MoU with Airbus, Avinor, SAS and Vattenfall to work together to develop infrastructure for hydrogen aviation at airports in Sweden and Norway. “There are likely to be a lot of adjustments needed at the airport before we can provide hydrogen fuel,” notes Forsström. “And this MoU will help us determine the best way forward.”
Circularity is another big focus for Swedavia. The airport operator is currently exploring ways it can reuse waste to reduce its impact on the environment. “We must become more circular than we are today, so we are mapping out where we are today, the gaps and where we want to be in the future,” says Forsström.
“One project we are carrying out in this area is soil reuse,” she continues. “During construction work at the airport there is often a lot of soil waste, and instead of removing it with trucks we are exploring how it can be circulated at the airport. This reduces CO2 emissions and costs. We are doing the same thing with glass in windows.”
Forsström believes that for projects of this kind and for improving the sustainability of the whole airport campus, direction and collaboration are essential. “To achieve ACA Level 5, for example, airports must have management buy-in. Management must set clear targets for teams to work toward. Close collaboration with all airport stakeholders is also essential – we are all working toward the same goals, so we need to stop operating in silos and come together for a cleaner, and greener future.”
This article originally appeared in the September 2024 issue of Passenger Terminal World. To view the magazine in full, click here.
