Taking flight to net zero with Airport Carbon Accreditation Level 5

Making an effective, measurable impact on airport carbon emissions is no easy task without expert support. It requires broad-ranging experience in decarbonizing operations within airport facilities and a holistic approach using a multidisciplinary team to make progress.

Airports face multiple challenges on their decarbonization journey due to their complex operation and many moving interrelated functions. One of the most fundamental is the takeoff and landing of aircraft—a major contributor to scope 3 emissions, which are outside of the direct control of the airport—but also the reason for the airport to exist in the first place. Although airport emissions require a complex, well-planned process of measurement and reduction, solutions are comparatively easier to implement for scope 1 and 2 reductions than for scope 3 emissions.

To assist airports in decarbonizing, the Airport Carbon Accreditation (ACA) is a global program that independently assesses and recognizes their efforts to manage and reduce carbon emissions. It supports the industry’s goal of achieving net zero carbon emissions by 2050 by helping airports measure and report emissions, contributing to the overall decarbonization of aviation. With more than 500 participating airports worldwide, the ACA program signifies substantial progress towards sustainability and environmental responsibility.

The unique demands of ACA Level 5

The ACA framework, and its associated tools, provide a level playing field for airports looking to have their decarbonization efforts recognized. Some have already reached Level 5, the highest level possible, and we expect more to do the same in the next year or so as industry focus switches to scope 3 emissions reductions.

ACA's Level 5 requires airports to maintain a net zero balance on scope 1 and 2 emissions. They also need to address scope 3 emissions, by actively engaging with third parties to drive emissions reductions, and utilize carbon removals for any residual emissions.

Airport Carbon Accreditation level 5 differs from level 4+ in several ways:

• The scope 1 and 2 carbon footprints need to be independently verified as reaching and maintaining ≥ 90% absolute CO₂ emissions reductions.
• The inclusion of scope 3 categories should be more detailed, per the requirements of the Greenhouse Gas Protocol Scope 3 Guidance.
• Scope 1 and 2 reduction targets need to be stronger.
• A scope 3 emission reduction target of net zero by 2050 must be included.
• Relevant organizations within the value chain must be included in the stakeholder partnership plan.
• Airports must use credible carbon removals instead of offsets.

An integrated approach to airport scope 3 emissions

Scope 3 emissions, primarily tied to aircraft takeoff and landing, pose a significant decarbonization challenge for airports. Yet there are still opportunities to influence emission reductions, despite the lack of direct airport control over this area of operations.

The key is to recognize the interconnectedness of all the emissions-contributing elements of an airport—an understanding that becomes the foundation upon which a net zero roadmap can then be built. This acts as a guide for airports and supports their efforts to achieve emissions reductions.

Crucially, a practical decarbonization roadmap involves setting milestones. This sets out a realistic framework of achievable targets and is a useful tool against any greenwashing claims by providing more focus points for accountability. It also empowers airports to allocate resources efficiently, focusing on areas that will yield the most significant carbon reduction. Stakeholder partnership plans are also an ACA Level 5 requirement and ensure that all emissions-contributing parties understand that decarbonization requires a unified, holistic approach and that they are actively involved in the process.

A decarbonization approach needed by airports to address the complexity and range of challenges also requires a multidisciplinary, collaborative team with experience from multiple sectors to support it.

From offsets to carbon removals

ACA Level 5 mandates a shift from traditional offsets to carbon removals. Unlike offsets, removals actively extract carbon from the atmosphere, and are important for a few reasons:

• The Intergovernmental Panel on Climate Change (IPCC) states that carbon dioxide removal (CDR) is critical in achieving net zero by 2050, by addressing any residual carbon emissions once all emission reduction efforts have been exhausted.
• CDR includes both nature-based removals—for example, wetland restoration, blue carbon management (carbon storage in the ocean), reforestation, and others - as well as technology-based removals such as bioenergy with carbon capture and storage and direct air capture and storage.
• Current obstacles include high costs and technical challenges. Uncertain regulatory requirements also make this market hard to navigate.
• Early investors in CDR will support market development, accelerate growth (including developing business models and financing mechanisms), and become climate leaders in the forefront of creating an essential net zero industry.

Strength in collaboration

Level 5 accreditation presents many complex challenges. The intricacies of scope 3 reductions, particularly those associated with aircraft takeoff and landing, demand innovative solutions. The nascent carbon removal landscape also presents its own set of challenges such as prohibitive costs, technical obstacles, and regulatory uncertainties.

However, Level 5 accreditation is not without opportunity. Beyond the environmental benefits, developing an achievable roadmap towards decarbonization can also support the airport in securing government funding and advocating for government and utility support.

ICF's Climate Center, as well as our Climate Resilience, Electrification, Energy, and Aviation teams regularly work together to support airports in assessing and addressing emissions from diverse sources. This collaborative approach allows us to identify strategic areas for intervention on optimal resource allocation and time investment.

With expert guidance, airports can overcome the challenges of decarbonization and position themselves as pioneers in a net zero future.