Carbon Removal at Airports (2024)
Chapter: 4 Case Studies
CHAPTER 4
Case Studies
4.1 Introduction
It was incredibly difficult to identify applicable carbon-removal case studies at airports. When the study was initiated, there were few airports that were evaluating carbon-removal technologies. Therefore, it is important to note that some of the following case studies are not carbon-removal projects, but rather carbon-reduction projects that provide lessons learned that are applicable to carbon-removal evaluation, challenges, and implementation. The following case studies were selected because of the current carbon reduction and removals underway or being evaluated at these airports:
- Southwest Wyoming Regional Airport, Rock Springs, Wyoming: Driving Change—Innovative Airport–Developer Partnership
- Denver International Airport: Regenerative Carbon-Removal Landscaping Opportunities
- San Diego International Airport: Driving Innovation Through Creative Pathways—Carbon Offset Portfolios and Local Nonprofit Donations
- Indianapolis International Airport: Lessons Learned from a Carbon Capture Project—Potential Future Link to Carbon-Removal Pathways
- Finavia International Airport, Finland: A Spotlight on European Trends: The Path to Net Zero
- Christchurch International Airport, New Zealand: Level 5 ACA and Potential Carbon-Positive Achievement
4.2 Southwest Wyoming Regional Airport, Rock Springs, Wyoming
The Southwest Wyoming Regional Airport (RKS) in Rock Springs, Wyoming, is focused on sustainability, including reducing its carbon footprint and supporting its community by driving local economic development. Carbon-removal companies are active in the area due to the unique geologic formation in the region, known as the Rock Springs Uplift, which is well-suited for carbon storage. As a result, the airport director has been working with several companies to evaluate the feasibility of constructing a DACS project at the airport. These discussions have led to a unique teaming arrangement between the airport and the developers, as they partner to work through airport-specific (and other) opportunities and hurdles surrounding CDR. They first established a partnership agreement to work together exclusively for a period of 12 months on all decarbonization efforts. This allows the airport and the developer to share information and collaborate closely on scoping the right carbon-removal project for the airport. CDR companies are constantly reevaluating the costs and benefits of different types of carbon-removal projects. Available federal funding is different for carbon-removal projects for
Driving Change—Innovative Airport–Developer Partnership
the purpose of reuse (i.e., development of SAF) versus carbon-removal projects for the purpose of sequestration. As such, the developer must evaluate which carbon-removal project would be more cost-effective. RKS’ partnerships have given the research team the clearest example of the process needed to implement an on-airport carbon-removal project.
Specific areas of focus to date include the following:
- Pore space lease: A key feature of the proposed project is Rock Springs’ unique geologic formation with its availability of pore space underground. To sequester carbon in this pore space, a Class VI well is needed. The airport and developer are working together on a lease agreement for that pore space in terms of years, lease bonus payment, and in terms of a per-ton-of-CO2-injected fee. The airport worked with the FAA to apply existing advisory circulars and fair market value processes from the FAA and Department of Interior to meet airport lease requirements and fair market value requirements. This lease negotiation and terms are still under development to determine the interplay between the lease of pore space and the sequestration benefits.
- Surface lease: The pore space lease will be supplemented by a surface lease to account for project-associated infrastructure on the airport property. This could include renewable energy to power the DAC process, the DAC units, as well as other aboveground infrastructure (e.g., roadways and utilities). Once details of the surface use are finalized, the airport will work with the FAA to update its ALP and seek concurrent use approval. As with the pore space lease, the surface lease is still under development and fair market value and other considerations are being studied.
- Sale of the credits: The airport wanted to have the ability to sell locally generated, third-party-certified offset credits to its general aviation and commercial aviation customers to support the growth of the CDR economy in southwest Wyoming. To do this, the airport entered into a marketing agreement with the private developer to gain access to their produced credits. In exchange for selling these credits to airport users, the airport will be able not only to support the local growth of the CDR industry but also to assist customers with their decarbonization goals. At the same time, they will be creating a new source of revenue for the airport through a marketing fee on every credit sold. The deal also allows the airport itself to purchase carbon-removal credits to further its decarbonization goals.
Overall, RKS is helping drive the process of carbon-removal projects and, to date, is the first known airport that has closely been coordinating with a developer to try to implement a large-scale DAC and sequestration project on airport property.
4.3 Denver International Airport, Denver, Colorado
With about 52 mi2 of land area, Denver International Airport (DEN) owns the second largest tract of land of any airport in the world. The management of its land is supported by DEN’s Division of Real Estate, focusing on supporting aviation core services, as well as beneficial development for nonaviation land and support of the airport’s overall sustainability goals. DEN recently completed a landscape strategy plan, to focus on land-management opportunities within the context of detailed airport considerations and the potential to use some of the land as a carbon sink (see Figure 23). The available land type is a viable option for soil-based carbon removal.
Regenerative Carbon-Removal Landscaping Opportunities
The plan evaluated five goals, including carbon sink, energy, water quality, habitat producing, and partnerships. The strategy looked at minimum standards (compliance) compared to where measures could provide net-positive benefits with increased carbon sequestration and additional
Figure 23. Regenerative landscape strategy.
environmental and social co-benefits. It also examined ways to design regenerative landscape, providing a carbon sink, enhancing viewsheds, engaging the community, and meeting airport wildlife compliance (which is a noted challenge with most land-use-based carbon-removal pathways) and stormwater requirements.
Based on these goals, the plan created design intents, standards, landscape materials, paving, visual screens, snow fences, and grading requirements, among other criteria, to enhance sustainable landscaping, with an eye to carbon-removal opportunities. The plan also includes goals to track carbon removal in the long term. Challenges for these types of land-use-based measures include the ability to track the carbon removal over the long term. While DEN can estimate the carbon-removal potential, certifying it toward a net-zero goal would be challenging. DEN is unique in its amount of available land, though this type of evaluation can be scaled for other airports with smaller amounts of available land. DEN does not currently have plans to certify the projects as offsets.
4.4 San Diego International Airport, San Diego, California
The aviation industry is facing the same challenges as many other industries when it comes to differentiating and prioritizing carbon-reduction efforts (point capture or reducing or preventing CO2 from entering the atmosphere) compared with carbon-removal efforts (pulling CO2 directly out of the atmosphere). The difference between carbon-avoidance offsets and carbon-removal offsets is one that is developing quickly as guidance on net-zero certifications is currently underway. Carbon-removal pathways, both nature-based and technological, are nascent and undergoing rapid development, making it challenging to evaluate developers and CDR pathways, including the technical details, verification processes, and how airports can support these projects.
Driving Innovation Through Creative Pathways: Carbon Offset Portfolios and Local Nonprofit Donations
San Diego International Airport (SAN), shown in Figure 24, is owned by the San Diego County Regional Airport Authority (Authority). SAN is recognized as one of the leaders in sustainability in the aviation industry and is currently one of only three airports in North America that is certified to Level 4+ (Transition) under the ACA program through ACI–NA. To reach this
Figure 24. San Diego International Airport, aerial view.
level, the airport must demonstrate that it continues to reduce its directly controlled carbon emissions (such as emissions from building energy use and fleet vehicles) and that these reductions track with net-zero emissions targets defined by the IPCC through the implementation of a carbon-management plan, along with other requirements.
The Authority’s efforts to reduce emissions currently are dedicated to increasing energy efficiency, transitioning to clean transportation, utilizing renewable energy, and exploring other decarbonization strategies, including evaluating CDR pathways. Finally, the airport must offset its remaining direct carbon emissions, as well as business travel emissions, to achieve Level 4+.
To date, these emissions have been offset through The Good Traveler, a carbon-offset program that the Authority developed. These offsets have historically involved carbon-avoidance projects or projects that may qualify as removals but were not necessarily separated out as such. During the last few years, discussions with The Good Traveler have increasingly focused on including carbon-removal projects within its portfolio as carbon-removal pathways are evolving quickly. Additionally, the Authority has continued to evaluate whether on-site projects could be feasible to provide local benefits. However, given that the Authority owns only 661 square acres, of which 14 are set aside for state- and federally protected migratory birds from April through September, there is extremely limited space to use for nonoperational activities at SAN, either for developing a technological CDR project or for a land-use project. As a result, carbon-removal potential for the airport would likely need to come through support of off-airport projects. Because on-site project potential is limited, the Authority is evaluating their next steps toward net zero, collaborating with The Good Traveler and the San Diego Foundation, a regional community foundation in San Diego, to facilitate donations to local, mission-aligned nonprofits via its Climate Initiative program.
While most of these collaborations currently focus on reduction, the Authority continues to evaluate carbon-removal pathways in two primary ways: (1) by advocating for an increased presence of carbon-removal projects within The Good Traveler offset program portfolio and (2) through the evaluation of technologies that could be implemented as pilot projects at SAN or through donations via the San Diego Foundation that could include support for new types of CDR projects. The Authority is a good example of how to push for CDR technology advancement outside developing a project on airport property or merely purchasing offsets. It also highlights the importance of evaluating what offsets are being purchased. The portfolio may not meet all the criteria for carbon-removal offsets or may only partially meet these criteria.
4.5 Indianapolis International Airport, Indianapolis, Indiana
The distinction between carbon capture, sequestration, and full carbon removal is a current challenge in the aviation industry. While there have been few carbon-removal projects on or by airports, projects that leverage carbon-capture technology and sequester CO2 within pavement can serve as valuable case studies that illuminate the differences and potential opportunities to transition to carbon removal as the technology evolves. One such example is the Runway 5R-23L and Taxiway D Strengthening and Capacity Enhancement Project at the Indianapolis International Airport (IND).
Lessons Learned from a Carbon Sequestration Project: Potential Future Link to Carbon-Removal Pathways
IND is ranked as one of the top 10 busiest U.S. airports in terms of air cargo and is home to the second largest FedEx hub in the world, making the airport a crucial link in the movement of freight across the globe. Its owner and operator, the Indianapolis Airport Authority (IAA), is amid a multiyear Runway 5R-23L and Taxiway D Strengthening and Capacity Enhancement
Project, involving full-depth portland cement concrete reconstruction and necessary improvements to drainage, electrical, and navigational aids. The project cost estimate is $290 million, representing a major project for the airport and surrounding region.
Project Spotlight
The Runway 5R-23L and Taxiway D Strengthening and Capacity Enhancement Project is the first airfield project in the world to receive the prestigious Envision Platinum recognition.
Project Owner: Indianapolis Airport Authority
Project Partners: Circle City Aviation Partners, a Kimley-Horn & Woolpert joint venture, and C&S Companies, sustainability and Envision integration services
Contractors: Walsh Construction and Milestone Contractors
Although runway reconstruction projects are standard at airports, the IAA’s emphasis on sustainability and resilience resulted in an outstanding example of sustainable infrastructure development as evidenced by its Envision Platinum award through the Institute for Sustainable Infrastructure. One of the project’s most notable achievements included the first-ever FAA-approved airfield design using in situ CO2 mineralization technology. This involves incorporation of in situ CO2 mineralization into concrete production, which introduces postindustrial CO2—captured as a waste by-product from manufacturing processes—to freshly mixed concrete. The addition of CO2 can improve the compressive strength of concrete without impacting other properties, enabling the use of less cementitious material while achieving equivalent performance. The project team conducted extensive research to ensure its feasibility of application, to improve overall project performance without any negative trade-offs to either the project over its lifetime or to the environment.
Additionally, the project team sought to incorporate specific sustainable design guidelines for sourcing postindustrial CO2, ensuring the project’s concrete mix designs remained within a targeted threshold for kilograms of CO2e per yd3 of concrete. As such, the project’s total embodied carbon emissions will be reduced by 15 percent, from a baseline of 131,160 tons CO2e to 111,742 tons CO2e.
Incorporating the use of in situ CO2 mineralization technology into concrete production (which qualifies as carbon sequestration by the IAA) requires capturing CO2 from industrial processes that would otherwise have been emitted into the atmosphere (which qualifies as carbon capture by the upstream entity, in this case Helget Gas Products). Once captured, the CO2 is refined and able to be injected into concrete during the mixing process, where it mineralizes and becomes embedded in the concrete, with permanence ranging from 40 to 100 years depending on the reuse and recycling of the construction materials at the end of the project’s useful life (see Figure 25). In the future, the IAA may be able to transition from the use of captured carbon and sequestration to complete carbon removal if the technology uses CO2 pulled from the ambient air via DAC (subject to refinement prior to use). While this would increase costs on the project, it would also open the organization up to potential incentives through the federal government, like those included in the IRA for DAC.
4.6 Finavia Airports, Finland
Finavia is a leader in decarbonization within the aviation industry. Currently, all 20 airports in its group are carbon neutral for Scopes 1 and 2 emissions, with a goal of net zero by 2025. The four Lapland airports (Rovaniemi, Kittilä, Ivalo, and Kuusamo) have reached net zero. Helsinki will follow in 2024, and the rest will achieve net-zero emissions in 2025. Net-zero emissions will be required to align with their aspirations to achieve the new Level 5 certification in the ACA. In the long run, Finavia airports are aiming toward carbon negativity, which cannot be achieved without carbon removal. Therefore, they are evaluating carbon-removal opportunities within their system.
A Spotlight on European Trends: The Path to Net Zero
Five of Finavia’s airports have reached Level 4+ (Transition) in ACI’s ACA program. This level of commitment entails substantial stakeholder engagement to reduce Scope 3 emissions, reduce
Figure 25. On-site batch plant.
Scope 1 and 2 emissions to as low as possible, and offset remaining Scopes 1 and 2 emissions. Currently, Finavia airports have leveraged bioenergy and wastewater projects for emission credits, which are considered avoidance credits. Emissions reductions and offsets at Finavia airports have been achieved through many means. However, even with substantial reductions, residual emissions will need to be addressed with carbon-removal projects to meet net zero.
Looking to the long term, Finavia is investigating eligible carbon-removal offsets to pursue ACA Level 5 (released in December 2023). However, Europe is having similar challenges to the United States with the credibility of the offset market, as well as the ability to differentiate between carbon-avoidance projects and carbon-removal projects and the associated offsets; this difference will need to be understood to achieve the definition of net zero for the ACA certification program. The future of removal markets is still in flux, and the ability to comply with Article 6 of COP 26 introduces the issue of double-counting [United Nations Framework Convention on Climate Change (UNFCCC) 2016]. Double-counting occurs when one carbon-removal offset is counted more than once. Article 6 allows countries to transfer carbon credits and carbon-removal offsets, which creates opportunity for accounting errors such as double-counting. The Finnish government is currently pursuing measures for forest owners to be paid for enhanced carbon capture. Since these would be included in the national carbon inventory, airports would not be able to apply their reductions toward their emissions footprint calculation, as that would be double-counting the credits.
The European Union has proposed an initiative to develop necessary rules to monitor, report, and certify carbon removals; this is an integral step for integrating carbon removals into European Union climate policy. Until the carbon-removal market gains more certainty, Finavia airports will continue to be diligent in pursuing accountable removal offsets. Tracking the carbon-market changes and regulations will be key in pursuing net zero for any airport in a credible way.
4.7 Christchurch International Airport, New Zealand
Christchurch International Airport has aggressive climate goals and already achieved net zero in 2021, with a target of absolute zero by 2035. The airport is currently working with industry partners and focusing on how to accelerate decarbonization of the entire aviation sector. As of 2022, the airport has achieved a 94 percent reduction in Scope 1 and Scope 2 emissions. The airport saw this progress through sharing responsibility for the green transition across the company and a multitude of projects that ensued. This included the 100-percent transition of its corporate fleet to electric vehicles, while the airport is currently working through utility vehicle transition. Additional decarbonization efforts include the electrification of equipment, such as installation of a ground source heat pump heating and cooling system (which uses the ambient temperature of underground aquifers and heat exchange technology to replace diesel generators); gate ground power; energy-efficient lighting; circular waste solutions; and use of smart building technologies. Once the airport achieved a 90-percent reduction in Scopes 1 and 2 emissions, they decided to remove the remaining emissions through best practice sequestration.
Level 5 ACA and Potential Carbon-Positive Achievement
The airport investigated different carbon-removal options to find the highest integrity offering on the market. This included looking at domestic and international programs. However, the airport found New Zealand–based permanent native forestry (certified through the New Zealand Emissions Trading Scheme) offered the best example of traceability, monitoring, and co-benefits. The airport also has partnered with local landowners to support native permanent forestry in both the Central Otago region and the Banks Peninsula region to assist with reforestation and biodiversity improvements. The project will not only reduce GHG emissions but also capture biodiversity benefits and improve soil quality, enhance water ways, and increase resilience through use of native tree species.
Climate Action Background
- Net zero from 2021, absolute zero by 2035
- Pilot airport for ACA Level 5; achieved Level 5
- Reduction of 94 percent in Scopes 1 and 2 emissions
- Commitment to offset or remove 120 percent of carbon footprint to be climate-positive
Future reductions to help the wider aviation sector decarbonize (by producing zero-emission fuels) include the development of a 400-hectare on-site renewable energy precinct, known as Kōwhai Park. This starts with a 170-megawatt solar farm (see Figure 26), currently scheduled to be operational by the end of 2024 or beginning of 2025. The solar farm will provide green electricity to the airport campus and future electric aircraft and will power the production of green hydrogen. The airport is also a party to the New Zealand Hydrogen Consortium, alongside Airbus, Air New Zealand, Fabrum, Fortescue Future Industries, and Hiringa Energy to better understand the requirements for future aviation and the aviation hydrogen supply chain.
Figure 26. Christchurch Airport.
