How we identify the highest-quality carbon removal

With global temperatures steadily rising above pre-industrial levels, Carbon Dioxide Removal (CDR) has become essential for limiting warming to below 2°C and reaching climate goals. As more companies look to offset emissions, investing in reliable, high-quality CDR credits is critical to avoid greenwashing and maintain stakeholder trust.

Navigating the complexities of CDR quality is challenging. As the leader in Direct Air Capture (DAC), Climeworks is uniquely qualified to establish a framework to ensure high-quality carbon removal. This framework provides clear criteria to identify credits that deliver real, lasting carbon removal. We use it to create comprehensive carbon removal portfolios that combine various vetted approaches, both engineered and nature-based, ensuring that our customers receive the most effective solutions for their goals.

Climeworks’ quality framework for carbon removal

This framework integrates our own expertise with established standards, such as Microsoft’s “Criteria for High-Quality CDR”, Shopify’s “Buyers Guide”, and WBCSD’s carbon removal guidance, helping us select only the highest quality credits for our portfolios.

Our criteria center on three pillars: trust, impact, and risk. Trust ensures that each credit represents a full metric ton (1,000 kg) of CO₂ removed, impact assesses durability, scalability, and added benefits, and risk considers any potential downsides of a given CDR approach. By quantifying these aspects, we provide a science-based evaluation that helps us deliver the most credible and effective carbon removal solutions on the market.

Figure 1: The three core pillars of Climeworks' quality framework: Trust, impact, and risk.

Trust: ensuring confidence in CDR

The credibility of carbon removal (CDR) hinges on one critical principle: after accounting for all emissions related to a project—whether from construction, operation, or any other source—the result must be net CO₂ removal. Each credit must unequivocally represent the removal of one ton of CO₂ from the atmosphere.

To ensure this standard, Climeworks builds trust on four pillars: measurability, end-to-end carbon accounting, additionality, and third-party certification. These attributes collectively guarantee the integrity and impact of every CDR credit sold.

Measurability ensures that the amount of CO₂ removed is quantified accurately, using reliable techniques applied at appropriate intervals. To avoid over-crediting, conservative methods are key—measurement uncertainties are addressed with confidence intervals or buffers.

Beyond measuring CO₂ sequestered, measurability includes establishing a baseline: what would have occurred without the project. While baselines often assume zero, this is not always the case. For example, in reforestation projects, expected natural regeneration must be quantified and deducted to credit only additional CO₂ removal. High-quality projects rely on robust methods to ensure only verified, additional removals are counted.

End-to-end carbon accounting ensures that only verified net CO₂ removals are credited. It starts by determining gross CO₂ removal—measured removals minus the baseline scenario—and deducting all emissions tied to the project’s lifecycle, including those from materials, energy use, and final storage. This comprehensive assessment, often done through lifecycle analysis (LCA) calculates net CDR by subtracting emissions from gross removals thus capturing "grey emissions" from cradle to grave. At Climeworks, we only issue ex-post credits—those based on removals that have already occurred, not forecasts (see Figure 2).

Figure 2: Waterfall chart showing the steps from measured CDR to net-adjusted credits (tons CO₂), accounting for baseline emissions, LCA, and conservative accounting.

Additionality evaluates whether a carbon removal project would occur without the planned intervention or the sale of credits. High-quality credits in the Voluntary Carbon Market (VCM) meet three criteria:

Carbon additionality: The removal wouldn't happen otherwise.

Legal additionality: The project isn’t legally mandated.

Financial additionality: The project depends on credit sales for its feasibility.

All three must be fulfilled to confirm that the credit represents a truly additional climate benefit.

Third-party certification ensures that CDR credits meet established carbon standards. Developers must follow strict methodologies for CO₂ removal, including accurate measurements and lifecycle emissions accounting. Independent bodies verify adherence and carbon standards issue credits via public registries, ensuring transparency and avoiding double counting.

At Climeworks, every credit must be certified under a recognized registry, providing a baseline quality check. However, as standards and methodologies vary widely, certification alone doesn't guarantee top quality. That’s why Climeworks conducts thorough technical due diligence on every project to uphold the highest standards.

Impact: beyond carbon removal

High-quality CDR projects deliver more than just CO₂ sequestration. They address critical aspects like permanence, social and environmental co-benefits, availability and scalability, and price, which collectively determine their overall impact. Considering these dimensions helps buyers evaluate how a project contributes to long-term climate goals while supporting broader environmental, social, and economic objectives. By weighing these factors, stakeholders can make informed decisions that balance cost, quality, and sustainability.

Permanence refers to how long a project keeps CO₂ out of the atmosphere, determined by the storage method. Longer storage, such as geological sequestration, offers greater climate impact and credit quality compared to shorter-term storage in biological systems like reforestation, though protective measures can extend the latter’s lifespan. The choice of permanence also depends on the use case for the credit: Credits with long-term storage are essential for offsetting fossil emissions, as recommended by the Oxford Principles, ensuring alignment with regulations and standards like the EU’s Carbon Removals and Carbon Farming Regulation and the Science-Based Targets initiative (SBTi).

Social and environmental co-benefits go beyond CO₂ sequestration, serving as key indicators of a project’s potential for long-term success. These include creating jobs, strengthening local economies, and engaging communities to foster support for CDR activities. Projects that assist marginalized groups or improve food security, for example, can have a significant impact. Environmentally, CDR initiatives can boost biodiversity and protect ecosystems from threats like soil erosion and wildfires. A thorough evaluation of these benefits ensures that CDR investments lead to sustainable and comprehensive outcomes.

Availability and scalability assess the volume of CDR credits available today and in the future. While short-term availability is crucial, scalability becomes a priority for buyers seeking large volumes to offset emissions over time. Future scalability depends on the project’s potential for growth, resources, and approach limitations. At Climeworks, we focus on sustainable scaling, considering factors like energy, land, water use, and waste production.

Price is a key consideration for cost-sensitive buyers, especially when purchasing large volumes. To assess the right price, companies may compare the cost of in-house CO₂ abatement, the profit per ton of CO₂ emitted, and the social cost of carbon, which ranges from USD 100 to USD 1,000 per ton. While price can correlate with quality factors like permanence and co-benefits, a higher price doesn’t always guarantee better quality.

Risk: managing challenges for reliable CDR

CDR projects inherently involve a range of risks, from direct CO₂-related risks like storage reversal or leakage to broader societal and environmental challenges. Quantifying these risks involves assessing their probability and potential severity (see risk matrix below) while evaluating mitigation strategies. This approach provides clarity on which risks are tolerable and informs whether a CDR credit meets the quality standards necessary for purchase. The following sections address key risk categories.

Figure 3: Risk matrix visualizing how the likelihood of an event (horizontal axis) and its severity (vertical axis) combine to yield a risk score. Scores range from low (green) to high (red), guiding prioritization of mitigation actions.

Storage reversal risk refers to the potential release of sequestered CO₂ back into the atmosphere, undermining the project’s climate benefit. Reversals may occur unintentionally, through events like wildfires or seismic activity, or deliberately, such as through unauthorized land use changes. High-quality projects mitigate these risks through careful site selection, robust monitoring systems, and preventive measures. For instance, geological storage has lower reversal risks than nature-based solutions, but both require tailored risk management. Buffer pools or reserve credits are commonly used to account for potential reversals. Climeworks ensures safe, permanent CO₂ storage for its Direct Air Capture plants by selecting sites carefully and partnering with storage providers adhering to best practices and strict safety protocols.

Leakage occurs when CDR efforts inadvertently lead to increased emissions elsewhere. This can happen locally, for example, when agricultural land is repurposed for CDR, displacing farming activities to new areas and causing deforestation (activity shifting leakage). It can also occur economically, such as when reduced timber supply from a project increases logging elsewhere (market leakage). Best-in-class projects address leakage during development by carefully selecting locations and materials while monitoring for unintended emissions throughout the project lifecycle.

Social and environmental risks can arise from poorly implemented CDR projects, negatively impacting local communities and ecosystems. Social risks may include displacing communities, disrupting livelihoods, or infringing on land rights, particularly for marginalized groups. Environmental risks range from biodiversity loss and soil degradation to water overuse and ecosystem harm. High-quality projects address these risks by fostering transparent stakeholder engagement, providing equitable community benefits, and performing thorough environmental assessments. At Climeworks, close collaboration with host communities and adherence to strict environmental standards ensure responsible CDR deployment.

Execution risks pertain to whether a project can deliver on its promised CO₂ removal. Financial instability, operational inefficiencies, or inexperienced management can jeopardize a project’s success. Transparent communication about progress, setbacks, and methodologies is essential to building trust. Reliable project developers with strong operational frameworks help reduce execution risks. At Climeworks, rigorous evaluation of potential suppliers and their projects ensures high standards are met and maintained.

Conclusion

While the CDR market may seem complex and evolving, the path forward is clear. Investing in high-quality CDR projects today not only brings us closer to meeting net-zero targets but also positions us to benefit from growing demand in the future. This framework outlines the key criteria Climeworks uses to vet CDR projects, ensuring that they meet rigorous quality standards. By following this approach and conducting thorough due diligence, buyers can confidently invest in solutions that deliver real climate impact, while also contributing to a sustainable, scalable, and impactful carbon removal future.