Direct Air Capture, Simply Explained

Key Takeaways

• Emissions cuts alone are not happening fast enough to meet global climate goals. Direct air capture (DAC) removes carbon dioxide (CO₂) that is already in the atmosphere. It has become one of the fastest-growing carbon removal approaches even as it stays capital-intensive.
• DAC's core advantage is flexibility. Because the atmosphere fully mixes within about two weeks, a DAC facility can be sited almost anywhere with clean power and CO₂ storage and still deliver the same climate benefit.
• DAC investment has grown to roughly US$2.2 billion across 37 specialized companies since 2021. Per-tonne costs (currently US$500–1,000 or more) remain the technology's central barrier to scale.
• US federal support for DAC is still unsettled. The US Department of Energy cut its regional DAC hub program from a planned US$3.5 billion to roughly US$1.2 billion between October 2025 and April 2026. This is a signal that deployment funding, not the underlying science, is DAC's biggest near-term risk.

What Is Direct Air Capture?

Direct air capture (DAC) works by sucking in air, filtering it to remove CO₂ that has built up over time and still sits in the atmosphere. To be effective, DAC must draw a lot of air into separating equipment like filter banks or cooling towers. This is similar to the small-scale systems that have scrubbed CO₂ from air in spacecraft and submarines for decades. From there, CO₂ filtering typically involves a chemical process that binds the CO₂ for release later. While the most commonly used chemical compounds in this process are liquid solvents or solid sorbents, other chemical, electrical, and physical processes could also work.

After the filtering process, the captured CO₂ is usually stored in one of two ways. The most important is geological storage, which keeps CO₂ out of the air and oceans indefinitely in deep geological formations (typically a mile down or more) and offers the clearest climate benefits. The second is storing the CO₂ in products like concrete, which offers clearer commercial benefits. A new generation of mineralization projects is expanding this second pathway, turning captured CO₂ into building materials rather than only storing it underground. In addition, CO₂ can be recycled into fuels and chemicals, which prevents net-new CO₂ from being released but does not count as a carbon removal solution since these materials are eventually used, releasing the captured CO₂ back to the atmosphere.

The Advantages of Direct Air Capture

DAC has many advantages as a CO₂ removal approach. First and foremost, it's scalable. In effect, there are no practical limits to our ability to scrub CO₂ from the sky or store it in deep geological formations around the world. This means scaling can be fast and removals profound.

It's straightforward. The devices remove CO₂ from the air, a meter measures it, and operators store and monitor that CO₂. It's clearly additional (meaning it only happens with financial and human intervention), easily verified, and durable (stored for many hundreds of years or more), meeting the bar set by our own Criteria for High-Quality Carbon Dioxide Removal.

It has a small physical footprint. Typical DACe systems do the carbon removal work of trees with 1,000–2,000 times less space. This leaves more room for conservation, agriculture, rewilding, and other important work.

It can be done anywhere with low-carbon energy and CO₂ storage options. Globally, our atmosphere mixes fully every two weeks, meaning that CO₂ released in China or Australia arrives over the US (and vice versa) in this amount of time. Because of this, DAC facilities can be sited anywhere and still have a climate benefit—as long as there is sufficient clean energy available and options for CO₂ storage or use are nearby. This reduces competition for land and provides opportunities for economic development in regions with the right resources.

Finally, and most critically, DAC is a backstop technology. While reducing emissions remains the top priority, there are certain types of emissions that are either very hard or very expensive to abate. The last fraction of hard-to-abate emissions can be managed through DAC, effectively capping global costs to reach net-zero emissions. In fact, the more rapidly DAC scales and deploys, the less total energy and cost are needed to achieve key climate goals.

Challenges and Concerns of Direct Air Capture

Like all climate mitigation approaches, DAC has challenges. The primary challenge today is cost. Today's large-scale systems cost roughly US$500–1,000 or more per tonne of CO₂ removed, depending on the technology and site, though several developers are targeting US$100–150 per tonne over the next 10 years. Although the costs will come down over time through deployment and wider adoption, today's high costs are a barrier to investment and deployment.

Another challenge is around the energy requirements associated with DAC. Pulling one million tonnes per year of CO₂ out of the air requires roughly 200–300 megawatts of zero-carbon energy (a combination of heat and electricity). Given the limited supply of zero-carbon energy available today, there is a valid question about whether this is the best use of that resource today.

Finally, there is the question of environmental risks and community burdens of DAC. Experience to date suggests that the total environmental burdens and consequences of this pathway are among the lowest of any clean energy and climate technology. But since DAC systems involve heavy equipment and chemicals, questions about the full environmental risks and burdens to communities remain, especially given its limited commercial deployment. Although most DAC systems will be sited in remote locations, not near communities, and pose no serious environmental risks, reasonable concerns must be addressed before permitting and building future DAC projects.

Why the Excitement Now?

Although current climate science and added urgency from organizations like the Intergovernmental Panel on Climate Change (IPCC) have driven interest in DAC, other important advances have fed broad interest and excitement about its potential. Since 2017, DAC technology has matured greatly, including the deployment and operation of many projects around the world. Costs have dropped, new pathways have opened, and private investment in DAC-specific companies has reached roughly US$2.2 billion across 37 companies since 2021. 

Two large facilities illustrate where deployment stands today. Climeworks' Mammoth plant in Iceland has been operating since May 2024, although not at full capacity. Occidental's Stratos plant in Texas remains delayed past its most recent 2026 second quarter target due to a component issue, with no confirmed new startup date as of this writing. Both facilities carry substantial commercial offtake agreements from aviation, energy, insurance, and tech companies, agreements that continue to hold even as construction timelines have slipped.

In part, interest results from new policy advancements. In the US, the Inflation Reduction Act's 45Q tax credit, maintained under the 2025 One Big Beautiful Bill Act, currently provides US$180 per tonne for DAC paired with dedicated geologic storage, with added parity for utilized CO₂. The Department of Energy's Regional Direct Air Capture Hubs program, originally planned at US$3.5 billion, was cut back sharply in an October 2025 review. It was then partially restored in April 2026 when the Department of Energy confirmed its two flagship projects, Project Cypress in Louisiana and the South Texas DAC Hub, would proceed. The program's total is now expected to be near US$1.2 billion. In addition, California has amended its Low-Carbon Fuel Standard to allow DAC as a compliance mechanism, and the US Department of Energy has explored a pilot program to purchase valid, durable carbon dioxide removal, including DAC. Recently, the Carbon Dioxide Removal Leadership Act was introduced to Congress, which would require the Secretary of Energy to remove CO₂ directly from ambient air or seawater.

Other programs around the world reflect this growing interest. In the UK and EU, governments have promised CO₂ removal purchases this decade, which will likely include DAC. Research programs have begun in Canada, the UK, Germany, Japan, and China. Developing nations increasingly see DAC as a potential new industry and hope to take advantage of their natural resources to expand energy access while being paid to remove CO₂ from the air and oceans.

The Future of Direct Air Capture

I'm pleased to have played a small role in DAC's new prominence. I've had the good fortune of being at DAC project groundbreakings and ribbon cuttings, led the first-ever government grants program for DAC, worked with scientists to develop new DAC technologies, published analysis over a decade ago on the need for DAC, and testified before the US Congress on the benefits and needs of DAC on three separate occasions. Based on my experience in DAC over the last 16 years, I believe that smart investment, policy, deployment, and community engagement will convert the promise of DAC into thousands of projects. These projects will help avoid the worst outcomes of climate change and restore some natural balance to the world. With federal support now concentrated on fewer, better-resourced flagship projects, rather than spread across two dozen early-stage hubs, the DAC field is being pushed toward fewer high-profile delays and more repeatable, bankable deployments.

Frequently Asked Questions

How does direct air capture differ from capturing carbon at an industrial site? 

Industrial, or point-source, capture removes CO₂ at a smokestack, where concentrations are high. Direct air capture removes CO₂ that is already spread throughout the open atmosphere. DAC facilities can operate almost anywhere with available clean power and storage, not only next to a specific emitter.

Is direct air capture actually operating today, or is it still experimental? 

Direct air capture is operating today; it is not just experimental. Climeworks' Mammoth plant in Iceland has been running since May 2024, and dozens of smaller facilities are active worldwide. However, the largest US projects, including Occidental's Stratos plant in Texas, are still working through startup delays. Once it begins operating, DAC will be fully commercial, although limited in deployment.

How much does it cost to remove one tonne of CO₂ with direct air capture? 

Current large-scale direct air capture systems cost roughly US$500–1,000 or more per tonne of CO₂ removed, depending on the technology and facility site. Several developers are targeting costs of US$100–150 per tonne later this decade, though that has not yet been demonstrated at commercial scale and is likely to take 10 years or more to achieve

Does using direct air capture reduce the need to cut emissions? 

No. Direct air capture is a backstop for emissions that are difficult or costly to eliminate outright, not a substitute for cutting emissions in the first place. Reducing emissions remains a priority; DAC addresses both what is left over (residual emissions) and what’s already in the air and oceans.

Key Takeaways

• Near-term role for carbon removals: The revised Science-Based Targets Initiative (SBTi) Corporate Net Zero Standard (CNZS) v2.0 proposes requiring or recognizing interim carbon dioxide removal (CDR) targets before companies reach net zero. This shift aims to scale up the CDR industry in line with climate science and ensure companies address residual emissions earlier rather than deferring action until their net-zero target year.‍
• Revised target frameworks and increased accountability: The draft standard introduces key changes, including separate targets for scope 1 and 2 emissions, enhanced scope 3 target-setting guidelines, and the recognition of market-based mechanisms for indirect mitigation of scope 3 emissions. It also requires companies to publicly disclose transition plans and assess implementation progress against targets.‍
• Potential for stronger action on removals: While the proposed updates are a step forward, the final standard should make near-term CDR targets mandatory rather than optional and should expand to include those for projected scope 3 residual emissions, not just scope 1. Without these stronger mandates, demand for early-stage CDR investments may remain limited, potentially slowing progress toward net-zero goals.‍
• Companies should prepare now: Businesses should start integrating CDR into their climate strategies now so they are equipped to navigate procurement of high-quality removal credits in the voluntary carbon market. Preparing ahead of the final CNZS v2.0 release will help companies align with science-based decarbonization pathways and demonstrate climate leadership.

What the Latest SBTi Update Means for Corporate Climate Action

On 18 March, 2025, the Science Based Targets Initiative (SBTi) released its draft Corporate Net Zero Standard (CNZS) v2.0, significantly updating its framework for corporate net-zero target setting for the first time since 2021. The draft proposes new approaches for companies to support carbon dioxide removal (CDR) in the transition to net-zero emissions, a move that could help scale the nascent CDR industry.

This release is part of a broader revision, with key proposed updates including:

• Requiring public disclosure of transition plans after companies set targets.
• Separating targets for scope 1 and 2 emissions.
• Enhancing the scope 3 target-setting framework using an impact-based prioritization process.
• Recognizing indirect mitigation (e.g., book-and-claim commodity certificates) for hard-to-trace scope 3 emissions.
• Defining a role for emissions removals in the transition to net zero.
• Providing options to recognize company leadership in beyond value chain mitigation (BVCM).
• Assessing corporate progress against targets to bolster accountability.

While formal recognition of removals in the transition to net zero is a positive step, stronger incentives will be needed in the final CNZS to ensure companies take meaningful early action on CDR. The draft standard is open for the first of two public consultations until 1 June, 2025, with a finalized version expected to launch in 2026.

What Remains the Same From the Current Standard?

SBTi’s framework remains focused on three core requirements for companies:

• Reducing emissions year-on-year to reach an approved science-based target (SBT) by 2050 or earlier.
• Investing in beyond value chain mitigation (BVCM) in the transition to net zero to support near-term global decarbonization efforts.
• Neutralizing remaining emissions from the net-zero year (achieved after at least 90% emissions reductions) and onwards with high-quality, permanent carbon removal.

Carbon credits representing emissions reductions and removals remain ineligible for meeting reduction targets within a company’s value chain (SBTs).

What’s New in CNZS v2.0 for Carbon Removals?

Until now, the SBTi encouraged companies to invest in CDR through mechanisms such as BVCM, but has not proposed requiring removal before their target net-zero year. As a result, organizations had little clarity or incentive to invest in CDR ahead of their net-zero target date, dampening near-term demand for carbon removal and delaying the industry's growth.

The new draft changes this by proposing three options for the V2.0 Standard that address the impact of residual emissions during the transition to net zero:

• Option 1 (requirement): Companies are required to set near- and long-term removal targets, including interim CDR milestones,¹ to address projected residual emissions.
• Option 2 (optional with recognition): Companies can set and receive recognition for removal targets to address projected residual emissions.
• Option 3 (flexibility of mechanism): Companies have the flexibility to address expected residual emissions either entirely through additional emissions reductions within their value chain, entirely through removals, or via a combination of both.

Notably, all three approaches apply only to residual scope 1 emissions.

On top of these approaches, SBTi has suggested two options for the minimum durability threshold of CDR purchases in their draft standard. Removals will either need to follow a ‘like for like’ approach,² where CDR storage must match the atmospheric lifetime of residual emissions, or a gradual transition approach, where carbon storage durability increases over time.

Why Mandating CDR Matters

Mandating near-term CDR reinforces the need for immediate climate action, ensuring that carbon removals complement emissions reductions rather than being deferred until the net-zero target year. The urgency of early CDR investment is clear:

• Limiting global warming to well below 2°C above pre-industrial levels requires removing billions of tonnes (gigatonnes) of carbon dioxide annually by mid-century.
• The CDR industry is in its early stages and requires sustained investment today to scale in time.
• If companies wait until their net-zero year to purchase CDR, the supply of high-quality removal credits is unlikely to be sufficient.

As part of the proposed removal targets in Option 1 (above), the CNZS v2.0 would require companies to gradually increase CDR purchases over time, ramping up to 100% of a company’s projected residual scope 1 emissions in the net-zero target year (<10% of baseline year emissions).³

What More Can Be Done?

The potential introduction of required removal targets would be a significant and welcomed step, reinforcing the importance of near-term CDR investment to support industry maturation and climate goals. However, mandatory near-term CDR targets represent only one of three potential pathways for the V2.0 standard. Moreover, neutralization of residual emissions on the path to net zero is only proposed for scope 1 emissions. While the SBTi provides clear rationale for this,⁴ SBTi should not let the complexity of projecting scope 3 emissions be a barrier to climate change mitigation. Scope 3 emissions represent the majority of emissions from SBTi-aligned companies. Furthermore, companies with high scope 3 emissions typically have a higher ability to pay compared to their industrial counterparts with high scope 1 emissions.

If interim removal targets are made optional, and scope 3 emissions remain excluded, the demand signal for near-term CDR will be limited. The public consultation (and advice of Expert Working Groups that SBTi is convening) will be essential in determining which proposed guidance matures into the final standard; consultation feedback can be provided here prior to June 1, 2025.

How Businesses Can Prepare for CNZS v2.0

Companies aligning with SBTi’s evolving guidance should begin to integrate CDR into their climate strategy now. This means:

• Understanding their residual emissions forecast and planning early investments.
• Developing a company-specific climate strategy to incorporate CDR into their sustainability roadmaps in tandem with plans to reduce value-chain emissions.
• Engaging early in the voluntary carbon market to implement these strategies and develop procurement processes to support high-quality removal projects.
• Ensuring credibility by selecting removal projects aligned with scientific best practices.

Conclusion: A Step in the Right Direction, But More Certainty Is Needed

The CNZS v2.0 draft represents a critical turning point for corporate climate action with options to formalize the role of early CDR investment through interim removal targets for signatories. However, SBTi must take a stronger stance in the final version of the revised standard by choosing to adopt requirements for near-term neutralization (rather than leaving this optional), including projected residual scope 3 emissions in near-term CDR targets, aligning durability requirements with climate science, and defining removal quality standards to ensure these efforts drive meaningful climate impact. Organizations seeking to align with this guidance should prepare by developing a comprehensive climate strategy that accounts for science-based decarbonization pathways and recognizes the role of early-stage investment in CDR solutions.

Key Takeaways

1. The decision to fund a project is determined by a holistic review of project development maturity. This applies across capital-intensive projects, including low-carbon power generation, carbon capture and storage (CCS) solutions, sustainable aviation fuel (SAF), and broader transition infrastructure build-out. Both technical and commercial workstreams must be developed in parallel to avoid project failure. 
2. Early scope decisions, such as site selection, core technology selection, and nameplate capacity, are cheap to make but become exponentially disruptive and costly to reverse. 
3. Independent challenge and verification is tangible evidence of a disciplined, well-managed capital development process. 

Bridging the Gap from Announcement to Delivery

Among project developers, a perception often persists: seeking external review signals a project in distress. In capital budgeting discussions, subjecting engineering scope and commercial assumptions to third-party interrogation can be misconstrued as a vote of no confidence in the primary delivery team.

In reality, the reverse is true. Across complex infrastructure, independent challenge is the disciplined stage-gate practice that protects capital by reconciling technical reality with commercial terms before designs are locked.

Independent Challenge Is a Sign of Strength, Not Doubt 

Across capital projects, and in particular within emerging low-carbon industrial infrastructure, the gap between announced projects and delivered assets remains stark. Data from the Mission Possible Partnership’s Global Project Tracker reveals that fewer than 17% of announced commercial-scale clean industrial facilities worldwide have reached Final Investment Decision (FID) or commercial operations, leaving more than 800 major decarbonization projects stalled in front-end development.

The causes of developmental paralysis are multifaceted. While macroeconomic interest rate shifts and global supply chain disruptions sit largely outside a developer's control, project definition and developmental discipline remain entirely manageable. Even amid external volatility, a project designed with resilience will have a far greater likelihood of success.

Independent review and assurance directly strengthen a project’s chance of success and overall value. Large global project delivery organizations have applied this discipline for decades by deploying independent teams to evaluate project readiness at every stage gate. For teams lacking a dedicated internal oversight organization, or those deploying first-of-a-kind facilities, third-party independent review provides the necessary rigor to facilitate project success.

Relae’s (formerly Carbon Direct) work with Stockholm Exergi is a clear example: independent assurance helped build funder and regulator confidence in a first-of-a-kind carbon removal facility with no direct precedent to benchmark against.

Why Projects Stall Between Announcement and FID 

Low-carbon infrastructure and net-zero industrial projects carry unique risks compared to the repeat delivery of established designs. Exciting new developments run a higher risk of falling victim to optimism bias or compressing development timelines to meet public announcement milestones.

It is a natural human tendency for project champions to focus on the upside during early development. However, early momentum must be balanced with processes that reintroduce industrial lessons, supply-chain realities, and operational resilience.

Front-End Loading (FEL) is a well-evidenced approach for improving capital project outcomes. Decades of benchmarking by Independent Project Analysis (IPA) show that approximately two-thirds of industrial megaprojects suffer capital cost overruns or schedule slippage of 25% or more, or encounter severe operational problems lasting more than two years post-startup. This pattern is repeating in low-carbon infrastructure: IPA’s analysis of 12 completed low-carbon projects found average cost escalation of 31% and schedule slip of almost 50%. Rigorous front-end definition remains the single strongest predictor of whether a project will achieve its cost and schedule targets. 

As highlighted in the CDR 2.0: Five Pillars of Successful Project Deployment and Delivery report published by Relae, projects falter when developers push ahead without stress-testing the full delivery framework. Stage gate reviews are the mechanisms that evaluate the total project concept and underlying business case. They are most effective when executed as independent cold-eye evaluations prior to each funding gate, identifying and mitigating vulnerabilities long before final investment decisions are reached. 

What Funders Need to See at Each Gate 

Different stages of project development rely on distinct capital sources, each requiring specific proof points before deploying funds.

Before FEED Funding: Justifying the Engineering Spend

Front-End Engineering Design (FEED) is a major financial commitment, typically costing between 2% and 4% of total project capital cost. The funders backing this stage are usually the developer’s own balance sheet equity, strategic partners, or public grant programs. Before allocating millions of dollars to detailed engineering, these funders need confidence on the fundamentals:

• A technically sound process concept, confirmed utility balances, and an energy integration scheme that fits the site.
• Secured site control, clear zoning pathways, and no environmental fatal flaws that could derail permitting.
• Documented availability of required feedstocks, water and power, paired with demonstrable interest from target off-takers.

Before FID: Proving Bankability and Commercial Closure

As a project approaches FID, the funding audience shifts to conservative commercial lenders, infrastructure funds, and binding offtake counterparties. These capital providers are not underwriting strategic vision; they are underwriting long-term operational cash flows and debt service. Depending on the project and financing structure, capital providers may require:

• A high-confidence capital cost estimate (AACE Class 2 or Class 3) backed by frozen Piping and Instrumentation Diagrams (P&IDs), firm equipment quotes, and a realistic execution schedule with clear critical paths.
• Bankable engineering, procurement, and construction (EPC) structures that clearly allocate risk, include performance guarantees and enforceable liquidated damages.
• Fully executed, binding offtake and feedstock agreements, along with non-appealable permits and completed utility interconnection agreements, with remaining conditions clearly understood.
• An objective, third-party challenge review that assesses operational viability and distinguishes an executable engineering plan from an aspirational concept.

Commercial and Technical Co-Development: The Stage-Gate Method in Practice

A project rarely fails because of an isolated mechanical issue or a purely commercial misstep; failure happens when technical decisions and commercial terms are negotiated in silos and decisions are made without understanding of the wider implications. 

We see this disconnect play out in several ways, including: 

• Sizing capacity before testing market demand: An engineering team may size a facility to maximize thermodynamic efficiency and economies of scale, only for the commercial team to discover buyers will only commit to half that volume. The developer is left with an oversized, unbankable design requiring fundamental rework. 
• Setting product specifications before negotiating offtake: Process engineers frequently design systems around standard vendor packages. However, when downstream transport, processing, or storage networks enforce strict purity standards, the facility faces costly equipment redesigns. This issue has materialized directly within European CCS networks. Open-access offshore storage operators, such as Norway's Northern Lights project, established strict cross-border CO₂ specifications requiring tighter moisture and impurity thresholds than originally designed for. 
• Locking Electrical Loads Prior to Interconnection Verification: As detailed in Relae’s analysis of physical infrastructure bottlenecks, scale is rarely constrained by capital availability; it is dictated by electrical transmission queues, substation headroom, and 24/7 firm power availability. Freezing electrical demand before verifying utility interconnection timelines risks stranding engineering work on an asset that cannot connect to the grid. 

How Relae Stress Tests Projects at Each Gate 

Independent reviews at each stage-gate improve success rates by stress-testing assumptions before presenting to lenders, infrastructure investors, or corporate buyers. Relae reviews projects across five categories using the TECOP framework:

• Technical: Verifying technology readiness levels (TRL), mass and energy balances, plot plan constructability, and operational availability under real-world conditions.
• Economic: Capex benchmarking, operating contingency adequacy, utility tariff sensitivities, and financial model cash-flow resilience.
• Commercial: Offtake agreement structures, feedstock contracts, contracting boundaries, EPC contract structures, and counterparty creditworthiness.
• Organizational: Owner's team capabilities, internal stage-gate governance, contractor oversight mechanisms, and execution capabilities. 
• Political: Statutory permitting status, regulatory durability, carbon market policy exposure, and local community social license.

The TECOP framework is relevant for evaluating delivery risk across all project types, see more in Relae’s Criteria for High-Quality Carbon Dioxide Removal, Delivery Risk Appendix.

What makes this approach effective is sitting on both sides of the table. Having completed over 250 deep-dive technology reviews, 900+ project evaluations, and advised on more than $6 billion in industrial project finance, Relae has extensive experience evaluating the considerations important to institutional funders and buyers.

The Value of Early Independent Project AssuranceIncorporating independent review should be standard practice for modern infrastructure delivery. Because funders will perform their own rigorous diligence regardless, conducting an independent evaluation early enables developers to address vulnerabilities proactively and present a more resilient business case.

Commissioning an independent team for a cold-eye review during early project formation can be a  cost-effective way to identify potential risks before they become expensive to address. Catching an unworkable process assumption, an oversized capacity plan, or a misaligned commercial interface during pre-FEED costs a tiny fraction of what it takes to fix those issues during construction

Ultimately, independent challenge is not an admission of doubt, but the disciplined stage-gate practice that protects capital by reconciling technical reality with commercial terms before designs are locked, signaling to partners, and your future funders that your project is built to deliver. 

To dive deeper into the frameworks that support successful projects, read Relae's white paper: CDR 2.0: Five Pillars of Successful Project Deployment and Delivery and take a look at project assurance in action through our Stockholm Exergi Case Study.

Frequently Asked Questions

What is independent project assurance?

Independent project assurance is a structured review of a capital project by a team that sits outside the project’s delivery organization. Reviewers test the engineering scope, cost estimate, schedule, commercial agreements and permitting position against what funders will require at the next stage gate. The developer receives a clear list of gaps, risks and proposed mitigations prior to presenting the project to lenders, investors or buyers.

When should a developer commission an independent project review?

Periodically throughout the project development process - at a minimum before each major funding gate, but smaller reviews are also beneficial at earlier stages when key concept and technology decisions are being made. A review before Front-End Engineering Design (FEED) tests whether the process concept, site and supply of feedstock, water and power justify the engineering spend. A review before Final Investment Decision (FID) tests whether the cost estimate, EPC structure and binding agreements will satisfy lenders. Site, technology and capacity decisions are cheap to change in pre-FEED and expensive to reverse once detailed engineering starts.

What does an independent project review assess?

Relae structures its reviews around the TECOP framework, which covers five risk areas: technical (technology readiness, mass and energy balances, constructability), economic (capex benchmarking, contingency, financial model resilience), commercial (offtake, feedstock and EPC contracts), organizational (owner’s team capability and stage-gate governance) and political (permitting, regulatory durability and social license). Reviewers also check that technical and commercial decisions are aligned, because projects often fail where the two are developed in silos.

How does an independent project review differ from lender due diligence?

An independent project review applies a holistic approach identifying not only gaps, but also opportunities to add value and strengthen the business case. Lender and investor due diligence is often purely looking at risks and gaps, prior to committing capital. Lender diligence protects the funder and reports its findings at a point when changes are costly and can delay financial close. A developer-commissioned review takes place earlier, so the project team can fix weaknesses in scope, cost or contracts before funders see them.

Key Takeaways

• Biochar is the fastest-growing durable carbon removal method in the voluntary carbon market, accounting for 93% of all durable removal volumes contracted in the first quarter of 2026 alone.
• Scientists still have an incomplete understanding of biochar durability in soils, and there is some uncertainty regarding biochar's ultimate climate impact.
• Biochar carbon removal crediting must reflect conservative, science-based estimates of durability to safeguard against overcrediting.
• Relae’s (formerly Carbon Direct) detailed analysis highlights the key scientific issues affecting biochar soil durability to better inform credible carbon removal.

Biochar Is Gaining Momentum in Carbon Removal

Biochar has entered the spotlight as a scalable climate solution. It is being adopted for its carbon storage potential and agricultural co-benefits. Commercial uptake of biochar has expanded dramatically since 2019 and continues to accelerate, due to the voluntary carbon market. In the first quarter of 2026 alone, 2.3 million tonnes of total durable carbon dioxide removal (CDR) have been contracted, with biochar accounting for 93% of that volume, driven substantially by a single Microsoft-Liferaft deal for one million tonnes. Established and emerging CDR registries have developed biochar protocols and are certifying biochar carbon credits.

In addition to CDR, biochar can bring numerous co-benefits when it is applied to soil. These benefits include improved water and nutrient retention, pH adjustment, and pollution remediation. In agricultural and forage systems, improvements in soil quality following biochar application can lead to enhanced plant growth. Biochar also promotes rural economic development and can be a part of a circular economy that stewards its resources judiciously.

As purchases of biochar credits grow, a central question has not yet been fully answered: How durable is biochar carbon storage, and what are the best methods to assess this? This blog explores the science of biochar durability, also known as permanence, and how credible science can inform the carbon removal market.

What Is Biochar and How Is It Made?

Biomass heated in an oxygen-deficient environment produces biochar, a solid, carbon-rich material. In the near or full absence of oxygen, that process is called pyrolysis. Biochar can be produced from various kinds of biomass, including agricultural or forest residues, construction debris, organic waste, seaweed, and more. Biochar is also gaining attention for its potential as an ingredient within engineered materials, such as cement.

Biochar achieves CDR by durably storing carbon dioxide (CO₂) that was removed from the atmosphere via photosynthesis and plant growth. Carbon stored in living plants will stay stored during the plant’s lifespan. Once it dies, a plant’s biomass decomposes, cycling most of the stored carbon back into the atmosphere. By introducing technological interventions into this carbon cycle, such as using pyrolysis to produce biochar, the carbon that nature captured via photosynthesis can be stored longer than it would have been otherwise. Pyrolysis converts some of the carbon from biomass into chemical compounds with a higher resistance to environmental degradation. How much carbon converts to these more recalcitrant forms depends on the type of biomass used and the heating conditions, including temperature and time. After biochar is produced, the highly recalcitrant fraction of carbon can be stored for long periods of time, as long as the biochar does not combust.

Common methods of biochar production include:

• Industrial pyrolysis systems: Modern pyrolysis systems heat biomass in a low or no-oxygen environment, creating biochar and gaseous compounds known as synthesis gas. Synthesis gas is typically combusted in a controlled system to provide heat for the system. Low air emissions can be achieved for these systems, which is important to maximizing the environmental benefits of biochar production.
• Modular pyrolysis systems: Smaller, transportable pyrolysis units serve farm-scale or decentralized production. Unlike open kilns, these systems retain temperature control and sensor-based monitoring similar to industrial pyrolysis, and some use autothermal designs that recycle non-condensable gases for heat rather than relying on an external energy source. This makes them a middle option for smaller producers seeking more process control and emissions oversight than open-kiln methods allow, without the capital cost of a large, fixed industrial plant.
• Kon-Tiki kilns: This is a less complex and, therefore, more widely deployable method of biochar production. However, air pollution from this method is likely to be higher than from industrial pyrolysis and can be significant enough to undermine the carbon benefits of biochar production. In Kon-Tiki kilns, biomass is burned in an open-top, conical kiln. Biomass is continually added to the process and finally quenched with water.
• Trench mounds: Trench production is one of the simplest forms of biochar production and is used often by smallholder farmers. Biomass is buried in a trench, covered, and combusted to produce biochar. Air pollution from tench mound production is likely to be significant and even higher than from Kon-Tiki kilns.  

How Biochar Durability Is Quantified

Durability, or permanence, is a key metric used to quantify carbon removal from biochar; it describes the amount of carbon that remains stored in biochar for 100 years or more after it is applied to soil.

Quantifying durability relies on experiments and models to project permanence. There are a number of established and emerging approaches to evaluating biochar recalcitrance to chemical decomposition and storage permanence. Most of these are based on short-term incubation experiments in laboratories, where scientists seal biochar in a container with other organic matter and measure carbon changes over a period of weeks to months. These approaches typically treat biochar as having multiple pools of carbon that differ in their ability to resist decomposition.

While these experiments offer insights into decomposition dynamics, they have two significant limitations. First, these approaches do not measure biochar decomposition and durability in the real world (e.g., after biochar is applied to agricultural soils), meaning they do not capture the effects of actual soil and other environmental factors. Research has shown that different soils can strongly influence decomposition rates. Second, the short duration of these experiments means there is significant potential for error in extrapolating the results to time periods of centuries and beyond.

Why Quantifying Durability Accurately Is Critical

Biochar CDR certification methodologies use a range of approaches to quantify permanence. Most commonly these are based on biochar’s chemical composition, namely the hydrogen-to-organic-carbon ratio (H/Corg). Models that correlate H/Corg with projected permanence, from decay models applied to biochar decomposition experiments, are used to calculate a permanence factor. Other quantification methods include measuring the random reflectance of biochar to estimate the amount of highly recalcitrant carbon in biochar.

The risks of inaccurate durability estimates for carbon removal buyers are significant. Overestimating durability can lead to ineffective CDR spending, reputational risk from overstated climate impact, and delayed progress on net-zero and compliance goals. Buyers need to understand and engage with durability estimation methods to ensure they are procuring high-quality biochar credits.

Why Underground Coal Isn't a Valid Durability Comparison

Recent research proposes a new approach to quantifying biochar durability. The authors assert that random reflectance—a parameter developed in the field of organic petrology (the study of organic matter in rocks)—can be used to characterize durability. Using a component of coal (known as "inertinite") as an analogue for biochar, they propose a benchmark random reflectance of 2% as an "inertinite benchmark" for biochar. They argue that the entire fraction of biochar that meets that benchmark will degrade over approximately 100 million years. This is a large departure from other estimates of biochar durability, and we believe this to be at odds with more conservative models.

There are several reasons to doubt this method. The coal-biochar analogy is inadequate because coal buried underground is not exposed to the same degradation conditions as biochar in soil. Underground coal has lower exposure to oxygen, water, and ultraviolet light, all of which are plentiful in surface soils. Each of these is associated with well-understood decay mechanisms. Furthermore, the process of geologic burial dramatically changes the physical structure of organic matter. Additionally, the permanence factor that the reflectance method allows (i.e., up to 100% carbon retention over extremely long time scales) contradicts experimental evidence that some carbon loss will occur over years or decades.

Subsequent research from the same authors has since recommended pairing random reflectance analysis with H/Corg rather than relying on either alone. This is a refinement of the original approach meant to support more reliable quantification of biochar durability and avoid overcrediting CDR from biochar.

Where Biochar Science Is Headed Next

Biochar stability science will keep advancing. Research into biochar degradation pathways in soil will continue to refine permanence models and inform the relevance of coal analogues. Long-term field measurement studies, with a high density of in-soil sampling to quantify persistence over time, should be a near-term priority that biochar CDR projects can contribute to. Additional studies should investigate pathways to increase durability and rigorously develop modern isotopic, spectroscopic, and chemical techniques for enabling robust assessments of biochar durability.

Crediting Biochar Means Getting Durability Right

Biochar is a promising solution for both soil health and climate impact. Nevertheless, carbon removal certification protocols will need updating as the science of biochar durability evolves. Relae cautions against excessively generous claims of biochar CDR durability, in both permanence factor and timeframe, given the important uncertainties outlined above.

Protocols should not outpace science in terms of permanence assessment, and crediting should stay rooted in an understanding of what drives biochar permanence that is backed by science, including production conditions (e.g., high temperatures) and biochar composition (i.e., low H/Corg). At a time when investment in biochar is booming and the science of biochar is evolving, the voluntary carbon market must keep pace.

Frequently Asked Questions

Is biochar carbon negative?
Biochar can provide net carbon dioxide removal when the amount of carbon durably stored exceeds the emissions associated with producing, transporting, and using the biochar. Plants capture CO₂ from the atmosphere through photosynthesis and store that carbon in biomass. Left alone, most of that carbon returns to the atmosphere within years to decades as the biomass decomposes or burns. Converting biomass to biochar stabilizes a portion of that carbon into forms that can stay stored for centuries or longer, delivering a net removal once those production emissions are accounted for..

Is biochar considered an engineered, hybrid, or nature-based carbon removal solution? Biochar is considered a hybrid carbon removal solution because it combines natural carbon uptake through photosynthesis with a technological intervention. Biomass first removes and stores atmospheric carbon as it grows, and pyrolysis then converts a portion of that biomass carbon into more stable forms that keep carbon from returning to the atmosphere for longer periods.

How do carbon removal registries currently estimate biochar's durability? Registries use decay models based on biochar's ratio of hydrogen to organic carbon (H/C_org ratio), which correlates with how resistant the biochar is to microbial breakdown, combined with environmental factors where biochar is applied, like soil temperature, moisture, and application context, to estimate what fraction of the carbon remains stable (i.e., not converted back to CO₂) over a defined timeframe. Methodologies typically also require third-party lab testing of feedstock and pyrolysis conditions to substantiate durability claims. Some registries and methodologies also incorporate random reflectance as part of durability quantification, although the scientific basis for using reflectance to estimate long-term biochar durability remains under debate.

How long does biochar actually store carbon? 

Biochar does not have a single storage lifetime. Some of its carbon decomposes relatively quickly, while more stable fractions can remain stored for centuries or longer, depending on the biochar’s properties and the conditions where it is stored. Because these estimates rely on models rather than direct observation, carbon crediting has to balance two risks: crediting more durability than actually exists, and being so conservative it undercredits real removals and threatens project viability.

Key Takeaways

• Trust in carbon credits remains low. In part, this is because many mistakenly treat every credit type as interchangeable.
• Reduction, removal, and avoidance credits are verified against fundamentally different baselines, so credit quality must be judged based on type and project specifics, never with one blanket standard.
• The Integrity Council for the Voluntary Carbon Market's Core Carbon Principles now give buyers an independent bar to check against, including 44 methodologies approved across 13 eligible crediting programs, as of August 2026.
• Removal credits still make up only 5–6% of the market, even as compliance-driven demand accelerates, per our 2026 State of the Voluntary Carbon Market report.

Three Types of Carbon Credits: Reduction, Removal, and Avoidance

A carbon credit is a mechanism that allows one party to compensate another for their carbon mitigation activities. Based on their net emissions impact, there are three types of carbon credits: reduction, removal, and avoidance. 

1. Reduction credits reflect activities that decrease greenhouse gas emissions, compared to prior practices. 
2. Removal credits reflect activities that remove carbon dioxide already present in the atmosphere and oceans and lock it away for decades, centuries, or millennia.
3. Avoidance credits reflect activities that prevent greenhouse gases from being emitted in the first place. For all three types, credits are assessed and issued by measuring or estimating how much carbon is reduced, removed, or avoided as a result of a credit purchase and its associated activities.

While credits are assessed in different ways depending on the type, one of the most important indicators of quality is a project's baseline - the emissions that would be present in a business-as-usual scenario, without action being taken to reduce, remove, or avoid them. Project developers use baselines as a means of comparison to assess the net emissions impact of a project. 

• Baselines must be accurately set and data-driven. 
• Emissions impacts of a project must be correctly calculated against its baseline. 

Reduction, removal, and avoidance projects involve very different activities and, for some types of projects, it may be more challenging to establish an accurate baseline. However, without accurate baselines, climate impacts cannot be reliably determined.

Across the voluntary carbon market, Reduction credits represent roughly 20% of the purchases. Removal credits represent roughly 5% of the purchases. The remainder, roughly 75%, are avoidance credits.

Carbon Reduction Credits

Carbon reduction must drive the majority of our push to net zero, but translating carbon reduction activities into carbon credits that can be purchased is challenging. Examples of activities represented by carbon reduction credits include reducing fossil fuel use by improving fuel efficiency, or programs that reduce the methane that is generated from farms or municipal waste processing. 

Reduction credits are measured and quantified against the baseline emissions of an existing technology or process. Some reduction credits are easy to track and measure, such as efficiency investments or destruction of fugitive methane. Other projects are more complex. For example, low-emission cookstove projects in developing regions rely on tracking patterns of cookstove use and quantifying emission factors for various fuel and stove combinations, both of which are hard to do. The result, as studies have shown, sometimes leads to overcrediting in reduction projects. 

Superpollutant Credits

One class of reduction credit, superpollutant credits, has garnered recent attention. These credits involve the reduction of non-CO2 greenhouse gases with very strong radiative forcing, such as methane, nitrous oxides, or fluorinated gases like chlorofluorocarbons. These are not a substitute for CO2 removal, but can provide rapid and profound reductions at modest cost. Many different kinds of superpollutants exist in today’s market, worth roughly $60M today. Recent purchases by tech companies and others have highlighted the potential of these reduction credits.

Another class of reduction credit, transition credits, involves the deliberate early closure of emitting assets like coal-fired power plants or heavy manufacturing facilities. Early efforts by governments, banks, and companies around the world under the Just Energy Transition Partnership agreement jump-started transition credits as a concept at COP26. The Kinetic Coalition, in partnership with many groups including Relae, has launched work to bring transition credits to market with several pilot efforts, including closing a coal plant in the Philippines 10 years early. 

Carbon Removal Credits

Projects that remove carbon come from a diverse set of solutions, from nature-based solutions like reforestation, to hybrid solutions like biochar, to engineered solutions such as direct air capture and storage. Roughly 5–6% of credits on the voluntary carbon market today are classified as removals, up from roughly 3% a few years ago.

Carbon removal baselines are determined differently depending on whether a project uses an engineered, hybrid, or nature-based solution. For engineered removals, the baseline is zero, because no carbon removal was occurring in the absence of the project. The credited removal will be the difference between the quantity of carbon removed and any emissions that occur to facilitate the removal (determined through a carbon credit life cycle assessment). Baselines for hybrid and nature-based removals can be more challenging. In natural systems, changes in carbon stocks created by removals must be measured and approximated over time, and creditable removals represent the additional carbon removed by the intervention relative to the baseline (e.g., fallow land versus a reforestation project).

Another important consideration for carbon removal credits is project durability, a measure of the likely duration of carbon storage. Stored carbon can re-enter the atmosphere either through deliberate actions (e.g., deforestation) or accidental ones (e.g., wildfires). Nature-based removals are especially vulnerable to being re-released and are usually considered less durable (i.e., stored for less than 50 years). In contrast, engineered solutions offer high durability (i.e., stored for hundreds to thousands of years), and hybrid removals also offer durability periods that are typically longer than those of nature-based removals.

While less durable, nature-based solutions are effective, cost-effective, and widely available today. They made up over 95% of all carbon removal credits issued in 2025. Engineered and hybrid solutions are more expensive and scarce but offer longer durability. Prices of engineered carbon removal are likely to fall with innovation and increased market participation, but are currently much higher than most nature-based credits. With SBTi's finalized Corporate Net-Zero Standard V2.0, this balance is likely to shift. Large companies must now purchase removal credits covering 1–100% of scope 1, scope 2, and scope 3 emissions between 2035 and their net-zero year, with an explicit focus on more durable CO2 removal credits.

Carbon Avoidance Credits

Examples of carbon avoidance include avoiding deforestation that would result in the release of carbon dioxide into the atmosphere or clean energy projects that avoid the release of emissions from burning fossil fuels in possible facilities. This can be confusing, since many avoided credits are called reduction credits, as is the case with projects under the Reducing Emissions from Deforestation and Forest Degradation (REDD+) framework. Avoidance credits make up roughly 75% of certified credits on the voluntary carbon market today - an overwhelming majority - in part due to high availability and low price. 

Avoiding emissions is an important goal with numerous environmental, climate, community, and other benefits. Relae works with clients and customers across industries on developing and implementing strategies to avoid emissions within their value chain. However, there are significant challenges with the way that many carbon avoidance credits are created.

• Carbon avoidance credits are based on an estimate of the emissions that might have existed had a project not been funded. Because it is impossible to observe what might have happened in the absence of a project, carbon avoidance estimates are determined by considering historic data and contextual information. Statistical models can be used to create a presumed baseline that represents what would have happened in the absence of the project.

• Because the baseline is not observed in an avoided emissions project, there is uncertainty in calculating the number of carbon credits it produces. If the baseline is not set accurately, a project can overcredit. While the lack of a directly observed and measured baseline means avoidance credits will always have some degree of uncertainty, high-quality avoidance projects present compelling evidence to support their baselines, greatly reducing uncertainty. 

New datasets, statistical techniques, and methodologies are providing opportunities for developing avoidance credits with more certainty. Three REDD+ methodologies have now cleared the Integrity Council for the Voluntary Carbon Market (ICVCM) assessment for its Core Carbon Principles (CCPs), a concrete sign that credit quality standards for avoidance projects are maturing.

Defining and Standardizing Quality in the Voluntary Carbon Market

Carbon credits are intended to reduce, remove, or avoid emissions. They pay for an environmental service that must be delivered. Companies working to generate climate benefits through credit purchases must grapple with the differences and uncertainties of credit quality to ensure that the intended benefits are realized. 

While high-quality credits exist for all types of projects, a rich understanding of the differences in methodologies, geographies, physics, and ecology is required to identify high-quality projects and understand varied certainty, durability, and risk terms. Identifying high-quality carbon projects demands extensive and project-specific diligence beyond carbon market certification.

Our own diligence work reveals that high-quality projects can be hard to find. Fewer than 10% of the carbon removal projects we assessed for our 2026 State of the Voluntary Carbon Market report met our quality criteria. This diligence work now has an additional, independent backstop. As of August 2026, the ICVCM has approved 44 methodologies across 13 programs, as eligible for its CCP label, including ACR, Gold Standard, and VCS. For buyers, considering projects that are CCP-eligible should be used as a first filter—not a substitute for project-level diligence, but representing a legitimate floor.

While realized emissions impacts may be difficult to prove in some cases, it is important to remember that some projects provide additional co-benefits. REDD+ projects, for example, may have a positive impact on conservation and biodiversity, and cookstove projects may offer clear human health and social welfare benefits. However, these benefits should be assessed separately from carbon reduction, removal, or avoidance benefits.

Frequently Asked Questions

What's the difference between a carbon credit and a carbon offset? 

A carbon credit represents one verified tonne of emissions reduced, removed, or avoided. A  carbon offset describes how a buyer uses that credit, typically to counterbalance emissions it has not yet accounted for. The credit itself does not change type based on how it's claimed.

Which type of carbon credit—reduction, removal, or avoidance—is highest quality? 

No single type is inherently highest quality. Each project, regardless of type, is verified against a defined baseline. Quality depends on how rigorously that specific baseline was set and how well the project meets other quality criteria. Removal credits from engineered sources have the most straightforward baseline (zero), and avoidance credits carry the most baseline uncertainty by design, but these are only one determinant of credit quality.

Do carbon removal credits automatically meet the ICVCM’s Core Carbon Principles? 

No. The ICVCM assesses methodologies and programs, not individual projects. If a project uses a methodology that is eligible for the CCP label, this can be a useful floor but is not a guarantee of high quality.

How does SBTi's near-term removal mandate change which credits I should buy now?

SBTi's finalized Corporate Net-Zero Standard V2.0 doesn't require removal purchases until 2035, but it sets the ramp now (i.e., 1% of scope 1, scope 2, and scope 3 emissions in 2035, scaling to 100% by the net-zero year). This means the highest-durability removal supply that is scarcest and most in demand today is the same supply that many companies will need later. The SBTi guidelines are still changing, so buyers and project developers must track them closely.

Key Takeaways

• Relae (formerly Carbon Direct) has conducted over 900 comprehensive, rigorous reviews of carbon removal (CDR) projects around the world. But fewer than 10% meet our standard for high-quality. In today’s market, scientifically-credible CDR supply is scarce.
• To identify high-quality projects, buyers and investors previously had to commission numerous deep diligences, which often made it a lengthy and complex process, not well-suited to most market participants. 
• The Diligence Collection changes that paradigm by giving you direct access to existing comprehensive analysis on a curated set of high-quality CDR projects. The hard work of identifying high-quality projects is already done, allowing you to move faster, spend less, and procure with more confidence.

Relae Sets the Bar for High-Quality CDR

Since 2020, every year Relae has released an updated version of the Criteria for High-Quality Carbon Dioxide Removal in collaboration with Microsoft. The Criteria set the standard for scientific rigor across nine CDR pathways and across six technical dimensions. Using this standard, the Relae team has conducted diligence on over 900 CDR projects across 63 countries. Our diligence has been used for over 50% of all tonnes contracted through announced CDR offtake agreements worldwide, including diligence for the majority  of tonnes from Microsoft’s announced offtakes. This gives Relae a uniquely deep understanding of the CDR market; and importantly, it has highlighted that high-quality projects in the voluntary carbon market are scarce. 

Quality Is the Central Challenge in CDR Procurement 

Only 10% of the projects that Relae has assessed meet our high-quality criteria. This means that without rigorous, scientific assessment, buyers and investors run real risk of exposing themselves to delivery shortfalls, financial loss, and reputational damage. 

This presents a series of challenges to buyers and investors interested in procuring or investing in CDR. Conducting diligence on CDR projects is time-intensive, complex, and requires deep expertise. Building the internal capacity to rigorously evaluate a wide variety of CDR projects isn’t practical for most actors. But conducting the in-depth diligence required to procure or invest confidently requires real commitment, especially when a significant proportion of the projects diligenced may not be high-quality. Finding the needle in the CDR haystack isn’t easy.

The Case for Curated CDR 

The Diligence Collection directly addresses these challenges by providing self-serve access to diligence on a curated set of high-quality CDR projects vetted by Relae. Every project has already been evaluated against the Criteria for High-Quality Carbon Dioxide Removal, the science-based benchmark jointly established by Relae in collaboration with Microsoft. The Collection includes projects reviewed on behalf of Microsoft and other major buyers, and more broadly reflects our diligence work across the market.

With the Diligence Collection, you're not starting from scratch. Instead, you're starting from a shortlist of some of the highest-quality CDR opportunities available, with robust scientific diligence to back them up. The bottleneck that's slowed procurement for so many organizations is no longer a concern.

The Collection offers two levels of diligence, matched to the level of scrutiny your commitment warrants:

1. Desk review: An executive-level assessment using available project documentation, enough to make an informed shortlisting decision or purchase.
2. Deep diligence: A comprehensive technical evaluation covering project design, operational risk, technology assessment, policy landscape, and community impacts, reflecting the same methodology that's informed the procurement programs of Microsoft and other major buyers.

Both tiers include the option to commission an updated evaluation as your needs evolve.

What Rigorous CDR Diligence Involves 

The depth of Relae’s diligence sets the Diligence Collection apart. Our desk review process involves conducting detailed assessments to evaluate projects against 6 quality principles: social harms, benefits, and environmental justice; environmental harms and benefits; additionality and baselines; measurement, monitoring, reporting, and verification; durability; and leakage. The result is a comprehensive report that assesses projects against these criteria, highlighting the project's overall quality, strengths, and weaknesses in a clear, succinct way that supports decision-making. 

Many of our reports dig even deeper. Our deep diligences assess both a project’s quality and its delivery risk. To evaluate delivery risk, we assess projects across 5 elements: technologic, economic, commercial, operational, and political. Deep diligence is conducted over 3-4 months, which includes weekly back-and-forth with the supplier and a site visit to understand all of the nuances of the project and validate developer claims on the ground. The resulting report not only documents a project's strengths and weaknesses, but also outlines risk mitigation measures and recommends improvements over time. 

Broader Access, Stronger Market 

Forward offtake demand in the CDR market has historically concentrated among a handful of large buyers, and as our 2026 State of the Voluntary Carbon Market report notes, diversifying that pool is essential to enabling the next generation of CDR supply. The Diligence Collection is built to support exactly that. By making the scientific rigor behind the world's largest CDR transactions available through a self-service platform, it opens credible procurement to organizations at any stage of purchasing. More buyers accessing high-quality, de-risked projects means more capital flowing to suppliers, more projects able to scale, and a more resilient market that doesn't depend on a small number of actors to function.

High-quality CDR supply is scarce, and the best projects are in high demand. The Diligence Collection gives you the foundation to act efficiently and with confidence, without starting from zero.

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Frequently Asked Questions

Who Can Access the Relae Diligence Collection?

The Diligence Collection is available to approved subscribers, including CDR buyers and investors seeking to more efficiently evaluate carbon removal projects. To preserve the independence and integrity of the Collection and protect proprietary diligence insights, access is not available to project developers or rating agencies.

How Is the Relae Diligence Collection Different From a Rating Agency or Market Intelligence Platform?

Most rating platforms optimize for quantity; we optimize for quality. Our process includes pathway-specific risk assessments and, in many cases, site visits from our in-house scientists, engineers, and technical experts—the same multidisciplinary team and judgment behind our own portfolio decisions and the procurement programs we support directly. The Collection also includes projects diligenced before they've received external ratings, giving you visibility into promising opportunities at the pre-commercialization stage.

Does Inclusion in the Relae Diligence Collection Mean Relae Endorses a Project?

Inclusion means a project was evaluated through our scientific diligence process and, at the time of review, met our Criteria for High-Quality Carbon Dioxide Removal. It reflects a positive diligence outcome based on the information available during the review and the project's stage of development at that time. As projects and market conditions evolve, we recommend considering whether updated diligence or additional evaluation is appropriate for your specific procurement or investment objectives.

Can I Request Diligence on a Project That Isn't Already in the Collection?

Yes. You can commission us to diligence a specific project based on your procurement or investment priorities. Whether it's later added to the Diligence Collection depends on a few factors beyond just meeting our quality bar, including consent from you as the commissioning buyer and approval from the project developer.