Carbon Removal, Reduction, and Avoidance Credits Explained

Key Takeaways

• CORSIA, the program intended to address international aviation emissions, is currently the world’s largest international compliance carbon market, with approximately 200 million tonnes of eligible emissions units (EEUs) expected to be retired for Phase 1 (2024-2026) compliance. 
• Airlines have already begun retiring significant volumes of credits (clean cookstoves and jurisdictional REDD+) toward their Phase 1 obligations ahead of the January 2028 compliance deadline, signaling that the industry is treating CORSIA as a binding policy mandate.
• In addition to the four already approved, a record 25 carbon standards have applied for eligibility to supply credits under Phase 2 (2027–2035), pointing to a diversifying pipeline of credits.
• Legal enforcement of CORSIA at the national level remains uneven. A handful of jurisdictions, including the EU, Japan, Brazil, New Zealand, and Canada, have established compliance regimes, but it is unclear whether other major aviation markets will implement domestic enforcement requirements by 2027.
• As CORSIA matures alongside other compliance and voluntary frameworks, strategic engagement increasingly depends on understanding where eligibility overlaps and where the most value can be found.

Introduction to CORSIA 

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) was established and is managed by the International Civil Aviation Organization (ICAO)—a specialized agency of the UN—and provides a compliance mechanism to reduce emissions from international aviation that do not fall within a single country’s contributions to the Paris Agreement. For years, CORSIA generated more commentary than activity—airlines weren’t required to offset a single tonne of CO₂ emissions (tCO₂) during the pilot phase (2021–2023). That is changing; in early 2026, Singapore Airlines and Japan Airlines retired significant volumes of carbon credits against their Phase 1 (2024–2026) obligations. Increasing authorization announcements showcase the eligible supply steadily entering the market, and 25 carbon standards have applied for Phase 2 (2027–2035) eligibility. As CORSIA becomes an active compliance market, this article explains how the program works, what is driving the current trends, and what to watch as Phase 1 draws to a close.

Who is Covered by CORSIA Phase 1 and Phase 2?

Because emissions from international aviation are not tied to any individual nation, the International Civil Aviation Organization (ICAO) adopted CORSIA in 2016 to complement the Paris Agreement framework and address these emissions. CORSIA applies to international airlines operating flights registered between participating countries. 

• During Phase 1, offsetting obligations apply only to routes between the 130 countries that have voluntarily opted in. 
• From Phase 2, participation becomes mandatory for all 193 ICAO member states, except for those below the aviation activity threshold or classified as Least Developed Countries, Small Island Developing States,  or Landlocked Developing Countries—although they can voluntarily participate. 

Several major aviation markets, including China, that are not participating in Phase 1 will be required to do so from 2027. 

Offsetting Obligations

Airlines are required to offset the portion of their emissions that exceeds the program’s baseline on routes subject to offsetting. The key input is the annual Sectoral Growth Factor (SGF), which reflects how much annual emissions on covered routes have grown above the baseline (set at 85% of 2019 emissions). In simple terms, each airline's offsetting obligation is calculated by multiplying its CORSIA-regulated emissions by the SGF.

For example, an airline that emits 1 million tCO₂ on covered routes in a year when the SGF is 10%, would have an offsetting obligation of 100,000 tCO₂. An airline that emits 500,000 tCO₂ in the same year would have an obligation of 50,000 tCO₂. The actual 2024 SGF was 15.4%, exceeding the baseline and triggering offsetting obligations for the first time since the COVID-induced reduction in international aviation activity. 

Beginning in 2033, CORSIA’s offsetting formula combined the SGF with an individual component that accounts for each airline's own emissions growth. The individual weighting starts at 15% in 2033 (with an SGF weighting of 85%) and rises to 45% by 2035 (SGF 55%). This progressively ties each airline’s obligations to its own emissions trajectory rather than sector-wide trends alone.

Airlines can also reduce their obligations by reporting the use of CORSIA Eligible Fuel (CEF). In order to qualify as CEF, Sustainable Aviation Fuel (SAF) must meet ICAO’s certification criteria. Offsetting remains a lower-cost option than sustainable fuel procurement, and CORSIA obligations are currently not influential drivers of CEF/SAF uptake compared to supply mandates, such as ReFuelEU Aviation. However, these dynamics will evolve as CORSIA matures and SAF prices continue to fall. 

CORSIA Eligible Carbon Credits: Phase 1 and Phase 2 

To determine the eligibility of carbon crediting standards and credits issued under those standards, ICAO's Technical Advisory Body (TAB) reviews applications and recommends approval to the ICAO Council, subject to restrictions on methodologies, vintages, and more granular project elements. Currently, no standard is approved without exclusions. Credits eligible for use under CORSIA are known as Eligible Emissions Units (EEUs).

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TAB broadly excludes some project types across standards, including large-scale grid-connected renewable energy projects and most project-level REDD+ activities. The exclusions reflect TAB's assessments of baselines, safeguards, and quantification gaps. However, these assessments are not static; ICAO updates its determinations as the evidence base improves. For example, in 2025, TAB approved certain direct air capture (DAC) and biochar pathways for the first time.

A record 25 carbon standards—certifying projects from emissions avoidance to engineered carbon dioxide removal (CDR)—have applied for Phase 2 eligibility in the 2026 assessment cycle, reflecting the scale of the opportunity. The International Air Transportation Association (IATA) projected a demand of 170–236 million EEUs for Phase 1 alone; developers are eager to serve this growing market. Assessment results are expected in October 2026.

Article 6 and Corresponding Adjustments

The biggest bottleneck for eligible supply has been requirements relating to Article 6.2 of the Paris Agreement. CORSIA requires that EEUs carry a host country Letter of Authorization (LoA) confirming that the host country will not count the underlying mitigation toward its Nationally Determined Contribution (NDC). This prevents double counting between CORSIA and national emission inventories, but it also means eligible supply depends on host country authorization, not just meeting methodological requirements. Authorized credits are called Internationally Transferred Mitigation Outcomes (ITMOs). 

To manage the risk that a host country fails to apply the promised corresponding adjustment, projects must secure legally enforceable insurance policies that either provide replacement EEUs or funds to secure them. Several providers have been approved to insure EEUs registered by Gold Standard and Verra. 

Insurance requirements do not apply when the host country has already confirmed the corresponding adjustments in its mandatory Paris Agreement reporting. For example, in March 2026, Madagascar submitted a Biennial Transparency Report (BTR) and annual information report that reflect the application of corresponding adjustments to CORSIA-eligible clean cookstoves credits listed on the Verra registry. According to Verra, BTR accounting is the “highest level of assurance” that ITMOs will not be double counted. 

The Enforcement Challenge

With the authorization bottleneck loosening, market attention is turning to demand. Critically, ICAO has no direct enforcement power; for CORSIA to work, participating countries must pass laws requiring airlines to comply with its requirements. Under CORSIA rules, airlines must retire their Phase 1 EEUs by January 2028, but most are not yet subject to legal sanctions for failing to comply. Where regulations do exist, it remains unclear whether penalties will be stringent enough to matter, or whether they will be enforced at all.

Where legal enforcement of offsetting requirements does exist, it varies by design. For example, in Brazil, failure to comply attracts a penalty of BRL 50/tCO₂ (US$10/tCO₂) and an administrative fine. Meanwhile, the Canadian Aviation Regulations impose administrative fines capped at CAD 25,000 (US$18,000) per infraction, but there is no specific fine for each tCO₂ not offset. However, the absence of a statutory penalty framework does not necessarily mean compliance will not be enforced. For example, New Zealand manages CORSIA participation through an administrative Memorandum of Understanding with Air New Zealand, rather than a dedicated legal regime (though this will change from 2027). Similar informal arrangements may be more common than the legislative record suggests.

According to 2024 data, US-based airlines account for around 15% of CORSIA-covered emissions. However, there is no indication that the federal government will implement CORSIA penalties under the current administration. It is unclear how non-compliance by a major economy will impact market confidence or enforcement by other governments, but uncertainty about US participation in multilateral climate programs is not new. 

What to Watch

• Global enforcement: As Phase 2 approaches, the prospects for CORSIA enforcement in key aviation markets will become clearer. China, which has not participated in the voluntary phase and has raised objections to CORSIA’s design on grounds of fairness, presents an uncertain picture for domestic transposition. The UK government has consulted on a draft legal amendment that would penalise non-compliance for UK airlines at £100/tCO₂ (US$130/tCO₂), but has not published updates since February 2025. 

• EU Emissions Trading Scheme (ETS) update: In July 2026, the European Commission proposed to expand the ETS to address emissions from flights departing the European Economic Area (EEA) to destinations within 5,000 km. To avoid double charging emissions also regulated under CORSIA, the Commission proposed to deduct CORSIA costs from airlines’ ETS obligations. While the Commission flagged concern about the stringency of CORSIA eligibility criteria, the proposed rules would not impact demand for Phase 1 EEUs. Still, it is worth watching for future restrictions on which credits EU airlines can use for CORSIA, whether in Phase 1 or 2. 

• Supply financing vehicles: The LEAF Coalition—which purchases credits verified under the CORSIA-eligible ART TREES standard—has signed over US$1.5 billion worth of purchase agreements with host countries. The Forest Carbon Partnership Facility (FCPF) and BioCarbon Fund Initiative for Sustainable Forest Landscapes (ISFL), both CORSIA-approved for Phase 1 in early 2026, have built jurisdictional REDD+ pipelines across dozens of countries. As projects mature, it will be worth watching how issued credits are marketed across compliance and voluntary channels.

Strategic Considerations

Avoided emissions credits dominate early CORSIA supply—and consequently demand—principally from avoided deforestation and clean cooking projects. As there is no regulatory premium for higher-cost CDR, this is not surprising. But as the market matures and supply diversifies, airlines are likely to begin differentiating on geography, co-benefits, and environmental performance. Corporate interest is growing in projects that abate non-CO₂ superpollutants, due to their outsized near-term climate impact. As many of these projects are based in countries actively issuing LoAs, this may soon translate into a supply of superpollutant EEUs. Some airlines are reluctant to procure aggressively now, anticipating the upcoming availability of higher-quality credits.

Credits that hold value across multiple frameworks could carry a strategic premium. A credit also eligible for Singapore's carbon tax, Switzerland's CO₂ Act, or SBTi claims may offer more durable demand than one tied to a single use case. While specific requirements vary significantly, we are beginning to see convergence around broad principles, such as the need for Article 6 authorization for credits used in compliance markets tied to NDCs. Procurement and project development strategies could begin to favour credits that confer wider market optionality. 

The precondition for all of this is policy stability. Longer-term offtake agreements, portfolio strategies, and meaningful investment in project development depend on confidence that CORSIA rules will hold. Efforts to soften emissions regulations in response to energy price shocks are now testing this confidence, from proposed changes to soften the EU ETS to Singapore's deferral of its SAF levy. Tracking price signals, enforcement developments, and authorization trends will be essential for identifying firm demand and where the opportunities lie.

Conclusion

Effective engagement with CORSIA requires more than developing quality projects. It means understanding methodological eligibility requirements, navigating Article 6.2 authorization processes, tracking a network of overlapping national regulations, and staying ahead of a rapidly evolving market landscape. Relae (formerly Carbon Direct) brings together policy, market, and scientific expertise to help clients on all of these fronts.

Frequently Asked Questions

Which carbon credits can airlines use for CORSIA compliance?

CORSIA Eligible Emissions Units (EEUs) must be issued by crediting standards approved by ICAO's Technical Advisory Body. Every approved standard currently has exclusions on certain methodologies and project types, so eligibility is granular rather than blanket. EEUs must also have a host country Letter of Authorization confirming a corresponding adjustment under Article 6.2 of the Paris Agreement.

Is CORSIA actually enforceable?

In all phases, CORSIA obligations are legally binding when a country writes them into domestic law. Countries participating in Phase 1 are expected to do this, but not all have, and enforcement remains uncertain in several key aviation markets (e.g., the United States). Even where enforcement exists, penalty regimes vary significantly in stringency and design. 

How does the July 2026 EU ETS proposal affect CORSIA?

The European Commission's proposal to expand ETS coverage to more flights does not reduce demand for CORSIA credits. While it would lead to overlap between flights covered under CORSIA and the ETS, as proposed, airlines could have CORSIA costs effectively deducted from their ETS allowance obligations. However, the Commission has signalled continued scrutiny of CORSIA's effectiveness, which could shape future limits on the credits EU airlines are allowed to use.

Key Takeaways

• Sustainable aviation fuel (SAF) will not reach price parity with fossil jet fuel under any realistic near-term scenario. The cost premium is structural—rooted in the chemistry of feedstocks—not a temporary artifact of early-stage markets.
• Neither airlines nor corporate buyers are purchasing SAF for its energy content. Both are buying sustainability claims: airlines for regulatory compliance and scope 1 credentials, corporates for scope 3 emissions reporting and social license to operate. The fuel is incidental to both transactions.
• Corporate offtakes can play a genuine role in building the SAF industry, but only if they create capacity that would not otherwise exist. Additionality is not a technicality; it is the entire value proposition.
• High-integrity SAF procurement requires evaluating not just carbon reduction, but feedstock sourcing, leakage, and social and environmental harms. The newly released Criteria for High-Quality Low Carbon Fuels from Relae (formerly Carbon Direct) provides a framework for doing this rigorously.

A Major Deal Illustrates How the SAF Market Really Works 

On June 5, 2026, Google and American Airlines announced a three-year agreement under which Google will purchase sustainable aviation fuel (SAF) certificates (SAFc) associated with 35 million gallons of SAF. American will take physical delivery of the fuel at Chicago O'Hare. Google receives the emissions attributes. The arrangement relies on book-and-claim accounting, in which the physical fuel and the environmental attribute are legally separated and transferred to different parties.

The deal is a window into how the SAF market works, and what every company in the value chain needs to understand before entering it.

The SAF Cost Premium Is Structural, Not a Market Inefficiency

There is a persistent hope in the aviation industry that SAF will eventually reach price parity with fossil jet fuel. This will not happen, at least not through any mechanism that currently exists or is credibly in development.

The economics are the product of thermodynamics. Petroleum is pre-deoxygenated; over millions of years, heat and pressure stripped oxygen from biological material, concentrating energy into the hydrocarbons we pump out of the ground today. Bio-based SAF feedstocks, e.g., vegetable oils, agricultural residues, and other biomass, are oxygen-rich (carbohydrates, not hydrocarbons). Power-to-liquid e-fuels start from captured CO₂, which is fully oxidized. 

Either way, every SAF production pathway must pay an energy debt to remove or chemically reduce that oxygen, in the form of hydrogen deoxygenation, energy inputs, and processing costs. This is not a manufacturing inefficiency that scale will solve. It is a constraint baked into the feedstocks themselves.

The numbers reflect this. According to the European Union Aviation Safety Agency (EASA), the average market price of SAF in 2025 was approximately €1,925 per tonne, roughly three times the €640 per tonne average for conventional jet fuel. 

The cheapest pathway, hydroprocessed esters and fatty acids (HEFA), produced from waste oils like used cooking oil or tallow, represents almost all current SAF supply and sits at the lower end of the SAF cost range. Costlier cellulosic and e-fuel pathways push it higher. EASA estimates 2025 production costs for power-to-liquid e-fuels at €7,520 per tonne, more than ten times the cost of conventional kerosene. While these costs can and will come down, none are expected to approach price parity.

The feedstock ceiling compounds this. HEFA from waste oils is the cheapest SAF pathway, but waste oil supply is finite and competes with renewable diesel, which typically offers better margins for producers. As mandates push SAF volumes beyond what HEFA can supply, the industry must move to cellulosic biomass or power-to-liquid pathways, at progressively higher cost. Scaling the SAF industry does not automatically bring prices down. In the near term, it pushes them up.

Policy Determines Who Absorbs the Cost

If price parity is not coming, the cost premium lands somewhere. Two policy philosophies have emerged to answer that question.

Europe has largely adopted the polluter-pays principle: SAF mandates place the cost burden on fuel suppliers and, by extension, on airlines and their passengers. The EU's ReFuelEU Aviation regulation and the UK's SAF mandate both carry steep penalties for non-compliance. As Relae has documented, in the UK, those penalties range from three to 13 times the cost of compliance, depending on the obligation type and year, signaling that regulators are serious about pushing aviation toward sustainable fuels.

The United States approached the problem differently, leaning on taxpayer subsidies.The Inflation Reduction Act (IRA) 45Z Clean Fuel Production Credit and its predecessor, the 40B Sustainable Aviation Fuel Credit sought to socialize much of the cost premium. The appeal of this approach was that it made SAF economics viable without raising ticket prices. Its vulnerability was political: when the IRA's incentive landscape was revised, the project pipelines that had formed around those credits evaporated quickly. US taxpayer-funded support proved politically less durable than the UK and EU’s mandated compliance obligations.

Neither model works in isolation. Mandates without bankable project finance generate demand signals but no new supply. Incentives without policy durability attract project interest but cannot get facilities to final investment decisions. The deals that have actually moved capital combine a stable policy floor, whether mandate or incentive, with long-term private commitments that provide the revenue certainty project finance requires.

The Google-American Airlines deal illustrates the incentives-plus-private-commitment structure. The deal explicitly credits the Illinois SAF tax credit as the enabling policy lever. HEFA SAF of this type is eligible to generate Renewable Fuel Standard credits (RINs), and fuel produced from 2025 onward qualifies for the IRA's 45Z Clean Fuel Production Credit. This stack provides additional floor economics. The corporate offtake completes the structure by delivering the revenue certainty that volatile policy credits alone cannot. Remove any one of those elements and the deal's economics likely do not hold.

Nobody in this Market Is Buying SAF for its Energy Content

This is the key to understanding how the SAF market works. Neither airlines nor corporate buyers purchase SAF for its energy content. Airports have kerosene. Airlines do not need SAF to keep planes in the air. Corporate buyers, like Google, have minimal operational use for aviation fuel at all. While recent global disruptions in crude oil supply have highlighted SAF in the context of energy security, the industry as it exists today does not represent a realistic hedge against conventional fuel volatility.

What all parties are buying is the sustainability attribute attached to the fuel. For airlines, the relevant claim is a scope 1 emissions reduction: the right to report lower lifecycle carbon intensity for their flight operations. For corporate buyers, the relevant claim is a scope 3 reduction, a documented abatement of the emissions associated with their employees' business travel. Book-and-claim accounting makes this architecture explicit: it legally severs the physical fuel from the environmental attribute, allowing each to be transferred to the party that values it. The fuel is the delivery mechanism for the claim. 

This distinction matters for assessing the market. Airlines operate on among the lowest margins of any major industry. They cannot absorb the cost premium voluntarily without fundamentally compromising their finances. They participate in SAF markets when required to by mandate, or when a corporate partner subsidizes the premium by purchasing certificates downstream. The cost premium does not disappear; it shifts. Understanding where it lands is the starting point for any serious procurement decision. 

Corporate climate programs have finite budgets. SAF competes with renewable electricity procurement, fleet electrification, CO₂ removal, and supply chain decarbonization for the same dollars. Buyers who want their sustainability claims to match the actual sources of their emissions (rather than offsetting aviation with unrelated activities elsewhere) have a genuine reason to prefer SAF. 

A SAF Claim Is Only as Strong as the Quality Behind it

SAF buyers and sellers trade sustainability claims. The quality of those claims is the entire value proposition, and the reputational liability travels with them. The companies with the greatest willingness to pay for SAF certificates tend to be those with the most brand exposure: high-profile technology companies, professional services firms, and financial institutions. These are also the companies most likely to face scrutiny from regulators, NGOs, and investors if a claim does not hold up. Buying a certificate does not protect a company from that scrutiny. It transfers the liability along with the attribute.

That means a rigorous buyer needs to answer at least three distinct questions before relying on a SAF claim.

1. Does this fuel actually reduce lifecycle emissions? 

SAF's climate case rests on a carbon cycle argument: the feedstock absorbs CO₂ from the atmosphere as it grows, so when that carbon is released during combustion, the net addition to the atmosphere is theoretically near zero. But that logic holds only if upstream production is clean, and it often is not. 

Indirect land use change (when demand for a feedstock crop displaces food agriculture elsewhere, triggering clearing of forests or grasslands) can generate substantial emissions elsewhere in the global land and food system, eroding or eliminating the lifecycle benefit. Even waste-based feedstocks are not automatically clean: used cooking oil and tallow have existing market uses, and diverting them without careful accounting can displace those uses, alter commodity markets, and create emissions leakage elsewhere. 

2. Is the purchase additional? 

Additionality asks whether the procurement caused SAF to exist that otherwise would not have. This is a harder question than it appears, especially in markets where multiple policy support mechanisms are already active. For the Google-American Airlines deal, one critical variable for financial additionality—the SAFc price—has not been disclosed. If Illinois credits and federal RINs already cover most of the HEFA cost premium, then the question of what Google's purchase actually caused to happen is genuinely open. However, American Airlines has stated publicly that the long-term nature of the agreement enabled them to secure a new SAF offtake with Valero Marketing and Supply Company. The supply arrangement that may not have been bankable on the basis of volatile RIN markets and changeable policy alone. That is a real additionality argument. But it requires transparency to evaluate. The undisclosed SAF credit price is a current market liability, not just in this deal, but across the voluntary SAF market broadly.

Long-term offtakes do something that policy credits cannot: they provide stable, bankable revenue certainty. RIN prices fluctuate. Tax credits change with administrations. Neither can reliably anchor a final investment decision at the project level. A multi-year, creditworthy offtake agreement can. This is the distinctive and genuinely valuable role that corporate buyers play in this market: not paying the cost premium per gallon, but reducing the financial risk premium that keeps capital on the sidelines.

3. Is the full supply chain sound? 

Carbon claims are not the only dimension of sustainability that matters to a buyer's reputation. Companies making claims about their SAF procurement are implicitly making claims about their supply chains. That means labor practices, community impacts, Indigenous rights, feedstock sourcing integrity, and market leakage from displaced uses all fall within the scope of what a rigorous buyer should evaluate. A SAF supply chain that displaces food crops, harms a proximate community, or causes deforestation through indirect land use change creates a reputational problem that no certificate can fix.

What High-Integrity SAF Procurement Looks Like

The voluntary SAF market is still early, and the transparency it requires does not yet exist consistently. Relae recently released the Criteria for High-Quality Low Carbon Fuels, a comprehensive, publicly available framework designed to help close that gap. 

The criteria address six principles across the full supply chain: carbon accounting, additionality, feedstock sourcing, leakage, environmental harms, and social harms and environmental justice. They are designed as a practical reference for what a credible SAF claim requires, and where existing certifications may leave gaps that require additional diligence.

At the transaction level, five questions should have clear answers before any buyer signs an offtake:

1. Is the certificate linked to a specific project or supply agreement? 
2. Is that project financially dependent on the offtake, after accounting for all policy support already in the stack? 
3. Is the lifecycle emissions profile documented across the full well-to-wheel boundary, including indirect effects? 
4. Are the feedstock sourcing and supply chain risks assessed and disclosed? 
5. Has the producer evaluated leakage and community impacts?

The Google-American Airlines deal demonstrates what serious voluntary SAF procurement can look like. The Criteria for High-Quality Low Carbon Fuels provides the framework buyers need to evaluate deals like this one rigorously. 

Key Takeaways

• What's happening: The voluntary carbon market (VCM) stalled in 2025, with carbon credit retirements falling 7% despite a 227% surge in corporate climate commitments.
• Why it matters: Over 80% of high-durability carbon removal capacity is at risk of not being realized without additional offtake.
• The implication: For corporate buyers with 2030 climate targets, early movers will define market standards and secure the supply they need, while those who wait risk volatility and constrained access to high-quality credits.

Why the Voluntary Carbon Market Needs Action Now

The voluntary carbon market stands at a crossroads. Credit retirements in 2025 fell far below the billion-tonne-scale projections from earlier in the decade. There is a widening gulf between climate ambition and market action.

The VCM transacts credits that avoid, reduce, or remove emissions. Carbon dioxide removal (CDR), the process of removing and durably storing atmospheric CO₂, remains a small but critical segment, accounting for 5% of credits retired. Limiting overshoot of 1.5°C requires a rapid scale-up of CDR.

However, most organizations with 2030 climate goals have yet to engage in CDR procurement. Without clear market signals today, CDR supply will falter. What's missing isn't capability or knowledge, but the commitment to act. Early movers will define the market in its early stages, while latecomers may face volatility and uncertain supply.

Our latest analysis reveals both troubling trends and clear pathways forward for CDR buyers ready to move from commitment to execution.

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Five Years of Stagnation: The VCM Falls Short of Projections

For five consecutive years, muted growth and persistent oversupply of poor-quality credits have defined the market. In 2025, credit retirements—a proxy for spot-market demand—reached 157 million metric tonnes (Mt), down 7% from 2024.

This incremental growth is far below what market analysts anticipated earlier in the decade, when several projections expected demand to exceed 1 billion tonnes by 2030. 

VCM Credit Trends: Concentrated in Avoidance and Reduction

The VCM has historically been concentrated in avoidance and reduction carbon projects,  largely dominated by REDD+, renewable energy,  and cookstove credits. 2025 marks the first year a new credit type has dominated, though: projects that reduce emissions of superpollutants now make up roughly 20% of all credits issued in the VCM. Superpollutant issuances increased by about 180% between 2020 and 2025, while retirements grew by roughly 150%.

CDR Remains a Small but Critical VCM Segment 

In 2025, CDR credits accounted for only 5% of 2025 retirements, but have a more active forward offtake market—where buyers commit today to purchase credits that will be delivered in the future, providing crucial early-stage financing for projects.

Within the CDR category, high-quality credits are still hard to find. Applying our Criteria for High-Quality Carbon Dioxide Removal, we find that less than 10% of the CDR projects we review meet our high-quality threshold with minimal reservations.

Nature-Based CDR Dominates the Spot Market

Of the all CDR credits issued in the VCM in 2025, 95% originated from nature-based CDR pathways, while 5% represented high-durability CDR pathways such as biochar or bioenergy with carbon capture and storage (BECCS). This distribution reflects the mature role that nature-based CDR projects continue to play in the market, alongside the early stage of durable CDR deployment.

Within nature-based credits, supply and demand dynamics differed significantly between afforestation, reforestation, and revegetation (ARR) and improved forest management (IFM). 

• For ARR credits, issuances and retirements have tracked closely at a roughly 1:1 ratio, with issuances remaining flat at around 7–8 Mt annually over the past four years, leaving little inventory available for spot purchasing. 
• IFM credits, by contrast, have grown 2.5-fold since 2023, making them one of the largest sources of growth within nature-based credits, though high-quality CDR credits from IFM are in much lower supply.

For buyers, this means ARR credits are increasingly difficult to source on the spot market, while IFM credits are more readily available—though careful diligence is needed to identify high-quality projects.

Nature-based offtakes and commitments have expanded in recent years, with more than 90 Mt of future delivery now contracted or committed. The vast majority of these commitments are concentrated in ARR projects, highlighting both the supply constraints facing ARR today and buyers' foresight in securing the supply they will need in the near future.

High-Durability CDR Is Almost Entirely Forward-Looking

The spot market for high-durability CDR credits represents only 0.3% of activity in the VCM, but important dynamics are beginning to emerge as more high-durability CDR technologies reach the market.

From 2021 to 2025, roughly 80% of high-durability issuances and retirements came from biochar and geologic storage. However, the emergence of large-scale geologic CDR projects is beginning to shift the balance, with individual projects capable of delivering hundreds of thousands of tonnes annually. Early-stage methodologies such as enhanced rock weathering (ERW) and ocean alkalinity enhancement (OAE) issued their first credits in 2025, totaling roughly 12,000 tonnes.

While the spot market for high-durability CDR is growing and diversifying, forward offtake agreements continue to define the landscape. The ratio of high-durability spot retirements to volumes committed through forward offtake is 1:70—meaning for every tonne retired today, 70 tonnes have been committed for future delivery.

Forward Offtake Commitments Are Rising Across CDR Pathways

To date, forward offtake agreements, advanced market commitments (AMC), and large contracted deals with intermediaries cover more than 40 Mt of high-durability CDR, in addition to over 90 Mt of nature-based CDR. These cumulative volumes highlight the increasingly central role of forward purchasing in shaping future supply, particularly for capital-intensive, high-durability pathways. 

However, the success of forward offtake strategies depends critically on careful due diligence. Without a rigorous assessment of technological readiness, project viability, and delivery risks, forward commitments risk financing projects that fail to deliver, undermining both individual investments and broader market confidence.

Market Concentration of Forward Offtake Remains High

A small group of companies continues to drive the majority of forward offtake activity. In 2025, Microsoft remained the clear market leader, accounting for roughly 60% of contracted nature-based CDR offtakes and more than 80% of high-durability offtakes with a named buyer announced to date. Other active buyers—including Google, JPMorgan Chase, Equinor, and Amazon—have expanded their commitments, but overall market concentration remains high.

This concentration reveals both opportunity and risk: while anchor buyers are proving the market model works, broader participation is needed to unlock the full scale of CDR deployment required.

Growing Gap Between Climate Ambition and Market Action

Corporate climate targets anchor most current VCM activity: All of the top-10 buyers in the market today participate based on either self-declared commitments or net-zero commitments aligned with the Science Based Targets initiative (SBTi).

Demand forecasts based on these future commitments project that total CDR demand could reach 46-110 Mt by 2030, a ~6-14x growth from today. Yet, how companies decide to implement their targets will ultimately affect the composition of CDR demand within the VCM.

Rather than relying solely on public commitments, we analyzed the behavior of companies that are actively purchasing CDR today. Should today's top buyers follow through on their stated CDR commitments, CDR demand could reach a minimum of 28 Mt by 2030, with 6.5 Mt of demand for high-durability CDR.

However, the discrepancy between observed demand and target-led scenarios shows a persistent gap between what companies say and what they do. SBTi reported a 227% surge in companies setting both near-term and net-zero targets in the 18 months leading up to mid-2025, while carbon credit retirements in the VCM fell 7% in 2025. 

Shifting from intention to execution will ultimately determine whether the VCM evolves into a durable, functioning marketplace or stalls short of the scale required for credible, net-zero pathways.

Rising Trends of Greenhushing and Anonymity Obscure CDR Demand

In the broader VCM, 55% of tonnes retired on the spot market over the past three years have been anonymous, and that fraction has been increasing. A similar trend is true of high-durability CDR: nearly 40% of all offtake transactions made in 2025 did not disclose the participating buyer. This buyer behaviour could reflect the often-discussed greenhushing phenomenon.

When anonymous actors dominate, it becomes harder to track demand signals, verify corporate progress, and establish clear integrity benchmarks. This opacity creates systemic risk for the entire market.

Market Growth Tipping Points on the Horizon

Several pivotal events on the horizon could mitigate risk and unlock project development, tipping buyers into action after half a decade of limited market growth:

• Voluntary demand: SBTi's  Corporate Net Zero Standard V2.0, published in June 2026, confirms credits still can’t count toward scope 1-3 targets, but introduces a voluntary recognition program starting in 2027 and mandatory removal purchasing for large companies from 2035, starting at 1% of footprint. 
• Compliance demand: The UK's Emissions Trading Scheme (ETS) Authority has already committed to integrating carbon removals into the UK ETS by 2028 via an auction model. This is the first confirmed large-scale compliance pathway for CDR credits, though credit-type eligibility is still being worked out.
• Regulatory support: Publication of Article 6.4 methodologies under the Paris Agreement and loosening of CORSIA credit supply bottlenecks could expand eligible supply and boost buyer confidence.

These tipping points in policies, standards, and market structures are advancing with clear timelines, creating conditions to move CDR procurement from hesitation to activation.

CDR Supply Faces Critical Challenges

While buyer inaction poses one threat to market growth, the supply side faces its own critical challenges.

30%–220% More Investment Is Needed in Nature-Based CDR Supply

Nature-based CDR would require a 30%–220% increase in finance to support current corporate targets. Relae (formerly Carbon Direct) has identified US$18 billion in publicly committed funds for nature-based CDR announced from 2018 to 2025. If deployed immediately to generate high-quality CDR, this level of funding could translate into up to 32 Mt per year by 2030 and 290 Mt cumulatively through 2040.

This is sufficient to meet the conservative 28 Mt demand floor from today's active buyers—but falls well short of what would be needed if even a fraction of companies with 2030 targets begin executing on their stated commitments.

80% of High-Durability CDR Projects Are at Risk

The situation is more acute for high-durability CDR. We estimate that over 80% of the total 2030 credit supply pipeline is at risk, due to insufficient project offtake and financing agreements.

Without increased offtake and financing support, we expect that the landscape for capital-intensive, high-durability CDR may consolidate

CDR Buyers Will Determine Which Projects Get Built

The supply-side ecosystem features a sufficient number of high-quality CDR suppliers with the potential to scale. These suppliers face purchasing behavior insufficient to meet buyers' own stated climate goals. In this environment, every CDR procurement decision matters. Companies that delay procurement risk missing their own climate targets while also ceding competitive advantage to early movers who secure the limited supply of high-quality credits. 

Five Actions to Strengthen the CDR Market

Buyers and investors can play a critical role in reducing project risk and strengthening the CDR market. Our full report details five essential actions:

1. Use purchasing power wisely
2. Prioritize project diligence
3. Construct bankable contracts
4. Support market data transparency and CDR goals
5. Undertake project assurance

Each action addresses specific market failures and, when implemented strategically, can significantly improve the likelihood that high-quality CDR projects reach operation and deliver credits as contracted.

With 2030 only four years away, the window for action is rapidly closing. Early movers will secure supply and define market standards, while those who wait risk entering a crowded market with limited access to high-quality credits and escalating prices.

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Frequently Asked Questions

Why did the voluntary carbon market stall in 2025 despite rising corporate climate commitments?

Retirements fell 7% even as SBTi reported a 227% surge in companies setting near-term and net-zero targets. The gap reflects that most companies with 2030 goals haven't yet moved from setting targets to actually procuring credits.

Is carbon dioxide removal a proven market today, or still emerging?

CDR remains a small segment—about 5% of 2025 retirements—but it has an unusually active forward market, with buyers committing today to volumes delivered years from now. High-durability pathways like biochar and geologic storage are still early-stage relative to nature-based credits.

How does the new SBTi Net-Zero Standard affect corporate carbon credit strategy?

Under the new SBTi Net-Zero Standard, credits still can't be counted toward scope 1, 2, or 3 targets. But it introduces a voluntary recognition program starting in 2027, and requires large companies to begin purchasing carbon removals from 2035, starting at 1% of their footprint.

What should CDR buyers prioritize given current market conditions?

Given how concentrated forward offtake activity is today, buyers should prioritize rigorous project diligence and bankable contract structures over simply committing volume—the 2026 State of the Voluntary Carbon Market report details five recommended actions in more depth.

Key Takeaways

• Buyers have been navigating the low-carbon fuels (LCF) market without a map.  The LCF market is expanding rapidly, but standards, definitions, and quality claims vary widely across regions, certification schemes, and regulatory systems, leaving voluntary buyers without a holistic framework for evaluating what they procure.
• Certifications cover some of the picture, not all of it. Existing certification schemes provide valuable assurance but vary in scope and rigor, and few, if any, were designed specifically with voluntary market buyers in mind. 
• The 2026 criteria give buyers a legible quality framework. The 2026 Criteria for High-Quality Low Carbon Fuels bring together key sustainability considerations across six principles, including social and environmental integrity, carbon accounting, additionality, feedstock sourcing, and leakage, giving buyers and producers a legible, living framework to navigate procurement decisions with confidence.

Verifying Quality Is Challenging in the Current Low-Carbon Fuels Market

For airlines, logistics companies, and large corporations with hard-to-abate transportation emissions, low-carbon fuels (LCFs) have become an important part of the decarbonization toolkit. Yet it remains difficult for procurement teams to answer a fundamental question: what does high-quality procurement actually look like? 

Standards, definitions, and sustainability claims vary widely across regions, certification bodies, and regulatory programs. The result is a market where quality is difficult to verify, certifications are difficult to compare, and the gap between a fuel's claims and its actual sustainability profile can be hard to close. Sustainable production will be especially critical as the market scales, because low-carbon fuel systems are deeply embedded in land, agriculture, forestry, and communities. 

The 2026 Criteria for High-Quality Low Carbon Fuels are designed to close this gap, giving voluntary buyers a consistent framework to evaluate the quality of what they procure and identify where additional diligence is still needed.

What Is a Low-Carbon Fuel?

For the purposes of the criteria, a low-carbon fuel, or LCF, is defined as a fuel or energy source whose lifecycle greenhouse gas (GHG) emissions are lower than those of a relevant, use-case-specific fossil fuel alternative. In this case, we are referring to the physical biofuel and its associated environmental attributes. 

While LCFs may be produced through biological, synthetic, or other non-fossil pathways, the 2026 edition focuses on biofuels for transportation, which currently represent the majority of LCF production and use. 

Understanding the Complex LCF Regulatory and Certification Landscape

The LCF market sits at the intersection of multiple regulatory and voluntary markets. In the US, this includes compliance programs such as the Renewable Fuel Standard (RFS) and state-level Low Carbon Fuel Standards (LCFS). Europe, the United Kingdom, Canada, and many other nations host comparable programs, often with specialized regulatory regimes for various transport sectors, e.g., aviation or maritime. 

These regulatory markets coincide with and often intersect voluntary markets, which contain a multitude of standards and certifications. For producers, this creates a complex landscape of market options. For buyers, it creates a signal problem: a fuel may carry one or more certifications, comply with one or more regulatory programs, and still leave meaningful sustainability questions unaddressed.

Several organizations, including the Roundtable on Sustainable Biomaterials (RSB) and the International Sustainability and Carbon Certification (ISCC), have developed widely used standards for LCFs. These certifications assess supply chains from feedstock to end use and provide important baseline assurance. 

However, they were developed with different primary audiences in mind and can vary in scope and rigor. Few existing schemes were designed to serve as a comprehensive sustainability reference for voluntary market buyers evaluating what a given fuel's certification covers and where gaps may still exist.

Simplifying High-Quality Procurement for Voluntary Buyers 

The 2026 Criteria for High-Quality Low Carbon Fuels are not designed to replace or compete with existing certification schemes. Rather, they consolidate key sustainability considerations from across the landscape of existing frameworks into a single, legible reference built specifically for voluntary market decision-makers.

The criteria apply across the full LCF supply chain, covering not only fuel producers but also fuel blenders, aggregators, and certificate traders. This LCF systems view encompasses the full set of production, certification, and procurement arrangements through which LCFs are generated and claimed. This reflects the reality that sustainability outcomes in this market are shaped by many actors, not just at the point of production.

The criteria distinguish between requirements that must be met (minimum thresholds for quality and integrity) and considerations that should be addressed, reflecting best practices and aspirational standards. This distinction is intentional: the criteria set a floor while leaving room for market participants to demonstrate quality in ways appropriate to their specific context. 

The criteria are organized around six core principles that together define what high-quality LCF production and procurement looks like. 

Six Principles for Procuring High-Quality Low-Carbon Fuels

1. Social harms, benefits, and environmental justice: preventing new harms to communities, reducing existing ones, and ensuring equitable distribution of benefits
2. Environmental harms and benefits: minimizing impacts on air, soil, water, and biodiversity
3. Carbon accounting: accurately quantifying lifecycle GHG emissions using credible methodologies and tracking environmental attributes to prevent double-counting
4. Additionality: demonstrating that voluntary market support enables outcomes that would not otherwise occur
5. Feedstock sourcing: ensuring responsible and equitable sourcing practices and requiring end-to-end chain-of-custody documentation traceable to the point of generation
6. Leakage: assessing and mitigating activity-shifting and market leakage associated with the LCF system

Where a fuel's existing certification or regulatory program adherence already addresses one or more of these core principles, that coverage should be disclosed to the buyer by the producer. Buyers can then use the criteria to identify where certification coverage aligns with quality expectations, and where supplemental diligence is needed.

A Living Framework for a Market in Motion  

The LCF market will continue to evolve as policy frameworks are shifting, certification systems are maturing, and new production pathways are emerging. The 2026 edition reflects the current state of the LCF market and is intended as a living resource, with future updates possible as the market develops and new science emerges. Future editions may expand to cover synthetic LCF pathways, renewable natural gas, and sector-specific considerations such as maritime fuels.

For buyers navigating voluntary LCF procurement, the criteria offer a practical starting point: a framework to evaluate what existing certifications cover, identify where additional diligence is needed, and build procurement decisions on a consistent quality foundation. For producers, they provide clear guidance on what a sustainability demonstration looks like for voluntary market buyers.

Read the 2026 Criteria for High-Quality Low Carbon Fuels to learn more about how the criteria apply to your procurement strategy or production system.

Frequently Asked Questions

What is a low-carbon fuel?
A low-carbon fuel is a fuel whose lifecycle greenhouse gas emissions are lower than a comparable fossil fuel alternative for the same use case. The 2026 LCF Criteria focus specifically on biofuels for transportation, which currently make up most LCF production and use.

What do the 2026 Criteria for High-Quality Low Carbon Fuels cover?
The criteria are organized around six principles: social harms, benefits, and environmental justice; environmental harms and benefits; carbon accounting; additionality; feedstock sourcing; and leakage. Together they give buyers and producers a consistent way to evaluate what high-quality LCF production and procurement looks like.

Do the LCF criteria replace existing certifications like RSB or ISCC?
No. The criteria aren't designed to replace or compete with existing certification schemes such as the Roundtable on Sustainable Biomaterials (RSB) or the International Sustainability and Carbon Certification (ISCC). Instead, they consolidate key sustainability considerations from across those frameworks into a single reference so buyers can see what their certification already covers and where supplemental diligence may be needed.

Who do the LCF criteria apply to across the supply chain?
The criteria apply across the full LCF supply chain, not just producers, but also feedstock suppliers, fuel blenders, aggregators, and certificate traders, reflecting that sustainability outcomes are shaped by many actors, not only the producer.

What's the difference between the "must" and "should" requirements in the LCF criteria?
"Must" requirements set minimum thresholds for quality and integrity that need to be met, while "should" considerations reflect best practices and aspirational standards market participants can work toward. This sets a floor while leaving room for participants to demonstrate quality in ways suited to their specific context.

Key Takeaways

• Concrete and steel contribute 13% of global CO2 emissions. These materials represent substantial scope 3 emissions for companies that are building new infrastructure, including data centers.
• Low-emission alternatives and production technologies are nascent and not yet widely deployed.
• Environmental attribute certificates (EACs) are an innovative solution that can stimulate manufacturing of sustainable commodity materials and overcome market barriers to direct physical procurement.
• Relae (formerly Carbon Direct) and Microsoft developed criteria to guide Microsoft’s high-quality EAC procurement, accelerate decarbonization, and catalyze market expansion for decarbonized materials across supply chains. 
• These criteria cover seven key areas: qualifying conditions, social harms and benefits, environmental harms and benefits, additionality and baselines, catalytic impact, verifiability, and leakage.

A Vision for Low-Carbon Concrete and Steel

Concrete and steel are essential for modern construction, but are carbon-intensive. Combined, they account for approximately 13% of global carbon dioxide (CO2) emissions. ​As the demand for data centers and infrastructure development continues to grow, so do the embodied emissions from concrete and steel. There is an urgent need to decarbonize these sectors so that construction of new facilities remains consistent with climate commitments.​

However, the markets for low-carbon concrete and steel are still in their infancy. Market barriers such as low production volumes, contracting complexity, geographic concentration of supplies, and long-distance transportation limit buyers’ ability to directly procure low-carbon building materials. As buyers and sellers overcome these barriers, the market for low-carbon building materials will mature, giving producers the confidence to invest in new manufacturing facilities and giving buyers access to decarbonized materials directly in their supply chain.

Environmental attribute certificates (EACs) represent the sustainability attributes of a material commodity, unbundled and transacted separately from the physical commodity. EACs are transacted at a price that reflects the additional cost of sustainably producing the material. While barriers to direct procurement of low-carbon materials persist, EACs can serve as a powerful tool to signal demand for low-carbon concrete and steel, catalyze market expansion, and accelerate decarbonization.

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Microsoft’s Approach to Emissions from Building Materials ​

To address embodied emissions and help achieve its ambitious 2030 carbon-negative goal, Microsoft aims to deeply reduce its scope 3 emissions, including from building materials, by more than half compared to a 2020 baseline. In 2023, scope 3 emissions made up over 96% of Microsoft’s total greenhouse gas footprint. To meet its 2030 target, Microsoft is focusing on addressing supply-chain emissions related to data center construction and the embodied carbon of the commodity materials used to build them. Microsoft is already working to decarbonize its building material supply chain using the following three tactics:

• Reduce the need for concrete and steel through innovative building design or the use of lower-carbon alternatives, such as sustainably sourced mass timber.
• Directly engage with suppliers to procure low-carbon alternatives to conventional concrete and steel.‍
• Invest in and help pilot new low-carbon production pathways.

EACs represent a fourth approach to decarbonization that can both reduce emissions and catalyze industry growth. Taken together with Microsoft’s design, procurement, and investment tactics, these actions underpin a comprehensive strategy for long-term decarbonization of the built environment.

High-Quality EACs Support Decarbonization

EACs offer a virtual, market-driven solution to decarbonize the built environment by allowing companies to support low-carbon material production when physical supply chain barriers impede direct procurement. ​EACs for concrete and steel function similarly to other market-based decarbonization mechanisms such as sustainable aviation fuel (SAF) certificates in the aviation sector and renewable energy certificates (RECs) in the energy sector.

These mechanisms work by decoupling the environmental benefits of low-carbon production from the physical materials themselves. EACs allow companies to claim the environmental benefits of physical low-carbon concrete or steel production, even if they do not directly or physically source those materials. EACs provide a verified claim that a purchaser has procured a product with lower emissions, enabling companies to meet climate targets and demonstrate their commitment to sustainability.

Due to their virtual nature, which limits physical oversight of the supply chain, EACs also exacerbate risks such as double counting, greenwashing, fraud, social harms, and environmental harms. Therefore, adhering to transparent, rigorous criteria is foundational to mitigating these risks.

New Criteria to Guide Procurement of High-Quality EACs

To support the integrity and effectiveness of EACs in these sectors, Relae and Microsoft have co-developed Criteria for High-Quality Environmental Attribute Certificates in the Concrete and Steel Sectors. These robust criteria serve as a public resource for companies seeking credible and impactful EAC procurement pathways for low-carbon concrete and steel.

The criteria address seven key areas:

1. Qualifying conditions: EACs must complement, not displace, direct procurement and represent significant emissions reductions. ​
2. Social harms and benefits: EACs must not further social harms and should promote community engagement and social benefits such as meaningful workforce development opportunities and community climate resilience.
3. Environmental harms and benefits: EACs must not perpetuate environmental harm, but instead should mitigate risks and, ideally, provide additional environmental benefits.
4. Additionality and baselines: Projects funded by EACs must drive real, meaningful emissions reductions ​in terms of financial, regulatory, and common practice additionality.
5. Catalytic impact: Prioritize transformative technologies with sector-wide decarbonization potential. ​
6. Verifiability: Set a high bar for documentation, transparency, and independent auditing. ​
7. Leakage: Address risks of emissions displacement to support net-positive outcomes. ​

These criteria provide a robust framework for companies and stakeholders to evaluate and implement commodity EACs effectively, supporting impactful change. ​They balance rigor with flexibility and acknowledge the nascent state of the markets for low-carbon concrete and steel. Sectoral decarbonization will advance over time, shifting the thresholds for what is considered significant, additional, and catalytic in EAC transactions. This science-driven framework can adapt to advancements in policy, industry practices, and technological readiness, ensuring EACs remain a relevant and impactful tool for years to come. ​

Sector-Specific Insights

In addition to providing overarching criteria and guidance on procuring EACs for the built environment, Criteria for High-Quality Environmental Attribute Certificates in the Concrete and Steel Sectors also provides insights into the unique challenges and opportunities of decarbonizing concrete and steel.

Decarbonizing Concrete

EACs can support innovative decarbonization strategies for concrete, such as producing alternatives to clinker and cement, adopting supplementary cementitious materials (SCMs), and reducing emissions from cement kilns through electrification or integrating carbon capture and storage (CCS). ​Performance-based standards and evolving building codes may also unlock new opportunities for low-carbon concrete. ​

The Global Cement and Concrete Association (GCCA) publishes a rating system, Low Carbon Concrete (or Cement) Ratings, which defines eight separate low-carbon grades (AA through G). These grades correspond to the depth of decarbonization and are based on a sliding scale related to the material’s compressive strength. When developing these criteria, Microsoft considered grades AA through D to be eligible for consideration in its EAC procurements.

Decarbonizing Steel

EACs can support transformative technologies for decarbonizing steel, like direct reduced iron (DRI) with electric arc furnaces (EAF) powered by green or blue hydrogen. This support can enable the steel sector to move beyond incremental improvements and focus on capital-intensive solutions that have the potential to reshape the industry. ​

ResponsibleSteel, an independent standards and certification organization with membership that is broadly representative of the steel industry, publishes decarbonization progress levels, with four separate grades (PL1–PL4). These grades correspond to the depth of decarbonization and are based on a sliding scale related to the fraction of recycled scrap use in the steel manufacturing process. When developing these criteria, Microsoft included levels PL2 through PL4 for consideration in its EAC procurements.

A Blueprint for EAC Market Development ​

Relae and Microsoft crafted Criteria for High-Quality Environmental Attribute Certificates in the Concrete and Steel Sectors as a public resource that can help shape the future of the commodity EAC market. ​

These criteria are designed to:

• Communicate intent: Communicate Microsoft's intent to support the decarbonization and scaling of physical commodity supply chains where they have been previously limited.‍
• Guide decision-making: Serve as a public guide for Microsoft's decision-making process, explaining the rationale behind pursuing or declining specific EAC pathways.‍
• Set high-integrity standards: Maintain high integrity for EACs at an early stage, ensuring they are used to enable future physical procurement by supporting market development.‍
• Stimulate partnership opportunities: Encourage potential partnerships and purchasing pipelines by clearly describing criteria for high-quality EACs.‍
• Publicly share detailed thinking: Build on previous work and publicly share detailed thinking, aiming to stimulate market development and guide procurement decisions.

Practical Recommendations for Implementing EACs

Whether you are a supplier, buyer, policymaker, or sustainability advocate, these new criteria offer actionable insights to help you navigate the complexities of EACs in the built environment. ​From setting significance thresholds to ensuring verifiability to avoiding double counting, the criteria provide clear guidance to maximize the impact of EAC-supported projects.

Beyond the technical aspects of EACs, these criteria aim to address their broader social and environmental implications. The criteria focus on the importance of community engagement, transparency, and equitable distribution of benefits in EAC project planning, ensuring that decarbonization efforts contribute to a more sustainable and just economy. ​The criteria are backed by extensive research, stakeholder consultations, and industry expertise.

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Meera Atreya, John Dees, David Madrid Garcia, Katherine Gomes, Grant Gutierrez, and A.J. Simon authored the Criteria for High-Quality Environmental Attribute Certificates in the Concrete and Steel Sectors. We appreciate Julio Friedmann and Colin McCormick for their valuable technical insights. Adrianna Sutton, Molly Tucker, and Britt Warthen provided essential editorial and production support.

We are especially grateful to Julia Fidler and Brian Sifton, previously at Microsoft, for commissioning this report, providing detailed input, and engaging deeply with the Relae Science Team every step along the way. Special thanks to Katie Ross at Microsoft, whose leadership and coordination made the report possible.

We also extend our appreciation to the teams at RMI and Environmental Resources Management for their time, thoughtful feedback, and prior publications, which helped inform and complement this work.

Frequently Asked Questions

What is an environmental attribute certificate (EAC), and how does it differ from buying low-carbon concrete or steel directly? 

An environmental attribute certificate represents the sustainability attributes of a commodity material such as concrete or steel, unbundled from the physical material and transacted separately from it. Direct procurement means a buyer purchases low-carbon concrete or steel and takes physical delivery of it for a specific project. An EAC purchase instead allows a buyer to fund and claim the environmental benefit of sustainably produced materials that are sold as typical commodities, and apply that benefit against conventional commodities in their own supply chain. EACs are priced to reflect the additional cost of producing the material sustainably, which sends a demand signal to producers. This makes EACs useful where market barriers—limited production volumes, geographic concentration of supply, or long-distance transportation—prevent buyers from sourcing low-carbon materials directly.

How do EACs for concrete and steel compare to renewable energy certificates (RECs) or sustainable aviation fuel (SAF) certificates?

Environmental attribute certificates for concrete and steel share a structure with renewable energy certificates and sustainable aviation fuel certificates: each decouples the environmental benefit of low-carbon production from the physical product, letting a buyer fund and claim that benefit without taking physical delivery. There are two key differences. First, conventional RECs represent electricity with a zero-emissions footprint, while every tonne of concrete or steel behind an EAC still carries embodied emissions — the certificate demonstrates reduction against a baseline, not a zero-emission product. Second, REC and SAF markets are established, while EACs for concrete and steel are nascent. Both differences are why rigorous criteria matter: quantifying the reduction credibly is harder, and the virtual structure carries risks of double counting, greenwashing, and fraud.

Will EACs let companies claim emissions reductions without actually reducing their built environment climate footprint?

An EAC purchase does not change the materials in a buyer's own buildings; it funds lower-emission production elsewhere in the market. Credible EAC frameworks therefore require that certificates complement rather than displace direct procurement, that they represent significant reductions against a defensible baseline, and that the funded project would not have proceeded without EAC revenue. The criteria published by Relae and Microsoft enable buyers to address these requirements directly in their procurement processes - addressing the climate and reputational risks of low-quality certificates. Used this way, EACs become an additional tool to address emissions from the built environment, supplementing design changes, direct procurement, and investment in new production pathways.

Who should use these criteria?

Criteria for High-Quality Environmental Attribute Certificates in the Concrete and Steel Sectors, co-developed by Relae and Microsoft, is a public resource intended for four audiences. Buyers pursuing scope 3 reductions can use it to evaluate whether a given certificate represents a credible, additional emissions reduction. Suppliers and project developers can use it to understand what purchasers of high-quality certificates look for before bringing a project to market. Policymakers and standards bodies can draw on it while shaping rules for an emerging market. Sustainability practitioners and advocates can use it as a reference point for assessing claims made about low-carbon concrete and steel. The criteria are designed to evolve as these sectors decarbonize, and users may adapt them to meet their own levels of capability and ambition. 

Key Takeaways

• High-quality carbon dioxide removal (CDR) projects require robust project management and oversight to deliver credits on time and at the promised volume; delivery risk is a distinct concern that quality standards alone don't catch.
• The sixth edition of the Criteria for High-Quality Carbon Dioxide Removal is the first to provide an approach to evaluating both credit quality and delivery risk, adding a new delivery risk appendix built around the TECOP framework: technical, economic, commercial, organizational, and political risk.
• The 2026 Criteria provides a framework for developers, investors, and buyers to evaluate both project quality and delivery risk.
• This year's update draws on 170 new diligence reports from 2025 and the input of more than 60 subject matter experts, building on a foundation of six years of lessons from professional diligence across hundreds of real-world CDR projects.

The Criteria Create a Shared Standard for Credit Quality

Relae (formerly Carbon Direct) first launched the Criteria for High-Quality Carbon Dioxide Removal (the Criteria) in collaboration with Microsoft in 2021 to help rapidly and justly scale the development of high-quality carbon dioxide removal (CDR) credits. The market didn't yet have a shared definition of what "high-quality" meant, so we laid out transparent, science-based benchmarks that gave developers, investors, and buyers a common foundation to work from. Every year since, we have gone back and sharpened those benchmarks so that they keep pace with the quickly evolving industry.

But a shared definition of quality doesn't guarantee the delivery of credits as planned. The 2026 edition is the first to tackle that gap directly, pairing the Criteria's quality benchmarks with a new framework for evaluating delivery risk.

The Six Principles of High-Quality Carbon Removal

The Criteria defines six science-based principles that apply across engineered, hybrid, and nature-based CDR approaches:

• Social harms, benefits, and environmental justice: The extent to which the project prevents new social harms to people and communities, reduces existing harms, and provides meaningful benefits distribution.
• Environmental harms and benefits: The extent to which the project minimizes and mitigates environmental harms, as well as provides environmental benefits.
• Additionality and baselines: The evidence that the project’s carbon removal would not have occurred without carbon finance.
• Measurement, monitoring, reporting, and verification (MMRV): The ability to accurately quantify carbon removal in a repeatable and verifiable way, and to develop a plan for long-term monitoring of the project.
• Durability: The likelihood that removed carbon remains stored over time, with mechanisms in place to mitigate reversal risk.
• Leakage: The extent to which project activities cause increased emissions elsewhere.

These principles provide a consistent foundation for carbon removal procurement, evaluation, and project benchmarking.

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Supporting the Delivery of High-Quality CDR Credits

"Projects must work better operationally and be more commercial. Quality and delivery risk shape a project's risk profile at every point in its life, and this edition of the Criteria is the first to give buyers a way to judge both at once." Dr. Julio Friedmann, Chief Scientist, Relae

Designing projects to meet high-quality CDR criteria is only part of the challenge. Effective project planning, management, and execution are also essential to ensure that high-quality CDR tonnes successfully reach the market as planned. As discussed in CDR 2.0: Five Pillars of Successful Project Deployment and Delivery, managing delivery risk requires developers, investors, and buyers to understand the risks that can affect project success and align on how these risks are assessed and mitigated.

To support this alignment, the 2026 Criteria introduced a new Delivery Risk Appendix, which establishes a common framework and language for identifying and evaluating key delivery risks for the first time. Drawing on our broader observations of the carbon removal market and established approaches to project risk management, the appendix highlights common delivery risks across two broad CDR project types: open systems and closed systems. It organizes these risks into five categories: technical, economic, commercial, organizational, and political factors, also known as the TECOP framework. 

The TECOP Framework for CDR Delivery Risk

• Technical delivery risks are associated with the technical feasibility of the project design, implementation, and long-term operation of the project
• Economic delivery risks are associated with the project’s financing structure, financial modeling assumptions, and expenditure profile
• Commercial delivery risk reflects the extent to which a project's purchase agreements, supply arrangements, and key contractual relationships are secured or well-advanced. 
• Organizational delivery risks center on the project developer's capacity and capability to successfully plan, execute, and manage a project of the appropriate size and complexity.  
• Political delivery risks are associated with governance, policies, and potential changes in regulatory environments, as well as the local communities’ perception of and willingness to participate in projects.

New Additions to the 2026 Criteria

Since publishing the 2025 Criteria, Relae has conducted an additional 170 diligence reports across established and emerging CDR pathways, ranging from reforestation and enhanced rock weathering (ERW) to direct air capture (DAC). To date, less than 10% of all 900+ projects the team has reviewed have met the bar for high-quality. These diligence efforts, together with insights from market analysis and ongoing synthesis of the latest scientific and technical literature, have deepened our understanding of how CDR project quality has evolved over the past year. 

The 2026 Criteria leverage these insights and the expertise of more than 60 subject matter experts to reflect advances across the CDR industry and address key weaknesses that remain in the market across all pathways. 

A few of the most significant updates to the Criteria include:

Addition of Direct Counterparty Considerations: Direct counterparties are the organizations that developers partner with, and are structurally dependent on, to generate credits. This can include: 

• Primary feedstock providers (e.g., mines, biomass providers, tree nurseries)
• Major implementing partners (e.g., local implementation partners, base facilities, transportation and storage providers, major product offtakers)
• Land owners that make up a significant proportion of project land 

To reflect the key role that direct counterparties play in high-quality credit generation, developers must conduct diligence and disclose on their direct counterparties to demonstrate that they are not causing social or environmental harm.

Increased Rigor for Enhanced Rock Weathering Projects: Over the past year, ERW’s presence in the CDR market has grown substantially, and so too has the market’s understanding of the corresponding scientific and technical rigor required to deliver high-quality tonnes. The 2026 Criteria raised the bar for how ERW projects:

• Measure and prove their carbon removal claims
• Mitigate risks related to potentially toxic elements (PTEs)
• Incorporate more sophisticated farmer protections and benefits 

Projects now have to back up their numbers with multiple physical field measurements, not just computer models; and they must now track and account for every significant loss pathway, from plants taking up minerals to carbon escaping from rivers and oceans.

Use of Dynamic Baselines for ARR Projects: ARR projects are increasingly using dynamic baselines to provide a more accurate reflection of the counterfactual scenario (e.g., what would have happened in the absence of the project). This is reflected in the 2026 Criteria with a requirement that ARR projects, with the exception of agroforestry projects, use dynamic baselines with statistically matched controls.

What’s Next?

The 2026 Criteria create a clear, science-driven framework for both designing and delivering measurable, just, and durable carbon removal. However, the Criteria cannot ensure high-quality tonnes reach the market on its own; good criteria do not replace robust diligence. To put these criteria into practice, we encourage developers, standard-setting bodies, buyers, investors, and policymakers to consider how the Criteria can be used to inform their role in enabling the carbon market to deliver high-quality tonnes and to engage in deep diligence and ongoing monitoring over the life of a project.

This edition of the Criteria reflects what we have learned over the past year, but our work is not done. We will continue to update it so that it remains a living document that evolves with the science and the market. To do so effectively, it must be a collaborative effort; we welcome input from carbon market actors, academia, and communities.

Frequently Asked Questions

Who publishes the Criteria for High-Quality Carbon Dioxide Removal, and how often is it updated?

Relae (formerly Carbon Direct) first published the Criteria for High-Quality Carbon Dioxide Removal with Microsoft in 2021 and have updated it every year since. The 2026 edition reflects six years of lessons from real-world project diligence and advances in climate science.

What are the six principles of the Criteria for High-Quality Carbon Dioxide Removal?

The Criteria define six science-based principles that apply across all CDR pathways: social harms, benefits, and environmental justice; environmental harms and benefits; additionality and baselines; measurement, monitoring, reporting, and verification (MMRV); durability; and leakage.

What CDR pathways does the Criteria cover?

The Criteria include pathway-specific criteria across nine CDR pathways: afforestation, reforestation, and revegetation (ARR); mangrove forestation; improved forest management (IFM); soil carbon; enhanced rock weathering (ERW) in croplands; biomass carbon removal and storage (BiCRS); abiotic marine CDR; carbon mineralization; and direct air capture (DAC).

What is delivery risk in carbon removal?

Delivery risk is the likelihood that a project generates credits on the timeline and at the quantity committed to buyers. It's a distinct concern from credit quality: even a high-quality project can fail to deliver as planned because of technical, economic, commercial, organizational, or political risk, the five categories the Criteria's TECOP framework evaluates. The 2026 Criteria's new Delivery Risk Appendix gives developers, investors, and buyers a shared benchmark for identifying and managing these risks before they derail a project.

What's the relationship between carbon removal credit quality and delivery risk?

Credit quality and delivery risk are distinct but interrelated. A project that fails to deliver credits as planned reduces the availability of high-quality CDR tonnes in the market, and weaknesses in credit quality can themselves increase delivery risk by creating buyer uncertainty or limiting access to project financing. The 2026 Criteria provides a framework for evaluating both quality and delivery risk.