Case study: Carbon markets & offsets integrity — a startup-to-enterprise scale story

In 2019, Sylvera launched from a London co-working space with three employees and a single hypothesis: satellite imagery and machine learning could independently verify whether forest carbon offset projects were actually sequestering the carbon they claimed. By early 2026, the company had raised over $100 million in venture capital, built a ratings platform covering more than 900 carbon projects worldwide, and secured enterprise contracts with buyers including JPMorgan, Shell, and the Swiss government. Sylvera's trajectory from a seed-stage startup to a market-defining enterprise illustrates how the voluntary carbon market's credibility crisis created a massive opening for technology-driven integrity solutions, while also exposing the operational, regulatory, and commercial challenges of scaling in a market that was itself undergoing fundamental transformation.

Why It Matters

The voluntary carbon market (VCM) reached $2.1 billion in transaction value in 2023, according to Ecosystem Marketplace, but volumes contracted by 8% year-over-year as corporate buyers hesitated amid a wave of investigative reporting and academic research questioning the additionality and permanence of popular offset project types (Ecosystem Marketplace, 2024). A January 2023 investigation by The Guardian, Die Zeit, and SourceMaterial found that more than 90% of Verra's rainforest offset credits were likely phantom credits that did not represent genuine carbon reductions. The resulting credibility shock wiped out buyer confidence and created urgent demand for independent verification tools.

For corporate sustainability teams, the stakes are existential. Companies that purchased low-integrity offsets face reputational risk, regulatory exposure under tightening anti-greenwashing rules (the EU Green Claims Directive mandates substantiation of environmental claims by 2026), and potential write-downs on carbon credit portfolios. The Integrity Council for the Voluntary Carbon Market (ICVCM) released its Core Carbon Principles (CCPs) assessment framework in 2024, establishing for the first time a standardized quality benchmark. Companies operating in this market need the tools, data, and methodologies to distinguish high-integrity credits from junk credits before they purchase.

Key Concepts

Additionality refers to whether a carbon offset project reduces emissions beyond what would have happened in a business-as-usual scenario. A forest protection project is additional only if the forest would have been deforested without the project's intervention.

Permanence measures whether sequestered carbon stays out of the atmosphere for the claimed duration, typically 30 to 100 years. Forest projects face permanence risks from wildfire, illegal logging, and policy changes.

MRV (Measurement, Reporting, and Verification) encompasses the full process chain of quantifying emissions reductions, documenting them according to registry standards, and independently confirming the reported values.

Baseline crediting assigns credits based on the difference between a modeled counterfactual scenario (the baseline) and observed outcomes. Inflated baselines produce phantom credits that represent no real climate benefit.

Core Carbon Principles (CCPs) are the ICVCM's quality threshold criteria, covering additionality, permanence, robust quantification, and sustainable development safeguards. Only credits meeting CCP criteria receive the CCP label.

KPI	Definition	Good Benchmark	Poor Benchmark
Additionality Score	Independent assessment of whether emissions reductions are additional	>80% probability	<40% probability
Over-crediting Ratio	Credits issued vs. verified actual reductions	<1.1x	>2.0x
Permanence Risk Rating	Probability of reversal within crediting period	<10%	>30%
Registry Transparency Index	Completeness of publicly available project documentation	>90% fields populated	<50% fields populated
Buyer Repeat Purchase Rate	Percentage of corporate buyers repurchasing from the same project	>60%	<25%
Time to Verification	Days from monitoring to issuance of verified credit	<90 days	>365 days

What's Working

Sylvera's core innovation was applying remote sensing data, specifically LiDAR-derived canopy height models, Sentinel-2 multispectral imagery, and synthetic aperture radar (SAR), to independently estimate above-ground biomass in forest carbon projects. This approach bypassed the traditional reliance on project developer self-reporting, which the Guardian investigation had exposed as systematically biased. By 2024, Sylvera's platform could assess a REDD+ project's actual carbon stock within plus or minus 15% accuracy, compared to the plus or minus 50% uncertainty ranges common in traditional ground-based sampling approaches.

The company's first enterprise client, signed in late 2021, was a major European energy company seeking to validate a $40 million portfolio of forest carbon credits. The engagement revealed that approximately 35% of the portfolio's credits were rated "D" (lowest quality) on Sylvera's four-tier rating system, primarily due to inflated baselines and questionable additionality. This finding alone justified the platform's annual subscription cost many times over and became a powerful sales proof point for subsequent enterprise deals.

BeZero Carbon, a London-based competitor that launched in 2020, took a complementary approach by building a credit-level rating system analogous to bond credit ratings, assigning letter grades from AAA to D based on eight risk factors. BeZero's model proved especially attractive to financial institutions: by 2025, more than 30 asset managers and banks used BeZero ratings as a screening tool for carbon credit trading desks. Calyx Global, founded in Portland, Oregon, added a third model focused on compliance-grade methodological assessments, providing credit-level opinions that aligned with ICVCM CCP criteria.

The market infrastructure layer also matured. Xpansiv's CBL platform, the dominant exchange for voluntary carbon credit trading, integrated third-party ratings data from Sylvera and BeZero directly into its trading interface in 2024, enabling buyers to filter credits by quality score alongside price. This integration moved ratings from a due diligence tool to a price discovery mechanism, with AAA-rated credits trading at 3x to 5x premiums over unrated credits of the same project type.

What's Not Working

Scaling a carbon integrity business exposed several structural challenges that technology alone could not solve.

Methodology fragmentation remained a persistent barrier. Verra, Gold Standard, the American Carbon Registry, and the Climate Action Reserve each used different baseline methodologies, monitoring protocols, and additionality tests. Sylvera and BeZero had to build separate assessment models for each registry and project type (REDD+, cookstoves, renewable energy, direct air capture), with each model requiring months of calibration and validation. By 2025, Sylvera covered seven project types comprehensively but acknowledged that another eight to ten categories, representing roughly 25% of market volume, still lacked sufficient ratings coverage.

Data access limitations created blind spots. While satellite imagery provided excellent coverage for forest projects, it was far less useful for assessing cookstove distribution programs in Sub-Saharan Africa, methane capture at landfills, or industrial gas destruction projects. These project types required ground-truth data that was expensive to collect and often controlled by project developers who had little incentive to share unfavorable information. Calyx Global estimated that data access constraints reduced the effective ratable universe to approximately 60% of issued credits.

Revenue model tension proved challenging. Enterprise buyers wanted bespoke portfolio assessments and advisory services, which generated high per-contract revenue but were labor-intensive and difficult to scale. Platform subscription models offered better unit economics but required a critical mass of rated projects and continuous data updates to justify annual fees of $50,000 to $250,000. Sylvera's pivot toward a hybrid model in 2023, combining platform subscriptions with API access for trading desks, improved margins but increased engineering complexity.

Market contraction timing complicated fundraising. Sylvera's Series B in September 2022 ($32 million led by Balderton Capital) closed just as the VCM downturn was beginning. The company had to extend its runway through 2024 by reducing headcount by 15% and deferring expansion into Asia-Pacific markets. BeZero similarly adjusted its growth plans, laying off approximately 20% of staff in early 2024 despite strong product-market fit, because its customer base of carbon trading desks was itself shrinking.

Regulatory uncertainty around whether integrity ratings would become mandatory or quasi-mandatory created strategic ambiguity. The ICVCM's CCP framework endorsed the concept of independent assessment but stopped short of designating specific rating providers as approved assessors. Companies like Sylvera invested heavily in ICVCM alignment without certainty that the investment would translate to a regulatory moat.

Key Players

Established Organizations

Verra: the largest voluntary carbon credit registry, administering the Verified Carbon Standard (VCS) program with over 1,900 registered projects and more than 1 billion credits issued since inception.

Gold Standard: a carbon credit registry founded by WWF that focuses on projects delivering verified sustainable development co-benefits alongside emissions reductions.

Integrity Council for the Voluntary Carbon Market (ICVCM): the independent governance body that developed the Core Carbon Principles framework to establish a global quality benchmark for voluntary carbon credits.

Xpansiv (CBL): the leading spot exchange for environmental commodities, processing over $6 billion in carbon credit transactions in 2024 and integrating third-party quality ratings into its trading platform.

Startups

Sylvera: a London-based carbon intelligence platform using satellite data and machine learning to rate carbon credit quality, with over $100 million in total funding and enterprise clients across energy, finance, and technology sectors.

BeZero Carbon: a London-based carbon credit ratings agency providing AAA-to-D letter grades across eight risk dimensions, used by more than 30 financial institutions for trading desk screening and portfolio assessment.

Calyx Global: a Portland-based independent carbon credit rating firm providing compliance-grade methodological assessments aligned with ICVCM Core Carbon Principles criteria.

Pachama: a San Francisco-based technology company using remote sensing and AI to evaluate forest carbon projects, working with buyers including Microsoft, Shopify, and SoftBank.

Investors and Funders

Balderton Capital: lead investor in Sylvera's $32 million Series B, with a thesis on data infrastructure for emerging environmental markets.

Index Ventures: co-led Sylvera's Series A alongside the sustainability-focused fund of a major European family office.

Lowercarbon Capital: early investor in Pachama, backing remote-sensing-first approaches to carbon market transparency.

Action Checklist

• Before purchasing carbon credits, obtain independent quality ratings from at least two rating providers (Sylvera, BeZero, or Calyx Global) and reject any credits rated below their second-highest tier
• Require project developers to provide satellite-verifiable monitoring data as a condition of any forward purchase agreement for nature-based credits
• Integrate ICVCM Core Carbon Principles criteria into internal procurement policies, specifying CCP-labeled credits as the default purchase standard
• Implement portfolio-level credit quality tracking with quarterly re-assessment to identify degradation in project performance or rating downgrades
• Establish internal expertise on baseline methodology by training at least one team member in VCS and Gold Standard quantification approaches
• For organizations with annual credit purchases exceeding $1 million, negotiate API access to a ratings platform for real-time quality screening during procurement
• Develop a written due diligence protocol covering additionality, permanence, leakage risk, and co-benefit verification for every credit purchase above $100,000
• Monitor regulatory developments including the EU Green Claims Directive and SEC climate disclosure rules for implications on carbon credit use in public claims

FAQ

Q: How reliable are carbon credit ratings from companies like Sylvera and BeZero? A: Independent carbon credit ratings have improved significantly since 2021 but remain imperfect. Satellite-based biomass estimation for forest projects achieves plus or minus 15% accuracy at the project level, which is substantially better than traditional self-reported estimates but still carries meaningful uncertainty. Ratings diverge across providers for approximately 20 to 30% of assessed projects, similar to the divergence rates observed among ESG rating agencies. Best practice is to consult multiple providers and investigate any project where ratings disagree by more than one tier.

Q: What drove the voluntary carbon market downturn, and is the market recovering? A: The 2023 to 2024 downturn was primarily triggered by investigative reporting questioning the integrity of REDD+ forest credits, which represented approximately 30% of market volume. Corporate buyers paused purchases pending clarity on quality standards. By mid-2025, market volume began recovering as the ICVCM's CCP framework provided a credible quality benchmark and buyers shifted toward higher-integrity project types including engineered carbon removal (direct air capture, biochar) and projects with third-party ratings. Ecosystem Marketplace projects the VCM will reach $3.5 billion to $5 billion in annual volume by 2028 if integrity standards hold.

Q: Should companies invest in carbon credits or prioritize internal emissions reductions? A: The science-based targets framework and leading voluntary standards are clear: internal abatement should be prioritized, with credits used only for residual emissions that cannot be eliminated through operational changes. Companies claiming net-zero status using primarily offset credits face growing regulatory and reputational risk. The recommended approach is to set science-based reduction targets for Scope 1, 2, and 3 emissions, invest in abatement measures with positive financial returns first, and use high-integrity carbon removal credits for genuinely hard-to-abate residual emissions.

Q: How is the regulatory landscape changing for carbon credit claims? A: The EU Green Claims Directive, expected to take effect in 2026, will require companies to substantiate any environmental claims, including carbon neutrality claims based on offsets, with verified evidence and approved methodologies. The US Federal Trade Commission is updating its Green Guides for the first time since 2012, with draft language specifically addressing carbon offset claims. France's Loi Climat already prohibits advertising claims of carbon neutrality unless supported by a verified lifecycle assessment and a credible reduction trajectory. These regulations collectively make credit quality documentation a legal compliance requirement rather than a voluntary best practice.

Sources

• Ecosystem Marketplace. (2024). State of the Voluntary Carbon Markets 2024: Market Contraction, Quality Convergence, and the Path Forward. Washington, DC: Forest Trends.
• The Guardian, Die Zeit, and SourceMaterial. (2023). Revealed: More Than 90% of Rainforest Carbon Offsets by Biggest Certifier Are Worthless. The Guardian, January 18, 2023.
• Integrity Council for the Voluntary Carbon Market. (2024). Core Carbon Principles Assessment Framework: Methodology and Implementation Guide. London: ICVCM.
• West, T. A. P., Börner, J., Sills, E. O., and Kontoleon, A. (2023). Action Needed to Make Carbon Offsets from Forest Conservation Work for Climate Change Mitigation. Science, 381(6660), 873-877.
• Sylvera. (2025). Carbon Credit Ratings Methodology: Technical Documentation v3.2. London: Sylvera Ltd.
• Xpansiv. (2024). CBL Market Intelligence Report: Environmental Commodity Trading Volumes and Price Discovery. San Francisco: Xpansiv Market LLC.
• European Commission. (2024). Proposal for a Directive on Substantiation and Communication of Explicit Environmental Claims (Green Claims Directive). Brussels: European Commission.
• BeZero Carbon. (2025). Voluntary Carbon Market Integrity Report: Rating Trends and Market Quality Indicators. London: BeZero Carbon Ltd.