By
Director of Climate Science & Impact
Published: 30 Mar 2025
30 min read
The voluntary carbon market plays an important role in corporate climate strategies – but its effectiveness relies on buyers doing due diligence and rigorous quality assessment on each project, as well as placing the purchase of credits in the right place in the climate journey. To ensure meaningful climate impact, businesses must develop a comprehensive carbon strategy and find ways to fund only high-quality credits in the voluntary carbon market – and this guide shows you how to do so with Ecologi.
When should businesses buy carbon credits in the voluntary market?
Businesses must not use credits in place of making direct, measurable reductions in their emissions. Instead, follow these steps to ensure you buy your carbon credits on the right step of your corporate climate action journey, and in the right way:
Measure your emissions first – to allow you to understand where your business’s emissions are coming from.
Set science-based targets and work towards them – set ambitious targets aligned with the SBTi and compatible with the global 1.5ºC warming target.
Beyond value chain mitigation (BVCM) – design your BVCM portfolio to work alongside your decarbonisation plan and address your unabated emissions in each reporting year. Align it with SBTi guidance and the Oxford Principles.
Buy high-quality carbon credits – use this guide to ensure the carbon credits you buy meet rigorous quality standards. Remember, under the SBTi framework you’ll also need permanent carbon removal credits for neutralising your residual emissions when you reach your net-zero date.
Disclose and report transparently – publicly disclose information about your carbon credit purchases, and clearly communicate the limited role of carbon credits in your broader sustainability strategy.
Ecologi’s carbon project assessment framework
In April 2025, we published a report summarising how we assess carbon credit projects against our rigorous proprietary rubric. A snapshot of what goes into our carbon credit project assessment is below, or you download the full whitepaper here.
Carbon project due diligence: Ecologi’s core principles
At Ecologi, we maintain general due diligence principles which we apply universally across the voluntary carbon market, to support our efforts to supply only high-quality carbon credits.
ICROA-endorsed standards only – we supply credits exclusively from carbon standards which are ICROA-endorsed.
Responsive to ICVCM decisions – we support the ICVCM’s two-tick approach to providing CCP-Approval to project methodologies, and we go further still, to assess individual projects on their merits and limitations as well.
Keep the carbon credit life cycle as short as possible – 75% of our credits in 2024 came directly from project developers and their nominated dispensaries (as opposed to intermediaries on the secondary market), maximising the proportion of purchase price which goes to the developer.
Locally-appropriate projects only – we take care to ensure that supported projects are being applied in appropriate geographies, where they can have the greatest impact.
Deep project-level scrutiny – our extensive assessment criteria are specific to each type of project, and we assess every project against these criteria, ensuring the project’s specifics have been taken into account.
Methodological consensus – we synthesise data we receive from our partners Sylvera, BeZero Carbon, Calyx Global and Renoster) with our own in-house analysis to uncover where there is consensus about project quality, and improve confidence.
How to evaluate carbon credits: Ecologi’s scoring methodology
We designed a three-layer assessment process which takes into account the merits and limitations of the carbon standard used, the carbon credit methodology used, and of the individual project design.The tables below summarise some of the data inputs we use at each stage.
Assessment level: Carbon Standard
Examples: Gold Standard, Verra, Puro Earth, Isometric, Plan Vivo.
Third party data inputs | Components included in the assessment |
|---|---|
ICROA endorsement | Independence, governance, registry, validation, transparency, environmental and social impacts, stakeholder impacts, scale. |
ICVCM CCP-Eligibility | Effective governance, tracking, transparency, robust independent third-party validation and verification, robust quantification of GHG emission reductions and removals, no double counting, sustainable development benefits and safeguards. |
Assessment level: Methodology (or ‘Protocol’)
Examples: GS TPDDTEC, VM0048, ACM0002.
Third party data inputs | Components included in the assessment |
|---|---|
ICVCM CCP-Eligibility | Additionality, Permanence assessment, robust quantification and appropriate baselines, no double counting, sustainable development benefits and safeguards, contribution to net-zero transition. |
Assessment level: Project
Examples: GS 10790, VCS 1571.
Third party data inputs | Components included in the assessment |
|---|---|
VVBs, e.g. Preferred By Nature | Validation: checking that the project meets the rules and requirements of the carbon standard. Verification: checking that the outcomes set out in the project design have been achieved |
Ratings agencies, e.g. Sylvera, BeZero Carbon, Calyx Global, Renoster | Various and extensive direct analysis from primary data. Such as carbon benefit analysis, additionality analysis, permanence analysis , co-benefits analysis, project developer integrity analysis. |
Risk indices, e.g. INFORM Risk Index. | Country-level risk analysis, and projections of crisis risk under different climate pathways |
GIS monitoring, e.g. Earth Blox. | Verification of project’s claims, and ongoing monitoring of project success over time. |
and are segmented by our three pillars of impact: Climate, Nature and People. Based on how it meets each criterion, the project gains points for quality criteria, and loses points for excess risk – ultimately giving a risk-adjusted value out of 100 for each of these pillars.
Having gathered our risk-adjusted pillar scores, we use our own unique scoring formula which weights the risk-adjusted Climate score of the project equally with the combined risk-adjusted Nature and People scores. The formula then produces an ‘overall’ score (also out of 100) for the project. In order to be supplied by Ecologi, projects must meet a minimum overall score of 80, and must achieve no lower than 65 in any given risk-adjusted pillar score.
Key questions to ask carbon credit suppliers
Selecting the right carbon credit provider is important to help guide you to make informed choices as part of your corporate sustainability strategy. Before purchasing carbon credits, businesses should ask:
Project quality
Do you assess/validate/underwrite project quality? If so, how?
Do your projects get good ratings from the ratings agencies? If so, what ratings are they?
Do you source credits directly from project developers, or from the secondary market?
Do you monitor projects over time to ensure continued success, and how do you remedy it, if a project’s quality drops?
Due diligence
How do you ensure you are supporting the right projects in the right locations?
How do you account for project permanence and mitigate risks?
What makes your projects additional?
How do you assess the project’s impacts on climate, nature and people?
Positioning
How do you contribute to the development of a high integrity voluntary carbon market?
Do you align your portfolios with the Oxford Principles? If so, how?
How do you reflect ICVCM guidance on carbon credit methodologies and technologies?
Do you build multi-year portfolios that align to mid- & long-term SBTs?
As the voluntary carbon market evolves, corporate buyers have the power and the responsibility to demand high-impact credits to drive real climate progress. This means buyers have a responsibility to do due diligence before placing an order for carbon credits.
