GHG Verification Statement: What It Includes & What Buyers Check

What Is a GHG Verification Statement?

A GHG verification statement (also called an assurance statement, verification opinion, or independent verification report) is a formal document issued by an independent third-party verification body that expresses an opinion on whether an organization's greenhouse gas emissions inventory is free from material misstatement. It is the final deliverable of a GHG verification engagement and the document that external stakeholders — investors, customers, rating agencies, regulators — rely upon to assess the credibility of reported emissions.

The verification statement is not a certificate. It does not certify that the organization has "passed" or met a threshold. Instead, it provides an independent professional judgment on whether the emissions inventory has been prepared in accordance with stated criteria (such as the GHG Protocol or ISO 14064-1) and is fairly presented in all material respects. Think of it as analogous to a financial audit opinion: the auditor does not guarantee the financial statements are perfect but provides reasonable or limited assurance that they are free from material errors.

The statement is addressed to the organization that commissioned the verification (the "responsible party") but is intended for use by third parties who rely on the emissions data. This dual audience — the reporting organization and its stakeholders — shapes both the content and the language of the statement.

Standard Structure of a Verification Statement

While there is no single mandated template, recognized verification standards (ISO 14064-3, ISAE 3000, ISAE 3410) establish the essential elements that every credible verification statement should contain. The following sections appear in virtually all well-structured statements.

1. Addressee

The statement is typically addressed to the board of directors, management, or designated sustainability officer of the reporting organization. Some statements are addressed more broadly — "To the stakeholders of [Company Name]." The addressee clarifies who commissioned the verification and to whom the verifier is accountable.

2. Scope of the Engagement

This section defines exactly what was verified. It should specify: the organizational boundary (which entities, facilities, or operations are included), the reporting period (e.g., January 1 to December 31, 2025), the greenhouse gases covered (typically all seven Kyoto Protocol gases), the emission scopes covered (Scope 1, Scope 2, Scope 3 — and if Scope 3, which categories), and the GHG inventory document that was subject to verification.

Clarity in scope is critical. A statement that says "we verified the company's carbon emissions" without specifying scopes, periods, and boundaries is essentially meaningless. Stakeholders should be able to determine exactly what the verifier examined and what was excluded.

3. Criteria

The criteria are the standards or frameworks against which the inventory was evaluated. Common criteria include: ISO 14064-1:2018, the GHG Protocol Corporate Standard, the GHG Protocol Scope 3 Standard, the EU Monitoring and Reporting Regulation (MRR) for EU ETS participants, or a combination of the above. The criteria section should also reference the GWP values used (e.g., IPCC AR5 or AR6) and any sector-specific guidelines applied.

4. Level of Assurance

The statement must explicitly state whether the engagement provided limited assurance or reasonable assurance. This distinction is fundamental — it determines the depth of work performed and the wording of the conclusion.

5. Responsibilities

The statement delineates responsibilities between the reporting organization (responsible for preparing the GHG inventory, maintaining internal controls, and selecting accounting policies) and the verification body (responsible for expressing an independent opinion based on the verification engagement). This separation is important because it makes clear that the organization owns its data — the verifier provides assurance on it.

6. Summary of Procedures Performed

This section describes the verification activities undertaken. For a limited assurance engagement, this typically includes: inquiry of personnel responsible for GHG data, analytical procedures (reasonableness checks, year-over-year comparisons, emission intensity benchmarking), review of documentation (methodology, emission factors, calculations), and limited testing of underlying data. For a reasonable assurance engagement, the procedures extend to: detailed testing of activity data against source records, recalculation of emissions for a sample of sources, site visits to verify data collection processes, assessment of internal controls over GHG data, and testing of emission factor selection and application.

7. Opinion or Conclusion

This is the most important element — the verifier's professional judgment. The wording differs based on the assurance level:

• Limited assurance (negative form): "Based on our limited assurance engagement, nothing has come to our attention that causes us to believe that the GHG statement is not prepared, in all material respects, in accordance with [criteria]."
• Reasonable assurance (positive form): "In our opinion, the GHG statement is prepared, in all material respects, in accordance with [criteria]."

The difference in wording reflects the different levels of confidence. A reasonable assurance opinion affirmatively states the inventory is fairly presented. A limited assurance conclusion states that nothing suggesting otherwise was found — a subtly but importantly weaker assertion.

8. Verifier Details

The statement includes the verification body's name, accreditation details, the lead verifier's qualifications, the date of the statement, and any independence declarations. Accreditation (e.g., under ISO 14065 by a national accreditation body) provides additional credibility that the verifier itself meets recognized competence standards.

Limited vs Reasonable Assurance: What's the Difference?

The choice between limited and reasonable assurance has significant implications for cost, effort, and stakeholder confidence.

Many organizations begin with limited assurance and progress to reasonable assurance as their data quality and internal controls mature. This phased approach is recognized and accepted by most reporting frameworks. CSRD, however, will require limited assurance initially and transition to reasonable assurance over time for sustainability reporting under ESRS, including GHG emissions.

How Buyers and Investors Read a Verification Statement

Sophisticated buyers, investors, and procurement teams have learned to read verification statements critically. Here is what they check — and why.

Scope Coverage

The first thing a knowledgeable reader checks is whether the verification covers all material scopes. A statement that verifies only Scope 1 and 2 when the supplier's Scope 3 represents 80 percent of its footprint provides limited assurance value. Buyers increasingly require Scope 3 coverage, at least for material categories, before accepting a verification statement as evidence of supply chain decarbonization commitment.

Assurance Level

Investors distinguish between limited and reasonable assurance. While limited assurance is widely accepted for Scope 3 and first-time reporters, investors expect reasonable assurance for Scope 1 and 2 from mature organizations. The trend is clearly toward reasonable assurance as the baseline expectation, particularly for companies in high-emitting sectors.

Verifier Credentials

Buyers check whether the verifier is accredited (under ISO 14065 or equivalent), whether the verifier has relevant sector experience, and whether there are potential independence concerns (e.g., the same firm provides consulting and verification services). Accredited verifiers are subject to oversight by national accreditation bodies, which provides an additional layer of quality assurance.

Materiality Threshold

Some verification statements disclose the materiality threshold used (e.g., 5 percent of total reported emissions). A lower threshold indicates more rigorous verification. If the threshold is not disclosed, sophisticated readers may question the depth of the engagement.

Qualifications or Emphasis of Matter

Any qualifications, adverse findings, or emphasis-of-matter paragraphs signal areas of concern. Buyers read these carefully to understand whether the issue affects the specific emissions data relevant to their procurement or investment decision.

What CDP and GRI Scorers Look For

CDP's scoring methodology treats verification as a key differentiator between companies at the Management and Leadership scoring levels.

CDP Verification Scoring Criteria

• Scope coverage: Verification of Scope 1 and 2 is expected at Management level. Scope 3 verification earns additional points toward Leadership level.
• Assurance level: Reasonable assurance scores higher than limited assurance. However, limited assurance is sufficient to meet minimum verification requirements.
• Verifier type: Accredited third-party verifiers score highest. Non-accredited but independent verifiers score lower. Internal verification scores lowest.
• Standard used: Recognized standards (ISO 14064-3, ISAE 3000, ISAE 3410) score higher than proprietary or unspecified standards.
• Consistency: The verification statement must cover the same reporting year and organizational boundary as the CDP submission. A mismatch between the verified period and the reported period is a common scoring penalty.

GRI 305 Expectations

GRI does not mandate verification for emissions disclosures, but GRI 2: General Disclosures recommends external assurance and requires disclosure of the assurance policy. When organizations report under GRI and provide verification, GRI expects the verification to cover all disclosed emission scopes and to use recognized standards. GRI readers check that the verification boundary matches the reporting boundary — a common discrepancy when organizations verify only certain facilities but report emissions for the entire group.

Good vs Weak Verification Statements

Not all verification statements are created equal. The difference between a strong and weak statement often lies in specificity and transparency.

Characteristics of a Strong Statement

• Clearly defined scope with specific scopes, categories, and organizational boundary named
• Explicit criteria reference (ISO 14064-1:2018, GHG Protocol Corporate Standard)
• Clear statement of assurance level (limited or reasonable)
• Detailed description of procedures performed
• Unambiguous opinion or conclusion using standard wording
• Verifier accreditation and lead verifier qualifications disclosed
• Independence declaration included
• Materiality threshold disclosed
• Emphasis-of-matter paragraphs where appropriate (e.g., noting reliance on estimation for Scope 3)

Characteristics of a Weak Statement

• Vague scope ("we reviewed the company's environmental data")
• No criteria reference or reference to internal/proprietary criteria
• Assurance level not stated or ambiguous
• Generic procedure descriptions ("we performed a desk review")
• No clear opinion — just a summary of findings without a conclusion
• Verifier credentials not disclosed or verifier is not independent
• Statement dated long after the reporting period
• No materiality threshold mentioned

A verification statement should answer five questions unambiguously: What was verified? Against what criteria? To what level of assurance? What did the verifier do? And what did the verifier conclude? If any of these are missing or vague, the statement's credibility is diminished.

Red Flags and Qualified Opinions

Stakeholders should watch for these red flags when reviewing verification statements.

Red Flag 1: Non-Independent Verifier

If the same firm that helped prepare the GHG inventory also issued the verification statement, there is an independence conflict. ISO 14064-3 and ISAE 3000 both require verifier independence. Readers should check whether the verifier provides any advisory, consulting, or preparation services to the same client.

Red Flag 2: Scope Exclusions Without Explanation

A statement that excludes Scope 3 or excludes certain facilities without explanation may indicate that the organization is cherry-picking what gets verified. While it is common and acceptable to verify Scope 1 and 2 before adding Scope 3, the exclusion should be disclosed and the reason stated.

Red Flag 3: Vague or Missing Criteria

A statement that does not reference a recognized standard (ISO 14064-1, GHG Protocol, ISAE 3410) as criteria raises questions about what the verifier actually assessed. Proprietary or undefined criteria make it impossible for readers to evaluate whether the verification was meaningful.

Red Flag 4: No Accreditation

While not all jurisdictions require accreditation, verifiers accredited under ISO 14065 by a recognized accreditation body have been independently assessed for competence, impartiality, and quality management. A non-accredited verifier may be perfectly competent, but the lack of accreditation removes an external quality check.

Understanding Qualified Opinions

A qualified opinion contains an "except for" clause indicating a specific area where the verifier could not obtain sufficient evidence or found a material misstatement. Qualifications are not necessarily fatal — they indicate transparency. Common reasons for qualification include:

• Scope limitation: The verifier could not obtain sufficient evidence for a specific emission source (e.g., a recently acquired facility with incomplete records).
• Material misstatement: A specific calculation error was identified that the organization did not correct before statement issuance.
• Criteria departure: The organization deviated from the stated criteria for a specific source (e.g., used a non-standard emission factor without justification).

An adverse opinion — where the verifier states that the inventory is materially misstated — is rare but serious. It indicates fundamental problems with the inventory that go beyond specific issues. A disclaimer of opinion — where the verifier cannot form any opinion due to insufficient evidence — is equally serious and suggests the engagement could not be completed meaningfully.

Practical Examples: Statement Language

The following examples illustrate the difference between strong and weak verification statement language.

Strong Conclusion (Limited Assurance)

"Based on our limited assurance engagement, nothing has come to our attention that causes us to believe that the GHG statement of ABC Corporation for the year ended 31 December 2025, comprising 12,450 tonnes CO₂e of Scope 1 emissions, 8,200 tonnes CO₂e of Scope 2 emissions (location-based), and 145,000 tonnes CO₂e of Scope 3 emissions (Categories 1, 3, 4, 5, 6, and 7), is not prepared, in all material respects, in accordance with ISO 14064-1:2018 and the GHG Protocol Corporate Standard."

This is strong because it names the company, the reporting period, the specific emission figures verified, the scopes and categories, and the criteria — all in the conclusion itself.

Weak Conclusion

"We have reviewed the company's environmental data and find it to be generally consistent with good practice."

This is weak because it does not specify: which company, which data, which period, which scopes, which criteria, or which level of assurance. It uses non-standard language ("generally consistent with good practice") that has no defined meaning in verification standards. A reader cannot determine what was verified or with what confidence.

Qualified Opinion Example

"In our opinion, except for the possible effects of the matter described in the Basis for Qualified Opinion paragraph, the GHG statement of XYZ Industries for the year ended 31 December 2025 is prepared, in all material respects, in accordance with ISO 14064-1:2018. Basis for Qualified Opinion: We were unable to obtain sufficient appropriate evidence regarding the reported Scope 3 Category 1 emissions of 45,000 tonnes CO₂e due to the unavailability of primary supplier data for recently acquired Subsidiary B. This amount represents approximately 15% of total reported Scope 3 emissions."

This qualified opinion is transparent: it identifies the specific issue, quantifies its potential impact, explains why the limitation occurred, and maintains an unqualified opinion on the remainder of the inventory.

Frequently Asked Questions