Scope 3 Carbon Software: Verification League Table (2025)

Scope 3

Alex Rudnicki

COO

4 min read

Table of contents

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Who passes independent verification, and who doesn't (yet).

This league table focuses only on third-party verification/validation of software methodologies used to calculate Scope 3 emissions. No points for "audit-ready," security certs, or corporate inventory verifications.

Scoring Rules (Simple and Fair)

Verified (✓): Public third-party statement covering the software/methodology, naming the verifier and assurance level (ISO 14064-3 or ISAE 3000/3410).
No Public Verification (–): No public software-level statement found.
Notes: Include the statement date/version so readers can check recency.

The Table

✓/–	Vendor	Product or module	Standard / level	Verifier	Evidence	Assurance date

✓	DitchCarbon	DitchCarbon Portal (Sustainability Information Calculator)	ISO 14064-3 (Limited assurance) - Verification Opinion Declaration; plus UL Solutions 'Sustainability Information Calculator Verification'	UL Solutions	UL Solutions Verification Opinion Declaration (June 6, 2025) & program verification (June 10, 2025)	June 10, 2025
✓	CarbonChain	Corporate & product footprint methodologies	Validated/verified as aligned with GHG Protocol	SGS (validation), Bureau Veritas (verification)	https://www.carbonchain.com/blog/carbonchain-methodology-receives-third-party-verification	-
✓	Lune	Carbon calculation tool	Verified against applicable clauses of ISO 14064-1	Interface NRM Ltd	https://docs.lune.co/lune-climate-iso14064-verification-statement.pdf	-
✓	Persefoni	GHG accounting methodology (software)	ISO 14064-3 (Limited assurance) - methodology validation only (excludes corporate inventory)	Apex Companies	https://persefoni-production.s3.us-east-2.amazonaws.com/docs/GLG_Persefoni_Independent_Validation_Statement.pdf	-
✓	Watershed	Carbon Data Engine	ISO 14064-3 (Limited / 'moderate' assurance)	Apex Companies (independent validation)	https://storage.googleapis.com/tech-docs-watershed/Watershed-Validation-Statement-20231127.pdf	-
–	CO2 AI (BCG)	Corporate & product footprinting	States adherence to PACT/PEF/ISO 14067/14044; SOC 2 & ISO 27001 (security)	-	https://www.co2ai.com/blog/co2-ai-unveils-the-first-solution-to-compute-product-footprints-at-scale	-
–	Carbon Interface	Emissions API	-	-	No public software level assurance statement found (as of 2025-10-12)	-
–	Climatiq	Emission factors & API	States 'scientifically vetted' emission factors; methodology hub	-	https://www.climatiq.io/methodology	-
–	EcoVadis	Ratings & Carbon Action Module	External methodology committee review (not formal assurance)	External committee (advisory)	https://support.ecovadis.com/hc/en-us/articles/115002531507-What-is-the-EcoVadis-methodology	-
–	Gravity Climate	Carbon & energy management platform	Positions as 'audit friendly'; customers pass audits	-	https://www.gravityclimate.com/blog/june-2025-product-updates	-
–	IBM (Envizi)	Envizi ESG Suite	-	-	https://www.ibm.com/products/envizi	-
–	IBM EIS GHG APIs	Environmental Intelligence Suite - GHG APIs	-	-	No public software level assurance statement found (as of 2025-10-12)	-
–	Manufacture 2030	M2030 Platform	-	-	No public software level assurance statement found (as of 2025-10-12)	-
–	Normative	Carbon Accounting Methodology	-	-	No public software level assurance statement found (as of 2025-10-12)	-
–	OpenCO2 (CO2API)	Emission Factors API	-	-	No public software level assurance statement found (as of 2025-10-12)	-
–	Plan A	Platform & Methodology	-	-	No public software level assurance statement found (as of 2025-10-12)	-
–	SAP	Sustainability Control Tower	-	-	https://www.sap.com/products/sustainability-control-tower.html	-
–	Sphera SCS (formerly SupplyShift)	Supply Chain Sustainability (SCS)	-	-	https://sphera.com/solutions/supply-chain-transparency/supply-chain-sustainability-solution/standard-assessments/	-
–	Sweep	Carbon Management Platform	-	-	No public software level assurance statement found (as of 2025-10-12)	-
–	Workiva (Sustain.Life)	Carbon / ESG Platform	-	-	No public software level assurance statement found (as of 2025-10-12)	-

Transferable Questions for Any Vendor

Scope: Does the statement explicitly cover the methodology or calc engine?
Level: Limited or reasonable? Any exclusions?
Versioning: Which release is covered, and how are updates handled?
Verifier: Who did the work, and are they accredited/recognized?

What This Means for Buyers

Use the league table during shortlisting and RFPs. Require links to assurance statements and keep copies with your audit evidence. When a vendor updates factors or logic, request updated assurance scope notes or a fresh statement.

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