Carbon accounting is complex. The methodologies used to calculate emissions can vary significantly depending on carbon accountant, framework, or data source. And, while inconsistencies exist across all emissions factors, they are particularly problematic when it comes to Scope 3 emissions – the indirect emissions that occur across a company’s supply chain.

Scope 3 emissions typically represent the largest share of a company’s footprint – around 75% of total emissions on average. This, coupled with the voluntary nature of reporting for SMEs, means a significant gap exists in supply chain emissions reporting.

In short: the biggest share of emissions is the least reliable to measure.

There is also a distinct lack of harmonisation in approach. Current methods are often incomplete, inconsistent, and difficult to compare and data is collected in multiple formats, using different methodologies. This culminates in a fragmented landscape that burdens businesses with information that is rarely decision-useful.

Without reliable, comparable data:

• Businesses struggle to identify emissions hotspots and prioritise action
• Banks and corporates lack certainty around their supply chains when making financing decisions
• Governments and regulators face barriers to designing effective policy interventions because the underlying data is inconsistent or incomplete.

The importance of this high-quality carbon data is rapidly increasing too; becoming central to procurement decisions, taxation frameworks, cross-border adjustment mechanisms such as CBAM, and access to sustainable finance. And yet, the current data ecosystem is lagging behind this growing demand.

Transparent, unified and harmonised

CC was created to address this challenge. Instead of another competing standard, it will create a transparent, unified, and fit-for-purpose approach towards a harmonised methodology, and principles for calculating hybridised, system-complete, emissions factors.

If this can be accurately addressed, then the benefits could be far reaching, helping businesses manage supplier risk, tackle incoming regulatory pressures (TCFD, CSRD, CBAM, SECR), and allowing them to respond to stakeholder demands.

For SMEs, the impact could be particularly transformative. Through Perseus we’ve seen how reliable emissions data can help unlock access to sustainable finance. With its focus on Scope 3, CC could help SMEs streamline reporting requests from large customers, and provide a clearer pathway for them to participate in low-carbon supply chains.

Our approach

The solution to improving supply chain carbon accounting hinges on pre-competitive collaboration. CC facilitates this, alongside independent governance and oversight, ensuring outputs are practical, robust, comparable, and fit-for-purpose, while drawing on technical and academic expertise.

Membership

Joining CC offers organisations an opportunity to shape the future of supply chain emissions data. Benefits include:

• Helping shape a harmonised approach to emissions factors that is practical, scalable, and aligned with real-world business needs.
• Gaining early access to outputs (e.g. hybridised emissions factors) for integration into products, services, and reporting solutions.
• Staying ahead of regulatory change and influence alignment with standards, regulators, and policymakers.
• Gaining early insight into developments in carbon reporting, procurement requirements, and international mechanisms such as CBAM.
• Strengthening your organisation’s supply chain resilience and sustainability
• Supporting the creation of reliable, comparable data that enables better risk management and decision-making.

To find out more about membership and fees, reach out via cc@ib1.org

You can read the minutes of our latest Steering Group meeting here: https://ib1.org/2026/02/11/carbon-commons-steering-group-january-2026-minutes/

Carbon Commons (CC) is a new collaboration to improve supply chain carbon accounting. 

Today’s carbon accounting methods often rely on inconsistent and incomplete data, which can result in fragmented, incomparable, and often unrealistic emissions estimates across complex supply chains. CC will help create a transparent, unified, usable, and fit-for-purpose approach towards a harmonised methodology, and principles for calculating hybridised emissions factors. 

Role

The CC Steering Group, provides independent governance, oversight and direction by convening non-commercial stakeholders to guide and validate priorities and outputs. It will ensure delivery of fit-for-purpose reporting that is practical, realistic, robust, comparable, and complete. 

Date: 26 January 2026 10:00-12:00 GMT

Location: online

Co-Chairs: Gavin Starks (Icebreaker One) and Duncan Oswald (Sage, interim co-chair pre-launch)

Secretariat: IB1

Meeting Aims: 

1. Explain Carbon Commons and its governance processes
2. Discuss targets and launch ideas
3. Agree on Membership proposal and reach out to prospective members

Minutes:

• It was agreed that:
  • the governance model and membership terms be adopted
  • the vision, mission, and values be adopted, subject to the addition of ‘five principles’

• It was noted that:
  • for-profit organisations cannot sit on the Steering Group (n.b.  DO will step down as interim co‑chair and there will be a selection process for the new co-chair)
  • CC is positioned to aid harmonisation and compliance, not as a competing standard. The SG will determine its scope – e.g. data set(s), defining criteria for CC-compliant factors and methods, enabling comparability across products, companies and sectors.
  • the SG will approve a definition of ‘fit-for-purpose’ for CC
  • the role of technical and academic expertise is essential in safeguarding methodological quality 
  • governance is key to enable adoption and reduce risk
  • carbon accounting is increasingly important in procurement, taxation, cross-border adjustment mechanisms (CBAM), and financial decisions, but the data quality is not fit for purpose or system complete
  • product‑level emissions factors are an initial priority area for impact and alignment

• It was discussed that:
  • there is a need to coordinate with government and parallel initiatives (e.g. WRI, UK Government) to ensure incremental development and avoid duplication of effort
  • clear communication and storytelling are critical: CC participants must be able to understand and explain what it is and what it is not (e.g. via product-level use cases) in plain language, for practitioners, SMEs and related stakeholders

Next meeting: March 2026 [date to be confirmed]

Formal records, including attendees, are maintained by the secretariat.  These are confidential to the Steering Group Members.