The global transition toward a net-zero economy has reached a critical juncture where the ability to accurately measure and account for carbon emissions is no longer a peripheral corporate social responsibility concern but a core requirement for international trade and regulatory compliance. In a recent high-level dialogue hosted by the Trading Thoughts series, Amy Brachio, former Global Vice Chair for Sustainability at EY and current leader of the Carbon Measures coalition, joined Professor Karthik Ramanna of the University of Oxford’s Blavatnik School of Government to outline a transformative vision for product-level carbon accounting. As Co-Chairs of the International Chamber of Commerce (ICC) Technical Expert Panel on product-level carbon accounting, Brachio and Ramanna are spearheading an initiative to move beyond static, average-based reporting toward a dynamic, ledger-based system that mirrors the rigor of global financial accounting.
The current landscape of carbon disclosure is characterized by significant fragmentation, with companies often forced to navigate a labyrinth of competing methodologies, industry-specific standards, and regional regulations. This lack of uniformity creates substantial administrative burdens and undermines the reliability of data used by investors, regulators, and procurement officers. The ICC’s Technical Expert Panel aims to address these challenges by developing a standardized framework that ensures carbon data is "decision-useful," enabling stakeholders to make informed choices that directly incentivize decarbonization across global value chains.
The Shift from Reporting to Accounting
A fundamental distinction highlighted by Professor Ramanna is the difference between carbon reporting and carbon accounting. While reporting often involves the external disclosure of high-level, aggregate data for annual sustainability statements, carbon accounting refers to the underlying, primary data generated at the facility or batch level. This information must be "dynamic" rather than "static," reflecting real-time changes in production processes, input sourcing, and energy efficiency.
For carbon accounting to be effective, it must be "incentive compatible." In economic terms, this means that the system must be designed so that every actor in the value chain—from raw material suppliers to end-product manufacturers—has a vested interest in providing truthful and accurate information. By establishing a standard similar to Generally Accepted Accounting Principles (GAAP) or International Financial Reporting Standards (IFRS), the ICC initiative seeks to create a "calculate once, use many times" environment. This would allow a factory to produce a single, verified carbon intensity figure for a product that satisfies the requirements of multiple customers and regulatory bodies, regardless of their geographic location or specific reporting format.
Overcoming Practical Challenges in the Global Supply Chain
One of the most significant hurdles to universal carbon accounting is the complexity of global supply chains, particularly the inclusion of small and medium-sized enterprises (SMEs). Large multinational corporations may have the resources to track their direct (Scope 1) and energy-related (Scope 2) emissions, but obtaining primary data from hundreds or thousands of upstream suppliers (Scope 3) remains a daunting task.
To address this, Brachio and Ramanna point to successful pilot programs that utilize the "80-20 rule," focusing on the most emission-intensive inputs. A notable case study involves Giti Tire, an Indonesian-based manufacturer and one of the world’s largest tire producers. Faced with the challenge of tracking emissions across a vast supplier network, Giti Tire identified four key inputs—carbon black, steel cord, synthetic rubber, and natural rubber—that accounted for approximately 65% of the tire’s weight and the vast majority of its embedded emissions.
By engaging with a small group of primary suppliers for these materials, Giti Tire was able to generate specific, batch-level primary data. This iterative process proved successful when the tire manufacturer presented the data to a major global automotive customer. The customer’s positive response created a "pull factor," encouraging Giti Tire to expand the program to more suppliers. This recursive cycle demonstrates how market demand from major buyers can drive the adoption of rigorous accounting standards down through the lower tiers of the supply chain.
The Regulatory Pull: CBAM and Product-Level Standards
The urgency of this work is underscored by a shifting global regulatory environment. Governments are increasingly moving away from voluntary disclosure toward mandatory product-level emission standards. The most prominent example is the European Union’s Carbon Border Adjustment Mechanism (CBAM), which imposes a carbon price on certain carbon-intensive goods imported into the EU.
CBAM represents a significant shift in trade policy, as it requires specific, primary data for batches of imported goods rather than relying on industry averages. Under such regulations, inaccurate data can lead to financial penalties or restricted market access. As other jurisdictions, including the United Kingdom and potentially the United States, explore similar border adjustments and product intensity standards, the need for a robust, auditable carbon accounting system becomes a matter of legal and financial necessity.
Professor Ramanna notes that when data is used for regulatory compliance or taxation, different standards of liability and assurance apply. Moving from "limited assurance" (a lower threshold typically used in voluntary sustainability reports) to "reasonable assurance" (the higher standard used in financial audits) is essential for building trust in the global carbon market.
The Innovation of the Carbon Ledger
At the heart of the ICC’s proposed framework is the concept of the "carbon ledger." Drawing inspiration from the 15th-century invention of double-entry bookkeeping by Luca Pacioli, the carbon ledger applies the principles of financial transparency to atmospheric chemistry. This system treats carbon emissions as a "cost" that must be tracked, allocated, and transferred through the value chain with the same precision as monetary transactions.
The carbon ledger performs three vital functions:
- Permanent Archiving: Once a direct emission is recorded at a facility, it is entered into the ledger. It cannot be "deleted" or ignored; it remains a liability until it is allocated to a specific output.
- Causal Allocation: The system requires that all emissions incurred by an entity be allocated to its products or services. This mirrors the "full costing" principle in finance, ensuring that no "orphan emissions" are left off the books.
- Incentive-Compatible Transfer: When a product is sold, its associated carbon "debt" moves with it to the buyer’s ledger. This creates an immediate incentive for the buyer to seek out suppliers with lower carbon intensities to reduce their own ledger liabilities.
This ledger-based approach aligns with the first law of thermodynamics—the conservation of mass and energy. By treating carbon as a physical reality that must be balanced across the global economy, the ledger system provides a scientific and economic foundation for decarbonization.
Economic Implications and the Path to Scaling
The broader goal of standardized carbon accounting is to "endogenize" emissions reduction into the global market. Historically, carbon emissions have been treated as an "externality"—a cost borne by society rather than the producer. By integrating carbon data into the core of business decision-making, the ICC initiative aims to make emissions reduction a competitive advantage.
Professor Ramanna, reflecting on the economic development of nations like India and China, emphasizes that carbon accounting must not be a barrier to poverty alleviation. Instead, it must provide a pathway for sustainable growth. As billions of people enter the global middle class, their demand for goods and services must be met by companies that are rewarded for low-carbon innovation.
The growth of US capital markets in the 20th century provides a historical parallel. The introduction of GAAP, mandated by the Securities and Exchange Commission (SEC), led to a massive increase in market scale by providing investors with comparable, reliable data. A similar "market effect" is expected in the green economy: as reliable carbon data becomes available, capital will flow more efficiently toward low-carbon projects, and entirely new industries centered on carbon management will emerge.
Conclusion: Unlocking Markets through Transparency
The work of the ICC Technical Expert Panel represents a vital step toward a future where a product’s carbon footprint is as visible and standardized as its price or its nutritional content. Amy Brachio likens the future of procurement to reading a protein bar label; just as a consumer looks at calories and protein, a procurement officer will look at quality, price, and carbon intensity.
By aligning market incentives with climate goals, the ledger-based carbon accounting system offers a pragmatic solution to one of the greatest challenges of the 21st century. It provides the tools for regulators to enforce smart policy, for companies to drive operational efficiency, and for the global trade system to remain a force for progress while operating within the planetary boundaries of the Paris Agreement. The ICC continues to invite feedback from global stakeholders through its website, ensuring that the final standards are inclusive of SMEs and applicable across all sectors of the global economy.
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