Accelerating Innovation with the E-ledgers Accounting Method

The E-ledgers Institute is a not-for-profit learning organization advancing rigorous emissions-accounting practices to drive innovation in energy efficiency worldwide.

We advance rigorous emissions-accounting practices to drive innovation in energy efficiency worldwide.

Our founders developed the E-ledgers method for accurately and reliably tracking emissions and removals across even the most complex of supply chains in as close to real-time as practicable. We help pioneering organizations pilot the E-ledgers method, disseminating insights from these pilots, including economy-wide standards for best practice, for the world to harness.

The E-ledgers method introduces a simple, verifiable, and comparable calculation for the incurred net emissions of any product, service, organization, portfolio, or jurisdiction.

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Who’s Piloting E-ledgers?

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Hitachi Energy

Hitachi Energy

In 2023, we partnered with Hitachi Energy and three tiers of their supply chain to analyze the E-liabilities of electrical transformers. The case study, published in November 2023, describes the counterintuitive insights from the copper supply chain and on cradle-to-gate emissions of Hitachi transformers discovered during the pilot. The accompanying video demonstrates how the Hitachi pilot calculated and analyzed the emissions data according to the E-liability method.

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BMW Group

BMW Group

Our most recent case study is with BMW Group, which piloted the E-liability approach on a highly customizable part of its iX range of electric cars: the radiator kidney grille. The pilot addresses a common challenge: working with suppliers who lack the capacity to calculate their embedded emissions. This article explores how BMW Group helped equip suppliers for direct emissions measurement and establish protocols to audit data at the source, ensuring data accuracy from the start.

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Tata Steel

Tata Steel

We partnered with Tata Steel, which is part of India’s largest conglomerate, the Tata Group, to analyze the carbon content of steel produced through various methods. The compelling element of the pilot is that Tata Steel was able to differentiate what is effectively a commodity product on emissions grounds by using product-level emissions accounting. The accompanying panel discussion dives deeper into the Tata Steel experience.

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Heidelberg Materials

Heidelberg Materials

Heidelberg Materials, one of the world’s leading cement producers, piloted the E-liability method focusing on a dominant contributor to cement-related emissions the conversion of limestone into clinker. By allocating real-time, batch-level emissions to cement products, the pilot demonstrated how accurate and verifiable emissions data can inform both operational decisions and customer choices.

Read Full Study

Hitachi Energy

Hitachi Energy

In 2023, we partnered with Hitachi Energy and three tiers of their supply chain to analyze the E-liabilities of electrical transformers. The case study, published in November 2023, describes the counterintuitive insights from the copper supply chain and on cradle-to-gate emissions of Hitachi transformers discovered during the pilot. The accompanying video demonstrates how the Hitachi pilot calculated and analyzed the emissions data according to the E-liability method.

Read Full Study

BMW Group

BMW Group

Our most recent case study is with BMW Group, which piloted the E-liability approach on a highly customizable part of its iX range of electric cars: the radiator kidney grille. The pilot addresses a common challenge: working with suppliers who lack the capacity to calculate their embedded emissions. This article explores how BMW Group helped equip suppliers for direct emissions measurement and establish protocols to audit data at the source, ensuring data accuracy from the start.

Read Full Study

Tata Steel

Tata Steel

We partnered with Tata Steel, which is part of India’s largest conglomerate, the Tata Group, to analyze the carbon content of steel produced through various methods. The compelling element of the pilot is that Tata Steel was able to differentiate what is effectively a commodity product on emissions grounds by using product-level emissions accounting. The accompanying panel discussion dives deeper into the Tata Steel experience.

Read Full Study

Heidelberg Materials

Heidelberg Materials

Heidelberg Materials, one of the world’s leading cement producers, piloted the E-liability method focusing on a dominant contributor to cement-related emissions the conversion of limestone into clinker. By allocating real-time, batch-level emissions to cement products, the pilot demonstrated how accurate and verifiable emissions data can inform both operational decisions and customer choices.

Read Full Study
Explore Case Studies

Launch of the Proto-Standard for Carbon Accounting

The E-ledgers Institute announced the release of a draft Proto-Standard for product-level emissions accounting and auditing using the E-liability method in September 2024. This innovative approach aims to transform how we account for emissions by tracking the cradle-to-gate emissions embedded in products and services as they move through the economy.

Our Proto-Standard

Core Conceptual Articles

Accounting for Climate Change

The first rigorous approach to ESG reporting

by Robert S. Kaplan and Karthik Ramanna

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The E-liability accounting system was introduced as the first rigorous approach to ESG reporting in an article co-authored by Professors Robert Kaplan and Karthik Ramanna and published in the Harvard Business Review (HBR). The article provides a detailed method for assigning “E-liabilities” across an entire value chain, and uses the example of a car-door manufacturer to demonstrate how this may work in practice. The article went on to win the 2022 HBR-McKinsey Award for “groundbreaking management thinking,” which in turn kicked off a series of pilot adoptions of the method by organizations around the world.

Harvard Business Review

November 2021

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Accounting for Carbon Offsets

Robust Reporting Principles to Improve Today’s Carbon-Trading Markets

 by Robert S. Kaplan, Karthik Ramanna, and Marc Roston

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Markets for carbon trading function poorly, and many traded offsets do not actually perform as promised. Without robust protocols for monitoring offsets and in the absence of proper accounting mechanisms, market-based approaches to reducing atmospheric GHG will be vulnerable to misrepresentation and fraud. Our co-founders offer E-assets as a solution, applying fundamental and well-established financial accounting principles to improve the measurement and reporting of carbon offsets. Published in the HBR, the article presents five core principles that define what constitutes an E-asset, when can such an offset be traded in arms’-length exchanges, when can the asset be used to extinguish emissions liabilities, and who bears responsibility for reporting offset impairments after the underlying assets are destroyed, for instance, due to fire or deforestation.

Harvard Business Review

July 2023

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Disclosing Downstream Emissions

When are companies accountable for customers’ use of their products?

by Robert S. Kaplan and Karthik Ramanna

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An increasing number of companies are using the E-liability carbon-accounting method as an important tool for tracking progress toward reducing global emissions in their supply chains. The system does not require formal accounting for downstream emissions – those occurring after a company sells its products to immediate customers, for several good reasons. Certain companies, however, are accountable for disclosing downstream emissions generated by consumers’ use of their products. This article presents three principles to govern accountability and explains how and to what standards of reliability the companies should disclose downstream emissions.

Harvard Business Review

July 2024

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Latest Publications and Media

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Standardizing Carbon Accounting Worldwide With a Single, Robust, Cost-Effective System

By Vincent Aussilloux, Yann Coatanlem, and Karthik Ramanna

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This Atlantic Council issue brief, co-authored by our co-founder Karthik Ramanna, argues that scaling climate finance and strengthening energy security require more rigorous and comparable carbon accounting. The authors call on members of the Climate Club to select a single robust, auditable, and cost-effective accounting framework, advancing ledger-based carbon accounting as a practical solution. The authors make the case that such a system would support credible carbon labeling, emissions-based trade measures, and more efficient climate finance.

Atlantic Council

February 2026

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Measuring the Carbon Footprint for Health Systems and Suppliers

A Collaborative Field Study by Providence Health System and Becton-Dickinson

by Robert S. Kaplan, Scott Hudson, Oriana Turley, Maureen Mazurek, and Beth Schenk

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The E-ledgers Institute partnered with Providence Health System (PHS) and Becton Dickinson to track the emissions from manufacturing and transporting seven high-volume syringes to three PHS hospital sites, and from their subsequent use and disposal. The study demonstrates how the E-liability approach, through supplier-specific data collection and causal allocation, enables more accurate product-level carbon accounting, revealing where health system emissions accumulate and opportunities to lower those emissions.

E-liability Institute

January 2026

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Join us on our mission to advance the urgent accounting upgrade needed to drive innovation in energy efficiency worldwide.

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