The GHG Protocol: The Global  Reference for Carbon Accounting

Key Takeaways: The GHG Protocol has established itself as the global reference for carbon accounting. By structuring emissions measurement through Scopes 1, 2, and 3, it now serves as the bedrock of international climate regulations. Adopted by 97% of S&P 500 companies, this standardized framework transforms reporting into a genuine strategic lever for environmental performance management. 

As ESG reporting frameworks converge toward increasingly harmonized international standards, mastering the GHG Protocol has become a strategic imperative. As a universal technical foundation, this standard allows organizations to navigate diverse regulatory requirements while ensuring rigorous carbon accounting.

You will discover how technical mastery of the three scopes ensures compliance for your non-financial reporting while structuring a sustainable, auditable decarbonization strategy recognized by the markets.

GHG Protocol: The Global Reference for Carbon Accounting

What is the  GHG Protocol ?

The most widely used international standard for carbon accounting is the GHG Protocol. Born from a collaboration launched in 1998 between the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD), it has become the indispensable norm.

Its mission goes beyond simple measurement: it establishes internationally accepted carbon accounting standards to guarantee consistency and transparency. It provides a rigorous framework for measuring, managing, and reporting emissions.

Adoption is massive: in 2023, 86% of S&P 500 companies relied on this standard for their CDP questionnaire response (or their CDP reporting).

Fundamental Principles for Reliable Reporting

La crédibilité d'un inventaire GES ne tient pas du hasard, mais du respect strict de cinq principes directeurs. Ils constituent le socle de confiance nécessaire à tout reporting sérieux et auditable.

The credibility of a GHG inventory does not happen by chance; it stems from strict adherence to five guiding principles. These constitute the foundation of trust necessary for any serious and auditable reporting. These rules ensure that data is not only accurate but also useful for decision-making:

• Relevance: The inventory reflects emissions and serves decision-making.
• Completeness: All emissions within the boundary are accounted for.
• Consistency: Stable methods to allow comparisons over time.
• Transparency: Clear and auditable information.
• Accuracy: The most precise quantification possible.

Greenhouse Gases Targeted by the Standard

The GHG Protocol remains focused; it targets high-impact gases governed by international agreements. This initial standard is logically based on the Kyoto Protocol to define its priority scope of action and ensure global compliance. To simplify analysis, all emissions are converted into a common unit: (CO₂e) equivalent (CO₂e).

• Carbon dioxide (CO₂)
• Methane (CH₄)
• Nitrous oxide (N₂O)
• Hydrofluorocarbons (HFCs)
• Perfluorocarbons (PFCs)
• Sulphur hexafluoride (SF₆)

Emissions Scopes: The Backbone of Reporting

Scope 1: Direct Emissions

Scope 1 covers direct GHG emissions. These originate from sources owned or controlled by the company. This is the tangible base of the carbon footprint. Reporting for this scope is mandatory.

This includes emissions from fuel combustion in boilers, furnaces, or company vehicles. Do not overlook fugitive emissions, which are often underestimated; air conditioning leaks, for instance, carry significant weight in this calculation.

Scope 2: Energy Indirect Emissions

Scope 2 covers indirect emissions related to the production of purchased energy consumed by the organization. This primarily concerns electricity, steam, heating, or cooling. Although these emissions physically occur outside the company, they result directly from its consumption. Responsibility, therefore, remains internal. Reporting is also mandatory for any serious organization.

Scope 3: The Challenge of Other Indirect Emissions

Scope 3 is the broadest and most complex category. It encompasses all other indirect emissions occurring in the company's value chain. It represents a major analytical challenge.

Long considered optional, its reporting is becoming a regulatory requirement for a growing number of companies. While technically complex, it is essential: it often represents the lion's share (and the most strategic portion) of the overall carbon footprint.

Beyond the Corporate Standard: A Complete Ecosystem of Norms

Limiting the GHG Protocol to corporate accounting alone would be a mistake. Its ambition is much broader, offering a range of standards adapted to different scales and activities.

The Corporate Standard

The GHG Protocol Corporate Accounting and Reporting Standard is the founding document. It is the reference guide consulted by multinationals, NGOs, and universities to establish their GHG inventory and structure their strategy.

It details how to define organizational boundaries (based on control or equity share) and operational boundaries, providing a rigorous framework for a true and fair account of emissions.

Standards for Products, Cities, and Projects

The protocol is not monolithic; it includes several specific standards to address distinct realities:

• The Product Standard allows for measuring the carbon footprint of a product over its entire life cycle. For manufacturers aiming for eco-design, this is a decisive tool for identifying real levers for action.

• On another scale, the GHG Protocol for Cities adapts the logic of scopes to urban territories.
  
  
• Finally, the Project Quantification Standard is designed to quantify emission reductions from specific projects, such as renewable energy initiatives.

Sector Guidance and Calculation Tools

To support the application of these standards, the GHG Protocol develops sector-specific guidance. These manuals offer more precise instructions for industries such as aluminum, cement, or pulp and paper.

Free calculation tools, often spreadsheets, are provided to apply the correct formulas. They reduce the complexity of the exercise and add credibility to the process, notably through the "Built on GHG Protocol" verification service.

A Strategic Lever for Corporate Climate Performance

Understanding the structure of the GHG Protocol is one thing. Grasping its concrete value for an organization is another. Far from being a mere accounting constraint, it is a genuine management tool. At ClimateSeed, our consultants are experts in this methodology and can guide you through both the measurement and the reduction of your carbon footprint.

Managing Risks and Identifying Opportunities

Ignoring one's carbon footprint means being blindly exposed to future financial penalties. The primary virtue of a GHG inventory lies in mastering risk management, whether regulatory (via carbon taxes) or physical (such as supply chain disruptions).

You cannot manage what you do not measure. The inventory highlights the most carbon-intensive areas, which often reveal energy inefficiencies or flagrant material waste within the value chain. This clarity allows for the immediate identification of opportunities for operational cost reduction and internal process optimization.

Developing a Credible Reduction Strategy

A rigorous inventory conducted according to the GHG Protocol constitutes the indispensable foundation for defining a solid climate strategy. Without this factual base, it is impossible to set a reliable base year or realistic quantified reduction targets.

The strength of this standard lies in its ability to make these objectives comparable and verifiable on a global scale. This methodological rigor builds the company's credibility in the face of increasing demands from investors, customers, and regulators.

Improving Transparency and Public Reporting

Opacity is no longer an option. The protocol provides a universal language to guarantee data transparency, enabling clear communication on real carbon performance. It has become a mandatory prerequisite for all public reporting, whether for voluntary sustainability reports or CDP responses.

Adopting this regulatory framework offers tangible benefits for non-financial reporting:

• Increased consistency of climate data across the group's various entities.
  
  
• Simplified reporting by avoiding the proliferation of complex proprietary formats.
  

Strengthened stakeholder trust in published information.

Integrating the Protocol into the International Regulatory Framework

This strategic value is now reinforced by growing institutional recognition. The GHG Protocol is no longer just a voluntary good practice; it is becoming the backbone of climate regulation.

Convergence with ISO Standards

This is an alignment that the market was expecting. In September 2025, a landmark partnership was formalized between the International Organization for Standardization (ISO) and the GHG Protocol. This alliance marks the end of standard fragmentation.

Experts hail this pragmatic decision, aimed at harmonizing rules with the ISO 14064 standard to co-build future frameworks. The goal is a single global language for carbon accounting, significantly reducing the administrative burden on companies.

A Reference for European and Global Regulations

The protocol's status has shifted from an option to the de facto standard for sustainability reporting. Regulators now rely on it to structure their requirements.

Look closely at recent texts. It is explicitly integrated into the European ESRS standards as well as the global standards of the ISSB (IFRS). Even California has adopted it in its climate laws. For these regulations, its use is often mandatory or strongly preferred.

Compatibility with Existing GHG Programs

The GHG Protocol was designed to be compatible with most GHG programs, whether voluntary or regulatory. It aligns with the EPA’s Climate Leaders program, WWF Climate Savers, and serves as a foundation for the EU ETS. This interoperability facilitates life for organizations subject to multiple regimes.

Looking Ahead: Major Evolutions of the GHG Protocol

Given its new status as a regulatory pillar and the climate emergency, the protocol is not static. A comprehensive update process is underway to address the challenges of tomorrow.

The Expected Revision of Scope 2

The GHG Protocol has launched a major public consultation regarding the Scope 2 Guidance. This process is instrumental in refining the accounting of renewable electricity. The primary objective is to ensure that market-based energy purchases result in a more accurate reflection of their climate impact.

While the proposal is expected to maintain the current dual reporting approach (location-based and market-based), it introduces more stringent requirements for temporal and geographical matching of energy certificates.

This evolution aims to strengthen the link between energy consumption and production, thereby reducing the risk of double counting and ensuring that green energy procurement drives real-world grid decarbonization.

The New Land Sector and Removals (LSR) Standard

The upcoming publication of the Land Sector and Removals (LSR) Standard (scheduled for 2026) marks a significant methodological shift. It integrates the land sector into the formal accounting framework, providing a standardized approach to measure both conventional emissions and carbon removals from land use and forestry.

This standard addresses a critical gap in carbon accounting by providing the necessary technical requirements for reporting removals. Its implementation is essential for organizations to accurately quantify their contribution to net-zero goals through land-based activities.

A Five-Year Update Process

These evolutions are part of a comprehensive global update of the standards. This structural overhaul will span five years and aims to modernize the entire accounting system.

Technical working groups have been established to revise all primary standards. They are specifically addressing the complexities of Scope 3 to align it with current requirements. The objective is to harmonize divergent methodologies, as maintaining consistency across the different scopes is paramount.

The final versions of the core standards are expected to be released in 2027 and 2028. Organizations should begin anticipating these milestones now to ensure a smooth transition.

Conclusion

The GHG Protocol has established itself as the essential foundation for any organization's climate strategy. Beyond mere accounting compliance, it provides a rigorous framework for driving decarbonization and anticipating future regulatory requirements. Mastering this standard is therefore a major competitive advantage for navigating an economy in the midst of a transition toward sustainability.