Why the GHG protocol categorises emissions in Scope 1, 2 and 3

TL;DR

The Greenhouse Gas (GHG) Protocol classifies emissions into Scope 1, 2 and 3 to ensure organizations measure their total climate impact in a consistent, complete and comparable way. Scope 1 covers direct emissions, Scope 2 covers indirect emissions from purchased energy, and Scope 3 includes all other indirect emissions across the value chain. This structure helps avoid double counting, improves accountability and supports targeted reduction strategies. Tools like the Atmoz carbon accounting engine simplify this process by automatically generating reports aligned with the GHG Protocol. Learn more about Atmoz carbon accounting solution.

Introduction: What is the GHG Protocol

The GHG Protocol is the leading global standard for greenhouse gas accounting. Developed by the World Resources Institute and the World Business Council for Sustainable Development, it provides guidance for companies and institutions to measure, manage and report their emissions.

It is used by organizations for sustainability disclosures, regulatory compliance, investor transparency and to set science-based targets. By categorizing emissions into Scope 1, 2 and 3, the GHG Protocol ensures clarity in reporting and helps companies understand their full climate footprint.

Read our full article about the GHG protocol here.

The basics of Scope 1, 2 and 3 emissions

This framework gives organizations a complete view of their emissions, from internal operations to upstream and downstream impacts.

Why the GHG protocol uses this classification

1. Ensures completeness in emissions reporting

Companies often underestimate their emissions when focusing only on their own facilities. By defining Scope 3, the GHG Protocol captures indirect emissions such as those from suppliers, business travel, waste and product use. This gives a realistic picture of the total climate impact.

2. Avoids double counting

The three-scope model helps assign responsibility without duplication. For instance, electricity generation is Scope 1 for a power producer and Scope 2 for the buyer. Scope 3 ensures upstream and downstream emissions are only reported by the organization most closely connected to them.

3. Supports targeted reduction strategies

Different scopes require different actions. Scope 1 can be reduced by operational changes. Scope 2 by switching to renewable energy. Scope 3 through supply chain collaboration. The framework helps companies prioritize where to act.

4. Aligns with global standards

Regulators and investors rely on the GHG Protocol as the foundation for reporting frameworks such as the Corporate Sustainability Reporting Directive (CSRD) and Science Based Targets initiative (SBTi). Using Scope 1, 2 and 3 ensures compliance with international expectations.

Practical example

Consider a global consumer goods company.

• Scope 1 emissions include fuel combustion from delivery trucks.

• Scope 2 covers electricity purchased for manufacturing sites and offices.

• Scope 3 includes emissions from raw material suppliers, international shipping, customer product use and packaging disposal among others.

Without the Scope 3 category, the company would miss over 80 percent of its emissions. The GHG Protocol ensures they recognize and report on their full impact.

The role of Scope 3 and why it is growing in importance

Scope 3 emissions typically represent the majority of an organization’s carbon footprint. In some industries, such as fashion or technology, Scope 3 can exceed 90 percent of total emissions.

As regulatory requirements evolve and investors demand more transparency, organizations must collect and report Scope 3 data to demonstrate comprehensive climate performance. Supply chain decarbonization and sustainable product design also depend on visibility into Scope 3.

This growing complexity is one reason why automated platforms like Atmoz’s carbon accounting engine are valuable. They streamline Scope 1, 2 and 3 data integration from internal and external sources, allowing for real-time insights and standardized reporting.

How Atmoz helps automate GHG protocol reporting

Atmoz offers a carbon accounting platform that automates data collection, calculation and reporting based on the GHG Protocol. Key features include:

• Automated classification of emissions into Scope 1, 2 and 3

• Built-in alignment with global standards including the GHG protocol

• Audit- and export-ready reports

This automation helps companies reduce time spent on manual data work while increasing accuracy and audit readiness. By using Atmoz Carbon Accounting engine, sustainability and finance teams can focus on climate action rather than spreadsheet management.

What are Scope 1, 2 and 3 emissions?

Why does the GHG Protocol separate emissions this way?

To ensure completeness, avoid double counting and support targeted emission reduction strategies. It also provides a clear standard for comparisons across companies and industries.

Is Scope 3 required for reporting?

While not always mandatory, Scope 3 reporting is increasingly expected by regulators and stakeholders, especially if it represents a significant portion of emissions.

Which scope is hardest to calculate?

Scope 3 is the most complex due to the need for external data from suppliers, partners and customers. Tools like Atmoz can simplify this process by automating supplier data integration.

Can I use Atmoz for regulatory reporting?

Yes. Atmoz aligns with the GHG Protocol.