GHG Protocol: Why Are Scope 1, Scope 2, and Scope 3 Carbon Emissions Different?

As climate change and environmental sustainability receive increasing attention, organizations are using a range of standards and tools to measure, report, and reduce their greenhouse gas emissions.

One of the most widely used frameworks is the Greenhouse Gas Protocol, commonly known as the GHG Protocol.

The framework classifies corporate greenhouse gas emissions into three categories:

• Scope 1
• Scope 2
• Scope 3

In this article, we explore what each scope represents, why emissions are divided into different categories, and how this classification helps companies develop more effective climate strategies.

What Is the GHG Protocol?

The Greenhouse Gas Protocol is a globally recognized framework for measuring and managing greenhouse gas emissions.

It was developed through a partnership between the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD).

The GHG Protocol provides companies, public institutions, cities, and other organizations with standardized methods for:

• calculating greenhouse gas emissions,
• defining organizational and operational boundaries,
• preparing emissions inventories,
• tracking performance over time,
• reporting climate-related data,
• identifying emission reduction opportunities.

It is important to distinguish the GHG Protocol from the Kyoto Protocol.

The Kyoto Protocol is an international climate agreement adopted in 1997. The GHG Protocol, by contrast, is an emissions accounting and reporting framework used by organizations to understand and manage their climate impact.

Under the GHG Protocol Corporate Standard, emissions are divided into Scope 1, Scope 2, and Scope 3.

This structure enables companies to understand emissions generated directly by their own operations as well as indirect emissions occurring across their wider value chains.

Why Does the GHG Protocol Divide Emissions into Three Scopes?

A company's climate impact extends beyond the fuel burned in its facilities or vehicles.

Emissions can also result from:

• purchased electricity,
• raw material production,
• transportation and logistics,
• employee commuting,
• business travel,
• product use,
• waste management,
• end-of-life treatment.

Separating emissions into three scopes helps companies determine:

• where emissions originate,
• how much control they have over each source,
• which departments or business partners should be involved,
• which reduction strategies are most appropriate,
• how emissions can be reported consistently.

Let us examine Scope 1, Scope 2, and Scope 3 emissions in greater detail.

What Are Scope 1 Emissions?

Scope 1 emissions are direct greenhouse gas emissions from sources that are owned or controlled by an organization.

These emissions are generated directly through the company's operations.

Examples may include emissions from:

• fuel burned in company-owned boilers or furnaces,
• company-owned or controlled vehicles,
• manufacturing equipment,
• industrial and chemical processes,
• refrigerant leaks from cooling systems,
• on-site electricity or heat generation.

Because these sources are owned or controlled by the company, the organization generally has a relatively high level of influence over them.

Examples of Scope 1 Emissions

A logistics company may generate Scope 1 emissions when diesel is burned in its vehicle fleet.

A manufacturer may generate direct emissions through fuel combustion, production processes, or refrigerant leakage.

An office-based business may have Scope 1 emissions from natural gas used for heating or fuel consumed by company vehicles.

How Can Scope 1 Emissions Be Reduced?

Companies can reduce Scope 1 emissions by:

• improving operational energy efficiency,
• electrifying company vehicles and equipment,
• replacing fossil-fuel-based heating systems,
• optimizing industrial processes,
• switching to lower-carbon fuels,
• preventing refrigerant leakage,
• improving maintenance practices.

Renewable energy can also support Scope 1 reductions when fossil-fuel-based systems are replaced with electrified alternatives powered by clean electricity.

What Are Scope 2 Emissions?

Scope 2 emissions are indirect emissions associated with the generation of purchased energy consumed by a company.

The emissions physically occur at the facility where the energy is produced rather than at the company's own site.

Scope 2 may include purchased:

• electricity,
• steam,
• heating,
• cooling.

For example, when a company purchases electricity from the grid, the power plant generating that electricity may burn fossil fuels and release greenhouse gases.

Although these emissions occur outside the company's facilities, they are associated with the energy the organization consumes.

How Can Scope 2 Emissions Be Reduced?

Companies can reduce Scope 2 emissions by:

• lowering electricity consumption,
• improving building and equipment efficiency,
• generating renewable energy on-site,
• purchasing renewable electricity,
• entering into renewable power purchase agreements,
• selecting lower-carbon energy suppliers,
• using credible energy attribute certificates where appropriate.

The GHG Protocol Scope 2 Guidance generally allows companies to report purchased electricity emissions using both location-based and market-based methods where applicable.

The location-based method reflects the average emissions intensity of the local electricity grid.

The market-based method reflects contractual electricity purchasing choices, such as renewable energy agreements or supplier-specific products.

What Are Scope 3 Emissions?

Scope 3 emissions include all other indirect greenhouse gas emissions occurring across a company's value chain.

These emissions are connected to the company's activities but arise from sources that the organization does not own or directly control.

For many companies, Scope 3 represents the largest share of their total carbon footprint.

Scope 3 emissions may occur both upstream and downstream.

Upstream Scope 3 Emissions

Upstream emissions occur before a company's own operations and may include:

• purchased goods and services,
• raw material production,
• capital goods,
• fuel- and energy-related activities,
• inbound transportation and distribution,
• operational waste,
• business travel,
• employee commuting,
• leased assets.

Downstream Scope 3 Emissions

Downstream emissions occur after products or services leave the company and may include:

• outbound transportation and distribution,
• processing of sold products,
• customer use of products,
• end-of-life treatment,
• downstream leased assets,
• franchises,
• investments.

For example, an electronics company's Scope 3 emissions may include emissions from raw material extraction, component manufacturing, product transportation, customer electricity use, and product disposal.

A food company's Scope 3 emissions may include agricultural production, packaging, cold-chain logistics, consumer use, and food waste.

How Can Scope 3 Emissions Be Reduced?

Reducing Scope 3 emissions usually requires collaboration across the value chain.

Companies can take action by:

• setting environmental requirements for suppliers,
• sourcing lower-impact materials,
• improving product durability,
• reducing packaging,
• designing products for repair and recycling,
• introducing refill and reuse systems,
• optimizing logistics,
• encouraging low-carbon employee travel,
• supporting suppliers in calculating their emissions,
• improving product energy efficiency,
• engaging customers in responsible use and disposal.

Because Scope 3 emissions sit outside a company's direct operational control, progress often depends on procurement policies, product design, supplier engagement, partnerships, and long-term sector-wide transformation.

Why Are Scope 1, Scope 2, and Scope 3 Emissions Different?

The three scopes differ primarily according to where emissions occur and how much control a company has over them.

Scope 1 emissions occur directly within a company's operational boundary.

Scope 2 emissions are linked to the electricity, heating, cooling, or steam purchased by the company.

Scope 3 emissions arise throughout the broader value chain, including suppliers, transportation providers, employees, customers, and product end-of-life processes.

Each category therefore requires different data sources, stakeholders, reduction measures, and management strategies.

Why Is It Important to Understand All Three Emission Scopes?

Understanding Scope 1, Scope 2, and Scope 3 emissions enables companies to see their full climate impact rather than focusing only on emissions generated within their own facilities.

This comprehensive perspective helps organizations:

• identify their largest emission sources,
• set science-aligned climate targets,
• avoid overlooking value chain impacts,
• improve procurement and product design,
• manage climate-related risks,
• prepare for reporting requirements,
• engage suppliers and customers,
• allocate resources more effectively.

A company may have relatively low Scope 1 emissions while generating substantial emissions through purchased materials or customer use of its products.

Without measuring Scope 3, the organization may overlook the majority of its carbon footprint.

Supporting More Effective Reduction Strategies

Dividing emissions into three scopes makes a complex greenhouse gas inventory easier to understand and manage.

For example:

• Scope 1 may require operational efficiency and electrification.
• Scope 2 may require renewable electricity procurement.
• Scope 3 may require supplier transformation and sustainable product design.

This classification allows organizations to develop targeted action plans while maintaining an integrated climate strategy.

Improving Transparency and Accountability

Reporting all relevant emission scopes gives stakeholders a clearer picture of a company's environmental performance.

It also allows companies to communicate their climate commitments with greater transparency and track progress over time.

However, companies should clearly explain:

• which emission sources are included,
• which calculation methods are used,
• which data limitations exist,
• whether estimates have been applied,
• how organizational boundaries have been defined.

Transparent reporting helps prevent misleading claims and makes performance comparisons more meaningful.

Building a Complete Corporate Carbon Inventory

Calculating emissions under the GHG Protocol requires companies to understand the activities that make up their entire value chain.

These may include:

• internal operations,
• energy consumption,
• production processes,
• product life cycles,
• procurement,
• suppliers,
• logistics,
• employee activities,
• customer use,
• waste and end-of-life management,
• investments and business partnerships.

This process can reveal where emissions are concentrated and which interventions are likely to create the greatest impact.

A complete greenhouse gas inventory provides the foundation for:

• setting a baseline year,
• establishing reduction targets,
• developing decarbonization road maps,
• tracking annual progress,
• communicating results,
• improving climate governance.

From Measurement to Climate Action

The climate crisis requires significant and urgent reductions in greenhouse gas emissions.

Classifying emissions as Scope 1, Scope 2, and Scope 3 helps companies break down a complex challenge into manageable areas and identify the most effective solutions for each one.

However, measurement alone does not reduce emissions.

The value of the GHG Protocol lies in how companies use the data to:

• improve operations,
• transform energy use,
• engage suppliers,
• redesign products,
• influence customer behavior,
• invest in lower-carbon solutions.

By measuring and managing all three scopes, companies can better understand their environmental impact and develop a more credible, comprehensive, and measurable climate strategy.