What Are Scope 1, 2, 3 Emissions?

A Companion to Understanding Carbon Accounting for Smarter Sustainability

In the journey toward net-zero, understanding where your carbon emissions originate is a crucial first step. Whether you're a sustainability officer at a construction firm, a procurement director, or a corporate decision-maker, grasping the concept of Scope 1, 2, and 3 emissions enables you to measure, manage, and reduce your climate impact more effectively.

What Are Greenhouse Gas (GHG) Emissions?

Greenhouse gases (GHGs) such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) trap heat in the Earth's atmosphere, driving global warming and climate change. To reduce their impact, organizations must first measure and categorize these emissions effectively.

This is where the GHG Protocol — a globally recognized framework — steps in. It classifies emissions into three scopes: Scope 1, Scope 2, and Scope 3.

Scope 1: Direct Emissions from Owned or Controlled Sources

Scope 1 emissions are the most direct and typically the easiest to measure. They come from sources that are owned or controlled by your organization.

Examples include:

• Fuel combustion in boilers, furnaces, or vehicles
• Emissions from generators on a construction site
• Process emissions from industrial facilities

Scope 2: Indirect Emissions from Purchased Energy

Scope 2 emissions refer to indirect emissions from the generation of purchased electricity, steam, heating, or cooling consumed by your organization.

Examples include:

• Electricity used in offices, factories, or construction trailers
• District heating or cooling purchased from a utility provider

Scope 3: Indirect Emissions Across the Value Chain

Scope 3 emissions are the broadest and most complex to manage. These include all other indirect emissions that occur throughout your value chain — both upstream and downstream.

Examples include:

• Business travel and employee commuting
• Extraction and transportation of raw materials
• Waste disposal and end-of-life product treatment
• Emissions from suppliers and subcontractors
• Use of sold products by customers