Defining Scope 1, 2 and 3 Emissions

Two people in hard hats and reflective vests are talking outside, near industrial equipment, under a caption "Defining scope 1 2 3 emissions."

As environmental challenges increase, it has become crucial for individuals, businesses and governments alike to take responsibility for their carbon emissions. To tackle this issue effectively, emission measurements have been categorized into three distinct scopes: scope 1, scope 2 and scope 3.

Understanding how greenhouse gasses are emitted into the atmosphere is important to helping us find adequate solutions to reduce our carbon footprint. In this article, you’ll learn what each of these scopes is, what they encompass and why accurate measurement of them is essential for a sustainable future.

What are Greenhouse Gas Emissions?

Greenhouse gas (GHG) emissions are the gasses emitted to the atmosphere that intensify the greenhouse effect that warms the planet. Although the greenhouse effect is a natural process, human activities, such as the burning of fossil fuels, deforestation and industrial processes, have significantly increased the concentration of GHGs in the atmosphere, leading to accelerated global warming.

The World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) worked together to develop a protocol called the GHG Protocol to establish standardized frameworks for measuring and managing greenhouse gas emissions. It addresses the measurement and reporting of seven greenhouse gasses that are included in the Kyoto Protocol:

  • Carbon dioxide (CO2)
  • Methane (CH4)
  • Nitrous oxide (N2O)
  • Hydrofluorocarbons (HFCs)
  • Perfluorocarbons (PCFs)
  • Sulfur hexafluoride (SF6)
  • Nitrogen trifluoride (NF3)
What is the Difference Between Scope 1, 2 and 3 Emissions?
Scope 1 Emissions

Scope 1 are direct emissions from sources that are owned or controlled by an organization. Examples of scope 1 emissions include:

  1. On-Site Power Generation: Power generation systems, such as diesel generators, emit carbon dioxide (CO2) and other pollutants directly into the atmosphere.
  2. Heating and Cooling: Fossil fuel combustion for heating and cooling purposes, such as through natural gas boilers or chillers, lead to direct emissions of CO2.
  3. Chemical Refrigerants: Fugitive emissions from the release of refrigerants used in cooling systems, such as hydrochlorofluorocarbons (HCFCs) or hydrofluorocarbons (HFCs).
Scope 2 Emissions

Scope 2 emissions refer to indirect emissions associated with the generation of purchased electricity, heating, and cooling. These emissions are not directly controlled by the organization but result from the consumption of energy purchased from external sources, such as utilities or suppliers. Common sources of scope 2 emissions include:

  1. Grid Electricity: The emissions associated with electricity generation. The magnitude of these emissions depends on the energy mix of the local grid, which can include fossil fuels (coal, natural gas), nuclear, renewables (solar, wind, hydro) and other sources.
  2. Power Purchase Agreements (PPAs): The agreements to purchase electricity directly from renewable energy sources, such as wind farms or solar installations generate lower emissions, and can result in lower scope 2 emissions compared to the grid.
  3. District Heating and Cooling: Using district heating or cooling systems that rely on energy generated by another entity.
Scope 3 Emissions

Scope 3 emissions represent the broadest and most challenging category to measure and manage. These emissions are indirect and result from activities both up and downstream of the organization, including suppliers, customers, and end-users. Scope 3 emissions often account for the largest portion of an organization’s carbon footprint and may include:

  1. Supply Chain Emissions: Emissions from the production and provision of equipment, materials, and services, such as servers, networking equipment, and construction materials.
  2. Waste Management: Emissions generated from waste disposal and treatment processes, such as landfill gas emissions.
  3. Water Usage: Potable water requires much upstream processing, which uses a significant amount of energy – this results in upstream scope 3 emissions.
  4. Customer Emissions: The energy and resources consumed by customers, including cloud service users and tenants.
  5. Business Travel: Emissions from employee travel, including air travel, commuting, and other transportation-related activities.
Scope 1, 2, and 3 Emissions Diagram

In sum, scope 1 emissions are the ones we have direct control over. Scope 2 are the ones we have less control over, but are critical to our continuous operations. Scope 3 emissions are the ones furthest removed from our control, but likely represent the largest share of our total emissions.

Here is a diagram to better illustrate the difference between scope 1, 2, and 3 emissions:

Diagram showing the examples of Scope 1, scope 2, and scope 3 emissions.
Why Scope 1, 2 and 3 Emissions Matter

The categorization of GHG emissions is important in understanding the sources and complexities of these emissions, and creating thoughtful strategies for mitigation. By calculating their scope 1, 2, 3 emissions, organizations can identify opportunities for emissions reductions and implement targeted innovation to address each of them, for example:

  • Operational changes, such as using cleaner fuels or improving energy efficiency will directly manage and reduce scope 1 emissions.
  • Choosing to purchase renewable energy or adopting energy-efficient technologies results in lower scope 2 emissions.
  • Supplier engagement, product design for sustainability, promoting sustainable consumption and other ESG efforts contribute to reducing scope 3 emissions.

Ultimately, the proactive approach to scope 1, 2 and 3 emissions is important so businesses can develop holistic sustainability strategies, reduce their carbon footprint, and contribute to a greener, more sustainable world.

How to Calculate Scope 1, 2, and 3 Emissions?

Calculating scope 1, 2, and 3 emissions involves a systematic process of identifying, measuring, and reporting greenhouse gas emissions associated with an organization’s activities.

The GHG protocol provides tools that can help businesses calculate and create a reliable, complete inventory of their greenhouse gas emissions.

What are Scope 4 Emissions?

Scope 4 emissions are “avoided” emissions. The World Business Council for Sustainable Development defines avoided emissions as the difference between GHG emissions that occur or will occur (the « solution ») and GHG emissions that would have occurred without the solution (that of the reference scenario).

Implementing scope 4 goes beyond measuring and reducing scopes 1 – 3. It requires us to think bigger, innovate and scale decarbonized products and services.

Learn more about scope 4 emissions.

Scope Emissions and the Data Center Industry

Efforts to reduce emissions in the data center industry are essential, given the industry’s growing energy demands and environmental impact. In this Data Center Conversations video, Nancy Novak, Compass Datacenters Chief Innovation Officer, discusses the importance of understanding and categorizing greenhouse gas emissions with data center expert, Bill Kleyman. The conversation emphasizes the need for industry professionals to consider these scopes to reduce their environmental impact, such as the implementation of sustainable solutions for concrete production and backup generators.

They take a deep dive into scopes 1, 2 and 3 emphasizing the interconnected nature of these scopes and exemplifying Compass’ sustainability practices, such as the use of on-site concrete batch plants, that reduce emissions by eliminating the need for long-distance transportation, and the use of technologies like CarbonCure to reduce cement content. The discussion also highlights a shift towards using biofuels in backup generators for data centers as a more sustainable alternative to fossil fuels. These and other sustainable practices are at the core of our ESG strategy. 

Learn more about Data Center ESG.