Part I - Scope 1. Straight to the Source: Measuring the full extent of Scope 1 emissions.

Part I - Scope 1. Straight to the Source: Measuring the full extent of Scope 1 emissions.

Scope 1 greenhouse gas emissions
Scope 1 emissions for GHGs

How to identify and account for the life cycle of scope 1 emissions.

This article is the first installment in a series about the greenhouse gas emissions (GHG) generated by companies and organizations. There are three types: scope 1, scope 2, and scope 3, as outlined by the Greenhouse Gas Protocol. Part 1 dives into scope 1 emissions, while Parts 2 and 3 will examine scope 2 and 3 indirect emissions respectively.

What is the scope system?

The scope system for identifying and measuring greenhouse gas emissions was developed by the Greenhouse Gas Protocol. This protocol provides a global framework for the management of GHG (greenhouse gases). It is applicable across both the private and public sectors, as well as in every step of the supply chain.

The Greenhouse Gas Protocol itself was established through a partnership between the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) (as well as other industry partners), with the first edition published in 2001. Thus, for over 20 years, the GHG Protocol, which has seen several updates since its inception, has assisted organizations as they calculate their GHG emissions and develop plans for more sustainable production, operation, and growth.

What is the point of tracking greenhouse gas emissions?

Greenhouse gases, which trap heat in the atmosphere, are emitted through natural processes and human activities. Since the Industrial Revolution, the concentration of greenhouse gases has increased dramatically, leading to rapid changes in climate.

These increasing concentrations of the greenhouse gases carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) and sulfur hexafluoride (SF6) all contribute to global warming.

In order to mitigate climate change, and align with the measures dictated by the 2015 Paris Climate Accord, companies must not only understand how much energy they are using, they must reduce it (and therefore, reduce their associated amount of GHG emissions) as well.

What are scope 1 emissions?

The Greenhouse Gas Protocol defines scope 1 emissions as direct GHG emissions released as a result of sources controlled by the company or organization. Examples of these emissions include but are not limited to:

  • Stationary Sources
  • Heating sources, such as boilers, furnaces, ovens etc.
  • Electricity if generated on-site and not purchased from third parties
  • Other facility operations, such as refrigeration and air conditioning
  • Non-stationary Sources
  • Fleet vehicle emissions from company owned and controlled vehicles (cars, vans, trucks, trains, etc.)
  • Construction equipment (if owned and controlled by the reporting company/organization).

Scope 1 emissions are also sector specific. As you can see in the list above, if construction equipment is owned and operated by the reporting company, then the company must include those emissions in its scope 1 measurements.

How do you measure scope 1 emissions?

There are different ways to measure your scope 1 emissions, and they are dependent on the source of the emissions, what sector you’re in, and the intent of your measurements.

For estimations or screenings, a simplified measurement is acceptable. Calculations for emissions from installation, operation, and disposal are provided by the GHG Protocol.

For detailed calculations of scope 1 emissions, more information is needed to satisfy reporting requirements. Examples of the types of information necessary include:

  • Fuel carbon content
  • Fuel heat content
  • Appropriate emission factors
  • Equipment capacity
  • Vehicle type
  • Fuel use/type
  • Distance traveled
  • Quantity of fuel combusted

One equation used to calculate scope 1 emissions includes knowledge of the actual carbon content of the fuel type used (however, most of the time this level of detail is not required). The equation is as follows:

Emissions = Fuel x CC x 44/12, where

Emissions = Mass of CO2 emitted

Fuel = Mass or volume of combusted fuel

CC = Fuel carbon content

44/12 = Molecular weight of CO2 to C

What can you do with scope 1 emission measurements?

Once you have calculated your organization’s scope 1 measurements, you can include them in your various environmental and sustainability reports.

You should also take steps to use that information to enact meaningful change in your organization. Scope 1 emissions are the easiest emissions to reduce because they are within your organization’s control. As you’ll see in Parts II and III, scope 2 and scope 3 emissions are often beyond your organization’s direct purview of influence. Scope 1, however, is more amenable to immediate action.

For more information about scope 1 emissions, the below references listed can be a good source of further detail.


EPA Center for Corporate Climate Leadership. (2020, December). Greenhouse Gas Inventory Guidance: Direct Emissions from Mobile Combustion Source. United States Environmental Protection Agency.

EPA Center for Corporate Climate Leadership. (2020, December). Greenhouse Gas Inventory Guidance: Direct Fugitive Emissions from Refrigeration, Air Conditioning, Fire Suppression, and Industrial Gases. United States Environmental Agency.

EPA Center for Corporate Climate Leadership. (2022, September 09). Scope 1 and Scope 2 Inventory Guidance. United States Environmental Protection Agency.

Greenhouse Gas Protocol. 2023. About Us. GHG Protocol.