Scope 1 Emissions under the GHG Protocol

Updated March 25, 2025 06:42

In carbon accounting, Scope 1 emissions refer to the direct emissions resulting from sources owned or controlled by a company, as outlined in the Greenhouse Gas (GHG) Protocol, the world’s leading standard for carbon accounting.

What exactly are ‘Direct Emissions’?

Scope 1 emissions include direct emissions from sources owned or operated by the company. According to the GHG Protocol, these emissions are grouped into four main categories:

Mobile Combustion

Mobile combustion involves burning fuels for transportation in vehicles or machinery owned or controlled by the business, such as cars, trucks, trains, and ships. Essentially, if it moves because it’s burning fuel, it counts as mobile combustion.

Some examples include:
- Company-owned vehicles (cars, trucks, buses)
- Machinery used in operations (such as in mining or construction)
Stationary Combustion

Stationary combustion refers to burning fuels for stationary equipment or processes, releasing emissions like carbon dioxide, methane, and nitrous oxide. Unlike mobile combustion, stationary combustion involves equipment that doesn’t move, such as boilers or generators in a fixed location.

For instance:
- Commercial kitchens using LPG for cooking
- Industrial furnaces or heating systems
Fugitive Emissions

Fugitive emissions come from the unintended release of gases, such as refrigerants in air conditioning units or leaks in industrial equipment. These emissions can be a surprising source of greenhouse gases, as equipment like fridges and A/C units often release small amounts of gases over time.

Examples include:
- Leaks from refrigeration and air conditioning
- Methane releases from coal mining and gas extraction
Process or Chemical Emissions

Process emissions occur when raw materials undergo chemical transformations, such as during cement or aluminium production. These emissions are typically associated with specific industries like oil and gas, metals, and cement manufacturing.

Examples include:
- Emissions from cement production
- Emissions during metal smelting and refining

Where is the data usually found?

Here’s a summary table for each Scope 1 emissions category, with common sources of activity data to help businesses locate the necessary information for accurate carbon accounting:

Scope 1 Emissions Category	Description	Common Sources of Activity Data
Mobile Combustion	Emissions from fuel used in vehicles or mobile equipment owned or controlled by the company (e.g., cars, trucks, buses, machinery)	Fuel purchase logs or receipts Vehicle mileage or odometer readings Fuel card statements Fleet management software records
Stationary Combustion	Emissions from fuel burned in stationary equipment, such as boilers, furnaces, and heating systems	Fuel purchase invoices Utility bills (for on-site heating systems) Maintenance logs for stationary equipment On-site meter readings (if applicable)
Fugitive Emissions	Emissions from leaks or releases of gases from equipment like refrigerators, air conditioning units, and industrial equipment	Refrigerant purchase and maintenance records Inspection and leak detection reports Service records for HVAC or cooling systems Inventory of refrigerant types and quantities
Process or Chemical Emissions	Emissions from chemical reactions in manufacturing processes, such as cement production, metal smelting, or refining	Production output records Raw material consumption logs Process-specific monitoring equipment Industry-specific emissions factors and calculations

Key Takeaway

Most businesses have some activities that contribute to Scope 1 emissions, whether through transportation, heating, cooling, or specific industrial processes. By measuring Scope 1 emissions, companies can understand their direct environmental impact and identify opportunities to reduce these emissions.

Want to explore Scope 1 emissions and carbon accounting further? Dive into the Introduction to Carbon Accounting course in the Sumday Academy to get a full picture of the methods available under the standards and where to find this data.