The Greenhouse Gas (GHG) Protocol is the most widely used international standard for measuring and reporting greenhouse gas emissions. It provides organizations with a consistent framework to quantify their carbon footprint, enabling better management of emissions and alignment with global climate goals.
Developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD), the GHG Protocol offers tools, guidelines, and methodologies that are foundational to climate programs worldwide, including corporate sustainability reporting and national emissions inventories.
Scope 1 emissions are direct greenhouse gas emissions from sources that are owned or controlled by an organization. These emissions occur as a direct result of the organization’s operations and are often the easiest to measure because they come from specific, identifiable sources.
Scope 1 is critical because it represents the emissions an organization has the most control over, such as the fuel used in its vehicles or the combustion processes in its facilities. Managing Scope 1 emissions often involves upgrading equipment, improving fuel efficiency, or switching to renewable energy sources.
Common sources include fuel combustion in company-owned vehicles like trucks, cars, or forklifts, on-site fossil fuel use in boilers, furnaces, or generators, emissions from manufacturing processes such as cement production or chemical reactions, and fugitive emissions from leaks in refrigeration systems or pipelines, like methane or refrigerants.
Why it matters: Scope 1 emissions are often a significant portion of an organization’s carbon footprint, especially for industries like manufacturing, transportation, or energy production. Reducing these emissions can lead to immediate environmental and cost-saving benefits.
How to measure: Organizations track Scope 1 emissions by monitoring fuel consumption, equipment usage, and process outputs. Data is typically collected through meters, fuel purchase records, or emissions testing, and then converted to CO2-equivalent emissions using standardized factors provided by the GHG Protocol.
Challenges: Measuring fugitive emissions or emissions from complex processes can be difficult, requiring specialized equipment or expertise. Additionally, organizations with diverse operations may need to aggregate data from multiple sites.
Scope 2 emissions are indirect greenhouse gas emissions associated with the purchase of electricity, steam, heating, or cooling consumed by an organization. These emissions occur at the point of energy generation, such as at a power plant, rather than at the organization’s facilities, but they are attributed to the organization because it uses the energy.
Scope 2 is important because energy consumption is a major contributor to an organization’s carbon footprint, particularly for office-based or service-oriented businesses. Reducing Scope 2 emissions often involves improving energy efficiency or sourcing renewable energy.
Typical sources include emissions from electricity used to power office buildings, data centers, or factories, emissions from purchased steam for industrial processes, and emissions from district heating or cooling systems used in corporate facilities.
Why it matters: For many organizations, Scope 2 emissions represent a significant portion of their environmental impact. Transitioning to renewable energy sources, such as solar or wind, can drastically reduce Scope 2 emissions and align with sustainability goals.
How to measure: Scope 2 emissions are calculated based on energy consumption data, such as kilowatt-hours of electricity, and emissions factors specific to the energy source or grid. The GHG Protocol provides two methods for Scope 2 reporting: location-based, reflecting the average emissions intensity of the grid, and market-based, reflecting emissions from specific energy contracts, like renewable energy certificates.
Challenges: The accuracy of Scope 2 calculations depends on reliable energy data and up-to-date emissions factors, which can vary by region or supplier. Additionally, organizations may struggle to access renewable energy in some markets.
Scope 3 emissions encompass all other indirect greenhouse gas emissions that occur in an organization’s value chain, excluding Scope 2. These emissions are the most expansive and complex to measure because they include activities outside the organization’s direct control, such as supplier operations, product use, and employee commuting.
Scope 3 is often the largest portion of an organization’s carbon footprint, particularly for businesses with extensive supply chains or products that consume energy during use. Addressing Scope 3 emissions requires collaboration with suppliers, customers, and other stakeholders.
Key sources include emissions from raw material extraction and production by suppliers, emissions from business travel such as flights or hotel stays, emissions from employee commuting or teleworking energy use, emissions from the transportation and distribution of products like shipping or logistics, emissions from the use of sold products such as energy consumed by electronics or vehicles, and emissions from waste disposal or recycling of products at the end of their life cycle.
Why it matters: Scope 3 emissions can account for 70-90% of an organization’s total carbon footprint, especially in sectors like retail, technology, or consumer goods. Tackling Scope 3 is essential for achieving net-zero goals and demonstrating comprehensive climate leadership.
How to measure: Measuring Scope 3 emissions involves collecting data from suppliers, customers, and other value chain partners. The GHG Protocol categorizes Scope 3 into 15 distinct activities, and organizations use a combination of primary data, such as supplier reports, secondary data, like industry averages, and estimation models to calculate emissions.
Challenges: Scope 3 is notoriously difficult to measure due to its breadth and reliance on external data, which may be incomplete or inconsistent. Engaging suppliers to provide accurate emissions data and allocating emissions fairly across the value chain are ongoing challenges. Additionally, organizations must prioritize which Scope 3 categories are most material to their operations.