To understand scopes 1, 2, and 3, it’s important to first understand where these terms are commonly used in the sustainability space – greenhouse gas (GHG) inventories. More specifically, this terminology is used within the World Resources Institute’s GHG Protocol, acknowledged as the gold standard for calculating GHG emissions and most frequently used guidance on the planet. GHG inventories, also known as carbon footprints, are a comprehensive assessment of an organization’s share of impacts on the environment, specifically impacts associated with the release of greenhouse gases (i.e., carbon dioxide, methane, nitrous oxide, etc.) into the atmosphere. As there are multiple sources from which GHG gases originate, these emissions are categorized into three distinct scopes for several reasons – to provide consistency and clarity for reporting purposes as well as aim to minimize double counting by partner organizations.
Scope 1:
Scope 1 emissions are a critical component of a company’s carbon footprint as they are the only direct source of greenhouse emissions originating from sources under an entity's operational control. Think of scope 1 emissions as the foundational pillar, impacts of which a company is wholly responsible for. Scope 1 emissions vary widely based on the type of industry, but generally center around impacts associated with the company’s facilities and vehicle fleets.
Scope 1 emissions typically arise from activities such as on-site combustion of fossil fuels in stationary sources like boilers and furnaces, as well as from mobile sources like gas and diesel used in vehicles owned or operated by the company. Additionally, scope 1 emissions may include emissions from industrial processes and any onsite chemical reactions, including those generated by agricultural activities (i.e., enteric fermentation in livestock aka cow burps!).
Scope 2:
Scope 2 emissions refer to indirect greenhouse gases from the energy generation that a company purchases to run the company’s facilities and operations. To simplify the concept, these emissions are outside of the organization’s control, created by an external supplier, typically in the form of electricity, steam, heat, or cooling, and are necessary to run the company’s business.
The most common scope 2 emissions source is from purchased electricity that’s used in the company’s buildings, specifically the emissions caused by the generation of that electricity by the local power provider. Consequently, scope 2 emissions are often influenced by factors such as the energy mix of the local grid and the efficiency of energy generation technologies utilized by the company’s suppliers.
Scope 3:
Scope 3 emissions refer to all other indirect greenhouse gas emissions that occur within a company’s value chain, including both upstream and downstream sources that are not directly owned or controlled by the company. Essentially, scope 3 captures the full extent of a company’s carbon footprint, evaluating emissions across the entire lifecycle of its products and services, as well as capturing evolving and shifting business ventures. As we dig into the 15 categories, it’s clear that measuring and managing scope 3 often presents significant challenges due to the complexity of the supply chains required, the tracking capability of an organization, as well as the vast multitude of stakeholders that must be engaged in the process.
Scope 3 is broken into 15 categories to best classify emissions sources that are relevant and material to the company. Below is a snippet of what each of the 15 categories covers:
The following visual directly from the World Resource Institute’s GHG Protocol is extremely helpful in understand scopes 1, 2, and 3.
Source: WRI/WBCSD GHG Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard.