As global climate commitments intensify, the ability of companies to measure, manage, and reduce greenhouse gas (GHG) emissions has become a defining element of corporate sustainability. The Greenhouse Gas Protocol (GHGP), developed by the World Resources Institute (WRI) and World Business Council for Sustainable Development (WBCSD), remains the most widely adopted framework for categorising emissions into Scopes 1, 2, and 3. In recent years, a fourth category, Scope 4 emissions, or avoided emissions, has emerged as a voluntary but increasingly recognized metric [1][2].

Understanding these categories is critical for companies not only to comply with regulatory requirements but also to identify opportunities for competitive advantage, particularly as stakeholders demand greater transparency. This article explores the distinctions among Scopes 1–4, the challenges of measurement, and the implications for business strategy and investor engagement.

Defining the Scopes of Emissions

Scope 1: Direct Emissions

Scope 1 emissions are those released directly from sources owned or controlled by a company. These include fuel combustion in company-owned vehicles, boilers, furnaces, and fugitive emissions from industrial processes such as cement production or petrochemical refining [1][2]. Because they fall within an organisation’s operational boundaries, Scope 1 emissions are typically the most straightforward to measure and manage.

Scope 2: Indirect Energy Emissions

Scope 2 covers emissions generated from purchased energy, such as electricity, steam, or heat. While the physical emissions occur off-site, at the power plant or other energy provider—they are attributed to the company consuming the energy [1]. For many companies, electricity purchases are among the largest contributors to emissions, making renewable energy procurement a key opportunity for rapid reductions [1].

Scope 3: Value Chain Emissions

Scope 3 encompasses all other indirect emissions across a company’s value chain, both upstream and downstream. These include supplier emissions, employee commuting, business travel, transportation and distribution, product use, and end-of-life treatment [1][2]. According to McKinsey, Scope 3 often represents 90% of a company’s total carbon footprint, though this varies by sector [2].

Scope 3 poses the greatest challenges for measurement and management, as emissions data must be gathered from suppliers, customers, and partners outside of a company’s direct control. To address these challenges, the GHGP Corporate Value Chain (Scope 3) Standard provides guidance on reporting across 15 categories of activities [3].

Scope 4: Avoided Emissions

Scope 4, sometimes described as “avoided emissions”, captures the potential reductions in emissions enabled by a company’s products or services. These reductions occur outside a company’s own value chain but as a result of its offerings. Examples include teleconferencing software that reduces business travel, low-temperature detergents that save energy, or energy-efficient appliances that lower electricity consumption [4][5].

Unlike Scopes 1–3, Scope 4 is voluntary and not part of the GHGP’s formal accounting framework. While it provides a way for companies to demonstrate climate-positive contributions, Scope 4 disclosures are often viewed cautiously by stakeholders due to risks of greenwashing if reported without transparency or alongside incomplete Scope 1–3 disclosures [4].

Comparison of Scope Categories

Scope	Definition	Examples	Control Level	Reporting Status
Scope 1	Direct emissions from sources owned or controlled by the company	Fuel use in company vehicles, onsite boilers, industrial processes	High	Mandatory in most reporting regimes
Scope 2	Indirect emissions from purchased energy	Purchased electricity, heating, or cooling	Medium	Mandatory in most reporting regimes
Scope 3	All other indirect emissions across the value chain	Supplier emissions, transport, product use, waste disposal	Low	Optional but increasingly required by investors/regulators
Scope 4	Avoided emissions outside the company’s value chain enabled by its products/services	Teleconferencing software, energy-efficient appliances, green logistics	Variable	Voluntary, no formal accounting standard

Regulatory and Reporting Context

Governments worldwide are tightening disclosure requirements. For example, Australia mandates reporting of Scope 1 and 2 emissions under its National Greenhouse and Energy Reporting (NGER) scheme, with Scope 3 reporting voluntary but encouraged [1]. Globally, frameworks such as the Task Force on Climate-related Financial Disclosures (TCFD) and the International Sustainability Standards Board (ISSB) increasingly expect companies to disclose Scope 3 emissions [4].

The GHGP’s Scope 3 Standard, developed with input from over 2,300 stakeholders, remains the most widely accepted methodology for addressing value chain emissions [3]. However, Scope 4 remains outside regulatory mandates, with organisations like the Science Based Targets initiative (SBTi) cautioning that avoided emissions should not count toward net-zero targets [4].

Strategic Implications for Businesses

1. Prioritizing Scope 3 Reductions

Given its scale, Scope 3 is increasingly the focus of corporate decarbonization strategies. Companies across industries are engaging suppliers, redesigning logistics, and adopting circular economy approaches. For example, logistics companies are investing in green shipping and warehouse decarbonization, while consumer goods companies are switching to lower-emissions inputs such as recycled textiles [2].

2. Leveraging Scope 4 for Innovation and Differentiation

While voluntary, Scope 4 reporting can demonstrate innovation and market leadership. Companies that design products enabling downstream emission reductions can position themselves as sustainability leaders. For example, Schneider Electric’s Zero Carbon Project targets supply chain emissions while also promoting products that reduce customer energy use [5].

3. Avoiding Greenwashing Risks

Experts caution that Scope 4 should not overshadow Scopes 1–3. Overemphasis on avoided emissions, without robust reporting of direct and indirect emissions, risks accusations of greenwashing [4]. To build credibility, companies should report Scope 4 separately, clearly state assumptions, and avoid counting avoided emissions toward net-zero pledges.

4. Integrating Data and Collaboration

Accurate reporting requires collaboration across value chains. Supplier engagement, customer education, and partnerships for low-carbon innovation are essential to tackling Scope 3 and identifying Scope 4 opportunities. Tools from the GHGP, combined with advanced digital platforms, can streamline emissions data collection and enhance reporting reliability.

Future Outlook

As regulatory standards evolve, Scope 1 and 2 reporting are now baseline expectations, while Scope 3 is becoming central to investor and regulatory scrutiny. Scope 4, while voluntary, may gain greater traction as companies seek to showcase positive contributions beyond their direct footprint.

The challenge for businesses is to balance transparency and ambition: ensuring comprehensive Scope 1–3 disclosures while responsibly experimenting with Scope 4 reporting. In doing so, companies can not only comply with emerging rules but also seize opportunities for innovation, value creation, and competitive differentiation.

Final Thoughts

The categorisation of emissions into Scopes 1–4 provides businesses with a roadmap for understanding and managing their climate impact. While Scopes 1 and 2 are relatively straightforward, Scope 3 presents the largest challenge and opportunity, requiring deep collaboration across value chains. Scope 4, though voluntary, offers a lens to highlight how products and services contribute to avoided emissions.

Ultimately, companies that master transparent, comprehensive reporting across all scopes will be better positioned to meet stakeholder expectations, comply with regulations, and capture the benefits of the transition to a low-carbon economy.

References

[1] https://www.workforclimate.org/post/whats-the-difference-scope-1-2-and-3-corporate-emissions
[2] https://www.mckinsey.com/featured-insights/mckinsey-explainers/what-are-scope-1-2-and-3-emissions
[3] https://ghgprotocol.org/corporate-value-chain-scope-3-standard
[4] https://professional.ft.com/en-gb/blog/measuring-scope-4-emissions-what-boards-need-to-know/
[5] https://www.weforum.org/stories/2022/09/scope-4-emissions-climate-greenhouse-business/