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Scope 3 Emissions: Why They're 70–90% of Your Carbon Footprint

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Scope 3 emissions refer to all indirect greenhouse gas (GHG) emissions that occur outside a company's own operational boundaries but are part of its value chain. They are defined by the Greenhouse Gas (GHG) Protocol as the third and broadest emissions category, covering both upstream and downstream activities — from raw material extraction and supplier processes to product use and disposal.

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Scope 1, 2, and 3 at a glance

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The GHG Protocol distinguishes between three emissions categories that together make up a company's Corporate Carbon Footprint (CCF) and a product's Product Carbon Footprint (PCF):

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• Scope 1 – Direct emissions from sources owned or controlled by the company, such as manufacturing facilities, vehicle fleets, or on-site fuel combustion.
• Scope 2 – Indirect emissions from purchased energy, including electricity, district heating, cooling, or steam used in production.
• Scope 3 – All other indirect emissions across the value chain, including suppliers, transportation, product use, and end-of-life treatment.

For most companies — especially in manufacturing, industrial goods, and consumer products — Scope 3 emissions represent the largest share of the total carbon footprint, often between 70 and 90 percent. Without reliable Scope 3 data, a company's carbon footprint remains incomplete.

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The 15 Scope 3 categories under the GHG Protocol

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The GHG Protocol divides Scope 3 into 15 categories, split between upstream and downstream activities:

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Upstream categories

• Purchased goods and services
• Capital goods
• Fuel- and energy-related activities (not included in Scope 1 or 2)
• Upstream transportation and distribution
• Waste generated in operations
• Business travel
• Employee commuting
• Upstream leased assets

Downstream categories

• Downstream transportation and distribution
• Processing of sold products
• Use of sold products
• End-of-life treatment of sold products
• Downstream leased assets
• Franchises
• Investments

Not every category is equally relevant for every business. For manufacturers, the majority of emissions typically falls under purchased goods and services and use of sold products — areas where reliable CO₂e data at material and process level is essential for accurate accounting. This is also why Scope 3 emissions are a central focus for procurement teams aiming to identify low-carbon materials and suppliers.

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Why are Scope 3 emissions important?

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Scope 3 emissions are becoming increasingly important for several reasons:

• Regulatory pressure: Reporting requirements such as the CSRD and other sustainability regulations increasingly demand full value chain coverage.
• Net Zero targets: Science-based climate targets (e.g. under the SBTi) are not credible without Scope 3 included.
• Supply chain transparency: Companies are increasingly required to share emissions data with customers and business partners, for example under CBAM or supplier data requests across the supply chain.
• Identifying emission hotspots: Granular Scope 3 data shows which materials, suppliers, or processes offer the greatest potential for reduction measures.

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How are Scope 3 emissions calculated?

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Calculating Scope 3 emissions typically relies on a combination of primary and secondary data:

• Primary data comes directly from suppliers, production sites, or logistics partners and provides the highest level of accuracy.
• Secondary data uses verified industry averages and emission factors to fill data gaps when primary data is unavailable.

For a robust Scope 3 calculation — particularly at the product level as part of a Product Carbon Footprint (PCF) calculation — a consistent, up-to-date CO₂e database validated against the GHG Protocol and ISO 14067 is essential. This allows materials, components, and processes across the supply chain to be assessed on a comparable basis, making it easier to pinpoint emission hotspots and prioritize reduction levers. To understand how Scope 3 calculations relate to a full Life Cycle Assessment (LCA), see our comparison of LCA vs. PCF.

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Want to calculate your Scope 3 emissions with verified CO₂e data?

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Explore our Carbon Database and PCF calculation tools, or contact our team to get access to the sustamizer® and streamline Scope 3 and PCF reporting across your value chain.