Scope 3 emissions

The GHG Protocol splits Scope 3 into 15 categories spanning upstream activities (purchased goods, inbound freight, business travel) and downstream ones (distribution, product use, end of life). For most hardware companies two categories dwarf the rest: purchased goods and services, and use of sold products when the product consumes energy. Every casting, PCB, and fastener arrives carrying embedded emissions from supplier processes.

That is why ownership lands on procurement. The emissions sit inside supplier factories, so reducing them means changing what you buy (material substitutions, recycled content), whom you buy from (supplier energy mix), and how goods move (ocean versus air). Data collection is the hard part: supplier surveys get weak response rates, boundaries differ from one reply to the next, and product-level carbon footprints remain rare. Practical programs rank categories by spend and mass, write emissions expectations into the supplier code of conduct, and weight them in awards as part of sustainable procurement.

Estimation follows the same data-quality ladder as the rest of carbon accounting, and AI is starting to ease the collection burden, a topic covered in how AI supports sustainability in supply chains. LightSource, an AI-native procurement platform for direct materials, structures the line-item spend and supplier data that Scope 3 estimates are built on.

Frequently asked questions

What are Scope 3 emissions?

Scope 3 emissions are the greenhouse gas emissions that occur across a company's value chain rather than from its own operations (Scope 1) or purchased energy (Scope 2). The GHG Protocol defines 15 Scope 3 categories spanning upstream activities like purchased goods and inbound freight and downstream ones like distribution, product use, and end of life.

Why does procurement own Scope 3 emissions?

For manufacturers, category 1, purchased goods and services, is usually the largest Scope 3 category by far, and those emissions sit inside supplier processes. Reducing them means changing what you buy (material substitutions, recycled content), whom you buy from (supplier energy mix), and how goods move (ocean versus air), all of which are sourcing decisions.

Why is Scope 3 data collection so hard?

Supplier surveys get weak response rates, boundaries differ from one reply to the next, and product-level carbon footprints remain rare. In one example, a buyer surveyed 300 suppliers, 90 responded, and only 12 provided product-level numbers, so the team estimated the rest with activity-based factors and focused primary-data requests on the 25 suppliers covering half of spend.

How do companies reduce Scope 3 emissions in practice?

Practical programs rank categories by spend and mass, write emissions expectations into the supplier code of conduct, and weight emissions in sourcing awards. One robotics manufacturer found machined aluminum contributed 19,000 tonnes of its 80,000 tonne CO2e inventory and cut roughly 8,000 tonnes by shifting two part families to high-recycled-content billet.

How large is Scope 3 compared with Scopes 1 and 2?

For most hardware companies, two Scope 3 categories dwarf the rest: purchased goods and services, and use of sold products when the product consumes energy. In one example inventory of 80,000 tonnes CO2e, the company's own operations and purchased energy accounted for 5,000 tonnes while purchased goods alone accounted for 58,000, so a single supply-side change outweighed Scopes 1 and 2 combined.