Scope 3 · 25 March 2026
Scope 3 Emissions: The Complete Guide for Supply Chain Managers
Scope 3 emissions typically account for 70-90% of a company's carbon emissions, yet they remain the least understood and most challenging to measure. This guide explains everything you need to know.
What Are Scope 3 Emissions?
The GHG Protocol Corporate Standard divides greenhouse gas emissions into three scopes. Scope 1 covers direct emissions from sources owned or controlled by the company. Scope 2 covers indirect emissions from purchased energy. Scope 3 covers all other indirect emissions that occur in a company's value chain — both upstream and downstream.
The 15 Scope 3 Categories
The GHG Protocol defines 15 categories of Scope 3 emissions, spanning upstream activities (purchased goods and services, capital goods, fuel and energy-related activities, upstream transportation, waste, business travel, employee commuting, upstream leased assets) and downstream activities (downstream transportation, processing of sold products, use of sold products, end-of-life treatment, downstream leased assets, franchises, and investments).
Why Scope 3 Matters
For most organisations, Scope 3 emissions represent the vast majority of their total carbon emissions — often 70–90% or more. This means that a net zero strategy that focuses only on Scopes 1 and 2 will fail to address the most significant sources of emissions. Increasingly, regulators, investors, and customers are requiring full Scope 3 disclosure.
The 2027 NHS Requirement
From April 2027, all NHS suppliers must report all relevant Scope 3 emissions as part of their Carbon Reduction Plan. This is a significant step change from current requirements and will require many organisations to undertake a comprehensive Scope 3 assessment for the first time.
