The difficult part of Scope 3 is organising change across businesses you do not control. An emissions inventory makes the challenge visible. Supplier relationships, purchasing decisions and finance help determine what happens next.
I have spent much of my career working on that connection, first at CDP and now with colleagues at EcoVadis. This guide is about the decisions buyers can make: what to ask of suppliers, what support to offer and how to judge progress. It draws on our published work and the standards linked below.
01 / Understand the task
What is Scope 3 decarbonisation?
Scope 3 covers indirect emissions elsewhere in a company’s value chain, beyond those accounted for in Scope 2. The GHG Protocol’s corporate value-chain standard organises them into 15 upstream and downstream categories. These extend beyond suppliers to activities such as product use and investments. GHG Protocol: Corporate Value Chain Standard
Supply-chain decarbonisation addresses the activities behind the emissions associated with purchasing and supplier relationships. Its relevance varies by business. Start by understanding where the material emissions arise, then identify the decisions that can change the underlying activity.
Measuring the footprint.
Changing the activity.
An improvement in calculation can make an inventory more accurate. An operational or purchasing change can alter emissions. A credible programme needs to understand and communicate both.
If the next step is another data request, ask what the answer will help you decide. A supplier should be able to see the purpose of the exercise.
The Scope 3 execution perspectiveStandards checked · 15 September 2026
Set targets with SBTi
Account with the GHG Protocol
SBTi Corporate Net-Zero Standard V2.0 was published on 11 June 2026. It puts more emphasis on implementation, transition planning and transparent reporting of progress and barriers. Procurement teams should prepare for it now. Validation opens in Q1 2027; SBTi still directs 2026 submissions to V1.3.1. Both versions can be used from Q1 2027 through 31 January 2028, after which V2.0 is required for new submissions. The standard and transition guidance
The GHG Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard remains the published reference for the inventory. It covers 15 categories; it does not prescribe a company’s SBTi target. The two frameworks have different jobs. The published Scope 3 standard
Accounting rules are also being revised. GHGP’s July 2026 announcement describes a consolidated standard with ISO, including Scope 3 and Actions and Market Instruments. The AMI work proposes separate statements for physical emissions, market instruments and the wider impact of actions. It is still in development: its whitepaper is not a final standard. GHGP’s development update AMI: current status
For a buyer, the immediate task is straightforward: agree which target framework and accounting rules apply, keep the evidence behind any claim, and record what changes in the supplier’s business. New frameworks should make that work clearer, not put it on hold.
02 / Choose the priorities
Start where influence can become action
Use the inventory to locate significant sources, then bring procurement’s understanding of the supply base into the discussion. A large estimated footprint, a critical supplier relationship and an imminent product decision may point to different priorities. Make the reason for each choice visible.
- Materiality: which activities appear consequential, and how confident is that assessment?
- Influence: what can the buyer change through specifications, supplier relationships, contracts or collaboration?
- Readiness: what does the supplier need to take a useful next step?
- Timing: which sourcing or investment decisions create an opportunity to act?
Make the next ask fit the supplier.
In my conversation with Kimberly-Clark’s Anne-Laure Green, she described grouping suppliers by their carbon-management maturity and giving each group a clear next step. The approach puts sustainability into the scorecards and sourcing processes procurement already uses.
Read EcoVadis’s Scope 3 roadmapSome suppliers will need help to start measuring. Others will be ready to discuss an investment or a product change. The point is to make the next conversation useful for both sides.
03 / Make engagement useful
Give the supplier a reason and a route to act
At Sustainability LIVE, I put it this way: Ask the question because asking the question drives the change that you want to see.
September 2026 panel coverage
A request should explain what is needed, why it matters to the relationship and what support follows. Ask the supplier what is preventing progress. The answer may be capacity, finance, unclear expectations or a competing demand from another customer.
For target-setting, use the SBTi version that applies to your submission and plan for the V2.0 transition described above. For the engagement itself, agree who is responsible, what the supplier needs and when you will review progress. Collecting commitments is only one part of the job.
Track four stages: a supplier responds, makes a commitment, takes action and provides evidence of what changed. Look at progress between those stages as well as the number of suppliers taking part.
Buyers have work to do too. If a supplier needs a decision on specifications, a clearer demand signal or access to finance, put that on the agenda. Write down what each side will do before the next review.
Explore supplier engagement strategy04 / Connect action with finance
Make the commercial signal tangible
When finance is a constraint, ask what kind of support would unlock the intended action. Better working-capital terms, an investment decision and a long-term purchasing commitment address different problems. Define the constraint before choosing the mechanism.
Walmart · HSBC · CDP
Walmart’s December 2021 announcement linked eligible suppliers’ financing prices to CDP scores, targets and reported impact. The mechanism offered early payment of approved invoices through HSBC. I contributed commentary in my CDP leadership role.
Read Walmart’s programme announcementVodafone · Citi · CDP
Vodafone and CDP developed an environmental framework using 12 criteria from CDP’s survey. The programme offered the prospect of preferential supplier-financing rates, initially through Citi.
Read Vodafone’s programme announcementThese programmes show how a buyer and a bank can reward environmental performance. Their announcements establish the design, rather than the emissions saved as a result. Ask whether the financing addresses the supplier’s actual obstacle, then look for evidence of the action it supports.
Make sure suppliers understand the criteria and can participate.
My finance and institutional record05 / Read the evidence
Know what a carbon number can support
Before using supplier information, establish the reporting period, boundaries, method and supporting evidence. Ask whether the information is suitable for the decision at hand and which limitations need to remain visible.
Quentin Fornezzo and I set out EcoVadis’s approach in Beyond Disclosure: Building Trust in Supplier GHG Data. The methodology checks supporting documents, accounting practice and the plausibility of the reported figure. It also distinguishes data checked through EcoVadis’s process from data independently verified by an auditor. Our technical whitepaper EcoVadis Carbon Data Reliability Levels
In a business review, keep three records alongside each other: what was reported, what action was implemented and why the inventory changed. They answer different questions. A new estimate, a fall in purchasing volume and a reduction in an activity’s emissions should each be explained.
A reliability rating helps you judge a piece of data. It does not, by itself, establish an emissions reduction or show that an SBTi target has been met. Keep those conclusions tied to the relevant evidence and rules.
Explore Scope 3 data quality and reliability06 / Build in resilience
Lower emissions, stronger supply chains
The supply base faces environmental pressures while it works to reduce its own impacts. Ask about the capacity to respond to disruption as well as the emissions-reduction plan. Water dependencies, sourcing locations and forest-related commodity exposure can change the questions a buyer needs to ask.
This has been part of the discussion for years. Our 2015–2016 CDP–BSR report From Agreement to Action examined supplier emissions and resilience together, including water risk and procurement’s role. The need to help suppliers adapt has only made the relationship more important. The original CDP–BSR report
Take the discussion back to a specific relationship. What is the critical dependency? What response is feasible? Who would fund or support it? Which purchasing decision might strengthen the supplier’s ability to adapt?
A credible plan can pursue lower emissions and greater resilience together while keeping the objectives and evidence for each clear.
Explore resilience, water and forestsThe decision worksheet
Take one priority into the next business review
Choose one supplier relationship or category. Use these six prompts to prepare a focused discussion with procurement, sustainability and finance. This is a discussion aid, not an assessment score.
| Decision | Bring to the discussion | Leave with |
|---|---|---|
| Where to focus | The material activity, relationship and uncertainty | One priority with a clear reason |
| What to change | A supplier action or purchasing choice | The next decision and its owner |
| What is preventing it | The supplier’s account of the obstacle | Support needed from each party |
| How to make it viable | The commercial or financing constraint | An incentive or investment question to resolve |
| How to judge progress | Current data, limits and action evidence | A way to explain what changed |
| How to strengthen resilience | A relevant dependency or disruption risk | A response, an owner and a review date |
What will be different
by the next review?
Write down the action, the owner, the evidence expected and the date. Include the buyer’s commitments alongside the supplier’s.
Common leadership questions
Keep the conversation clear
Do we need perfect data before engaging suppliers?
Begin with the information that is fit for the decision, and make its limitations explicit. An exploratory supplier discussion and a quantified accounting claim require different levels of evidence. Improve the information where a gap prevents a consequential choice.
Who should own a Scope 3 supplier programme?
Assign clear responsibilities across functions. Sustainability can guide the climate objective and evidence; procurement brings the commercial relationship; finance can help assess incentives and investment. A named executive sponsor should resolve priorities and ensure that decisions have owners.
Does a supplier target demonstrate an emissions reduction?
A target establishes an intended outcome. Ask separately about the actions implemented, the results observed and how changes are reflected in the reported inventory.
Where does sustainable finance fit?
Use it where a financial constraint or incentive affects the intended action. Start with that business problem, then assess the mechanism and the evidence needed. The two programme examples above show different ways to connect supplier information with financing terms.