Sustainable leadership: how to get procurement to act on Scope 3

You have a Scope 3 number. The category manager renewing a supplier contract next week does not have it, and would not know what to do with it if they did. Getting colleagues to act on emissions data is the part of a sustainability programme that no reporting framework explains.

The short version

• Shared numbers move people. A buyer acts on a supplier emissions figure sitting next to the price on the contract they are about to renew.
• Put the data where the work already happens. Procurement will use emissions data in the system they log into every morning, and ignore the same data in a second portal.
• Attach a decision to every request. Name the suppliers, name the deadline, and say what you want done with them.
• Track the share of spend with supplier-specific (primary) data. It tells you whether engagement is working, which an internal survey about how people feel does not.

Why do sustainability programmes stall after the first baseline?

Because the number stops moving once it leaves the sustainability team. The baseline sits in a spreadsheet, built largely from spend multiplied by industry average factors, secondary data, and nobody in procurement can see which supplier it points at. The same spend multiplied by the supplier's own factor is primary data and does. Buyers describe the same position in their own words: heads in spreadsheets, working from proxy data, chasing suppliers for figures that arrive late and in the wrong format. Proxy figures are secondary data; a supplier's own figures, once they arrive, are primary.

Proxy data is the specific blocker. A category average tells a buyer that chemicals are worse than software, which they already knew. It cannot tell them that this supplier is worse than that one at the same price, and that is the only comparison a sourcing decision can act on.

What does a category manager need before they will act?

Supplier-level emissions, next to spend, in the system they already use. That is the whole list. DitchCarbon provides verified emissions data for over 2 million organisations, built on primary emissions data wherever it exists, so procurement, sustainability and finance teams can measure and act on supply chain and portfolio emissions from one source.

Three things make a number usable by somebody who did not build it:

• It resolves to the right legal entity. Entity resolution against DUNS, LEI and ISIN identifiers, so the figure attaches to the supplier on the contract rather than a similarly named parent.
• It carries its own provenance. Every figure carries its source and change history, so a buyer challenged in a supplier meeting can say where it came from.
• It arrives in time to matter. Numbers you can defend within 2 weeks, rather than after the renewal has been signed.

Coverage gaps are shown rather than hidden, which matters more than it sounds. A buyer who finds one silent gap stops trusting the whole dataset.

How do you ask suppliers for data without making it a burden?

Start with what you already know about them and ask them to confirm it. A request that arrives prepopulated with a supplier's own published figures, primary data under the GHG Protocol, gets a higher response rate than a blank survey, because the supplier is checking work rather than starting it. An investment team asking portfolio companies for the same information runs the same play.

Scale follows from that. A recent deployment reached about 60% of a large supplier base within 2 weeks, because most of that base never had to answer anything: the data already existed and only needed matching and checking.

Anyone reading this from the other side of the request can shorten it further. Claiming a company profile is free, and it means answering once and reusing the answer with every customer who asks. Claim your profile.

How do you tell whether engagement is working?

Count decisions and coverage. Employee sentiment is a real thing to measure, and it is not evidence that a Scope 3 programme is progressing. Three measures are enough to run an engagement programme on, and all three come out of the same dataset the buyers are working in.

• Share of spend with supplier-specific data. How much of the footprint rests on a named organisation's own figures rather than an industry average.
• Coverage of the suppliers that matter. The proportion of top spend and highest emitting categories with a usable figure, which is a harder test than the number of suppliers contacted.
• Sourcing decisions with an emissions input. How many renewals, tenders and category reviews in the last quarter had a supplier emissions figure in front of the decision maker.

What makes the number defensible when somebody pushes back?

Independent verification of how it was calculated, and a trail an auditor can follow. The DitchCarbon Portal calculator is verified to ISO 14064-3, limited assurance, by UL Solutions, renewed annually. The emission factor methodology for spend-based Scope 3 categories 1 and 2 was independently assessed by Globus Thenken in August 2025. The industry average applied to spend is secondary data; the organisation's own factor applied to the same spend is primary. Both reports are downloadable from the trust centre.

That pairing is what audit-ready means here: auditable by a third-party auditor against a named standard, with provenance behind every figure. DitchCarbon is the only specialist Scope 3 tool with third-party assurance of its calculation methodology, and the table of every vendor we checked, verified or not, is published in Who's really verified? A reality check on carbon software assurance.

Where to start this quarter

Pick one category, put supplier-level emissions next to spend for every supplier in it, and take it to the category manager before the next renewal round. One category with real numbers changes more behaviour than a year of internal communications. See how supplier engagement works with verified data.