Ad carbon measurement had an undisputed reference point for years: when an agency needed emissions per impression, the default answer was Scope3. Its data flowed into industry studies, its benchmarks shaped pitches, and “add the Scope3 number” became a line item in agency reporting.
In 2026, the company’s own front door tells a different story. The homepage headline reads “Interchange. Agentic advertising at enterprise-grade scale” — agent-to-agent media buying on the open AdCP protocol. The blog’s recent posts are about brand agents and AI-native buying. The only published pricing is for media transactions. Carbon hasn’t disappeared — it continues on a separate sustainability platform — but it is no longer the story the company tells about itself.
If your CSRD workflow depends on a measurement vendor, what happens when that vendor’s roadmap is about buying media, not measuring it?
That is the question sending media agencies to search for a Scope3 alternative — and it deserves a factual answer, not a pile-on. This article covers what actually changed, what an alternative needs to do for an agency, and how the 2026 options compare.
What actually changed at Scope3
The facts, from the company’s own public pages:
- March 2025 — Scope3 repositions as an agentic media platform; it later co-develops the Ad Context Protocol (AdCP) and becomes a founding member of the agentic-advertising ecosystem around it.
- 2026 — Interchange launches as the flagship: agent-to-agent media buying with published transaction pricing (4% routed / 8% decisioned — media-transaction fees, not measurement pricing).
- Today — sustainability survives as one solution line on a sub-platform, alongside brand agents and media products. None of the recent blog posts lead with carbon.
Two things are true at once. Scope3’s emissions dataset still operates and remains widely used — agencies running it are not suddenly without data. And the company’s center of gravity has visibly moved to a different business. For a buyer, that second fact matters: roadmap, support attention, and pricing focus follow the lead product.
Why media agencies specifically are looking
Agencies sit in the most exposed seat. Three pressures stack.
Client reporting is contractual now: sustainability clauses in agency contracts increasingly require per-campaign emissions reporting, and the agency owns the deliverable even when the data comes from a vendor.
CSRD makes advertising a value-chain line item: advertisers in scope of EU sustainability reporting treat purchased media as part of their value-chain (Scope 3) footprint — and ask their agencies for numbers that can survive an auditor’s questions. “A vendor gave us a number” is a weaker answer every year.
And methodology scrutiny is rising: the industry’s reference methodology is Ad Net Zero’s Global Media Sustainability Framework (GMSF), and buyers have learned to ask whether a vendor’s number aligns with it, what data feeds it, and whether the calculation is reproducible.
None of these pressures require leaving Scope3. All of them require knowing what the alternatives are.
What a Scope3 alternative needs to do for an agency
Four requirements separate a serious option from a dashboard:
- GMSF alignment — the methodology belongs to Ad Net Zero, not to any vendor, so the tool should compute within that framework to stay comparable across vendors and defensible in client reporting.
- Per-impression granularity — campaign-level averages can’t drive optimization; the unit that matters is the impression, by format, channel, and market.
- A defensible data source — modeled from bid-stream logs, contributed by publishers, or measured where the ad rendered; each is legitimate, but they answer an auditor differently.
- Reporting output, not just a score — CSRD-shaped exports, per-market breakdowns, and a methodology document you can hand to a client’s sustainability team.
The 2026 alternatives, compared
| Vendor | Approach | GMSF alignment | Distinct angle | Pricing |
|---|---|---|---|---|
| Scope3 | Modeled, server-side per impression | Data widely used within GMSF workflows | Largest incumbent dataset; company focus now Interchange/agentic | Contact/login |
| Cedara | Measurement platform; contributed publisher data preferred over estimation | Built on GMSF; runs benchmark studies | The measurement standard-bearer | Contact sales |
| Good-Loop | GMSF-integrated emissions model | Yes | Pairs emissions with attention/wastage framing | Contact sales |
| Carbon Intelligence | Activity-based (positions against spend-based) | States GMSF alignment | EU-hosted, AI-assisted; accuracy figures are vendor claims | Contact sales |
| IMPACT+ | Media-impact and emissions measurement | GMSF-aligned | Campaign-level carbon plus broader media-impact scoring | Contact sales |
Three honest notes. First, every row above is drawn from public positioning; capabilities move quickly, and a shortlist deserves a live demo round. Second, accuracy percentages a vendor publishes about itself — anyone’s — are claims, not audited facts. Third, “alternative” doesn’t have to mean replacement: several agencies run an incumbent dataset and a measurement layer side by side and let the divergence inform the audit conversation.
Modeled or measured: the question that decides it
Most ad-carbon numbers in circulation are modeled: emissions estimated from bid-stream and server-side signals, applied per impression. Done well — and Scope3’s dataset is the most widely adopted example — modeling scales across the entire programmatic supply chain.
The alternative philosophy is measurement: deriving the number from what verifiably happened — a publisher contributing real infrastructure data, or an impression observed on a real device in a real country at a real time. The GMSF itself ranks contributed and measured data above estimation in its data hierarchy.
Why it matters to an agency: the energy an ad consumes is dominated by the delivery chain rather than the creative file alone — Adform’s Programmatic Carbon Index attributes roughly 76% of programmatic emissions to the ad-selection process, a figure Cedara’s benchmark work independently lands near. A modeled number applies assumptions about that chain; a measured one observes its endpoint, including the electricity grid actually powering the impression at that hour. The same campaign can carry a very different footprint in a coal-heavy market than in a hydro-heavy one — which is why per-country, time-resolved grid intensity sits at the core of how we calculate.
For client reporting, the practical translation: a modeled number answers “what does media like yours typically emit?” A measured number answers “what did your media emit?” Auditors notice the difference.
What this means if you are on Scope3 today
No urgency theater: the sustainability platform operates, and switching costs are real. A measured approach for an agency in 2026:
- Keep the incumbent data flowing — continuity matters for trend reporting.
- Ask the roadmap question directly — what carbon-measurement capabilities shipped in the last two quarters, and what is committed for the next two?
- Pilot one alternative on one campaign — compare per-impression outputs, per-market splits, and the export your client’s sustainability team actually has to file.
- Anchor on the framework, not the vendor — if both tools compute within GMSF, divergence between them is a data-source conversation, not a methodology war.