Ad Net Zero & the Global Media Sustainability Framework
The advertising industry spent years unable to answer a basic question: what is the carbon cost of a thousand ad impressions? Every vendor measured it differently, so no two numbers could be compared. Ad Net Zero and the Global Media Sustainability Framework exist to fix that — to give media the common measurement language that GHG accounting already gave fuel and electricity.
This is not one standard but two intertwined things: a five-point industry action programme, and the voluntary measurement framework that makes its media target enforceable.
Ad Net Zero is a voluntary advertising-industry decarbonisation programme built on a five-point action plan. Its Global Media Sustainability Framework standardises how media emissions are measured across six channels as Scope 3.
Two things, often confused — the programme and the framework
The single most common mistake in this area is treating “Ad Net Zero” and “the Global Media Sustainability Framework” as synonyms. They are related but distinct, and the distinction governs how each is used. Ad Net Zero is a decarbonisation programme with a five-point action plan covering the whole advertising lifecycle. The GMSF is a measurement framework that answers one of those five points — how to quantify the emissions of media planning and buying — in technical detail.
- A voluntary industry decarbonisation initiative
- Founded by the UK Advertising Association with the IPA and ISBA; launched November 2020
- Built on a five-point Action Plan spanning operations, production, media, events/awards and behaviour change
- Supporters commit to measure and reduce emissions, typically “by 2030”
- Global from Cannes Lions 2022; chapters across the US, Europe, Australia, New Zealand and beyond
- A voluntary, technical measurement framework for media emissions
- Delivers Action 3 of the Ad Net Zero plan (media planning and buying)
- Standardises GHG measurement across six media channels
- Provides formulae, data-request mechanisms and default values
- Latest published version: GMSF v1.3 (2025), aligned with the GHG Protocol and ISO 14067
Ad Net Zero tells the industry what to decarbonise and by when; the GMSF tells media buyers how to measure one of those areas consistently. A supporter can sign up to the Ad Net Zero programme without yet using the GMSF, but cannot credibly deliver the programme’s media action (Action 3) without a consistent measurement method like the GMSF underneath it.
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Governance and the GARM transition of August 2024
The GMSF’s governance changed materially in 2024, and any current reference must reflect it. The framework was launched at Cannes Lions on 17 June 2024 as a joint project between the Ad Net Zero community and the World Federation of Advertisers’ Global Alliance for Responsible Media (GARM). Less than two months later, on 8 August 2024, the WFA announced that GARM would discontinue its activities, after an antitrust lawsuit filed by X (formerly Twitter) over an alleged advertising boycott drained the small non-profit’s resources. GARM’s original remit was brand safety and harmful-content avoidance, not sustainability — the GMSF was a late and separate workstream.
GARM’s shutdown removed one of the two original co-stewards of the GMSF, but it did not withdraw the framework. Ad Net Zero became the ongoing home for the GMSF, with continued input from IAB Europe’s methodology working group, measurement vendors and the original cross-industry contributors. The substantive consequence is custodial, not technical: the framework continued to develop, reaching v1.3 in 2025. Any document that still describes the GMSF as a “GARM framework” or implies GARM governs it is out of date — GARM ceased operations on 8 August 2024.
Why media emissions matter — and how big they are
Media is a distinctive emissions problem because it is large, distributed, and almost entirely Scope 3 — sitting outside an advertiser’s direct operational control in the value chain of agencies, ad-tech intermediaries, publishers and platforms. The footprint is driven by data centres, networks and the billions of end-user devices that render ads, which is why it overlaps with digital-carbon measurement generally rather than with a factory’s combustion emissions.
The wide 5–40% range is the practical point. For a consumer-goods advertiser with large physical operations, media may be a rounding error; for a digital-native brand whose product is delivered online, media and digital infrastructure can dominate the corporate footprint. That variance is exactly why a consistent measurement framework matters: without one, an advertiser cannot even tell whether media is a material category worth managing.
Before the GMSF, published estimates for the carbon of a thousand digital ad impressions varied by an order of magnitude depending on the measurement boundary, the formula, and the source data. The same campaign could be reported as low- or high-carbon depending only on which vendor measured it. The GMSF’s core purpose is not to produce the “true” number — it is to make different vendors’ numbers comparable by fixing the boundaries, formulae and default values they must share.
The five-point Ad Net Zero Action Plan
The Action Plan structures the whole programme. Each action targets a different source of advertising emissions, and each carries a “by 2030” supporter ambition. Media is Action 3 — the action the GMSF operationalises.
The advertising business’s own operational footprint — electricity, business travel, waste. By 2030, supporters measure their emissions, set a science-based target and reduction plan, and act on operational reduction opportunities. This is ordinary corporate carbon accounting under the GHG Protocol.
The making of ads — shoots, travel, equipment, post-production and data storage. Supported by production-specific tools such as AdGreen. By 2030, supporters measure production emissions and act on reduction opportunities through the production process.
The emissions of placing and delivering ads across channels. This is the action the GMSF delivers: by 2030, supporters measure the emissions attributed to media purchases, act on reduction opportunities, and embed sustainability into media buying decisions.
Industry awards and marketing events. By 2030, supporters act on reduction opportunities across event production and delivery, and awards bodies embed environmental criteria into judging — Cannes Lions, for instance, added a sustainability question to its entry process.
The distinctive action: using advertising’s influence to accelerate sustainable consumer choices, while avoiding greenwashing. By 2030, advertisers have clear reference points for responsible environmental claims and for marketing that supports a sustainable transition.
It is worth being precise: the GMSF measures media (Action 3) only. Operational emissions (Action 1) are measured with a standard organisational inventory under the GHG Protocol Corporate Standard, and production emissions (Action 2) use production-specific tools. Treating the GMSF as the measurement method for the whole Action Plan is a category error.
Where Ad Net Zero sits in the carbon stack
Like other sector initiatives, Ad Net Zero and the GMSF do not replace the underlying carbon-accounting science — they apply it to a specific domain. The GMSF is a media-specific application layer over the same GHG Protocol Scope 3 accounting and the same digital-carbon estimation methods used elsewhere.
The GMSF — structure and recommendations
The GMSF is organised around a set of recommendations that move an organisation from inconsistent estimates toward comparable, auditable data. The framework is deliberately described as voluntary and pre-competitive — it sets a common language without dictating which suppliers a buyer must use or how aggressively to reduce.
| Recommendation | What it establishes |
|---|---|
| Metrics & methodology | A voluntary, consistent framework to measure GHG emissions across the six media channels, improving the accuracy and comparability of carbon accounting. |
| Data request | An efficient, standardised mechanism to collect first-party emissions data from media partners and the value chain, reducing duplicate and inconsistent requests. |
| Channel Emissions Frameworks (CEFs) | Channel-by-channel formulae and boundaries, so each media type is measured according to its own physical reality rather than one generic formula. |
| Default values | Published fallback values for use where primary data is unavailable, so a measurement can still be produced — and so two organisations using defaults produce comparable figures. |
The framework is explicitly a “living” document. Channel-specific elements evolve as data availability improves and as the marketplace learns which measurement steps are material. This is why a version number matters: a GMSF v1.1 figure and a GMSF v1.3 figure for the same campaign can differ because the underlying formulae and defaults were refined between versions. Any reported media-carbon number should state the GMSF version it was produced under.
The six media channels
The GMSF covers six channels, each with its own emissions framework because the physical sources of emissions differ fundamentally between, say, a streamed video impression and a printed page.
Servers, ad-tech intermediaries, content delivery networks, and the end-user device that renders the ad. The most data-rich and fastest-evolving channel, and the one most refined in v1.2/v1.3.
Broadcast and connected-TV (CTV) delivery, set-top boxes and screens. Spans traditional linear broadcast and streamed delivery, which have different infrastructure footprints.
Billboards and posters, including digital out-of-home (DOOH) screens. Emissions come from manufacturing, energy use of digital displays, and physical production and installation.
Paper, ink, printing and distribution. A materials-and-logistics footprint closer to a product life-cycle assessment than to a digital one.
Radio and digital audio / streaming. Combines broadcast infrastructure with streaming-delivery emissions for on-demand audio.
Screening energy, distribution of content to venues, and venue operations apportioned to advertising.
The channels are not equally developed. Digital is the most mature, with detailed formulae, data levels and default values. The Audio, Print and Cinema formulae were substantially built out in the v1.3 update of 2025. When comparing media-carbon figures, comparability is strongest within a channel and weakest across channels, because the boundaries and data maturity differ.
The digital methodology in detail
The digital channel is where the GMSF is most prescriptive, because digital advertising’s emissions are computational and traceable to specific infrastructure. The methodology decomposes a digital impression into stages, each with its own energy and emissions, and is in effect a life-cycle assessment of an ad impression.
The programmatic auction and targeting decisioning that selects which ad to serve. Emissions scale with the number of active paths and servers involved — direct and programmatic-guaranteed paths are relatively fixed, while open-auction programmatic can involve many authorised sellers, multiplying the computational effort per impression.
Serving the creative asset across content delivery networks. Emissions scale with the data “payload” — the weight of the ad’s assets — plus server overhead. A heavy video creative carries far more delivery emissions than a lightweight static image.
The energy the end user’s device consumes to receive and render the ad. Depends on device type, format and viewing duration, and on the grid intensity where the device is located.
Published GMSF-aligned worked examples illustrate the order of magnitude: per-impression delivery on the order of fractions of a gram to a few grams of CO₂e, with one industry explainer citing roughly 0.05 kg CO₂e for an ad-selection-and-delivery example and a payload on the order of 0.3 MB per impression. Reported figures of between roughly 50 and over 1,500 grams of CO₂e per thousand impressions have appeared in industry analyses, the spread reflecting creative weight, supply-path complexity and grid intensity. These are illustrative published ranges, version- and context-dependent — not fixed factors. Always reproduce the GMSF version and inputs behind any quoted figure rather than treating a single number as canonical.
Where primary data is unavailable — common for “walled garden” platforms that disclose little — the methodology permits documented default assumptions, such as an estimated server count or a default geographic grid mix. The discipline the GMSF imposes is not that every input be measured, but that every assumption be declared, so that two estimates built on defaults remain comparable. This mirrors the data-quality logic of ISO 14067 product carbon footprinting and the digital estimation approach behind a website digital-carbon calculator.
Mapping media emissions to GHG Protocol scopes
For an advertiser, almost all media emissions are Scope 3 — they occur in the value chain of agencies, ad-tech vendors, publishers and the end users who view the ads. The GMSF is therefore a Scope 3 measurement framework, and its outputs feed an advertiser’s Scope 3 inventory rather than its Scope 1 or 2. The same emissions sit in different scopes depending on whose books they land in, which is the usual Scope 3 mirror effect.
| Activity | Advertiser’s scope | Where it is Scope 1/2 for someone else |
|---|---|---|
| Ad-tech servers / data centres running the auction | Scope 3 (purchased services) | Scope 2 electricity for the ad-tech vendor / platform |
| Content delivery and network transmission | Scope 3 | Scope 2 for the CDN / telecom operator |
| End-user device energy to render the ad | Scope 3 (use of sold/served content) | Outside any single organisation’s Scope 1/2 — household/consumer energy |
| OOH digital screen energy | Scope 3 | Scope 2 for the OOH media owner |
| Print paper, ink and distribution | Scope 3 (purchased goods & services) | Scope 1/2/3 split across the printer and logistics provider |
| The advertiser’s own marketing-team operations | Scope 1 / 2 | — |
Because media emissions are Scope 3, they fold into the same value-chain inventory that frameworks like CSRD / ESRS E1 require advertisers to disclose. For a media-heavy advertiser, a GMSF-based media measurement can be a material input to the Scope 3 figure in a regulated sustainability statement — which is why measurement-vendor outputs increasingly reference both the GMSF and the GHG Protocol together.
The measurement maturity model
The GMSF frames adoption as a progression rather than a binary. An organisation does not need perfect data on day one; it is expected to start with benchmarking and improve the granularity and auditability of its data over time.
Establish a baseline using available data and published default values. The goal is a defensible starting figure and an understanding of where media sits in the wider footprint — not precision.
Use the baseline to identify high-impact media activities and act on them — lighter creative, cleaner supply paths, lower-carbon channels and formats. Measurement becomes a decision input, not just a report.
Replace default values with primary supplier data, tighten the data request, and improve auditability so the figures can withstand assurance and feed regulated disclosure.
Reduction levers in media
Measurement is the means; reduction is the end. The GMSF deliberately stops short of dictating reductions — it is pre-competitive and avoids telling buyers where to spend — but the practical levers the framework’s structure exposes are consistent across the industry.
| Lever | Mechanism | Primary channel |
|---|---|---|
| Lighter creative | Reduce the data payload per impression — compress assets, cap video weight, prefer efficient formats | Digital, TV/video |
| Supply-path optimisation | Shorten the programmatic supply chain; cut redundant auction paths and low-quality reseller hops | Digital |
| Cleaner infrastructure | Favour partners running on lower-carbon grids and efficient data centres | Digital, OOH |
| Channel and format mix | Shift spend toward lower-carbon channels/formats where campaign effectiveness allows | All |
| Supplier selection | Filter media partners on environmental performance and data transparency — described by Ad Net Zero as the largest single decarbonisation lever in the media value chain | All |
| Waste reduction | Cut invalid traffic, over-delivery and impressions on inattentive or fraudulent inventory | Digital |
The most direct way to cut media emissions is to buy fewer impressions — and that collides with the commercial purpose of advertising. Ad Net Zero and the GMSF largely sidestep this by focusing on the carbon intensity per impression and on eliminating waste, rather than on reducing absolute volume. Industry commentators have noted that the harder question — whether and how impression volume itself should fall — sits mostly outside the framework’s pre-competitive boundaries.
Action 5, claims, and greenwashing risk
Action 5 — harnessing advertising’s influence for behaviour change — is the part of Ad Net Zero with the sharpest reputational edge, because advertising that promotes sustainable choices sits one short step from advertising that overstates them. Ad Net Zero’s own guidance treats responsible environmental claims as a core reference point, and cautions specifically against treating carbon offsetting or credits as a shortcut to net-zero claims.
Ad Net Zero’s materials are explicit that real-world absolute emission reductions in line with the Paris Agreement are the priority, and that caution is needed where companies lean on offsetting or credits as a route to net zero, given the inconsistencies in credit quality. For an advertiser, this means a “carbon neutral campaign” claim built primarily on offsets carries both methodological and regulatory risk — the same gross-versus-net discipline that the GHG Protocol and regulated disclosure regimes enforce applies to advertising claims about advertising itself.
The convergence of advertising-standards regulators tightening enforcement of environmental claims and disclosure regimes demanding evidenced Scope 3 figures means Action 5 is increasingly a compliance question, not only an ethics one. Measurement under the GMSF is what gives an environmental claim about media a defensible evidentiary base; an unmeasured “sustainable media” claim is exactly the kind of statement now most exposed to challenge.
How Ad Net Zero relates to SBTi, CSRD and the GHG Protocol
Ad Net Zero and the GMSF are frequently set against general carbon standards as if they competed. They do not — they apply the general standards to advertising. The table clarifies the relationship.
| Dimension | Ad Net Zero / GMSF | GHG Protocol | SBTi | CSRD / ESRS E1 |
|---|---|---|---|---|
| Type | Sector initiative + measurement framework | Accounting standard | Target-setting standard | Disclosure regulation |
| Scope of focus | Advertising & media emissions | All emissions, all sectors | Organisation-wide targets | Organisation-wide disclosure |
| Supplies factors? | Channel formulae + default values (version-dependent) | Method only | No | No |
| Legal status | Voluntary | Voluntary | Voluntary | Mandatory (EU) |
| Built on | GHG Protocol Scope 3 + ISO 14067 | — | GHG Protocol | GHG Protocol |
| Relationship | Feeds the Scope 3 media line | The accounting base | Sets the reduction ambition | Consumes the inventory |
A media-conscious advertiser runs them together: the GHG Protocol Scope 3 Standard structures the value-chain inventory, the GMSF supplies the media line within Scope 3, SBTi sets the reduction ambition the Ad Net Zero “by 2030” commitments echo, and CSRD / ESRS E1 consumes the resulting figures in a regulated disclosure. Ad Net Zero is the programme that ties the advertising-specific pieces of that chain together.
Supporter readiness checklist
This checklist separates programme-level commitments (joining and acting on the Action Plan) from the technical media-measurement work the GMSF requires. The programme track is usually quicker to satisfy; the measurement track is where the real effort sits.
Common errors
Frequently asked questions
Ad Net Zero is a voluntary, cross-industry decarbonisation programme for advertising. It was founded by the UK Advertising Association with the IPA and ISBA and launched its five-point Action Plan in November 2020, going global from Cannes Lions 2022 with chapters across the US, Europe, Australia and New Zealand. The plan targets emissions from advertising operations, production, media, events and awards, and uses advertising’s influence to support behaviour change. Supporters commit to measure and reduce their emissions, typically with “by 2030” ambitions.
The GMSF is a voluntary measurement framework that standardises how greenhouse-gas emissions from media are calculated across six channels — digital, TV, out-of-home, print, audio and cinema. It delivers Action 3 of the Ad Net Zero plan (media planning and buying), providing channel-specific formulae, a standardised data request, and published default values, all aligned with the GHG Protocol and ISO 14067. The latest published version is GMSF v1.3 (2025).
Ad Net Zero is the overall programme — a five-point action plan covering the whole advertising lifecycle. The GMSF is the technical measurement framework that operationalises just one of those points, media (Action 3). Ad Net Zero defines what to decarbonise and by when; the GMSF defines how to measure media consistently. A supporter can join the programme without yet using the GMSF, but cannot credibly deliver its media action without a measurement method like the GMSF underneath it.
The GMSF launched at Cannes Lions on 17 June 2024 as a joint project of Ad Net Zero and the World Federation of Advertisers’ Global Alliance for Responsible Media (GARM). On 8 August 2024 the WFA discontinued GARM, after an antitrust lawsuit from X (formerly Twitter) drained the small non-profit’s resources. GARM no longer governs the framework. Ad Net Zero became the sole ongoing steward, and the GMSF continued to develop, reaching v1.3 in 2025. Any reference describing the GMSF as a current “GARM framework” is out of date.
Six: digital, TV/video, out-of-home (including digital out-of-home), print, audio (radio and digital audio), and cinema. Each channel has its own emissions framework because the physical sources of emissions differ — a streamed video impression and a printed page are not measured the same way. Digital is the most developed channel, with detailed formulae and default values; the audio, print and cinema formulae were substantially expanded in the v1.3 update of 2025.
For an advertiser, media emissions are almost entirely Scope 3 — they occur in the value chain of agencies, ad-tech vendors, publishers and end-user devices, not in the advertiser’s own operations. The GMSF is therefore a Scope 3 measurement framework, and its outputs feed an advertiser’s Scope 3 inventory. The same emissions are Scope 2 (electricity) for the platforms and media owners whose servers and screens consume the energy — the usual Scope 3 mirror effect.
No. Both are voluntary. Ad Net Zero is an industry programme that organisations choose to support, and the GMSF is explicitly a voluntary, pre-competitive measurement framework. Neither carries statutory force. However, because media emissions are Scope 3, GMSF-based measurements increasingly feed inventories that mandatory disclosure regimes such as CSRD / ESRS E1 require — so the measurement can become indirectly necessary for compliance even though the framework itself is voluntary.
Ad Net Zero cites academic estimates putting the media industry at roughly 2–3% of total global greenhouse-gas emissions, and its 2024 reporting attributes a footprint of up to around 4% to digital advertising and its media ecosystem. For an individual advertiser, media can represent as little as 5% or as much as 40% of total organisational emissions, depending on the business. That wide range is precisely why consistent measurement matters — without it, an advertiser cannot tell whether media is a material category to manage.
The digital methodology decomposes an impression into stages — ad-space selection and programmatic decisioning, creative delivery across content delivery networks, and rendering on the user’s device — and estimates the energy and resulting emissions of each. Emissions scale with the complexity of the supply path, the data “payload” of the creative, and the grid intensity where servers and devices sit. Where primary data is unavailable, documented default values are permitted, with the discipline that every assumption is declared so estimates remain comparable. It is, in effect, a life-cycle assessment of an ad impression.
Ad Net Zero’s guidance prioritises real absolute emission reductions in line with the Paris Agreement and cautions against relying on carbon offsetting or credits as a route to net-zero claims, given inconsistencies in credit quality. A “carbon neutral campaign” claim built primarily on offsets therefore carries both methodological and advertising-standards risk. The defensible position is to measure media emissions under the GMSF, reduce them through the available levers, and reserve any neutrality language for what genuine reduction and high-quality removals support — with the measurement evidence to back the claim.
Measure the digital and Scope 3 emissions that feed a GMSF media footprint — using the same data-transfer, device-energy and grid-intensity logic the framework’s digital methodology relies on.