A sustainability lead inside a media agency, brand or publisher in 2026 reports against a stack one layer higher than measurement. Climate disclosure standards, science-based target frameworks and assurance methodologies each define what the measured data must serve, who validates it, and which investor and regulatory pipelines it flows into.
Scope 1, 2 and 3 in advertising context. A brand's own offices and ad-production facilities sit in Scope 1 (direct emissions) and Scope 2 (purchased electricity). The carbon footprint of the digital advertising the brand pays to deliver — from ad-tech bidding all the way down to the user's device rendering the impression — sits in Scope 3. For most consumer brands, Scope 3 dominates the inventory, and the ad-supply chain is one of the larger uncategorised lines inside it.
The compliance map isn't one framework — it's a stack of four sitting above measurement.
The four below define what a CSRD-reporting media company must report on, target by, validate against, and disclose to. Your specific reporting obligations vary by company size, jurisdiction and listing status — but every media-spending organisation now touches at least two of them.
What does ESRS E1 require under CSRD?
CSRD is the directive. ESRS E1 is the standard.
The European Sustainability Reporting Standards were adopted by the European Commission in July 2023 under the Corporate Sustainability Reporting Directive. ESRS E1 is the climate-specific topical standard, one of twelve published by EFRAG — covering transition planning, greenhouse-gas emissions across Scope 1, 2 and 3, energy consumption, climate-related risks and opportunities, and the financial effects of climate on the business.
Wave 1 covers approximately 12,000 large EU public-interest entities reporting for fiscal years beginning on or after 1 January 2024. Wave 2 in 2025 brings other large companies into scope. The disclosure scope per company is determined by a double materiality assessment — emissions are reportable wherever they are financially material to the company or where the company's activities are materially impactful on climate.
For digital advertising specifically, three GHG Protocol Scope 3 categories pull in ad-related emissions depending on how the company accounts for them. Category 1 (purchased goods and services) captures media spend at the agency-buying level. Category 9 (downstream transportation and distribution) captures the data-and-network leg of ad delivery in some classifications. Category 11 (use of sold products) captures the downstream ad emissions of branded campaigns that drive consumer activity. Different sustainability teams classify ad emissions differently across these three — the inconsistency is itself one of the open questions ESRS E1 disclosures are surfacing.
IFRS S2 — the global sustainability baseline in effect since 2024
The International Sustainability Standards Board sits inside the IFRS Foundation — the same body that maintains accounting standards used in 140-plus jurisdictions. IFRS S2 (Climate-related Disclosures) is the ISSB's climate-specific standard, published in June 2023 and effective for annual reporting periods beginning on or after 1 January 2024.
IFRS S2 builds on the recommendations of the Task Force on Climate-related Financial Disclosures (TCFD) and consolidates them into a single global baseline. Scope 1, Scope 2 and Scope 3 emissions disclosure is required, with limited first-year transition relief on Scope 3.
The standard has been endorsed or is progressing endorsement in more than 20 jurisdictions — including the United Kingdom, Canada, Australia, Singapore, Hong Kong, Japan, New Zealand and Brazil — with phased mandatory adoption across 2026 and 2027. For multinational media groups operating across those markets, IFRS S2 becomes the lowest-common-denominator disclosure framework alongside region-specific standards like ESRS E1. The IFRS Foundation publishes the standard and adoption progress at ifrs.org.
How do SBTi targets cascade into the ad supply chain?
The Science Based Targets initiative is the framework brand-side advertisers use to commit to Paris-aligned emissions targets. It was founded in 2015 by CDP, the UN Global Compact, the World Resources Institute and WWF. More than 6,000 companies globally have committed to science-based targets as of 2025.
The Corporate Net-Zero Standard is the SBTi's flagship framework for setting near-term and long-term targets aligned with 1.5°C pathways. The standard requires Scope 3 emissions inclusion whenever Scope 3 accounts for 40% or more of a company's total inventory — a threshold most consumer brands and most media-spending companies clear comfortably.
For a brand advertiser with a validated SBTi target, the supply chain has to follow. Media spend flows into Scope 3 Categories 1, 9 or 11 — which puts pressure on the agencies, ad-tech vendors and publishers in the chain to provide audit-ready per-campaign carbon data. Audit-ready in this context means three things: a documented measurement methodology, traceable per-campaign inputs, and a transparent statement of what is in scope and what is not. Measurement methodologies that pursue alignment with the underlying GMSF, GHG Protocol and IAB Tech Lab anchors land in this supplier-disclosure conversation as the practical output the buyer side asks for.
The verification gap — why "audited" doesn't yet exist for ad carbon
Disclosure standards require numbers. Validation frameworks define who checks them.
ISO 14064-3:2019 is the international specification with guidance for the validation and verification of greenhouse-gas statements. ISAE 3000 (Revised) is the International Standard on Assurance Engagements published by the IAASB, covering assurance engagements other than audits of historical financial information. Big-four assurance firms operate under both when providing limited or reasonable assurance over corporate sustainability reports.
Both standards apply at the corporate-reporting level. What does not yet exist in 2026 is a specialised assurance methodology, recognised by the major audit chains, for per-impression or per-campaign ad-carbon data. The closest analogue is the financial-audit playbook adapted for sustainability — assurance providers sign off on the aggregate Scope 3 number a company reports under CSRD or IFRS S2, but the underlying per-impression measurement methodology is treated as an input assumption rather than independently verified.
That gap will close. ISO Technical Committee 207 on environmental management, IAB Tech Lab's Sustainability Working Group, and the assurance practices of the big-four firms are all working in adjacent territory. Until then, "pursuing alignment" remains the honest framing — and per-impression measurement methodologies that document their inputs and assumptions transparently provide the strongest defensible position inside a CSRD or IFRS S2 disclosure today.
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