Advertising Emissions Are Becoming A Media Planning Metric

Ad Net Zero Australia and climate consultancy 2XE released a white paper on August 26 that puts a number on a cost many marketing teams have barely measured. The analysis estimates advertising accounts for more than 5% of an organisation's upstream Scope 3 emissions on average, rising to about 16% in government, infrastructure and public services.

The timing matters. Australia's mandatory climate reporting regime is expanding, and AASB S2 requires covered entities to disclose Scope 1, Scope 2 and Scope 3 emissions. Marketing is moving from the language of brand purpose into the mechanics of financial reporting.

The common response would be to treat this as another compliance obligation. That misses the operating decision in the report: carbon can become a media-planning variable alongside cost, reach and performance, but only when CMOs obtain activity-level data from agencies, platforms and production partners.

What The Australian Analysis Measured

Advertising emissions are fragmented across media, production, technology and suppliers. The paper cites WPP's 2019 value-chain baseline, where media buying contributed 54% of advertising ecosystem emissions, creative production 14% and enterprise technology 6%.

2XE found advertising represented about 9% of upstream Scope 3 emissions for media, entertainment and digital businesses. Its chief executive Nick Palousis said an emissions source averaging above 5% “deserves a plan.” The implication for CMOs is direct: marketing is too material to leave entirely with sustainability or finance teams.

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Why Spend-Based Accounting Creates A Budget Trap

Most organisations begin by multiplying advertising expenditure by an industry emissions factor. That gives finance a baseline, but it makes cost a proxy for carbon. Under that model, cutting the marketing budget becomes the clearest route to reporting lower emissions, even when a better-quality media buy produces less carbon per impression.

Activity-based measurement changes the unit of analysis. It connects emissions to suppliers, formats, placements and delivery conditions, allowing a CMO to compare carbon intensity with effectiveness before a campaign runs.

Australian Ethical shows why that distinction matters. Working with Benedictus Media and oOh!media, the brand cut out-of-home emissions per dollar by 63% and per thousand impacts by up to 82% through targeting, renewable-powered inventory, recyclable materials and more energy-efficient creative. Overall paid-media emissions fell 21%, while brand-awareness uplift was 50% stronger than its previous campaign.

Campaign Performance Changes The Sustainability Case

The report also profiles broadcaster SBS, which reduced advertising's share of its carbon footprint from 6% in FY22 to 3% in FY25. A premium-drama BVOD campaign used Hearts & Science's Renewables Ad Engine to schedule delivery when more renewable electricity was available, cutting campaign carbon intensity by 24.6% without reducing reach.

Adjacent market evidence points in the same direction. A Scope3 meta-analysis covering more than 500 million impressions found lower-carbon campaigns delivered 29% fewer emissions, 2.6% lower cost per acquisition and 52% higher click-through rates. Those figures do not prove every low-carbon plan will outperform, but they make waste reduction a commercial question, not just an environmental claim.

What CMOs Should Change Now

The immediate decision is not to add a carbon target to a campaign brief and wait. CMOs should establish how marketing emissions are currently calculated, identify the highest-spend or highest-impact channels, and require agencies and key vendors to disclose activity-level inputs using a consistent method such as Ad Net Zero's Global Media Sustainability Framework.

Procurement and performance reviews also need to reflect the change. Supplier contracts can specify emissions data, reporting boundaries and improvement targets, while campaign scorecards can place carbon intensity beside reach, cost and business outcomes.

This may shift leverage toward media owners, agencies and technology vendors that can provide auditable delivery data. Suppliers relying on broad estimates may find themselves harder to defend as climate disclosures mature across APAC. For CMOs, the larger lesson is practical: measure advertising emissions closely enough to optimise them, or risk having someone else reduce them by cutting the budget.