Quantifying the Carbon Footprint from Digital Ads: The Hidden Carbon Cost of Online Advertising

Attached (link to PDF) is the latest postgraduate research paper from our ongoing collaboration with leading academic institutions. We hope to encourage debate and increase understanding by continuing to invest in supporting science based findings and then disseminating this independent, academic-based knowledge regarding the advertising industry's environmental impact.

Net Zero Media set another digital advertising research question, and again the paper is free from any influence or commercial pressure. We remain committed to seeking academically sound information that provides genuine value to advertisers aiming to reduce the carbon intensity of their marketing activities.

The following summary and link to the full report are produced by Margaux Orchard for her major research project with the Capstone Environmental Masters programme at The University of Sydney.

While digital advertising continues to scale rapidly and deliver measurable business outcomes, it’s worth pausing to ask at what environmental cost? As Marguax’s report notes, “comprehensive carbon footprint assessment requires integration of complementary methodological approaches and standardised measurement frameworks.” To keep pace sustainably, the industry must move beyond assumptions of digital efficiency and invest in measurable, accountable systems that reflect the true impact of our online campaigns.

Summary of Findings

Ad spending in the global advertising market is forecasted to hit USD $1.16tn in 2025, with 81% of total ad spending coming from digital sources by 2030. However, the digital advertising industry is starting to face an inconvenient truth, that it is not as low-impact as it seems.

• Data centres (45% of ICT emissions) and network infrastructure (24%) are major contributors.

• AI-powered targeting, real-time bidding, and rich media formats like video increase energy intensity.

• AdTech companies driving the global dissemination of advertising, such as Google and Meta, are estimated to be driving  up to 4.9 million mt CO₂e in operational emissions per year.

• Operational factors like programmatic advertising, inefficient targeting, and ad format choices further influence the environmental impact.

This complex system powers the personalised, real-time ads we see daily—but it comes at an environmental cost that most advertisers aren’t tracking.

More Accessible but More Waste?

Online advertising’s accessibility has lowered the barrier to entry—anyone can launch a campaign at scale, instantly. But this ease of use may be accelerating overproduction, inefficiencies, and emissions. When ads are cheap and easy to produce, they’re also easier to waste.

While digital is often considered more efficient than traditional media, it comes with hidden costs. Algorithms require vast computing power, and most platforms don’t disclose ad-specific emissions, making it hard to manage the impact.

Measurement Gaps and the Path Forward

One of the biggest challenges in tackling digital advertising’s carbon footprint is the lack of consistent, transparent measurement. Emission estimates vary widely across the industry, and most platforms don’t disclose how much of their emissions are directly tied to ad services. Making it difficult for brands to understand, let alone manage, their emissions.

The field is further hampered by fragmented methodologies and major blind spots. Key components, like server-side energy use, ad content production, and emerging formats such as podcasts or AR/VR, are often left out of calculations. Much of the available data comes from industry reports rather than peer-reviewed research, and there’s limited integration of emissions metrics into existing ad-tech tools.

To move forward, the report calls for more granular, standardised research across advertising formats (social, video, display, search), better modelling of real-world conditions (such as regional energy mixes), and greater collaboration between academia and industry. Filling these gaps is essential if the sector wants to move from awareness to meaningful action.

About Net Zero Media

At Net Zero Media, we are driving a future where the advertising industry takes decisive action to reduce its carbon emissions.

Recognising the critical need for specialised technology to measure these Scope 3 emissions, Net Zero Media was founded by a collaboration of senior executives from the marketing, advertising, software and sustainability industries who developed CarboniQ to effectively measure the environmental impact of every advertising campaign across all media channels.

Our mission is to transform the advertising landscape by integrating media planning expertise with advanced technology and a deep understanding of climate science. We empower the industry to navigate complex challenges and deliver sustainable solutions, driving decarbonisation.