Earth from space

Tackling media decarbonization one campaign at a time

Co-authored by Laura Wade and Susanna Pitts

This article is part of a series of articles from the WARC Guide to net zero marketing. Read more.


The term “media decarbonization” has emerged over the last three years in parallel to the advertising and media industries' realization that net-zero business practices are imperative for our own and our clients' long term prosperity. Media decarbonization means a significant reduction in the carbon intensity of media agencies’ output – that is, the media plans and placements. WPP’s GroupM has committed that every media plan will be net zero by 2030, thus accelerating the focus on the techniques and innovation to achieve this.

While important steps are being taken, the ability for the industry to measure and mitigate the impact of media is fairly limited. Success requires us to find decarbonization solutions that can be scaled within day-to-day practices to ensure we achieve the absolute reduction necessary. 

At Essence, we recognize media decarbonization is only one lever against our net zero ambitions. This article is a review of our actions and learnings from applying the Institute of Practitioners in Advertising’s carbon calculator as we begin the task of decarbonizing our media campaigns.

Knowing where carbon is in your media plan

Media planning is coming to the forefront as companies look to minimize their carbon impact across their supply chain. Understanding one’s current emissions provides the foundational data for both tackling the hotspots and measuring progress. Through our work with the IPA on its calculator, and GroupM and Essence’s own work, we are developing a much greater idea of what this looks like. But there is still work to do.

Carbon calculators themselves are fairly simple to use. Once one keys in the media plan details, the calculator applies an algorithm to compute the carbon footprint of a live campaign. Using annually updated electricity emissions factors, it takes into account an average of emissions across suppliers in each channel. Variables considered could include desktop-versus-mobile consumption, file sizes, view time, screen type, power consumption and run cycles.

It is in the use of the output that things get technical. Depending on the way a calculator is built, the output is an estimate of the carbon generated by a media plan based on such variables as the channels and formats to be used (measured in metric tonnes of Carbon Dioxide Equivalent (tCO2e)).

To put the carbon data to work, strategists and planners need to have a base knowledge of climate science and terminology. This enables them to understand the impacts of various planning scenarios and have informed conversations with their clients. Without these conversations to drive change, the calculator output is just an offset number.

Carbon offsetting is a temporary stopgap, as it is an investment in removing carbon from the atmosphere rather than reducing its production in the first place, which is why our primary focus should be on reducing the amount of carbon created before we offset.

The current version of the industry's IPA carbon calculator doesn’t include data at the supplier level – a gap that will need to be filled to gain much more precise carbon data. This exclusion limits our ability to engage with vendors based on their sustainability policies and actions. Without it, we are limited in how we make decisions to reduce carbon emissions during ad delivery.

For now, carbon reduction during planning primarily focuses on two areas: more sustainable creative assets and enforcing best-practice media behaviors.

Digital: A challenge and an opportunity

While every channel has a carbon footprint, the rapid growth of digital and a hyper-connected world has created unprecedented energy demands, meaning that digital poses a significant challenge as an industry “carbon hotspot.”

Until carbon calculators have fully inclusive and accurate vendor data, efficient campaign management and elimination of digital waste is the foundation for a low-carbon campaign, so the best practices that we’ve adhered to for years still stand true:

1. Address impression wastage

Capped Frequency, a standard practice for media campaigns that limits how often an ad appears, not only offers a better audience experience but reduces waste. Ensuring a capped frequency across the entire campaign drives efficiency for audiences, campaigns and energy consumption.

Within the digital and social ecosystem, audience expectations are for shorter formats in line with the platform experience. Combined with the fact a 15-second format is half the carbon weight of a 30-second (all variables being the same)1, reducing video length and weight offers a way to reduce.

And finally, once you’ve achieved your KPIs, turn off your campaign.

2. Reduce high-carbon formats

It may feel like an obvious statement, but anything that slows down the web experience has a heavy download weight, which equals a higher carbon footprint. With this in mind, avoid intrusive pop-ups automatically loading and creating carbon.

Consider the effects of “high impact” takeover formats with video embedded: does the increased visibility and performance of a takeover outweigh the inevitable increase of associated carbon emissions? Or could lighter versions of static images or gifs match performance and deliver reduction. According to SeenThis’ recent whitepaper(2), streaming as an alternative to the traditional download model for digital assets can reduce a campaign’s carbon footprint from between 10%-40%.

From a carbon reduction perspective, we need to also consider the impact of autoplay or unskippable formats and identify ways to reduce unnecessary data loads in the plan.

3. Reduce data waste

Data is energy. The more data we consume, the more emissions we produce. The International Data Corporation (IDC) predicts 175 zettabytes of new data will be created annually by 2025, up from 33 zettabytes in 2018(3).

When it comes to digital advertising, data waste can be defined in two ways:

  • Excess data: Data that is transferred over the internet but is never viewed or applied for its intended purpose

  • Vanity data: Data transferred for “improved quality” but is not detectable by the human eye

Excess data is part of the industry make up. Most display and video advertising is traded on a CPM basis, and we accept a certain degree of non-viewable impressions will be bought in the process of delivering viewable impressions. However, when viewed through a sustainability lens, the tension between cost efficiencies and carbon efficiency is evident, as each non-viewable impression creates excess data waste.

With vanity data, this is about reviewing creative requirements. For example, is the highest resolution available really necessary when considering that 56% of internet traffic was viewed on mobile screens in 2021(4)? 

4. Supply chain optimization

Consider how digital advertising is bought, especially the sprawling programmatic landscape with auctions on top of auctions (now the norm due to header bidding), which creates additional unnecessary waste.

Essence works with a smaller number of supply-side platforms and authorized supply paths to ensure transparency and quality. By doing so, we reduce the volume of bids we ask our demand-side platforms to listen to and the number of auctions we participate in. This approach reduces our supply-chain energy consumption.

Buying through ad networks, additional intermediaries and third-party tags also adds carbon weight to your campaign, so consider the upside of these for quicker delivery but then turn them off once they have hit their targets. Where possible, avoid the excessive use of third-party tags and remove ad networks and intermediaries to shorten supply paths consistently.


Sources 1. IPA Carbon Calculator, 2021; 2. Benon, J (2021), “The Time to Act is Now: Media Industry’s Unique Position on Reducing the Internet’s Carbon Dioxide Impact,” Dec. 2021; 3. WPP, “Digital Sustainability 2021,” Oct. 2021; 4. StatCounter, Desktop vs. Mobile vs. Tablet Market share, Q1-Q4 2021