Programmatic advertising generates 215,000 metric tonnes of CO₂ each month, across the US, UK, France, Germany and Australia, according to Scope3, a company that aims to measure emissions across the advertising supply chain. But by eliminating spend across certain high-emission websites, buyers can collectively cut up to 16 percent of those emissions.
The inaugural State of Sustainable Advertising report tracked carbon emissions for Q1 2023, and identified ‘Climate Risk’ websites whose emissions are twice the industry average. The research found that shifting ad spend away from high-carbon inventory can improve campaign performance, while removing some 33,500 metric tonnes of CO₂.
“The good news is that unlike many physical supply chains, the digital ad supply chain can be streamlined much more easily,” says Scope3 COO and co-founder Anne Coghlan. “By changing the way we configure the trillions of auctions that match advertisers with ad placements, we can dramatically reduce the energy consumption of the process.”
Omitting emissions
The study shows a vast range of emissions at the publisher level, anywhere between 187 and 1772 gCO₂PM (grams of carbon dioxide and equivalent greenhouse gasses per 1000 impressions). Scope3 divides these domains into carbon-efficient (Green) publishers, and at the other end of the emissions spectrum, unnecessarily high (Climate Risk) publishers. These tend to be low-value or made for advertising (MFA) content that wastes carbon and ad spend, effectively doing nothing for advertisers.
The data reveals that the worst 10 percent of domains contribute 33,500 metric tonnes of CO₂ – the equivalent of driving around the world 3,449 times, or 360 times to the moon. “This type of inventory needs to be defunded,” says the report. “It will also funnel more spend towards high quality journalism and help to reset the dynamics of online advertising to favour responsible and trusted media.”
At the same time, the research showed that factoring carbon emissions into buying decisions can also boost campaign results. For one advertiser, Scope3 performed post-campaign analysis to see the effects of pausing spend on the 10 percent most carbon-intensive domains. The results saw a 9.9 percent reduction in gCO₂PM, a 2.5 percent boost in click-through rate (CTR), and a 1.4 percent bump in video completion rate (VCR).
Life cycle
The report also breaks down the different parts of an ad journey by share of emissions: ad selection (60.7 percent), creative distribution (8.9 percent), media distribution (10.1 percent) and consumer devices (20.3 percent). The study notes that each area is controlled by a different stakeholder, and by identifying who is responsible for every aspect, each partner can see where action needs to be taken.
“Decisions need to be made with emissions in mind to achieve the goal of decarbonisation,” says the study. “Just as metrics like viewability, ad fraud, and attention have been folded in with performance metrics, carbon must also be taken into consideration.”
To achieve this, Scope3 recommends ad tech companies incorporate the gCO₂PM metric into their dashboards, and curate low-carbon media packages for easy activation. “All media owners and sellers should measure and understand their own footprint and assess opportunities to reduce emissions, and media buyers should incentivise this change with their spend,” concludes the report.
