The average online ad campaign emits 5.4 tons of CO2 a year. That’s more than an average UK adult’s annual carbon footprint. But change is coming: spearheaded by Ad Net Zero, the digital advertising industry is committed to decarbonising and making a positive contribution to the global effort to curb climate change.
Such initiatives are powerful, but nothing moves the needle quite like market pressure. Requests for proposal now often include questions about the service provider’s carbon footprint and the overall footprint of an advertising campaign. Pressure has been particularly strong from luxury and FMCG brands, which live or die by how they are perceived by increasingly environmentally conscious consumers.
This pressure feeds all the way down the supply chain to publishers, with ad tech intermediaries offering or developing low-carbon auction packages so that brands can align their advertising with their net-zero objectives. Ad Net Zero’s target for a carbon neutral advertising industry by 2030 might seem far away, but at the current pace of progression, being carbon neutral may be necessary to survive in the market before then.
The path to net zero is not easy. It’s made more difficult today by the lack of clear standards as to how emissions are calculated, who is responsible for them, and which offsetting schemes are appropriate — or at all effective. IAB Europe’s Sustainability Standards Committee is working towards addressing this gap, but in the meantime specialist organisations such as Scope3 and IMPACT+ offer carbon audits and certification for digital advertising companies.
Despite the challenges, there are steps every company operating in the industry can take today to make progress towards sustainable digital advertising.
What we can do now to reduce carbon emissions in digital advertising
We may not see them pumping out exhaust fumes, but the algorithms behind the technology that keeps digital advertising running are power-hungry and can quickly rack up a significant carbon debt. To avoid this, any data centres — whether owned internally or leased externally — should be run on renewable electricity, which is becoming increasingly available as the world’s energy mix transitions away from fossil fuels.
Google Cloud, for example, offers carbon-free hosting by default by offsetting emissions with wind and solar purchases. Google also shares pre-offset emissions for each data centre so customers can allocate usage to regions where the carbon load is lightest. If a company operates in a region with high fossil fuel use in its electricity generation, it can run slow, high intensity tasks — such as modelling — in a low carbon region, while keeping low latency tasks in local data centres to preserve performance.
Decisions made early in campaign planning can also help to reduce final emissions. Peak periods come with a higher carbon load; could timings be adjusted to prioritise evenings and weekends? Video assets require more energy to deliver; can the same results be achieved with lighter weight animated image formats? Wi-fi produces less emissions than mobile internet; is it worth favouring broadband-connected devices?
The answer to each question depends on the campaign’s KPIs, capabilities, and objectives, but carbon emissions should be considered a cost like any other, and one that we are less able to afford by the day.
Such decisions in campaign planning are an opportunity to weigh up whether impressions are worth sacrificing for reduced emissions. There is not necessarily a right answer — and offsetting can compensate, if due diligence is followed — but knowing there are ways every campaign can make progress towards net-zero is an important first step.
Which brings us to education. Every company in digital advertising has an opportunity to educate partners, employees, and investors on reducing their carbon footprint, especially if the company in question is committed to a net-zero supply chain. Few in this industry can claim to be truly carbon-free at this point, so being understanding of emissions rather than chastising them is the fair approach, but expect patience to wear thin as we near Ad Net Zero’s 2030 milestone.
Digital advertising has a waste problem, and it’s delaying progress
Before we can hit the 2030 milestone, we need to address waste. The ANA and ISBA’s respective audits of the programmatic supply chain both revealed widespread inefficiency, with the former calculating $20 billion in wasted spend in the US alone. But there is more than a financial cost to waste: every dollar spent on a failed bid also adds to a campaign’s carbon price tag.
Optimising the supply path by reducing intermediaries to the essentials and being more selective with media owners (the ANA study found the average campaign runs on 44,000 websites) can shave down wasted spend, deliver a more effective campaign, and cut down on emissions. Supply path optimisation is a triple win, and one that must be a priority across the industry.
This drive for efficiency aligns with the wider objectives the digital advertising industry is pursuing in the wake of third-party cookies’ much-delayed demise. Now that troves of unconsented data cannot be plundered for targeting, we are moving towards an ecosystem based on non-invasive, AI-powered contextual and attention-based optimisation — which come with the bonus of significant carbon savings.
Attention optimisation is good for users, advertisers, publishers, and the planet
The premise is simple: the more attention an ad gets, the lower the waste. By optimising the delivery of ads to match the context of the surrounding page, media, or signals generated by the user, it is more likely that the user will engage with the ad. This is all achieved without any need for direct user identification, enabling an effortless and continuously optimised targeting approach that is regularly refreshed with AI.
AI is key to the success of such solutions, while also delivering carbon savings of its own. It would take hundreds, if not thousands of hours for legacy data processing technologies to achieve what an AI engine can do in moments. Sustainability is all about doing more with less, a concept that AI technology will take to the extreme.
Optimising for attention also applies this ‘more with less’ approach to ad placements. Instead of cluttering a page or filling a video with as many slots as possible, a handful of high-attention ads can be delivered instead, reducing waste and dramatically improving the user experience. For example, a single ad inserted as the user is scrolling through an article, optimised for the moment they are most likely to be engaged, is more elegant and effective than an easily ignored banner ad flashing at the top of the screen in perpetuity.
Research by Lumen and Scope3 found that attention plummets the more ads are on screen at a time, resulting in an almost sixfold increase in the emissions per attentive second. Attention needs a measurement standard to achieve its full potential in digital advertising, but it’s clear any company committed to reducing campaign emissions should start optimising for attention now.
High-attention placements and formats are better for users, advertisers, publishers, and — most importantly — the planet and all who call it home.