Programmatic Advertising: Why Have Pollution and Carbon Impact Disappeared from the Conversation? 🌱

By Max Legrand · GreyFox Ads · A perspective from France

Between 2020 and 2024, carbon impact seemed to be THE big sustainability topic in programmatic advertising. 🌱 Today, AI and CTV dominate the conversation. But did the unnecessary pollution disappear — or did we just stop talking about it?

1. Carbon impact was everywhere. Where did the conversation go?

From 2020 to 2024, carbon impact was one of the most visible themes in programmatic advertising. Climate disasters — from wildfires in Australia and California to major floods across Asia and Europe — dominated news coverage. Environmental concerns were front and centre. 🌪️

Today? The headlines in our little AdTech world are more likely to be about artificial intelligence and Connected TV. Under economic pressure, advertisers understandably focus on return on investment. But this change in priorities doesn't make inefficient advertising supply chains any less inefficient.

2. From climate ambitions to economic pressure

In Europe, the Corporate Sustainability Due Diligence Directive (CSDDD, also called CS3D) formed part of a wider effort to strengthen corporate responsibility. Meanwhile, Donald Trump's re-election in 2024 brought a very different political message from the United States: “Drill, baby, drill!” 🛢️

Our reading is that this political shift added pressure on European policymakers to reconsider the pace and burden of environmental rules, particularly in relation to industrial competitiveness (although individual EU policy decisions have several causes, and the directive's precise legal requirements and timetable have evolved).

As we highlighted in the original commentary, Le Monde also reported on environmental policy rollbacks across Europe. The broader atmosphere matters because programmatic advertising does not operate in an economic or political vacuum.

3. Unnecessary pollution: where effectiveness and sustainability meet

Here is the point that too often gets lost: carbon impact and genuine advertising effectiveness are connected. In programmatic, some activities consume infrastructure and generate data traffic without necessarily creating additional value for the advertiser.

Think of repeated auction requests, redundant intermediaries, pages crammed with advertising placements, and impressions with very little realistic chance of attracting attention. These are not all identical environmental problems, but they are sensible places to look for avoidable waste.

Reducing waste is not the same as proving a quantified reduction in CO₂ emissions (that requires an appropriate measurement boundary and methodology). It is, however, a practical starting point.

4. Why ads.txt alone cannot solve the problem

One shortcut we don't find convincing is relying on publishers' ads.txt files as a proxy for environmental performance. ads.txt is designed to identify authorised digital sellers; it does not directly measure energy use, bid duplication, advertising effectiveness or carbon emissions.

We have discussed the biases of this approach in our earlier analysis. If the goal is to reduce unnecessary pollution, we believe it is more useful to examine the actual supply paths and advertising environments.

5. First filter: SPO towards publishers' own SSP seats

Supply-path optimisation (SPO) can favour the SSP seats operated by publishers themselves, reducing unnecessary intermediaries and limiting the effects of bid repeating — multiple requests for essentially the same advertising opportunity.

Why send a DSP several near-identical opportunities when a cleaner path could do the job? Fewer redundant requests can mean less processing and a clearer buying chain (provided that deduplication and supply-path choices are assessed using real auction data).

We've explored this issue in our analysis of bid repeating and in the vicious cycle of bid repeating.

6. Second filter: stop funding ad-cluttered websites

Another source of waste is the proliferation of sites and subdomains that maximise the number of ad placements per page. More banners do not automatically mean more attention — or more brand impact.

Filtering out excessively cluttered environments can help advertisers focus on cleaner, more useful placements while discouraging inventory inflation. See our earlier post about ad clutter and our analysis of MFA websites.

7. Third filter: question low-impact small creatives

What about small ad formats such as 320×50 or 728×90? They may require fewer resources per creative than larger formats, but that alone doesn't establish their advertising value.

Our position at GreyFox Ads is deliberately provocative: if a placement is unlikely to have a meaningful effect on the brand, why keep buying it simply because its individual technical footprint looks modest?

That does not mean every small format is ineffective. Impact depends on placement, creative execution, audience and campaign objectives. The important question is the impact achieved relative to the resources used, not the creative dimensions in isolation.

8. A practical approach: remove waste before chasing labels

That's the logic behind how we approach inventory quality at GreyFox Ads: remove avoidable waste, favour more direct supply paths and concentrate investment where advertising has a better chance of working. 🌱

We believe the quality French Open Web can be both a more effective and a more responsible place to advertise — without pretending that one simple filter can solve the entire carbon question.

For more on our approach, discover GreyFox Ads Master Deals, designed to simplify programmatic activation for Media Traders.

Original LinkedIn post: Read the original commentary. The observations and recommendations in this article reflect GreyFox Ads' editorial perspective.