The ASA has published the findings of a new ‘pulse’ study exploring how environmental claims are used in online advertising. Using AI-assisted analysis, the study examined more than 7 million ads served to UK consumers. Its publication during London Climate Action Week comes at a time of increased public and industry focus on environmental claims and sustainability messaging. 

The study, part of our ongoing Climate Change and the Environment (CCE) work, analysed ads captured across Google search and website display advertising between September and November 2025. Using the ASA’s Active Ad Monitoring system, alongside expert human oversight, it examined how frequently environmental ad claims appear, where they are concentrated and the types of language advertisers use.

The report does not assess whether individual ads comply with the advertising rules. Instead, it provides a snapshot of how environmental claims are used across online advertising, helping identify patterns, emerging trends and areas where businesses may benefit from further support and guidance. 

The findings suggest that environmental claims remain relatively uncommon overall, appearing in around 1% of ads analysed. However, where they do appear, they are often framed in broad or absolute terms such as “eco-friendly”, “sustainable” or “carbon neutral”. Around three-quarters of the environmental claims identified in the study were classified as absolute claims.

Under the CAP Code, absolute environmental claims typically require a particularly high level of substantiation. The findings therefore suggest that potential regulatory risk is shaped less by how often green claims appear, and more by how they are framed.

The findings also highlighted examples of advertisers using more specific and qualified environmental messaging. In sectors such as transport and utilities, many advertisers were observed making comparative claims about emissions, efficiency or reduced environmental impact, rather than relying on broad or unqualified environmental claims. For example, claims about lower emission train travel compared with aviation alternatives on routes, or reduced energy consumption compared with specified alternative products.

The analysis identified environmental claims across a wide range of sectors, including food and agriculture, fashion retail, utilities, transport, homes and construction, and financial and professional services. It also highlighted emerging areas of activity, including claims by architecture firms promoting “sustainable” or “low carbon” homes. 

Alongside the report, CAP will shortly publish new guidance, Green-speaking with confidence, to help advertisers make clear, evidence-based environmental claims.  

By combining large-scale Active Ad Monitoring with Large Language Models and expert human review, the ASA was able to analyse advertising at a scale that would not be possible through complaint-based work alone. 

The findings will inform future ASA monitoring, engagement and guidance work, while continuing to support businesses in making environmental claims that are clear, accurate and appropriately substantiated. 

 

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