Note: This advice is given by the CAP Executive about non-broadcast advertising. It does not constitute legal advice. It does not bind CAP, CAP advisory panels or the Advertising Standards Authority.


In 2021 the ASA and CAP launched a Climate Change and the Environment (CCE) project, to respond to the ongoing climate crisis and take action to ensure that environmental claims in advertising are not misleading or irresponsible. Updates about our work in this area are published here.  

The project consists of several strands, including:

  • Sector-specific reviews, focusing on previous ASA work on these issues, common claims in ads for these sectors, and any recent legislation or developments in understanding of their environmental impacts
  • Research into consumer understanding of different types of environmental claims
  • Targeted investigations, to establish new precedent and take action against advertisers who use green claims in a way that is likely to mislead or cause harm
  • Updates to our existing resources, and creation of new educational material

Please see the updated CAP Advertising Guidance on The environment: misleading claims and social responsibility in advertising, and the new e-learning module that covers the rules on Climate Change and the Environment

While this advice represents the current position, the ASA’s CCE project is actively reviewing our approach to these issues, which may lead to further rulings and updates to this guidance.

Marketers wishing to promote the environmental credentials of their travel services should consider how the ASA is likely to interpret them and the sort of evidence required to substantiate environmental claims. Marketers should take government guidance into account, including the Competition and Markets Authority’s Green Claims Code, as well as making sure they adhere to Section 11 of the CAP Code, which covers environmental claims.

The Code requires the basis of environmental claims to be clear. Unqualified claims could mislead if they omit significant information (rule 11.1). The meaning of all terms used must be clear to consumers (rule 11.2).

Marketers proposing to make claims based on future projections, should ensure that they are clear, based on accurate data and, if relevant, suitably qualified.

Aspirational claims

Wording such as “environmentally friendly” or synonymous claims should not be used unless marketers can provide convincing evidence that their product will cause no environmental damage, taking into account the full life cycle of the product.

Marketers must ensure that claims which are based on only part of the advertised product’s life cycle, do not mislead consumers about the product’s total environmental impact (rule 11.4).

In 2023 the ASA ruled that a poster advertising an airline, which included the text “CONNECTING THE WORLD. PROTECTING ITS FUTURE. #MakeChangeFly” and an image of a plane showing the underside as an image of the earth from space, gave a misleading impression of the advertiser’s environmental impact.

The advertiser said that the ad was part of a campaign intended to address the need to reduce the environmental impact of flying, as well as to drawing attention to what they were doing to achieve this. The ad included a link to a website which featured more information about the steps they were taking to protect the environment. For example, it highlighted the purchase of new aircraft with lower fuel consumption and explained how Lufthansa were one of the largest purchasers of Sustainable Aviation Fuel. The advertiser argued that the text “CONNECTING THE WORLD. PROTECTING ITS FUTURE”, in conjunction with the image used, would not be understood by consumers as an absolute statement that their services caused no harm to the environment.

The ASA said that the claim “PROTECTING ITS FUTURE” was likely, in the context in which it was presented, to be understood by consumers as an environmental claim about how the advertiser’s actions were protecting the future of the world. The ASA concluded that the ad was likely to mislead because it suggested that the advertiser had already taken significant steps to mitigate their environmental impact, whereas the initiatives described on the website linked in the ad were mainly intended to deliver results some years in the future. (Deutsche Lufthansa AG, 10 March 2023).

The ASA also investigated whether a number of claims made by another airline misleadingly exaggerated the environmental benefits of flying with them. These included “… we’re taking a louder, bolder approach to sustainable aviation”, “… you’ll earn Etihad Guest Miles every time you make a conscious choice for the planet … Environmental airline of the year”, “… we’re taking a louder, bolder approach to sustainable aviation” and “… we’re cutting back on single-use plastics and are flying the most efficient planes. Flights with a smaller footprint … Environmental airline of the year”.

The advertiser said that “sustainable aviation” had been a widely used and publicised term in the aviation industry for several years, and that it was not intended to be understood as an absolute solution to the environmental impact from air travel. They highlighted the multiple approaches they were taking and highlighted the support, certification and awards they had received from various bodies.

The ruling notes that the CAP Code requires that absolute environmental claims must be supported by a high level of substantiation (rule 11.3).

The ASA highlighted that no further explanation for the claim “sustainable aviation” was given in the advertising. While the advertiser had explained how the term was used in the aviation industry, the ASA considered it was likely to be considered an absolute environmental claim by the general public who the ad was aimed at. It concluded that the evidence which the advertiser had provided of the ongoing and proposed steps to reduce the environmental impact of their service was insufficient to support an absolute claim, and that the ads breached the Code. (Etihad Airways, 12 April 2023).

CO2 and low emissions

Marketers comparing the amount of CO2 produced per passenger with other forms of transport, should hold rigorous evidence to support their claims. They should include the source of their data and ensure that the basis of a claim is made clear.

Claims that an airline was “Europe’s … Lowest Emissions Airline” which had “low CO2 emissions” breached the Code because the ads did not make the basis of the claims clear, and because the advertiser did not provide sufficient evidence to substantiate the claims.

The ASA said the claims would be understood as comparative against other airlines, suggesting that consumers choosing this operator would be contributing lower CO2 emissions than if they had chosen to travel with any other European airline.

The ruling noted that CO2 per passenger per kilometre was an appropriate method to compare the carbon footprint of passengers on different airlines, but the ASA said that the basis of the claims should have been made clearer in the ads. In the evidence it submitted to the ASA, the advertiser referred to some of the factors that contributed to their CO2 per passenger kilometre metric but did not mention seat density, which the ASA concluded was a relevant factor likely to affect the comparison with other airlines. (Ryanair Ltd, 5 February 2020).

See also:

Travel marketing: General

Travel: Comparisons

Environmental claims: Motoring

Environmental claims: General “Green” claims 

Advertising Guidance: misleading environmental claims and social responsibility


More on