Sustainable aviation fuels, or SAF for short, are regarded as a more climate-friendly – albeit expensive – alternative to fossil kerosene. It therefore stands to reason that the cost of SAF should, at least in part, be passed on to travellers who, for the sake of their conscience, are willing to spend a little more money to reduce their carbon footprint. It is in the nature of things that airlines repeatedly go too far in this regard.
What does an aeroplane use for fuel?
In its judgement of 8 July 2026 – 6 U 68/25 – the Higher Regional Court of Cologne had to rule on an advertisement by an airline encouraging travellers to book sustainable aviation fuel. During the booking process on its website, the airline had advertised with the words: “With our offers for more sustainable flying, you can reduce your flight-related CO₂ emissions directly during the booking process by using sustainable aviation fuel (SAF).” It was only in a FAQ section, accessible via a separate link, that the airline clarified that the SAF purchased by customers would be incorporated into flight operations within six months of the respective booked flight.
A consumer organisation challenged this and sought an injunction against the airline, arguing that the advertising was misleading. It claimed that customers were left in the dark about when sustainable aviation fuels would be used, or at the very least were informed of this too late. It was also suggested that the specific flight booked would be made more low-emission.
The Cologne Regional Court (judgement of 21 March 2025 – 84 O 29/24) had granted the claimant’s application for an injunction at first instance. The advertising suggests that the customer can fly in a CO₂-neutral, if not climate-neutral, manner. However, the deception lies primarily in the fact that the consumer assumes that their SAF contribution relates to the specific flight they have booked.
An FAQ too late
The airline’s appeal before the Higher Regional Court of Cologne has now been dismissed. In reaching its judgement, the court did not base its decision on the question of whether the advertisement constituted advertising claiming climate neutrality. It also made it clear in this regard that the future provisions of the EmpCo Directive would not yet have any effect in the present case, as they would only be incorporated into German law at a later date.
The advertising was nevertheless unfair, however, as consumers, within the meaning of Section 5a(1), first sentence, of the Unfair Competition Act (UWG), essential information necessary to make an informed commercial decision had been withheld, and this withholding was also likely to induce the consumer to make a commercial decision that they would not otherwise have made.
In the present case, it is of considerable interest to consumers to know exactly when sustainable aviation fuels would be used. In view of the ongoing media coverage of the continuous warming of the Earth’s atmosphere—the cause of which, according to what is now a widely held scientific consensus, is human behaviour in the areas of travel, housing and industry, consumers’ concerns about their own behaviour are increasing, with the result that the desire for behaviours that reduce harmful environmental impacts is also becoming more important in consumer behaviour.
Admittedly, not all the details of a CO₂ reduction measure are always relevant to consumers. However, if it were known that SAF schemes constituted a carbon offset system separate from the actual booking, the majority of consumers would not book SAF. This information, however, was not provided in good time. The consumer must receive the information at a time when they can still take it into account in their business decision. This is not the case if the consumer first has to research the matter themselves on the website. In this instance, the clarification was only provided via a separately accessible FAQ page and was therefore too late.
Conclusion
The previous judgements on environmental advertising remain relevant even after the implementation of the EmpCo Directive into the new Unfair Commercial Practices Act (UWG) comes into force on 27 September 2026. Businesses should continue to formulate explanations of environmental claims in a clear and precise manner. It is possible to deduce from existing case law when this is not the case.