On 21 March 2025, the Regional Court of Cologne (case no. 84 O 29/24) prohibited an airline from advertising with flat-rate CO₂ compensation promises.
Facts of the case
The lawsuit was brought by a consumer protection association that objected to two advertising claims. On the one hand, travellers could “offset” their emissions from flights they had already taken by making payments to climate protection projects, and on the other hand, a surcharge could be paid during the booking process with which the company wanted to use sustainable aviation fuel (SAF) in order to “reduce flight-related CO₂ emissions”. According to the plaintiff, phrases such as “offset CO₂ emissions” or “fly more sustainably” created the impression of a complete neutralisation of the climate-damaging effects of the specific flight without disclosing the actual processes; this violated the transparency obligation under Section 5a UWG and led to misleading information in accordance with Section 5 (1) sentence 2 no. 1 UWG.
Legal standards
The Regional Court of Cologne agreed with this view. Environmental claims concern essential product characteristics and are therefore subject to strict transparency requirements. In its reasoning, the court referred to the guidelines of the Federal Court of Justice from the “Climate Neutral” judgement (BGH, judgement of 27 June 2024, I ZR 98/23), according to which advertisers must already present the basis of a claimed climate neutrality in the advertising in such concrete terms that consumers can assess the content of the measure. The statements at issue did not fulfil these requirements.
The SAF option leaves open in which quantity and on which specific flight the sustainable paraffin is used; in fact, the SAF is probably used somewhere in the group network. The impression is given that the booked flight itself is “green”, which is objectively incorrect.
The pure compensation option is even less transparent. Without information on the extent of the avoidance, the specific climate protection project, certification standards or the time period until the actual reduction in emissions, it remains unclear whether complete or only partial neutralisation is taking place. Particularly in the case of air travel – an area with a considerable greenhouse gas footprint – even minor nuances in the statement could influence consumer decisions. An average informed consumer understands “offset” or “reduce” to mean that their flight emissions are completely and simultaneously offset; if the actual effect differs from this, it is misleading.
The court therefore prohibited the defendant from continuing to use the advertising claims in question in their current form. The judgement is not yet final, but continues the previous standards of German case law for environmental advertising in the aviation and travel industry.
Practical advice
Anyone advertising climate-related benefits must state exactly what is being offset or reduced, to what extent and when. Offsetting models require a comprehensible presentation of the project types, the certificates used (such as Gold Standard or Verified Carbon Standard) and the time at which the emission savings are actually realised. When using SAF, it is not enough to purchase certificates and burn them at some point in the Group; rather, it must be clear whether the specific flight is affected or only an equivalent volume elsewhere. In addition, companies should explain which climate impacts besides CO₂ – such as nitrogen oxides or water vapour at high altitudes – are not taken into account if they are not fully addressed.
A look into the future intensifies the pressure to act: when the EU EmCo Directive comes into force on 27 September 2026, it will be prohibited throughout the EU to advertise products or services as environmentally friendly solely by means of retrospective compensation. Market participants should therefore adapt their advertising claims today and – where possible – emphasise genuine emission-avoiding measures. Transparency, verifiability and concreteness are the key words here. Only those who disclose how the advertised environmental promise is fulfilled can avoid greenwashing risks and prevent warnings under competition law.