Danish court fines KLM over misleading 'sustainable travel' advertising

Consumers across Europe could soon see more honest environmental advertising after a Danish court ruled that KLM Royal Dutch Airlines misled customers with claims about the sustainability of its flights. The decision strengthens efforts by regulators to ensure companies provide accurate climate information instead of overstating their environmental progress.

The Copenhagen court ordered KLM to pay 3 million Danish kroner (around $460,000) after finding that the airline’s advertising gave passengers a misleading impression about the environmental impact of flying. The ruling follows a complaint filed by Denmark’s Consumer Ombudsman, the country’s independent authority responsible for protecting consumers from unfair marketing practices.

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At the centre of the case was a 2023 advertising campaign broadcast on radio and Spotify. In the campaign, KLM described its services as “a big step forward towards slightly more sustainable travel” and told customers it would use “a larger share of sustainable aviation fuel for all tickets from now on.”

However, the court concluded that the campaign exaggerated the airline’s environmental progress. Judges found that many consumers could have believed flying with KLM had become significantly better for the climate than it actually was.

One of the court’s key findings focused on the airline’s use of Sustainable Aviation Fuel (SAF). Despite KLM’s advertising, SAF accounted for only 1% of the airline’s total fuel consumption at the time. Judges ruled that such a limited contribution could not justify the broad sustainability claims made in the advertisements.

Sustainable Aviation Fuel is widely regarded as one of aviation’s most promising tools for reducing carbon emissions because it can cut lifecycle greenhouse gas emissions compared with conventional jet fuel. However, global production remains limited, making it available in relatively small quantities for most airlines.

The Danish ruling is not the first legal setback for KLM over its environmental marketing.

In 2024, the District Court of Amsterdam ruled that the airline had presented an overly optimistic picture of its sustainability efforts. That case, brought by Dutch climate campaign group Fossielvrij NL, challenged KLM’s claims about sustainable aviation fuel, carbon reduction measures and tree-planting programmes.

The Dutch court concluded that while these initiatives could reduce emissions to some extent, their overall impact remained limited. It warned that such advertising could wrongly create the impression that flying had become environmentally sustainable.

The latest judgment reflects growing pressure on companies across Europe to ensure environmental claims are backed by clear scientific evidence.

Regulators are paying closer attention to businesses that promote products or services as environmentally friendly without providing sufficient proof. The practice, widely known as greenwashing, has become a major concern across industries including aviation, fashion, energy and consumer goods.

Environmental experts argue that exaggerated sustainability claims can prevent consumers from making informed purchasing decisions. As climate awareness grows, customers increasingly rely on company advertising when choosing products and services they believe have a lower environmental impact.

For airlines, the challenge is particularly significant because aviation remains one of the world’s most carbon-intensive industries. Although carriers are investing billions of dollars in cleaner aircraft technologies, sustainable fuels and operational improvements, experts say meaningful emission reductions will require large-scale technological advances and increased production of low-carbon fuels.

KLM said it had “taken note” of the Danish court’s decision.

The ruling reinforces a growing legal trend across Europe requiring businesses to ensure environmental marketing is specific, measurable and supported by evidence. Courts have made it clear that companies cannot present high-emission activities as environmentally friendly simply because they have introduced relatively small sustainability measures.

The decision is expected to influence how airlines and other major corporations communicate their climate ambitions in future advertising campaigns. As regulators continue to tighten oversight, companies may face greater legal and financial risks if environmental claims cannot be fully substantiated.