In March 2024, the District Court of Amsterdam ruled that 15 of 19 environmental advertising statements made by KLM Royal Dutch Airlines were misleading and unlawful, delivering the first binding court judgment against an airline for greenwashing in the Netherlands. The KLM greenwashing lawsuit ended as a declaratory victory for the environmental group Fossielvrij NL: the court found the ads unlawful under Dutch consumer protection law, but imposed no fines, no injunction, and no order to publish corrections. KLM was ordered to pay €18,211.53 in legal costs and did not appeal.
What the Amsterdam Court Ruled
The judgment came down on March 20, 2024, in Fossielvrij NL v. Royal Dutch Airlines (KLM). The court reviewed 19 specific advertising statements drawn from KLM’s “Fly Responsibly” campaign and its “CO2ZERO” carbon offset product, and it applied the Dutch Unfair Commercial Practices Act, which implements the EU Unfair Commercial Practices Directive. Fifteen statements were ruled misleading. Four were not.
The court’s governing principle was that environmental claims must be truthful, specific, and unambiguous, and that the more absolute the claim, the stronger the evidence required to support it. It drew on Articles 6:193a through 6:193j of the Dutch Civil Code and on guidance from the European Commission, the Dutch Authority for Consumers and Markets, and the Dutch Environmental Advertising Code.
The Claims the Court Struck Down
The problems the court identified cut across every layer of KLM’s environmental messaging.
- Vague sustainability language such as “Join us in creating a more sustainable future” was found to lack concrete substance, with imagery of sky, mountains, and water reinforcing a misleading impression of environmental responsibility.
- KLM’s claim that it was “committed to the Paris Agreement climate goals” was ruled misleading because the airline’s strategy depended on continued growth in air traffic, which the court found incompatible with those goals. The airline had not disclosed the tension to consumers.
- KLM painted an “overly rosy picture” of sustainable aviation fuel. At the time, SAF accounted for roughly 0.05% of total EU aviation fuel use, and the court held that calling it “sustainable” was too absolute given the technology’s early stage.
- The “CO2ZERO” branding was “too absolute and far-reaching.” It falsely implied that a passenger’s payment could fully neutralize a flight’s emissions, when reforestation and tree-planting programs had only a marginal effect on aviation’s climate impact.
- The “KLM Real Deal Days” promotion, which paired discounted fares with sustainability messaging, was found to encourage more air travel while wrapped in green language.
The Claims That Survived
Four of the 19 statements were found not misleading. These were general calls for collective action, such as “Together, we can make a bigger difference,” which the court treated as aspirational language rather than as specific environmental claims about KLM’s products.
What KLM Had to Do
Fossielvrij had asked for three concrete remedies: an injunction barring future use of the statements, an order to remove them from all media, and corrective statements to consumers. The court denied all three.
Its reasoning was practical. KLM had withdrawn the “Fly Responsibly” campaign in April 2023, after the court proceedings began, and stated it would not reuse the ads. The court found that the ads’ continued existence in news archives did not amount to “carrying advertising.” On corrective statements, it held that extensive media coverage of the lawsuit itself had already informed consumers, and Fossielvrij had not shown that people were still making purchasing decisions based on the withdrawn ads.
No fines or monetary penalties were imposed. The court did establish one forward-looking standard: any future environmental claims by KLM must be made “honestly and concretely.” But it explicitly declined to extend that requirement to “similar statements” or to issue a blanket prohibition on environmental advertising, limiting the ruling strictly to the 19 statements at issue. It also declined to require KLM to warn consumers that commercial aviation is not sustainable.
KLM did not appeal.
How the Case Got to Court
KLM had run the “Fly Responsibly” campaign with slogans including “Be a hero, fly CO2ZERO” and “CO2 neutral,” alongside imagery of nature and children. Its “CO2ZERO” product invited passengers to pay extra to offset their flight emissions through tree planting and contributions to sustainable aviation fuel.
Before the civil suit, the Dutch Advertising Code Committee (RCC) ruled on April 8, 2022, that KLM’s advertising was misleading, finding that “CO2 neutral” and “CO2ZERO” were not supported by evidence that the airline’s offset programs achieved full carbon neutralization. The RCC is a self-regulatory body, though, and its decisions are non-binding. It could recommend that KLM stop the ads but could not enforce anything or impose penalties.
Fossielvrij NL, a group focused on fossil fuel divestment and misleading emissions advertising, wanted a binding result. After a formal demand letter to KLM’s board in May 2022 drew no satisfactory response, the organization filed a class action in the District Court of Amsterdam on July 6, 2022. It was supported by Reclame Fossielvrij and by ClientEarth, which provided strategic legal support and submitted expert evidence from a senior scientist at the Stockholm Environment Institute challenging KLM’s offset claims.
When KLM argued during the case that Fossielvrij lacked standing because the ads had been pulled, the court rejected the argument, holding that a request for a formal declaration of unlawfulness gave the organization a valid legal interest whether or not the specific ads were still running.
What the Ruling Has Changed
The declaratory nature of the judgment meant KLM walked away without meaningful financial consequences, but the ruling has been used aggressively as leverage against other airlines and companies.
In July 2024, ClientEarth and Fossielvrij sent legal warning letters to 71 other airlines operating out of Amsterdam’s Schiphol Airport, arguing that advertising claims about sustainable aviation fuels, carbon offsetting, and net-zero-by-2050 targets were likely unlawful under the standards the court had set. In April 2024, the European Commission sent letters to 20 airlines demanding they identify potentially misleading green claims and comply with EU consumer law within 30 days. By November 2025, 21 airlines, including KLM, Air France, Lufthansa, Ryanair, and EasyJet, had agreed to reform their environmental marketing. They committed to stop claiming that flight emissions can be “neutralised, offset, or directly reduced” through passenger contributions to climate projects or alternative fuels, to avoid vague environmental language, to provide specific timelines and evidence for net-zero goals, and to make carbon calculators transparent.
The EU also tightened the underlying law. The Empowering Consumers Directive, adopted in February 2024, bans claims that a product has a “neutral, reduced, or positive impact” on the environment based on greenhouse gas emissions offsetting. Terms like “climate neutral,” “carbon positive,” and “climate net zero” will be prohibited unless backed by independently verified evidence. Member states must transpose the directive by March 2026, with enforcement starting in September 2026. Violations can carry fines of up to 4% of turnover or €2 million for widespread infringements.
The ruling has also been cited in cases outside aviation and outside the Netherlands. In October 2025, the Judicial Tribunal of Paris ruled in Greenpeace France and Others v. TotalEnergies that the oil company misled consumers by advertising an “ambition to achieve carbon neutrality by 2050” while continuing to expand fossil fuel production. The court ordered TotalEnergies to remove the offending claims, publish the judgment on its homepage for 180 days, and pay damages to the three plaintiff NGOs. TotalEnergies said it would not appeal. In the United States, a California class action against Delta Air Lines over its “world’s first carbon-neutral airline” claim survived motions to dismiss and, as of October 2025, was in the class certification phase, with the court holding that the Airline Deregulation Act does not preempt state consumer protection claims regarding carbon-neutrality representations.
The core principle drawn from Amsterdam, that companies advertising commitment to climate goals must ensure those claims are feasible and concrete rather than aspirational, has become the benchmark subsequent greenwashing cases are measured against.