NEW YORK - A “climate-controlled” sausage. New trousers labelled “recycled”. A “sustainable” airline ticket.

More and more, big brands are using taglines like these to cater to their green-minded customers. And more and more, they are under fire from courts and regulators for making climate promises they cannot keep.

Researchers at the Grantham Research Institute on Climate Change and the Environment in 2023 identified “an explosion of ‘climate-washing’ cases” using existing national laws and rules.

Between 2020 and 2022, the most recent year for which statistics are available, the number of cases challenging the “truthfulness of corporate climate commitments” more than doubled, their tally found.

In 2024, this dynamic is playing out in several countries.

In Denmark, a national court in March told Danish Crown, the country’s biggest pork producer, that it is misleading to label its pork “climate-controlled”, though it declared that it is fine to assert that Danish pigs “are more climate friendly than you think”.

In Britain, also in March, the Competition and Markets Authority, a regulatory agency, looked into the climate claims of several fast-fashion brands and concluded that it is misleading to stamp a green leaf on a product and call it “recycled” without specifying how much of its content is actually recycled.

A court in the Netherlands prohibited KLM from using the slogan “fly responsibly” in its advertisements.

In the US, New York State’s Attorney-General Letitia James sued the meat multinational JBS for making “sweeping representations” about neutralising its emissions in the coming years, but offering “no viable plan”.

These cases reflect how campaigners are using an ever-wider range of national and international law to slow down climate change.

They have sued governments for failing to protect their citizens’ constitutional rights to life, and occasionally won, as in a case in Germany.

They have used human rights law to challenge governments, most recently winning a case at a regional European court.

They have sought to leverage international treaties, like the Convention on the Rights of the Child, to force governments to rein in emissions.

Complaints against alleged greenwashing are picking up.

Another database, kept by the Columbia University Law School’s Sabin Centre for Climate Change Law since 2011, found that among climate cases filed against private entities, the largest number of cases – at least 77 in total – alleged misleading advertisements.

These complaints also reflect a business imperative. Companies selling everything from toothpaste to soup are trying to meet changing consumer demands.

In the United States, sales of consumer products that are labelled green or sustainable are growing twice as fast as those that are not, according to research from New York University’s (NYU) Stern School of Business, with younger and wealthier consumers more likely than others to buy those products.

“This is a market opportunity, and companies should figure out how to make claims authentically,” said NYU’s Centre for Sustainable Business director Tensie Whelan.

The lawsuits can be a double-edged sword. They can hold firms to account, but they can also make companies trying to cut their emissions reluctant to market themselves as such.

“The easiest thing for companies is to say, ‘I just won’t say anything about it anymore or I’ll downplay what I do because that minimises the risks,’” said attorney Branda Katan, who represented KLM in the Dutch court.

JBS, the world’s biggest meat producer, is among the most closely watched of these cases in the US. Responding to the latest complaint by Attorney-General James’ office, JBS told The New York Times that it disagreed with the allegations and that it would “to help feed a growing population while using fewer resources and reducing agriculture’s environmental impact”.

The press spokesperson for Danish Crown did not return an e-mail asking for a response to the court ruling in Denmark. On its website, it explains that “climate-controlled” refers to the measures taken by pig farmers to reduce emissions from their operations.

Airlines have become a popular target of greenwashing lawsuits. An advocacy group filed a complaint against more than a dozen airlines for allegedly breaching European Union consumer protection laws, arguing that the offer of offsets is misleading because the emissions savings from offsets are “uncertain”.

An airline industry group responded to the complaint by saying that “while offsets currently play a role, their significance will diminish” as airlines develop more efficient fleets and develop alternatives to jet fuel, a heavy pollutant.

Meanwhile, three separate cases are pending in US courts against three different airlines over their use of terms like “carbon-neutral” and “sustainable”.

Energy companies are a relatively new target. In Canada, a climate advocacy group called Client Earth filed a complaint in April against FortisBC for its advertising campaign promoting what it calls “renewable natural gas”, or the methane that is captured from livestock farms and landfills.

Lawyers with Stand Environmental Society, an advocacy group, argued that the advertisements are deceptive, since most of the gas supplied by FortisBC to its customers in British Columbia for home heating comes from fossil fuels, while a small share comes from the gas captured from landfills and farms.

FortisBC issued a statement saying it disagrees with the plaintiffs’ allegations.

“FortisBC takes climate change very seriously and is taking action to help B.C. meet its climate goals,” the statement read. NYTIMES