Climate litigation is in the spotlight again after a landmark decision last week. The top European human-rights court deemed that the Swiss government was violating its citizens’ human rights through its lack of climate action. The case, brought by more than 2,000 older women, is one of more than 2,300 climate lawsuits that have been filed against companies and governments around the world (see ‘Climate cases soar’).

But does legal action relating to climate change make a difference to nations’ and corporations’ actions? Litigation is spurring on governments and companies to ramp up climate measures, say researchers.

“There are a number of notable climate wins in court that have led to action by governments,” says Lucy Maxwell, a human-rights lawyer and co-director of the Climate Litigation Network, a non-profit organization in London.

Nature explores whether lawsuits are making a difference in the fight against global warming.

What have climate court cases achieved?

One pivotal case that spurred on change was brought against the Dutch government in 2013, by the Urgenda Foundation, an environmental group based in Zaandam, the Netherlands, along with some 900 Dutch citizens. The court ordered the government to reduce the country’s greenhouse-gas emissions by at least 25% by 2020, compared with 1990 levels, a target that the government met. As a result, in 2021, the government announced an investment of €6.8 billion (US$7.2 billion) toward climate measures. It also passed a law to phase out the use of coal-fired power by 2030 and, as pledged, closed a coal-production plant by 2020, says Maxwell.

CLIMATE CASES SOAR. Chart shows a steep increase in legal cases relating to climate change have been filed in courts since 1986.

Source: Grantham Research Institute/Sabin Center for Climate Change Law

In 2020, young environmental activists in Germany, backed by organizations such as Greenpeace, won a case arguing that the German government’s target of reducing greenhouse-gas emissions by 55% by 2030 compared with 1990 levels was insufficient to limit global temperature rise to “well below 2 ºC”, the goal of the 2015 Paris climate agreement. As a result, the government strengthened its emissions-reduction target to a 65% cut by 2030, and set a goal to reduce emissions by 88% by 2040. It also brought forward a target to reach ‘climate neutrality’ — ensuring that greenhouse-gas emissions are equal to or less than the emissions absorbed from the atmosphere by natural processes — by 2045 instead of 2050. “In the Netherlands and Germany, action was taken immediately after court orders,” says Maxwell.

In its 2022 report, the Intergovernmental Panel on Climate Change acknowledged for the first time that climate litigation can cause an “increase in a country’s overall ambition to tackle climate change”.

“That was a big moment for climate litigation, because it did really show how it can impact states’ ambition,” says Maria Antonia Tigre, director of the Sabin Center for Climate Change Law at Columbia University in New York City.

What about cases that fail?

Cases that fail in court can be beneficial, says Joana Setzer at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science.

In a 2015 case called Juliana v. United States, a group of young people sued the US government for not doing enough to slow down climate change, which they said violated their constitutional right to life and liberty. “This is a case that has faced many legal hurdles, that didn’t result in the court mandating policy change. But it has raised public awareness of climate issues and helped other cases,” says Setzer.

One lawsuit that benefited from the Juliana case was won last year by young people in Montana, says Setzer. The court ruled that the state was violating the plaintiffs’ right to a “clean and healthful environment”, by permitting fossil-fuel development without considering its effects on the climate. The ruling means that the state must consider climate change when approving or renewing fossil-fuel projects.

What happens when people sue corporations?

In a working paper, Setzer and her colleagues found that climate litigation against corporations can dent the firms’ share prices. The researchers analysed 108 climate lawsuits filed between 2005 to 2021 against public US and European corporations. They found that case filings and court judgments against big fossil-fuel firms, such as Shell and BP, saw immediate drops in the companies’ overall valuations and share prices. “We find that, especially after 2019, there is a more significant drop in share prices,” says Setzer. “This sends a strong message to investors, and to the companies themselves, that there is a reputational damage that can result from this litigation,” she says.

In an analysis of 120 climate cases, published on 17 April by the Grantham Research Institute, Setzer’s team found that climate litigation can curb greenwashing in companies’ advertisements — this includes making misleading statements about how climate-friendly certain products are, or disinformation about the effects of climate change. “With litigation being brought, companies are definitely communicating differently and being more cautious,” she says.

What’s coming next in climate litigation?

Maxwell thinks that people will bring more lawsuits that demand compensation from governments and companies for loss and damage caused by climate change. And more cases will be focused on climate adaptation — suing governments for not doing enough to prepare for and adjust to the effects of climate change, she says. In an ongoing case from 2015, Peruvian farmer Saúl Luciano Lliuya argued that RWE, Germany’s largest electricity producer, should contribute to the cost of protecting his hometown from floods caused by a melting glacier. He argued that planet-heating greenhouse gases emitted by RWE increase the risk of flooding.

More cases will be challenging an over-reliance by governments on carbon capture and storage (CCS) technologies — which remove carbon dioxide from the atmosphere and store it underground — in reaching emissions targets, says Maxwell. CCS technologies have not yet proved to work at a large scale. For instance, in February, researchers criticized the European Union for relying too much on CCS in its plans to cut greenhouse-gas emissions by 90% by 2040 compared with 1990 levels.

“There is a tendency now for companies and governments to say, we’ll use carbon capture, we’ll find some technology,” says Setzer. “In the courts, we’ll start seeing to what extent you can count on the future technologies, to what extent you really have to start acting now.”

What about lower-income countries?

There will also be more climate cases filed in the global south, which generally receive less attention than those in the global north, says Antonia Tigre. “There is more funding now being channelled to the global south for bringing these types of cases,” she says. This month, India’s supreme court ruled that people have a fundamental right to be free from the negative effects of climate change.

Last week’s Swiss success demonstrates that people can hold polluters to account through lawsuits, say researchers. “Litigation allows stakeholders who often don't get a seat at the table to be involved in pushing for further action,” says Antonia Tigre.

Maxwell thinks that the judgment will influence lawsuits worldwide. “It sends a very clear message to governments,” she says. “To comply with their human-rights obligations, countries need to have science-based, rapid, ambitious climate action.”