Better call Saul: Can climate lawsuits slow global warming?

BRUSSELS - A German court rejected a Peruvian farmer's appeal for damages against RWE, the German energy utility he accused of putting his home at risk through climate change, but ruled companies were liable for their emissions - an important legal precedent.

The nearly decade-long battle concerned whether the company's carbon dioxide emissions could be blamed for Andean glaciers melting above Saúl Luciano Lliuya's hometown and swelling a lake to dangerous levels.

But the judge in the German city of Hamm said the estimated risk of damage to his house was not enough to take the case further and ruled no appeal was possible.

The judge added, however, that had there been a larger adverse effect, a polluter could have been made to slash emissions or pay damages.

Activists, scientists and Indigenous people are filing a growing number of lawsuits against governments and fossil fuel companies to try to slow global warming by holding them to account for climate-driven impacts like extreme weather.

Dubbed "climate lawfare", the total number of such cases has more than doubled since 2015 to more than 2,000 in 2024, according to Climate Change Laws of the World, a database of climate change legislation and policies around the globe.

What is climate change litigation and where is it happening?

Individuals or groups have taken governments or companies to court to spur climate action, such as phasing out fossil fuels and reducing harmful emissions.

Climate litigation can also refer to the growing number of legal disputes between investors and states that arise because international treaty provisions allow energy firms to sue governments when their carbon-cutting programmes affect profits.

Most cases - more than 1,700 - have been filed in the United States, the U.N. Environment Programme and New York's Columbia University said in a report, but the number of lawsuits is also rising elsewhere, including in Britain, Brazil and Germany.

A small number of environmental and climate disputes have been brought before courts in Africa, with 10 cases in South Africa, three in Nigeria and two in Kenya in the past 15 years.

Most of these cases are brought by NGOs and concern environmental impact assessments, often for the construction of coal-fired power plants, but also include cases addressing issues such as the right to clean air and water.

Which climate cases have marked legal milestones in recent years?

More than 2,000 Swiss women aged over 64 brought a case in 2023 accusing their government of violating their human rights by failing to do enough to combat climate change and putting them at risk of dying during heat waves.

The European Court of Human Rights in April 2024 upheld their complaint, a decision likely to set a legal precedent. In March, the Council of Europe, the court's oversight body, said Switzerland had not yet proven it was meeting its climate obligations.

In May 2024, the International Tribunal on the Law of the Sea ruled greenhouse gas emissions absorbed by the ocean are a form of marine pollution, subject to international controls.

In the first U.S. youth-led climate case to reach trial, 16 plaintiffs, aged between two and 18, filed a lawsuit against the state of Montana over policies prohibiting state agencies from considering climate impacts when approving fossil fuel projects.

A judge ruled in the plaintiffs' favour in 2023, citing a provision in the state constitution requiring Montana to protect and improve the environment. The decision was upheld by Montana's top court in December 2024.

Can climate litigation drive change?

Court victories for campaigners are likely to spur more cases, and the legal precedents already set make it more likely that similar lawsuits will prevail.

The defining legal case expected sometime this year will be the International Court of Justice and its advisory opinion on U.N. member states' obligations to combat climate change.

Though not legally binding, it has legal weight and moral authority, and could influence future climate litigation and government policy to uphold climate commitments.

A group of NGOs have also brought a case against French energy giant TotalEnergies alleging a company rebrand amounted to "greenwashing" with misleading environmental claims.

It builds on a case won against Dutch airline KLM in 2024 over misleading consumers about the environmental impact of air travel.

But testing legal arguments takes time and money, with some cases taking up to a decade to make it to trial.

This article was updated on May 28 2025, with details of the court case against RWE.

(Reporting by Joanna Gill with additional reporting from Nita Bhalla, David Sherfinski and Andre Cabette Fabio and Anastasia Moloney; Editing by Jon Hemming.)