Better call Saul: Can climate lawsuits slow global warming?

BRUSSELS - Peruvian farmer Saúl Luciano Lliuya is set to appear in a German court next week in a case against German energy utility RWE which could set a precedent for mounting legal cases against governments and companies over their climate impact.

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

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 increasingly 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, according to a report by the UN Environment Programme (UNEP) and New York's Columbia University, but the number of lawsuits is rising as well around the world including in Britain, Brazil and Germany.

A small but growing 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.

The majority of these cases are brought by NGOs and revolve around 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 the past year?

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 the Swiss government had not yet proven it is meeting its climate obligations.

In May 2024, the international ocean court ruled that 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.

In 2025, the defining legal case to watch will be the International Court of Justice and its advisory opinion on U.N. member states' obligations to combat climate change, expected later in the year.

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

But testing legal arguments takes time and money, with some cases taking up to a decade to make it to trial. NGO-led human rights cases often have to rely on a combination of donations from philanthropic organisations and individuals as well as crowdfunding and lawyers working pro bono.

This article was updated on March 11 2025, with details of the upcoming 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.)