Court proceedings in 2024 and 2025 have further reinforced the importance of legal avenues in advancing or halting climate policy action.
The largest study conducted to date concludes that cases brought before the courts by people in connection with climate change are increasingly reaching higher-instance courts.
According to data from the London School of Economics and Political Science (LSE) institute Grantham Research Institute on Climate Change and the Environment, between 2015 and 2024 a total of 276 climate-related cases reached supreme and constitutional courts. Over a longer period – from 1995 to the end of 2024 – there were slightly more than 360 such cases.
In total, the institute's databases cover the period from 1986 onwards, during which around 3,000 court cases on climate matters have taken place, giving analysts a detailed insight into how to trace the development of climate litigation and its real-world impact.
“Governments and companies need to take very seriously the legal consequences of implementing oil or gas projects, because there is a risk that these projects (and their further progress) will be examined in the courts,” says Catherine Higham, senior policy researcher at the Grantham Research Institute on Climate Change and the Environment. “The wider impact of climate litigation is becoming ever more visible and better documented. This is no longer a niche issue; it is regarded as a financial risk.”
What are the main trends in climate litigation in Europe?
“In 2024, supreme courts scrutinised new fossil fuel exploration projects in Europe ever more strictly,” the report states.
Europe's two largest oil and gas producing countries – the United Kingdom and Norway – have seen important Supreme Court rulings, and Norway suspended three North Sea oil field production licences. These cases were partly concerned with the question of whether decision-makers must take into account the emissions caused by fossil fuel projects from processing, or “scope 3” emissions (“scope 3” covers emissions that are not generated by the company itself and are not the result of the operation of assets it owns or controls, but which arise from indirectly responsible companies throughout the value chain. Examples include the purchase, use and disposal of products from suppliers), which are attracting growing attention worldwide.
Of the 2,967 climate cases filed in courts worldwide by the end of 2024, 133 were filed in the United Kingdom, the third-highest number behind the United States (1,899 cases) and Australia (164 cases).
The report's authors note that, although Europe and North America have the most cases heard by supreme courts, they have a comparatively lower success rate.
In Germany, for instance, there has been a considerable number of unsuccessful cases. These are mainly cases concerning regional legal frameworks, filed with the Federal Constitutional Court after the ruling in Neubauer, et al. v Germany, in which climate activists argued that Germany's greenhouse gas reduction targets violated their human rights.
Subsequent complaints brought by climate activists against individual German federal states were dismissed in early 2022. The court ruled that the federal states are not separately responsible for meeting national climate targets under Germany's Federal Climate Change Act, and that the claims filed therefore did not meet the constitutional admissibility criteria.
Which approach is the most successful?
Of the 276 climate cases that have reached supreme courts over the past nine years, more than 80% were filed against governments, reflecting the dominant trend of challenging shortcomings in national or regional climate policy, regulatory gaps or inaction.
Objections concerning the “integration of climate considerations”, such as scope 3 emissions, into specific projects are generally more successful (44% of cases) than cases concerning the constitutional responsibility of the “government framework”. Cases against companies can on the whole be regarded as more successful. The authors noted that around 20% of the climate cases filed in 2024 were directed against companies or their executives and officials.
“So-called corporate climate-neutrality greenwashing cases remained one of the most widely used strategies in corporate litigation in 2024,” the report's authors state, noting that there is a growing number of cases directed against the use of carbon credits to offset emissions.
What important principles have been established in climate cases?
According to the data cited in the report, the number of proceedings grounded in human rights has been growing since 2015. More and more litigants are invoking their fundamental rights in order to compel governments to act on climate change.
The 2024 judgment of the European Court of Human Rights (ECtHR) in KlimaSeniorinnen v Switzerland is a “turning point” in this field. The judgment confirmed states' obligations under international human rights and climate law, connected different legal regimes to one another and confirmed that non-governmental organisations can be parties to proceedings in climate cases. A year on, national courts have begun to apply this judgment, with mixed results. Some cases, while unsuccessful overall, have nevertheless established important principles that can be drawn upon in future.
In May 2025, Germany's Higher Regional Court dismissed Peruvian farmer Saúl Luciano Lliuya's claim against the energy giant RWE, but the ruling confirmed an important legal principle – companies can be held legally liable for the harm they cause through their impact on climate change.
A “loud” ruling also came from the International Tribunal for the Law of the Sea, which in May 2024 issued an advisory opinion stating that states have a duty to prevent, reduce and control greenhouse gas emissions from the sea.
A “two-way street” – growing numbers of cases against climate policy activity
Although the number of cases continues to grow, the overall rate of increase in climate litigation slowed in 2024. Climate litigation is becoming ever more complex, and the “firm hand” of the law is also being turned against activists and against states pursuing climate policy more actively, as political opponents make use of their influence.
“Over the past year we have observed not only the development of climate-focused strategic litigation aimed at promoting so-called climate action, but also an increase in the number of cases directed against climate policy activity, which creates new problem situations for politicians, companies and climate activists,” stresses Joana Setzer, associate professor and researcher at the LSE institute. “The situation in the United States shows that litigation is a two-way process, which can be used both to advance climate policy and to challenge it.”
Since January 2025, when Donald Trump took office as President of the United States, a wave of litigation has begun with the aim of challenging the US executive's action to roll back climate policy. Researchers note, however, that the federal government is taking an increasingly aggressive stance towards climate policy initiatives pursued by the states and has begun to bring proceedings that might be described as “anti-climate policy cases”. The battle in this area will continue and is expected to intensify.