What is climate change litigation?
Different ways climate change litigation is defined
There are many ways to define climate change litigation, which is often referred to as simply ‘climate litigation’, but one point all definitions have in common is that cases must relate to climate change in some way. How direct and substantial this connection is generally indicates whether climate litigation is being defined along broader or narrower terms.
One way to visualise these definitional parameters is through Peel and Osofsky’s (2020) diagram of concentric circles (Figure 1 below). At the centre sits the narrowest definition: litigation that features climate change as a central issue in the case. An example of this is a case recently heard before the European Court of Human Rights, where applicants challenged the adequacy of Switzerland’s national climate policy response. Under the broadest interpretation in this conception is litigation that may hold implications for mitigating or adapting to climate change but that is not ‘framed’ along such terms (the outer circle). Examples include challenges to excessive gas flaring or industrial air pollution, where reducing emissions generated by the challenged activity is not a motivating factor for bringing the case but would be positive for the climate.
Figure 1. Visualising the definitional parameters of climate litigation
Source: Peel and Osofsky (2020)
Broader definitions have been criticised for creating ambiguity regarding which cases fall within scope. As climate change has economy-wide impacts, and many human activities influence climate change, a very broad approach could include almost any case in the world. Extracting any meaningful insights from such a large and heterogenous body of cases would be very challenging. On the other hand, narrower definitions may create regional imbalances in the corpus of climate cases. Cases filed in high-income countries of the Global North often tend to feature more explicit climate change arguments than those filed in emerging markets and developing economies in the Global South. Reframing definitional parameters around a typology of adaptation-related climate risks (such as droughts and flooding) could more accurately capture how litigation in some jurisdictions in the Global South is responding to the threats posed by climate change.
Is there a definition that is commonly used?
A widely used definition stems from the approach adopted by the Sabin Center for Climate Change Law at Columbia University, which uses two criteria to identify cases for its Climate Litigation Database: i) a case should have been brought before a judicial body (although certain examples of administrative matters or investigation requests are included); and ii) climate change law, policy or science must be a material issue of law or fact in the case. Under this definition, by the end of 2025, more than 3,600 cases had been filed around the world.
The Sabin Center’s database is the most comprehensive source on developments in global climate litigation. However, other resources also exist, some with broader definitions of climate litigation – see Table 1.
Table 1. Data sources for climate litigation
| Data source | Type of database (geographical/thematic focus) |
| Brazilian Climate Litigation Platform maintained by the Research Group on Law, Environment and Justice in the Anthropocene (JUMA) at PUC-Rio | National – Brazil |
| Climate Litigation Database maintained by the Cluster of Excellence on Climate, Climatic Change, and Society (CLICCS) at the University of Hamburg | National – Germany |
| Australian and Pacific Climate Change Litigation database maintained by the University of Melbourne | Regional – Australia, New Zealand and Pacific Islands |
| Climate Litigation Platform for Latin America and the Caribbean database maintained by AIDA | Regional – Latin America and Caribbean |
| CLX Casebook maintained by the Climate Law Accelerator at New York University | Thematic – human rights |
| Climate Rights Database maintained by the University of Zurich | Thematic – human rights |
| Just Transition Litigation Tracking Tool maintained by the Business and Human Rights Resource Centre | Thematic – human and environmental rights in transition mineral mining or renewable energy projects |
| Climate Mobility Case Database maintained by the Global Strategic Litigation Council | Thematic – climate-related (im)mobility |
| Youth Climate Justice Case Law Database maintained by University College Cork | Thematic – youth |
| Youth Climate Lawsuits Database maintained by ClimaTalk | Thematic – youth |
Evolution of climate litigation over time
One of the first climate litigation cases was filed in the United States in 1986, contesting a federal agency’s decision not to evaluate the impact of its fuel economy standards on global warming. Over time, the litigation landscape has evolved, as a confluence of factors has created fertile ground for legal challenges to be brought against an expanding array of public and private actors. Some academics refer to three waves of litigation:
- The first wave began in the 1980s in Australia and the US, largely consisting of challenges to administrative processes that had failed to adequately assess what effects a policy or decision would have on climate change.
- The second wave, from 2007, followed an increase in public awareness of the consequences of climate change and more legislation to reduce greenhouse gas emissions after negotiation of the Kyoto Protocol.
- The third wave, from 2015, has seen a surge in litigation facilitated through coinciding factors such as the signing of the Paris Agreement in 2015, developments in climate research, including Richard Heede’s ‘Carbon Majors’ report and attribution science, and the emergence of a transnational movement seeking to hold governments and private actors legally accountable for inaction on climate change. One of the most significant features of third wave litigation is the use of human rights and constitutional law arguments. The groundbreaking cases Leghari v. Pakistan, Urgenda Foundation v. State of the Netherlands, and Juliana v. United States typify this so-called ‘rights turn’.
Cases extend across the three waves. For example, the administrative challenges that are characteristic of the first wave continue to be brought in many jurisdictions today, even as novel, rights-based cases are tested in the courts. However, while first and second wave cases focused on government and corporate actors most closely associated with contributing to the climate crisis (e.g. fossil fuel companies), third wave-style litigation is targeting private actors from an increasingly diverse range of sectors, including the food, agriculture and finance sectors. In parallel, the climate legislation landscape has evolved too, and inadequate or insufficiently ambitious laws and policies have frequently been the subject of legal challenges.
Scientific evidence plays a key role in helping courts adjudicate cases about government and corporate responsibility for addressing climate change. As climate science evolves, resources like the Grantham Climate Litigation Guides and the Union of Concerned Scientists Glossary have emerged to help legal professionals, policymakers, researchers and scientists navigate interactions between climate science and climate law.
What types of behaviour might cases challenge?
Over time, climate litigation has been used strategically as a tool to influence policy outcomes or to change corporate and societal behaviour. Strategic climate litigation builds on learning from a long history of strategic human rights and environmental litigation, where a case is often seen as part of a broader advocacy strategy for policy reform.
The Grantham Research Institute has been publishing the annual Global Trends in Climate Change Litigation snapshot series since 2019, drawing on the Sabin Center’s Climate Litigation Database. In this series, we have developed a typology of the types of behaviour that cases seek to discourage or incentivise – see Table 2 for examples.
Table 2. Case strategy types (identified by the Grantham Research Institute)
| Strategy type | Illustrative example |
| Government framework cases which challenge the ambition or implementation of climate targets and policies affecting an entire economy and society. | Verein KlimaSeniorinnen Schweiz and Others v. Switzerland |
| Integrating climate considerations cases which challenge decisions on the grounds that climate considerations, evidence, standards or principles have been ignored, incorrectly assessed or inadequately applied. | Finch v. Surrey County Council |
| Systemic polluter pays cases which allege that a company’s business operations have contributed to global emissions and seek damages because of climate-related harm. | Luciano Lliuya v. RWE |
| Incidental polluter pays cases which challege that a localised unlawful action (e.g. illegal deforestation or unlicensed facility operation) has led to emissions and damage to the climate system. | MPF v. Oliveira Lima |
| Corporate framework cases which seek to develop standards preventing companies from continuing with high-emitting activities by requiring changes in group-level policies, corporate governance and decision-making extending through the companies’ operations. | Milieudefensie v. Shell |
| Failure-to-adapt cases which challenge a government or company for failure to take climate risks into account. | R (Friends of the Earth Ltd, Mr Kevin Jordan and Mr Doug Paulley) v. Secretary of State for Environment, Food & Rural Affairs |
| Transition risk cases which concern the (mis)management of transition risk by directors, officers and others tasked with ensuring the success of a business. | Kim Min et al. v. Kim Tae-Hyun et al. |
| Climate-washing cases which challenge inaccurate government or corporate narratives regarding contributions to the transition to a low-carbon future. | Australasian Centre for Corporate Responsibility v. Santos Ltd |
| ‘Turning off the taps’ cases which challenge the flow of finance to projects and activities that are not aligned with climate action. | Milieudefensie v ING |
Are all cases supportive of climate action?
Not all climate litigation seeks to advance climate action goals. While many cases can be understood as ‘pro-climate’ or ‘climate-aligned’ litigation, some cases can also be understood as ‘anti-climate’ or ‘anti-regulatory’ litigation. However, over time, this distinction has become increasingly nuanced, with the emergence of cases that seek to challenge the way climate action is being designed or implemented, rather than opposing the need for such action. These cases have been referred to as ‘non-climate-aligned’ litigation, and include just transition litigation (i.e. cases brought by workers, communities and Indigenous peoples who bear disproportionate burdens of the low-carbon transition) and green v. green cases, which challenge climate policies or projects on the grounds of their impacts on other environmental values, particularly biodiversity.
Is climate litigation having a wider impact on climate change goals?
In 2022, the Intergovernmental Panel on Climate Change (IPCC) recognised that climate litigation has influenced the outcome and ambition of climate governance. Outcomes in court are only one part of the picture. A precise understanding of the scope of this influence is currently lacking but there is general academic consensus that litigation plays a significant role in inducing broader policy and societal changes, and that access to courts is vital to hold actors accountable when they fail to take adequate steps to advance climate action.
Climate litigation can impact diverse range of stakeholders across time horizons. There is a growing empirical evidence illustrating such impacts on legislation and policy frameworks, financial markets and investors’ risk perception, and social movements.
Ultimately however, on its own, litigation cannot replace the laws and policies that are essential for driving ‘all-of-society’ approaches to transitioning to resilient, decarbonised economies.
This Explainer was updated by Tiffanie Chan in September 2026. The preceding version was written by Emily Bradeen, with review by Joana Setzer, Catherine Higham, Georgina Kyriacou and Sam Kumari.