Climate litigation typically falls into one of five broad areas of law:^[2]

• Constitutional law — focused on breaches of constitutional rights by the state.
• Administrative law — challenging the merits of administrative decision making within existing on-the-books laws, such as not granting permissions for high-emissions projects.
• Private law — challenging corporations or other organizations for negligence, nuisance, trespass, public trust, and unjust enrichment.
• Fraud or consumer protection — typically challenging companies for misrepresenting information about climate impacts.
• Human rights — claiming that failure to act on climate change or to protect related natural resources, such as the atmosphere or the rainforest, fails to protect human rights.^[4]

These areas are not static. For instance, Smith v Fonterra Co-operative Group Ltd argues for the new tort of climate change damage and the New Zealand Supreme Court duly ruled in 2024 that this novel civil wrong can be asserted in future proceedings.^[16]

The 2017 UN Litigation Report identified 884 cases in 24 countries, including 654 cases in the United States and 230 cases in all other countries combined. As of July 1, 2020, the number of cases has almost doubled to at least 1,550 climate change cases filed in 38 countries (39 including the courts of the European Union), with approximately 1,200 cases filed in the US and over 350 filed in all other countries combined.^[17] By December 2022, the number had grown to 2,180, including 1,522 in the U.S.^[18]

In the United States, Friends of the Earth, Greenpeace together with the cities of Boulder, Arcata and Oakland filed against the Export-Import Bank of the United States and the Overseas Private Investment Corporation (state-owned enterprises of the United States government), which were accused of financing fossil-fuel projects detrimental to a stable climate, in violation of the National Environmental Policy Act (case filed in 2002 and settled in 2009).^{[19][20][21][22]}

In 2017, San Francisco, Oakland and other California coastal communities sued multiple fossil-fuel companies for rising sea levels;^[23] they lost.

In 2018, the city of New York announced that it is taking five fossil fuel firms (BP, ExxonMobil, Chevron, ConocoPhillips and Shell) to federal court due to their contribution to climate change (from which the city is already suffering).^[24]

In 2020, Charleston, South Carolina, followed a similar strategy.^[25]

In June 2023, Multnomah County, Oregon sued several fossil fuel companies and industry trade groups, seeking at least $50 billion to help the county study and implement harm reduction strategies. The suit also asks for $50 million to cover past damages, and $1.5 billion in future damages. The lawsuit alleges that parties, including ExxonMobil, Chevron and the American Petroleum Institute, deceptively used "pseudo-science, fabricated doubt, and a well-funded, sustained public relations campaign" to subvert scientific consensus over the course of decades.^[26]

As of February 2020, Australia had the second most number of cases pending in the world, with almost 200 cases.^[2] Cases in Australia include Torres Strait Islanders v. Australia (2019),^[27][28] in which the United Nations Human Rights Committee found that the Australian government had violated the Islanders' human rights by failure to act on climate change, Youth Verdict v. Waratah Coal (2020),^[29] and Sharma v. Minister for the Environment (2020),^[30] in which eight young people unsuccessfully argued for an injunction against the expansion of a Whitehaven coal mine.

In June 2021, after a six year long legal battle, the Court of First Instance ruled that the climate targets of the government of Belgium are too low and therefore "breached the right to life (article 2) and the right to respect for private and family life (article 8)" of the European Convention on Human Rights.^[31]

In October 2019, a group of 15 youths filed a lawsuit against the government of Canada, claiming that the government's lack of climate change action was a violation of their rights to life, liberty and equality. The lawsuit was dismissed in November 2020.^[32]

A group of children in Colombia sued the government to protect the Amazon rainforest from deforestation due to the deforestation's contribution to climate change. In 2018, the Supreme Court ruled that the Colombian rainforest was an "entity subject of rights" requiring protection and restoration.^[33]

In 2020, an administrative court case in France, required the Macron administration to review their policies to address climate change to make sure they were significant enough to meet Paris Agreement commitments.^[34][35][36]

In 2021, Germany's supreme constitutional court ruled in Neubauer v. Germany that the government's climate protection measures are insufficient to protect future generations and that the government had until the end of 2022 to improve its Climate Protection Act.^[37]

In 2023, the Berlin-Brandenburg Higher Administrative Court said the government's action on transport and housing fell short under a law setting upper limits for carbon emissions for individual sectors. Under the ruling, Berlin must present emergency programmes to bring its policy on transport and housing back in line with the current Climate Protection Act from 2024 to 2030.^[38]

In July 2020, Friends of the Irish Environment won a landmark case against the Irish government for failing to take sufficient action to address the climate and ecological crisis.^[39] The Supreme Court of Ireland ruled that the Irish government's 2017 National Mitigation Plan was inadequate, specifying that it did not provide enough detail on how it would reduce greenhouse gas emissions.^[40]

On 5 June 2021, a group of 24 associations and 179 citizens (17 of whom were minor), led by non-profit association A Sud ('To South'), officially filed a lawsuit against the Italian government in the civil court in Rome, with the main goals of holding national institutions "accountable for the state of danger caused by [their] inertia in tackling the climate change emergency", as well as ruling that Italy must cut its greenhouse gas emissions from 1990 levels by 92% within 2030.^[41][42] This last target, which set more ambitious targets than the European Green Deal,^[42] was based on independent researches on international climate politics made by Climate Analytics and the New Climate Institute.^[41][42]

The co-plaintiffs, which included Fridays For Future members^[41] and meteorologist Luca Mercalli [it],^[41][42] were assisted by three attorneys specialized in environmental law.^[42] Other notable environmentalist organizations, including Legambiente and Greenpeace, opted not to support the lawsuit: president of Greenpeace Italy, Giuseppe Onufrio, justified the decision by stating that court cases should focus on influential companies, rather than institutions, to become more effective.^[41][42]

On 9 May 2023, Greenpeace Italy and advocacy group ReCommon, together with 12 Italian plaintiffs from several areas directly affected by climate change,^[43][44] officially announced that they would file a lawsuit against national energy company Eni, as well as the Ministry of Economy and Finance and Cassa Depositi e Prestiti (both involved as co-owners),^[43][44][45] requesting to set the beginning of the hearings in November of the same year.^[44][45] Also known as La Giusta Causa ('The Right Cause'),^[46][47] and based on the Milieudefensie et al v Royal Dutch Shell court case,^[44][45] it became the first climate lawsuit ever filed against a private-owned company in Italy.^[43][44]

The allegations focused on Eni's central role in increasing fossil fuel usage throughout the latest decades, despite being aware of the emissions' worst risks.^[43][45] A DeSmog inquiry revealed further evidence supporting the lawsuit's claims: firstly, a study commissioned by Eni itself from an affiliate research centre between 1969 and 1970, which had underlined the risk of a "catastrophic" climate crisis by 2000 posed by an unchecked rise in fossil fuel usage;^[45][46][48] secondly, a 1978 report produced by Tecneco, another company owned by Eni, which had accurately estimated that the CO₂ concentration would have reached 375-400 ppm by 2000,^[45][46] while noting that such changes to the thermal balance of the atmosphere could have had "serious consequences for the biosphere".^[43][45][46] DeSmog's investigation also found that Eni's official magazine, Ecos [it], had repeatedly included references to climate change in articles written throughout the late 1980s and 1990s, while hosting advertising campaigns wrongly claiming that natural gas was a "clean fuel".^[45][46][48]

The plaintiffs asked the court to "acknowledge the damage and the violation of [their] human rights to life, health and an undisturbed personal life" and rule that Eni must cut their emissions from 2020 levels by 45% within 2030,^[43][44] in order to reach the goals set by the Paris Agreement.^[44] In an official response, Eni's board said they would prove the lawsuit was "groundless".^[44][45]

The first hearing of the court case took place on 16 February 2024.^[47][49][50]

On 29 August 2024, the Constitutional Court of Korea ruled that the absence of legally binding targets for greenhouse gas reductions for 2031-2049 violated the constitutional rights of future generations, saying that this lack of long-term targets shifted an excessive burden to the future.^[51]

The Urgenda case is an important global precedent for climate litigation. In 2012, the Dutch lawyer Roger Cox gave the idea of judicial intervention to force action against climate change based on government targets for 2030 emissions reductions.^[52][53] In 2013, the Urgenda Foundation, with 900 co-plaintiffs, filed a lawsuit against the Government of the Netherlands "for not taking sufficient measures to reduce greenhouse gas emissions that cause dangerous climate change".^[52]

In 2015, the District Court of The Hague ruled that the government of the Netherlands must do more to reduce greenhouse gas emissions to protect its citizens from climate change.^[52][54][55] It was described as a "precedent-setting judgment"^[54] and as the "world's first climate liability suit".^[55]

In 2018, a court of appeal in The Hague has upheld the precedent-setting judgment that forces the Dutch government to step up its efforts to curb greenhouse-gas emissions in the Netherlands.^[56] In December 2019, the Supreme Court of the Netherlands upheld the ruling on appeal. Thus, affirming that the government must cut carbon dioxide emissions by 25% from 1990 levels by the end of 2020, on the basis that climate change poses a risk to human health.^[1][57]

Additional cases in the Netherlands include Milieudefensie et al v Royal Dutch Shell. The case was decided in May 2021, the district court of The Hague ordered Royal Dutch Shell to cut its global carbon emissions by 45% by the end of 2030 compared to 2019 levels,^[58] and affirmed the responsibility of the company for scope 3 emissions, e.g., emissions from suppliers and customers of its products.^[59]

In 2024, the New Zealand Supreme Court gave leave for Māori climate activist Mike Smith to sue seven corporations for their roles in causing climate change and the common law harms that resulted.^[16][60][61] Several aspects of Smith v Fonterra Co-operative Group Limited are notable. Smith argued that the principles of tikanga Māori — a traditional system of obligations and recognitions of wrong — can be used to inform New Zealand common law. Smith argued that the activities of the seven defendants — by directly emitting greenhouse gasses or supplying fossil fuels — fall under the established torts of public nuisance and negligence and a new tort of climate change damage. Smith further argued that these seven corporations are harming his tribe's land, coastal waters, and traditional culture. Smith belongs to the Northland tribes of Ngāpuhi and Ngāti Kahu. This judgment simply allows Smith to now pursue these matters in the High Court. The defendants have indicated that they will seek to convince the court that climate change responses are better left to government policy and not subject to civil litigation.

In Pakistan in 2015 Lahore High Court ruled in Asghar Leghari vs. Federation of Pakistan that the government was violating the National Climate Change Policy of 2012 and the Framework for Implementation of Climate Change Policy (2014–2030) by failing to meet goals set by the policies. In response, a Climate Change Commission was required to be formed in order to help Pakistan meet its climate goals.^[62] The case is considered significant in the history of human rights-based climate litigation.^[5]

In 2017, Saul Luciano Lliuya sued RWE to protect his hometown of Huaraz from a swollen glacier lake at risk of overflowing.^[63]

Article 56 of the constitution says that, "Everyone has the right to live in a healthy and balanced environment. It is the duty of the State and citizens to improve the natural environment, to protect the environmental health and to prevent environmental pollution." Turkey has ratified the Paris Agreement and says that its greenhouse gas emissions will be net zero by 2053, but the government has no plan to phase out coal.^[64] As of 2024 two cases have been rejected and one has been partly successful.^[65]

In 2020 and 2021 sixteen non government organizations filed lawsuits requesting the president shutdown 37 large coal-fired power stations and over 600 mines.^[66][67] In addition to climate change arguments the plaintiffs alleged that cancer cases are increased and the COVID-19 pandemic was worsened by their air pollution.^[68] The case was rejected by the 11th administrative court of Ankara for various reasons.^[69]

In 2023 young climate activists opened a case alleging that the nationally determined contribution (NDC) was inadequate.^[70][71] The three youth climate activists filed a lawsuit against President Erdoğan and the Ministry of Environment, Urbanisation and Climate Change because Turkey’s Nationally Determined Contribution is not to reduce its greenhouse gas emissions. They alleged that there is no effective climate action plan for energy. They alleged that these violate their human rights stated in the constitution, such as the environmental clause in the constitution.^[72] The Council of State rejected the case on the grounds that it was an ‘annulment of an administrative action’ case but the NDC is not an administrative action.^[65]

In 2022 and 2023 cases were brought about Lake Marmara drying up.^[73][74] In 2024 a court decided to pause the process of reclassifying the land as not wetland, on the grounds that it could be rewetted: Doğa are calling for the court to annul the reclassification.^[75]

In December 2020, three British citizens, Marina Tricks, Adetola Onamade, Jerry Amokwandoh, and the climate litigation charity, Plan B, announced that they were taking legal action against the UK government for failing to take sufficient action to address the climate and ecological crisis.^[76][77] The plaintiffs announced that they will allege that the government's ongoing funding of fossil fuels both in the UK and other countries constitute a violation of their rights to life and to family life, as well as violating the Paris Agreement and the UK Climate Change Act of 2008.^[78]

In 2022, it was claimed in McGaughey and Davies v Universities Superannuation Scheme Ltd that the directors of the UK's largest pension fund, USS Ltd had breached their duty to act for proper purposes under the Companies Act 2006 section 171, by failing to have a plan to divest fossil fuels from the fund's portfolio. The claim did not succeed in the High Court,^[79] and the claimants appealed to the Court of Appeal, being granted permission for a June 2023 hearing.^[80] The case alleges that the right to life must be used to interpret duties in company law, and that because fossil fuels must cease to exist, any investments using them pose a "risk of significant financial detriment".^[81]

In February 2023, ClientEarth filed a derivative action claim against Shell's board of directors for putting the company at risk by not transitioning away from fossil fuels quickly enough.^[82] ClientEarth said the lawsuit marked 'the first time ever that a company's board has been challenged on its failure to properly prepare for the energy transition.'^[82]

As of February 2020, the U.S. had the most pending cases with over 1,000 in the court system. Examples include Connecticut v. ExxonMobil Corp. and Massachusetts v. Environmental Protection Agency. In the United States climate change litigation addresses existing principal laws to make their claim, most of them focusing on private and administrative law. The most popular principal laws to use are NEPA (the National Environmental Policy Act), with 322 cases filed under its jurisdiction, the Clean Air Act, with 215 cases filed under its jurisdiction, the Endangered Species Act, with 163 cases filed under its jurisdiction. As more efforts continue on the front of climate change, as of August 2022, the federal government continues to approve agreements and class actions in terms of additional climate change initiatives. In addition, since 2015, there are about two dozen liability and fraud cases brought against some of the world's largest oil companies by various states for their role in denying climate policy leading to increased risks and costs borne to state governments. These states include New Jersey, District of Columbia, Delaware, Connecticut, Minnesota, Rhode Island, Massachusetts, and Vermont. Like Minnesota and the District of Columbia before it, New Jersey has also included the industry's top US trade group, the American Petroleum Institute in addition to ExxonMobil, Shell Oil, Chevron, BP and ConocoPhillips.^[83][84][85]

In the Endangered Species Act (ESA) case, Tennessee Valley Authority v. Hill, the Supreme Court stated that the ESA mandates federal agencies to insure their actions do not jeopardize any species that are listed as endangered in the ESA.^[86] Climate change litigation cases that use the ESA primarily focus on articles 7 and 9 of the statue. Article 7 states that all actions carried out by federal agencies must be unlikely to jeopardize the continued existence or result in the destruction of endangered species. Article 9 focuses not just on federal agencies but everybody, banning the taking of any endangered species by any party, be it federal, state, or private.^[86]

The first step for climate change activists is to make sure that species threatened by climate change are listed on the ESA by the Fish and Wildlife Service (FWS). Oftentimes this alone can be a lengthy process. In December 2005 the Center for Biological Diversity joined with two other US NGOs (Greenpeace and the Natural Resources Defense Council) to petition that the Arctic Polar Bear be listed on the ESA. The FWS under the Bush administration stretched the process out for years, missing many key deadlines and listing the species as "threatened" instead of endangered while the science was clearly in favor of an endangered listing. Facing mass public pressure and scientific consensus the FWS officially listed the species as endangered in May 2008.^[86]

The National Environmental Policy Act (NEPA) recognizes that actions taken by the US government can have significant environmental impact and requires that all federal agencies consider these environmental implications when doing "major federal actions". This can be done either through an environmental assessment (EA) or a more thorough environmental impact statement (EIS), how thorough the analyzation has to be depends on the nature of the proposed action.^[87][88]

The Clean Air Act (CAA) regulates air pollutants both from stationary and mobile sources. The Act was passed in the 1970s before there was widespread knowledge about greenhouse gases (GHGs) but in 2007 the Supreme Court decided the EPA did have to regulate GHGs under the CAA due to the famous Massachusetts vs. The EPA case.^[89]

In 2009 the state of California was able to use the CAA to create stronger vehicle emission standards than the national standard, which quickly led to the Obama administration adopting these stricter emission standards on a national level. These standards were called the Corporate Average Fuel Efficiency (CAFE) standards and included regulations of GHGs.^[89]

Massachusetts v. Environmental Protection Agency before the Supreme Court of the United States allowed the EPA to regulate greenhouse gases under the Clean Air Act. A similar approach was taken by California Attorney General Bill Lockyer who filed a lawsuit California v. General Motors Corp. to force car manufacturers to reduce vehicles' emissions of carbon dioxide. This lawsuit was found to lack legal merit and was tossed out.^[90][91] A third case, Comer v. Murphy Oil USA, Inc., a class action lawsuit filed by Gerald Maples, a trial attorney in Mississippi, in an effort to force fossil fuel and chemical companies to pay for damages caused by global warming. Described as a nuisance lawsuit, it was dismissed by District Court.^[92] However, the District Court's decision was overturned by the United States Court of Appeals for the Fifth Circuit, which instructed the District Court to reinstate several of the plaintiffs' climate change-related claims on 22 October 2009.^[93] The Sierra Club sued the U.S. government over failure to raise automobile fuel efficiency standards, and thereby decrease carbon dioxide emissions.^[94][95]

In 2015, a number of American youth, represented by Our Children's Trust, filed a lawsuit against the United States government, contending that their future lives would be harmed due to the government's inactivity towards mitigating climate change. While similar suits had been filed and dismissed by the courts for numerous reasons, Juliana v. United States gained traction when a District Judge Ann Aiken ruled that the case had merit to continue, and that "a climate system capable of sustaining human life" was a fundamental right under the United States Constitution.^[96] The suite was eventually dismissed.

Held v. Montana was the first constitutional law climate lawsuit to go to trial in the United States, on June 12, 2023.^[97] The case was filed in March 2020 by sixteen youth residents of Montana, then aged 2 through 18,^[98] who argued that the state's support of the fossil fuel industry had worsened the effects of climate change on their lives, thus denying their right to a "clean and healthful environment in Montana for present and future generations"^{[99]:Art. IX, § 1} as required by the Constitution of Montana.^[100] On August 14, 2023, the trial court judge ruled in the youth plaintiffs' favor, although the state indicated it would appeal the decision.^[101] Montana's Supreme Court heard oral arguments on July 10, 2024, its seven justices taking the case under advisement.^[102]

Mayanna Berrin v. Delta Airlines Inc. is a civil action lawsuit about Delta Air Lines' claim of carbon neutrality.

In 2018, ten families from European countries, Kenya and Fiji filed a suit against the European Union for the threats against their homes caused by the EU greenhouse emissions.^[103] The European Union adopted an anti-slapp directive aiming to protect human right defenders and journalists from lawsuits intended to silence them.^[104]

Verein KlimaSeniorinnen Schweiz v. Switzerland (2024)^[105] was a landmark^[106] case of the European Court of Human Rights in which the court ruled that Switzerland violated the European Convention on Human Rights by failing to adequately address climate change. It is the first case in which an international court has ruled that state inaction related to climate change violates human rights.^[107]

On 29 March 2023, the United Nations adopted a resolution calling for the International Court of Justice (ICJ) to "strengthen countries' obligations to curb warming and protect communities from climate disaster".^[108] The ICJ is expected to issue a decision clarifying legal requirements on states to respond to the climate crisis and articulating consequences that countries should face for failure to meet those requirements.^[109]

After the landmark ruling of the Netherlands in 2015, groups in other countries tried the same judicial approach.^{[110][111][23]} For instance, groups went to court in order to protect people from climate change in Brazil,^[112] Belgium,^[54] India,^[113] New Zealand,^[114] Norway,^[115] South Africa,^[114] Switzerland^[116] and the United States.^{[110][117][23]}

In Germany, a court case brought by German citizens against their government based on a newly minted human right to breathe clean and healthy air could pave the way for future legislation.^[118]

• Climate justice
• Environmental law
• Human rights and climate change
• Oslo Principles on Global Obligations to Reduce Climate Change

• Climate Change Litigation Databases, a database maintained by the Sabin Centre for Climate Change Law at Columbia Law School
• Litigation Cases, a database maintained by the LSE Grantham Research Institute on Climate Change and the Environment
• The UCS Science Hub for Climate Litigation, one aggregation of litigation-relevant resources