Abstract
Climate change litigation has had a dramatic rise in just a matter of years. Courts around the world are now being called upon to intervene on matters related to climate change in order to fill the gap created by legislative inaction. This article seeks to analyze the phenomenon using three key examples: The 2025 ICJ Advisory Opinion on the Legal Obligations of States Parties related to Climate Change, the trend in the jurisprudence of domestic and regional courts towards incorporating rights-based claims, and the Indian Supreme Court ruling which held the Government of India to its constitutional obligations in M.K. Ranjitsinh v. Union of India. In doing so, the article tries to highlight how the courts have been most successful when relying on the existing rights frameworks and balancing tests while also identifying the limitations of the judiciary in this context. The article ultimately posits that while litigation has proven to be an invaluable tool in ensuring that legislative and executive authorities take meaningful action on climate change, its power is severely limited by the inability to enforce its findings or propose remedial measures and should instead be seen as a catalyst for legislative and regulatory changes.
1.Introduction
Climate change litigation is a catch-all term for judicial and quasi-judicial proceedings seeking to require States, businesses, or other entities to reduce greenhouse gas emissions, adapt to a changing environment, or compensate for climate change damages. Lawsuits brought in the early 2000s, primarily tort and administrative law cases, have since proliferated with an astonishing rate, resulting in thousands of cases worldwide, in over fifty jurisdictions, as of 2026. The reasons for this are partly related to the fact that legislation on climate change is a time-consuming and politically charged process, prone to being vetoed, or reversed by new governments, while litigation is initiated and concluded by judges, who are independent from politics.
As a result, litigation has turned out to be a favored method for addressing climate change, resulting in numerous legal questions not considered before. The issues included in such lawsuits range from determining whether a certain entity is responsible for a fraction of global GHG emissions, to obtaining compensation for climate change damages suffered. Thus, the 2025 International Court of Justice Advisory Opinion on the Obligations of States in respect of Climate Change is the latest example of a court attempting to grapple with such questions.
1.1 Research Questions
This article seeks to answer three questions. First, what legal doctrines have been used to make climate-related issues justiciable in court? Second, what difference did the International Court of Justice’s (ICJ) 2025 Advisory Opinion make to the legal landscape in which climate lawsuits were operating? Third, what can the litigating experiences of the Indian, European, and American courts tell us about the opportunities and limitations of litigating climate change?
1.2 Objective and Methodology
The objective of this paper is to examine climate litigation as a source of law rather than an epiphenomenon, seeking to identify trends of constitutional and doctrinal evolution. The approach taken here is doctrinal and comparative, relying primarily on treaties, constitutional law sources, and jurisprudence, with secondary literature serving as an analytical resource.
2. From Environmental Regulation to Rights-Based Litigation
Environmental litigation has so far been largely regulatory in nature: plaintiffs have sought to annul specific administrative acts, such as a particular permit or a decision on an environmental assessment or approval of a project under relevant pollution-control statutes. Climate litigation goes beyond this in two important respects: it goes beyond administrative acts to affect directly the administrative authorities and it claims that greenhouse gas emissions are a violation of the fundamental rights, notably the right to life, health, private and family life, and intergenerational equity.
The doctrinal breakthrough came with Urgenda Foundation v. Netherlands, in which the Dutch Supreme Court held that the State's own scientific commitments under the UNFCCC framework[1] informed the standard of care owed to citizens under the European Convention on Human Rights, and ordered the government to cut emissions by at least twenty-five per cent from 1990 levels by the end of 2020.[2] The case established a template later followed, with variation, across Europe: domestic courts do not invent new climate-specific rights; they read existing civil and constitutional rights through the lens of climate science and States' own stated commitments.
This line of reasoning was further expanded upon in the regional human rights system by the European Court of Human Rights in Verein KlimaSeniorinnen Schweiz v. Switzerland. In this case, the Court held that the right to respect for private and family life, as protected under Article 8 ECHR, safeguards the right to protection from the “serious effects of climate change on life, health and well-being”, and that the respondent state had failed in its duties under Article 8 by not adopting a sufficient regulatory legal framework at the national level. The judgment in KlimaSeniorinnen is, if anything, remarkable less for the particular ruling in the case (important as it is) than for the fact that, from now on, forty-six member states of the Council of Europe will be operating under a monitored, judicially enforceable climate-governance standard.This reasoning reflects, at least in part, the influence of the regional human rights system on the domestic climate policies of states. However, the reverse is also true: the way in which states respond to their human rights obligations, or fail to meet them, also feeds back into the decisions made by the Court.
In the United States, Held v. Montana narrowed the approach down but managed to deliver a significant result, as the Supreme Court used an explicit state constitutional right to a clean and healthful environment to annul a statute which prohibited taking climate change into account when making any decisions on permits. The case illustrates that the availability of rights-based litigation for climate change is contingent upon having such a provision explicitly stated in the constitution, as a court cannot read it into the existing law.
3. International Adjudication: The 2025 ICJ Advisory Opinion
The most important recent development is the Advisory Opinion of the International Court of Justice of 23 July 2025, issued in response to a request by the UN General Assembly led by Vanuatu and other Pacific and Caribbean States.
The Court was asked two questions:
• What are the obligations of States under international law to protect the climate system from anthropogenic greenhouse gas emissions?
• What are the legal consequences when a State’s acts or omissions cause significant climate harm?
The Opinion is notable for three findings. First, the Court held that the Paris Agreement's 1.5°C temperature goal operates as a binding benchmark against which State conduct must be measured, not merely an aspirational target. Second, it confirmed that customary international law — independent of treaty commitments — imposes a due-diligence obligation on States to prevent significant transboundary environmental harm, including harm caused by cumulative greenhouse gas emissions.[3] Third, and most significant for future litigation, the Court held that a State's failure to meet these obligations can trigger the ordinary law of State responsibility, opening the door to claims for cessation and reparation where causation can be established.[4]
The Court also grounded these obligations in human rights instruments, finding that climate change threatens the rights to life, health, an adequate standard of living, and the specific rights of women, children, and indigenous peoples, and that States must act to secure the effective enjoyment of those rights.[5] A companion advisory opinion from the International Tribunal for the Law of the Sea in 2024 had already characterised greenhouse gases as a form of marine pollution under the UN Convention on the Law of the Sea, reinforcing the same due-diligence framework from a different treaty base.[6]
Advisory opinions are not binding, and the ICJ Opinion is not a decision on a dispute between specific states. The practical significance of the Opinion is that it declares what the law actually is; national courts, regional tribunals, and future ICJ cases on climate change between individual states are likely to go beyond the bare minimum standard of due diligence established by the opinion. Second, the ICJ Opinion supports the interests of small island and coastal states, which have been arguing for a considerable amount of time that they are disproportionally exposed to damage done by other countries.
4. The Indian Experience: M.K. Ranjitsinh and Constitutional Innovation
India's contribution to this jurisprudence is M.K. Ranjitsinh and Others v. Union of India, decided by a three-judge bench of the Supreme Court on 21 March 2024.[7] The case began as a species protection dispute involving the endangered Great Indian Bustard. Transmission lines that posed a threat to the bird were erected over its habitat to meet the surging demand for solar and wind energy in Rajasthan and Gujarat. The petitioners wanted the power lines to be buried in the ground.
The Court went considerably further than the facts required. It held that the right to be free from the adverse effects of climate change is a distinct fundamental right, derived from the right to life and personal liberty under Article 21 and the right to equality under Article 14, read together with the directive principle on environmental protection in Article 48A and the fundamental duty in Article 51A(g).[8] The Court noted, pointedly, that India possesses no single umbrella climate legislation, and used this legislative vacuum as part of its justification for constitutional intervention.[9]
The case demonstrates both the potential and the peril of adjudication based on rights. On the positive side, it creates a post-hoc statutory hook which is desirable by any further litigants, in the vein of the Montana and Swiss cases. However, the Court’s own attempt at reconciling the twin interests – in promoting the development of renewable energy and in preserving the local biodiversity – failed to deliver on either, and has been roundly criticised for essentially creating a hierarchy of rights, in which the only consideration was how much each was important to man. Thus, the case serves as a warning that finding a right is not necessarily advancing a remedy.
5. Corporate Accountability and Its Limits
Litigation has also targeted private emitters directly. In Milieudefensie v. Royal Dutch Shell, a Dutch court initially ordered Shell to reduce its group-wide emissions, including Scope 3 emissions from the use of its products, by 45 per cent by 2030 relative to 2019 levels, applying an unwritten standard of care derived from Dutch tort law read in light of the Paris Agreement's temperature goals.[10] The Hague Court of Appeal subsequently rejected the particular allocation of responsibility on the grounds of causation and quantification, although it did confirm the duty of care owed by Shell to reduce emissions. This highlights the issue that companies face when bringing duty of care cases; that the courts are generally more willing to accept there is a duty of care than to actually evaluate the measures required to fulfill it.
Efforts to litigate corporate and State responsibility through international human rights bodies have met a similar obstacle in the form of procedural bars. The UN Committee on the Rights of the Child declined to rule on the merits in Sacchi v. Argentina, brought by child petitioners including Greta Thunberg, on the ground that domestic remedies had not been exhausted a decision that, whatever its procedural correctness, delayed substantive engagement with the underlying claims by years.[11]
6. Findings and Discussion
Three patterns emerge from this survey. First, successful climate litigation almost always proceeds by attaching new factual content climate science, State emissions commitments to old legal vessels: constitutional rights, tort duties of care, and customary international law, rather than by asserting a freestanding right to a stable climate. Second, courts are considerably more comfortable declaring the existence of an obligation than prescribing its precise content or enforcing compliance; the Shell appeal and the practical aftermath of Urgenda both show implementation lagging well behind judicial pronouncement. Third, international and regional adjudication the ICJ and ITLOS opinions, the Klimaseniorinnen judgment is increasingly used to build a common evidentiary and doctrinal record that domestic litigants then invoke, creating a feedback loop between international and national courts that did not exist a decade ago.
There is a big difference between a right being recognized and a right being realized. India's experience with its own climate legislation is illustrative. More than a year after the passing of the order by M.K. Ranjitsinh, there is still no all-encompassing climate law, as the Supreme Court itself noted, and the expert committee that the Court ordered to submit its report has been unduly delayed on multiple occasions. In other words, the mere fact that a court has recognized a certain right as justiciable does not mean that it will be effectively implemented, as there is no system of regulation, control, and enforcement.
7. Conclusion
Climate litigation has proven to be a powerful tool to intervene in the judicial system and enforce accountability, whether at the level of the national court in the Netherlands, the Montana Supreme Court, or the CAG in India. Its successes and failures are instructive for current and future litigation at the International Court of Justice (ICJ). The main achievement of climate litigation so far has been to demonstrate that, in multiple jurisdictions, States and increasingly firms have duties under existing law to prevent climate change impacts - not innovative theory but a legal reality. Its main limitation has been that establishing the duties is one thing, but getting states to actually reduce emissions, adapt, and compensate for loss and damage, requires legislation and regulation, which litigation alone cannot deliver. It is likely that the next phase of climate litigation will focus less on the obligation to mitigate and more on how to remedy the impacts of climate change, with the causation link being key in the cases brought before the ICJ (2025).
Reference
[1]United Nations Framework Convention on Climate Change, 1992, and Paris Agreement, 2015, art. 2(1)(a).
[2]Urgenda Foundation v. State of the Netherlands, Supreme Court of the Netherlands, ECLI:NL:HR:2019:2007 (20 December 2019).
[3]Ibid., paras. 272-280.
[4]Ibid., paras. 439-443.
[5]Ibid., paras. 377-382.
[6]Request for an Advisory Opinion, Resolution of the Committee of Ministers, Commission of Small Island States on Climate Change and International Law (COSIS), International Tribunal for the Law of the Sea, Advisory Opinion, 21 May 2024.
[7]M.K. Ranjitsinh and Others v. Union of India and Others, 2024 INSC 280 (Supreme Court of India, 21 March 2024).
[8]Constitution of India, arts. 14, 21, 48A, 51A(g).
[9]Ibid., paras. 18-27.
[10]Milieudefensie et al. v. Royal Dutch Shell plc, District Court of The Hague, ECLI:NL:RBDHA:2021:5337 (26 May 2021); reversed in part, Court of Appeal of The Hague, 12 November 2024.
[11]Sacchi et al. v. Argentina et al., Communication to the UN Committee on the Rights of the Child, decided 22 September 2021 (inadmissible for failure to exhaust domestic remedies).