Environmental Rights in the Courtroom
By Patricia Kameri-Mbote, Director, Law Division, UNEP
Environmental threats are intensifying worldwide, with impacts growing in both scale and frequency. Devastating floods across South and Southeast Asia, including Thailand, Indonesia, and Sri Lanka, are displacing communities, destroying homes, and undermining livelihoods. Prolonged drought and advancing desertification in North Africa are jeopardizing agriculture and food security. Rising sea levels threaten the very existence of coastal communities in Small Island Developing States. Meanwhile, air pollution contributes to a global health burden responsible for roughly nine million deaths each year. The latest United Nations Environmental Programme (UNEP)’s Emissions Gap Report 2025: Off Track finds that, under current policies, global warming is projected to reach approximately 2.8°C above pre-industrial levels by the end of the century, bringing escalating consequences with every fraction of a degree.
The environment and human rights are intrinsically linked; one can not exist without the other. As stated by the International Court of Justice (ICJ) in its landmark 2025 Advisory Opinion on ‘Obligations of States in respect of Climate Change: ‘[A] clean, healthy and sustainable environment is a precondition for the enjoyment of many human rights, such as the right to life, the right to health and the right to an adequate standard of living, including access to water, food and housing. The right to a clean, healthy and sustainable environment results from the interdependence between human rights and the protection of the environment.’
. Notably, this advisory opinion was the product of a journey that started in a classroom of law students in the Pacific to the United Nations General Assembly in New York, finding its moment of truth in the ICJ in the Hague. The journey will continue as the Advisory Opinion has far-reaching repercussions for legal frameworks and jurisprudence throughout the world.
1.1. From Paper to Reality: Recognizing Environmental Rights
While there is no universally agreed-upon definition of what constitutes ‘environmental rights’, these are traditionally understood as rights relating to the environment. As the report on Environmental Rule of Law: Tracking Progress and Charting Future Directions explains, environmental rights include rights of both humans (individually and communally) and non-humans (i.e. the rights of nature), and can include both substantive rights, such as the right to a healthy environment, and procedural rights, such as the rights to access to information, public participation and access to justice. These rights can also emerge from different sources, notablyhuman rights, constitutional rights, statutory rights, or those rights enshrined in international environmental instruments.
In the past years, the spotlight has been on the human right to a clean, healthy and sustainable environment (R2HE) due to its recognition by the United Nations General Assembly (UNGA) in 2022. This right is not new, and its roots run deep: it has been recognized at the constitutional level since the 1970s in Portugal, Spain, and Peru’s Constitutions. At the international level, a reference to human rights was made in the foundational document of the modern environmental law era: the 1972 Stockholm Declaration on the Human Environment. Since then, other countries – now 165 – have integrated the right in their national frameworks through their Constitutions, laws and accession to international or regional instruments (NYU-UNEP R2HE Toolkit).
1.2. Courts as Guardians of Environmental Justice
Courts have emerged as important avenues to ensure environmental justice. They provide access to remedies, strengthen judicial systems to ensure accountability, and spur legal innovation and reforms. Communities and individuals affected by environmental challenges, and the non-governmental organizations that represent them, have been increasingly turning to the courts and relying on their rulings to demand better implementation of environmental laws and upholding environmental rights, including the right to a healthy environment.
Courts are therefore being asked to address issues that are inherently technical and complex, and often arise because of legal gaps or the deficit in implementation and enforcement. This article provides examples of how courts are responding to environmental challenges, including through the conceptual and practical development of environmental rights.
1.2.1 Climate Litigation
Climate litigation is perhaps one of the most popular types of case-law of recent years and has been steadily increasing to be today considered a robust field of environmental law. The fourth edition of UNEP’s Global Climate Litigation Report, launched in 2025, notes that 3,099 climate change cases have been filed in 55 jurisdictions and 24 international or regional courts, tribunals, quasi-judicial bodies, and other bodies as of June 2025. The report confirms that climate cases are reaching beyond the confines of national boundaries, constructing transnational narratives, empowering grassroots movements, and mobilizing new constituencies.
For instance, the groundbreaking ICJ Advisory Opinion of July 2025 truly represented a watershed moment in international environmental law. It clarified that States have legal obligations to mitigate and adapt to climate change, grounded in climate change treaties, customary international law, and human rights law. Moreover, the opinion extended international liability to the actions of private actors within the State’s jurisdiction.
The ICJ is not the only one walking this path. It is joined by two other bodies – the International Tribunal for the Law of the Sea (ITLOS) and the Inter-American Court on Human Rights (IACtHR) – which also delivered groundbreaking advisory opinions. The latter went as far as arguing for the need and existence of a human right to a healthy climate, derived from the R2HE. A quartet of courts will be complete when the African Court on Human and Peoples’ Rights answers to a similar request, submitted by the Pan-African Lawyers Union.
The current trifecta of Advisory Opinions provides authoritative interpretations of existing international and regional legal frameworks on climate change and human rights. Together, these rulings are expanding the legal foundation for climate action, deepening accountability, and strengthening the applicability of international law.
Although there is no direct comparison across the evolution of biodiversity litigation, a study shows that a rights-based turn to biodiversity protection is taking place in 20 jurisdictions around the world (César Rodríguez-Garavito and David R. Boyd in ‘A Rights Turn in Biodiversity Litigation?’). A case before the German Federal Constitutional Court is self-identified as the world’s first constitutional complaint for better nature conservation seeking a comprehensive and effective biodiversity law (Naturschutz-Klage).
1.2.2 Right to a healthy environment
At least 100 cases globally have recognized the right to a healthy environment in the last ten years. The UNEP report on The Right to a Healthy Environment in Practice: a Decade before the Courts (2015-2025) examines trends and developments in the interpretation of the R2HE over a decade across thirty jurisdictions, including international and regional human rights bodies. Landmark cases have raised the profile of this right, including the ICJ Advisory Opinion mentioned above. The Seychelles Court of Appeal declared the right to a healthy environment as ‘the most fundamental right of a human being’ and that ‘a clean and healthy environment is a sine qua non for the meaningful expression of any other fundamental right or human right.’ (Woodlands Holdings Ltd & Anor v. Ministry of Environment Energy and Climate Change).
Further to jurisprudential recognition, the UNGA’s recognition of the right in 2022 spearheaded a global movement on the interlinkages of human rights and the environment in policy frameworks. Increasingly, international and regional instruments have included wording on the right, i.e. the UAE just transition work programme under the United Nations Framework Convention on Climate Change (UNFCCC), the Kunming-Montreal Global Biodiversity Framework under the Convention on Biological Diversity, and the Bonn Declaration for a Planet Free of Harm from Chemicals and Waste. Multiple human rights bodies, including the Human Rights Committee, the Committee on the Rights of the Child, the Committee on the Elimination of All Forms of Discrimination against Women, and twice by the Committee on Economic, Social and Cultural Rights here and here, have recognized that a clean, healthy, and sustainable environment is a precondition for the full enjoyment of other human rights, such as life and health.
Taking into account the developments at all levels, the report identifies three signals of change that could gain legal relevance and visibility in the years ahead: first, the potential transition of the R2HE from a third-generation right to customary international law; second, the application of the R2HE in new ecological and legal contexts, such as ocean ecosystems and migration and displacement; and third, the harmonization of the R2HE and economic considerations by assigning greater weight to environmental protection.
1.2.3 Rights of Nature
A unique jurisprudence has developed around the world based on non-anthropocentric rights-based approaches, also known as ‘Earth Jurisprudence’. In 2019, the UN Secretary-General considered Earth Jurisprudence ‘as the fastest growing legal movement of the twenty-first century’ (Report of Secretary-General, “Harmony with Nature” (A/74/236), 26 July 2019).
In some cases, courts invoke the rights of nature to strengthen environmental protection measures when existing environmental laws have been insufficient to effectively address environmental problems. This has happened, for example, in Bangladesh, Colombia, and India. In Ecuador, arguably the country with the most robust framework on rights of nature, courts have steadfastly ruled on nature’s rights, with the Los Cedros Forest being one of the most recent examples. At the regional level, the IACtHR has also been quite vocal on the rights of nature. In its 2025 Advisory Opinion, it stated that rights to of nature and its components ‘constitute[s] a normative development that makes it possible to strengthen the protection of the integrity and functionality of ecosystems in the long term, providing effective legal tools in the face of the triple planetary crisis and facilitating the prevention of existential damage before it becomes irreversible’ (IACtHR, ‘The Climate Emergency and Human Rights’, Advisory Opinion OC-32/25 of 29 May 2025).
1.3. The Environmental Rule of Law as a compass guiding north
Simply put, the environmental rule of law advocates for robust environmental laws and institutions that are essential to and achieving environmental goals and developing effective responses to pressing environmental crises. At the heart of the environmental rule of law are the principles of justice, accountability and fairness, which support the development of frameworks that address inequalities, ensuring that all individuals, especially people in vulnerable situations, are protected, their rights upheld and are not left behind.
As the world pays increasing attention to the need for a just transition, understanding the parallels with the environmental rule of law can be beneficial. These two terms can be interchangeable and mutually reinforcing. Both argue for protecting rights, including those of diverse stakeholders. They also require robust legal frameworks, access to justice and institutional integrity. The application of rights-based approaches supports prevention, promotes participation and access to information, enables understanding and addressing the root causes of inequality, addresses power imbalances and supports the achievement of the Sustainable Development Goals.