International Judicial Advisory Opinions, Ocean Rights, and the Legal Wave for Ocean Care
The world is experiencing an unprecedented moment of judicial involvement with the climate crisis. Within the span of 14 months, three international courts responded to requests to clarify states’ legal obligations on climate change:
The Commission of Small Island States (COSIS) requested the International Tribunal for the Law of the Sea (ITLOS) to give an interpretation of obligations under the UN Convention on the Law of the Sea (UNCLOS).
Chile and Colombia requested the Inter-American Court of Human Rights (IACHR) to clarify how climate inaction may violate human rights.
A coalition of youth activists and states led by Vanuatu requested the International Court of Justice (ICJ) to give an authoritative statement on states’ duties to protect current and future generations from climate harm.
- Advisory Opinion (July 2025)
Together, these efforts and the courts’ opinions mark a turning point for environmental governance. They suggest that climate action is no longer just a political choice but a legal duty. This emerging legal wave could strengthen accountability and bridge the gap between environmental principles and practice. Because the health of the ocean underpins the planet’s climate stability, these advisory opinions may also reinforce a new legal and moral framework for ocean protection.
I. What Is an Advisory Opinion?
Parliament of Vanuatu, state leader of the request to the International Court of Justice for an advisory opinion on states’ obligations in relation to climate change. Photo credit: Phillip Capper from Wellington, New Zealand, CC BY 2.0, via Wikimedia Commons.
An advisory opinion is a formal legal clarification issued by an international court at the request of states or international organizations. While not legally binding in the same way as a judgment between parties, advisory opinions carry significant moral and interpretative authority.
They clarify existing treaty obligations and customary international law, guide states’ behavior, inform negotiations and litigation strategies, and provide moral and legal support to domestic courts and civil society organizations seeking to hold governments or corporations accountable.
The current wave of advisory opinions represents a coordinated global effort to define the boundaries of lawful conduct in an era of climate crisis. For the first time, international courts are being asked to spell out, in legal terms, what states must do to curb greenhouse gas (GHG) emissions, protect the ocean, and safeguard the rights of future generations.
II. Climate Obligations Beyond Politics
a) The Ocean–Climate Connection
The ocean covers more than 70 percent of Earth’s surface and is the planet’s largest climate regulator. It absorbs over 90 percent of the excess heat generated by human-caused emissions and around a quarter of our carbon dioxide output. Yet these services come at a cost: the ocean is warming, acidifying, losing oxygen, and nearing ecological tipping points.
Rising sea temperatures drive coral bleaching and biodiversity collapse. Melting ice and thermal expansion cause sea levels to rise, threatening the very existence of island nations. Ocean acidification undermines shellfish, plankton, and coral, the foundations of marine food webs.
In legal terms, this ecological reality translates into obligation. Protecting the ocean is not simply an act of environmental benevolence, it is integral to fulfilling states’ climate and human rights duties. As the ITLOS request argues, GHG emissions constitute a form of marine pollution under UNCLOS, a groundbreaking assertion that places ocean protection squarely within the framework of international law.
This linkage between the ocean and climate has also entered the public imagination. The recent documentary Ocean, featuring David Attenborough, has helped transform people’s perceptions of the ocean from a distant resource into a living system central to Earth’s stability. By documenting destructive practices previously hidden from public view, such as bottom trawling, the film brings into focus how “out of sight, out of mind” activities are degrading marine ecosystems. It illustrates how science and storytelling can converge with law, and shows that safeguarding the ocean is essential to sustaining life itself.
b) Advisory Opinions: Elevating Climate Beyond Politics
For decades, international climate action has been trapped in the realm of voluntary pledges, political negotiation, and uneven implementation. Under the Paris Agreement, countries agreed to substantially reduce GHG emissions to enable the long-term global average surface temperature increase to be kept well below 2°C above pre-industrial levels and pursue efforts to limit it to 1.5°C. The advisory opinions offer an important reframing. They affirm that limiting temperature rise to 1.5°C is not just a policy goal but a legal requirement grounded in human rights, environmental law, and the law of the sea.
The IACHR request positions climate inaction as a violation of rights to life, health, food, and culture, especially for Indigenous and coastal communities. The ICJ request extends this reasoning globally, asking the Court to clarify how states’ obligations under existing law, such as the duty to prevent transboundary harm and to act with due diligence, apply to GHG emissions.
By treating climate protection as a duty, the resulting opinions could reshape how international law is interpreted and enforced. They strengthen the normative foundation for ambitious national policies—for example, the IACHR opinion marked the first time an international court recognized the Rights of Nature—and support domestic courts seeking to hold states and corporations accountable.
Equally important, they embed the principle of intergenerational justice, the idea that states owe a duty of care not only to present citizens but also to future generations. This is a moral and legal evolution long championed by youth activists and small island nations that face existential threats.
c) The Broader Influence: From Treaties to Transformation
The waves of consequences of these advisory opinions are likely to extend far beyond the courtroom. Their influence could reach into international negotiations, national policymaking, and the implementation of existing treaties.
At COP30 in Brazil and subsequent climate COPs, the opinions should encourage states to strengthen their Nationally Determined Contributions (NDCs) and align them with clarified legal obligations. NDCs, which represent each country’s self-determined climate action plan under the Paris Agreement, outline the measures through which states intend to reduce GHG emissions and adapt to the impacts of climate change. Such alignment would mark a significant shift in the tenor of international climate diplomacy, transforming it from a process based on voluntary ambition to one grounded in legal compliance and accountability.
They could also provide an incentive for countries to enhance their National Biodiversity Strategies and Action Plans (NBSAPs) under the Kunming–Montreal Global Biodiversity Framework. NBSAPs are national plans for protecting and sustainably managing biodiversity, setting country-specific targets and actions, and outlining how progress will be tracked. While NBSAPs focus on biodiversity and ecosystems, NDCs are centered on cutting greenhouse-gas emissions and adapting to climate change. By incorporating ocean protection measures into these strategies, states can demonstrate that biodiversity and climate are interconnected responsibilities rather than separate agendas.
In the negotiations for a Global Plastics Treaty, the opinions lend legal and moral weight to the argument that plastic pollution and GHG emissions are part of the same systemic challenge. Both originate largely from fossil fuel production and both undermine the health of the ocean. Recognizing this interconnection could amplify calls for a binding global commitment to phase out fossil-based plastics and reduce emissions across the plastics lifecycle.
Finally, the advisory opinions can guide the implementation of the High Seas Biodiversity Treaty (BBNJ), which has now been fully ratified and enters into force on January 17, 2026. They clarify how states’ obligations to protect marine biodiversity intersect with climate and human rights law. This guidance could shape conservation measures, benefit-sharing frameworks, and environmental impact assessments under the new treaty, ensuring that implementation aligns with broader principles of ocean stewardship and climate justice.
Taken together, these developments demonstrate that advisory opinions are not isolated exercises in legal interpretation. They are catalysts for transforming how the global community governs the relationship between people, the ocean, and the climate.
III. Oceans as a Legal and Ecological Anchor
The ITLOS advisory opinion request by COSIS represents a landmark shift. By framing GHGs as a form of marine pollution, ITLOS recognizes that climate change directly violates obligations under UNCLOS to protect and preserve the marine environment. This interpretation elevates ocean protection from a peripheral issue to the heart of global climate accountability.
Meanwhile, the IACHR and ICJ advisory proceedings expand the conversation by linking ocean degradation and climate harm to human rights violations. For millions of coastal and island residents, climate impacts are not abstract; they threaten homes, livelihoods, and cultural survival.
Beyond the courts, a growing movement is pushing to recognize the ocean as a rights-bearing entity. Earth Law Center’s Ocean Program, alongside global partners, advocates for a Universal Declaration of Ocean Rights by 2030. This initiative builds on existing Earth law principles that recognize ecosystems as subjects of law with inherent rights to exist, thrive, and regenerate.
Practical steps toward this vision include legal toolkits for recognizing ecosystem rights and campaigns like A Voice for the Deep, which elevate the perspective that the ocean is not property but a living system that sustains all life.
At the national level, countries from Ecuador to New Zealand have already embedded Rights of Nature into constitutional or statutory frameworks. These approaches complement the advisory opinions’ logic: if states have a duty to prevent harm to the environment for the sake of human rights, extending recognition to the rights of ecosystems themselves is simply the next step forward.
Together, these developments are driving a transformation from governing the ocean as a “resource” to acknowledging it as a legal and ecological community with intrinsic value and standing.
Conclusion: The Legal Wave for Ocean Care
Advisory opinions do not create new laws, and the danger remains that these recent landmark opinions will not achieve the conservation and humans rights effects we so desperately need. The opinions do, however, clarify and strengthen the ones we already have. They illuminate how existing human rights, environmental, and maritime obligations intersect, and they redefine climate and ocean protection as enforceable duties.
For advocates, policymakers, and courts, these opinions provide a powerful toolkit for accountability. They can inform stronger NDCs, reinforce biodiversity and plastics negotiations, and inspire domestic recognition of ecosystem rights.
Most importantly, they signal a deeper cultural shift. The law is beginning to echo what science and Indigenous worldviews have long communicated: the ocean is alive, and our fate is bound to its wellbeing.
This emerging legal wave is not just about compliance; it is about transformation. By grounding climate and ocean care in legal obligation and moral responsibility, the world’s courts are helping humanity take a historic step toward a truly Earth-centered governance system.
The ocean, once treated as the planet’s silent absorber of excess heat and harm, is now finding its voice in law. As that voice grows stronger, it calls us toward a future where care for the blue planet is our collective legal and ethical duty.
