For decades, climate change has been framed as a scientific challenge, a political puzzle, and a moral dilemma. But now, it’s entering a new arena—the courtroom. In a ground breaking move, a top United Nations court has ruled that countries can sue each other over climate change, a development that could reshape the entire landscape of global environmental accountability.
This decision isn't just symbolic. It sets the stage for something tangible: legal responsibility for climate damage. For vulnerable nations—especially those already suffering from rising sea levels, extreme weather, and ecological collapse—this is more than a win. It’s the long-awaited beginning of justice.
Let’s take a deep dive into this historic ruling, why it matters, who’s involved, and what it could mean for the future of our planet.
The Court Behind the Ruling: What is ITLOS?
The International Tribunal for the Law of the Sea (ITLOS), based in Hamburg, Germany, is a little-known but powerful UN-affiliated court that deals with issues relating to the oceans and maritime law. It was established under the United Nations Convention on the Law of the Sea (UNCLOS).
On May 21, 2024, ITLOS issued a historic advisory opinion in response to a request made by a coalition of small island nations who face existential threats from climate change. These nations wanted to know: Can countries be held legally accountable under international maritime law for greenhouse gas emissions that affect the ocean?
The court’s answer: Yes.
You can read the official advisory opinion here: ITLOS Advisory Opinion 2024
What the Court Actually Said
ITLOS determined that countries have a legal obligation under the Law of the Sea to prevent, reduce, and control marine pollution, including pollution from greenhouse gases that cause ocean warming, acidification, and sea level rise.
The ruling clarified:
-
Greenhouse gas emissions count as marine pollution when they affect the ocean.
-
All countries have a duty of due diligence, meaning they must take reasonable actions to avoid harming the marine environment.
-
Big emitters can be held accountable if their emissions cause damage to other countries’ marine resources or coastlines.
This ruling doesn’t immediately force countries into court. Instead, it provides a legal basis for future litigation or negotiations. It essentially says: “Yes, you can sue—and here’s the legal framework to back it up.”
Who Brought the Case Forward?
This legal breakthrough was driven by a small but mighty coalition: the Commission of Small Island States on Climate Change and International Law (COSIS). Formed in 2021, this group includes nations like Tuvalu, Antigua and Barbuda, Palau, Saint Lucia, and others.
These island nations face direct, imminent threats from climate change:
-
Rising sea levels are eroding coastlines and swallowing up land.
-
Coral reefs are dying, affecting tourism and fishing industries.
-
Storms are becoming more violent and frequent.
For these countries, climate change isn’t a distant threat. It’s a daily crisis. With limited political or economic leverage, they turned to international law as their last resort.
Climate Justice, At Last?
For years, developing nations have argued that wealthy industrialized countries, particularly the United States, China, Russia, and members of the European Union, should take greater responsibility for the damage caused by their historic emissions.
But despite climate talks, promises of financial aid, and pledges made at COP summits, very little has translated into action. The legal route was always considered “unrealistic”—until now.
This ruling marks a seismic shift. It gives vulnerable nations a powerful tool: the right to demand accountability.
It’s a move from diplomacy to litigation, from vague promises to enforceable obligations. It also aligns with other recent global developments in climate law:
-
In March 2023, the UN General Assembly requested an advisory opinion from the International Court of Justice (ICJ) on countries' obligations regarding climate change.
-
The European Court of Human Rights (ECHR) has also begun hearing climate-related human rights cases.
Together, these legal developments suggest a new era: climate justice through international law.
Why This Ruling Matters for Every Country
The decision doesn’t just affect island nations. It impacts every country with a coastline—which is most of the world. That includes:
-
The United States
-
China
-
India
-
Brazil
-
Indonesia
-
Japan
-
The UK
-
Australia
-
Much of Europe and Africa
If greenhouse gas emissions are legally considered a form of marine pollution, then any country whose emissions harm another’s marine ecosystem could face legal consequences.
For example:
-
If rising CO₂ levels from the U.S. result in coral bleaching in the Pacific Islands, those islands could sue.
-
If Arctic warming caused by European emissions leads to fisheries loss in Inuit regions, there’s now a legal argument.
This legal mechanism forces wealthier, polluting nations to weigh their actions more seriously, not just morally, but legally and financially.
The Road Ahead: Will Countries Actually Sue?
So what happens now? Will countries actually begin filing lawsuits against each other?
Possibly—but it’s complicated.
Lawsuits between states in international courts are rare and politically sensitive. They often require years of preparation, and the outcomes aren’t guaranteed.
However, the advisory opinion is expected to:
-
Strengthen future legal cases brought before the International Court of Justice (ICJ) or Permanent Court of Arbitration (PCA).
-
Pressure nations to adopt stricter climate policies, knowing they could be held accountable.
-
Bolster negotiations over climate finance and loss-and-damage funds.
It may not lead to an immediate flurry of lawsuits, but it will definitely reshape the legal and political dynamics around climate change.
Potential Legal Precedents
Here are a few potential scenarios where this ruling could set precedent:
-
Small Island States vs. Industrial Nations: If Tuvalu or Antigua and Barbuda were to sue Australia, the U.S., or the EU, they now have the legal standing to do so.
-
Fisheries & Economic Loss Claims: Countries with damaged fisheries due to ocean acidification (such as Peru or Indonesia) could argue for compensation.
-
Loss of Land & Relocation Costs: Nations that must relocate communities due to sea level rise (e.g., Kiribati or the Maldives) could claim reparations for the costs.
Legal scholars say this could even lead to reparations-style lawsuits, where countries seek compensation for historical pollution.
What Critics Are Saying
Of course, not everyone is celebrating.
Some legal analysts argue that the ruling, being advisory in nature, lacks enforcement teeth. Others warn it could create geopolitical tension, especially if small states take on superpowers in court.
Polluting nations may also resist acknowledging the decision, particularly those outside the UNCLOS framework (like the United States, which has signed but not ratified UNCLOS).
There are also concerns about fragmentation in international law. Multiple climate cases in various courts could create inconsistent rulings.
Still, the symbolic and strategic value of this decision remains huge. It changes the conversation from “Should countries be responsible?” to “How much are they responsible for—and what should they pay?”
A Global Call for Climate Responsibility
Beyond the legal technicalities, the ruling is a moral wake-up call. It validates what climate activists and vulnerable nations have been saying for decades: Climate change isn’t just a tragedy. It’s a harm. And harms have consequences.
The Earth’s oceans are warming, rising, and acidifying. Communities are being displaced. Ecosystems are collapsing. These are not abstract events—they are the direct results of political and industrial choices made over decades.
For the first time in history, the global legal system is catching up.
The Role of Youth and Civil Society
This legal movement wouldn’t be happening without the relentless push from climate youth, indigenous activists, and NGOs. Groups like Greenpeace, Client Earth, and Earth justice have long been pushing for international legal accountability.
Young climate activists like Vanessa Na k ate, Greta Thunberg, and Fridays for Future have turned the world’s attention to the injustices faced by those least responsible for climate change.
This ruling, while led by states, is the fruit of grassroots labor—of protests, petitions, and powerful advocacy.
What Happens Next?
The next major step will likely be the International Court of Justice (ICJ) issuing its own advisory opinion on state obligations for climate change. That opinion is expected in late 2025 or early 2026 and could further cement the legal responsibilities of nations.
Meanwhile:
-
Countries are likely to reassess their climate policies to avoid potential liability.
-
Legal experts and climate lawyers are preparing cases in anticipation of future litigation.
-
UN negotiations over loss and damage funds will take on new urgency.
This is a pivot point. Climate change has moved from protest signs to courtrooms—and it’s not going back.
Final Thoughts: A Watershed Moment
This ruling by ITLOS is more than just a legal interpretation—it’s a statement of principle: that no country has the right to pollute with impunity.
It reflects a deepening understanding that the climate crisis is also a justice crisis. One where those who have done the least to cause the problem suffer the most.
In giving nations a legal path to seek redress, this decision doesn’t just open courtroom doors—it opens the door to fairness, to accountability, and to hope.
The world is watching. And now, so is the law.
References: