The International Court of Justice’s advisory opinion on climate change marks a historic advance in recognising that climate change is a human rights issue and establishing the obligations of states to prevent climate harm. It’s a civil society victory, since this breakthrough began when young Pacific Island climate activists urged their governments to go to the court. It comes in the wake of a similar ruling from the Inter-American Court of Human Rights, and both will give fresh impetus to civil society’s efforts to use litigation to hold states and corporations to account for climate failings. The age of climate impunity may be coming to an end.

What began with 27 law students in a Pacific Island classroom has led to the world’s highest court delivering an unprecedented ruling that ought to be a game-changer for global climate action.

On 23 July, the International Court of Justice (ICJ), the United Nations’ (UN) principal court, delivered its Advisory Opinion on states’ climate obligations. It came in response to a March 2023 UN General Assembly resolution, which asked the court to clarify under international law what states should do to respond to climate change and what the legal consequences are when they fail to act.

The court’s 15 judges adopted the advisory opinion unanimously – only the fifth time they’ve done so in the court’s almost 80-year history. The case attracted the ICJ’s highest-ever level of participation, with states and international bodies submitting 91 written statements and 62 written comments, and 96 states and 11 international organisations taking part in public hearings held last December.

The outcome of that process is a decision that couldn’t be clearer. The court’s ruling determines that states have a legal duty to prevent significant environmental harm. This requires them to mitigate greenhouse gas emissions and adapt to climate change. Global north countries, as historically the biggest emitters, bear special responsibility to lead emissions cuts. The court backed the Paris Agreement’s requirement that states must make progressively more ambitious climate plans under the Paris Agreement to limit the global temperature rise to 1.5 degrees above preindustrial levels. States also have a duty to cooperate with each other to achieve climate goals.

Crucially, the court rejected arguments that individual states can’t be held responsible for climate harm on the basis that their specific contribution can’t be calculated. Any breach of climate obligations constitutes an intentionally wrongful act, creating a duty to provide compensation or other forms of reparations. This includes failure to take due diligence to prevent climate harm and applies to fossil fuel production and consumption, exploration licences, fossil fuel subsidies and failures to adequately regulate the private sector.

The court rooted its opinion in established and binding international law, going far beyond climate agreements. In doing so, it rebuffed the arguments of high-emitting states, including China, Saudi Arabia, the UK and those in the European Union, which argued the court should consider only climate-related treaties in determining states’ obligations. The court’s decision makes crystal clear that climate change is a human rights issue, as the right to a clean, healthy and sustainable environment is essential for access to all other human rights.

The court’s recognition of fossil fuel emissions as a key driver of the climate crisis acknowledges a truth petrostates and the powerful fossil fuel lobby have long tried to evade: it took the 28th annual climate summit for states to collectively acknowledge the need to cut fossil fuel emissions, and subsequent meetings have gone no further. The taboo should now be well and truly broken.

Civil society’s triumph

The case was brought by a group of Pacific Island states, headed by the government of Vanuatu, which has become a global leader in the quest for climate justice. The Pacific Islands are on the sharp end of climate injustice: they’ve done almost nothing to cause climate change, contributing a fraction of the emissions of global north nations, but are on the frontlines of impacts – which in the case of low-lying nations such as Tuvalu, means having to plan for catastrophic loss of territory due to sea-level rise.

The advisory opinion marks a victory for Pacific Island states on the global stage, but it’s a breakthrough that originated in civil society. In 2019, student groups from eight Pacific Island countries formed the Pacific Islands Students Fighting Climate Change network, with the express aim of convincing their governments to push for a UN resolution to request an ICJ opinion. They engaged with their governments to win buy-in, and the UN resolution went on to be backed by 132 states, a huge majority. They’ve proved how civil society can make real impacts, even when it aims high.

Another key ruling in the Americas

The ICJ’s decision is strikingly similar to that issued earlier in July by the Inter-American Court of Human Rights (IACtHR). Chile and Colombia requested an advisory opinion on the climate emergency and human rights in January 2023, and the process attracted the court’s highest-ever level of participation, with over 220 civil society groups making submissions. Like the ICJ’s decision, the conclusions are everything climate campaigners hoped for.

The IACtHR, like the ICJ, recognised that people have a right to a healthy and stable climate. This means states should take steps to prevent and adapt to climate change, provide reparations for damage and regulate companies responsible for climate harm. They must make more ambitious, binding and transparent plans under the Paris Agreement.

Reflecting the inclusive nature of the process that informed the decision, the court’s opinion also says states should involve particularly affected groups in their climate decision-making, such as women and Indigenous people. Many of civil society’s ideas are reflected in the ruling, such as the creation of specialised courts to hear climate cases and provision of judicial training on climate issues.

Voices from the frontline

Manuel Páez Ramírez is coordinator of the Espeletia Legal Clinic at the Externado University of Colombia.

 

The most revolutionary element is the recognition of the right to a healthy and stable climate as an autonomous right, which reinforces states’ obligation to protect the global climate system. Until now, many judges have questioned the legal force of climate commitments. This opinion changes the landscape by connecting pronouncements by the UN, the European system and national courts with the rights protected by the American Convention on Human Rights. It establishes specific duties, the violation of which may result in international liability.

The court defined ‘climate damage’ as any transboundary impact on the climate system that a state has contributed to. To prevent this, it ordered the reduction of greenhouse gas emissions, the design of mitigation strategies and the strict regulation of companies that degrade the environment.

A crucial idea is that states must act with ‘enhanced due diligence’ when preventing and identifying risks and taking preventive measures, even in the worst-case scenarios. They must also constantly monitor their policies to avoid creating new vulnerabilities.

 

This is an edited extract of our conversation with Manuel. Read the full interview here.

International momentum builds

Civil society advocacy has built momentum across international arenas in recent years. In 2024, the International Tribunal for the Law of the Sea issued its first climate-related ruling, stating that greenhouse gases absorbed by oceans count as marine pollution. This broke new ground by requiring states to control and reduce emissions as part of their efforts to curb pollution. The ruling set an important precedent, reflected further in the ICJ and IACtHR decisions, by establishing that states have climate obligations beyond the Paris Agreement.

2024 also saw the European Union adopt its Corporate Sustainability Due Diligence Directive, which aims to protect human rights and the environment while responding to climate change, requiring large companies to align with the Paris Agreement. Civil society played a major role in campaigning for the directive, which opens up the prospect of civil society groups bringing claims against companies that fail to comply.

More good news could come before the year’s end, with the African Commission on Human and Peoples’ Rights expected to issue an advisory opinion on states’ climate obligations. Unlike the ICJ and IACtHR, civil society as well as states can request advisory opinions from the African Commission, and this process was initiated by the Pan African Lawyers Union, backed by climate, environmental and youth organisations. A positive ruling would add further momentum to civil society’s efforts to hold states and corporations to account.

Climate litigation a growing field

While the ICJ and IACtHR advisory opinions aren’t legally binding, they carry weight. Their reasoning influences other legal processes, which matters because civil society is increasingly taking to the courts to hold governments and companies accountable for climate impacts. Almost 3,000 lawsuits have been documented since climate litigation began, encompassing close to 60 countries.

Civil society has won some landmark victories. In April 2024, KlimaSeniorinnen Schweiz, a group of older Swiss women, won its case at the European Court of Human Rights, setting a precedent for 46 European states. It successfully argued that the women’s rights to family life and privacy were being violated because the government wasn’t doing enough to cut greenhouse gas emissions.

Climate litigation has expanded beyond its historical focus in Europe and North America, with civil society increasingly taking action and winning victories elsewhere. Last August, South Korea’s Constitutional Court ruled that the lack of emissions cuts targets violates the constitutional rights of young people and ordered the government to change the law. That same year in a case brought by a conservationist, India’s Supreme Court ruled that people have a fundamental right to be free from the harmful impacts of climate change. Legal actions continue: New Zealand civil society groups have recently filed a challenge against their government’s revised climate plans, which place less emphasis on cutting emissions in favour of discredited offset schemes.

The IACtHR’s decision and, it’s to be hoped, the one to come from the African Commission, could trigger a fresh wave of climate litigation in Africa and the Americas. The ICJ’s ruling in particular is sure to provide the backbone for many legal actions, and national and other international courts are likely to find arguments based in the ICJ’s opinion compelling. It will give an important boost to climate litigation efforts, at a time when corporations and climate denial groups are also bringing lawsuits to try to stifle civil society.

The ICJ’s decision offers fresh scope, for example, to sue states that produce unambitious national action plans as part of the current round of updates in preparation for the next climate summit, COP30. It opens an avenue for civil society to litigate for breaches of other human rights treaties beyond those on climate.

States on the frontlines of climate impacts could now take legal action at the ICJ against high-emitting states, including as a result of their failure to regulate fossil fuel companies. With wealthy states dragging their heels on providing the financing needed to transition to low-emission economies, adapt to climate change and compensate for the loss and damage caused, the ICJ’s recognition that states that breach obligations should pay reparations offers hope of enforcing the polluter pays principle.

The ICJ and IACtHR have established that climate is a human rights issue, and failures to act are attacks on rights. The decisions should supercharge a new era of litigation, promising an end to climate impunity. Civil society, having played a major role in these decisions being reached, will be sure to seize the opportunity.

OUR CALLS FOR ACTION

  • International and national courts should take strong account of the International Court of Justice’s Advisory Opinion in determining climate-related lawsuits.
  • International civil society should support human rights climate litigation in global south countries, including by sharing capacities and mobilising pro bono support.
  • The African Commission on Human and Peoples’ Rights should take recent climate rulings into consideration when framing its decision on states’ climate obligations.

For interviews or more information, please contact research@civicus.org

Cover photo by Marta Fiorin/Reuters via Gallo Images