Historic ICJ advisory opinion: States must face legal consequences for climate inaction

A defining moment for global climate justice arrived on Wednesday in the Hague, the Netherlands, as the International Court of Justice (ICJ) delivered its landmark Advisory Opinion on the Obligations of States in respect of Climate Change. This marks the first time the court addresses the issue of climate change and the obligations of countries in tackling it.

The ICJ has determined that governments have a legal duty to protect the climate system and that nations primarily responsible for global warming through their emissions could now face legal repercussions for the harm inflicted upon other countries. 

The ruling, long anticipated by environmental advocates and international legal experts, redefines state obligations globally, clarifies international law, and could significantly reshape the landscape of climate accountability. 

For Africa, a continent disproportionately vulnerable to the devastating impacts of climate change — as South Africa has seen all too well in recent years with deadly flooding and drought events – this opinion offers an important legal foundation for demanding reparations and accelerating climate justice, empowering nations to hold historical polluters accountable, and driving more ambitious climate action.

These reparations can include restitution, compensation and satisfaction (such as public acknowledgement).

At its core, the ICJ was asked to address two fundamental questions: What states are legally required to do under international law to address climate change for both current and future generations, and what the legal consequences are when states fail to meet these obligations, causing significant climate harm. 

These questions cut to the heart of climate justice, delving into who bears responsibility for the climate crisis and what is owed to those who have contributed the least to global emissions, but are suffering the gravest impacts.

Although national courts have increasingly taken on climate-related cases, especially since the 2015 Paris Agreement, it’s still uncommon for international judicial bodies to engage with such matters. 

This marks the first occasion of the ICJ addressing the issue of climate change and the obligations of countries in tackling it.

The ICJ’s ruling follows a United Nations (UN) General Assembly resolution led by the Pacific island nation of Vanuatu, which requested the advisory opinion. 

In the ruling, it is stated unequivocally: “The environment is the foundation for human life, upon which the health and well-being of both present and future generations depend. The court thus considers that the protection of the environment is a precondition for the enjoyment of human rights.

“The court notes that the adverse effects of climate change, including, inter alia, the impact on the health and livelihoods of individuals, events such as sea level rise, drought, desertification and natural disasters may significantly impair … the right to life.”

Vishal Prasad, Director, Pacific Islands Students Fighting Climate Change, said this after the ruling: “Today the world’s smallest countries have made history. The ICJ’s decision brings us closer to a world where governments can no longer turn a blind eye to their legal responsibilities. It affirms a simple truth of climate justice: those who did the least to fuel this crisis deserve protection, reparations, and a future. This ruling is a lifeline for Pacific communities on the frontline.”

What is stated in the advisory opinion

The opinion was delivered by Judge Yuji Iwasawa after deliberation by the 15 judges of the ICJ. They unanimously declared that a nation's failure to protect the climate system could be considered an internationally wrongful act. 

They also determined that safeguarding the environment was a precondition for upholding human rights, and indicated that government backing of the fossil fuel industry might breach these principles.

In addressing these two complex questions, the Court primarily relied on the scientific consensus in the reports of the Intergovernmental Panel on Climate Change (IPCC), acknowledging them as the best available science on the causes, nature and consequences of climate change. 

The IPCC reports state that human-induced climate change, driven by anthropogenic greenhouse gas (GHG) emissions, has caused widespread adverse impacts and irreversible losses to nature and people. 

Between 3.3 billion to 3.6 billion people are highly vulnerable to climate change, experiencing increased extreme heat events, human mortality, morbidity and acute food and water insecurity. 

Most significantly, Iwasawa said: “Failure of a state to take appropriate action to protect the climate system from GHG emissions — including through fossil fuel production, fossil fuel consumption, the granting of fossil fuel exploration licences or the provision of fossil fuel subsidies — may constitute an internationally wrongful act which is attributable to that State.” 

What this means is that if a state does not take the necessary and appropriate steps to protect the global climate system from unliveable human-induced GHG emissions – including by regulating or ceasing activities such as fossil fuel production, consumption, licensing, or subsidising – then this failure to act under its international legal obligations (from treaties or customary law) can be considered a wrongful act for which that state can be held internationally responsible.

Danilo Garrido, who has worked at the ICJ and taught international law at the University of Oxford, now serves as legal counsel for Greenpeace, and told Daily Maverick that this was the “start of a new era of climate accountability”.

“This will open the door for new cases, and hopefully bring justice to those who, despite having contributed the least to climate change, are already suffering its most severe consequences. The message of the Court is clear: the production, consumption and granting of licenses and subsidies for fossil fuels could be breaches of international law. Polluters must stop emitting and must pay for the harms they have caused,” said Garrido.

How this could shape climate politics is that, according to Garrido, small island developing states will not approach climate change talks, such as the upcoming COP30, for charity or aid, but rather demand that high-emitting states simply meet their obligations for what they have caused. 

Read more: Landmark legal ICJ opinion expected on state climate obligations – and what SA wants

The Global Climate and Health Alliance also hailed this ruling as affirming that the climate crisis was a health crisis, and that failure to act was a failure to protect life.

Dr Jeni Miller, executive director at the Global Climate and Health Alliance, said:

“This ruling confirms that governments and corporations have a legal duty to prevent further harm, uphold the right to health, and safeguard future generations, from deadly heat and toxic air to disease and displacement. The Court’s message is clear — human health is not collateral damage. Health workers and advocates now have powerful legal backing to demand bold, science-based climate action rooted in justice, including a just transition away from fossil fuels, for health and the duty to protect life across all ages and borders.”

The significance of this advisory opinion cannot be overstated. While not directly legally binding in the same way as a contentious case, the ICJ advisory opinion carries immense moral authority and legal weight, clarifying the interpretation and application of international law. 

The ruling sets a historic precedent by reinforcing and expanding countries’ responsibilities under international law beyond those outlined in the Paris Agreement. 

It established key additional duties, such as the obligation for all States under climate change treaties and customary international law to prevent significant harm from GHG emissions, and to work together through international cooperation to achieve this.

Importantly, the Court ruled that States must hold businesses accountable for the environmental damage caused by their emissions, regardless of where the impacts occur. 

Other key findings are that the opinion distinguishes between mitigation (reducing emissions or enhancing sinks) and adaptation (adjusting to climate effects). Iwasawa noted that current adaptation measures are insufficient and that warming poses an increasing threat to human well-being and planetary health.

He also concluded that the existing climate change treaties do not generally exclude other rules of international law (lex specialis); rather, they form part of a broader set of compatible obligations.

Accountability vs avoidance

The public hearings that preceded Wednesday’s ruling revealed two polarised positions. On one side stood the historic GHG emitters. These were largely developed countries and petrostates such as Germany, the UK, Canada, China, India, the US, Russia, Saudi Arabia and Kuwait. 

These nations argued that existing climate treaties, such as the Paris Agreement, were the sole international law mechanisms governing climate change. They contended that international human rights law did not apply to climate obligations, and that the existing suite of international laws on state responsibility for harms caused would not be suitable in the context of climate change. 

This stance, critics argued, was driven by a desire to avoid legal obligations for reparations, preferring instead for any climate finance to be perceived as an act of generosity rather than a legal liability.

 On the other end were the climate-vulnerable states, those with the most to lose from climate change, despite having contributed the least to its cause.

These were small island developing states, facing existential threats from rising sea levels, and a large contingent of African nations. These included South Africa, Cameroon, Burkina Faso, Ghana, Namibia and Kenya, which all made compelling arguments for justice.

They asserted that customary international law and long-recognised rights, such as the right to self-determination, were indisputably affected by climate change. These nations argued for a legal duty for reparations for climate harms caused by high-emitting states, emphasising that existing climate treaties simply did not provide adequate remedies.

Africa’s unwavering stand for justice

Africa has emerged as a powerful voice in this global legal discourse. Perpetually marginalised in traditional climate negotiations, African states are now leveraging avenues like the ICJ to lay a foundation for future claims in response to the climate crisis. This marks the beginning of a firmer stance by the continent in the international arena.

Earlier this year, African civil society submitted a landmark petition to the Tanzania-based African Court on Human and Peoples’ Rights, seeking clarity on states’ obligations to protect climate-related human rights under the African Charter.

The petition noted the severe impact of climate change on vulnerable populations, despite Africa’s minimal historical GHG emissions, and called for strong protective measures against environmental harms.

Read more: States’ obligation to protect climate-related human rights heads to African Court on Human Rights

It is no surprise that many African states are taking such a strong position. The continent is disproportionately exposed to the devastating impacts of climate change, requiring substantial resources to respond to increasingly frequent and severe climate events. 

Africa’s history of colonial exploitation, coupled with crippling debt and barriers to global trade participation, places it at a severe disadvantage in its capacity to adapt and address climate impacts. 

A 2022 study by Christopher Callahan and Justin Mankin further showed how culpability for global warming rested primarily with a handful of major GHG emitters, whose enrichment had come at the expense of the world’s poorest populations.

According to this study, the top 10 most damaging countries are together responsible for more than 67% of losses and 70% of benefits. The US is the largest contributor, responsible for 16.5% of losses and 18% of benefits, followed by China with 15.8% of losses and 16.8% of benefits.

To date, the climate finance that has trickled down to affected states has been woefully insufficient, often taking the form of loans, leaving  African states trapped in a debilitating cycle of borrowing to rebuild after extreme weather.

This also leaves them unable to fully recover or prepare for worsening impacts.  

The African Union (AU) has been unequivocal in its demand that states responsible for climate system damage must cease their wrongful conduct and provide reparations. 

Several African nations, including Ghana, Kenya, Malawi and Sierra Leone have specifically called for debt cancellation as a form of reparation.

South Africa’s position

During the hearings, South Africa argued against a broader human rights approach to addressing climate change. This is notable given its unique circumstances as the highest GHG emitter within Africa, yet simultaneously a country grievously affected by the climate crisis and in dire need of resources for response and adaptation.

South Africa’s delegation, led by Ambassador Vusimuzi Madonsela, argued the country’s disproportionate vulnerability, citing rising temperatures, water scarcity, food insecurity, and severe flooding. 

Madonsela urged the court to consider the “complex phenomenon of climate change and the national circumstances of states with different capacities and responsibilities”. South Africa argued that “the historical responsibility for emissions [lies] at the doorstep of developed countries, hence the primary burden of responsibility for addressing it rests on their shoulders”.

He noted that developed countries, despite accepting this legal responsibility, had largely failed to honour it, adversely affecting the international community.

South Africa argued that although Africa contributed just 7% of global emissions, it remained one of the regions most vulnerable to the effects of climate change. Thus, many African countries have been allocating significant portions of their budgets to adaptation efforts, often without sufficient international support.

By contrast, developed nations are responsible for the bulk of historical emissions and have reaped economic benefits from this. South Africa said that these countries had a responsibility to take meaningful action and provide financial aid and technological support to developing nations.

International law experts weighed in that this advisory opinion, alongside similar recent rulings from the International Tribunal for the Law of the Sea and the Inter-American Court of Human Rights, which found that states and corporations had binding legal obligations to address the climate crisis as a human rights emergency, had the transformative potential to reshape climate governance, diplomacy, and litigation for decades to come, and to usher in a new era of climate accountability. 

In closing, Iwasawa said: “This is a concern of planetary proportions that imperils all forms of life … The court presents this opinion with a hope that its conclusions will allow the law to inform and guide social and political action to solve the ongoing climate crisis.” DM