The International Court of Justice (ICJ) issued a landmark advisory opinion in July 2025, ruling that government actions causing climate change are illegal. This ruling demands states be held accountable for emissions. Though advisory and non-binding, the opinion carries legal and moral weight. It aims to influence global climate negotiations, especially the upcoming COP30 summit in Belem, Brazil, and boost the position of vulnerable nations facing severe climate impacts.
Background and Context
The ICJ, the UN’s principal judicial organ based in The Hague, was requested by the UN Secretary-General in April 2023 to provide an advisory opinion on states’ obligations under international law to protect the climate system. This request followed pressure from Pacific island nations, youth groups, indigenous peoples, and civil society demanding stronger legal accountability for climate harm.
Key Findings of the ICJ Advisory Opinion
The court unanimously declared that states have binding obligations to mitigate greenhouse gas emissions and adapt to climate change. It reaffirmed that developed countries, listed in Annex I of the UNFCCC, bear greater responsibility to lead emission reductions. The ruling brought into light the duty of states to cooperate in achieving the Convention’s goals and to respect international human rights law by protecting the environment.
Legal Responsibilities and Consequences
The ICJ stated that breaches of climate obligations constitute internationally wrongful acts. States responsible for such acts must cease harmful activities, provide guarantees against recurrence, and offer full reparations where direct harm is proven. This aligns with the loss and damage framework in UN climate negotiations, which seeks compensation for vulnerable countries affected by climate impacts.
Impact on Global Climate Policy
Though advisory, the ruling is expected to strengthen climate litigation worldwide and add legal clarity to international climate diplomacy. It revives the issue of historical responsibility of developed nations, which had been downplayed in the Paris Agreement. The opinion pressures countries like the United States, which remains party to the UNFCCC despite withdrawing from the Paris Agreement under previous administrations.
Significance for Vulnerable Countries
The opinion is a powerful tool for climate-vulnerable nations, including many in South Asia and the Pacific. It supports their demands for stronger global action and compensation for climate damages. Civil society leaders and climate experts describe the ruling as a game changer that will reshape negotiations at COP30 and beyond.
Broader Environmental Obligations
The ICJ also reminded states of their duties under other environmental treaties such as the Vienna Convention, Montreal Protocol, Convention on Biological Diversity, and the UN Convention to Combat Desertification. This holistic approach emphasises the interconnectedness of climate change with biodiversity loss and land degradation.
Role of Youth and Civil Society
The advisory opinion reflects the growing influence of youth and civil society in pushing climate issues to the highest legal forums. It signals a shift towards recognising climate change as a fundamental human rights and justice issue, not just an environmental challenge.
Questions for UPSC:
- Critically analyse the role of the International Court of Justice in addressing global environmental issues with suitable examples.
- Explain the concept of state responsibility under international law and its relevance to climate change mitigation and adaptation.
- With suitable examples, comment on the significance of the principle of common but differentiated responsibilities in international climate agreements.
- What are the challenges faced by vulnerable countries in international climate negotiations? How can legal instruments strengthen their position?
