Preparation underway for influx of legal actions over climate change, spurred by International Court of Justice's decision
The International Court of Justice (ICJ) has issued an advisory opinion on July 23, 2025, stating that a clean, healthy, and sustainable environment is a basic human right. This landmark ruling carries significant legal implications for both investor-state arbitration and domestic lawsuits.
The request for the advisory opinion stemmed from a UN General Assembly resolution adopted in March 2023, at the request of Vanuatu and supported by more than 130 nations. The ICJ's document, spanning over 500 pages, emphasizes the urgency of the climate crisis.
For investor-state arbitration, the advisory opinion reinforces states' obligations to protect the environment and reduce greenhouse gas emissions. States must exercise due diligence and apply the precautionary principle to environmental harm, especially climate-related damages, under international law. If states fail to meet these obligations, they may incur legal responsibility to cease harmful conduct, guarantee non-repetition, and provide reparations—even in disputes involving investors.
In domestic lawsuits, the ICJ advisory opinion strengthens the legal basis for climate and environmental claims. It affirms that the right to a healthy environment is essential for the enjoyment of fundamental human rights such as the right to life, health, and adequate living standards. This recognition can empower courts in various countries to interpret national constitutions and legislation in a manner consistent with international law, potentially facilitating claims against governments or private actors for failing to protect the environment or mitigate climate change.
The ICJ's ruling is likely to influence a range of legal claims, including inter-state petitions, domestic lawsuits, and investment arbitration. Greenpeace legal counsel Danilo Garrido wrote that the ICJ's advisory opinion marks a turning point for climate justice.
The ICJ's ruling also reinforces the principle that wealthier nations carrying greater emissions and historical responsibility have more demanding duties, relying on the "common but differentiated responsibilities" doctrine from the Paris Agreement. The ICJ observed that a state's disappearance due to rising seas does not extinguish its legal existence, and that displaced people should not be denied refuge when their lives are under threat.
Climate campaigners and Pacific islanders welcomed the ICJ's advisory opinion as a breakthrough. Ralph Regenvanu, Vanuatu's climate minister, described the ruling as a "landmark moment." Flora Vanu, a women's community leader in Vanuatu, urged immediate action.
The ICJ's advisory opinion is not legally binding but carries substantial moral and legal weight. The ruling establishes the right to a healthy environment as a binding international legal norm linked to existing human rights obligations. It imposes state duties to prevent environmental harm and climate change based on due diligence standards, with legal consequences for breaches, including liability and reparations.
This convergence of climate law and human rights law through the ICJ’s ruling marks a landmark shift in global environmental jurisprudence, likely affecting litigation and arbitration strategies regarding climate responsibility and environmental protection. The ICJ's advisory opinion provides a robust legal basis for future judicial action, including investor-state arbitration. The ICJ confirmed that failing to limit greenhouse gas emissions may amount to an "internationally wrongful act."
The ICJ's ruling also has implications beyond the legal sphere. In the European Court of Human Rights case Verein KlimaSeniorinnen Schweiz and Others v Switzerland, Article 8 of the European Convention on Human Rights was found to include a right to effective protection by the state from the serious adverse effects of climate change. The ICJ's advisory opinion goes some way to reframe the global discourse on climate change, suggesting that failure to act could carry legal consequences.
[1] Source 1 [2] Source 2 [3] Source 3 [4] Source 4
The ICJ's advisory opinion, as stated on July 23, 2025, has significant implications for both investor-state arbitration (Source 2) and domestic lawsuits (Source 3), setting a new standard for environmental protection under the guise of the right to a healthy environment, a fundamental human right. This development in environmental-science-related legal proceedings may influences general-news discussions about climate-change, politics, and international human rights.
The ICJ's ruling has also been interpreted as a turning point (Source 4) for climate justice, as it reinforces states' obligations to prevent environmental harm, reduce greenhouse gas emissions, and address the urgency of the climate crisis (Source 1), thus garnering attention from various sectors, including climate campaigners, Pacific islanders, and the broader international community.
