by Daniel Brouse
July 23, 2025
The International Court of Justice (ICJ), the UN's highest judicial body, issued a landmark opinion today (July 23, 2025), declaring that states have clear legal obligations under international law to prevent and address climate harm. Requested by Vanuatu and supported by a coalition of climate-vulnerable nations, this opinion will help reshape the global legal landscape on climate accountability and justice.
The ICJ clarified that countries are legally required to take meaningful action to mitigate and adapt to climate change, emphasizing that failure to do so violates existing international commitments. The opinion underscores that states cannot ignore the growing body of climate science and must act in line with principles of prevention and precaution to avoid transboundary harm.
While advisory opinions are non-binding, the ICJ's analysis could form the backbone of future efforts by climate-impacted nations to seek compensation from major polluters for climate-related loss and damage. The ruling provides a legal foundation that may bolster claims for reparations and reinforce the "polluter pays" principle in international law.
The ICJ opinion explicitly connects environmental degradation with the erosion of fundamental human rights, including the rights to life, health, food, water, and cultural integrity. By framing climate harm as a human rights issue, the ruling strengthens the legal arguments of vulnerable communities seeking justice for the disproportionate impacts of climate change.
Although the ICJ's advisory opinions do not compel direct enforcement, they carry significant legal weight and are often used by courts, policymakers, and international bodies as authoritative interpretations of international law. This opinion is expected to guide domestic and international courts in climate litigation, shape policy decisions, and influence future negotiations under the UN climate framework.
The ICJ's decision follows a wave of significant international rulings that are collectively shifting the climate crisis from the realm of policy debates into enforceable legal obligations:
In May 2024, the International Tribunal for the Law of the Sea (ITLOS) clarified that states must reduce greenhouse gas emissions under the Law of the Sea, framing ocean protection as inseparable from climate action.
Earlier this month, the Inter-American Court of Human Rights (IACHR) ruled that states have a duty to prevent and remedy climate crisis-induced loss and damage, including regulating corporate actors and ensuring access to justice for affected communities.
These decisions reflect a growing global recognition that climate inaction is not only environmentally negligent but also a breach of legal responsibilities owed to current and future generations.
Global Legal and Policy Impact: Governments, legal experts, and civil society organizations are expected to study the ICJ's opinion closely to clarify accountability frameworks and liability mechanisms for climate harm.
Acceleration of Climate Litigation: The ruling may inspire new lawsuits worldwide seeking damages or stronger emissions reductions, further pressuring states and corporations to take meaningful climate action.
The Ecocide Debate: Discussions at the International Criminal Court (ICC) continue regarding the potential recognition of "ecocide" as an international crime against humanity, though expanding the Rome Statute remains a politically and legally challenging process.
What will drive the change we need? Litigation over loss and damage against oil companies and governments will help fundamentally reshape global economics.
Just as tobacco litigation changed the smoking industry, the oil industry now faces a similar reckoning. Consumers and communities, misled for decades about the dangers of burning fossil fuels, are filing lawsuits to hold oil companies accountable for climate damage. As with cigarettes, this will make fossil fuels harder to buy and insure, driving a shift away from dependence on oil.
At the same time, young people around the world are suing their governments for failing to protect their basic human rights. In Held v. Montana, a district court ruled that Montana's Environmental Policy Act--which prohibited consideration of climate impacts in energy decisions--violated the state constitution's guarantee of "a clean and healthful environment." This is part of a rising wave of youth-led legal actions demanding that governments take responsibility for the climate crisis.
These court rulings represent a pivotal moment in the global climate effort. By establishing that states and corporations have binding legal obligations to prevent climate harm and protect human rights, these decisions are transforming the climate emergency from a moral plea into a legal imperative. They are creating enforceable pathways for accountability, justice, and reparations for those most vulnerable to the escalating impacts of climate change.