– Source:The International Court of Justice, the world’s highest court, handed down an advisory opinion on 23 July 2025 stating that climate change “imperils all forms of life”. This followed a case brought by Vanuatu, a tiny South Pacific island nation threatened by rising sea levels, supported by 131 other countries – the biggest case the court had ever heard. The opinion sets out what all governments need to do to limit greenhouse gas emissions and prevent further global warming. Climate law specialist Zunaida Moosa Wadiwala explains how the advisory opinion sets a powerful precedent for global climate accountability.
What did the International Court of Justice find?
The court’s advisory opinion confirmed that states have binding obligations under international law to protect the climate from human-caused climate change.
Judge Dire Tladi, also the first ever South African judge at the International Court of Justice, described this as one of the most consequential matters ever brought before the court. He emphasised that climate change is an existential crisis that potentially threatens the future of humanity.
Unanimously, the court issued the opinion that States have binding legal obligations to prevent further global warming. These obligations are grounded in climate treaties, international human rights law and customary international law. They are also grounded in global agreements to protect specific parts of the environment (like the Ozone Convention, Biodiversity Convention, Desertification Convention, and the United Nations law of the sea).
The advisory opinion said governments must take appropriate measures to prevent environmental harm. This means that states are obliged to implement programmes to adapt their countries to climate change. They also need to show that they are reducing greenhouse gas emissions.
The court also stated that breaching these obligations is an internationally wrongful act. As such, the government responsible will have to stop the harmful conduct. They’ll also need to guarantee that they’ll never repeat the wrongful act and make full reparation to whoever was affected.
The advisory opinion is poised to reshape international climate litigation and domestic policy.
Is this a victory for African nations who provided evidence?
Yes. Kenya, Ghana, Madagascar, South Africa, Cameroon, Sierra Leone, Mauritius, Burkina Faso, and Egypt made submissions about climate change damage. The Court accepted their arguments that developing countries have contributed minimally to greenhouse gas emissions globally, yet suffer the effects of climate change more than developed nations.
The advisory opinion also highlighted that a clean, healthy and sustainable environment is necessary if people are to enjoy their rights to access to water, food and housing. These were key issues raised by African States.
The court also specifically responded to the arguments of African nations by affirming that developed countries must support developing States to adapt to climate change. Developed States are obliged to provide financial support, make new adaptation technologies available and assist vulnerable nations to build capacity to cope with global warming.
The Court endorsed a rights-based approach, particularly the rights to life, health and a clean, sustainable environment and said climate change obligations are erga omnes (a responsibility for all States). This also vindicates African nations longstanding calls for climate justice, legal clarity and recognition of the unequal burden they bear.
Will it help African countries sue for reparations for climate damage they didn’t cause?
Yes. African countries now have tools to pursue reparations for climate-related harm. They will need to establish causation between the wrongful act of one or more states and damage suffered. In other words, they will need to prove that the damage was factually and legally caused by a certain country or countries.
One challenge in enforcing this is that the International Court of Justice does not issue binding judgements in advisory opinions. So, to claim reparations, African states would need to initiate contentious proceedings in the court against high-emitting countries. The consent of the countries concerned, indicating their acceptance of the jurisdiction of the International Court of Justice is required.
Given the global and cumulative nature of emissions, causation and damages are complex. It could be difficult to prove that specific damages, such as floods, mudslides, drought and heatwaves, are caused by one or more specific countries.
Another option for affected countries is domestic or transnational climate litigation. This means that countries affected by climate-caused disasters could sue fossil fuel companies in foreign courts.
The International Court of Justice advisory opinion is strong backing for arguments based on the law of delict (tort). This is where a wrongful act causes damage for which the person harmed can claim compensation. The opinion also backs arguments that greenhouse gas emissions amount legally to nuisance (interference with the use and enjoyments of another’s property) and or unjust enrichment (when one person unfairly benefits at the expense of another).
What does this mean for African countries still exploring for – and using – fossil fuels?
The advisory opinion is very specific on how fossil fuels like gas, oil and coal must be approached. It says that if a State continues fossil fuel extraction, and fails to take appropriate climate action, it may be violating international law. Continuing to produce and consume fuels, giving out licences to mining companies to explore for fossil fuels and subsidising the fossil fuel industry may also violate international law.
Within the context of State responsibility, this has serious legal implications for the 48 African countries who are still involved in these fossil fuel activities.
The advisory opinion has placed these countries at a crossroads. They cannot advocate for climate justice abroad whilst expanding fossil fuels at home. A State could also be held responsible for not passing regulations to limit emissions caused by private companies under its jurisdiction.
This is a step forward. For example, in South African climate cases that have already been ruled on, they mainly relied on procedural, constitutional or climate risk-based legal strategies. In other words, they argued that communities had not been consulted properly before a coal mine licence was granted, or that the mine would interfere with the human right to water.
But now, fossil fuel activities themselves are restricted.
In South Africa, this is aligned with the Climate Change Act. This new law, passed in 2024, phases down and phases out human caused greenhouse gas emissions. It sets out how South Africa should transition to a low-carbon, climate-resilient economy.
Zunaida Moosa Wadiwala does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
By Zunaida Moosa Wadiwala, PhD candidate in international climate law and litigation and Sessional Lecturer- University of the Witwatersrand, University of the Witwatersrand
