The United Nations’ highest court, the International Court of Justice (ICJ), issued a unanimous advisory opinion last week, declaring that greenhouse-gas emissions may constitute an “internationally wrongful act under existing international law”. Saint Lucia was one of the 132 countries backing the Vanuatu‑led initiative, lending its voice to a groundbreaking appeal for climate justice.
Why does the opinion matter? The ICJ’s ruling affirms that climate change poses an urgent and existential threat, and that governments which continue to support fossil fuel production, licensing, or subsidies may be in violation of international law. It opens the door for states to be held legally responsible for climate-related harms, including potential obligations to provide financial or ecological reparations to affected countries and communities. Perhaps most significantly, the court reinforced that access to a clean and healthy environment is a fundamental human right, placing clear legal duties on states to regulate both public and private actors through rigorous due-diligence measures.
The landmark opinion has drawn reactions internationally and even locally. “I was quite elated… the recognition by the court that small island developing states are vulnerable and that they must be treated separately is a very important one. It also recognised that there’s a duty to prevent significant environmental harm,” explained Dr James Fletcher, who serves as the CARICOM Climate Envoy.
For island nations such as Saint Lucia, already grappling with sea-level rise, extreme storms and coastal erosion, the ICJ’s opinion could herald new legal tools for climate reparations and greater diplomatic leverage on the world stage.
“It is establishing new jurisprudence on climate. So we now have a basis that if legal action is taken in a country, there is an advisory opinion that can now form the foundation of how that legal action can be adjudicated,” Fletcher said.
Now that the International Court of Justice (ICJ) has issued its advisory opinion, the next step is for it to be formally returned to the United Nations General Assembly (UNGA), which initially requested it. While the opinion is not legally binding, it still carries significant legal and political weight. The UNGA may hold discussions or adopt resolutions to support the ICJ’s findings. These actions could encourage member states to adjust their climate policies.
The opinion is also expected to influence international climate negotiations, including the upcoming COP30 in Brazil. It gives vulnerable nations like Saint Lucia a stronger position when calling for tougher climate commitments, clearer rules on loss and damage, and greater accountability from major polluters.
In addition, the ICJ’s ruling can be used in national courts and regional legal systems. It may serve as a reference in climate-related lawsuits or be used to support policy reforms. While countries are not required to follow the opinion, it increases pressure on governments and could lead to voluntary legal and policy changes.
What makes Fletcher a climate expert?