After months of anticipation, the International Court of Justice (ICJ) has delivered an advisory opinion on climate change – confirming the obligation of countries to act decisively in response to the environmental consequences or they would commit “an internationally wrongful act”. So, what’s next?
The ICJ case was championed and driven by Pacific Island countries. The advisory opinion opens the door for vulnerable states to seek compensation from those dodging climate action. Critically, the court’s finding extends state responsibility for emissions beyond the burning of fossil fuels to the subsidisation of the industries involved, as well as extraction. This result also steps up pressure on polluters, dismissing the need to prove a full causal link between action and damage in cases where existing scientific evidence is deemed sufficient.
The opinion marks a third win for climate activists under international law. An earlier advisory opinion of the International Tribunal of the Law of the Sea (ITLOS) set out state responsibility for climate emissions that adversely impact marine environments. The Inter American Court of Human Rights also affirmed that climate action amounts to a human rights obligation. Another case is underway in the African Court for Human Rights also relating to climate justice.
ICJ advisory opinions are not enforceable or legally binding, but still hold significant weight. The opinion provides a strong legal foothold for existing and future cases, increasing pressure on governments and private polluters to reduce their greenhouse gas emissions. Some cases against governments that advance state obligations for climate action have already succeeded prior to the ICJ’s advice, including those against Germany (Neubauer, et al vs Germany), Ireland (Friends of the Irish Environment vs Ireland),the Netherlands (Urgenda Foundation vs State of the Netherlands) and Switzerland (Verein Klimaseniorinnen vs Switzerland). The legal tides are turning.
Developing countries will use the international and national court findings as leverage to push for ambitious commitments.
The annual report on climate litigation by the London School of Economics shows staggering trends. In 2024, at least 226 new climate cases were filed, bringing the total number of cases across the globe to 2,967 across nearly 60 countries. Court lists in the United States are busiest with climate-related cases, with Australia ranking second. Around 80% of these challenge the adequacy of governments’ commitments to reduce emissions or decisions to allow mega fossil fuel projects.
Together these legal precedents and the ICJ opinion put private and state-owned fossil fuel producing companies on notice. Around 20% of climate cases filed in 2024 targeted companies or their directors and officers. Prominent past examples include Milieudefensie et al vs Royal Dutch Shell plc. and Lliuya vs RWE, a major German coal-producing company in Peru. These cases, and others like them, face significant legal hurdles to provide sufficient evidence of causal links to specific damage done. The ICJ’s opinion makes clearing those hurdles easier, stating that only a reasonable causal link needs to be proven. Even so, progress will be slow.
Under the United Nations Framework Convention on Climate Change, countries are expected to make further and more ambitious emission reduction commitments via nationally determined contributions. Increased commitments are due in September in the lead up to the annual climate summit, with COP30 to be held in Brazil. To date, no major polluter has submitted a pledge that would fairly match their global emissions contributions, which are pushing global climate increases above 1.5 degrees Celsius and closer to climate catastrophe. The ICJ opinion may provide a greater incentive to increase efforts.
Now that climate advocates have additional legal backing, the global commitment to transition away from fossil fuels made two years ago in the COP28 climate negotiations will be under sharp scrutiny. Saudi Arabia tried to reverse this progress the following year at COP29, with a delaying tactic seeing progress towards a fossil fuel-free world put off to this year’s talks in November. Developing countries will use the international and national court findings as leverage to push for ambitious commitments. COP30 in November will provide the first real test for the ICJ’s advisory opinion, revealing whether it will drive a new approach or simply fuel more legal wrangling.
Regardless, the ICJ’s advisory opinion marks a significant legal win. Pacific Island countries are fighting on. Vanuatu, Fiji and Samoa have submitted a resolution to the Rome Statute – the International Criminal Court – for a new crime of “ecocide” to be created in recognition of the irreversible damage to ecosystems from climate change.
One day, the world might look back and realise that the smallest countries in the world who contributed the least to climate change did the most to prevent it.
