Sea-level rise and the ICJ climate ruling: Understanding risks, planning action

On 23 July 2025, the International Court of Justice (ICJ), also known as the World Court, issued its first advisory opinion on climate change, “Obligations of States in respect of climate change”, marking a historic shift in international legal responsibilities. It affirmed what millions have long demanded: climate change threatens our very survival, and high-emitting states can and must be held accountable.

This ruling is more than a legal milestone. It’s a powerful tool for global advocacy, one that people, communities, and policymakers can use to demand stronger, science-based climate action from their governments.

What did the World Court (ICJ) rule on climate change?

• Climate change is classified as an “urgent and existential threat, and States have treaty-based and customary international law obligations to prevent significant environmental harm.
• The court affirmed that the right to a clean, healthy, and sustainable environment is a fundamental human right, critical for the enjoyment of other human rights.
• States may be held responsible for inaction, including failing to regulate emissions from the private sector (such as fossil fuel companies), with potential consequences including cessation, non-repetition, and full reparations if causation is established.
• Small island states—and by extension any climate-vulnerable region—are recognised as having distinct legal claims due to their heightened vulnerability and potential loss of statehood under sea-level rise.

The ruling gained remarkable legitimacy, with participation from 96 States and 11 international organisations during public hearings, making it the largest case in ICJ history, and was adopted unanimously by the 15 judges.

CoCliCo’s role: Supporting adaptation to the risks underlined by the ICJ

While the ICJ’s advisory opinion focuses on states’ legal obligations to reduce greenhouse gas emissions and prevent significant environmental harm, sea-level rise is one of the clearest and most impactful consequences of climate inaction.

This is where CoCliCo comes in.

Translating urgency into coastal risk understanding

CoCliCo reinforces the ICJ’s core message, that climate change is an urgent and existential threat, by offering a practical lens into what this threat means at the coastal level.

• Our platform helps you explore how rising seas will affect European coastlines, both today and under future climate scenarios.
• By making coastal flood risk data accessible, CoCliCo supports preparedness and planning, turning long-term global obligations into tangible local insights.

Helping stakeholders understand and take action on coastal risk

Whether you’re a planner, policymaker, researcher, or community advocate, CoCliCo enables you to:

• Visualise coastal risk under different climate and socio-economic scenarios, readily available on the web platform.
• Assess adaptation options like coastal protection, urban development limits, or managed retreat.
• Use user-informed analysis, called “user stories”, to understand how sea-level rise could unfold—and how adaptation strategies can be evaluated.
• Dive deeper into local analysis using our risk and mapping models and data, directly from the Workbench.

Our platform, workbench, and data complement legal and policy efforts by making the physical implications of climate change—particularly sea-level rise—clear and actionable.

Access the platform here: https://platform.coclicoservices.eu/

Use the handbook to learn more about using the platform, performing further analysis through our Workbench, or using our data directly: https://www.openearth.nl/coclico-workbench/

Final thoughts

The ICJ has confirmed that preventing environmental harm is a legal obligation. At CoCliCo, we see this as a call not only for emissions reduction, but also for proactive adaptation to the impacts that are already underway, including sea-level rise.

Our platform is one step in helping you meet that challenge by making coastal risk visible, understandable, and planable.

Explore CoCliCo and see how data-driven adaptation planning can complement global climate responsibilities.