International environmental law has been applied by international courts to resolve disputes between states, interpret treaties and customary law, establish environmental duties, and order remedies. This is HL-only content from subtopic HL.a Environmental law.
International courts generally act only when states have accepted their jurisdiction. They do not create a single global environmental code; instead, they apply international environmental law drawn from treaties, customary international law and general legal principles.
Courts frequently examine whether a state has exercised due diligence to prevent significant transboundary environmental harm. They may also enforce procedural duties, including conducting an environmental impact assessment, notifying affected states, sharing information and consulting before beginning a risky project.
| International case | Application of environmental law |
|---|---|
| Gabčíkovo-Nagymaros Project (Hungary/Slovakia), ICJ, 1997 | The International Court of Justice emphasized that economic development and environmental protection must be reconciled. It considered evolving environmental standards when assessing a disputed dam project. |
| Pulp Mills on the River Uruguay (Argentina v Uruguay), ICJ, 2010 | The Court found that Uruguay breached procedural duties to notify and consult Argentina. It also recognized that an environmental impact assessment is required where an industrial activity risks significant transboundary harm. |
| Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v Nicaragua), ICJ compensation judgment, 2018 | The Court ordered compensation for environmental damage, including the loss of ecosystem goods and services. This demonstrated that environmental harm can produce financial liability between states. |
Application remains limited by state consent, enforcement difficulties, scientific uncertainty and unequal access to legal expertise. Courts must also balance state sovereignty, development priorities, environmental protection and environmental justice.
Exam technique: For an “examine” or “evaluate” question, explain the legal mechanism, use at least one named case, assess both effectiveness and limitations, and finish with a supported judgment. Do not claim that international courts automatically enforce all environmental agreements.
