“Dobbiamo proteggere l’oceano perché l’oceano ci protegge”. Brevi note sul parere del Tribunale internazionale per il diritto del mare in tema di cambiamenti climatici nel contesto delle decisioni giudiziarie in materia ambientale"

The Case Law on the obligations of States with regard to the environment and, in particular, combating climate change, is being enriched by new contributions at both the national and supranational levels. In addition to a series of decisions rendered in contentious cases, there is the Advisory Opinion No. 31 rendered on 21 May 2024 by the International Tribunal for the Law of the Sea (ITLOS) at the request of the ‘Commission of Small Island States on Climate Change and International Law’ (COSIS). This opinion recognised that greenhouse gas (GHG) emissions from human activities are a cause, and therefore a form, of marine pollution, and that States are therefore obliged to take measures to prevent, reduce and control such pollution. To summarise, these are the main points of the opinion: the reaffirmation by the Court of its competence in advisory matters; the need for a precautionary approach, based on current scientific knowledge; the extension by way of interpretation of the obligations of the United Nations Convention on the Law of the Sea (UNCLOS) to a case not explicitly provided for by the affirmation of the necessary interaction between UNCLOS and climate agreements; the overcoming, consequently, of an interpretation based instead on the concept of ‘fragmentation’ of international law; the definition of State due diligence obligations as obligations of conduct; the reaffirmation of the principle of common but differentiated responsibility between industrialised and non-industrialised States. The circumstance that UNCLOS says nothing about GHG emissions and, more generally, about climate change, a circumstance obviously due to the lack of perception, at the time of the Third UN Conference on the Law of the Sea, of the seriousness of the problem, was not considered by the ITLOS as an obstacle at all. The reasoning followed, on the contrary, was in the sense of interpretatively extending the obligations under UNCLOS to a case not explicitly provided for by using first of all the approach of UNCLOS itself on the matter, since its Part XII is full of references to other conventions. The ITLOS, relying on the scientific evidence offered by science, in particular the Intergovernmental Panel on Climate Change (IPCC), held that GHG emissions constitute ‘marine pollution’ within the meaning of Article 1(1)(4) of UNCLOS, arguing on the basis of the systemic integration between the UN climate change treaties and UNCLOS obligations. The TIDM thus created a link between the law of the sea and the law of climate change, which is essential in assessing the impact of the climate crisis on the oceans. Sommario: 1. La recente giurisprudenza in materia di ambiente e di contrasto ai cambiamenti climatici. – 2. Il parere consultivo del Tribunale Internazionale per il Diritto del Mare (TIDM) n. 31 del 21 maggio 2024. La riaffermazione della propria competenza in materia consultiva. – 3. Segue: la pronuncia nel merito. – 4. Conclusioni.