Invoking International Environmental Norms Through Treaty Interpretation

This article analyses the way in which international tribunals considering treaty- based disputes incorporate extraneous environmental principles through the use of interpretative mechanisms. Increasingly prominent in the international sphere, this approach allows States bringing claims under historical treaties to adopt and enforce contemporary understandings of environmental obligations. This article pursues an extensive survey of cases exhibiting this process, focusing on the interpretative techniques used; the extent to which the tribunals allowed for environmental arguments; and the basis, and use, of environmental norms. These results facilitate a comparative analysis, which concludes that tribunals’ choices regarding each of these features ultimately depends on the underlying treaty’s relationship with intertemporal law. This article thus provides a guide as to how States may effectively enforce environmental obligations, even absent explicit environmental enforcement mechanisms.