This paper focuses on the methods of enforcement specific to international environmental treaties. In this area, non-compliance procedures were created to respond to the specificities of international environmental obligations, as an alternative to international courts and tribunals, putting into question the role of such courts and tribunals. Comparing non-compliance procedures with formal dispute settlement allows us to redefine the contours of international adjudication. Therefore, relationships between non-compliance procedures and international courts will be analysed. A core question is whether or not both mechanisms are “competitors” excluding each other or “guarantors” working together, and which of these cases strengthen environmental protection. In other words: how do they interact? Could potential coordination enhance environmental protection? This paper will explore different models on which their relationship can be based.