ABSTRACT
In this chapter, the role of the principle of sincere cooperation in the implementation of EU environmental law is discussed. Firstly, the principle of sincere cooperation is presented as a general principle of EU law. European environmental legislation underlines the obligation for Member States and EU institutions, bodies and agencies to cooperate. However, the sincere cooperation principle underlines the implementation of EU environmental legislation even without reference to that principle. The principle of sincere cooperation is also an underlying principle in the Court of Justice of the EU's (CJEU) jurisprudence on the obligations of the Member States to implement EU environmental law effectively. The transboundary nature of pollutants and the risk of transferring pollution from one state to another requires more cooperation between Member States than in any other EU policy. The fulfilment of these obligations is enforceable in cases before the CJEU, which makes the principle of sincere cooperation a real instrument providing for a more effective implementation of EU environmental law in both internal and external dimensions.
