This chapter focuses on the external dimension of EU environmental law and discusses the main developments that the Lisbon Treaty brought in this particular area, in the light of the practice of the EU institutions and the Member States, as well as the case law of the Court of Justice of the European Union (CJEU). Accordingly, we will first sketch out the competence and legal bases for EU external environmental action. Against this backdrop, we will look into how the EU has implemented the mandate of environmental integration, in order to ensure the consistency of its external environmental policy with other areas of EU external action, such as in particular the Common Commercial Policy (CCP). Finally, we will assess how the EU participates in international environmental negotiations. The chapter concludes with an evaluation of the EU´s track record as a global actor in international environmental governance.