Across the Member States of the European Union (EU), there is a renewed emphasis on environmental law enforcement as the right of access to justice guaranteed by the Aarhus Convention takes effect. This paper focuses specifically on the contemporary role of the Court of Justice of the EU in promoting access to justice in environmental matters at national level. In a series of decisions over the seven year period 2009 to 2016, the Court has drawn on the Aarhus Convention and the EU legislative measures giving effect to the Convention to justify a more interventionist approach to national procedural rules and remedies and to underpin the proactive enforcement of environmental law. By engaging in close analysis of this particular line of jurisprudence, the paper demonstrates how the Aarhus Convention has led the Court to develop a new and highly dynamic phase in the evolution of environmental law enforcement. In effect, the access to justice obligations articulated in the Convention have emboldened the Court to flesh out specific elements of the principle of effective judicial protection as it applies to environmental law enforcement in the Member States.