The different forms and content of “Do No Significant Harm” in EU law: in search of legal certainty

Within EU law, several versions of the ‘do not significant harm’ (DNSH) principle can be identified. The chapter examines how the content and the function of the DNSH principle vary across different legal frameworks: the Communication launching the European Green Deal (EGD), the Taxonomy Regulation, and the Recovery and Resilience Facility Regulation. While the underlying logic of the DNSH principle - ensuring that progress in one environmental objective does not come at the expense of other environmental values - can be broadly shared, the analysis shows that several problematic aspects emerge from the point of view of legal certainty. Given the uncertainty in the actual content of the DNSH, it is unsurprising that its implementation also presents significant challenges, notably due to the limitations of judicial enforcement.