IMPULS Michael A. Mehling A New Climate: Europe in the Long Shadow of Trump 2.0 Climate Leadership and the‘Brussels Effect’ at a Crossroads At a glance The return of the Trump administration has fundamental­ly altered the landscape of transatlantic climate and ener­gy cooperation. Unlike earlier episodes of US disengage­ment, Trump 2.0 marks a shift from passive withdrawal to active obstruction, with direct implications for European climate ambition, international coalition-building, and the global pace of decarbonisation. This policy paper argues that much of the EU’s climate policy architecture draws on concepts first developed in the United States, creating a structural dependence that becomes untenable when the originating country turns against climate action. Drawing on expert consultations and recent policy analysis, it trac­es the‘Trump Effect’ across three dimensions: domestic US rollback, transatlantic friction, and erosion of the‘Brussels Effect’ as a mechanism of global coordination. It then out ­lines a strategic reorientation for European climate policy, centred not on moral leadership but on economic security, industrial competitiveness, and diversified international partnerships. The paper concludes with concrete action points aimed at anchoring EU climate ambition in strate ­gic autonomy while sustaining engagement with subna ­tional US actors, middle powers, and emerging economies. 1. Introduction The European Union continues to present itself as a global climate leader, yet its climate and industrial policies remain deeply exposed to external power dynamics, above all those originating in the United States. The second Trump presidency exposes a structural dilemma: how to sustain ambitious climate action when Europe’s closest ally is an unreliable and increasingly hostile climate actor. This is not merely a diplomatic inconvenience. As this paper argues, much of Europe’s climate policy architecture draws on con­cepts and instruments first developed in the United States, A New Climate: Europe in the Long Shadow of Trump 2.0 1