This chapter explores the transboundary nature of environmental harms and how they have shaped the governance of environmental policing in unique ways. It argues that the ‘cooperation imperative’ demanded by global environmental problems has for sometime been shifting thinking and practice toward new responses to environmental harms. The most recent iterations of these new approaches are characterised as ‘New Environmental Governance ́ (NEG) that emphasizes collaboration, integration, participation, deliberative styles of decision-¬making, adaptation and learning. This emerging nodal approach is premised on the notion that complex environmental and social systems cannot readily be governed by a single actor, namely, a government acting alone. The chapter highlights shifts in the thinking and arrangements for governing environmental security, from traditional environmental enforcement to markets, early forms of partnerships and finally NEG. Examples of NEG are examined and key benefits to policing and transboundary environmental harms are explored. Recent debates are highlighted, with a focus on whether nodal forms of environmental governance such as NEG can deliver on their promised benefits to offer a more effective, efficient and legitimate resolution to environmental harms than traditional modes of environmental policing. The chapter concludes by setting out emerging issues and new areas of analysis for understanding and explaining environmental problems and policing.