This final chapter reviews some of the principal arguments put forward in the volume, synthesizing the quite diverse contributions made. It highlights how each of the authors has conducted their study based on a particular conceptualization of our current socio-ecological context, whether this be through an understanding of the ‘Anthropocene,’ or by using alternative terms such as the ‘Capitalocene’ or the ‘Technocene’. Yet, the principal aim of this conclusions chapter is to interrogate the ontopolitical commitments inherent in each of these different framings. This ‘ontopolitics of critique’ illustrates how the authors’ ontological assumptions vis-à-vis the nature of our socio-ecological reality harbor important political implications. The ways that the authors negotiate the ‘culture’-‘nature’ opposition are a key concern in this regard, and it is shown how this has an important bearing on the political possibilities which open out before them vis-à-vis human agency and the transformation of existing political structures. This final chapter, thus, elaborates the main contribution made by the volume to the field of International Relations (IR): it showcases how different conceptualizations of the ‘Anthropocene’ can be used to study some key topics in the field of IR, while also highlighting how these approaches invariably rest on ontopolitical assumptions which are ultimately contestable. As progressive climate change continues to radically alter environmental conditions, this Conclusions chapter makes the case for continued and unending critical engagement with the ontopolitics of the ‘Anthropocene,’ both within and beyond the field of IR.