− ESG–Agency scholarship highlights the fragmented, expanding, and complex forms of authority that prescribe, steer, and govern behaviour on environmental issues. − Agency scholarship on earth system governance covers interdisciplinary debates in four broad areas: the types of agents, the ways authority is exercised, the nature of agents’ influence, and the varieties of governance structures or architectures within which agents act.− Even with increasing scholarship into the fragmentation of authority and multiplication of the types agents to include nonstate, transnational, and subnational actors, states continue to be the centre of agency scholarship. Future research is needed on agency theory and the theoretical nature of relationships between actors and within differing geographic, economic, and political contexts.

− Agency is one of five core analytical problems in the Earth System Governance (ESG) Project’s research framework, which offers a unique approach to the study of environmental governance. − Agency in Earth System Governance draws lessons from ESG–Agency research through a systematic review of 322 peer-reviewed journal articles published between 2008 and 2016 and contained in the ESG–Agency Harvesting Database.− ESG–Agency research draws on diverse disciplinary perspectives with distinct clusters of scholars rooted in the fields of global environmental politics, policy studies, and socio-ecological systems. − Collectively, the chapters in Agency in Earth System Governance provide an accessible synthesis of some of the field’s major questions and debates and a state-of-the-art understanding of how diverse actors engage with and exercise authority in environmental governance.

− Over the last decade, ESG-Agency scholars have increased their use of social and system dynamic theories, participatory and actorness approaches in agency theories, and justice approaches within critical theories.− Qualitative and multiple qualitative methods are the most widely used approaches in research on agency in earth system governance, with very slowly growing methodological pluralism. − In the future, scholars in this field may benefit from the integration of cross-disciplinary and increasingly complex methods in an effort to foster linking of environmental sciences more broadly into environmental governance research.

− The role of the state as an agent of earth system governance has become more complex, contingent, and interdependent. − Although participatory and collaborative processes have contributed to more effective, equitable, and legitimate environmental governance outcomes in some instances, analyses of these processes should be situated within a broader governance perspective, which recasts questions of policy change around questions of power and justice. −The complexity and normative aspects of agency in earth system governance requires new forms of policy evaluation that account for social impacts and the ability of governance systems to adapt. − Many of the core analytical concepts in ESG–Agency scholarship, such as agency, power, authority, and accountability, remain under-theorized. In addition, some types of actors, including women, labor, non-human agents, those who work against earth system governance, and many voices from the Global South, remain largely hidden. − ESG–Agency scholars need to develop research projects and collaborations in understudied regions while also recruiting and supporting scholars in those regions to engage with this research agenda.