What is the state of research on agency in Earth system governance (ESG)? Just over a decade after the adoption of the first ESG Science Plan, this edited volume by Michele Betsill, Tabitha Benney, and Andrea Gerlak endeavors to answer this question with an original database of 322 academic articles published on the topic over that period. The ESG-Agency Harvesting Database provides the rough material for an impressive thirty contributors to analyze agency in ESG through a series of topical chapters.

Originally stemming from the simple idea that ESG involves a growing number of actors, the analytical problem of agency was included in the 2009 ESG Science Plan, and research has since generated several important insights. While it is impossible to summarize all the volume’s findings here, a number of general conclusions stand out. First, there is a wide diversity of understandings of the concept of agency in ESG research. This diversity is reflected in the edited volume itself, where “agency” can at times seem like an all-encompassing term, which can lead to some confusion.

Building on a meta-analysis of empirical research, several chapters highlight the fragmented and diversified forms of authority that govern global policy reactions to environmental issues as well as the various strategies adopted by agents in ESG. For instance, Michelle Scobie et al. find that the literature points to the multiscalar and multilevel nature of ESG, while Betsill and Manjana Milkoreit note that although states remain central to ESG, they increasingly exercise their agency alongside nonstate actors. Despite the growing complexity of international governance of the environment and the increasing interest of scholars in nonstate actors, however, Scobie et al. find that states continue to be the main object of inquiry among the articles reviewed.

Another important overarching theme of ESG-Agency research identified in the volume is the importance of power relations. In a chapter on agency and governance architecture, James Patterson notes that “power relations fundamentally condition the ability of agents to impact on regime complexes” (101–102). Meanwhile, Gerlak et al. find a disconcerting variation among conceptualizations of power in ESG-Agency literature. Some scholars adopt a more agency-centered perspective, while others perceive power as structural—and many discuss the concept without theoretical conceptualization. This variation has the effect of weakening the normative arguments made by scholars tackling these questions, a recurring problem in the empirically focused ESG body of work.

Among other key findings of this collective effort is the growing interest of scholars toward actors’ influence on processes, as opposed to previous interest in how actors influence each other and impact the environment. Furthermore, although the theme of knowledge and its interplay with agency has long been central to scholarship, Milkoreit et al. show that the focus has moved from exclusively scientific knowledge to include nonscientific knowledge forms and knowledge coproduction. Several chapters also highlight a geographic imbalance in ESG-Agency scholarship, both in terms of regions studied and the origin of scholars. On the methodological and theoretical front, Tabitha Benney et al. find that ESG-Agency scholarship largely remains qualitative and has yet to answer the call of the 2009 Science Plan to increase linkages with environmental sciences. As they point out, the field would benefit from being more inclusive on all those aspects.

Agency in ESG is a very wide field of study—so much so that it was perhaps too much to build a perfectly coherent edited volume around it. While some chapters focus on general concepts and their linkages with agency, others are centered around empirical problems, the only connecting thread being the agency of actors. For example, a chapter on the interplay between agency and norms bears only a tenuous link to another on agency in the allocation of natural resources, and each would certainly have been deserving of a full volume. The fact that “agency” and several other important concepts are conceptualized inconsistently in the literature made the elaboration of this volume an ambitious project. Moreover, the nature of the book as a synthesis of ten years of diverse scholarly work can, at times, make the reading somewhat strenuous, as the authors discuss a long series of findings.

These are nevertheless small shortcomings that would hardly have been avoidable in this kind of endeavor. Overall, Agency in Earth System Governance achieves its goal of presenting and reflecting on the results of the first ten years of ESG-Agency research, and its weaknesses are generally attributable to the shortcomings of the literature itself. The volume is well structured and easy to navigate, as every chapter begins with a short, synthesized list of its findings. The conclusion, in which the editors and several of their collaborators examine the policy implications of their results and recommend future research avenues, will be of particular interest to scholars and practitioners of global environmental governance. The volume marks a crucial step in ESG research in general, a few years after the second Science Plan of the ESG Project.