Convergence and coordination in the C40 emerged as a function of the authority of Michael Bloomberg and New York City to establish and project onto the governance field a particular set of governance norms and a sense of collective identity. This chapter demonstrates the extent to which convergence around those norms and identity not only continued, but also rather accelerated, following the shift in C40 leadership that took place in early 2014. The analytic focus thus shifts from an emphasis on agency – who claims authority, how actors attempt to shape the substance of the governance field – to the structuring effects that governance fields exert once those ideational and identity contours are entrenched. The chapter documents the extent to which the C40 governance field, from 2014-2018, consolidated around governance norms of autonomous agency and global accountability. The theory of global urban governance fields is deployed to illuminate the manner in which these norms constitute both the parameters within which member cities have come to understand and enact their role as global climate governors, and the mechanism of recognition through which these norms are replicated and reinforced across the C40.

The C40 is in many ways a success story. It has generated increased engagement and coordination, with the vast majority of member cities now committed to the collective goal of carbon neutrality by midcentury. This level of coordination was virtually unthinkable a mere decade ago, and the theory of global urban governance fields helps to identify and explain its origins and underpinnings. The ability of the C40 to generate convergence and consolidation around a common understanding of how to “be” a global urban climate governor has enabled the C40 to generate collective effort in the face of voluntary participation. This chapter sets out the ways in which this insight contributes to pushing forward the scholarship on cities, global climate governance, and the role of cities in international relations more broadly. It also highlights important questions that emerge as a result, including the relationship between the content of C40 norm/identity convergence and the potential contribution it can make to achieving collective goals of decarbonization and transformative sustainability, how to measure and assess progress and performance, and for whom/to whom cities are rendering themselves accountable as global climate governors.

Interplay management involves deliberate efforts by one or more actors to improve the interplay of institutions set up for earth system governance. This chapter synthesizes two decades of conceptual and empirical research on the conditions that influence the conduciveness of interplay management to earth system governance. Those conditions concern the agency and the means of management, notably whether interplay management proceeds by means of coordination or adaptation, as well as the compatibility of the policy objectives pursued. Agents of interplay management are states, intergovernmental organizations and industry- or civil-society groups, seeking to mobilize assets such as material resources, expertise or legitimacy held by one institution to promote objectives pursued under another. Means employed are frequently variants of unilateral adaptation to norms and programmes undertaken in other institutions, rather than explicit coordination involving joint decision-making. Cross-institutional coordination has obvious advantages and is particularly valuable when the institutions govern highly interdependent activities or can bring to bear complementary capacities. With clearly competitive elements present, adaptation has the advantage of triggering less turf-sensitive resistance.

This chapter reviews the literature on transnational institutions and networks in earth system governance research over the past decade. The chapter focuses in particular on the issues of emergence, effectiveness and legitimacy of transnational governance and outlines key debates and controversies surrounding the shifting authority between public and private actors. The chapter also identifies major research lines and open questions and provides an outlook towards the most promising directions in future research. The review is based on 215 articles identified in the Web of Science (co)authored by fellows of the Earth System Governance Project from 2008 to 2018.

Orchestration is a soft mode of governance, in which a ‘governor’ enlists the voluntary cooperation of intermediary actors to carry out governance functions that further the governor’s goals. Environmental issues figured prominently in the origin of the orchestration concept, and orchestration has since played a significant role in earth system governance research on architecture and agency. This chapter summarizes key empirical findings of this research, especially on sustainable development and climate change. It also identifies contributions of earth system governance research to orchestration theory: for example, concerning the conditions for successful orchestration, the role of orchestration platforms and orchestration’s role in institutional complexity. The chapter then engages with critiques and normative concerns, particularly relating to power, accountability and legitimacy. The chapter concludes with thoughts on an orchestration research agenda that can support the transformative goals of the new earth system governance science plan.

Hierarchization is a deliberate process to create a vertically nested governance architecture where actors and institutions in a lower rank are bound or otherwise compelled to obey, respond to or contribute to higher-order norms and objectives. Drawing on this definition, we review recent research on hierarchization in earth system governance and the political and legal processes that establish, maintain and legitimize it. Here we present three mutually non-exclusive forms of hierarchization – systematization, centralization and prioritization. Each involves different actors and rationales, mechanisms and strategies, while achieving different purposes with varying governance outcomes. We illustrate our argument with empirical examples including the proposed Global Pact for the Environment, the proposal to establish a world environment organization and the Sustainable Development Goals. We conclude with an assessment of the benefits and drawbacks of hierarchization as an approach to some of the challenges inherent in earth system governance, and offer suggestions for future research.

There is a growing consensus in the literature that governance architectures matter. However, we lack sufficient knowledge about their emergence, dynamics and impacts. This concluding chapter summarizes all insights in the book Architectures of Earth System Governance, and emphasizes how this book has made a scientific contribution by enhancing conceptual clarity, synthesizing a decade of intense research, and charting directions for future research. The book has made at least one point clear: the ‘architecture lens’ offers a bird’s-eye view on the global governance landscape that is highly valuable in explaining outcomes of world politics. The architectures matter in how institutions interact with others, how institutions are entangled with others in larger regime complexes and how institutions are affected by broader architectures that are more or less fragmented or polycentric. In this concluding chapter, we also illustrate how such key insights gained could inform a set of transformative policy proposals regarding the architecture of earth system governance.

Environmental policy integration (EPI) is the incorporation of environmental concerns and objectives into non-environmental policy areas, such as energy, transport and agriculture, as opposed to pursuing such objectives through purely environmental policy practices. EPI is promoted to overcome policy incoherence and institutional fragmentation, to address the driving forces of environmental degradation and to promote innovation and synergy. But how effective are EPI strategies employed in practice? In this chapter we provide a meta-analysis of scientific, empirical research on EPI to address this question. An important finding is the discrepancy between the adoption of EPI in terms of objectives and commitments and its actual implementation, that is, translation into concrete measures. Overall, we found relatively few cases where environmental objectives were given a substantial status in non-environmental policies. The barriers we identified suggest that the actual detailed design or architecture of the strategies that are employed to promote EPI really matters.

Governance through goals, a relatively new global governance mechanism, has recently gained prominence, particularly since the adoption of the Sustainable Development Goals. Through this mechanism, internationally agreed policy goals orchestrate the activities of governmental and non-governmental actors. This chapter argues that governance through goals has important effects on governance architectures and their degree and type of fragmentation. To analyze these effects, we review literature around four characteristics of governance through goals: their non-legally binding nature, weak global institutional arrangements, inclusive goal-setting processes and national leeway. We argue that alternative forms of bindingness, such as reporting and accountability mechanisms, can steer actors toward a shared vision. This may result in synergistic fragmentation if broad support is obtained through inclusive processes. However, tensions and cherry-picking may arise when goals are prioritized and implemented. Further research on the effects of governance through goals is crucial given that it is likely to maintain – and gain – importance in earth system governance.

The theory of global urban governance fields asserts that coordination in city-networks rests on convergence around a common set of ideas and practices that shape how member cities understand themselves as global climate governors. This chapter applies cluster analysis to a dataset containing both 10,000-plus unique climate governance actions, as well as the climate governance profiles (type and content of emissions reduction target, scope and methodology of emissions inventory, focus and scope of climate action plan) of all C40 cities, to infer the governance norms and collective identity around which the C40 governance field has been organized. The analysis posits two core ideational components – what kind of agency do cities possess, and how do they orient themselves to the global effort – and identifies convergence over time and space around two distinct responses: governance norms of autonomous agency and global accountability. These norms, in concert with practices of standardization, transparency, accounting, and disclosure, constitute a collective identity: the globally accountable urban governor. The chapter provides empirical referents for this process of normative and identity convergence, and establishes the connection between these and observations of increased coordination and collective effort.