Global governance consists of elementary regimes that form regime complexes, which in turn give rise to what we call superclusters around broad policy domains. In recent years, scholars have explored what these macroscopic structures look like and how they evolve over time. Yet the complex ways in which entire governance superclusters interact and coevolve, and what might emerge through this process, have not received much attention. In this article, we expand the ontological frontier of global governance research by offering a first bird’s-eye view on supercluster-level institutional interaction with an empirical focus on trade and environment. We constructed and analyzed a dynamic network-of-networks model, revealing a supercluster complex , a massive institutional structure in global governance consisting of two or more interlocking superclusters that exert a measurable influence on each other’s course of development. We theorize that the supercluster complex serves as an institutional fabric that enables the degree of self-organized coordination observed between the trade and environment policy domains. Our preliminary findings warrant more research on supercluster complexes as an important but little-noticed phenomenon in global governance.

Initiated in 2002, the International Environmental Agreements Data Base (IEADB) catalogs the texts, memberships, and design features of over 3,000 multilateral and bilateral environmental agreements. Using IEADB data, we create a comprehensive review of the evolution of international environmental law, including how the number, subjects, and state memberships in IEAs have changed over time. By providing IEA texts, the IEADB helps scholars identify and systematically code IEA design features. We review scholarship derived from the IEADB on international environmental governance, including insights into IEA membership, formation, and design as well as the deeper structure of international environmental law. We note the IEADB’s value as a teaching tool to promote undergraduate and graduate teaching and research. The IEADB’s structure and content opens up both broad research realms and specific research questions, and facilitates the ability of scholars to use the IEADB to answer those questions of greatest interest to them.