Unprecedented climate change. Far-reaching chemical pollution. Accelerating species loss. These are just a few of the global environmental challenges we face today. The international community has sought to develop coordinated responses to these threats, including through the myriad multilateral environmental agreements (MEAs) that have been signed over the past half-century.1 And, as the international community has increasingly turned to environmental treaties to address this accelerating cascade of global challenges, it has also become common to institutionalize the provision of science advice at a global scale through the establishment of dedicated science committees. These science committees are commonly cast as technical bodies whose task is constrained to assessing existing knowledge, often already validated through processes such as peer review. Such a representation of their work is also used in service of arguments that justify black-boxing, or insulating and removing from public scrutiny, their proceedings. Indeed, their output is routinely considered just an apolitical contribution to a complex decision-making process.

In contrast, this book centers on these science committees established to guide parties to an MEA. How are scientists and other knowledge holders called upon to contribute as experts? How do they organize their work, and to what effect? Opening up the proceedings of these committees demonstrates that these technical fora are a significant setting for the shaping of global environmental governance once treaties enter their implementation phase. These specialized committees are sites where participants are simultaneously working out understandings of global earth systems as well as how to govern them.

Expert institutions that are asked to provide advice for the implementation of international environmental treaties are understudied. The provision of science advice for policymaking at the national and regional levels has, in contrast, been the focus of myriad in-depth research efforts. These latter studies have yielded insights into the importance of varied aspects of the design and operation of science advice institutions. These findings include, to name but a few, a recognition of how science advisers shape policymaking outcomes (Jasanoff 1990), explorations of how strategic choices about transparency influence uptake of advice (Hilgartner 2000) and myriad examinations of the promise, and pitfalls, of broadening participation (Chilvers and Kearnes 2015). Yet, there have been limited applications of such scholarship to science advice committees operating at the global scale.