The Intergovernmental Panel on Climate Change (IPCC) has become a hugely influential institution. It is the authoritative voice on the science on climate change, and an exemplar of an intergovernmental science-policy interface. This book introduces the IPCC as an institution, covering its origins, history, processes, participants, products, and influence. Discussing its internal workings and operating principles, it shows how IPCC assessments are produced and how consensus is reached between scientific and policy experts from different institutions, countries, and social groups. A variety of practices and discourses – epistemic, diplomatic, procedural, communicative – that make the institution function are critically assessed, allowing the reader to learn from its successes and failures. This volume is the go-to reference for researchers studying or active within the IPCC, as well as invaluable for students concerned with global environmental problems and climate governance.