At the international level, institutions of global expert advice responsible for the provision of policy-relevant knowledge are in increasing demand. In particular, since the creation of the Assessment panel on Ozone in the early 1980s, global environmental assessments (GEAs) have become increasingly relied upon with the most prominent example being the Intergovernmental Panel on Climate Change (IPCC, 1988) and, more recently, IPBES. Mitchell and colleagues de¿ne assessments “as formal e¿orts to assemble selected knowledge with a view toward making it publicly available in a form intended to be useful for decision making” (Mitchell et al., 2006: 3). Underlying these organizations is the assumption that scienti¿c knowledge and experts have a key role to play to address pressing environmental issues such as climate change or biodiversity loss. In doing so, GEAs contribute to the de¿nition of the “problem” at stake while delineating whose knowledge and expertise should be included in conducting assessments. Implicitly or explicitly, they operate with particular conceptual frameworks which play an important role in delineating what counts as useful or policy-relevant knowledge. According to its own terms, IPBES aims to “strengthen the science-policy interface for biodiversity and ecosystem services for the conservation and sustainable use of biodiversity, long-term human well-being and sustainable development”.1 In order to address this ambitious objective, IPBES has adopted a conceptual framework to be used in all functions of its mandate, currently organized around four functions including providing: (1) assessments, (2) policy-support tools, (3) knowledge generation and (4) capacity-building. Science-policy interface (SPI) research has been ¿ourishing. SPIs are generally conceived as “social processes which encompass relations between scientists and other actors in the policy process, and which allow for exchanges, co-evolution, and joint construction of knowledge wi