How can a diversity of perspectives be accommodated in scientific and political consensus on environmental issues? This paper adopts a science and technology studies (STS) approach to examine how the pursuit of consensus-based knowledge and diverse participation, as seemingly contradictory commitments, have been converted into practice in the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Through a series of negotiations, these commitments have been translated into a set of situated practices that now dominate this expert panel. Consensus has been achieved through the pursuit of closure, in which meetings of expert and administrator groups produce texts, tables and images that stabilise ostensibly collective decisions. Within this framework, diverse perspectives have been accommodated through the production of typologies, such as lists of comparable options, which allow for the coexistence and commensurability of a range of knowledges and experts. However there is a politics to typologies, which requires specific attention to how decisions are made (deliberation), who participates in them (participation), and the extent to which these participants are representative of broader knowledge and policy communities (representation). While the potential of typologies to accommodate consensus and diversity offers the hope of realising ‘unity in diversity’ for both environmental knowledge and policy, recognising the politics of their production is important for more equitable processes of environmental governance.