This article investigates the practices through which consensus is reached on policy-relevant scientific conclusions in intergovernmental assessment bodies. Using the case of the Intergovernmental Panel on Climate Change and the production of the Summary for Policymakers (SPM) of the Synthesis Report published in 2014, it sheds light on the procedural, visual, and rhetorical arrangements in the weaving of an intergovernmental expert consensus. Drawing on ethnographic methods, the main point of the article is that the consensus emerging from the approval of the SPM is best understood as an accumulation and juxtaposition of scientific/diplomatic consensuses. It shows that these consensuses result from a layering of compromises negotiated at various stages in the assessment process and contingent on the issues at stake and the strategies of actors. In this context, consensus is not reached on individual statements but on the document as a whole, as both authors and governments seek to have their perspectives reflected. Finally, the article draws attention to the entanglement between the scientific and diplomatic rhetoric in the fabric of the SPM, which tends to construct climate change as a decontextualized and nonpolitical problem.