This chapter describes the journey that the scientific assessment travels from author nomination through to the drafting and reviewing of the emerging report, and explores the social scientific order that structures and imprints on the IPCC’s writing of climate change through the process. It is in the initial stages of the scientific assessment, in the government nomination and author selection processes, that asymmetries in global knowledge of climate change and their effects become apparent. While developed countries have institutionalised processes for identifying and nominating experts, the majority of developing countries do not submit any author nominations. Once compiled, it is scientific conventions and measures of authority that are used to select and appoint the expertise necessary to fulfil the government approved outline of the report. However, when these activities are situated in broader patterns and practices of knowledge production, it becomes apparent that these reproduce the structures and exclusions of the existing global knowledge economy. These asymmetries are also apparent in the order of relations in the author teams and the submission of government review comments, which reduces the space for more diverse understandings and knowledges of climate change that are relevant to and reflect the interests and needs of all IPCC member governments. The IPCC has attempted to address these asymmetries through selection criteria and other mechanisms to shape the social order of authorship, which to date have proven more successful in broadening gender representation than ensuring the full participation of developing country authors in the assessment.