In line with the IPCC’s own mandate to select a more diverse group of experts to contribute to their assessments, the proportion of women and participants from the Global South has increased over recent assessment cycles. Criticisms remain, however, over the continued dominance of experts and institutions of the Global North, the relative place of different disciplinary and transdisciplinary knowledges in assessments, and the extent to which, once selected to participate, underrepresented groups have the space and opportunity to speak and be heard. Taken together, these criticisms point to a particular weakness of the diversity agenda – that once an imperative to diversity has been institutionalised, it becomes just another target or metric to be gamed. As a top-down, depoliticised measure, institutional diversity can serve to obscure – or even exacerbate – continued the institutional exclusion of marginalised groups. This article proposes a move away from the concentration on diversity as an indicator of the plurality and epistemic strength of an organisation, towards a focus on the politics representation. This move is radical in two specific ways: firstly, it entails more openness and transparency from the IPCC over how their assessments are produced. Representation cannot be easily quantified but must be observed and analysed qualitatively. Secondly, it understands that, unlike diversity, representation requires agency and capacity, signifying a different relationship between the IPCC and the participant. Representation is thus conceptualised as a more political, yet more impactful way of extending the IPCC’s policy (and social) relevance.