This article explores how the Intergovernmental Panel on Climate Change (IPCC) has dealt with growing public scrutiny of its workings. It reviews recent initiatives set up to respond to the Climategate controversy. An independent review of the IPCC undertaken by an international scientific umbrella body—InterAcademy Council—can be shown to have triggered one of the turning points in the debate, placing the focus of attention on the IPCC's transparency and accountability. However, the council's recommendations have been implemented by the IPCC in such a way that the issue of public trust is treated as one of effective communication. The article then explains how IPCC's responses to Climategate can be traced back to the linear model of expertise. The article concludes with a discussion why the challenge of producing policy-relevant knowledge under conditions of heightened public scrutiny also requires new forms of scientific appraisal aimed at wider publics.