Global environmental assessments assume an increasingly central role in international policymaking. Among them, the IPCC stands out as the authoritative voice of climate science. According to...Show moreGlobal environmental assessments assume an increasingly central role in international policymaking. Among them, the IPCC stands out as the authoritative voice of climate science. According to reputation theory, the maintenance of such a positive reputation requires the communication of organizational strengths to its audiences. The theory predicts patterns of emphasis and change over time, but has yet to be tested in this institutional setting. This thesis contributes to reputational theory through testing and extending its theoretical expectations to the case of the IPCC based on GEA literature. It quantitatively analyses the IPCC outputs and communication material over the course of 1994-2022, and qualitatively investigates the experience of IPCC leadership during that time. The results suggest that the IPCC becomes more reputationally aware over time, but does not diversify its legitimization strategies along hypothesized dimensions to the public - despite leadership commitment to those dimensions – but rather reinforces its technical image.Show less