Communicating Planetary Health: A Mixed-Methods Study on Trust in Communicators in the Climate and Health Domains

Effective communication about climate change, climate action, and their health impacts is central to the Planetary Health approach, which emphasizes the inseparable linkage between safeguarding human well-being and protecting ecological systems. Prior research indicates that trust shapes individuals’ readiness for climate action. Accordingly, the perceived credibility of communicators, particularly their trustworthiness, is a central driver of audiences’ acceptance of information and recommendations. Guided by Source Credibility Theory and the Elaboration Likelihood Model, this mixed-methods study examines which communicators are perceived as trustworthy in integrated climate–health communication and whether expert recommendations align with public trust.The study combined qualitative interviews and an online survey with open-ended responses from experts across various fields, followed by a quota-representative survey of the German general public (N = 1,130). Experts nominated communicators across scientific, medical, institutional, educational, and community-based sectors and made stronger distinctions between communicators for climate action and health topics. In contrast, public trust patterns were highly consistent across both domains, largely independent of the communication topic. Scientists, medical professionals, and public health institutions received the highest trust ratings, whereas the federal government and public figures were trusted the least.Overall, the results highlight alignments and discrepancies between those who shape communication strategies and those who receive them. Aligning communication strategies with audience perceptions of credibility and integrating trusted professional and community-based communicators may strengthen Planetary Health communication and enhance readiness for climate action.