What facilitates public engagement? A study on communication actors and agenda-setting in climate communication

Purpose This study aims to explore how communication actors and topic attributes shape climate discourse on Chinese social media, aiming to reveal prevailing issue agendas, actor–topic preferences, misinformation patterns and their influence on public engagement. Design/methodology/approach Drawing on Second-Level Agenda-Setting Theory and the Public Engagement with Science (PES) framework, the study analyzes 24,690 climate-related posts collected from Weibo. Latent Dirichlet Allocation was used to extract thematic categories, while content coding identified communicator types. Regression analysis and chi-square tests were used to examine how thematic salience and actor identity influence engagement metrics (likes, reposts, comments) and misinformation patterns. Findings The findings reveal a hybrid climate agenda structured around international relations, domestic policy and technological development, reflecting the integration of climate discourse into broader national priorities. Public users dominate content production and account for the vast majority of climate misinformation. Engagement patterns vary systematically across actor–topic combinations: politically and risk-oriented themes elicit stronger public responses, while non-governmental organizations (NGOs) and corporations outperform traditional institutional actors in generating engagement. Originality/value This study advances climate communication research by explicitly integrating Second-Level Agenda-Setting Theory with the PES framework to link agenda attributes to observable engagement behaviors in a non-Western, state-regulated digital environment. Methodologically, it demonstrates the value of combining scalable computational topic modeling with engagement metrics to analyze large-scale social media discourse. Substantively, the findings offer actionable insights for communicators, platform managers and policymakers seeking to enhance public engagement and address climate misinformation in collectivist and policy-centered media systems.