Platforms, multimedia, and AI-mediated engagement in institutional climate communication: Evidence from COP28 digital campaigns

This study examines how institutional climate communication campaigns associated with 2023 United Nations Climate Change Conference (COP28) strategically deploy multimedia and artificial intelligence (AI)-assisted tools across social media platforms to shape public engagement. Adopting a mixed-methods research design, the study combines quantitative analysis of platform engagement metrics using PLS-SEM modeling with a complementary qualitative thematic reading of publicly available audience comments on Facebook, Instagram, YouTube, X (Twitter), and LinkedIn. The quantitative findings indicate that semantic-rich video content is positively associated with higher audience engagement (β = 0.50, p = 0.007), AI-enabled content personalization is associated with improved campaign effectiveness measured through click-through and conversion indicators (β = 0.42, p = 0.020), and interactive multimedia features are associated with stronger user interaction and retention (β = 0.57, p = 0.004). These results are interpreted through media richness and social presence perspectives, alongside platform-based communication logics that emphasize the role of algorithmic visibility, data-driven optimization, and sociotechnical affordances in shaping institutional publics online. The study contributes to social media scholarship by extending empirical evidence on AI-mediated multimedia engagement to the domain of institutional climate communication, while highlighting implications for responsible personalization, transparency, and public trust within platform environments.