Carrasco Polaino, Rafael2026-01-142026-01-142026Carrasco-Polaino, R. (2026). Public Conversation on X During COP30: Engagement, Sentiment and Thematic Dynamics Around #COP30noBrasil. Social Sciences, 15(1), 21. https://doi.org/10.3390/socsci1501002110.3390/socsci15010021https://hdl.handle.net/20.500.14352/130229This study examines how public conversation on X unfolded during the COP30 climate summit, focusing on posts articulated around the official hashtag #COP30noBrasil and analysing a dataset of 1139 posts. Social media research has shown that platforms such as X play a central role in shaping climate communication, particularly during major diplomatic events. To explore this dynamic, all posts published between 10 and 21 November 2025 were collected using Tweet Binder and analysed quantitatively. Engagement, follower–following ratio and sentiment were computed, and non-parametric tests were applied given the non-normal distribution of the variables. Word clouds based on frequency and TF–IDF weighting were generated to identify prevalent topics in posts and replies. The results showed that activity was dominated by retweets, with original posts and replies representing smaller portions of the interaction. Engagement did not differ significantly between verified and unverified accounts, although posts with images generated higher interaction than text-only posts. No significant correlations emerged between engagement, sentiment or FF ratio. Replies displayed a less positive tone than original posts, suggesting a shift toward more neutral reactions. The thematic analysis indicated that original posts centred on planning and institutional aspects of COP30, while replies focused more on Amazon-related issues, resource extraction and calls for environmental protection.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal articlehttps://doi.org/10.3390/socsci15010021https://www.mdpi.com/2076-0760/15/1/21open access316.77316.775.4502Climate communicationSocial media analysisCOP30Comunicación socialAudiencia y difusión de los mediosMedio ambiente natural6306.07 Sociología de Los Medios de Comunicación de Masas5910.02 Medios de Comunicación de Masas5902.08 Política del Medio Ambiente