Public discourse on critical issues such as climate change is progressively shifting to social media platforms that prioritize short-form video content. Content creators acting on those platforms play a pivotal role in shaping the discourse, yet the dynamics of communication and audience reactions across platforms remain underexplored. To improve our understanding of this transition, we studied the video content produced by 21 prominent YouTube creators who have expanded their influence to TikTok as information disseminators. Using dictionary-based tools and BERT-based embeddings, we analyzed the transcripts of nearly 7k climate-related videos across both platforms and the 574k comments they received. We found that, when publishing on TikTok, creators use a more emotionally resonant, self-referential, and action-oriented language compared to YouTube. We also observed a strong semantic alignment between videos and comments, with creators who excel at diversifying their TikTok content from YouTube typically receiving responses that more closely align with their produced content. This suggests that tailored communication strategies hold greater promise in directing public discussion toward desired topics, which bears implications for the design of effective climate communication campaigns.

翻译：关于气候变化等关键议题的公共讨论正逐渐转向以短视频内容为主的社交媒体平台。这些平台上的内容创作者在塑造公共话语方面发挥着关键作用，然而跨平台间的传播动态与受众反应机制仍未得到充分探索。为深化对这一转变的理解，本研究追踪了21位颇具影响力的YouTube创作者——他们已将影响力扩展至TikTok平台并成为信息传播者。通过基于词典的分析工具与BERT词向量嵌入技术，我们解析了约7000个跨平台气候变化相关视频的文本记录及其收到的57.4万条评论。研究发现，相较于YouTube平台，创作者在TikTok发布内容时更倾向于使用情感共鸣型、自我指涉型和行动导向型的语言。同时观察到视频与评论之间存在显著的语义对齐现象：那些擅长将TikTok内容与YouTube形成差异化表达的创作者，其收到的受众反馈通常与其制作内容具有更高的一致性。这表明，定制化传播策略在引导公众讨论聚焦特定议题方面具有更大潜力，这为设计有效的气候变化传播活动提供了重要启示。