<p>Social media are increasingly used as supplements or alternatives to traditional sources for obtaining climate change information. This study aims to explore the mechanisms through which social media exposure, perceived threat, perceived efficacy, and skepticism influence both media behavioral intentions (information seeking) and offline behavioral intentions (climate change mitigation), applying the extended parallel process model and the social amplification of risk framework in China. Structural equation analysis indicates that social media exposure positively predicts perceived efficacy but does not significantly predict perceived threat, and it has both direct and indirect effects on behavioral intention. The research findings extend the EPPM by confirming its additive effects, specifically the independent main effects and cumulative effects of perceived threat and perceived efficacy on behavioral intention, with perceived efficacy being the most important driver. The study also highlights how skepticism interacts with social media exposure to shape individuals’ perceptions of climate change risk and their intentions to engage in climate action.</p>