Climate change engagement cannot be explained by knowledge alone; it also depends on how seriously individuals perceive the threat and whether they believe effective action is possible. This study examines the relationships among climate change literacy, risk perception, self-efficacy, collective efficacy, climate action intention, and support for climate policy among Korean adults. Using data from an online survey (N = 300), structural equation modeling was employed to estimate a model in which climate change literacy is associated with perceived risk, and perceived risk is in turn associated with climate action intention and policy support. The results indicate that climate change literacy did not have direct effects on climate action intention or policy support. Instead, literacy was indirectly related to both outcomes through higher levels of perceived risk. Risk perception emerged as the strongest predictor of both climate action intention and policy support. Collective efficacy-the belief that society can effectively address climate change through joint effort-was more strongly associated with climate action intention than self-efficacy, which showed a comparatively weaker relationship. Climate action intention significantly predicted support for climate policy. The final model explained 52.3% of the variance in climate action intention and 68.9% of the variance in policy support. Overall, the findings suggest that climate engagement in Korea is more closely associated with shared perceptions of risk and collective agency than with individual confidence alone. These results imply that strategies emphasizing collective responsibility and coordinated action may be more effective than approaches relying solely on individual appeals or the provision of factual information.