Climate Change (CC) is the greatest threat to our society, but although science presents evidence of the magnitude of the problem and accurately describes the consequences, people are not acting enough. The reason behind this paradox could be the inappropriate Social Representation (SR) on CC in society and may explain why there are still skeptical and denialist beliefs, as well as their inadequate communication. A quasiexperimental design with pre-test and post-test verified whether well-designed MOOCs based on scientific evidence can improve SR on CC, generating awareness and effective mobilization to address this important issue.