Climate change has been increasingly discussed in moral terms in public discourse. Despite the growing body of research on the effectiveness of moral frames in bridging the ideological divide, few studies have examined the role that perceived credibility, an important element of any persuasive appeal, plays in facilitating the framing effect. With the objective of further understanding how moral frames may engage individuals with different ideologies in climate change and refining climate change messaging strategies, two experimental surveys were conducted to examine the effects of moral violation frames on climate engagement. Specifically, a moderated mediation model was tested. The model posits that message credibility mediates the relationship between moral frames and policy support, as well as the relationship between moral frames and behavior intention. Moreover, political ideology moderated the indirect effects of message credibility. Based on moral foundations theory, seven messages were designed to activate individualizing and binding moral foundations. The results indicated that credibility consistently mediated the effects of the moral violation frame on climate engagement and that liberal-leaning individuals were more likely to perceive an individualizing frame as more credible than a binding frame. However, this difference was smaller among conservative-leaning individuals, with evidence for this moderated mediation model found only for policy support among college students. This study suggests that credibility is key for effective moral violations arguments of climate change.
Keywords: behavior; climate change; credibility; moral foundations theory; moral frame.