The US public consistently ranks climate change as a low national priority due, in part, to a lack of personal engagement and a sense of temporal and spatial distance from the environmental effects (Leiserowitz 2006). Yet, the chief method for climate change mitigation, the reduction of fossil fuel use, would also reduce particulate air pollution, which is implicated in over three million deaths worldwide each year (Lim et al. 2013). Indeed, in the US, improved public health ranks among the top perceived benefits of reducing fossil fuel use (Leiserowitz et al. 2013), and the scientific community has been promoting these benefits-such as reduction in hospitalizations and premature deaths -for over a decade (Cifuentes et al. 2001; West et al. 2013). Furthermore, the health behavior literature demonstrates that personal perception of risk, which is likely to be linked to health, is one of the strongest motivators of behavioral change (Few 2007; Maibach and Parrott 1995). Thus, one possible method for garnering support for carbon emissions reduction is to emphasize the added co-benefit of reducing present-day, health-related impacts. However, it remains to be understood whether public health messaging can lead to improved climate change mitigation efforts, or how specific segments of the US population will respond to this message. In particular, emphasizing health co-benefits may be a strong motivator of attitude change among individuals who are less concerned about environmental threats or who deny the existence of anthropogenic climate change.