Advocacy messages about climate and health are more effective when they include information about risks, solutions, and a normative appeal: Evidence from a conjoint experiment

Previous research has shown that providing information about the health consequences of climate change can increase climate change issue engagement and support for mitigation policies. Here, we extend that research by testing the motivational value of three categories of climate information (termed information categories): health consequences of climate change; health benefits of climate solutions; and calls-to-action intended to motivate people to engage in political advocacy for climate solutions. The use of choice-based conjoint analysis enabled us to determine the effectiveness of each information category, as well the effectiveness of specific types of information within each category. Research participants were adults quota-sampled to represent the U.S. population (n=7,596). We found that each of these categories–consequences, solutions, and a call-to-action–enhanced the overall motivational value of the message, with solution information being the most influential. Of the 360 message combinations tested, the most compelling first described the negative impacts of climate change on air quality, then explained how transitioning to clean energy will benefit people's health, and ended by explaining that most Americans support this solution, and many are taking action to advocate for it. These findings are consistent with a large body of risk communication theory, and provide practical insights to health professionals and others seeking to build public and political will for actions that reduce the health threats posed by climate change.