How Americans Respond to Information About Global Warming's Health Impacts: Evidence From a National Survey Experiment.

Americans tend to see global warming as a distant threat, but a small body of previous research suggests that information about the health implications of global warming may enhance public engagement with the issue. We sought to extend those findings with a longitudinal study that examined how Americans react to information about eight specific categories of health impacts from global warming. In winter 2017, we conducted a two-wave survey experiment using a quota sample of American adults (n = 2,254). Participants were randomly assigned to a treatment group who read eight brief essays about different categories of health impacts from global warming or to a control group who received no information. Participants answered questions before reading the essays, immediately after reading each essay and at the conclusion of all essays (treatment participants only), and 2-3 weeks later. Reading the information had small- to medium-sized effects on multiple indicators of participants' cognitive and affective engagement with global warming, especially among people who are politically moderate and somewhat conservative; some of these changes persisted 2-3 weeks later. Some impacts were seen as more novel and worrisome, including illnesses from contaminated food, water, and disease-carrying organisms. Our findings provide the most definitive evidence to date about the importance of raising awareness about the health impacts of global warming. While participants believed all of the essays as offered valuable information, educational efforts might most productively focus on impacts that are relatively less familiar and more emotionally engaging, such as food-, water-, and vector-borne illnesses.