Search for: All records

Abstract Extreme heat events are one of the deadliest weather-related hazards in the United States and are increasing in frequency and severity as a result of anthropogenic greenhouse gas emissions. Further, some subpopulations may be more vulnerable than others because of social, economic, and political factors that create disparities in hazard impacts and responses. Vulnerability is also affected by risk perceptions, which can influence protective behaviors. In this study, we use national survey data to investigate the association of key sociodemographic factors with public risk perceptions of heatwaves. We find that risk perceptions are most associated with income, race/ethnicity, gender, and disability status. Age, an important predictor of heat mortality, had smaller associations with heat risk perceptions. Low-income, nonwhite, and disabled individuals tend to perceive themselves to be at greater risks from heatwaves than other subpopulations, corresponding to their elevated risk. Men have lower risk perceptions than women despite their higher mortality and morbidity from heat. This study helps to identify subpopulations in the United States who see themselves as at risk from extreme heat and can inform heat risk communication and other risk reduction practices. 

Abstract Message diffusion and message persuasion are two important aspects of success for official risk messages about hazards. Message diffusion enables more people to receive lifesaving messages, and message persuasion motivates them to take protective actions. This study helps to identify win-win message strategies by investigating how an under-examined factor, message content that is theoretically important to message persuasion, influences message diffusion for official risk messages about heat hazards on Twitter. Using multilevel negative binomial regression models, the respective and cumulative effects of four persuasive message factors, hazard intensity, health risk susceptibility, health impact , and response instruction on retweet counts were analyzed using a dataset of heat-related tweets issued by U.S. National Weather Service accounts. Two subsets of heat-related tweets were also analyzed: 1) heat warning tweets about current or anticipated extreme heat events and 2) tweets about non-extreme heat events. This study found that heat-related tweets that mentioned more types of persuasive message factors were retweeted more frequently, and so were two subtypes of heat-related tweets. Mentions of hazard intensity also consistently predicted increased retweet counts. Mentions of health impacts positively influenced message diffusion for heat-related tweets and tweets about non-extreme heat events. Mentions of health risk susceptibility and response instructions positively predicted retweet counts for tweets about non-extreme heat events and tweets about official extreme heat warnings respectively. In the context of natural hazards, this research informs practitioners with evidence-based message strategies to increase message diffusion on social media. Such strategies also have the potential to improve message persuasion.