Perception of Risk Posed by Extreme Events

Extreme events, by definition, cause much harm to people, property, and the natural world. Sometimes they result from the vagaries of nature, as in the case of flood, earthquake, or storm, and thus are truly the outcomes of games against nature. In other cases they follow technological failure or unintentional human error, as in the case of Chernobyl or Bhopal, putting them also into the category of risks that are predictable only probabilistically. More recently we have witnessed another form of extreme hazard, resulting from terrorism. One of us has termed this a new species of trouble (Slovic, in press), since it involves an intelligent and motivated opponent, putting the situations that give rise to these types of extreme events into the domain of economic game theory. The purpose of this brief review is to examine what existing research can tell us about the perception of risk associated with these extreme events. We will also point out issues that remain in need of exploration.