In a media landscape saturated with sensational science stories and "end of the world" Hollywood productions, it may be hard to persuade the wide public that real catastrophes could arise as unexpectedly as the 2008 financial crisis, and have a far greater impact.
Society could be dealt shattering blows by the misapplication of technologies that exist already or could emerge within the coming decades. Some of the scenarios that have been envisaged may indeed be science fiction, but others may be disquietingly real. I believe these "existential risks" deserve more serious study. Those fortunate enough to live in the developed world fret too much about minor hazards of everyday life: improbable air crashes, possible carcinogens in food, low radiation doses, and so forth. But we should be more concerned about events that have not yet happened but which, if they occurred even once, could cause worldwide devastation.