If a Global Catastrophic Biological Risk Materializes, at What Stage Will We Recognize It?

G lobal catastrophic biological risks (GCBRs) do not come with warning labels declaring them as such. Admittedly, if smallpox virus were released at multiple points around the world simultaneously, or if whole cities started showing major upticks in mortality from a respiratory infection, the global community would have a clear indication that a catastrophic event was occurring and would react accordingly. But there are many other scenarios-perhaps more likely in the aggregate-in which the early stages of a globally catastrophic biological event (GCBE) are much harder to identify as such (I distinguish event from risk in the sense that a risk is a possibility something will happen, and an event is when that thing actually happens). Put another way: If in the next 50 years there is a single biological event that kills 100 million people, there is a good chance the magnitude of that event will not be recognized from the start. For concreteness, this brief comment will focus on infectious diseases of humans.