A warning shot is a global catastrophe that increases awareness and concern about similar future risks and thus reduces the probability of an existential catastrophe.

Terminology

The expression warning sign is sometimes used to describe any event that increases awareness and concern about a particular category of existential risk, regardless of whether the event itself constitutes a global catastrophe. For example, plausible candidates for an AI safety warning sign include not only a catastrophic failure by an AI system but also public outreach campaigns or the publication of an exceptionally persuasive book on AI safety.^[1] However, sometimes the expression "warning shot" is itself used in this expansive sense.^[2]