Sure, of course. But suppose you're standing on the precipice of WW2 or the Black Plague and you can clearly see them coming, even if there's some uncertainty about when, and what exactly will happen. Wouldn't you try to prevent them?

Historically, people always have, and sometimes they've succeeded. The Cuban Missile Crisis is maybe a good example of this. During that era, there was a widespread feeling that we were dangerously close to nuclear war. Surely that sense of danger was a critical part of the reason cooler heads prevailed in the end.