(On your definition it seems likely that there won’t ever again be a warning shot for any existential risk.)
The only risk I can think of that might meet the post’s definition is an asteroid that has to be (successfully) diverted from colliding with the Earth.
But I think you might be right in that even that wouldn’t convince “50% of currently-skeptical people [to] change their mind”.
The only risk I can think of that might meet the post’s definition is an asteroid that has to be (successfully) diverted from colliding with the Earth.
But I think you might be right in that even that wouldn’t convince “50% of currently-skeptical people [to] change their mind”.