existential risk

noun2

1. •
   A risk which could destroy or permanently damage an entity; a risk to one's existence.

   • In an industry that relies more than anything on the appearance of total control, total safety, these two crashes pose as close to an existential risk as you can get. — 2019
2. •
   A hypothetical future event which could cause human extinction or permanently and severely curtail humanity's potential.

   • But perhaps the strongest reason for judging the total existential risk within the next few centuries to be significant is the extreme magnitude of the values at stake. — 2013