Considering that we’re in the midst of the Anthropocene mass extinction event already, I’d say it would be a certainty. The only question would be how bad it would get. Given how much larger that crater would be than Chicxulub, I’m guessing it would exceed the “Great Dying” (Permian-Triassic extinction event) to take the crown.
Edit: The Wilkes Land Crater in Antarctica, which may be associated with the Great Dying, was “only” a little over 2.5 times larger in diameter than Chicxulub and thus still way smaller than the crater depicted. That said, I guess a nuclear crater wouldn’t be associated with a flood basalt “exit wound” at the antipode the way an impact crater might be, so maybe it wouldn’t be comparable.
Considering that we’re in the midst of the Anthropocene mass extinction event already, I’d say it would be a certainty. The only question would be how bad it would get. Given how much larger that crater would be than Chicxulub, I’m guessing it would exceed the “Great Dying” (Permian-Triassic extinction event) to take the crown.
Edit: The Wilkes Land Crater in Antarctica, which may be associated with the Great Dying, was “only” a little over 2.5 times larger in diameter than Chicxulub and thus still way smaller than the crater depicted. That said, I guess a nuclear crater wouldn’t be associated with a flood basalt “exit wound” at the antipode the way an impact crater might be, so maybe it wouldn’t be comparable.