Ecocide, or perhaps biocide, or perhaps omnicide, would be an act exterminating not just all humans, but the entire circle of life on planet earth itself.
Tad Daley: Apollo or Extinction
We must act in our own self-defense “immediately, before humankind exterminates itself in an act of nuclear omnicide.”
Francis A. Boyle’s “Protesting Power – War, Resistance and Law”
The word ‘omnicide’ is a formed from ‘omni-‘ (‘all’) + ‘-cide’ (kill).