Extinction Level Event

An Extinction Level Event (ELE or mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth or the home planet of a species. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the rate of speciation.

Extinction is generally a Type 0 and Type I concern; however higher types may be almost fully eradicated by enemies.

As a Type II civilization expands aggressively using FTL and sprawls far beyond its government, it may regress into societal collapse and eventually a form of interstellar barbarism with little regard for life. Eventually each faction may adopt its own government and culture and evolve into a new species, leaving its origins long forgotten and effectively extinct.

Type III and beyond will have found instantaneous travel and spacetime manipulation, and so the problems of sprawl and uncontrolled government may be a thing of the past. They could become sophonts, be part of benevolent and civilized galactic or universal associations, and eventually ascend into higher level beings, effectively making their original species extinct.

Non-anthropogenic ELEs:
Planetary management and respecting planetary boundaries have been proposed as approaches to preventing ecological catastrophes. Within the scope of these approaches, the field of geoengineering encompasses the deliberate large-scale engineering and manipulation of the planetary environment to combat or counteract anthropogenic changes in atmospheric chemistry. Space colonization is a proposed alternative to improve the odds of surviving an extinction scenario. Solutions of this scope may require megascale engineering.