the.com/sixth extinction

means A term for the current, human-caused wave of species loss and ecological collapse happening on Earth right now, severe enough to rank alongside the five great mass extinctions of the deep past.

from The phrase borrows its structure from geology's established count: paleontologists identify five confirmed mass extinctions in the fossil record, from the end-Ordovician die-off to the asteroid that ended the dinosaurs. 'Sixth extinction' entered wider circulation through late-20th-century scientific writing and was cemented in public imagination by Elizabeth Kolbert's 2014 book of that title, which argued humanity's effects on climate, habitats, and other species constitute a new entry in that grim ledger — this time driven not by rock from space but by one species rearranging the planet.