Debate Persists Over Whether Earth Faces a Sixth Mass Extinction

The scientific community remains divided on whether Earth is currently undergoing a sixth mass extinction. A new study, published in PLOS Biology, analyzed extinction data from the International Union for Conservation of Nature (IUCN) covering more than 163,000 species and 22,000 genera over the past five centuries. The findings show that fewer than 2% of mammal genera have gone extinct, and the genus-level extinction rate across all species groups remains below 0.5%—far lower than the 75% species-loss threshold typically used to define a mass extinction event.

The study highlights that extinctions have been taxonomically and geographically concentrated: most extinct genera were mammals and birds, with about 75% being island endemics. Moreover, extinction rates have declined markedly since the early 20th century, suggesting that earlier human activities such as island colonization drove historical losses, but this does not necessarily signal an imminent large-scale extinction.

Other researchers, however, caution against underestimating the crisis. Teams from Stanford University and the National Autonomous University of Mexico argue that focusing only on final species extinctions overlooks catastrophic ecological disruptions caused by rapid population collapses—such as the global decline of insects—which threaten ecosystem function and human survival. Scholars from Arizona State University further stress the importance of balancing scientific accuracy with public trust when communicating the urgency of biodiversity loss.