Scientists warn that Earth is on the brink of sixth mass extinction
“Earth’s warming climate is contributing to an infection responsible
for tropical frog extinctions.
Credit: Nicolle Rager Fuller, National Science Foundation
Due to the projected steep and rapid decline of many animal species, say biologists at the University of California at Berkeley, Earth appears to be on the brink of a massive die-off, following the same patterns as five massive extinctions that have occurred in the past 540 million years.
“If you look only at the critically endangered mammals–those where the risk of extinction is at least 50 percent within three of their generations–and assume that their time will run out and they will be extinct in 1,000 years, that puts us clearly outside any range of normal and tells us that we are moving into the mass extinction realm,” said Anthony Barnosky, an integrative biologist, curator in the university’s Museum of Paleontology and research paleontologist in its Museum of Vertebrate Zoology, and first author of the paper published in the journal Nature.
“A modern global mass extinction is a largely unaddressed hazard of climate change and human activities,” said H. Richard Lane, program director in the National Science Foundation’s (NSF) Division of Earth Sciences, which funded the research.
“Its continued progression, as this paper shows, could result in unforeseen–and irreversible–consequences to the environment and to humanity,” said Lane.
According to Barnosky, if already threatened species – specifically, those officially labeled critically endangered, endangered, and vulnerable – continue toward the path of extinction, Earth could experience the beginning of the massive die-off in as little as 3 to 22 centuries.
If habitat fragmentation, invasive species, disease and global warming were effectively dealt with, the Earth’s threatened species could be saved to the point of avoiding the crisis.
“Our findings highlight how essential it is to save critically endangered, endangered and vulnerable species,” Barnosky said.
“With them, Earth’s biodiversity remains in pretty good shape compared to the long-term biodiversity baseline.
“If most of them die, even if their disappearance is stretched out over the next 1,000 years, the sixth mass extinction will have arrived.”
