Paleobiologist Discusses Sixth Extinction

Associate Professor of Geological Sciences and Paleobiologist at Stanford University Jonathan Payne visited Colgate on Tuesday, March 22 to educate students and faculty on the Sixth Extinction, which is an ongoing extinction event mainly caused by human activity.

Payne’s presentation, titled “The Emerging Mass Extinction in World Oceans,” combined studies from his peers with his own research to show that our generation is in the midst of a sixth mass extinction. Further, he used his data to explain that the extinction arose as a result of human interaction with the environment.

So far, only the effects of hunting, which began causing extinctions as long as 12,000 years ago, have been felt, as the estimated current extinction rate is anywhere between 100 and 1,000 times the typical extinction rate.  

Junior geology concentrator Oleg Kozel provided some insight on what he believes to be the Sixth Extinction.

“The [current] extinction concerns economic extinction, rather than climate change or more ecologically destructive processes,” Kozel said.

By researching fossil records in Turkey, Italy and China, as well as comparing his findings with the previous mass extinctions, Payne concluded that mostly large animals have been going extinct.

“What we see in the modern [extinction] is that body size is what’s associated with extinction risk, and big animals going extinct is probably not a climate warming signal or an ocean acidification signal, it is a hunting and fishing signal,” Payne said.

Largely caused by the release of carbon dioxide from human activity, the “deadly trio” that Payne detailed during his presentation – global warming, ocean acidification and ocean deoxygenation – remains a looming threat for the earth’s future.

Although scientists can currently observe ocean acidification – specifically in its effects on corals – the process should speed up in the coming years as global temperature increases and the ocean continues to circulate.

“Each year, we burn more fossil fuels than we did the year before. So we’re still headed toward more effects of ocean acidification. If you think that corals can’t live in waters that are [acidic], within the coming centuries, there can be very little of the ocean that is coral habitat anymore,” Payne said.

According to Payne, even if humans can do little to reverse the ensuing effects of climate change and carbon dioxide emissions, humankind can still enact policy changes to curb hunting, at the very least. He cited recent successful efforts to halt whaling, which resulted in the repopulation of some whale species.

“When we make targeted efforts to preserve individual species, they often work,” Payne said.

One of the most concerning aspects of the modern extinction is that there are no biological analogues to compare it to. Although scientists have measured the effects of ocean acidification and ocean deoxygenation in previous mass extinctions, there are no data to show.

“There have been no ecological changes in the geological past that look like the ones we’re inflicting right now,” Payne said. “To me, that’s a message that we have to be very careful. We really don’t know what we’re getting ourselves into.”