Are We Causing the Next Mass Extinction?

Tuesday, April 22, 2014

A school of manini fish pass over a coral reef at Hanauma Bay on January 15, 2005 in Honolulu, Hawaii. Many coral reefs are dying from water pollution. (Donald Miralle/Getty)

Forty-four years ago on April 22, 1970, demonstrations were set off around the country as Senator Gaylord Nelson established the first Earth Day. There was an outpouring of citizen concern, along with growing support from Congress, which led President Richard Nixon to sign an executive order that established the Environmental Protection Agency in December 1970.

Since then, environmental protection has become a political issue with deep partisanship on both sides—even as the most recent United Nations report on climate change warns of dire food shortages and other national security threats for countries across the globe.

See Also: U.N. Panel: Humans to Blame for Climate Change

Climate change has also diminished biodiversity, a problem with potentially serious consequences for every species.

Elizabeth Kolbert, staff writer for The New Yorker and author of "The Sixth Extinction: An Unnatural History," says we may be on the brink of another mass extinction. She defines mass extinction as a moment of time when the diversity on Earth, for one reason or another, plummets.

“Sixty-six million years ago, an asteroid plowed into planet earth and diversity on Earth plummeted,” she says. “That’s when we lost the dinosaurs among many other groups of organisms.”

There have been five mass extinctions throughout history, but Kolbert argues that the sixth mass extinction is different because it is being caused by humans.

“Right now unfortunately, extinction rates are very high, diversity is dropping very rapidly,” she says. “You sometimes hear scientists say that we are the asteroid in this context.”

When it comes to a mass extinction, entire ecosystems experience vast changes. Kolbert says we only know a tiny fraction of the species that occupy the planet, so it is difficult to understand how species truly interact. When the effects of taking a single organism out of an ecosystem are examined, however, Kolbert says massive effects and impacts can be seen.

“One of the groups that have been looked at most closely are large carnivores, which are really gone from most ecosystems, and those seem to have a very big cascading effect,” she says. “You get rid of those apex predators, and a lot of other things proliferate that then eat things; that then destroy habitats. So those effects really do ripple out through the landscape.”

All this may be happening too quickly—Kolbert says extinction is something that, over the course of the geological time spectrum, happens very rarely. According to her, one species of mammal should go extinct every several hundred years.

“If you’re a person who lives for 80 years, you should never see a mammal go extinct,” she says. “Now, we all know of mammals that have either gone extinct in our lifetime or are on the very, very edge of extinction. Unfortunately, in all of these extinctions we are a causal agent.”

Hawaii, which has been called “the extinction capital of the world,” is an interesting case in the study of extinction, says Kolbert. Since it was so isolated, its species were able to develop and thrive—until humans arrived.

“It's one of the most isolated places on the planet so one of the great mysteries on some level is how anything got there," says Kolbert. "Yet it did—it has wonderful birds, great flora and unique snails that you can find only in Hawaii. Animals mated, they radiated out, and they formed new species. It was missing many groups of animals like land mammals."

While the isolated chain of islands is still uniquely beautiful, Kolbert says that the arrival of other mammals—humans—disrupted the unique ecosystem in Hawaii.

"When people arrived and they brought rats and pigs and things like that, it really devastated the ecosystem,” she says. “That has just continued. We’ve brought more and more non-native species over and the native species were unprepared to deal with that.”

What will it take for people to stop seeing threatened species as statistics or small events in the course of history? Kolbert isn’t sure, but she says that time is running out. She says she was fortunate enough to spend time with the endangered Sumatran rhino, but not everyone will have that opportunity.

“If the future of the planet depends on everybody looking into the eyes of a Sumatran rhino then I’m afraid we’re in trouble, there are just too few of them left,” she says.

If things keep continuing on this path, Kolbert says our planet could look very different in the future.

“What’s happening right now is going to leave a mark that is, for all intents and purposes, permanent,” she says.

She says 100 million years from now, geologists will not only be able to see that many organisms went extinct, but they’ll also see the role we played in that extinction.

“We’re gonna see this huge emission of carbon, the carbon dioxide that we’re putting up into the air by burning coal and oil and natural gas,” she says. “That also leaves a record in the rock record.”

Guests:

Elizabeth Kolbert

Editors:

T.J. Raphael

Comments [8]

Keri from NJ

Invasion of non-native species (plant life, aquatic animals, mammals including humans. As for humans, this frankly makes the strongest argument against immigration reform for it shifts the demographic as well as the economy and necessarily for the overall benefit of the native species.

May. 14 2014 09:04 AM
Markie from Ohio

You Mr Hockenberry should be ashamed for your sloppy journalism in not querying Ms Kolbert's about the validity of her assertions.
1. The Sixth Extinction.: We know of Five Great Extinctions. For there to be a Sixth; some 90% or so of all species would have to cataclysmically disappear. Short of a massive nuclear holocaust, nothing man will do would result in such. No matter have ravages man reigns on biodiversity it will never approach such a parameter.
2. There is nothing of an "Unnatural History" as to what a clever species such as Homo sapiens does. In our galactic neighborhood or in this galaxy, let alone this universe: similar events have been played out before or will be played out in the future. Any species that evolves to the point where it can manipulate organic or inorganic chemistry: it will inevitably bend the dynamic forces of evolution in its favor for varying periods of time. But alas, it is a basic tenet of Ecology that all monocultures eventually collapse.
So the bottom line is: How clever are we really and what will we have to do live to in Paradise. Sad to say the Damage already done to Paradise is great, but repairable, give or take a couple of million years.
Oh silly me, no one thinks that far ahead.

Apr. 28 2014 10:42 PM
ML from Miami FL

Saving the environment is a matter of economics and nothing else. Don't cry about the death of this planet and rejoice about the continuance of the status quo. Everyone reading this can find solace that they will die before any serious man-made ecological calamity occurs. For those of you with kids and grand kids, be content that you won't have to see them suffer.

Apr. 23 2014 11:35 AM
Ed from Larchmont

The review of Ms. Kolbert's book in Harper's pointed out that the science is all good, accurate. But the reviewer described the metaphysics, the worldview of the book, which he agreed with, and took for granted, but which is very flawed: that man is one animal among many, a materialist view, the Darwinian view. This view of man is just not correct.

As Chesterton said, modern philosophies lead to despair and self-destruction if carried to their logical conclusions, and this is true of Darwinism. (The science is right, just not the materialist metaphysics, Darwin was angry because his beloved daughter died -Anna?- and dropped his Anglican faith, whatever he did have.) If we didn't know that Darwinism was a hopeless philosophy before, the global environmental disaster makes it clear: if the physical world is our only hope, we have no hope.

But man is not this rapacious creature, certainly not by nature. Man sinned, and became disordered, and so does destructive things. But God told man 'Be fruitful, multiply, and subdue the earth', the earth is made for man, so to say we're wrong to have children and to live goes directly against God's intention. Of course we need to be good stewards (see Pope Benedict and Pope Francis' recent encyclicals which speak of the environment). But man is flawed, because of sin, but good.

Apr. 23 2014 08:31 AM
Taher from Croton on Hudson NY

Mass extinction of spices means a radical change in the global
and local environments . Since we humans are part of that Eco system
who is to say we too will not be part of mass extrication
sooner rather then later.

Apr. 22 2014 03:53 PM
Markie from ohio

It is always sad to hear a so called scientific journalist bastardize the pronunciation of Ecosystem, But then again, I suppose she would prefer that the science of Ecology be pronunced ECHOlogy.

Apr. 22 2014 03:05 PM
CAROLINE from NJ/USA

You betcha we are - most certainly causing another mass extinction. To bad it's not going to be ourselves (humans) extinction. It would be lovely to start over.

Maybe next time around humans would evolve from some more-like Bonobos. (If you don't know of them - check 'em out cause they truly, make love not war.)

Eventually, the earth would be over populated as it is, and growing more-so, but perhaps the evolutionary path would lend less to warring and religious, and all things divisive and derisive. Those humans might work together to save the earth - and hey! We would have left behind all our buildings - oh shoot! This is much-to-much out of control, so we'll just have to wait and see if we can burn up the planet so all can start again. It's going to be painful, but it's going to happen.

Apr. 22 2014 12:10 PM
Ed from Larchmont

Ms. Kolbert gives us a new context for the six days of creation: like an artist painting a canvas and then clearing it off and going in another direction. The six mass extinctions. Perhaps, in spite of ourselves, we have obeyed the command 'Go and fill the earth'.

Apr. 22 2014 09:17 AM

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