Everything we know and love will one day be reduced to a thin strip of sediment. That’s strangely comforting.

The Long (Long) View

interview by Heather Shayne Blakeslee

Elizabeth Kolbert’s book “The Sixth Extinction: An Unnatural History” is a great read for anyone who is in need of a little perspective about our place as humans on an ever-changing planet. It was 1705 when the first mastodon tooth was discovered in America; in short order, we had a new understanding of the world that included the process of evolution. It was 1980 when we figured out what killed the dinosaurs.

Kolbert is interested in the next major die-out—which will likely include the species Homo sapiens—and what record humans will leave behind. 

It seems sort of incredible that we’ve learned so much about the world in the last 200 years, and also that we’ve done so much to alter it, although our entire history as a species is still a blip on the geological clock. Did researching this book alter your perception at all of time or agency, or of mortality? 
EK: Yes. You know, we’re all bounded by our limited experience and our imagination, but I think we tend to live so much in the here and now, and so much in the last week, last month, even 24 hours. Try to step back— imaginatively, since that’s the only way you can do it—and really hang out with people who can look at a mountain and tell you how it formed 500 million years ago. 

I’m looking right now out of my window at mountains that are half a billion years old, basically, and they were much, much higher at one point. It does put things in a somewhat different perspective. It was alarming to realize that what [humans] are doing is actually quite unusual, even in the biggest time scale you could look at. But it will be erased one day.

What are some of the ways in which humans have changed the planet?
EK: Obviously the world will continue to rumble on…  [But] we’ve changed the carbon content of the atmosphere; that will be recorded in geological history… recorded in the rocks…

We dammed up a lot of rivers—changed their course… we have a more or less permanent geological record… we’ve mowed down big tracks of forests and planted corn or soy that will also leave traces behind…. In a mass-extinction event, that will be a tremendous record. … Geologists [interpret] things a bit differently from you and me. They’re asking what of these changes are permanent. And that’s actually the question that’s absorbing geologists right now: What is it that we’re going to be able to look at and is going to be synchronous with a signal around the world?… One possibility, another way we’ve changed the planet, more or less permanently, is with nuclear testing. We’ve left behind certain radioactive nucleotype that will be around for a very, very long time.

Do you feel like you have a much different understanding of that picture—of a mass extinction event happening—before and after the book?
EK: People much more expert than I have done numerical analysis and concluded that if we are not in the middle of a mass extinction, we are poised for one, and one could unfold with amazing rapidity given the rate at which things are disappearing. So, when I went into this it wasn’t quite a wide-eyed, “Oh, I wonder if something is going on.” It was definitely with the idea that something big is going on.
One point that I hope comes through in this book is: We’ve become so inured to extinction, so the idea that something is going extinct just doesn’t strike us as a particularly big deal.
But if you, in a human lifetime, are seeing multiple species go extinct, that is huge. That already suggests something very, very unusual is going on, because species can last quite a long time.

You spend a great deal of time with various scientists and species-specific advocates in this book. One that you begin with is a steward of the Panamanian golden frog, and he says to you, “Each one is as important to me as an elephant.” It struck me when I read that, because it was really getting at the fact that the species that get the most attention from the general public are sometimes the ones that inspire the most awe in us—like the elephant. But when it comes to life and death of bacteria or fungi and other kinds of species, those are the ones that are probably going to write our history.
EK: Even though we are in awe of the elephants—at least in theory—and we love elephants—once again, in theory—I would say to a certain extent that elephants are in terrible trouble right now, even as we speak. There’s a real crisis for African elephants, and Asian elephants are already decimated. So even though we, quote unquote, pay more attention to charismatic fauna—big mammals—actually, big mammals are in terrible trouble. 
The great apes are all in terrible trouble. So we may feel some affection for them, and we see them in zoos, but those few that remain in the wild are really, really in trouble. I can’t stress that enough—our very close relatives.
That being said, I think it’s [biologist E.O. Wilson] who makes the point, if we got rid of all of the mammals on the planet, the planet would still chug along—certainly if we got rid of all the people the planet would chug along very, very nicely. But if you suddenly got rid of all the bacteria—everything responsible for decay and recycling and soil production—life as we know it would come to an end very, very quickly. Immediately. I think it’s another Ed Wilson thing: “It’s the little things that rule the world.” And that’s really true.

When it comes to our responsibility for climate change, one of the things that gets talked about most often is carbon in the atmosphere. Why is the much-less-talked-about acidification of the oceans an equal threat to life on the planet?
EK: Well, first of all, the oceans are just very, very big. You know, they cover 70 percent of the planet, roughly, as every school kid learns. And it’s actually very different to change the chemistry of the ocean, since they have a very large buffering capacity, so the chemistry doesn’t change easily, but we’re exhausting that buffering capacity. We are changing the chemistry of the oceans—that’s not debatable, that’s measurable. It’s [also] very unusual in the history of life or the chemistry of the oceans. In terms of human life and other forms of life, ocean acidification is quite possibly a bigger threat than climate change.

At one point, you quote a biologist who says of an invasive species, “While it’s easy to demonize the brown tree snake, the animal is not evil, it’s just amoral and in the wrong place, precisely what Homo sapiens has done all over the planet, succeeding extravagantly at the expense of other species.” Did that idea of humans being an amoral part of the animal kingdom settle in for you more deeply as you researched the book?
EK: I think the question of “What is the human?” ultimately is the question at the center of the book. The subtitle is “An Unnatural History,” and some people have told me it should have been “A Natural History,” and that’s reasonable, too. 
I think the question of why is it that we turn out to be so destructive to other species—that I don’t think is debatable, really, that we have the peculiar ability and propensity to do in our fellow creatures on the planet. Why does this turn out to be, and how does this relate to us as biological beings and us as ethical actors? And is all of our talk of ethics really just a lot of talk?

You write in the book, “One hundred million years from now, all that we consider the great works of man, the sculptures and the libraries, the monuments and the museums, the cities and the factories, will be compressed into a layer of sediment not much thicker than a cigare
tte paper.” Do you believe there’s anything that might alter that path, or is that just the way of the planet?
EK: That is just the way of the planet. Erosion and sedimentation—and the pressure of gravity.

Elizabeth Kolbert is the author of the Pulitzer-Prize winning book “The Sixth Extinction: An Unnatural History” and is a staff writer for The New Yorker.