The Seas Could Turn to Sulfur

Question: What non-greenhouse extinction events have happened in the past, and are they likely to recur?

\r\n

Peter Ward: Well, we certainly know that we were hit 65 million years ago by a very large rock from space, Hollywood knows this with the two blockbusters, “Armageddon” and “Deep Impact,” so it must be true. It was really interesting, in ’95, Spielberg sent his minions to a conference to where a number of us were attending about this particular hit and indeed, there is a great danger out there. We are surrounded by asteroids, some become berth crossing. Jupiter has a way of perturbing comets and sending them from stable orbits to earth-crossing orbits. We will get hit again. How big the hit will be is only a matter of time until we get something the same size that killed off the dinosaurs, should humanity last long enough that is. But that size hit looks like only once every 100 million years, or more. We haven’t had a hit that size for the last 500 million years. So, it does look like it is a rare event to have something that big; a 10 kilometer asteroid hit us.

\r\n

Question: Given the low number of extinction events in recent Earth history, are we “due” for another?

\r\n

Peter Ward: Well, no, it’s just the whole sense of when is it going to happen again and it appears that most of the big mass extinctions have been caused by these nasty volcanic events. The last one didn’t cause a mass extinction. It was in the Tertiary Period. This was in my own home state, Washington State, the Columbia River Basalts. Out came all this basalt, as liquid lava, and a lot of the carbon dioxide came out too, but not enough to cause the earth to go into a really nasty mass extinction. The mass extinctions caused by the basalts again, are simply by heating the world. Now when you heat the world you heat the pole more than you do the equatorial region. When that happens, you start losing circulation. The only reason you have wind now is you have a hot spot and a cold spot and they’re trying to equilibrate. Well, an ocean current you have the same thing. You have a cold Antarctic and then you warm them up, the ocean circulation system is dampened down; there’s much less heat difference.

\r\n

So when we heated the poles to the point that there is no longer – or already in a very sluggish ocean circulation, the ocean is going oxic, they lose their oxygen. They only keep oxygenated now because of this vigorous mixing. Well, even when you have oxygen in the atmosphere and contact with the surface, once you slow down any circulation, that whole basin can lose this oxygen. The Black Sea is the same case. It’s sits under a 21% oxygen atmosphere, and yet the Black Sea, except for the top several meters, in anoxic. It’s black because it’s producing a lot of sulfur-producing bacteria and there’s very nasty gasses that are produced.

\r\n

We now think the big mass extinctions were caused by global anoxia. The oceans themselves so sluggish that the hydrogen sulfide bacteria are produced in huge areas of the ocean bottom bubbles up to the surface and starts killing things; rotten egg killing. It would be extremely nasty. Hydrogen Sulfide poisoning is a horrible death. Two hundred hydrogen sulfide molecules among a million air molecules is enough to kill a human. I mean, just breathing in 200 of those little things amid all the million you’re got in oxygen and boom, you’re down, horribly down.

\r\n

So, this is a really nasty poison and it was certainly present in past oceans during these short-term global warming events. That’s why it’s really spooky what we’re doing now.

Recorded on January 11, 2010
Interviewed\r\n by Austin Allen

From asteroids to worldwide hydrogen sulfide poisoning, extinction expert Peter Ward offers a diverse menu of scenarios for humanity’s demise.

Why Elon Musk doesn't like Jeff Bezos's space colonies

Elon Musk took issue with recent ideas for space exploration from Jeff Bezos.

Getty Images
Technology & Innovation
  • Elon Musk and Jeff Bezos have sparred over space exploration previously.
  • Musk wants to focus on Mars while Bezos has the moon and space colonies as goals.
  • In a recent tweet, Musk called out Bezos's plans for space colonies as unrealistic.
Keep reading Show less

10 new things we’ve learned about death

If you don't want to know anything about your death, consider this your spoiler warning.

Culture & Religion
  • For centuries cultures have personified death to give this terrifying mystery a familiar face.
  • Modern science has demystified death by divulging its biological processes, yet many questions remain.
  • Studying death is not meant to be a morbid reminder of a cruel fate, but a way to improve the lives of the living.
Keep reading Show less
Big Think Edge
  • Push Past Negative Self-Talk: Give Yourself the Proper Fuel to Attack the World, with David Goggins, Former NAVY SealIf you've ever spent 5 minutes trying to meditate, you know something most people don't realize: that our minds are filled, much of the time, with negative nonsense. Messaging from TV, from the news, from advertising, and from difficult daily interactions pulls us mentally in every direction, insisting that we focus on or worry about this or that. To start from a place of strength and stability, you need to quiet your mind and gain control. For former NAVY Seal David Goggins, this begins with recognizing all the negative self-messaging and committing to quieting the mind. It continues with replacing the negative thoughts with positive ones.