Runaway Global Warming 635 Million Years Ago

LiveScience.com on Yahoo ^ | 5/28/08

[NormsRevenge]

A sudden and extreme case of runaway global warming 635 million years ago was caused by an abrupt release of methane, a powerful greenhouse gas, scientists said today.

The methane seeped from ice sheets that covered much of the planet toward the end of a frigid era called Snowball Earth. The gas escaped gradually at first and then very quickly from clathrates, or methane ice that forms and stabilizes beneath water ice sheets. As the water ice melted, pressure was relieved on the clathrates and they began to de-gas.

The transition represents one of the earliest known cases of what scientists now call a climatic tipping-point.

The big question scientists are now pondering: Could it happen again?

"Our findings document an abrupt and catastrophic global warming that led from a very cold, seemingly stable climate state to a very warm, also stable, climate state - with no pause in between," said geologist Martin Kennedy of the University of California at Riverside, who led the research team.

"What we now need to know is the sensitivity of the trigger," Kennedy said. "How much forcing does it take to move from one stable state to the other - and are we approaching something like that today with current carbon dioxide warming?"

Also called marsh gas, methane is a colorless, odorless gas. As a greenhouse gas, it is about 30 times more potent than carbon dioxide.

Methane clathrates still exist in Arctic permafrost and beneath the oceans at continental margins. Kennedy said it's possible that very little warming could unleash this trapped methane, potentially warming the planet by tens of degrees.

Kennedy and colleagues collected hundreds of marine sediment samples in South Australia for stable isotope analysis, an important tool used in climate reconstruction. They found the broadest range of oxygen isotopic variation ever reported from marine sediments, which they attribute to melting waters in ice sheets as well as destabilization of clathrates by glacial meltwater.

"Today we're conducting a global-scale experiment with Earth's climate system," Kennedy said, "and witnessing an unprecedented rate of warming, all with little or no knowledge of what instabilities lurk in the climate system and how they can influence life on Earth."

He said Nature did a similar experiment 635 million years ago, "and the outcome is preserved in the geologic record. We see that strong forcing on the climate, not unlike the current carbon dioxide forcing, results in the activation of latent controls in the climate system that, once initiated, change climate to a completely different state."

The research, detailed in the May 29 issue of the journal Nature, was supported by the National Science Foundation and NASA's Exobiology Program.

[NormsRevenge]

Could it happen again?

"Our findings document an abrupt and catastrophic global warming that led from a very cold, seemingly stable climate state to a very warm, also stable, climate state - with no pause in between," said geologist Martin Kennedy of the University of California at Riverside, who led the research team.

"What we now need to know is the sensitivity of the trigger," Kennedy said. "How much forcing does it take to move from one stable state to the other - and are we approaching something like that today with current carbon dioxide warming?"

[Texas Eagle]

What caused the earth to be covered with ice in the first place? Was it the meteor that hit the earth and filled the atmosphere with so much dust that it killed of the dinosaurs?

If so, maybe that means the earth is just returning to its pre-meteor climate conditions.

[MadMax, the Grinning Reaper]

Methane also comes from bull-sh*t, much like some of the gobbydeegook in this article.

Heck, if this scientist were to give a hour long speech, we’d have more global warming than Mt. St. Helen’s caused with its hot gases.

As Helen Thomas liked to say, “Blame it on the cows. Blame it on the cows.”

[writer33]

We’re doomed, NR. We’re doomed!

:-)

[devere]

Al Gore was there and caught it on film!

[JaneNC]

Shooooo

What nonsense

[RobinOfKingston]

... pressure was relieved on the clathrates and they began to de-gas.

Dang, I gotta remember that for next time.

[hellbender]

Why wasn’t there a similar “runaway warming” accompanying the retreat of the Pleistocene ice sheets? Did the author consider that the composition of the atmosphere 635 million years ago was different from that of today (for example, the oxygen level was much lower)?

[SoldierDad]

Is the sky falling yet?

[Lazamataz]

THANK GOD IT DID.

These jackasses.

Here is 'snowball Earth'

Here is Earth now.

Can we PLEASE just start killing these sons of bitches? Pretty please?

[irishtenor]

Well, I am sitting about 370 feet above sea level in Seattle. If the climate warms up enough, maybe I’ll have waterfront property in a tropical location, and never have to move! GO GLOBAL WARMING!!!!!!!!!!

[eggman]

You have to ignore the fact that conditions were very different back then and just believe that it can happen again because it supposedly happened before.

This also gives no reason for the melting of the ice that released the methane in the first place. If it was a "stable" snowball earth climate why did the ice melt and release the methane that caused the warming?

It is only stable until something changes. There are way too many things changing for anyone to be able to point to one factor as the definitive cause. That's why AGW is just so much hot air.

[hellbender]

Right. It’s an amazing feature of modern science that this kind of wildly speculative garbage can get credence. It’s really a racket designed to get more funding. If we continue to allow science to become politicized and converted into another arm of socialist propaganda, our society will suffer.

[writer33]

The sky is indeed falling.

:-)

[UCANSEE2]

“It is only stable until something changes. There are way too many things changing for anyone to be able to point to one factor as the definitive cause. That’s why AGW is just so much hot air. “

---

Isn’t it also a math thing?

The more the climate ‘changes’ , the more stable the graph of the average global temperature becomes.

The less it changes, the more those climate ‘changes’ affect the graph.

[TheWasteLand]

These guys need to get real jobs. This is just ridiculous.

[uscabjd]

No, this was well before the event that killed the dinosaurs - which was only 65 million yrs ago. No one knows why there was a snow ball earth, altho the position of the continents - with land masses over each pole - may have had something to do with it.

[William Tell]

The article calls the change "abrupt" but makes no mention of what that means. Could it mean "a day"? Could it mean "a month" or a "year"?

Or more likely, could it mean "a million years or so"? Could we cease our panic over "global warming" if it took a million years? I would think so, but I doubt that the liberals would like us to postpone for a couple thousand years a program that would permit them to dictate our lifestyles NOW.

And finally, how come the earth didn't just continue to warm until all life was burned to a crisp and the earth became uninhabitable? That didn't happen, did it?

[Wiseghy]

I’ve heard lots of different explainations using the methane effect. We’re going to hear lots, lots more about it.

Proponents usually forget that warming, of, say, Siberian permafrost, also results in rapid additional plant growth, which consumes CO2.