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Why Didn't Early Earth Freeze? The Mystery Deepens (Another CO2 hypothesis is debunked!)
ScienceNOW ^ | March 31, 2010 | Phil Berardelli

Posted on 04/04/2010 8:02:57 AM PDT by neverdem

Enlarge Image
sn-youngsun.jpg
Ironclad? Analyses of rocks in an ancient Greenland formation debunk the idea of an early greenhouse Earth.
Credit: M. Rosing

Dial back the clock nearly 4 billion years, to a time called the Archean, and the sun would appear about 30% dimmer than it is now. That's a problem: It couldn't have warmed Earth enough to keep the seas from becoming permanent ice sheets. Yet overwhelming geological evidence indicates that liquid water has existed on our planet since the seas formed more than 4 billion years ago, even during the deepest ice ages. What could have provided the added warmth?

In 1972, famed astronomer Carl Sagan proposed that the answer lay in the atmosphere. Sagan and his co-author George Mullen hypothesized that carbon dioxide (CO2) concentrations were much higher during the Archean—possibly 100 times higher than they are today—and therefore the atmosphere could retain enough heat to keep the planet from freezing. But so far, no one has found convincing data that Earth was once a super greenhouse. And now researchers have uncovered strong evidence to the contrary.

A team led by earth scientist Minik Rosing of the University of Copenhagen analyzed iron-bearing rocks in southwestern Greenland that were 3.8 billion years old. They focused on two minerals, magnetite and siderite, that can provide a bellwether of the CO2 concentrations in the atmosphere. Too much CO2, and magnetite can't form, whereas the opposite is true for siderite. Based on the ratio of the minerals, the team reports in tomorrow's issue of Nature that CO2 levels during the Archean could have been no higher than about 1000 parts per million—about three times the current level of 387 ppm and not high enough to compensate for the weak sun.

The results were "very surprising," Rosing says. As to the question of what kept the planet warm instead of CO2, he says his research points to two possibilities. First, Earth's land masses were much smaller billions of years ago, meaning that the oceans, which generally are darker than continents, could absorb more of the sun's heat. Second, because life was brand new, organisms were manufacturing little of the gases that help clouds form. So, more sunlight reached the surface.

There are bound to be other factors, Rosing says. "I think that our paper is just one link in a long chain of further refinements of our understanding of the early Earth and of the dynamics of our planet."

Earth scientist James Kasting of Pennsylvania State University, University Park, thinks it's premature to discard the greenhouse-gas option. Temperatures during the Archean were at least as high as they are today, despite the weaker sun, he says. It's difficult to account for the warmth using just the mechanisms suggested in this paper, Kasting says. "So, I think there is still a need for additional greenhouse gases."


TOPICS: Crime/Corruption; Culture/Society; Extended News; Politics/Elections
KEYWORDS: abiogenesis; biogenesis; catastrophism; climatechange; earlyearth; globalwarming; godsgravesglyphs; magnetite; originoflife; siderite
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Magnetite is a ferromagnetic mineral with the chemical formula Fe3O4and the common chemical name ferrous-ferric oxide, which indicates the mineral comprises both a ferrous component, FeO (wüstite), and a ferric component, Fe2O3 (hematite). Magnetite is one of several types of iron oxide and its official (IUPAC) name is iron(II,III) oxide.

Siderite, aka chalybite, is a carbonate of iron, FeCO3.

1 posted on 04/04/2010 8:02:58 AM PDT by neverdem
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To: neverdem; Amagi; Beowulf; Tunehead54; Clive; Fractal Trader; tubebender; marvlus; ...
 


Beam me to Planet Gore !

The Competitive Enterprise Institute will be bestowing the Julian Simon Award on Steve McIntyre and Ross McKitrick for their efforts in debunking Mann's hockey stick at CEI's 2010 Dinner, June 17 at Hyatt Regency Capitol Hill 400 New Jersey Ave. NW Washington, DC 20001.

2 posted on 04/04/2010 8:12:10 AM PDT by steelyourfaith (Warmists as "traffic light" apocalyptics: "Greens too yellow to admit they're really Reds."-Monckton)
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To: neverdem

Wouldn’t earth 4 billion years ago have been quite a bit warmer on the inside? Like a pie fresh out of the oven? That would have made the crust warmer as well.


3 posted on 04/04/2010 8:15:19 AM PDT by Moltke (DOPE will get you 4 to 8 in the Big House - HOPE will get you 4 to 8 in the White House.)
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To: neverdem
WHY DIDN'T EARLY EARTH FREEZE?
Very simple answer. Because GOD didn't want it to.. . .
4 posted on 04/04/2010 8:16:27 AM PDT by DeaconRed (Red Neck, Blue Collar - Paycheck, Few Dollars . . . . . My favorite song today. . . .)
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To: Moltke
The answer is that the residual heat from gravitational collapse would have dissipated quite quickly ~ couple of hundred million years in fact ~ or even faster.

What keeps Earth's interior warm is radioactive decay ~ the current proposal is that thorium is the main source, but there are other possibilities ~ maybe even a natural uranium reactor at the central part of the core!

5 posted on 04/04/2010 8:19:41 AM PDT by muawiyah ("Git Out The Way")
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To: neverdem

Gortex.


6 posted on 04/04/2010 8:20:38 AM PDT by Larry Lucido
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To: steelyourfaith

Why don’t we put Al Gore in Professor Peabody’s “Way Back Machine” and send him back four million years and let him investigate.


7 posted on 04/04/2010 8:22:18 AM PDT by donhunt (The Obama Administration got the contempt of the American people the hard way. They earned it.)
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To: Moltke

Not to mention the fact that there was far more volcanism going on at the time.


8 posted on 04/04/2010 8:28:52 AM PDT by cripplecreek (Remember the River Raisin! (look it up))
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To: neverdem

An additional greenhouse effect would not have been enough to keep the Earth from turning into a complete iceball.

There had to be lower Albedo (reflectance of sunlight) by clouds / atmospheric gases as well.


9 posted on 04/04/2010 8:41:21 AM PDT by JustDoItAlways
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To: steelyourfaith

ping


10 posted on 04/04/2010 8:42:21 AM PDT by Wuli
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To: donhunt

Only if we can leave him there.

LLS


11 posted on 04/04/2010 9:10:21 AM PDT by LibLieSlayer ( WOLVERINES!)
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To: Moltke; Voter#537

But how did God bring that about?

It’s possible that iron was in heavier abundances during early solar system history (especially in its inner parts) and that it formed Earth’s, and other terrestrial planetary cores early on. That, with radiogenics also settling out, may have provided enough heat for this not only on Earth, but also on Mars which seems to have had an abundance of early water on its surface as well.


12 posted on 04/04/2010 10:03:10 AM PDT by onedoug
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To: 75thOVI; aimhigh; Alice in Wonderland; AndrewC; aragorn; aristotleman; Avoiding_Sulla; BBell; ...
Thanks neverdem. Sagan -- who was probably the first global warming demagogue -- mentioned, so, well, y'know...
 
Catastrophism
 
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13 posted on 04/05/2010 8:03:42 PM PDT by SunkenCiv ("Fools learn from experience. I prefer to learn from the experience of others." -- Otto von Bismarck)
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To: StayAt HomeMother; Ernest_at_the_Beach; 1ofmanyfree; 21twelve; 240B; 24Karet; 2ndDivisionVet; ...

· join list or digest · view topics · view or post blog · bookmark · post a topic · subscribe ·

 
Gods
Graves
Glyphs
Thanks neverdem.
Dial back the clock nearly 4 billion years, to a time called the Archean, and the sun would appear about 30% dimmer than it is now. That's a problem: It couldn't have warmed Earth enough to keep the seas from becoming permanent ice sheets. Yet overwhelming geological evidence indicates that liquid water has existed on our planet since the seas formed more than 4 billion years ago, even during the deepest ice ages.
To all -- please ping me to other topics which are appropriate for the GGG list.
GGG managers are SunkenCiv, StayAt HomeMother, and Ernest_at_the_Beach
 

·Dogpile · Archaeologica · LiveScience · Archaeology · Biblical Archaeology Society ·
· Discover · Nat Geographic · Texas AM Anthro News · Yahoo Anthro & Archaeo · Google ·
· The Archaeology Channel · Excerpt, or Link only? · cgk's list of ping lists ·


14 posted on 04/05/2010 8:04:20 PM PDT by SunkenCiv ("Fools learn from experience. I prefer to learn from the experience of others." -- Otto von Bismarck)
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Early Water on Earth
Geotimes | February 2003 | Salma Monani
Posted on 02/09/2003 7:22:57 PM EST by CalConservative
http://www.freerepublic.com/focus/news/839466/posts

Early Earth Likely Had Continents, Was Habitable, According To New Study
University of Colorado at Boulder | 2005-11-18 | University of Colorado at Boulder
Posted on 11/18/2005 11:32:59 PM EST by dila813
http://www.freerepublic.com/focus/news/1525001/posts

Sea floor records ancient Earth
BBC | Friday, 23 March 2007, 09:09 GMT
Jonathan Fildes Science and technology reporter, BBC News
Posted on 03/24/2007 2:06:03 AM EDT by Ernest_at_the_Beach
http://www.freerepublic.com/focus/news/1805973/posts

Crusty Old Discovery Reveals Early Earth’s History
(3.8 billion years old outer crust)
LiveScience.com on yahoo | 3/24/07 | Robert Roy Britt
Posted on 03/24/2007 10:40:45 PM EDT by NormsRevenge
http://www.freerepublic.com/focus/news/1806290/posts

Diamonds Tell Story Of Earth’s Beginning
The Telegraph (UK) | 8-22-2007 | Roger Highfield
Posted on 08/22/2007 9:48:58 PM EDT by blam
http://www.freerepublic.com/focus/news/1885157/posts


15 posted on 04/05/2010 8:09:40 PM PDT by SunkenCiv ("Fools learn from experience. I prefer to learn from the experience of others." -- Otto von Bismarck)
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To: SunkenCiv

http://www.marxists.org/reference/subject/philosophy/works/us/gaia.htm

Life first appeared on the Earth about 3,500 million years ago. From that time until now, the presence of fossils shows that the Earth’s climate has changed very little. Yet the output of heat from the sun, the surface properties of the Earth, and the composition of the atmosphere have almost certainly varied greatly over the same period.

The chemical composition of the atmosphere bears no relation to the expectations of steady-state chemical equilibrium. The presence of methane, nitrous oxide, and even nitrogen in our present oxidising atmosphere represents violation of the rules of chemistry to be measured in tens of orders of magnitude. Disequilibria on this scale suggest that the atmosphere is not merely a biological product, but more probably a biological construction: not living, but like a cat’s fur, a bird’s feathers, or the paper of a wasp’s nest, an extension of a living system designed to maintain a chosen environment. Thus the atmospheric concentration of gases such as oxygen and ammonia is found to be kept at an optimum value from which even small departures could have disastrous consequences for life.

The climate and the chemical properties of the Earth now and throughout its history seem always to have been optimal for life. For this to have happened by chance is as unlikely as to survive unscathed a drive blindfold through rush-hour traffic.

Source: Gaia A new look at life on Earth by J E Lovelock, publ. Oxford University Press 1979.


...the presence of fossils shows that the Earth’s climate has changed very little...


16 posted on 04/05/2010 8:45:28 PM PDT by Fred Nerks (fair dinkum!)
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To: cripplecreek

Even today, I think that if it were not for the internal heat of the Earth, we would freeze over - the amount of sunlight we receive is not enough to stop it.


17 posted on 04/06/2010 8:38:09 AM PDT by djf
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To: Fred Nerks
My understanding is that modern reconstructions of the Archean show a dramatically different atmosphere from the present, one depleted in oxygen. A billion years of work by stromatolites changed all that and injected the oxygen needed for modern life.

http://www.ucmp.berkeley.edu/precambrian/archaean.html

18 posted on 04/06/2010 10:38:22 AM PDT by colorado tanker
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To: neverdem

I see no mention in this article of the other greenhouse gases; namely methane, ammonia or water vapor.

The solar models also have a lot of variability. They predict the sun was anywhere from 30% to 75% less bright. Maybe they’re wrong.


19 posted on 04/06/2010 10:51:41 AM PDT by <1/1,000,000th%
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To: colorado tanker
And when Lovelock wrote ...the presence of fossils shows that the Earth’s climate has changed very little...

all he did was prove what an idiot he was.

20 posted on 04/06/2010 1:46:37 PM PDT by Fred Nerks (fair dinkum!)
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