Study suggests 'snowball Earth' was real and was reversed by 'An ultra-high carbon dioxide atmosphere'

English: Earth, covered in ice.

Earth, covered in ice. (Photo credit: Wikipedia)

It makes you wonder what created all that CO2 millions of years ago.

From Louisiana State University

LSU researchers find new information about ‘Snowball Earth’ period

It is rather difficult to imagine, but approximately 635 million years ago, ice may have covered a vast portion of our planet in an event called “Snowball Earth.” According to the Snowball Earth hypothesis, the massive ice age that occurred before animal life appeared, when Earth’s landmasses were most likely clustered near the equator, precipitated relatively rapid changes in atmospheric conditions and a subsequent greenhouse heat wave. This particular period of extensive glaciation and subsequent climate changes might have supplied the cataclysmic event that gave rise to modern levels of atmospheric oxygen, paving the way for the rise of animals and the diversification of life during the later Cambrian explosion.

But if ice covered the earth all the way to the tropics during what is known as the Marinoan glaciation, how did the planet spring back from the brink of an ice apocalypse? Huiming Bao, Charles L. Jones Professor in Geology & Geophysics at LSU, might have some of the answers.

Bao and LSU graduate students Bryan Killingsworth and Justin Hayles, together with Chuanming Zhou, a colleague at Chinese Academy of Sciences, had an article published on Feb. 5 in the Proceedings of the National Academy of Sciences, or PNAS, that provides new clues on the duration of what was a significant change in atmospheric conditions following the Marinoan glaciation.

“The story is to put a time limit on how fast our Earth system can recover from a total frozen state,” Bao said. “It is about a unique and rapidly changing post-glacial world, but is also about the incredible resilience of life and life’s remarkable ability to restore a new balance between atmosphere, hydrosphere and biosphere after a global glaciation.”

Bao’s group went about investigating the post-glaciation period of Snowball Earth by looking at unique occurrences of “crystal fans” of a common mineral known as barite (BaSO4), deposited in rocks following the Marinoan glaciation. Out of the three stable isotopes of oxygen, O-16, O-17 and O-18, Bao’s group pays close attention to the relatively scarce isotope O-17. According to Killingsworth, there aren’t many phenomena on earth that can change the normally expected ratio of the scare isotope O-17 to more abundant isotope O-18. However, in sulfate minerals such as barite in rock samples from around 635 million years ago, Bao’s group finds large deviations in the normal ratio of O-17 to O-18 with respect to O-16 isotopes.

“If something unusual happens with the composition of the atmosphere, the oxygen isotope ratios can change,” Killingsworth said. “We see a large deviation in this ratio in minerals deposited around 635 million years ago. This occurred during an extremely odd time in atmospheric history.”

According to Bao’s group, the odd oxygen isotope ratios they find in barite samples from 635 million years ago could have occurred if, following the extensive Snowball Earth glaciation, Earth’s atmosphere had very high levels of carbon dioxide, or CO2. An ultra-high carbon dioxide atmosphere, Killingsworth explains, where CO2 levels match levels of atmospheric oxygen, would grab more O-17 from oxygen. This would cause a depletion of the O-17 isotope in air and subsequently in barite minerals, which incorporate oxygen as they grow. Bao’s group has found worldwide deposits of this O-17 depleted sulfate mineral in rocks dating from the global glaciation event 635 million years ago, indicating an episode of an ultra-high carbon dioxide atmosphere following the Marinoan glaciation.

“Something significant happened in the atmosphere,” Killingsworth said. “This kind of an atmospheric shift in carbon dioxide is not observed during any other period of Earth’s history. And now we have sedimentary rock evidence for how long this ultra-high carbon dioxide period lasted.”

By using available radiometric dates from areas near layers of barite deposits, Bao’s group has been able to come up with an estimate for the duration of what is now called the Marinoan Oxygen-17 Depletion, or MOSD, event. Bao’s group estimates the MOSD duration at 0 – 1 million years.

“This is, so far, really the best estimate we could get from geological records, in line with previous models of how long an ultra-high carbon dioxide event could last before the carbon dioxide in the air would get drawn back into the oceans and sediments,” Killingsworth said.

Normally, carbon dioxide levels in the atmosphere are in balance with levels of carbon dioxide in the ocean. However, if water and air were cut off by a thick layer of ice during Snowball Earth, atmospheric carbon dioxide levels could have increased drastically. In a phenomenon similar to the climate change Earth is witnessing in modern times, high levels of atmospheric carbon dioxide would have created a greenhouse gas warming effect, trapping heat inside the planet’s atmosphere and melting the Marinoan ice. Essentially, the Marinoan glaciation created the potential for extreme changes in atmospheric chemistry that in turn lead to the end of Snowball Earth and the beginning of a new explosion of animal life on Earth.

While previous work by Bao’s group had advanced the interpretation of the strange occurrence of O-17 depleted barite just after the Marinoan glaciation, there was still much uncertainty on the duration of ultra-high CO2 levels after meltdown of Snowball Earth. Bao’s discovery of a field site with many barite layers gave the opportunity to track how oxygen isotope ratios changed through a thickness of sedimentary rock. As the pages in a novel can be thought of as representing time, so layers of sedimentary rock represent geological history. However, these rock “pages” represented an unknown duration of time for the MOSD event. By using characteristic features of the Marinoan rock sequence occurring regionally in South China, Bao’s group linked the barite layer site to other sites in the region that did have precise dates from volcanic ash beds. Bao’s group has succeeded in estimating the duration of the MOSD event, and thus the time it took for Earth to restore “normal” CO2 levels in the atmosphere.

“To some extent, our findings demonstrate that whatever happens to Earth, she will recover, and recover at a rapid pace,” Bao said. “Mother Earth lived and life carried on even in the most devastating situation. The only difference is the life composition afterwards. In other words, whatever humans do to the Earth, life will go on. The only uncertainty is whether humans will still remain part of the life composition.”

Bao says that he had been interested in this most intriguing episode of Earth’s history since Paul Hoffman, Dan Schrag and colleagues revived the Snowball Earth hypothesis in 1998.

“I was a casual ‘non-believer’ of this hypothesis because of the mere improbability of such an Earth state,” Bao said. “There was nothing rational or logic in that belief for me, of course. I remember I even told my job interviewers back in 2000 that one of my future research plans was to prove that the Snowball Earth hypothesis was wrong.”

However, during a winter break in 2006, Bao obtained some unusual data from barite, a sulfate mineral dating from the Snowball Earth period that he received from a colleague in China.

“I started to develop my own method to explore this utterly strange world,” Bao said. “Now, it seems that our LSU group is the one offering the strongest supporting evidence for a ‘Snowball Earth’ back 635 million years ago. I certainly did not see this coming. The finding we published in 2008 demonstrates, again, that new scientific breakthroughs are often brought in by outsiders.”

Bao credits his research ideas, analytical work and pleasure of working on this project to his two graduate students, Killingsworth and Hayles, as well as his long-time Chinese collaborators. Bao brought Killingsworth and Hayles to an interior mountainous region in South China in December 2011, where the group succeeded in finding multiple barite layers in a section of rocks dating to 635 million years ago. This discovery formed a large part of their analysis and subsequent publication in PNAS.

“Nothing can beat the intellectual excitement and satisfaction you get from research in the field and in the laboratory,” Bao said.

###

Bao’s research is funded by the National Science Foundation and by the Chinese Academy of Sciences.

To read the original article, visit http://www.pnas.org/content/early/2013/02/05/1213154110.1.abstract.

To read more about Huiming Bao’s research, visit http://www.geol.lsu.edu/hbao/.

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So where’s the computation of the change in our spectrum the purported change in CO2 concentration is claimed to have caused ?

I recently watched this whole series:
http://store.discovery.com/prehistoric-disasters-dvd/detail.php?p=107097
and according to the program, when the asteroid smacked into Mexico and killed all of the dinosaurs, it also “released” all of the co2 that was being held in the rocks there.
Yes I know this is a different time period from “snowball earth”
I don’t recall how the explained the heating of the snowball.

Total, dillusional fiction

David, UK

So CO2 really is the mother of all climate drivers after all. That’s me sold.
[/sarc]

PaulR

Well written. This is how its done.

chris y

“An ultra-high carbon dioxide atmosphere, Killingsworth explains, where CO2 levels match levels of atmospheric oxygen, would grab more O-17 from oxygen.”
Do they really suggest that CO2 levels back then spiked up to 200,000 ppm?
If so, this provides another line of evidence that runaway greenhouse warming is impossible on Earth.

Bruce Voll

A scientist.
One who changes his theory to fit the available facts.
Seems like we found one here.

Interesting, although rather a mountain of inference that perhaps lacks an adequate consideration of alternative hypotheses. In particular, when he speaks of an atmosphere that is “half CO_2”, does he mean compared to oxygen? Both oxygen and nitrogen? Would an atmosphere that is half CO_2 (where by hypothesis the CO_2 has eaten O_17 differentially) not have directly observable effects in the chemical formation of carbonates from that era? Are there other ways either oxygen might have been differentially depleted or might isotope ratios have been altered by other exotic events, such as a gamma ray burst or million year alteration in the geosolar magnetic environment, e.g. causing it to be bound up as Ozone or some other oxide? And where the hell did the carbon come from? If one released 100% of the carbon dioxide bound up in the ocean one would multiply the atmospheric CO_2 only by a factor of roughly 60, that is to say, to an absolute maximum of perhaps 10 or 20% of the total atmosphere. But it isn’t terribly plausible that this would happen especially in a snowball Earth situation, because CO_2 is extremely stable in very cold water (which is why the ocean is such an enormous sink — the bulk if it is at the same 4K that it undoubtedly would have been during this cold episode).
So the best I can say after reading the article is “perhaps”, but I’m not certain the numbers add up convincingly or alternatives have been eliminated.
rgb

thingadonta

I might add that it is well known that rates of continental movement and break up were very high around this period, and I’ve read before that some have atttributed this high rate of plate tectonics to the high rates of evolutionary change-the ‘Cambrian explosion’. The high rate of plate tectonic movement and activity would have caused a high rate of volcanism and greenhouse gases, however one couldn’t really decribe this as ‘rapid’, in terms of time frames if would have been over millions/tens of millions of years.
Also, there were extensive phosphate deposits on the contintental shelves and oceans at the time which are speculated to have been crucial in the development of the Cambrian explosion-as phosphate is important in higher organisms, these deposits might also have formed under the unusual tectonic context at the time.

CO2 hypothesis is most likely nonsense. There were huge geological changes in the area of what is now parts of Africa (possibly caused by huge meteorite impact splitting Africa from South America. Carbonado diamonds of identical composition are found in the Central African Republic and Bahia region of Brazil)
Dating of zircons found in metamorphic rocks from the two ruby
deposits demonstrates the existence of Archean and Paleo –
proterozoic igneous rocks with emplacement ages between
2636 and 2448 Ma. These ancient rocks were reworked
much later (~640–600 million years ago) during the Pan-
African orogeny.

http://www.gia.edu/research-resources/gems-gemology/issues/fall2010-contents/FA10AB.pdf

phlogiston

This particular period of extensive glaciation and subsequent climate changes might have supplied the cataclysmic event that gave rise to modern levels of atmospheric oxygen, paving the way for the rise of animals and the diversification of life during the later Cambrian explosion.
No, the great oxygen “catastrophe” began 2.4 billion years ago, 1.8 billion years earlier than the Marinoan.
According to Bao’s group, the odd oxygen isotope ratios they find in barite samples from 635 million years ago could have occurred if, following the extensive Snowball Earth glaciation, Earth’s atmosphere had very high levels of carbon dioxide, or CO2.
This wholepaper is nothing but religiously driven wishful thinking. Did anyone explain to Bao that data actually exist already on the history of CO2 concentration in the atmosphere? CO2 was sky high – by today’s standards, THROUGHOUT the Marinoan/Varanger snowball earth ice age, as well as the Sturtian ice age that preceded it by a couple of hundred milion years. The peak of CO2 concentration actually followed these glaciations into the Cambrian reaching 10-15000 ppm but oxygen was still at levels similar to today, about 20%, far higher than CO2.
I cant believe the language of this paper. It seems sufficient for Bao to fantasise a scenario for it suddenly to become a serious scientific proposal. “What if oxygen only appeared inthe atmosphere in the Cambrian? What if CO2 magically ended the Marinoan ice age?” Yes science really is fun when you play by those rules, its just like writing novels or making films. A pure work of fiction.
From just some isotope ratios in barite crystals the whole history of earth’s atmosphere is re-written for compliance with the CO2 religion. This is utterly depressing rubbish.
To some extent, our findings demonstrate that whatever happens to Earth, she will recover, and recover at a rapid pace,” Bao said. “Mother Earth lived and life carried on even in the most devastating situation. The only difference is the life composition afterwards. In other words, whatever humans do to the Earth, life will go on. The only uncertainty is whether humans will still remain part of the life composition.
Did anyone explain to Bao the existence of a scientific discipline called biology. So life somehow “lived through” the Marinoan and the subsequent CO2 fantasy? What a malign effect all that CO2 obviously had on the bioshpere. What lived before the Marinoan/Varanger? Some bacteria, some “small shelly fauna”, some single celled and a few simple multicelled eukaryotes. And what emerged after the Marinoan after the CO2 devastation? Only the CAMBRIAN EXPLOSION YOU TOTAL MORON!!! Every single phylum of multicellular life (bar one or two) that now lives, emerged in the most remarkable explosion of life-forms in the earth’s history.
How can Bao call the Cambrian explosion “devastating” and be taken seriously and accepted for publication?
These high priests of CO2 satanism do not have history on their side when they argue that CO2 is a bad thing. But when you have political power on your side, and environmentalism is the new state religion, the beast and the antichrist (metaphorically) then history is yours to be written. That’s why its such fun like people like Bao with creative imaginations.

“To some extent, our findings demonstrate that whatever happens to Earth, she will recover, and recover at a rapid pace…”
*
This is why I never believed in anthropogenic catastophe. As a child my scientific parents taught me that the Earth self-regulated. If nature got out of balance, the automatic reactions that kick in will return that balance. You only have to look at the way a plague (of anything) disappears with or without human intervention to realize that.
They also taught me that plants breathe in CO2 and breathe out oxygen – and how that flips at night. Marvellous stuff.
The activists don’t need to be scared. They don’t need to cull our activities. They certainly don’t need to cull humans. If it’s necessary to the plot (Earth’s, that is, not activists), nature will deal with it. If the alarmists want us to end up back in caves in hunter-gather mode, then all they have to do is sit back and gleefully wait for Earth to do its thing. They don’t have to force us there.
Back to my parents – we didn’t always see eye to eye – but they did teach me stuff. Best of all my lessons perhaps is they taught me to not to be afraid of the dark and to look at the stars…
I have a lot to thank them for, I might have been a green-idiot were it not for them.

The basic problem with this theory is that the temperature response to CO2 is always logarithmic. Even if CO2 levels were to rise from zero to say 10,000 ppm surface temperatures could then only increase by at most 7 degrees. I suppose that the authors then rely on positive water feedbacks and a series of various other tipping points in order to explain the rest of their narrative.
Yawn !

The Cambrian Explosion might be a real flowering of life. But there is no doubt that some of the “Explosion” is the development of hard body parts and exoskeletons which greatly aids the preservation of evidence for and the variety of life.
The pregnant question is what allowed for the development of hard body parts? Could it be a significant change in ocean chemistry? Even if it had been a gradual change in ocean chemistry using up the buffering capacity of iron-rich waters until the pH and chemical composition of waters changed to allow for retention of calcarious structures that life could begin to use.
When it comes to the Pre-Cambrian, the Present is NOT key to the Past.
Models on Snowball Earth and Cambrian explosion: A synopsis
S. Maruyamaa, , , M. Santoshb
a Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551, Japan
b Faculty of Science, Kochi University, Akebono-cho 2-5-1, Kochi 780-8520, Japan
Abstract At:
http://www.sciencedirect.com/science/article/pii/S1342937X0800004X

Bill Illis

Bao’s previous study using this technique had the CO2 level at only 12,000 ppm at the end of this major glaciation event.
http://www.snowballearth.org/Bao08.pdf
The new study doesn’t really put a number on CO2 levels, it just says they were very high for a time.
http://www.pnas.org/content/early/2013/02/05/1213154110.1.full.pdf

Wait.. I thought the sun was the cause of all climate change.

sophocles

It’s frozen, so where did the CO2 come from?
If it was already there, how could it freeze over in the first place?
What other literature is cited in the article?

u.k.(us)

“To some extent, our findings demonstrate that whatever happens to Earth, she will recover, and recover at a rapid pace,” Bao said. “Mother Earth lived and life carried on even in the most devastating situation.
========
OMG, they have it backwards.
She wants to kill us, like it’s Her job.
She can’t be satiated.

jack mosevich

I read a few research papers on this and several postulate that volcanoes added the CO2

Roger Dewhurst

Soon after its agglomeration from debris in space the earth
must have been very largely molten. It still has a
molten iron core. The heat very probably came largely from the
radioactive decay of short lived transuranic elements which no longer
exist. Very possibly the atmospheric gases are the end products of the
decay of these transuranic elements. We will never know for certain.
It had to be largely molten for the core, mantle, oceanic crust and
continental crust to differentiate. The mantle consists of olivine rich
crystalline rock. At some point it was molten. It is not now. Much of
the oceanic crust and continental crust have been molten though not
necessarily at the same time. There is a measurable geothermal gradient
everywhere it can be measured. The geothermal gradient implies that the
earth as a whole is losing heat to space. Obviously when the earth was
hottest it was losing heat fastest. Now it is losing heat slowly. Thus
the cooling of the earth is explained. Carbon dioxide does not enter
into it.
Carbon, which must have been in largely inorganic crystalline form soon
after the agglomeration of this planet gradually combined with oxygen
and was, from little more than 500 million years ago, converted into
deposits of limestone, marble, peat, coal, oil and gas. Of course
throughout later geological time volcanoes incremented atmospheric
carbon dioxide almost as fast as it was decremented by the processes
described above.
That the earth should cool and the tenor of carbon dioxide should fall
fall together requires no other explanation. Needless to say periods of
intense volcanic activity and changes in the activity of the sun have precluded
them from falling in total lockstep.

Another explanation of the end of Snowball Earth is sufficiently large volcanic eruptions covered large areas of ice with dark low albedo material that caused melting. Once the melting starts (ignoring seasons) embedded ash from earlier eruptions accumulates on the surface progressively decreasing albedo in a positive feedback.
Accelerating surface melt from embedded material accumulating on the surface is what we see with Arctic sea ice, and with the Greenland and Antarctic ice sheets.
These dark debris bands are commonly seen in icebergs indicating several years of net surface melting before enough snow falls in a winter to cover them.

A reference to Early Cambrian and Pre-Cambrian (690 ma, 600 ma) Paleogeographic reconstructions.
Plate Tectonic and Paleogeographic Mapping: State of the Art*
By Christopher Scotese 1 Search and Discovery Article #40312 (2008)
Posted July 22, 2008
http://www.searchanddiscovery.com/documents/2008/08029scotese/index.htm
it has a 19 MB PDF, plus 10 individual linked figures and
three animations of 62, 180, 659 MB.
Also:
GCM simulations of snowball earth conditions during the Late Proterozoic
Gregory S. Jenkins, Steven R. Smith
Article first published online: 20 DEC 2012
Part of the abstract:

In order to simulate the Snowball Earth conditions that may have existed during the late Proterozoic we have conducted a series of GCM simulations using a simple 50-meter slab ocean, a reduced solar constant of 6% and varied CO2 concentrations. In this study, we vary the CO2 concentration from 100 to 3400-ppmv and use rotation rates corresponding to 18 and 24-hour day-lengths. We also examine the effects of increasing the poleward transport of heat by the oceans. Our results show that below a critical value of approximately 1700 ppmv of atmospheric CO2, sea-ice and sub-freezing temperatures occur from the poles to the Equator.

RockyRoad

A Snowball Earth would have very little moisture in the atmosphere–perhaps so little that clouds would be absent. Insolation would be at a maximum so getting the Earth warmed up after being covered with ice wouldn’t be that difficult. We could credit the sun for warming and melting the snow-bound Earth, not an unusually high level of CO2. Lack of clouds trump CO2 as the reason for the recovery.

pat

Not sure I buy this.

skorrent1

Assuming that there was such a thing as “snowball earth”, and assuming that the proxy actually measures the CO2 density in the atmosphere, that still leaves two major questions:
1) The logarithmic nature of IR energy absorption by CO2 makes higher levels of CO2 increasingly inefficient as a GHG.
2) The radically-changed albedo of a “snowball earth” may leave very little energy in the narrow IR windows in which CO2 can absorb radiation at all.
Is it possible that the study was predicated on a way to tie the current bug-bear, CO2, to interesting geologic observations?

Reblogged this on Public Secrets and commented:
Such is the power of Global Warming, that it can send CO2 millions of years into the past! (Look, you know someone among the cult will think of it.)

Theo Goodwin

“remarkable ability to restore a new balance between atmosphere, hydrosphere and biosphere after a global glaciation.”
should read:
“remarkable ability to restore a new balance AMONG atmosphere, hydrosphere and biosphere after a global glaciation.”

u.k.(us)

Steven Mosher says:
February 28, 2013 at 2:15 pm
Wait.. I thought the sun was the cause of all climate change.
================
At least you thought.

MattN

Science. Fiction.

Auto

My concern is cooling.
I don’t want cooling – even if it makes some climatologists [their word] look a little old-fashioned, shall we say.
A gentle warming – say 0.2 C/decade, for the next fifty years – would be accepable.
Go do it, Team.
Auto

Coach Springer

Going from: “According to Bao’s group, the odd oxygen isotope ratios they find in barite samples from 635 million years ago could have occurred if …” to “This kind of an atmospheric shift in carbon dioxide …” is missing the element of proving that the ratios *did* occur due to “very high levels of carbon dioxide.” So what is the current abnomral imbalance in atmoshperic CO2 they’re talking about? It’s pretty low on average, speaking in terms of geologic time. So, the heat and CO2 of prior ages of dinosaurs is normal after snowball earth while we are below normal?
With everything covered by ice trapping CO2 in the land, the tundra, the marshes, the peat, and the oceans, it could have been the hand of God that turned on the CO2. This kind of an act of God “is not observed during any other period of Earth’s history.” Study suggests this too.
“”Nothing can beat the intellectual excitement and satisfaction you get from [speculating about] research in the field and in the laboratory,’ Bao said.” Study suggests, indeed. But yeah, like he said, life and the earth will go on with or without us.

Scarface

So, what is the point here? High CO2 levels some 635 mln years ago?
Nothing new imho: http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif
Best remark I’ve read based on this graph: “Why I stopped worrying about CO2”
“In a phenomenon similar to the climate change Earth is witnessing in modern times, high levels of atmospheric carbon dioxide would have created a greenhouse gas warming effect, trapping heat inside the planet’s atmosphere and melting the Marinoan ice.”
This is hilarious. CO2 levels then were 6000 or 8000 ppm, or maybe even more, and now 400 ppm and they call that similar? LOL And besides that, I have not been able to find an explanation in this new study of why CO2 was the cause of the warming. If CO2 was that high and causing warming, how could it have been so cold in the first place? I personally think it had something to do with THE SUN. How come the good professor has found a way to prove snowball earth did really happen and then turns it into a CAGW gospel? I think that has to do with MONEY.

wikeroy

“In a phenomenon similar to the climate change Earth is witnessing in modern times, high levels of atmospheric carbon dioxide would have created a greenhouse gas warming effect, trapping heat inside the planet’s atmosphere and melting the Marinoan ice.”
There it is, the reason for the whole paper.
If there was so much CO2, and this led to the ice melting, then I have a question;
Was the CO2 there when the ice formed? If so, how could the ice form with the CO2 already there? If it wasnt there when it froze up, where did the CO2 come from after everything was frozen?

So… we should cut CO2 levels so we can all die in another Snowball Earth.
I’m sold.

KR

Bob Armstrong“where’s the computation of the change in our spectrum”
Try http://forecast.uchicago.edu/models.html, Modtran IR model (older code, but good for a rough estimate), with a CO2 concentration of 13% of the atmosphere, or 130,000ppm. That’s an estimated CO2 level to break the Earth out of a “Snowball” state (see http://onlinelibrary.wiley.com/doi/10.1029/2000GL011836/abstract) with some open tropical waters (broader estimates are 10-30%).
According to the ModTran code (using standard US atmos., standard cirrus, 70km looking down), that corresponds to a forcing of ~26.5 W/m^2 over current CO2 levels.

A Snowball Earth is the wrong metaphor.
It is a Europa Earth where single and multi-cellular life that thrives in the ecological niches of inevitable cracks in the ice.
Model THAT, GCM’ers!

astonerii

Lets see if I get this right.
CO2 absorbs the radiant energy of ice and warms the planet enough to melt said ice?

Jungle Jim

“It makes you wonder what created all that CO2 millions of years ago.”
-T. Rex and the Velociraptors burning coal to stay comfy.

Joe Prins

Agree with Wikeroy.
Seems to me that there needs to be an explanation somewhere of the inert Co2 before snowball earth happened and the sudden miraculous chemical transformation of Co2 to warm this, so scientific, Mother earth.
Please genuflect when pronouncing that so holy phrase./sarc

Michael John Graham

The first thing that caught my eye was the model of the percambrian “snowball earth” with a modern distribution of the Americas-younger than 65my bp. An indicator of other deficiencies of awareness? Then there is the anomaly of all the high country being ice free, though if all the water was under ice, sublimation might possibly do that, but why would it be where the temperature should be lowest?
Then there is the idea of the atmosphere and the hydrosphere (and all the surviving life forms in it) being separated by a very thick layer of ice and that this would cause ramping up of the carbon dioxide towards 20%? Where from? Do we assume catastrophic vulcanism or a nasty plot by aliens? At least the authors should suggest a mechanism. All that is said is “could have” which requires “how?”
Then there is the matter of the O isotope ratios. If carbondioxide is pulling oxygen from the atmosphere, this implies the carbondioxide is actually forming in the atmosphere. What from?
If it is there anyway , what is the reason for it to undergo oxygen isotope exchange and if it did, the fastest moving isotope is still O/16 so the atmosphere should be relatively enriched in O/17 and O/18 but more so in O/18 which is the reverse of the barite anomaly.
Or is this all a hoax and I’ve just been succered into responding?

So CO2 levels were ‘very high’ for a ‘time’. Well, the paper probably got him a grant or two since it blames CO2 for global warming.
Snowball earth is cyclical. And CO2 has been very high in the geologic past, even during snowball earth phases, so this paper is pure speculation.
Good luck with the grants, though.

Bill Illis

Here are the Continental positions just as this Snowball Earth was starting. Super-Continent Pannotia which was generally moving south at this point.
http://www.scotese.com/images/650.jpg
This study shows how the Snowball happened peaking at 635 Mya.
http://www.meteo.mcgill.ca/~tremblay/Courses/ATOC530/Hyde.et.al.Nature.2000.pdf
http://upload.wikimedia.org/wikipedia/en/d/dc/SnowballSimulations.jpg
http://www.nature.com/nature/journal/v405/n6785/images/405425aa.2.gif
Pretty simple. Glaciers build up on land – Super-Continent Pannotia – which was concentrated over the South Pole. Glaciers build up at the South Pole/central spreading region to 5 kms high. They spread out by gravity across all the land and continental shelf possible. Earth Albedo rises to close to 50%. Ocean freezes up to 30S and 30N. Snowball ends when Super-Continent Pannotia splits down the middle (as they tend to do) and land moves away from the South Pole.
http://wdict.net/img/pannotia.jpg
Perfectly explainable in logical simple sensible terms (and without any magical need to invoke CO2 at all).

Good article, and quite interesting. Looks like an area that should get some more funding $$
“In a phenomenon similar to the climate change Earth is witnessing in modern times, high levels of atmospheric carbon dioxide would have created a greenhouse gas warming effect,…”
Really?
“An ultra-high carbon dioxide atmosphere, Killingsworth explains, where CO2 levels match levels of atmospheric oxygen,”
That does not sound even remotly “similar” to our current situation.

Rud Istvan

As much as I do think Snowball Earth happened, I do not think it happened as Wikipedia illustrates. Which were adopted here. Simple fact that Wegener’s continental drift says could not have been so. At the time posited, Svalbard would have been near the south pole, not the north pole. The transit from south to north over this time rather throws a monkey wrench into static geologic theories. Just facts.

All well and good but I am still a bit skeptical about both Snowball Earth and about these levels of CO2. It all sounds net and tidy but I have not read the paper yet. My experience with earth science tells me nothing is ever neat, tidy and all that straight forward. That’s what keeps us earth scientists in business.

phlogiston

Roger Dewhurst says:
February 28, 2013 at 2:31 pm
Soon after its agglomeration from debris in space the earth
must have been very largely molten. It still has a
molten iron core. The heat very probably came largely from the
radioactive decay of short lived transuranic elements which no longer
exist. Very possibly the atmospheric gases are the end products of the
decay of these transuranic elements.

Both the 238U and 235U transuranic series end in stable lead (Pb). Is Pb a gas? Can you breathe it? Can plants photosynthesise it? IMHO, no. The only gas in the transuranic series is radon in all its isotopes with half lives no more than 4 days. (An inert gas, while it lasts.)

Roger Dewhurst

U234 etc are still present. The decay chains for all the extant nuclides are known. I was referring short life nuclides of large atomic weight which no longer exist. That is what I meant by trans uranic. We have no means of knowing just what was created in the big bang. If the gases we know travelled through space along with particulate debris I have to wonder how that happened. If the matter from which the earth was formed was particulate I have to wonder how it was heated up to melting point. The easiest explanation for that is the heat liberated in the decay of short half life nuclides of which we now have no experience or knowledge.

To answer a question that has been asked several times.
The paper does not say how the CO2 arrived, but it does indicate that it was not there before snowball earth
“Normally, carbon dioxide levels in the atmosphere are in balance with levels of carbon dioxide in the ocean. However, if water and air were cut off by a thick layer of ice during Snowball Earth, atmospheric carbon dioxide levels could have increased drastically. ”
The paper is stating that the normal ballance between air and ocean could have been disrupted by snowball earth, allowing the CO2 content to rise. I would also like to know if there was a hypothisised driver of this new CO2.

Kev-in-Uk

Total, utter and complete bulldust, IMHO.
Firstly, snowball earth has to be absolutely proven – which to my knowledge, it isn’t.
Second, the degree of ‘snowballness’ needs to be confirmed also – I’m not convinced of the globality…
Third – everyone is forgetting what caused the snowball earth in the first place! It stands to reason that it must’ve gotten really cold – but why? Moving on – if it did get really cold – what is the reason for this? Obviously if solar power is constant (/sarc) it must have been a climatalogical/biospherical reason (or Extraterrestrial one!). If you have a warm world, which cools – something must have changed – on the realistic assumption that earths emissivity didn’t suddenly double (again why would it?) – the incoming energy must have somehow reduced! End of! Yes, once ice cover increased, albedo may have increased as a positive feedback – but hey – somewhere, the incoming energy was ‘lost’- by very a significant margin. Anyway, it is not unreasonable to deduce that whatever caused the cooling – must have reversed – simply ‘inventing’ an ultra-CO2 atmosphere is ridiculous when considering the general palaeoclimatic variations thought/believed to have existed elsewhere through Earths history……….
and for those who want to argue – I am not saying it is all solar – I am saying that palaeo evidence will never be able to give us clear indications of ‘single’ causes. Everyone can ‘believe’ a temporary solar energy loss (for some reason, be it orbital, etc) and a positive feedback from albedo – but isolating a CO2 event for the thawing? Come on! – WTF generated the ‘new’ CO2??? – the place was supposedly covered in ice – virtually lifeless – but CO2 magically appears from nowhere??? – never mind, it probably seeped through the ice from the underlying carbonates??

phlogiston

Here’s a nice animation of continental drift since 600 million year ago (and 100 million years from now).

oldfossil

This is pretty cool science. It helps to establish the sequence of events that led to the drop in CO2 and the surge in free oxygen that enabled the Cambrian explosion. Science builds its massive edifices brick by brick and this study could be a very valuable contribution.