Yowzer! "sea ice extended to the equator 716.5 million years ago"

From Harvard University Science: Scientists find signs of ‘snowball Earth’

Research suggests global glaciation 716.5 million years ago

Steve Bradt

Harvard Staff Writer

Geologists have found evidence that sea ice extended to the equator 716.5 million years ago, bringing new precision to a “snowball Earth” event long suspected of occurring around that time.

http://www.physast.uga.edu/~jss/1010/ch10/10-35.jpg

Click for larger image - From the University of Georgia Tutorial on Terrestrial Atmosphere: http://www.physast.uga.edu/~jss/1010/ch10/ovhd.html

Led by scientists at Harvard, the team reports on its work in the latest edition of the journal Science . The new findings — based on an analysis of ancient tropical rocks in remote northwestern Canada — bolster the theory that the planet has, at times in the past, been covered with ice at all latitudes.

“This is the first time that the Sturtian glaciation [the name for that ice age] has been shown to have occurred at tropical latitudes, providing direct evidence that this particular glaciation was a ‘snowball Earth’ event,” said lead author Francis A. Macdonald, an assistant professor in Harvard’s Department of Earth and Planetary Sciences. “Our data also suggests that the Sturtian glaciation lasted a minimum of 5 million years.”

The survival of eukaryotic life ­­­— organisms composed of one or more cells, each with a nucleus enclosed by a membrane — throughout this period indicates that sunlight and surface water remained available somewhere on the surface of Earth. The earliest animals arose at roughly the same time, following a major proliferation of eukaryotes.

Even on a snowball Earth, Macdonald said, there would be temperature gradients, and it is likely that ice would be dynamic: flowing, thinning, and forming local patches of open water, providing refuge for life.

“The fossil record suggests that all of the major eukaryotic groups, with the possible exception of animals, existed before the Sturtian glaciation,” Macdonald said. “The questions that arise from this are: If a snowball Earth existed, how did these eukaryotes survive? Moreover, did the Sturtian snowball Earth stimulate evolution and the origin of animals?”

“From an evolutionary perspective,” he added, “it’s not always a bad thing for life on Earth to face severe stress.”

The rocks that Macdonald and his colleagues analyzed in Canada’s Yukon Territory showed glacial deposits and other signs of glaciation, such as striated clasts, ice-rafted debris, and deformation of soft sediments. The scientists were able to determine, based on the magnetism and composition of these rocks, that 716.5 million years ago they were located at sea level in the tropics, at about 10 degrees latitude.

“Because of the high albedo [light reflection] of ice, climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over,” Macdonald said. “So our result implies quite strongly that ice would have been found at all latitudes during the Sturtian glaciation.”

Scientists don’t know exactly what caused this glaciation or what ended it, but Macdonald says its age of 716.5 million years closely matches the age of a large igneous province stretching more than 930 miles from Alaska to Ellesmere Island in far northeastern Canada. This coincidence could mean the glaciation was either precipitated or terminated by volcanic activity.

In this photo from Canada's Yukon Territory, an iron-rich layer of 716.5-million-year-old glacial deposits (maroon in color) is seen atop an older carbonate reef (gray in color) that formed in the tropics. Photograph courtesy of Francis A. Mcdonald/Harvard University

Macdonald’s co-authors on the Science paper are research assistant Phoebe A. Cohen; David T. Johnston, assistant professor of earth and planetary sciences; and Daniel P. Schrag, Sturgis Hooper Professor of Geology and Professor of Environmental Science and Engineering, all of Harvard. Other co-authors are Mark D. Schmitz and James L. Crowley of Boise State University; Charles F. Roots of the Geological Survey of Canada; David S. Jones of Washington University in St. Louis; Adam C. Maloof of Princeton University; and Justin V. Strauss.

The work was supported by the Polar Continental Shelf Project and the National Science Foundation’s Geobiology and Environmental Geochemistry Program.

In this photo from Canada's Yukon Territory, an iron-rich layer of 716.5-million-year-old glacial deposits (maroon in color) is seen atop an older carbonate reef (gray in color) that formed in the tropics. Photograph courtesy of Francis A. Mcdonald/Harvard University

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172 thoughts on “Yowzer! "sea ice extended to the equator 716.5 million years ago"

  1. Another unsubstantiated tipping point: “Because of the high albedo…of ice, climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over,” Macdonald said. “So our result implies quite strongly that ice would have been found at all latitudes during the Sturtian glaciation.”
    Bull robust.

  2. Wow, isn’t that special? It was CO2 that saved our planet.
    Wow, isn’t that special? The hot house planet period did not kill off every last creature on the planet or boil the oceans.
    Wow, isn’t it special? Every change in temperature has to be caused by CO2, as if there could not possibly have been some other reason.

  3. “The questions that arise from this are: If a snowball Earth existed, how did these eukaryotes survive?
    Probably on the sea floor sustained by heat and nutrients provided by hydrothermal vents.

  4. What really happen was a world wide flood, in which water came down from the sky and bursted out of the surface of the Earth all at once. This caused a simultanious and (comparered to millions of years) instantaneous movement of all land masses to were they are presently. This is all completely verifiable, you just have ask the right scientists. Which by the way the Earth is still holding all that water somewhere.

  5. Just saw a program on PBS about life around Antarctica. Apparently, there are 250 species found at both poles.
    How did that happen, I wondered.
    Here’s a possible answer.
    Thanks!

  6. Monty Python had a skit based on Parliament Question time and basically sums up the frustration We all feel with this AGW and CRU, AL, and Patchy Morals:
    ‘[man stands up]………..S I C K and T I R E D people, are sick and tired of being told that sick and tired people are S I C K and T I R E D!!!!…………And I’m Sick and tired of it!!…………..”
    (Parliament: Shouts, Cheers, condemnations, claps and the chant: Rah Rah Rah!!!)

  7. Anthony, I am a regular visitor, but primarily a lurker. I appreciate what you do very much. I think that you have done an excellent job of staying on top of the vast amount of rapid fire information since Climategate broke wide open. It has taken plenty of effort to do what you have done. Please be proud of yourself.
    I believe that basic geology is the real key to understanding climate and has been left out of much, if not essentially all, of the climatologists studies. You do a good job of bringing a wide mix of science to your readers.
    Thanks, JFD.

  8. Something’s do not seem quite right with the theory that goes along with the snowball effect.
    Gases from the volcanoes would be far more than just CO2.
    The term CO2 is often used too freely for everything.
    Now if the soot from the valcoes covered many areas then the heat from the sun would melt the snows quicker.

  9. These late PreCambrian glacial deposits occur from the US/Montana border all the way to the Yukon and NWT where this study found them. Their occurrence was well known when I worked in these areas in the late 1970’s and early 1980’s.
    What is interesting in this study is that they were able to get a latitude in the tropics. The assumption we worked under was that these were deposited in higher latitudes. That never made sense to me given that only marginally younger rocks of the lower Cambrian were dominated by carbonates more typical of tropical environments.
    Nice to see a puzzle solved. Science marches on.

  10. That’s sweet.
    Can you imagine if it happened again?
    Totally, totally solves the problem of excess carbon production resulting from saying, “No,” to a paper back at the grocery store.

  11. Thanks to CO2, the earth warmed up again. And CO2 is now classified as a pollutant by the EPA?

  12. How are they so sure that a stop in the Ocean CO2 cycle supposedly leading to a buildup of atmospheric CO2 due to volcanic offgassing caused a ‘hothouse Earth’ effect?

  13. Wow, 716.5 million years. I would have settled for 716.4! 100,000 years, no charge! BONUS!

  14. “Our data also suggests that the Sturtian glaciation lasted a minimum of 5 million years.”
    I think I’ll take a little more AGW, please.

  15. Now that’s what I call a Global Reset Button.
    And to think that there are some people out there who would actually risk Snowball Earth to cut a measly degree or two off the Global Temp.

  16. Co-author Charles F. Roots of the GSC. I remember him from my university days way back when. A gonzo geologist and all around great guy.

  17. Sigh…I don’t see the logic in refusing assumptions made by AGW proponents only to swallow all the assumptions made in this Harvard study. Nobody can know those kind of details about what was supposed to be happening “way back yonder.” It’s all speculation, just like when warmers line up “appearances” and then just assume all the details of AGW! Our actual knowledge of unique, unrepeatable events is very limited.

  18. Sheffield BM(Smallz79) (19:36:10) :
    I agree, except I believe the earth as originally formed by God, was only shallow seas and low hills. The disruption of the flood led to the tall mountains and deep oceans so all the water is still here around us. BTW, you and I will both start seeing posts decrying the presence of creationists and young earth crazies. Wait for it; it’ll happen.
    God bless,
    Walter
    Reply: I had better not. It stops now. You believe that, other people believe differently and that is the extent this discussion will be allowed to continue. ~ ctm

  19. Yup, Earth’s mercurial climate can certainly be pushed and pulled into some extreme states. People should feel quite lucky that the very stable Holocene era of the last 12,000 years has allowed the development of agriculture and civilization.
    Hopefully nothing comes along to knock the climate system into a different, civilization ending state sooner than necessary – a global version of previous regional climate shifts that ended great civilizations.

  20. With sea ice lapping up on beaches in the tropics, think how convenient it must’ve been to make Sturtian-era margaritas! No wonder the period led to animal life.

  21. I’ve modified and reposted an OT comment from another thread that is on topic here.
    I’ve Googled the theory, and note that while it has been debunked by at least one scientific study, and is not widely accepted, Connolley will not permit the Wikipedia article to be modified to reflect this.
    The magical CO2 which is supposed to have ‘greenhoused’ the earth back to conditions more like what we experience now is supposed to have been generated by volcanoes. It occurs to me that CO2 concentrations argued to be necessary to have pulled the earth out of this condition at 130,000 ppm puts the warmists in rather a self-contradictory position: while CO2 is hypothesized to have been the forcing agent that brought the ’snowball’ condition to an end, the posited concentrations did not succeed in making the earth come to a boil – they merely allowed the ice to melt sufficiently to allow the Cambrian explosion!
    Presumably the subsequent reduction of CO2 concentrations to modern concentrations was facilitated by autotrophs (i.e. photosynthesizing life forms). Life survived in far more extreme conditions and even at the worst levels of human activity, we are not projected to put anything near those levels of CO2 in the atmosphere. Just food for thought.

  22. vigilantfish (19:47:10)
    Interesting link, thanks, also…Those ‘dropstones’ are quite distinctive.

  23. Evidence of this has been around since Budyko crafted his famous model back in ’79. We’ve had strong evidence via banded iron formations, paleomagnetic characteristics of rock, and glacial sediments from many locations, for quite some time.
    From everything we know, it’s hard to explain exactly how Earth glaciated to the mid-latitudes (roughly the critical point, at which, the ice would enter an albedo feedback and march on to the tropics). The Milkanovitch cycles are nowhere near strong enough. On the other hand, escaping one is more imaginable: volcanic emissions mildly warm the planet over a long period of time, when sinks like plants would be scarce, and this releases some permafrost emissions and methane-clathrates, etc. You need quite a strong forcing to push that ice back to its critical point, though, because it will tend to want to keep returning to the equator.
    Food for thought: of the models I’ve studied, they all allow a totally ice-free, partially ice-covered, and completely glaciated Earth to exist under our current solar constant. Given, it does not include things like the biosphere or the aforementioned volcanoes, but the high-albedo of a completely glaciated globe is enough to create a ‘stable’ climate, as is one with ice up to the mid-latitudes.

  24. Am I correct in assuming that the illustration was not part of the PR, but added here. From the comments about CO2, people seem to be confusing the language in the artwork with the statement from Harvard which doesn’t really feature much discussion of CO2.

  25. I know nothing about Geology and must just be confused, but how did the rocks from within 10 degrees latitude of the equator make it to a remote part of Northwestern Canada? Is the magnetism of the rocks enough to know for certain that they are from the tropics?
    Why not find rock in the tropics that show the characterstics of glaciation? if there were glaciers in the tropics then why can’t we see evidence in the tropics rather than in the Yukon in Canada?

  26. astonerii (19:16:44) :
    Wow, isn’t it special? Every change in temperature has to be caused by CO2, as if there could not possibly have been some other reason.
    ————————–
    This little blurb on the paper already mentions the positions of the continents having an affect on climate, the albedo of growing sea ice compared to open ocean having an affect on climate, and I’d be surprised if the *actual paper* didn’t mention that the Sun was about 7% fainter (total solar irradiance) back then .
    These are three rather large climate factors, none of which is CO2.
    Climate scientists are well aware that CO2 is just one of many factors affecting Earth’s climate.

  27. There either had to be land near the poles in order to kick this off or it had to be EXTREMELY cold.
    Image the Southern Ocean without Antarctica in it. Sea water on the surface would cool until it sinks. This would pull in more warm water. So you would probably have various gyres where water sinks and they would probably merge at some point to create a colossal whirlpool at the pole. In other words, the ocean would probably do something akin to what the atmosphere of Saturn apparently does. You would need to cool nearly the entire ocean because it would be circulating like mad. The colder it got, the more warm water would get pulled in. The bottom of the ocean would be a general Northerly flow of cold water and the surface would be a generally southerly flow of warm. This would act to pull a lot of heat away from the tropics. I would expect the result to be less extreme temperature difference between the pole and the tropics than we see today with tropical heat relatively quickly transported to the Southern pole where it would radiate away, the water would sink and return Northward.
    In the current Arctic situation, you have a nearly landlocked and relatively shallow ocean. Again, if the North pole had no land nearby, you would have the same mechanism operating there.
    In the situation presented in the article, we might see ice forming on the continental land masses before actual sea ice! Heat is being rapidly transported away from the tropics to the poles which allows more ice to form on mountains in the tropics. As this ice begins to form, the albedo of the planet rises and the sea level begins to fall. Without land to hold sea ice in place or at least keep it corralled in a general location of the pole, it would drift away in summer to warmer water and melt each year. Without land at the pole, I would think it would be extremely difficult to get ice to form at the poles and stay there.
    It seems more likely to me that ice began to form on the temperate mountains and began to spread as temperatures dropped. My guess is that the actually freezing of the ocean would have happened extremely quickly as nearly the entire body of water was cooled to near the freezing point. As sea levels dropped, more land becomes exposed. So the “shorelines” move both North and South closer to the poles. At some point during the winter, ice begins to form along the coastlines. So imagine it is Northern Hemisphere winter. Suddenly the ocean freezes from the Northern coastlines all the way to the pole in an extremely short period of time (couple of weeks). Albedo rapidly increases.
    But I think the point here is that it might have froze from temperate region to pole and not from pole to temperate region if there was no land at either pole and a lot of land distributed around the planet in the tropics. If the oceans were colder than today, it is quite possible for ice to have formed along shorelines in winter as far South as 35N. It can form nearly that far South in winter today. I have seen ice at Lewes, Delaware which is at about 39N. It could then have very quickly covered the entire hemisphere in a matter of several days but it would have frozen from the “edges” toward the “center”, if you will, the same way a lake generally freezes.
    Getting an ocean with no land near the pole to freeze from pole toward the tropics and getting that ice to stay there through the summer is probably not possible.

  28. What makes them so sure the rocks weren’t on the top of a mountain or a tibeten style plateau?

  29. ……………….JFD (19:42:45) :
    Anthony, I am a regular visitor, but primarily a lurker. I appreciate what you do very much. I think that you have done an excellent job of staying on top of the vast amount of rapid fire information since Climategate broke wide open. It has taken plenty of effort to do what you have done. Please be proud of yourself.
    I believe that basic geology is the real key to understanding climate and has been left out of much, if not essentially all, of the climatologists studies. You do a good job of bringing a wide mix of science to your readers.
    ————————————————————-
    JFD: A geologist (so he said) posted a blog entry somewhere on WUWT and said ‘I don’t know any geologists that believe in AGW’. One problem is that Geologists have been left out. THe other problem: Do you know any biologists who don’t believe in AGW? I started with the mutating/disappearing frog they’ll be the last to acknowledge AGW ain’t so because they ‘know’ it is. All these guys getting together for a media blitz are Biologists. Johnnny

  30. Sheffield BM(Smallz79) (19:36:10) : “What really happen [sic] was a world wide flood, in which water came down from the sky and bursted [sic] out of the surface of the Earth all at once. This caused a simultanious [sic] and (comparered [sic] to millions of years) instantaneous movement of all land masses to were [sic] they are presently. This is all completely verifiable, you just have ask the right scientists. Which by the way the Earth is still holding all that water somewhere.”
    And exactly who would those “right scientists” be? Give us their names, please.

  31. One hypothesised trigger for Snowball Earth, which I assume the authors have noted, and which others have indeed noted, is the continental land mass configuration at the time possibly inhibited poleward-moving oceanic circulations transporting equatorial and near-equatorial ocean waters towards the poles.
    Contemporary examples of oceanic circulations moving “oceanic heat” to the poleward regions are of course the Kuroshio, East Australian, Gulf Stream, Brazil, and the Agulhas circulations. And note the contemporary continental configurations – with major N-S oriented continental land mass margins adjacent to large open oceans, which facilitate such circulations. Contrast such a configuration with the inferred continental land mass configurations in the diagram presented by the authors.
    So we should perhaps note continental configurations and their role in constraining or promoting heat transfer from the equatorial oceanic regions to the polar oceanic regions as a possible factor in initiation and termination of snowball earth scenarios.
    These hypotheses are of course not new or original by any means…

  32. Beware the brown bear (which is now white). as AGW forcings are now going to show up in…………………..climatic induced evolution adaptions (I hope Gore doesn’t read over at WUWT as maybe he hasn’t thought of it!)

  33. Regarding the scenario described in the illustration, wouldn’t it be more likely that the “tipping point” driving the planet to total ice coverage would be when the ice advanced enough to dramatically reduce the amount of H2O, the real greenhouse gas, in the atmosphere. And if volcanism ended it, wouldn’t it likely have been through the slow but always positive addition from sea floor geothermal activity building to another tipping point because the ice coverage suppressed the normal heat mixing mechanisms of the oceans. If after 5 million years that heat build up broke through the stratification and attacked the glaciated surface the resulting increase in atmospheric H2O and the oceans dumping heat to return to a more balanced state would account for the developed hothouse Earth and the eventual return to a more equilibrated state, without CO2 doing any more that its usual tag along function.

  34. What a bunch of CO2 as thermostat brainwashing nonsense! As the article says they don’t know what caused the ice age Or why it ended. Those poor climate scientists with their carbon fixated minds. A shift in the earth’s axis easily explains radical changes in climate. Say, maybe thats why the geographical and magnetic poles don’t occupy the same location. Snowball earth, don’t believe it. Fauna sensitive to temperature have survived (i.e. tropical frogs). Honestly, people really do get paid for this stuff?

  35. The Snowball Earth formation:
    How about a really big asteroid hitting Venus at a glancing blow, making a huge cloud that migrates with the Solar Wind blocking a lot of the Sun from heating Earth?
    It’s rotation is backwards with respect to the rest of the Solar System, except for Pluto.

  36. “Because of the high albedo…of ice, climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over,”
    What ocean? The oceans are only 200 million years old at the most. See here
    Reply: You appear to be confusing the age of the current rock on the sea floor with the age of the oceans. These are not the same thing. ~ ctm

  37. “as if the well known “greenhouse” effect “shuts off” at certain levels of atmospheric composition, thus rendering significant additions to those levels, largely moot.”
    That pretty much sums up my position on the topic. Once the level of saturation is reached, no further warming can occur from adding more. Once every last bit of infrared radiation has been absorbed, no possible increase in temperature can occur.

  38. “Anu (20:48:51) : ”
    My statement was based on the image, and I am seeing some people question whether that image was part of the study. So, if it was not part of the study, then my remarks are moot and pointless.

  39. “Holy ice skating on the Amazon River, Batman!”
    “That’s right, Robin. Just keep exhaling and by Tuesday we’ll be roller skating all the way back to Gotham City.”

  40. Anon (20:34:35) :
    “Is there really a desire to figure out what is going on, and what the actual risk levels are, to taking carbon that was sequestered over tens of millions of years and releasing it in what is essentially an almost instantaneous geological time period? ”
    ========
    I’m sorry, but, without releasing carbon, you could not even be asking such silly questions.

  41. Tim McHenry (20:11:13) :
    Studies like this, though speculative, base their findings on well documented field observations that can be readily checked and potentially refuted. Modern climate science ain’t quite so accommodating.
    And anyway, as a geo-nerd, I think Snowball Earth is just plain cool!

  42. If this snowball earth ever occurred the result would be an extreme lack of water vapor available for the creation of a hothouse earth. CO2 by itself would not be sufficient enough to raise the air temperature above freezing. Whatever water vapor was vented by volcanoes would quickly fall as snow either on the land or the frozen oceans. To see how little effect a volcano has on a glacier take a look at the glacier on Mt. Saint Helens that got its start in the late 1980’s and still exists today despite dome building eruptions between 2004-2006. I have read somewhere that even if the atmosphere was 100% carbon-dioxide it would not retain enough heat to reverse a snowball earth without significant water vapor.

  43. What about slowly accumulating ash and pumice on top of the ice? NASA’s recent paper said soot is ten times stronger than GHG’s in melting ice.
    Oh, and Anon, it’s also well known that greenhouses don’t work by blocking infrared radiation. They work by stopping convection.

  44. “Scientists don’t know exactly what caused this glaciation or what ended it…”
    And…….. back to Snowball Earth and Venus.
    How much did that cost?

  45. gary (20:35:20) :
    There are glacial rocks of this age in the tropics, in Australia and Oman for example.
    The continents however, have all moved many times since then.
    Tim (20:54:42) :
    Deposits from high mountains and plateaus are rapidly eroded. There are none preserved that are nearly that old.

  46. Dear anon: you attribute magical properties to CO2, as though it is the only thing that could possibly affect climate. Given the well documented past swings between Ice Age conditions and quasi-tropical conditions, all of which predate human existence, what exactly is the evidence that CO2 is anything more than a bit player in this opera? In my experience, attempting to explain the behavior of a highly complex system in terms of a single variable is an exercise in futility and self-delusion. I will, however, grant that if the sun either goes out or explodes we might have a problem on our hands.

  47. Anon (20:34:35) :
    Why are so many of the commenters here seemingly bent on taking an interesting scientific assessment of the state of the earth three quarters of a billion years ago, and turning it into an otherwise unrelated attack/spin fest against the relevancy of greenhouse gas levels in the current atmosphere?
    It has been this way almost every time one observes this blog.
    Is there really a desire to figure out what is going on, and what the actual risk levels are, to taking carbon that was sequestered over tens of millions of years and releasing it in what is essentially an almost instantaneous geological time period?
    Or is the desire to simply believe, by any means possible, that this simply can not, or likely does not, present much relevancy — as if the well known “greenhouse” effect “shuts off” at certain levels of atmospheric composition, thus rendering significant additions to those levels, largely moot.
    The comments on this blog (as well as the general slant of this widely popular blog itself) seem to support the latter phenomenon being at work here, for more than the former.

    You are laboring under a series of false assumptions, false conclusions, and false beliefs of your own, which can only result in your having false perceptions. For example…
    You talk about “taking carbon that was sequestered over tens of millions of years and releasing it in what is essentially an almost instantaneous geological time period.” Most diamonds are made of carbon, and most diamonds were sequestered in the Earth billions of years ago, not only some mere tens of millions of years ago. You are obviously implying that the age of the fossil fuels and their usage in mass quantities by humans in only the very recent Industrial age is supposed to somehow mean there is an overwhelmingly disproportionate release of carbon dioxide and other gases from these fossil fuels into the atmosphere as a consequence. As any decent geologist can tell you, nothing could be further from the truth and reality.
    The amount of carbon dioxide released by human consumption of fossil fuels is relatively miniscule and insignificant in absolute quantities and in physical effect upon the planetary environment. Nature is the vastly overwhelming factor in all exchanges of carbon dioxide between the planet’s various environments. If it were somehow possible to invoke magic and make it possible for humans to consume all of the remaining reserves of fossilfuels in only one year or one lifetime, the amount of carbon dioxide available in such quantities is utterly incapable of increasing atmospheric levels to those which have existed for the most recent 500 million years. To reach those levels would require the instant vaporization of significant fractions of the Earth’s carbonaceous continental plates by multiple major asteroidal strikes. Human efforts are absurdly puny by contrast. This is why geologists are typically dismissive of AGW claims that absurdly exagerrate the extent to which humans can extract enough hydrocarbons from the Earth to significantly change the atmospheric chemistry.
    You also talk about a “greenhouse effect” in a manner which clearly indicates you do not understand what it is supposed to be or how it is supposed to work. Increasing atmospheric levels of carbon dioxide has a diminishing effect because it cannot have an effect upon energy which has already been removed by other molecules before reaching the additional molecules of carbon dioxide.
    What can be considered normal, meaning average over time, levels of atmospheric carbon dioxide is somewhere around 1200ppm to perhaps 2500ppm. Plant life is presently in a state of carbon dioxide deprivation as a consequence of our experiencing an ice age and the present inter-glacial period of the ice age. If humans were to become extinct tomorrow, the Earth would still naturally come out of the present Quaternary Ice Age some millions of years in the future, and the atmospheric carbon dioxide would naturally return to 1200ppm and greater levels of carbon dioxide in the atmosphere as there was before the Quaternary Ice Age had begun.
    Given all of the varous factors which can and may affect the onset and end of planetary glaciations, the fixation of some investigators on carbon dioxide as the one and only primary causitive agent is instantly suspect. While atmospheric carbon dioxide may ultimately prove to have a key role in such glaciations, failures to relate the other factors as well gives more experienced and knowledgeable readers reason to suspect the authors are knowingly or unknowingly pandering to the current AGW hoax and CO2 mania for whatever reasons having to do with grants, funding, prestige, or whatever else may be motivations.
    As for the so-called risk levels, mammals thrived in atmospheric carbon dioxide levels of 600ppm, 1200ppm, and greater over a period of some thirty million years; so it is up to the people who wish to create an alarm to demonstrate scientifically why mammals generally and humans in particular should be so worried about keping warm and feeding the plant life we all need for survival on this planet.

  48. Volcanos, schmolcanos. If you read the book, The Chilling Stars by Svensmark & Calder, you’ll see they note that the “snowball Earth” episodes within reasonable certainty coincided with heightened rates of star formation & destruction across the entire Galaxy — and hence — a heightened influx of cosmic rays.
    Lord Monckton is fond of noting that during the most recent iceball episode, attributed here to ~715 million years ago, CO2 levels exceeded today’s concentrations several times over.

  49. Why are some of you so negative about this.
    Here are some scientists trying to find out something really cool and interesting about the history of the planet. This is pure science at its best. It is really hard to figure out what the planet was doing that long ago. Don’t knock them.

  50. ” Ian H (22:55:41) :
    Why are some of you so negative about this.
    Here are some scientists trying to find out something really cool and interesting about the history of the planet. This is pure science at its best. It is really hard to figure out what the planet was doing that long ago. Don’t knock them.”
    NOT questioning scientists is what got us into the mess we’re in now…
    Everyone knows that CAGW or CACC is a house of cards, except, of course, the president, the supreme court and the EPA…

  51. I’m sorry, but the word “Models” just blew it for me. I found it interesting and plausible up to that point.
    See what a hoax can do for you?

  52. Douglas Haynes (21:02:29) :
    One hypothesised trigger for Snowball Earth, which I assume the authors have noted, and which others have indeed noted, is the continental land mass configuration at the time possibly inhibited poleward-moving oceanic circulations transporting equatorial and near-equatorial ocean waters towards the poles.

    The ice ages typically occurred while the continental plates where configured as supercontinents mostly in the Southern Hemisphere, particularly astride the South Pole. Glaciation of the North Pole is extremely rare in Earth’s past. Some of the pre-Cambrian ice ages such as the Stuartian event suspected of resulting in a Snowball Earth may have resulted in great part as a consequence of anaerobic lifeforms being supplanted by aerobic lifeforms. They liberated vast quantities of oxygen into the atmosphere for the first time by reducing carbon dioxide levels from a 15 percent of the atmosphere to the present less than one percent levels.

  53. Fine. Personally, I’m worried about my great, great, great, great, great grandchildren and whether or not they’ll have a sustainable habitat to live in. Think globally, act locally! Rock on, we’re saving the planet! Woo-hoo!

  54. I simply don’t buy the role of CO2 melting the icecap in this theory..
    It’s in bed with the AGW theory.
    So, they really have to look for another explanation(s).

  55. Fascinating, if true. Wouldn’t the Earth’s landmasses have to be organized in a particular way for this to happen? Or, at least, be more likely to happen?
    Is there anything else that could explain the observations made by these scientists?
    johnnythelowery (20:59:33) :

    THe other problem: Do you know any biologists who don’t believe in AGW?

    Dusting off my (ancient) biology degree I find myself wondering why biologists would fall for CAGW and all this extinction by CO2 nonsense. Ok, so they believe in AGW, but biologists should be the first to tell you how adaptable life is, shouldn’t they? Shouldn’t biologists be the first group to be laughing at the “CO2 pollution” idea?
    D. Patterson (22:41:35) :

    What can be considered normal, meaning average over time, levels of atmospheric carbon dioxide is somewhere around 1200ppm to perhaps 2500ppm.

    Why would it bounce back to those levels? Hasn’t atmospheric CO2 been steadily declining for many tens of millions of years?

  56. give me a break
    And plate tectonics had nothing to do with it , where were the continents 700 m years ago and where did the ocean currents flow ?
    QED

  57. OK, I am open-minded about the Earth has ever been a snowball – it’s surely plausible and the geological evidence may be fine – but I think that the comments in the first diagram that CO2 greenhouse effect has brought us away from that regime are completely preposterous.
    It is easy to see that CO2 changes in the last 542 million years were only linked to temperature changes by +-5 degrees or so, despite the concentrations’ reaching 4500 ppm (more than 10 times more than today), see
    http://motls.blogspot.com/2009/04/birth-of-oil-geology-temperature-co2.html
    To go from a snowball to a fully melted Earth, you need a warming by 40 °C or much more. It is absolutely inconceivable to achieve this warming with any concentration of CO2 – even if you managed to oxidize all the carbon on the surface of the Earth – because the dependence of the temperature on the concentration is really logarithmic. To change the temperature by 4 °C, you need to increase the CO2 by an order of magnitude, roughly speaking. So you would need ten orders of magnitude of a CO2 increase.
    It’s just a complete nonsense. This paper, seemingly about an abstract purely Academic topic of the climate in geological eons in the distant past, is actually just another contribution to the AGW hysteria, designed as such. It’s a mixture of legitimate science and nonsensical tendentious interpretations that are the main driver of studies produced in this way – and also the main source of the funding for people like Schrag.

  58. “The amount of carbon dioxide released by human consumption of fossil fuels is relatively miniscule and insignificant in absolute quantities and in physical effect upon the planetary environment.”
    Every oil and coal field on the planet, if left alone, would eventually have a volcano erupt through it releasing more CO2 in a day than we might release in a decade.
    All the CO2 in the atmosphere would eventually be turned into coal, oil, limestone, marble, and other forms and life would die if something didn’t come along and return that carbon to the atmosphere.
    It has been hypothesized by many scientists that the demise of Earth will be by CO2 depletion if left to its own devices. Certain types of plants were already having a hard time due to CO2 starvation (gymnosperms were once the dominant type of forest on Earth). As more carbon is locked up in the Earth, the level of CO2 in the atmosphere falls, plant production declines, then animal production declines.
    It has taken Earth over 4 billion years to evolve a species that can take that carbon out of the ground and return it to the atmosphere probably giving and extension to the period that it can support life.
    Then there is the fact that the more CO2 you put into the atmosphere, the faster it is taken out. If you double the atmospheric CO2 currently available to pine trees, they grow four times faster and produce ten times more seeds resulting in an explosion of pine trees. By growing four times faster, I mean they put on four times as much biomass in the same period of time.
    An article in the UK Telegraph reported:

    A study by the University of Leeds, published in the science journal Nature, measured the girth of 70,000 trees across 10 African countries and compared them with similar records made four decades ago.
    On average, the trees were getting bigger faster and researchers found that each hectare of African forest was trapping an extra 0.6 tons of CO2 a year compared with the 1960s.

    There are some 60 million hectares of African forest designated as “forest reserves” which means they are currently absorbing 36 million tons/year more CO2 today than they were in the 1960’s if those figures are correct.
    It has also been learned that global forestation numbers had been distorted by counting only deforestation operations and not considering the amount of new trees growing in places that had previous been farmed. Given a conservative estimate of 3.5 billion hectares of global forest, that would mean they are absorbing 2.1 billion tons of additional CO2 annually today on top of what was already being absorbed in the 1960’s and I haven’t counted increased biomass production from plankton and other aquatic plants.
    The more CO2 you pour into the air, the faster it comes out. Carbon means life. More carbon, more life. More life leads to less carbon as it becomes sequestered and eventually life dies until something comes along to release that carbon again.

  59. “From an evolutionary perspective,” he added, “it’s not always a bad thing for life on Earth to face severe stress.”
    I remember reading an article that hypothesized that life was able to advance beyond simple organic compounds as a result of such a frozen environment. Basically the ice acted as a giant laboratory where simple organic compounds were contained in isolated fissures within the ice. These natural test tubes would then mix with others as the ice shifted and moved about. The end result of which was billions upon billions of random combinations that created more and more complex chains. If conditions were ideal and static these compounds would never have formed more complex versions.
    Maybe we’ve been looking at this debate (or lack thereof) from the wrong perspective. Without the opposing view inducing stress in all of us we wouldn’t be advancing a better understanding of our world because there would be no incentive to.
    So next time you feel like screaming, try thanking an alarmist for ringing the bell at the free market of ideas and may the best theory stand up to the scrutiny.
    JM

  60. Reply: You appear to be confusing the age of the current rock on the sea floor with the age of the oceans. These are not the same thing. ~ ctm

    Hi Charles. I don’t think I’m confused. There is pretty broad agreement as far as I’m aware that the Atlantic Ocean didn’t used to be there and Africa nestled up against South America. So, no Atlantic Ocean > 200mya. That’s all based on the spreading we see along the mid Atlantic ridge. Same thing is happening in the Pacific.
    Reply: No…there is widespread agreement that the current solid rock on the sea floor wasn’t there 200 mya. It is constantly formed at spreading centers and returns to the mantle at subduction zones so after about 200 mya it has all cycled back to the Mantle. There have been oceans, although not necessarily in the same places, for much longer than that, at least according to current continental drift theory and research. Check out the Wilson Cycle. ~ ctm

  61. The BBC reports of 716 million years ago were that in spite of the entire Earth being buried in ice up to and including the equator, it was all caused by man-made carbon dioxide “emissions”, and also proved their assertions that there is “an underlying warming trend”.

  62. How confident are the scientists, that what they say realy happened like this?. Was any one their to see it?.Are they (scientists) 100% sure ,or is their some guess work here to make it fit into some other ideas. Just because a scientist says these things about the past is it realy true?.

  63. Climate History shows a graph of earth swinging between 10 deg C to 25 deg C, compared to the current 15 deg C. (With some spikes to about 28 C.)
    If nature happily endured temperatures 10 C warmer, what’s the big deal over a 1 deg C increase?

  64. We have such a perfect – and unanimous – understanding of our current climate, that we should indeed start to figure out what happened to the climate 700 million years ago. Where is Michael Mann and his tree rings when you really need him? By the way I did not see anybody referring Nir Shaviv’s work who postulated that “Snowball Earth” periods occur when our solar system passes galactic arms with a high density of cosmic rays hitting the the Solar System and of course the Earth. This ties in with Svensmark work who also correlates the density of cosmic ray showers hitting the Earth with the climate. Of course Svensmark looking at the changes in the Sun’s magnetic behavior impacting the incoming density and energy of cosmic rays -and cloud covers and the climate – which are events measured in decades, or centuries- whereas Shaviv is proposing to explain very large climatic changes, “Snowball Earth” events, occurring in timescales of millions of years and typically separated on average more than a hundred million years.

  65. This was published some years ago by the BBC through the open university in the UK. It’s a very poorly researched piece with the same sort of evidence as the current CO² debate.

  66. As Erik has noted, this cooling episode is consistent with the theory laid out by Svensmark and Calder in “The Chilling Stars” that cosmic rays have a major effect on our climate. They enter our atmosphere and form condensation sites for low clouds. The clouds cause cooling by reflecting away sunlight. When our solar system passes through the spiral arms of our galaxy, which happens with a period of about 145 million years, we are subjected to a higher flux of cosmic rays because of greater exposure to supernovae. And sure enough the Earth goes through cooling periods every 145 million years. This Stuartian cooling fits the pattern, although it was very severe.
    [Actually, we pass through spiral arms every 75 million years, though others have cited other numbers, including 30 million years as an explanation for the cycle of mass extinctions. 75 MYr is the most frequent cited number. – Astromod]

  67. Well I don’t believe it because nowhere does it have qualifiers such as “likely” or “very likely”. These are imperitive scientific terms aren’t they? lol

  68. Trying to discover what happened millions of years ago reminds me of the old Zen problem of how to get a goose out of a bottle without injuring the goose or breaking the bottle?
    Things were very different then. Without sufficient factual evidence of what was happening 716.5 million years ago and the ‘context’ of the assumed event, the proposed hypothesis is mere speculation.

  69. greg2213 (23:28:07) :
    D. Patterson (22:41:35) :
    What can be considered normal, meaning average over time, levels of atmospheric carbon dioxide is somewhere around 1200ppm to perhaps 2500ppm.
    Why would it bounce back to those levels? Hasn’t atmospheric CO2 been steadily declining for many tens of millions of years?

    “Tens of millions of years” is a short period of time with respect to the past changes in the Earth’s atmospheric chemical composition. Carbon dioxide has been on a declining trend for about the past 148 million years. This ~148 million year trend is a small segment of the Earth’s more than 4,600 million year past. The Earth’s atmosphere was about 15 percent carbon dioxide in its early period, and life subsequently reduced those levels to below one percent over the past 2 billion years or more.
    Carbon dioxide levels started to rise a very small amount about the time of the K-T boundary and the suspected 9 mile diameter asteroidal impact event. However, the present Quaternary Ice Age began about 30 million years ago (0.65 percent of the Earth’s existence), and the levels continued to decrease overall during this ice age. During the Karoo Ice Age of the Carboniferous, temperatures and carbon dioxide levels plummeted and then increased somewhat after the ice age. During the even earlier Andean-Saharan Ice Age of the Ordovician-Silurian, the temperature plummeted, but the carbon dioxide did not plummet until after the ice age and while the temperatures began to soar again. Nonetheless, carbon dioxide levels increased again, but not to their former levels.
    Carbon dioxide can be expected to return to higher levels than today or even the levels which existed before the Quaternary Ice Age, because they did so after the past ice ages. If life is continuing to change and evolve the chemical composition of the atmosphere as before, perhaps carbon dioxide may never return to levels greater than 600-1000ppm until and unless aerobic life on Earth is extinguished. In any event, past history implies the end of this ice age should result in a substantial increase of carbon dioxide levels.
    Ultimately, extraterrestrial events must extinguish most or virtually all life on the Earth. Without aerobic lifeforms to consume the carbon dioxide, the Earth’s continuing vulcanism must eventually accumulate substantial increases of carbon dioxide in the atmosphere.

  70. Incidentally, I think the diagram should say “increased reflectivity” rather than “lowered reflectivity”.
    Lower reflectivity means more heat absorbed and temperatures increasing.
    While they talk about climate modeels, they don’t say CO2 and to be honest, I don’t see that CO2 has anything to do with it.
    The conjecture is that volcanic activity may have either started or ended the glacial period.
    We are supposed to be thinking here of something like Yellowstone park blowing up…. as I understand it, a one off volcanic event leaves a huge amount of ash and SOX in the atsmopshere at high altitudes which persists long after the event and blocks solar energy and we get a lot of cooling.
    However, and I am assuming this is the thinking, if you get a massive caldera type eruption (the lid blowing off Yellowstone is the next such event but as I recall the event here was something much bigger) then you have huge amounts of ash etc in the atmosphere but continuing volcanic action below. In this case I would imagine the solar energy is mostly blocked and CO2 has litte to do with anything. The heat from volcanic activity would be ongoing and the heat released would be trapped due to that same ash etc. that is blocking solar energy; while solar energy isn’t getting in, volcanic energy isn’t getting out. In either case the effects of CO2 are going to be negligeable compared to the other effects.
    So I can see the potential for volcanic activity being a possible factor eexcept that as the activity subsides, there is still the debris and particulates that persist in the atmosphere after the event blocking solar radiation. If the volcanic activity ceases, then there would be some major cooling. It all depends how hot it got, how long it lasted and so on. Of course, a transeint volcanic event wont’ produce much heating but a long term caldera type event? perhaps the oceean temperature were significantly elevated over time so that termination of volcanic activity would cool the planet but to a comfortable level?
    PS I assume that during this time we would have also been subjected to meteor impacts…. its a long time frame and more debris in the system back then.
    Perhaps some such event either triggered the ice ball (ejector in the atmosphere) or relieved it….. the thermal energy of the impact…. there are all sorts of mechanisms one could propose but the evidence would be slight.
    It depends what evidence they have found or were looking for.
    Meteor impact would be revealed the same way they inferered the Yucatan impact, from ejector material in the sediment, in this case either above or below. Meteor impact could also trigger volcanic events but was there any evidence of significant volcanic activity following Yucatan?
    Did anyone look?
    So far as I can see, the paper discloses evidence of the possible snowball earth and puts a date on it. It doens’t say CO2 has anything to do with anything. It spculates on possible triggers for the feezing and warming. There are lots of possibilities. The importance is that with a date, scientists know where to look in the geologocal records and evaluation of the strata imediately before and after is going to reveal clues to causal effects.

  71. It is theorized that millions of years ago the solar irradiance for was lower than it is now, and this is plausible, based on astronomical observations of other stars in our galaxy. “Theoretical models of the Sun’s development suggest that 3.8 to 2.5 billion years ago, during the Archean period, the Sun was only about 75% as bright as it is today.” [Source: Wikipedia]. A slightly cooler sun itself (“Faint Young Sun” model) can contribute to an earlier cooler earth, however cannot explain “Snowball Earth” as recently as 0.7 billion years ago. What’s left? Rather than theorizing about a diminutive greenhouse gas (CO2), think catastrophic events!
    – Massive volcano activity on the surface of the earth.
    – Collision(s) between earth and asteroid(s) causing the atmosphere to be filled with massive amounts of light blocking & reflecting solid particles (dust).
    – Substantial occlusion of solar radiation outside of the earth’s atmosphere, caused by massive quantities of comets, asteroid fields and /or a dense interstellar gas cloud traversing the solar system.
    What we consider as “catastrophic” is business as usual for the universe, as the smoothness that we observe today in our solar system and elsewhere is in actuality an anomaly in terms of the long term processes that occur over millions of years. This idea has been advanced by Stephen Hawking in his discussion of the “Weak Anthropic Principle” in his book “A Brief History of Time”.

  72. Nowhere in the article above did i find any reference to CO2 and while it may be expected as a result of volcanism, it doesn’t mean that it has a significant effect compared to the other factors. There must be something extreme going on to cause snowball earth.
    It also doesn’t mean that just because we suspect some scientists and others of fudging AGW, we don’t throw out the whole of climate science.
    A snowball earth lasting 5 million years is a major climate event and not just weather.
    It seems quite reasonable that if you get ice extending far enough, sans other factors, then reflectivity will impact severely on the solar radiation budget.
    The problem is to know the causes, what initiated it and what ended it. Major events must also have major causes.
    That doesn’t have anything to do with AGW theories and however much we may think the theories of AGW are a crock, it doesn’t invalidate the entirety of climate science.
    Like a lot of things, the snowball earth conceept has gone through some phases from theory to possibility to probability and now to some good evidence that it did happen and when it happened.
    The sort of volcanic activity needed to have a significant causal effect is going to be massive. The impact of CO2 isn’t going to be a dominat effect and it says nothing about AGW.

  73. I hate to be nitpicky but don’t I get a H/T for suggesting the article? Or did you find it on your own? Or did some one else suggest it first?
    Reply: I dunno. ~ ctm

  74. Dave Wendt (20:34:40) :
    Am I correct in assuming that the illustration was not part of the PR, but added here.

    The illustration was part of the PR.

  75. Thanks for posting this article! I find it very interesting.
    Never before seen a drawing with the land-area as a belt around equator like that.
    hehe.
    No doubt such changes must have a huge impact on climate. Imagine all the big sea-currents we have today, gone.
    No more heat transport from equator and towards the poles.
    And a different level of cosmic rays from space. Yes, its nice on the planet today.Thats why we are here now. We fit in.

  76. BUT, they should have skipped this very unscientific statement;
    “…climate modeling has long predicted that if…”
    They probably felt forced to put it in….otherwise, no grants?
    I have invented a new concept;
    “grant-forcing”, as opposed to water-vapout-forcing.

  77. As CO2 has obtained the (I believe undeserved) status of “usual suspect” for any planetary warming event, I would really like to see if there are any other good theories for what might have caused of the end of the ‘Snowball Earth’ condition.

  78. Nanny-Govt-Sucks
    You need to do a rethink. Charles has it right.
    The ocean floors are recycled at subduction zones. But from time to time slivers of ocean crust get incorporated, by complex faulting, into the edges of the continents. This is what most of the worlds Ophiolite Belts are made from (old oceanic crust). So there is plenty of evidence of ancient oceans that were way older than 200 myr. This has been confirmed by a multitude of independent lines of evidence. Its very tight science (rather unlike some parts of climate science). Further we can also tell how old these areas of ocean were using a variety of radiometric dating techniques. We can tell what types of fish and other sea creatures were about at the time via the associated fossil record. Open up a modern geology textbook for a general introduction.

  79. CROSSPATCH and others,
    We have hashed out on another post the effects of land masses at the poles. According to the geological record (Douglass McDougall, Frozen Earth) the snowball earth episode(s) occurred when the poles were land free.
    Most people, especially climate scientists, equate polar ice build-up with cooling earth. In fact, the opposite it true. Polar ice actually reduces the rate at which the earth loses heat. That is the key… the RATE of cooling. Ask yourself this question. Which pole is currently cooling the earth more, the arctic or the antarctic? The answer is the arctic. Sure, the antarctic is cooler, which is why there is so much confusion. When ice forms on the arctic, not as much heat can be radiated into space, or transferred to the atmosphere then radiated into space. The temperature at the surface is cooler, of course, with ice formation over the water, but this is not the important piece. The net heat balance of the entire planet is maintained with this insulating cap over the warmer water. Please remember that polar ice does not affect the albedo of the earth significantly, because of the tiny sun angle. Just think, how much sun gets reflected off the arctic ice in the winter? Zero. How about in the summer? Very little. The ice at the equator has a much more significant impact on the albedo, and represents a net heat loss. This is why paleo climatologists “blame” the current ice age on the raising of the Himalayas.
    You alluded to these ideas in your post, CROSSPATCH, so I think you will have no problem grasping it. The same cannot be said for the head of the Climate department at my local university. We have gone round and round on this topic, as well as others like positive feedback loops and other ideas that violate the temperature record of Earth’s past.
    (rant): it should be a requirement for all climate scientists to take (and more importantly pass) courses in thermodynamics and engineering process control.

  80. The CO2 Theory in this study is hogwash.
    If the theory were that possibly a meteor struck the ocean and created massive evaporation and water vapour, then I could buy that.
    Our solar system travels through space at a very high rate of speed and our planet rotates in front and sides of the sun. This would make our tiny planet a target 8 months of the year. The distance changes of the sun to planet of our orbit is not ellipical like scientists think. The mass of the sun is constantly moving forward and as we rotate, our planet catches up with the sun. When our plant is in front of the sun, the sun is moving closer to our planet.
    So, if these scientists are correct, our CO2 levels are at the highest in recorded history….hmmm.

  81. Almost all the continents were locked together over the south pole in Supercontinents Rhodinia and Pannotia at the time. The climate scientists do their best to ignore Continental Drift.
    There were two extreme Snowball periods around 715 million years ago and again at 635 million years ago (and at least two others at 2.4 and 2.2 billion years ago).
    What would happen if all the continents were locked together where Antarctica is now.
    So much ice builds up and spreads out across all the land which is now connected that Albedo increases to close to 0.5 (50% of the sunlight is reflected versus 30% today). That is enough to drop the average temperatures to -20C, just the amount needed to freeze over most of the Earth except for the tropics.
    http://www.marathon.uwc.edu/geography/100/rad-te1.gif
    Snowball ends when continental drift breaks apart the Supercontinent and the continents move away from the pole.
    http://en.wikipedia.org/wiki/File:SnowballGeography.gif
    http://www.meteo.mcgill.ca/~tremblay/Courses/ATOC530/Hyde.et.al.Nature.2000.pdf
    CO2 levels were only about 12,000 ppm at the end of the last Snowball 635 million years ago and only about 6,000 ppm during the previous Snowball 715 million years ago (while the GHG theory would have required at least 286,000 ppm or 29% of atmosphere as CO2 to end the Snowballs – or even 2 or 3 times higher than this).
    http://www.snowballearth.org/Bao08.pdf

  82. Complete nonsense!
    James Ussher (1581-1656) Archbishop of Ireland sorted this out a very long time ago.
    The Earth was created on October 23rd, 4004 BC.
    So no snowballs, just AGW.

  83. I’m not sure we know enough about how snow, ice and frost melt, there are definitely other factors than just air temperatures involved; insolation, wind speed and relative humidity seem to be big factors. Crediting CO2 seems a stretch, hoarfrost captures a lot of photons and 5 million years is a long time for subtle effects to accumulate.

  84. Bill Illis (05:40:08)
    The speculation has omitted one gigantic event in the evolution of the atmosphere, the great oxygen catastrophe or Great Oxygenation Event (GOE) of the Huronian Ice Age. The role of oxygen, chemical evolution of the lithospshere and atmosphere, and aerobic lifeforms are being largely disregarded in favor of a far less influential carbon dioxide yet vital chemical component.

  85. Tenuc (01:26:40) :
    Trying to discover what happened millions of years ago reminds me of the old Zen problem of how to get a goose out of a bottle without injuring the goose or breaking the bottle?
    Things were very different then. Without sufficient factual evidence of what was happening 716.5 million years ago and the ‘context’ of the assumed event, the proposed hypothesis is mere speculation.

    Some elements of the hypothesis are and must inherently be speculative. Nonetheless, substantial parts of this hypothesis and similar hypotheses are supported by a large array of well established factual evidence. Dropstones and tilllites in the geological strata indicate glacial conditions. Banded Iron Formations (BIF) provide indications of oxygenation events. Paleomagentic evidence while difficult to obtain without a potential for errors does provide at least one geological formation without the possible errors. Geochemical signatures provide rock solid evidence. Radioisotopic ratios for carbon provide strong indicators. While the evidence is still in the incomplete and early stages of the investigation, what is already known cannot be dismissed as only speculation, because a significant body of the evidence is not speculation at all. Severe ice ages lasting hundreds of millions of years instead of the more recent tens of millions of years certainly did occur. The extent to which those monumental ice ages resulted in a true Snowball Earth or a quasi-Snowball Earth is uncertain, but the research is still in the early stages which can hugely benefit one way or the other from further research and discoveries in the future.

  86. jorgekafkazar (20:59:35) :
    Sheffield BM(Smallz79) (19:36:10) : “What really happen [sic] was a world wide flood, in which water came down from the sky and bursted [sic] out of the surface of the Earth all at once. This caused a simultanious [sic] and (comparered [sic] to millions of years) instantaneous movement of all land masses to were [sic] they are presently. This is all completely verifiable, you just have ask the right scientists. Which by the way the Earth is still holding all that water somewhere.”
    ————————————————————-
    I’ve read something like this before….and i’m not going to reveal my source.
    ‘…………..the Heavens existed and the earth was formed out of water and by water. By these waters also the world of that time was deluged and destroyed….’ (Pete)
    Also, regarding conversion of CO2 to O in early earth…
    ‘….. And ___ said, “Let there be an expanse between the waters to separate water from water.” So ___ made the expanse and separated the water under the expanse from the water above it. And it was so. ___ called the expanse “sky.” And there was evening, and there was morning—the second Age/Epoch. And ___ said, “Let the water under the sky be gathered to one place, and let dry ground appear.” And it was so. ___ called the dry ground “land,” and the gathered waters he called “seas.” And ___ saw that it was good. Then ___ said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds.” And it was so. The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And ___ saw that it was good. And there was evening, and there was morning—the third Age/Epoch………..’
    So, the first living thing according that big book end are vegetation, trees and seed-bearing plants. Ergo-conversion of CO2 to Oxygen. Just wanted to make one aware that this is in there; an itch i had to scratch. My apologies to anyone if this is offensive and understand fully all the arguments why this shouldn’t be here. This is an FYI courtesy posting. Thx

  87. Joe (05:03:57) :
    Perhaps the turbulence it causes as the planet goes “whoosh” past the camera has something to do with it…. I canna slow her down cap’n….

  88. Ref – rbateman (21:41:46) :
    “The Snowball Earth formation:
    How about a really big asteroid hitting Venus..”
    ___________________
    I have a feeling we’ll never know:-)
    Ref – Robert Kral (22:41:33) :
    “attempting to explain the behavior of a highly complex system in terms of a single variable is an exercise in futility and self-delusion.”
    ___________________
    Scientists are people:-)
    Ref – James Mayo (23:55:43) :
    “..next time you feel like screaming, try thanking an alarmist for ringing the bell at the free market of ideas and may the best theory stand up to the scrutiny.”
    ____________________
    True, but we’re rarely able to do that when we get truly emotional:-)
    Footnote: We know so little and we feel so much.

  89. I apologize for being a bit off topic, but with all the reference to CO2, I have had a nagging thought for a week or so… With the concern over fossil fuel, we think it takes 100s of thousands or millions of years to make from old organic material. Okay, so where is all the raw/partially processed fossil fuel? That should be the bulk of what we find if there is indeed an organic component to the process. Lacking an organic component, is there such a thing as ‘fossil’ fuels? There were reports a few years ago of oil wells pumped dry in the past, refilling with oil, thought to be from deeper in the crust. I just can’t rectify zero reports of raw/partially processed oil discovered, with the amount of oil we do find, and then assume it is organic!?
    This has references from 2004:
    http://www.wnd.com/news/article.asp?article_id=38645

  90. nanny_govt_sucks (00:01:42) :
    Reply: You appear to be confusing the age of the current rock on the sea floor with the age of the oceans. These are not the same thing. ~ ctm
    Hi Charles. I don’t think I’m confused. [….]
    The oceans, meaning the waters of the hydrosphere, formed long long before the continents were formed. During the Earth’s first 60 million years, 4650 mya, the oceans of magma, melted rock, cooled until the water vapor in the atmosphere was cool enough to condense out of the atmosphere and fall upon the cooling proto-crust of the Earth. Once the precipitation had begun, the lowest basin terrains quickly filled with these waters to produce the first hydrosphere and oceans of water on the Earth.
    The oldest known rock is from Australia, and it is a 4200 million year old sedimentary rock formed from sandstone. The sandstones were created by water eroding the ancient landscape of the basaltic type proto-crust on its way to the proto-oceans at even earlier dates. By contrast, the silicon rich continents as they are represented today by the continental cratons were not formed until much later after the Late Heavy Bombardment (LHB) about 3800 to 2500 mya, or about 500 million to 1700 million years after the oceans of the hydrosphere came into existence.
    Today’s continental plates represent the silicon rich and lighter weight products of distilling the heavier basaltic crustal material from the Earth’s basaltic upper mantle basaltic proto-crust. Like rafts of lightwieght material floating upon a sea of basalt, the continental plates are surrounded by the ocean waters of the hydrosphere already existing as the present continental plates formed and overrode the earlier crustal basaltic plates. As the earlier basaltic crustal plates were subducted back into the Earth’s mantle, remelted, and resolidified as new basltic crustal plates, major portions of the silicon-rich and lighterweight continental plates escaped subduction and remelting by riding atop the basaltic crusts and mantle.
    As the basaltic proto-crustal plates and later silicon-rich continental plates formed, underwent plate tectonics, and drifted about the top of the mantle, the hydrospere flowed around those plates and into whatever topographic basins they formed in the crust. While the basins holding the oceans of the hydrosphere have come an gone with the changes in the Earth’s crust, the oceans of water in the earth’s hydrosphere have existed for 4200 million years, 4.2 billion years, or longer.

  91. It seems simple to me. Jan Veizer,and Nir Shaviv have written papers that have established a correlation between average temperatures and cosmic ray flux for the past several hundred million years. Svensmark’s theory predicted just such glaciation even though CO2 concentrations were more than ten times higher than they are now. The latest studies seem to confirm Svensmark’s theory and put another nail in the CO2 driven warming thesis.

  92. Charles, others,
    The current continental drift theory like the current AGW theory is full of holes. Any time you hear “consensus” you should know something is wrong, someone is trying to defend their life’s work. Current continental drift theory claims spreading occurs in the Atlantic and subduction occurs in the Pacific. Why? Why no subduction in the Atlantic? Because it is too easy to see that Africa nestles up against South America like a perfect fitting puzzle piece. The same puzzle pieces fit in the Pacific, but it is hard to see because the Pacific is so big. If the puzzle pieces fit, you must acquit, it means spreading, not subduction.
    Fish fossils from > 200mya are found on continental plates in places like Utah. So there were “shallow seas” on the continental plates, but no oceans back then.
    I’m going to drop this now as it seems pretty off topic.

  93. Snowball Earth whether fully realized or not, just shows that Gaia is not necessarily nice. If earthquakes and tsunamis aren’t enough to convince the Believers, then ice ages should do the trick.
    Personally, in my time in the lab, I’ve never seen the universe try for “statically stable”. Dynamically stable, yes, but not statically stable. Oscillations and fractal fluctuations are the order of the day everywhere one looks. If it’s that way on the subatomic scale, the atomic scale, and micro scale, why should it be different at macro scale?
    Personally, I think our climate is a complex interaction between Sun, cosmic rays, the Moon, and our oceans.

  94. Kevin (19:55:51) :
    How are they so sure that a stop in the Ocean CO2 cycle supposedly leading to a buildup of atmospheric CO2 due to volcanic offgassing caused a ‘hothouse Earth’ effect?

    Because Al Gore said so!
    It’s amazing to me that the scientists related all of the offgassing of volcanoes to C02. They completely left out sulfur dioxide and a host of other more prominent gasses.

  95. “Okay, so where is all the raw/partially processed fossil fuel? That should be the bulk of what we find if there is indeed an organic component to the process.”
    It is called “bituminous shale” and is indeed vastly more common than oil.

  96. JMANON (02:08:24) :
    The references from CO2 in the discussion do not arise from the paper itself, but from other sources like Wikipedia and other papers on snowball earth which specifically do reference CO2 as the primary agent that forced the end of the glaciation of the entire globe. It seems to me that it is appropriate to bring this into the discussion as this would be the information most likely fed to the media – and certainly fed to anyone casually looking up the phenomenon (i.e. Wikipedia) – and which I encountered in a book I am reviewing on microbiology, which discusses both the roles of volcanic CO2 and microbes in ending this extreme glaciation.
    There are, then, two issues here: 1) is snowball earth a plausible theory based on sound geological evidence? – and – 2) what plausible mechanisms could have caused and ended this state?

  97. D. Patterson (07:31:12) :
    Perhaps the turbulence it causes as the planet goes “whoosh” past the camera has something to do with it…. I canna slow her down cap’n….
    Good point.
    But if it were to be a close hit, then it would pull some of the atmosphere away and create massive wind that would erode the land masses.
    It could have also been a near miss from a solar flare. This would have heated the gases in the atmosphere triggering this planets defences which is to change the salinity in the oceans. The atmosphere is very elastistic and any increase in pressure (heat can change a gases density and movement(resonating vibration))exerts out at the atmosphere. It also changes the density of the atmosphere which would change the speed the atmosphere is moving at differing layers.

  98. nanny_govt_sucks (09:43:06) :
    Charles, others,
    The current continental drift theory like the current AGW theory is full of holes. Any time you hear “consensus” you should know something is wrong, someone is trying to defend their life’s work. Current continental drift theory claims spreading occurs in the Atlantic and subduction occurs in the Pacific. Why? Why no subduction in the Atlantic?
    [….]

    The holes are in the arguments which are ignorant or ignore basic facts and mechanisms explaining the continental drift. For example, you ask, “Why no subduction in the Atlantic?” Answer, there are subduction zones in the Atlantic Ocean basins. Consequently, your question and dependent assumptions are invalid. In anticipation of a possible followup question you may have, “Why are there not as many subduction zones in the Atlantic Oceans as there are in the Pacific Ocean?” Answer, it has to do with the nature of the formation of the Atlantic Ocean basins, various mechanisms like retreating subduction zones, tectonic uplift in the oceanic basin, and a number of other factors which differ in effect between the Atlantic and Pacific Oceans.
    Don’t let the bafflegabbers fool you. Continental drift is quite real.

  99. Ref – Al Gore’s Brother (10:20:38) :
    Kevin (19:55:51) :
    “How are they so sure that a stop in the Ocean CO2 cycle supposedly leading to a buildup of atmospheric CO2 due to volcanic offgassing caused a ‘hothouse Earth’ effect?
    “Because Al Gore said so!
    “It’s amazing to me that the scientists…”
    ________________________
    People, including most ‘psyentists’ –and even a number of Scientists– have to (aka ‘must’) believe in something other than themselves. We know so little and want to know so much. When we get a snippit of truth we generally tend to build a story (aka ‘rational explaination’) about how it happened.

  100. M. Simon (02:22:39) :
    Dave Wendt (20:34:40) :
    Am I correct in assuming that the illustration was not part of the PR, but added here.
    The illustration was part of the PR.
    It’s not included in the linked statement posted at Harvard Science or at any of the links in the statement. The graphic includes this link to its origin at the University of Georgia.
    From the University of Georgia Tutorial on Terrestrial Atmosphere: http://www.physast.uga.edu/~jss/1010/ch10/ovhd.html
    Perhaps the mods could clarify the situation.

  101. 6 03 2010 Joe (05:03:57) :
    The near side of the moon has more craters than the far side. Why? Best guess is that the earth’s gravity attracts astroids, bending their path so that they more likely to collide with the moon, on the side facing the earth. Gravitic lensing, sort of.

  102. Glacial ice may have extended to the equator at one time, but marsupial fossils are found in the mountains of Antarctica. Has no one ever heard of Plate Tectonics or is it to be presumed kangaroos like ice for dinner.

  103. rocksandirt (14:01:56) :
    Glacial ice may have extended to the equator at one time, but marsupial fossils are found in the mountains of Antarctica. Has no one ever heard of Plate Tectonics or is it to be presumed kangaroos like ice for dinner.

    What do marsupials in Antarctica less than 2.5 million years ago have to do with the proposed Snowball Earth events of the Sturtian-Varangian Ice Age/s and the Huronian Ice Age 600 million to 2,400 million years ago (2.4 billion years ago)? You’re talking about protozoan lifeforms at the time of the Snowball Earth events with vertebrate lifeforms still in the far far distant future.

  104. Al Gore’s Brother (10:20:38) :
    It’s amazing to me that the scientists related all of the offgassing of volcanoes to C02. They completely left out sulfur dioxide and a host of other more prominent gasses.
    ———–
    It would be less amazing if you looked at how actual scientists treat volcanic eruptions in their climate models:
    http://earthobservatory.nasa.gov/Features/GlobalWarming/global_warming_update4.php
    Volcanic particles, volcanic gases pumped high into the atmosphere where they interact with water vapor to form a reflective shade of aerosol particles…
    The above example is climate modeling of the Mt. Pinatubo eruption in 1991 in the Phillipines. The global circulation model closely matched the observed cooling of about four years duration.

  105. What about the known brightening of the sun and axis tilt? I recently heard a prediction that the continued brightening of the sun (10%/billion years) will fry the Earth, given everything remains the same, within 500 million years. Take that back, put in a different continental configuration and … you don’t need CO2. Volcanic Ash covering glaciated areas near the equator? … another proven ice melter at marginal temps.
    Whatever. I find Snowball Earth evidence amazing even though the forcing mechanisms suggested here and in a BBC documentary and others espousing this theory play too hard for anthrocentric sympathies. I guess its too much to ask for them for ‘Just the facts, Maam’. Its hard enough, given the time scales, to even scratch considering what we, as a species, might be before any of this is meaningful to us in general. Would ‘The Borg Collective’ care?

  106. Phillep Harding (13:39:06) :
    6 03 2010 Joe (05:03:57) :
    The near side of the moon has more craters than the far side. Why? Best guess is that the earth’s gravity attracts astroids, bending their path so that they more likely to collide with the moon, on the side facing the earth. Gravitic lensing, sort of.

    How do you figure the near side with its extensive maria has more craters than the far side with its extensive cratering in the older highlands?

  107. len (15:37:23) :
    Some estimates indicate a 10 percent increase in Solar luminosity in about 1.1 billion years or 1100 million years. By that time the atomosphere and its water vaopr are being stripped from the Earth by the Sun, and by 4.4 billion or 4400 million years the Earth’s hydrosphere has been vaporized and is being stripped from the Earth and blown by the Solar Winds to the outer reaches of the Solar System. Since the Sun is losing mass at an exorbitant rate, the new orbits of the Earth take it to 1.2AU and !.4AU farther away from the Sun near the present day orbit of Mars.
    At 5.56 billion years or 5500 million ears, a member of the WWF lands on the tortured Earth’s bleak landscape long enough to spray paint a message on a nearby boulder where Colorado Springs once stood saying ” I told you so!” After the WWF activist leaves, a prospector survey team rolls up to the boulder in a special purpose survey vehicle. A prospector gets out in his environmental suit and spray paints underneath the first message, “What took you so long, Al baby?”

  108. D. Patterson (07:27:17) :
    Tenuc (01:26:40) :
    Trying to discover what happened millions of years ago reminds me of the old Zen problem of how to get a goose out of a bottle without injuring the goose or breaking the bottle?
    Things were very different then. Without sufficient factual evidence of what was happening 716.5 million years ago and the ‘context’ of the assumed event, the proposed hypothesis is mere speculation.
    “Some elements of the hypothesis are and must inherently be speculative. Nonetheless, substantial parts of this hypothesis and similar hypotheses are supported by a large array of well established factual evidence.
    The computer models show that once 50% of the Earth is covered in ice, the remaining oceans will ‘enevitably’ freeze over. However, these models are working with a limited amount of data, some of which is of dubious quality, and many assumptions are made regarding conditions on Earth some 0.75m years ago.
    We know that there have been many periods of glaciation, some very long, but it is still speculation to posit a that a completely ‘snowball Earth’ actually happened.
    The following quote from the article by the lead author, Francis Macdonald, indicates that the new evidence supports the hypothesis, but does not give conclusive confirmation.
    “Because of the high albedo [light reflection] of ice, climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over,” Macdonald said. “So our result implies quite strongly that ice would have been found at all latitudes during the Sturtian glaciation.”
    “Scientists don’t know exactly what caused this glaciation or what ended it, but Macdonald says its age of 716.5 million years closely matches the age of a large igneous province stretching more than 930 miles from Alaska to Ellesmere Island in far northeastern Canada. This coincidence could mean the glaciation was either precipitated or terminated by volcanic activity.”

  109. Fred Souder (04:59:58) :
    I dismissed the AGW hypothesis way back in the 70’s although my background is more in electro-mechanical engineering.
    I did a sort of “that’ll never fly” & never considered it again until I suddenly found out that some people thought it would fly.
    Sometime last year I hypothesised that the North Pole was one of the thermostats of the Earth because ice loss would allow extra heat to escape to the atmosphere & thence to space.
    Your posting seems to confirm what I thought.
    Do you have a reference I can use please?
    DaveE.

  110. There are many things that strike me as missing in the current theory. I can accept the general outline of an unknown event causing a gradual glaciation through albedo change. I can also accept that once water vapour disappeared, nights would become much colder (i.e. just like a desert night) – what I find is glossed over is how long this lasted.
    Let’s face it – after even a couple of thousand years of no precipitation, and constant vulcanism, the top layer of ice would be indistinguishable from dirty black. And although desert nights are tremdously cool, desert days are blisteringly hot. With no open water to evaporate to form clouds, there would be no shielding from this. Open water would form, albedo would change once more and the earth would return to normal quite quickly.
    What seems more likely to me, is that some event stripped away part of the atmosphere, such that the adiabatic lapse rate became a distant memory. It was only the planet outgassing, and gradually building up air pressure again that caused the ice to melt. It was the air pressure – the fact the was a lot of CO2 in it was just co-incidental.
    Five million years would be about right for that – we do have a lot of atmosphere.

  111. Wow, another ‘theory’ based upon that nasty gas CO2 – as if it is the ONLY gas around – The Universal gas!
    Are these Scientist really that moronic – they continue to embarrass themselves.
    Not only does CO2 cause heat (NOT) but it also causes cold (NOT) and for good measure it also feeds plants – which we need to survive.
    The morons at the EPA have really stepped in it again – first their moron director outlawed DDT and caused 60 million to die.
    Now they are trying to starve us to death – time for all of these twits to the gallows – or maybe? no!

  112. Phillep Harding (13:39:06) :
    The near side of the moon has more craters than the far side. Why? Best guess is that the earth’s gravity attracts asteroids, bending their path so that they more likely to collide with the moon, on the side facing the earth. Gravitic lensing, sort of.
    I sort of have a problem with that as the speed of meteors would impact before gravity can pull the trajectory. Going past may bend it slightly but it would have to be grazing the moon.
    The moon at one time was also a rotational body slowing by the friction of our atmosphere, gravity (and a biggie) magnetic field.

  113. While I’m not exactly sure of the time lines involved, isn’t it possible that the continents were in different locations 716 million years ago.
    Also there is the effect of the Moon: it’s currently moving away from the Earth at about 1-1/2 inches per year. Has any one extrapolated what the position of the Moon was 716 million years ago, and any effect it may have had on Earth’s climate?
    As to the magnetic similarities of distant locals, isn’t it a fact that the Earth’s magnetic field has shifted numerous time over that 716 million years?
    One thing I’ve learned from reading articles on this, and even some “alarmist” websites is that the more we learn, the more we realize how much we don’t know. I think that it would be safe to say that that portion of “the science is settled”.

  114. Rascal (19:42:54) :
    While I’m not exactly sure of the time lines involved, isn’t it possible that the continents were in different locations 716 million years ago.

    All of the hypotheses regarding a Snowball Earth are based upon the locations of the continents being appropriate for the time period being investigated. So, yes, the Snowball hypothese include plate tectonics.

    Also there is the effect of the Moon: it’s currently moving away from the Earth at about 1-1/2 inches per year. Has any one extrapolated what the position of the Moon was 716 million years ago, and any effect it may have had on Earth’s climate?

    Yes, and not only was there a greater lunar tidal effect upon the Earth, the Lunar orbital period was different and the Earth’s diurnal perod was much shorter, making the days and nights much shorter.

    As to the magnetic similarities of distant locals, isn’t it a fact that the Earth’s magnetic field has shifted numerous time over that 716 million years?
    One thing I’ve learned from reading articles on this, and even some “alarmist” websites is that the more we learn, the more we realize how much we don’t know. I think that it would be safe to say that that portion of “the science is settled”.

    Yes, the Earth’s paleomagnetic pole has been shifting, which has been one of the problems with interpreting paleomagnetic data supporting the various Snowball Earth hypotheses. Some critics have even suggested natural events which could have caused the paleomagnetic data to be reset, and one has suggested ways in which the Earth’s magnetic pole could have been a West Pole. There is at least one geological formation in Australia, however, which is claimed to have been free of the circumstances in which the paleomagnetic data could have been naturally reset or set in the wrong direction. So, the hypotheses have survived at least that challenge, so far.

  115. Scientists don’t know exactly what caused this glaciation or what ended it…
    So how come there is a graphic above it from a published textbook (Pearson Publishing?), I presume, that shows exactly what these scientists don’t know? Wasn’t there a Supreme Court case involving the young-Earthers and science that got science like that thrown out of the school system? You know the kind you put in textbooks even though there is no evidence? Addison-Wesley, you should be ashamed. Of course, given the ‘humanities’ textbook I just suffered through published by the parent company, Pearson, I can only display a profound lack of shock.

  116. Apologies ctm, I did not see the other posts relating to the young-earth subject, my point was really more about unsubstantiated science in textbooks rather than some religious point or conversation.

  117. Tenuc (16:18:06) :
    Just remember to distinguish between the well proven elements and evidence of the various Snowball Earth and ice age hypotheses versus those elements which are not well proven or supportive at all. In other words, don’t throw the baby out with the bathwater.
    The computer modeling and the possible overstatement of carbon dioxide as an agent of change may or may not be part of the bathwater which needs to be thrown out?

  118. The cause could have been many things; it’s possible that the sun went through a cold cycle. But i think what’s more interesting than the cause of iceball earth was it’s end – once the earth is frozen over, given the high albedo ever and the lack of moisture in the air (too cold), how does it end? What mechanism could cause the earth to warm up enough again to melt all of that? Since in our experience volcanic activity seems to have a cooling effect, not a warming one, I don’t think that’s a viable mechanism.
    I’m curious for scientific ideas you all may have – was was this system not at equilibrium? Why was it unstable?

  119. I betcha, on a snowball earth, it would get cold enough to snow out all the CO2, at least at the poles. Then when it warms up all that CO2 releases at once and the overdose finally ends up as carbonate rock layers.

  120. If the idea of a totally frozen Snowball Earth seems unlikely, then consider the example of Europa – one of the Snowball Moons of Jupiter.
    Points of interest:-
    Europa has an extremely tenuous atmosphere consisting of almost 100% oxygen gas.
    Europa is covered with young ice, 50 million years old on average, with a high albedo (whiteness) and low number of asteroid impact craters.
    This young age implies either an ice rafting surface repair process or a free water surface (albeit briefly) at a geological time equivalent to the Eocene Epoch on Earth.
    (For Europe read Europa in this Google Translated link from the original Spanish text http://singularidad.wordpress.com/2007/02/20/proximo-destino-europa/ )

  121. Ref – Anu (15:25:44) :
    http://earthobservatory.nasa.gov/Features/GlobalWarming/global_warming_update4.php
    “The above example is climate modeling of the Mt. Pinatubo eruption in 1991 in the Phillipines. The global circulation model closely matched the observed cooling of about four years duration.”
    _______________________
    (Half serious)
    It seems fairly obvious from your example that, should Global Warming (and/or over-population) ever become be real problem and not just a way for Gore & Co., Inc., to make a bundle, we only have to detonate the Yellowstone Super Volcano to cool things off for another 5-10 million years.
    (Serious)
    I guess my bigest problem with Fat Albert and his friends is Fat Albert and his friends.

  122. tty (10:23:08) : Thank you, Just couldn’t come up with what oil-in-process would be.

  123. D. Patterson (01:40:08)
    You mention the Ordovician-Silurian ice age, which was severe if not necessarily a snowball-earth. Your posting helpfully puts in long term perspective the fluctuating global CO2 level.
    Some interesting features of this glaciation relate to the CO2-AGW debate:
    1. CO2 levels were 8-20 times higher than at present during the Ordovician
    2. Instead of causing runaway global warming, the Ordovician era ended with the severe (Andean-Saharan) ice age.
    3. What about high CO2 being the cause of ocean acidification and death of corals? The exact opposite happened – corals evolved during the Ordovician.
    http://www.palaeos.com/Paleozoic/Ordovician/Ordovician.htm
    These facts destroy the idea of CO2 rising from present very low levels causing catastrophic warming (plus coral-killing). But the “scientific” community is able to blissfully and serenely ignore them.
    A recent thread referred to a paper by Dana Royer using palaeoclimate to examine CO2-temperature climate sensitivity.
    http://wattsupwiththat.com/2010/02/15/paleo-tagging-past-climate-sensitivity/
    CO2-AGW was the unquestioned orthodoxy and paradigm of the paper. The author was obviously in terror of questioning this orthodoxy. Somehow these inconvenient details of the Ordovician, CO2 corals, ice age etc. were ignored. CO2-AGW sailed on unscathed.
    Wonderful thing this peer-reviewed scientific literature.

  124. Arrived late, enjoyed this post and the comments. Glad to see so many others took up my thought: it’s the volcanic ash and soot that darkened the ice, reduced albedo, absorbed solar heat and melted the ice. CO2 has nothing to do with it.
    So, what caused the volcanoes? Probably the stress on the earth’s crust where thick ice sheets build up. A self-regulating system.

  125. phlogiston (06:23:08) :
    The Ordovician/Silurian ice age which lasted from 460 Mya to about 420 Mya and then the Carboniferous ice age which lasted from about 350 Mya to 300 Mya is understood with this map of the continental drift of Gondwana from the NCDC (keeping in mind large parts of the continent were below sea level for parts of the overall period and consequently glaciers could not build up – just sea ice).
    http://www.ncdc.noaa.gov/paleo/ctl/images/figure05_10.jpg

  126. I have trouble getting past the question of where additional atmospheric CO2 came from when the planet was totally enveloped in ice. Are there any proxies from which to quantify atmospheric CO2 at that time? If the CO2 level was constant, what were the heat sources that melted the snowball?

  127. Bill Illis (09:35:30) :
    [….]
    The Ordovician/Silurian ice age which lasted from 460 Mya to about 420 Mya and then the Carboniferous ice age which lasted from about 350 Mya to 300 Mya is understood with this map of the continental drift of Gondwana from the NCDC (keeping in mind large parts of the continent were below sea level for parts of the overall period and consequently glaciers could not build up – just sea ice).

    It was large parts of Laurentia (North American plate), Siberia, and Baltica which had a majority of their areas covered by epi-continental seas, because much of the continents were below sea level during the highstand of the oceans during the Early and Middle Ordovician Epochs. Laurentia was at this time astride the equator and enjoying arid, tropical, and warm temperate climates. There certainly were no glacial ice caps in Laurentia or neighboring Baltica or Siberia during the Ordovician and Silurian Periods.
    There was, however, a major glacial ice cap across the southernmost regions of Gondwana astride the South Pole during the Middle Ordovician Epoch, Late Ordivician Epoch, and early epochs/s of the Silurian Period.
    During the Early Ordovician epoch, the Gondwana supercontinent was in movement from one side of the Southern Hemisphere to the other side while passing nearby the South Pole. Marginal areas of the South American and African plates comprising part of Gondwana actually crossed the South Pole. During the Early Ordivician Epoch these areas of the South American and African plates of Gondwana had some epi-continental seas and seaways as a consequence of the highstand of the oceans during this warm period and nearby convergent subduction zones. Gondwana’s area of epi-continental seas within the Antarctic Circle were a very minor part of Gondwana and the South American and African plates in this region. The very large regions of Gondwana which were flooded with major epi-continental seas and seaways were astride the temperate mid-latitudes and tropical equatorial latitudes. The climate of Gondwana’s South American and African plates located within the high latitude areas of the Antarctic Circle were experiencing a cool temperate climate with no glacial icecaps to worry about. At this time there was no ice age and no glacial ice caps at the South Pole or anywhere else in the world.
    The Saharan-Andean Ice Age developed during the Middle and Late Ordovician Epochs. At this time Gondwana had a small part of its continental shoreline astride the South Pole. The epi-continental sea was very narrow and small. As the cold climate of the ice age developed, the former highstand of the ocean sea levels receded to a very lowstand. The declines in sea levels reduced and in some cases extinguished many of the world’s epi-continental seas. There was only a very trivial fraction of Gondwana’s landmass located in the high latitudes which remained flooded by epi-continental seas and seaways. The icecap had nearly all of the landmass of the world’s largest supercontinent of the period upon which to form and grow. Since the South Pole was located just inshore of Gondwana’s seacoast, The glacial icecap extended its ice sheets over the sea adjacent to Gondwana’s coastline. However, these ice sheets extended from the above sea level terrain within the high latitudws of a supercontinent that otherwise extended overall from the equator on one side of the world and across the South Polar region to the equator on the opposite side of the world.
    During the early epochs of the Silurian Period, the ice age waned and ended altogether. The icecap first retreated to a fraction of its former extent it had during the Late Ordovician Epoch. The edge of the icesheet and icecap closest to Gondwana’s seacoast retreated to a point where it half-covered a large epi-continental sea created by Gondwana’s slight movement northwards as the vast bulk of the Supercontinent continued its movement to the other side of the world while passing nearby the South Pole. Two arms of the shoreline nearly enclosed the epi-continental sea on the north side. The edge of the icecap crossed the middle of this sea. The South Pole was located just inshore on the southern edge of this sea. Just as Greenland is a chain of islands and portions of the Antarctic continent of today is also below sea level, the icecap a mile thick or more flowed from shore into these basins, displacing the shallow epicontinental seas until the icecaps melted.
    The icecap of the Saharan-Andean Ice Age had most of the above sea level terrain of a supercontinent on which to form, grow, and persist. Saying “glaciers could not build up – just sea ice” is simply and utterly wrong.

  128. Could some one recommend a good basic primer on earths geological and climate history for the non scientist reader? I am interested in planetary formation, continental formation, glaciation, volcanoes, etc… For example I seen references to 6 periods of glaciation as well as to 16? What gives? Creationists please don’t respond. Thanks

  129. jim (14:59:52) :
    The approximately six ice ages are subdivided into glacial periods, inter-glacial periods, and other types of periods. The glacial periods are themselves divided into lesser periods.
    The Earth is estimated to be about 4.6 billion or 4600 million years old. The Earth’s atmosphere started out with a composition of about 80 percent carbon dioxide. This overwhelming predominance of carbon dioxide in the Earth’s original atmsophere has undergone a dramtic decrease to far less than 1 percent of the atmosphere.
    Earth’s original atmosphere did not have any significant oxygen. At the time of the first great ice age, the Huronian Ice Age about 2.4 billion or 2400 million years ago, the composition of the Earth’s atmosphere was still 0 percent. It wasn’t until 2 billion or 2000 million years ago that oxygen became a non-trivial percentage of the Earth’s atmosphere, rising to the present approximately 20 percent levels.
    Hypotheses concerning the origins of the Huronian, Stuartian-Varangian, and Saharan-Andean Ice Ages often consider the roles of oxygen, carbon dioxide, and aerobic lifeforms as agents in causing the ice ages. The weathering of terrestrial landscapes and the evolution of aerobic lifeforms are often considered as the reason for the development of an oxygen rich atmosphere and massive declines in atmospheric carbon dioxide, which in turn are considered for their roles in causing the Huronian Ica Age. Likewise, the invasion of plant life upon the terrestrial landscape and proliferation of early trees in the Devonian are considered for their possible roles in radically changing atmospheric chemistry in oxygen, carbon dioxide, and nitrogen, thereby playing some role in triggering the Saharan-Andean Ice Ages.
    In other words, geochemical processes and biological processes are deemed to be responsible for the radical chemical evolution of the earth’s atmosphere.

  130. vigilantfish,
    Thanks for the heads up.
    Interesting.
    Interesting that a number of commentators here have laid into this article as if the authors are advocating significant CO2 influences on snowball earth conditions and even more interesting that the authors have made no reference to CO2 influences.
    It has been interesting to note the way authors have written papers either purporting to suport the AGW case, if the evidence suggests it is consistent with AGW, or declaring that their study doesn’t actually contradict the AGW theory even though the evidence of their work appears to.
    We had a paper here recently in which the authors felt obliged to say that the USA was not the whole world and the data was possibly indicative of a regional anomaly or some such.
    As we move forward from climategate it would be interesting to see to what extent authors feel free not to have to make their work seem either to support or not actually contradict AGW.
    Is this paper a sign of the times?

  131. Heh, I love the creationism. Tough to have any understanding of climate, geology, or the bulk of science that involves time if you believe in world wide floods and creationism.
    Thanks for the chuckles.

  132. “This is the first time that the Sturtian glaciation [the name for that ice age] has been shown to have occurred at tropical latitudes, providing direct evidence that this particular glaciation was a ‘snowball Earth’ event,”
    Fascinating!
    Plus, I read several years ago that, prior to 550 million years ago, on three or four occasions, the Earth was so hot that all the water vaporized. (Or perhaps this was just a theory …?)
    I’m off to try Kwik’s innovation of “grant-forcing”. How’s this for an intro:
    “Carbon Dioxide is eeeevil. We must stomp it out ruthlessly …”

  133. <<>>
    I will recommend something else that you should love reading. It is the book, The Chilling Stars, by Svensmark and Calder. They describe a new theory that explains our climate history far better than any other factor. The theory came from the observation that showed that cosmic rays play a role in cloud creation. You can read a general explanation if you hit the download button at the link below.
    http://www.scribd.com/doc/338170/svensmark-2007cosmoclimatology
    If you like what is in the article I recommend the book very highly. The CRF explains the findings of very diverse disciplines and ties them in together.
    It is interesting to note that the CRF theory predicted that there should have been glaciation during the periods in question and explains the faint sun paradox in ways that CO2 levels cannot. If you read the book you will never accept the false arguments from the AGW side again.

  134. Thanks for the thoughtful responses. I am now reading Popper and Kuhn, after your “post normal science” debates of the last few weeks. There is never a shortage of interesting and challenging subjects on WUWT. I live in a drained glacial lake bed which is now some of the most productive farm land in the world. We have much more to fear from cooling than from warming.

  135. phlogiston (20:59:21) :
    It is hypothesized that a too nearby Gamma Ray Burst (GRB) would create a nitrous oxide smog as it destroyed the ozone layer. The nitrous oxide would soon rain out as acid rain, but the damage caused by UV-B from the Sun would already extensively damage DNA and temperatures would plummet. There is an interesting article on GRBs and an illustration of the effects upon the Earth. See:
    Gamma-Ray Bursts – Putting It All Together
    http://astronomyonline.org/cosmology/grbs.asp?cate=cosmology&subcate=grbs
    (remove the spurious carriage return after the question mark)
    Finding evidence of the GRBs in the geological periods may be a special challenge? Gamma ray traces are already being used extensively in geology to identify rock facies and more. Finding evidence of a particular ET source in the geological record may prove to be difficult. FWIW, the Apollo missions discovered unexpected sources of radiation on the Lunar Farside as they were orbiting above the Lunar surface surveying it with photography and a variety of instruments. I don’t recall the details now, but it does highlight how daunting a task it may prove to be to isolate a particular signal for GRBs.

  136. <<>>
    This makes no sense. Ozone is created when ultraviolet radiation hits oxygen molecules and causes them to split into two free oxygen atoms, which then combine with O2 to form O3. The ozone layer is constantly being destroyed and replenished so any effect due to a temporary nitrous oxide formation would be limited.

  137. Vangel (05:07:40) :
    This makes no sense. [….]

    Use a search engine with the search terms “ozone layer” “and “nitrous oxide”, but be careful to stand back when the results come tumbling out. Everyone in the green community from the IPCC, EPA, UK Environment Agency, WWF, Greepeace, BBC, NPR, and so much more flood the Internet and mainstream news media with reports about the dangers of NO(x) emissions destroying the Ozone Layer.
    See for example:

    NOAA Study Shows Nitrous Oxide Now Top Ozone-Depleting Emission
    August 27, 2009
    The study, authored by A.R. Ravishankara, J.S. Daniel and Robert W. Portmann of NOAA’s Earth System Research Laboratory (ESRL) chemical sciences division, appears online today in the journal Science.
    http://www.noaanews.noaa.gov/stories2009/20090827_ozone.html
    A. R. Ravishankara, John S. Daniel, Robert W. Portmann; Nitrous Oxide (N2O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century; http://www.sciencemag.org SCIENCE VOL 326 2 OCTOBER 2009.
    By comparing the ozone depletion potential–weighted anthropogenic emissions of N2O with those of other ozone-depleting substances, we show that N2O emission currently is the single most important ozone-depleting emission and is expected to remain the largest throughout the 21st century. N2O is unregulated by the Montreal Protocol. Limiting future N2O emissions would enhance the recovery of the ozone layer from its depleted state and would also reduce the anthropogenic forcing of the climate system, representing a win-win for both ozone and climate.
    [….]
    Through the work of Crutzen (5) and Johnston (6), nitrogen oxides (NOx = NO + NO2) are also known to catalytically destroy ozone via
    NO + O3 → NO2 + O2
    O + NO2 → NO + O2
    net: O + O3 → 2O2
    P. J. Crutzen, Q. J. R. Meteorol. Soc. 96, 320 (1970).
    H. Johnston, Science 173, 517 (1971).
    http://www.sciencemag.org/cgi/rapidpdf/326/5949/123.pdf?ijkey=gkBXN.9.4TA2E&keytype=ref&siteid=sci

  138. In reply to Steve Keohane,
    There is apparently no “missing link” between vegetation and crude oil, therefore it appears to be highly unlikely that crude oil comes from vegetation or animals or whatever.
    There are 2 possibilities:
    There was a truly bizzare event millions or even billions of years ago that caused the formation of “fossil fuels” and then stopped, and therefore the supply of such fuels is finite;
    or
    “Fossil fuel” production has nothing to do with decomposition of organic matter, and is an on-going process, but we are unsure of the rate at which the process happens, so we don’t really know if we are using it up faster than it is being produced or not.
    I realize that limiting it to 2 possibilities is overly simplistic, but it would certainly SEEM that if oil came from some process of organic decomposition we would at least be able to see evidence of the process happening or be able to duplicate the process in a laboratory setting. As far as I know, they can (on a very small scale) duplicate abiogenic oil formation in a laboratory setting, but I have never seen anything on biogenic oil formation (if there even is such a thing) being duplicated in a laboratory setting. I am sure that someone will correct me if that is a wrong impression.

  139. D. Patterson,
    The study talks about N2O, and then your equations only show NO and NO2, neither of which are N2O. How would N2O behave?
    I know that near ground level, organic compounds and NO/NO2 (also known as NOy) are thought to be precursors of OZONE FORMATION (not destruction).
    So, is the EPA claiming that NO/NO2 simultaneously creates ozone near ground level while also destroying it higher up because the mechanisms are somehow different at different levels of the atmosphere?
    Google “Ozone Precursors” to see the proposed mechanisms for ozone formation involving organic chemicals and oxides of nitrogen… seems to perfectly contradict the destructive pathways shown in your post….

  140. PeterB in Indainapolis (10:13:06) :
    Keep in mind that I am not proposing, defending, or critiquing the information coming from those sources. My post was “reporting” the sources which are being used by the named scientists to hypothesize the effect of a local hypernova on the proposed mass extinction events upon the Earth. Since the proposed gamma ray conversion of nitrogen compounds in the upper atmosphere are alleged to produce NO(x) catalysts that are destructive with respect to the Ozone Layer, the mainstream media has been prolific in linking the story to the alleged effects of similar air pollution sources. Since this involves the IPCC, UK government, US government, Greepeace, WWF, and the other usual suspects, the hypernova link to a proposed Snowball Earth has brought us full circle back to the IPCC et al. This appears to open multiple issues needing further investigation. The role of the nitrogen compounds can be expected to become yet more featured articles on WUWT (smile).
    Personally, I haven’t gotten past the first step to address the cationics. I still want to see the proposed mechanisms for the gamma rays altering the compounds of nitrogen into laughing gas and so forth. Now, I’m not saying they do or don’t. Its only a matter of the publications not going into such details….

  141. PeterB in Indainapolis (10:13:06) :
    Note, you may find it worthwhile to look more closely at the two cited sources. I’ll let you draw your own conclusions, but the biographies and wide assortmnt of articles, news stories, and other information may prove to be very revealing for you. Search on their “surname” and “ozone” to find these sources. There are stories their awards such as the Nobel Prize, and stories about their activities in the environmental movements. For example:
    ESA History
    http://www.esa.int/SPECIALS/Space_Year_2007/SEM8IE9RR1F_0.html
    Paul Josef Crutzen (1933)
    Crutzen was unable to finance a university education and his grades were not good enough for a scholarship.
    http://www.uu.nl/EN/research/halloffame/nobelprizewinners/pauljosefcrutzen/Pages/default.aspx
    Paul J. Crutzen (1933-). “The influence of nitrogen oxides on the atmospheric ozone content”, Quarterly Journal of the Royal Meteorological Society 96, 320-325 (1970). (Manuscript received 5 November 1969, communicated by Dr. C. D. Walshaw)
    http://web.lemoyne.edu/~giunta/crutzen.html
    Martin, Brian. The Bias of Science. Canberra: Society for Social Responsibility in Science (ACT), 1979. Part II: Pushing of arguments in the work of Johnston and of Goldsmith et al. [pp. 25-36]; Chapter 1: Technical assumptions; Chapter 2: Selective use of evidence; Chapter 3: Selective use of results; Chapter 4: Method of referring to alternative arguments.
    https://www.uow.edu.au/~bmartin/pubs/79bias/part2.html

  142. D. Patterson (11:30:28)
    Presumably a big / close enough super / hypernova would not necessarily need an intermediary like NO to cause extinctions – direct ionising effects on organisms would occur at high enough levels. The initial gammas might be very low LET due to high energy but by spallation would cause a cascade of lower energy more ionising particles and photons. But I guess the geologic record would show this clearly if such a high gamma (and derived) dose had been delivered.

  143. D. Patterson (11:30:28)
    Sorry – not spallation (wrong process) just Compton scattering and other interactions causing a cascade of secondary (delta) particles.

  144. Moon craters.
    I was remembering the first maps of the far side, which did not show as much detail as is availible today.
    My error.

  145. phlogiston (17:20:35) :
    D. Patterson (11:30:28)
    Sorry – not spallation (wrong process) just Compton scattering and other interactions causing a cascade of secondary (delta) particles.

    Some of the discussion of the suspected GRB role in the Ordovician and other ice age and extinction events sees a more complex explanation that includes cosmic rays bringing about spallation in addition to the various effects of the gamma rays.

    Most of the gamma rays are degraded by interaction with the atmosphere, but the prompt UV flux at the surface (Smith et al., 2003) could still exceed existing levels by more than one order of magnitude. Most of the burst energy incident upon the atmosphere goes into ionizing it. If ultra-high energy cosmic rays (mostly protons) accompanied the GRB, they could irradiate the surface with muons, secondaries produced by interaction with the atmosphere, while producing radionuclides by spallation. However, it is unlikely that many beamed cosmic rays would be energetic enough (>1018 eV) to travel nearly undeflected by galactic magnetic fields and arrive at Earth coincident with the photon burst. Most cosmic rays will scatter and add a contribution comparable to the background from supernovae. A strong burst of cosmic rays at the Earth would be expected only for isotropic GRB emission with a very hard spectrum. Thus, the instantaneous biotic effects of GRB will be moderate and confined to the facing side of the Earth.
    [….]
    Melott et al. Did a gamma-ray burst initiate the late Ordovician mass extinction?
    http://bear.phsx.ku.edu/~medvedev/grbio/grbio.pdf

    Discussion of the consequences of a GRB tends to focus mostly upon the production of NO(x) compounds in the Ozone Layer, because the effects of direct irradiation of lifeforms are limited to only the one side of the Earth facing the GRB and only the the exposed terrestrial and pelagic environments. By contrast, any global cooling caused by GRB ionizing and dissociating the nitrogen and oxygen compounds destructive of the Ozone are global in their effect upon lifeforms and must affect the whole Earth.
    With respect to evaluations of the Snowball Earth scenarios of the Archean and Proterozoic Eons, the effects of a GRB on lifeforms are minimal because macroscopic lifeforms had not yet colonized the terrestrial landscapes. Since the effects of direct radiation are attenuated by the atmosphere and the upper few meters of the hydrosphere’s marine environment in the hemisphere facing the GRB, the other global effects become more important to the consideration of global cooling events. To the extent a GRB could have any contributing effect upon triggering global cooling and an ice age, any effects such as proposed NO(x) destruction of the Ozone Layer and reduced insolation tend to be the focus of so many investigations.
    Now its a question of whether or not and to what degree do the works of the cited authors of the NO(x) hypotheses withstand scientific scrutiny versus environmental advocacy in the guise of science?

  146. In reply to D. Patterson (06:39:37) :
    I think that you are missing the point. I claimed that your statement, “The nitrous oxide would soon rain out as acid rain, but the damage caused by UV-B from the Sun would already extensively damage DNA and temperatures would plummet,” did not make sense because you are not accounting for ozone formation. Ozone is generated by ultraviolet radiation. As high energy ultraviolet photons react with a oxygen molecules in the atmosphere they cause each molecule to break into two oxygen atoms. Those atoms react with other oxygen molecules to make ozone.
    What this means is that the nitrous oxides would not have the same impact that you are claiming because ozone formation is self regulating. This is why we see a reduction in ozone concentrations during the winter; while ozone destruction continues, there is less ultraviolet radiation to create ozone. That reverses in the summer when the greater intensity creates more ozone.

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