Talk:Snowball Earth

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edit·history·watch·refresh Stock post message.svg To-do list for Snowball Earth:

This 'To Do' list contains suggestions that should be addressed before nominating this article for Good Article status.


Here are some tasks awaiting attention:
  • Cleanup: List of references at end of article should be linked to from the main text. A 'recommended reading' section may be helpful to include comprehensive references.
  • Copyedit:  :The article varies in tone and style from over-casual to very scientific. Grammar is questionable in places. Aim for consistency!
    There's a lot of editing required to successfully meet clause 1 - 'well written'.
    Check that the article is compliant with the Wikipedia style guidelines.
  • NPOV: *The article should go further to address both points of view.
  • Verify: All statements should be sourced - try Google Scholar. If it's not possible to source them, consider removal.
Wikipedia CD Selection
WikiProject icon Snowball Earth is included in the Wikipedia CD Selection, see Snowball Earth at Schools Wikipedia. Please maintain high quality standards; if you are an established editor your last version in the article history may be used so please don't leave the article with unresolved issues, and make an extra effort to include free images, because non-free images cannot be used on the DVDs.
 
Archives: 1

Do not treat it as a FACT[edit]

Some have claimed that his article is POV-ridden, but I personally find it to go beyond that. The intro and first two chapters is not trying to convince the reader about the validity of this hypothesis, it takes it for granted, and present it more or less as a fact. To the extent of my knowledge is there no consensus regarding this hypothesis, and the article ought to reflect that. --Sparviere (talk) 23:15, 11 September 2010 (UTC)

The article begins by identifying this as a hypothesis. As I read it now there is no implication that this hypothesis is widely accepted. The Introduction should describe the hypothesis and characterize its status within the scientific community or within the history of scientific knowledge. As it stands the Introduction is already a mess due to the overeagerness of critical editors to blurt out detailed counterpoints and objections before we've even had a discussion of the hypothesis, its history, and the evidence for it, if any. This hyper-critical approach has already left us with a schizophrenic Introduction. Let's exercise some patience and let the article unfold as it would in a classroom or traditional reference book article. 75.73.91.254 (talk) 20:34, 27 December 2010 (UTC)

"The geological community generally accepts this hypothesis" Got a reference for this statement? A quick google scholar search of "snowball earth diachronous" will show several hundred counter arguments. Cwmagee (talk) 11:26, 19 October 2010 (UTC)

True Polar Wander[edit]

cleaned up that little section, it seemed confused before --Ezkerraldean (talk) 15:56, 13 May 2010 (UTC)

Need Tony Robinson mentioned[edit]

Some portion of the population is getting this (dubious?) theory presented as fact by the highly respected television historian/archaeologist Tony Robinson. Now, the likelihood is that Robinson is wrong in this case but mention of it is definitely needed by a reader like me, who'd only ever heard of this theory because of last month's television show (which, in these days of digital and BBCi more than ever) will probably be widely and even repeatedly seen by everyone interested in science and pre-history (perhaps all over the world?). MalcolmMcDonald (talk) 13:39, 1 January 2009 (UTC)

I don't think wiki is here are a news-source; or to debunk TV trivia William M. Connolley (talk) 20:42, 1 January 2009 (UTC)
I've discovered there there are serious problems at the Global Warming article - since there is (rather to my surprise) serious opposition to the standard model. The opposition barely gets any mention - when it does get a mention and a link number 10, one is instead taken to a National Post article that says global warming cannot/should not be fought!
Meanwhile, at this article, we get only the opposition case with no mention of the (unscientific but clearly significant) fact that, in some parts of popular culture, it is "Snowball Earth" that is treated as the orthodox point of view!
I don't know the truth of either of these theories, but it looks as if one is being substantially over-sold and the other substantially under-sold. MalcolmMcDonald (talk) 16:38, 4 January 2009 (UTC)
I don't quite understand you. It seems to me that both sides of the issue are presented here - the hypothesis, the evidence for it and the opposition to it. Whats the problem? William M. Connolley (talk) 17:58, 4 January 2009 (UTC)
Who do you expect people to believe, William Connolily or world-famous archaeologist and (and important Blackadder side-kick) Tony Robinson? Leave out Robinson and it's obvious you've either not heard of, or choose to ignore, all the experts. MalcolmMcDonald (talk) 18:16, 18 January 2009 (UTC)
I don't think you can be seriously claiming that Tony Robinson (a much-loved actor who has presented a famous archeology dig show and appeared as a presenter in a few documentaries) is an archeologist. He really isn't an expert on the subject, he's just a very good TV presenter with an amateur interest. That isn't to deny that he's brilliant at his job. But he isn't an archeologist. --TS 18:52, 23 January 2009 (UTC)

Another episode of "Snowball Earth" on tonight, and Robinson is telling us that this is for sure how all multi-celled life came about. 25 million years of Snowball Earth broken came to an end due to large volcanoes burning through the ice and giving off lots of CO2. This encouraged the cyano-bacteria a clear field to turn it the CO2 into oxygen, triggering the development of multi-cell organisms. This rescued the world from being dominated by slime. Shouldn't someone tell him that this theory really isn't accepted? Or should the article mention him and his series rather than trying to pretend it's all black-magic? MalcolmMcDonald (talk) 21:13, 14 February 2009 (UTC)

Even if he is an archaeologist, he certainly isn't a palaeoclimatologist, geochemist or geologist. This article is based mainly on reliable sources published in peer-reviewed journals, and presents a point of view that may be slightly biased, but does at least acknowledge both points of view. The theory has lost a lot of weight over the past few years, which could be why Robinson's researchers haven't picked up on the criticism - one can hardly expect BBC researchers to be trawling through the peer-reviewed literature. If you do suspect a point of view problem, the best way to address this is to find some sources supporting the neglected point of view. One such source, which I actually came here to point out, can be found at [1] / doi:10.1016/j.palaeo.2009.03.013. Martin (Smith609 – Talk) 16:57, 30 March 2009 (UTC)
Thank you for the source - I read the last statement "In general, the results support ... the pan-glacial character of Sturtian (715 Ma) and Marinoan (635 Ma) ice ages" of the abstract to mean that glaciers ceased to function. Presumably, the northern glaciers came face to face with the southern glaciers in true and complete "Snowball Earth". Other parts suggest that glacial deposits can be found at <30deg, which makes for full freezing.
However, I'm less interested in "the truth" than in presenting the encyclopedic view-point. Which, as far as I can tell, is that informed opinion is split (either evenly or at least with reputable sources still defending both views) while the popular view is in favor. It may be there's an end-run being attempted around the scientific community by collaborating with the media to claim a "win" for their POV, but that only makes it even more important that the article is not written in it's current one-sided condition. The BBC won't have done an done an in-depth review of the literature, but it will have spoken to published "experts" and it gave those experts a clear field, effectively declaring "Snowball Earth" to be orthodoxy. By ignoring this angle, Wikipedia makes itself look as if it's out of touch. I think we should put back: "Popular endorsement" Tony Robinson's Channel 4 (UK television) series "Catastrophe", broadcast 1st Dec 2008, treated "Snowball Earth" as if it was established scientific orthodoxy.[1] = 1. ^ Catastrophe: Planet Snowball Channel 4. 1st Dec 2008. MalcolmMcDonald (talk) 14:14, 31 March 2009 (UTC)
As far as I know, the theory is generally-well accepted that even if the oceans didn't entirely freeze over, sea ice reached to near the equators. Martin says that there's some recent controversy, about which I don't know; evidence I've seen/read seems to be in favor. I think, though, that Wikipedia shouldn't respond to TV shows, etc.; I think it should be a resource that shows the scientific standpoint irregardless of the popular view, to be a resource for those who want to know more. Awickert (talk) 22:39, 1 April 2009 (UTC)
Reading the article, one would think that "Snowball Earth" was a fairly outlandish theory rather like the aquatic ape, probably not written off completely but a real out-lier that almost nobody accepts. Whereas you, and the reference above, make it seem as if it's entirely possible that SE is true. And Robinson is telling the great unwashed that it's true. The whole article needs to be better balanced, either treating SE as most probably genuine (promote to first option), or at least warning the reader that rather a lot of people have been assured that it's genuine (demote to 2nd choice). MalcolmMcDonald (talk) 18:19, 2 April 2009 (UTC)
Irrespective of the merits of SE, sourcing it to TR is a bad idea William M. Connolley (talk) 20:19, 2 April 2009 (UTC)
That's funny - I thought that the article did generally lean towards it being genuine. Although I always looked at the article, not at the lede, and the lede makes it seem less so. As far as I know, it's a major hypothesis, with a lot of supporting evidence. I'll nudge Martin at his talk page to see why he says it's lost support recently. Awickert (talk) 02:43, 3 April 2009 (UTC)
Actually, looking at the "Scientific Dispute" section, I think you're right - the language is strong, like "thus disproving...". Awickert (talk) 02:49, 3 April 2009 (UTC)

"Dispute" definitely needs work - sourcing "its mathematically impossible to freeze the oceans" to [2] is unacceptable (BTW, being no longer a sci I don't ahve access to the paper - do you feel like mailing it to me?) William M. Connolley (talk) 09:00, 3 April 2009 (UTC)

Yeah - that was another one that really popped out at me - especially since this isn't about the math, but about the physics. Article on the way. Awickert (talk) 09:08, 3 April 2009 (UTC)
The first paragraph of "controversy" had way too much weasel-worded mis-cited garbage. I fixed as much as I could; I'll get to the rest sooner or later but (believe it or not) cleaning up the trash on Wiki isn't my favorite passtime. Awickert (talk) 09:47, 3 April 2009 (UTC)
Thanks. I've expanded the GCM bit a little, based on that paper William M. Connolley (talk) 21:21, 4 April 2009 (UTC)
Thanks for making it more informative. I'll hopefully get to the other parts sometime soon, probably after reading more. Awickert (talk) 21:35, 4 April 2009 (UTC)

Scientific evidence relating to extent of Snowball Earth[edit]

I've been asked to comment on this discussion. It's now a while since I studied Snowball, and there's not been too much new literature out recently to keep me fresh, so I may be a little out of touch. However, A brief summary of the current facts would be as follows.

I'll re-iterate the point that the content of a BBC show should have no bearing on the content of this article. This article may have PoV problems, but reliable sources are out there for the finding, and the collective time and knowledge of WP editors allows us to come to a more accurate conclusion than a BBC researcher trying to spin an interesting story, probably relying more on text-books than on up-to-the-minute primary literature. The BBC show did not cite its sources, I assume, so this article should rely only on verifiable sources.

Without further ado, here's my brief recollection of the argument:

  • The reliability of the palaeomagnetic data which suggested that ice reached to the equator at sea-level has been called into question. Only one datum point is placed in the tropics with any confidence. Reference: A.G. Smith 2008 (or 2009?)
    • A rebuttal to this claim came out last week: [3] / doi:10.1016/j.palaeo.2009.03.013
    • Therefore this article should probably convey a sense of uncertainty around palaeomagnetic reconstructions
  • The glacial origin of some near-equator sediments has also been called into question - other processes may have formed diamictites. See, for example, the review in the further reading section.
  • Evidence of an active hydrological cycle is present throughout the Snowball Period - the entire Earth cannot have been solid, or such sediments could not have been produced
    • I'm not aware of a current interpretation of these data that fits them with a hard-snowball hypothesis.
  • The amount of CO2 needed to break out of a complete global glaciation would leave geochemical signals which do not match those recorded
  • Models fail to simulate global glaciation

Most of these points are in fact brought up and referenced in the article. While none of them disagree with widespread glaciation, the global extent looks very questionable.

The feeling in the popular press may be the 'sexy story' that the whole Earth was frozen, but recent scientific evidence makes that look more and more unlikely - I might go so far as to say impossible. I personally find the 'Sedimentary challenge to Snowball Earth' the most compelling argument against it. However, it is important that WP provides an accurate portrayal of both points of view.

I'm not sure what the best way of resolving the involved issues would be. As I see it there are two ways of structuring the article - either each piece of evidence or suggested mechanism should be presented in turn, with both the 'pro-snowball' and 'anti-snowball' interpretations presented; or the pro-snowball case should be stated; followed by the anti-snowball case. [It's not quite this clean-cut; there are 'middle grounders' who propose a 'slushball Earth'.] My preference, which I had originally aimed for in the 'Evidence' section at least, would be to present each point of the article with both points of view. I think the best thing to do would be, if enough interested editors are willing, to settle on one of these viewpoints, and work on getting the article properly referenced and unbiased.

I hope that these comments are vaguely helpful! Martin (Smith609 – Talk) 14:02, 3 April 2009 (UTC)

Thanks a ton - they are very helpful! From what I've been reading recently as well, it seems like many think it to be a slushball, with some ice-free area near the equator, via the middle ground, but I haven't really even breached the first layer of literature on this. Awickert (talk) 17:00, 3 April 2009 (UTC)
Thanks too, Martin. Your text quite nicely sums up the caveats regarding the theory. The scientific debate over this theory is still underway. There is quite a lot of geological evidence involved, and a lot of guessing, so it's a complicated issue. Furthermore it is a sexy theory with a lot of public reception.
It would a useful thing to describe some of the evidence to some depth without interpretation first, right after the lede and the history of the theory: what areas are involved, what rocks and what geology do we find? There are some good papers about the outcrops, their stratigraphy and composition.
Then interpretation, first pro, because this article describes the theory, then discussion and alternative interpretations. jm2c --Jo (talk) 21:40, 3 April 2009 (UTC)
I agree - this sounds like a good way to construct the article. Unfortunately, I know very little about it, and just trying to make the first paragraph of the opposition section match the references given took around an hour (mis-citations take forever to fix, because I have to read so much). If there's anyone who knows a lot more of the content than I do who wants to lead the charge, I'd be happy to back them up. Awickert (talk) 22:49, 3 April 2009 (UTC)
Martin - thankyou for that, I agree we should settle on one point of view (presumably, in this case, that SE is not really accepted). Is there anything to tell us how to write articles in these circumstances? Later - judging by what else I'm seeing, the default position is to write up a theory as if it's true and then undermine it in subsequent sections. In other words, treat "Snowball Earth" as true in the lead. ie not talk about "a hypothesis" nor speak of "a claim". MalcolmMcDonald (talk) 14:27, 5 April 2009 (UTC)
I prefer Jo's idea: present the evidence, then present theories. It avoids the whole right/wrong/debate issue, which is especially important because it seems that snowball Earth is partially right, which might get undermined with refutations - just my 2 cents; I don't see myself being very useful on the article with my present level of knowledge. Awickert (talk) 20:00, 11 April 2009 (UTC)
The current state of the article paints SE as an odd-ball theory that might be true but isn't really taken seriously by people in the know. I was startled when I googled it in, having just seen the box tell me (fairly authoritatively) that Snowball Earth led directly to multi-cellular life on earth. Meanwhile, I think I just saw something completely different (and likely shonky) described in an article which started as if the thing was true before undermining it (presently I'll probably remember what I was looking at). MalcolmMcDonald (talk) 20:27, 11 April 2009 (UTC)

Balance is missing[edit]

I'm finding more indications of imbalance in this article, since it tries to persuade us that the SNOWBALL EARTH theory is generally unlikely, when the consensus/evidence may not agree (and I suspect this is a bad way to write an article anyway).
For instance, there is an (almost totally useless!) picture of a wind-blown ice-sheet with the caption "Global ice sheets may have delayed or prevented the establishment of multicellular life." But the article says the opposite - all references to "multi-cellular" seem to tell me the same thing that presenter Tony Robinson did, SE was a vital factor triggering complex organisms as we know them! I hesitate to edit this article, because it is much more nuanced and dense than I can yet fully understand, but I'm sure that picture and caption should come out. MalcolmMcDonald (talk) 09:32, 18 April 2009 (UTC)

Then yank 'em. I don't think there is currently anyone with the expertise and motivation to really do a good job on the article, so since you seem interested, be bold. Awickert (talk) 16:43, 18 April 2009 (UTC)
If this article was written as I think it should be, putting a positive gloss on the theory and then providing all the good reasons for not believing it, then people like me could come in and make incremental improvements. As it stands, it makes progress along the lines intended in WP:CCC virtually impossible. MalcolmMcDonald (talk) 16:59, 18 April 2009 (UTC)
Well, then, maybe it needs more fundamental help from interested folks like you. Awickert (talk) 17:35, 18 April 2009 (UTC)

Articles[edit]

Glaciation on the Precambrian–Cambrian boundary[edit]

Higher importance?[edit]

I think that this article should be of more importance! —Preceding unsigned comment added by Bdoom (talkcontribs) 19:43, 8 October 2009 (UTC)


Citations?[edit]

I saw a history channel (or similar channel) and maybe someone could get permission from them to use some of them. —Preceding unsigned comment added by Bdoom (talkcontribs) 19:24, 5 November 2009 (UTC)

flood water[edit]

kailangan po na wag pong magputol ng three forest para po hindi po tayo magkaroon ng pagbaha sa ating kapaligiran kaya po iwasan po nating magputol ng mga puno ayan lang po ang aking palala sa nag puputol ng puno sa gubat natin dapat nating pangalagaan natin to —Preceding unsigned comment added by 112.200.111.129 (talk) 13:53, 15 November 2009 (UTC)

TRANSLATION FROM FILIPINO: Please mind that you do not cut the forest for three po po do not we have flooding in our environment so please please avoid the trees we cut here is my only retrograde to offer a full puputol we should protect our forest we have to. I don't know why this is here, is it that bad to delete nonsensical comments in a discussion page?Larryisgood (talk) 15:29, 13 May 2010 (UTC)

Earlier snowball?[edit]

Hi. I've noticed most of this focuses on controversy about the later Precambrian (Cryogenian period) "Snowball" possibility. But is there anything more that could be said (other than the brief bit already here) about the even earlier Huronian glaciation in the deeper Precambrian around 2.2 billion years ago? Is there any new research on that that would resolve whether or not a "snowball Earth" had occured? mike4ty4 (talk) 00:28, 29 December 2009 (UTC)

If you have a reliable source for the Huronian glaciation then it would deserve a few lines or a "See Also" at the bottom of the article.
As regards this article, you might be rather more interested to see the update I've just made here. Some sources clearly believe that "Snowball Earth" is "proved", a totally different conclusion from the one you'd get reading the article here! MalcolmMcDonald (talk) 12:48, 8 January 2010 (UTC)

Tag this as POV[edit]

I propose this article be tagged as POV because, perhaps accidentally, or perhaps as a side result of the cabal controlling Global Warming and all articles on GW/AGW, it fails to deliver value to the reader.

A supporter of the article in it's current condition has written a thoughtful defense of the current state of the article on my TalkPage and he may well be right - Brittanica and New Scientist indeed treat this theory as likely false and up against unresolved scientific problems respectively.

However, public awareness rates Channel 4 and, in particular, the actor/presenter Tony Robinson, far higher than the august sources mentioned above - and our spokesman insists that even a mention of the documentary available on-line will never happen. I've since found a 2001 BBC documentary that appears to support SE as well.

I'm not prepared to argue with contentions made that seem to comply with no policy whatsoever, but I'd like this article to be tagged POV until someone else fights for the balance it deserves. MalcolmMcDonald (talk) 16:05, 10 January 2010 (UTC)

You're seriously sayng the we should defer to Tony Robinson on our coverage of science? I'm watching the BBC Horizon documentary now and they definitely represent it as fringe. --TS 16:18, 10 January 2010 (UTC)
You have got to be kidding... We prefer Channel 4 and "public awareness" over science ... On a scientific subject? --Kim D. Petersen (talk) 04:31, 11 January 2010 (UTC)
Malcolm: edit / improve the article if you like. Snowball Earth is generally (but certainly far from universally) accepted in the scientific community. I don't see why we shouldn't add to "external links" links to online-available documentaries. However, documentaries are often spun, so best to use them as an "external link" rather than "the truth", especially since the documentary you mention seems to pick one side of the scientific argument (which is the side I happen to agree with, but not everyone does). Also to Malcolm: I hate talk:Global Warming and related battlegrounds; please strike parts of your post that are designed to accuse and inflame instead of produce, or I will delete this thread per WP:TALK and the fact that this is a rehash of what we've discussed earlier. Awickert (talk) 05:26, 11 January 2010 (UTC)
I've made a small further change (rewording where it speaks of Mawson's "wrong assumption"). I see a tag "not referenced" at section "Mechanisms" here - can someone more expert than me put in the necessary links? Or tell me where there is a good discussion? MalcolmMcDonald (talk) 08:41, 14 January 2010 (UTC)

Title[edit]

Awickert, is there a reason why this article is not named Snowball Earth hypothesis? The term "snowball Earth" can refer to both the glacial period and the supporting hypothesis. Since this article focuses on the hypothesis, shouldn't we change the name? Viriditas (talk) 10:59, 11 January 2010 (UTC)
In the geological community, this topic is generally known as "snowball Earth" (I do see "snowball Earth hypothesis", but much more rarely), so I think that Wikipedia should use the same terminology as the general professional usage. Awickert (talk) 15:25, 11 January 2010 (UTC)
I've looked at the specialist and generalist literature, and whenever "snowball Earth" is used, depending on the context, it is used as a nickname to refer to the hypothesis or the glacial period. Encyclopædia Britannica, the Encyclopedia of Paleoclimatology and Ancient Environments, the journal Science, New Scientist, Scientific American, The Washington Post, and many other sources all refer to this topic as the "Snowball Earth hypothesis". I'm not clear why Wikipedia does not. Viriditas (talk) 22:47, 11 January 2010 (UTC)
As I argued in the conversation we just had, I believe the argument that everyone uses or prefers a longer name is simply not correct. Dragons flight (talk) 02:19, 12 January 2010 (UTC)
And, as I've demonstrated in my draft proposed move (not finished) your "argument" is specious and violates just about every policy and guideline concerning article titles, including Wikipedia:Naming conventions, which stipulate that "article names should be recognizable to readers, unambiguous, and consistent with usage in reliable English-language sources" ("Snowball Earth" is a nickname for both a glacial period and the hypothesis supporting it, and the full term, "Snowball Earth hypothesis", appears predominantly in secondary sources). Your argument in favor of specialist, primary research also violates WP:PSTS (We do not rely on primary research to decide on article titles, but on secondary sources about the topic). It is also important to note that the top, current tertiary sources on the subject, the generalist Encyclopædia Britannica and the specialist Encyclopedia of Paleoclimatology and Ancient Environments, both use "Snowball Earth hypothesis" as the title of their entries. Whenever professional reference works written by experts come into conflict with Wikipedia, we should take a step back and figure out why. Viriditas (talk) 04:27, 12 January 2010 (UTC)
I'm not an expert in the field, neither am I a reliable source, but I have spoken with many of those who research it, and never have they added the word "hypothesis".
To be more rigorous I performed a GeoRef search:
  • "Snowball Earth" NOT "Snowball Earth Hypothesis", in title: 225 publications, 124 of which are peer-reviewed journals
  • "Snowball Earth Hypothesis", in title: 14 publications, 6 of which are peer-reviewed journals.
It is clear that there is no conflict between usage in the scientific literature and usage on Wikipedia. Awickert (talk) 05:53, 12 January 2010 (UTC)
You're making a similar argument that was previously made by Dragons flight, and I don't get it. We don't gauge article titles by looking at headlines or journal article titles, and I don't understand why this argument keeps being brought up. We're interested in how the subject is described in secondary sources, most of which call it the "Snowball Earth hypothesis". "Snowball Earth" is an ambiguous nickname that can mean several different things, as I have already pointed out above. Viriditas (talk) 10:22, 12 January 2010 (UTC)
Scientific journal articles have trouble falling into the standard categorization scheme used by historians; I would actually consider them closest to secondary sources (with primary sources being the scientists' data tables and notebooks).
That aside, what you are insisting is that we should ignore what the scientists call it, which would be absurd IMO. Wikipedia repeatedly states that peer-reviewed journal articles are the best possible source. This includes WP:PSTS, which states, "In general the most reliable sources are peer-reviewed journals and books published in university presses...", in opposition to your above claim that, "[the] argument in favor of specialist, primary research also violates WP:PSTS". You are incorrect that "snowball Earth" is a nickname for a glacial period; it is a term for a hypothesized period of global or near-global glaciation, and as such is unambiguous. I don't have anything else new or useful to say here, so I'll stop. If you like, please take this to the appropriate noticeboard, because so long as you (a) devalue scientific sources and (b) don't get facts straight, I'm going to be standing in your way. Sorry for being short, much to do and little time, so best to be clear about my position. Awickert (talk) 15:39, 12 January 2010 (UTC)
The scientists call it "Snowball Earth hypothesis", as seen in a press release written by the Geological Society of America for Biotech Week on March 4, 2009, covering upcoming articles in the journal Geology and GSA Today. You've made an error in judgment and you've greatly twisted and distorted what I've said and written into a straw man you can knock down without even bothering to look at the actual facts. I have not "devalued" scientific sources of any kind nor have I misquoted PSTS. Primary sources in the natural sciences are defined as "a report of original findings or ideas [that] often appear in the form of research articles with sections on methods and results." See also: Wikipedia:Evaluating_sources#Examples_by_field. These primary sources use the nickname "Snowball Earth" to refer to not one topic but three, both the glacial period, the event, and the hypothesis. I am not "incorrect" about the usage as a nickname, as this claim is widely supported in the literature. For only one example see Sohl & Chandler:

The Cryogenian interval (850-635 Ma) is marked by glacial deposition on nearly every modern landmass except Antarctica (Hambrey & Harland 1981, 1985) during two episodes commonly referred to as the Sturtian and Marinoan (or Varanger) glaciations. What makes these two glaciations unusual is their severity compared with the Pleistocene glaciation, leading to the nickname 'snowball Earth' glaciations.[4]

So, you are incorrect that "snowball Earth" is not a nickname for a glacial period, and it is used ambiguously in the literature to refer to glaciation periods,[5][6] events,[7][8] and the hypothesis[9][10] that supports it. Those links represent hundreds of selected examples of ambiguous useage. You are also incorrect in your reading of PSTS. We do not rely on primary research to decide on article titles, but on secondary sources about the topic. As PSTS makes clear:

Wikipedia articles should be based on reliable, published secondary sources and, to a lesser extent, on tertiary sources. Secondary or tertiary sources are needed to establish the topic's notability and to avoid novel interpretations of primary sources, though primary sources are permitted if used carefully. All interpretive claims, analyses, or synthetic claims about primary sources must be referenced to a secondary source, rather than original analysis of the primary-source material by Wikipedia editors.

Dragons flight's entire argument in support of keeping the current name is based on his interpretation of primary sources, rather than the use of the term "Snowball Earth hypothesis" in the secondary literature, which is supported by PSTS and the naming convention policy. It is curious how you could reasonably claim that I am "devaluing" scientific sources when I have cited this sample of secondary scientific sources in favor of "Snowball Earth hypothesis", as well as the entry by Grant M. Young of the Department of Earth Sciences, University of Western Ontario, in the Encyclopedia of Paleoclimatology and Ancient Environments (2009). We don't use ambiguous nicknames as article titles, and when two authoritative encyclopedia entries written by experts use "Snowball Earth hypothesis" and when the majority of secondary sources on the subject use "Snowball Earth hypothesis", that is enough evidence to support a name change. The arguments put forward for keeping this article at "Snowball Earth" violate existing naming conventions and PSTS best practices. Viriditas (talk) 04:15, 13 January 2010 (UTC)
  1. I took a collection of every article written, and averaged in order to get better data. What I see shows that "hypothesis" is used, but I think that it's best to look at as many instances as possible instead of picking just a few, and when I do that, academic sources come down hard on the "no 'hypothesis'" side.
  2. You establish that you're happy to continue making personal attacks. These reflect poorly on yourself and make me disinclined to cooperate with you. I do acknowledge that I wasn't the kindest, but this is because I didn't appreciate you're initial unprovoked aggression.
  3. You are correct as to what WP thinks of academic sources. However, I will stand firm that it matters what these sources say and not what 2ndary sources say; let's take this up on the RS noticeboard if it needs to be cleared up.
  4. Your example actually shows that it is specifically used for a global glaciation; it's a matter of familiarity with the literature, as are your examples. Period and event are used interchangeably by geologists when they aren't sure of chronology, and the hypothesis is inextricably tied to whether or not this period exists, so I contest that this is one topic.
  5. I claim that you devalue scholarly sources because you use popular articles instead of the scientific literature. In all of my experience on WP until now, scientific literature trumps everything. What you call "2ndary scientific sources" are IMO (and in others' opinions as well) much less reliable in general than scientific papers. What this also does is inflate what the science writers say and deflate what the researchers say. If this is the core of the issue, this is more generalizable and is an actionable item that we can take care of in a more public venue. Awickert (talk) 06:40, 13 January 2010 (UTC)
OK, brought it up at WP:RSN, here, Awickert (talk) 07:02, 13 January 2010 (UTC)

Tagging this as POV due to Tony Robinson, or using TR as a source for the article, is absurd. MMD needs to get a clue about what science is, or stop trying to influence science articles. "I saw it on telly" is always the wrong answer for a science article.

Keep the current name. We're having too many profitless arguments about renaming William M. Connolley (talk) 08:19, 13 January 2010 (UTC)

I would like to point out that {{Snowball Earth/Infobox}} does not display on my end (Firefox). Does anyone have trouble seeing this diagram? Viriditas (talk) 08:39, 13 January 2010 (UTC)
Shows up on my browser (Firefox 3.5.7); is it the image, text, or whole thing that doesn't work on yours? Awickert (talk) 16:17, 13 January 2010 (UTC)

Question?[edit]

I watched this BBC program on the Snowball Earth hypothesis. Forgive my naiveity but I was a bit puzzled though by the exit story that absolutely no precipitation meant CO2 build up to 10% over 10 million years. I thought even well below zero ice subliminated in strong sunlight (eg on the equator)? Surely a snowball would have winds, and therefore cloud and precipitation from the subliimination? --BozMo talk 10:43, 12 January 2010 (UTC)

Evap/Subl is stronly temperature dependent, approximately exponential if I recall right. And contrary to what everyone assumes, subl from ice close to zero is pretty well the same as evap from water at zero (yes it is different, but not by as much as a factor of 2 even). So you are correect: a snowball earth would have non-zero ppn. Maybe weathering to draw down CO2 requires liquid water? Awickert would know I think William M. Connolley (talk) 11:43, 12 January 2010 (UTC)
WMC has it correctly in weathering: there would be volcanic outgassing of greenhouse gases, but the vastly slowed hydrologic cycle (and the fact that everything would be covered in ice and chillier than a walrus's backside) would vastly reduce silicate weathering, which is the major governor of CO2 concentrations over geologic time-scales. I bet that this is because the chemical processes to draw down CO2 are temp-dependent, though I am a better physicist than chemist :-). (Ah, yes, silicate weatheirng does decrease with temp, though I can't find a nice temperature-dependence graph on a lazy google or google scholar search.) And BozMo, I believe that you are also correct about the precip: zero precip is a silly proposition because (as WMC points out and I regularly observe) sublimation is very important, and with no precip to refuel the ice sheet mass balance, they'd just sublime away. Awickert (talk) 15:52, 12 January 2010 (UTC)
It's a two step process:
  1. 2 CO2 + H2O + CaSiO3 -> Ca+2 + 2 HCO3- + SiO2
  2. Ca+2 + 2 HCO3- -> CaCO3 + CO2 + H2O
The first step explicitly requires liquid water and essentially operates as carbonic acid dissolving rock to form the aqueous byproducts plus SiO2 (sand). The second step happens in solution, but is usually catalyzed by biology. CaCO3 is a solid that precipitates out of the solution and goes away (unless the acidity it too high). Dragons flight (talk) 16:15, 12 January 2010 (UTC)

Science article[edit]

http://www.sciencemag.org/cgi/content/full/327/5970/1186 William M. Connolley (talk) 12:46, 26 March 2010 (UTC)

That article ("Snowball Earth Has Melted Back To a Profound Wintry Mix", Science, 5 March 2010) is a good review of the topic; you all might take a look at it. - J. Johnson (JJ) (talk) 22:48, 29 July 2011 (UTC)

Snowball Earth graphical timeline[edit]

Snowball Period
-1000 —
-950 —
-900 —
-850 —
-800 —
-750 —
-700 —
-650 —
-600 —
-550 —
Sturtian
Marinoan
Gaskiers
Kaigas
(millions of years)
Neoproterozoic era
Snowball Earth
A recent estimate of the timing and duration of Proterozoic glacial periods. Note that great uncertainty surrounds the dating of pre-Gaskiers glaciations. The status of the Kaigas is not clear; its dating is very insecure and many workers do not recognise it as a glaciation. From Smith 2009.[1]

Are there any objections with replacing the existing timeline with one using {{graphical timeline}}? I believe this is more readable, and allows for automatic colouring and placement of periods in the timeline. Also, from the discussion above, it appears there are some problems with the rendering of the existing timeline, which this could fix. Thanks! Plastikspork ―Œ(talk) 14:30, 30 March 2010 (UTC)

It looks great - thanks for putting the work into this! I'd support using this one as a replacement. Awickert (talk) 17:13, 30 March 2010 (UTC)
Supported Babakathy (talk) 20:45, 30 March 2010 (UTC)
Yes, go for it William M. Connolley (talk) 21:54, 30 March 2010 (UTC)
Certainly an improvement. Any chance of extending it to include the Paleoproterozoic era? --Michael C. Price talk 11:00, 31 March 2010 (UTC)
That could be done, but are there specific named events to put within that Era? Plastikspork ―Œ(talk) 15:33, 1 April 2010 (UTC)
If I've understood the links correctly then this snowball phase was triggered by the great oxygenation event. --Michael C. Price talk 19:30, 1 April 2010 (UTC)

The duration of "Marinoan" glaciation[edit]

New age dates from the The "Marinoan" glaciation could be very short. See new age dates from Nantuo Formation in South China
Shihong Zhang, Ganqing Jiang and Yigui Han (2008). "The age of the Nantuo Formation and Nantuo glaciation in South China". Terra Nova 20: 289–294. doi:10.1111/j.1365-3121.2008.00819.x.  Aleksey (Alnagov (talk) 21:09, 7 June 2010 (UTC))

Evidence section appears to contain substantial original research[edit]

A portion of the Evidence section appears to be original research. I believe it is suspicious, and significant, for the following reasons:

  1. The surrounding citations do not appear to contain the numbered decomposition. The particular presentation of this decomposition implies it is decisive and widely agreed upon. There are no citations to support these implications.
  2. It purports to specify what the evidence "must prove" in order for the "theory" to be valid. This presentation is not typical of writing in the scientific literature about hypotheses in geological history. It does not appear to characterize the ongoing scientific work on the hypothesis nor the disposition of the scientific community to that work.
  3. The Evidence and Scientific Dispute sections would be improved if this original research frame were removed from the presentation and they were allowed to stand on their own.
  4. The portion classifies Snowball Earth as a theory rather than a hypothesis, whereas the introductory paragraph of the article classifies Snowball Earth as a hypothesis.

I refer to the following portion:

"Critical to an assessment of the validity of the theory, therefore, is an understanding of the reliability and significance of the evidence that led to the belief that ice ever reached the tropics. This evidence must prove two things:

  1. that a bed contains sedimentary structures that could have been created only by glacial activity;
  2. that the bed lay within the tropics when it was deposited.

During a period of global glaciation, it must also be demonstrated that

3. glaciers were active at different global locations at the same time, and that no other deposits of the same age are in existence.

This last point is very difficult to prove. Before the Ediacaran, the biostratigraphic markers usually used to correlate rocks are absent; therefore there is no way to prove that rocks in different places across the globe were deposited at the same time. The best that can be done is to estimate the age of the rocks using radiometric methods, which are rarely accurate to better than a million years or so.[2]"

I recommend this portion of the evidence section be removed if a citations cannot be provided for each point. —Preceding unsigned comment added by 75.73.91.254 (talk) 20:17, 27 December 2010 (UTC)

Remagnetisation casts doubt on reconstructions of paleomagnetic poles[edit]

9 Jan 2012 More study has recently being done to remagnetisation eg Rowan 2010, Font 2011, which casts doubts on postions of the paleo-magnetic poles, which also implies that low altitude glaciation may not have been on low lattitudes.


AndrePooh (talk) 20:03, 9 January 2012 (UTC)

Current field work[edit]

What is the point of this section? Apart from promoting a special group of researchers. There is lots of field work going on on this topic worldwide. I suggest this to be deleted. — Preceding unsigned comment added by 130.238.141.50 (talk) 16:05, 30 January 2012 (UTC)

Done. Was in 2009 reading tea-leaves anyway. Alfie↑↓© 00:50, 13 June 2012 (UTC)

There are currently glaciers at the equator![edit]

The evidence section start off mention the 'apparent presence of glaciers at tropical latitudes' this should surely be the 'apparent presence of sea level altitude glaciers at tropical latitudes', as I believe there are (still) glaciers on the top of Kilimanjaro, and in the equatorial Andes.1812ahill (talk) 17:41, 13 June 2012 (UTC)

Initiation section[edit]

The Initiating snowball earth section has this sentance: 'During the Cryogenian period, however, the Earth's continents were all at tropical latitudes' when this is clearly contradicted by the maps of continental distributions in the section above it which show a polar centred distribution. Confusing! (1812ahill (talk) 19:37, 13 June 2012 (UTC)

Possible anti-snowball earth explanation Wheller007 (talk) 03:54, 6 February 2013 (UTC)[edit]

What could have happened to compensate for your discovery of certain minerals that could only form under a huge glacier and that glacier was in a landmass that plate tektonics placed it on the equator during the time it had the glacier has 2 possible explanations

1) the tracking of the plates backwards in time was done incorrectly and they weren't at the equator.

2) the landmass was in fact in the position of the current equator but the current equator may not be the same as the old equator (the entire crust of the earth shifted at some point in time and what you thought of was equator was in fact one of the poles)

it's easy to prove, just look at french polynesia and you'll see all the proof you desire. nothing caused those volcanic islands that collapsed to create the coral islands, no plate tektonics can cause them, and if the crust flipped over the island chain will fit in perfectly with the missing bit between hawaii and siberia. speaking of hot spots, you can see proof that the moon was made via a catastrophic strike by looking at the relationship between hawaii's hot spot and yellowstone's.

Wheller007 (talk) 03:54, 6 February 2013 (UTC)

Capitalization[edit]

Move to "Snowball earth"?[edit]

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: The result of the page move request was: Withdrawn by nominator. RockMagnetist (talk) 21:02, 10 April 2013 (UTC)


  • "Earth" is inappropriately capitalized in the title per WP style guidelines. –Prototime (talk · contribs) 20:00, 7 April 2013 (UTC)
  • Snowball Earth is the proper-name of one specific geological period. Anthony Appleyard (talk) 22:40, 7 April 2013 (UTC)
  • Oppose. Proper noun. Apteva (talk) 03:10, 8 April 2013 (UTC)
  • Strong oppose "Earth" is the planet, "earth" is dirt. It is properly capitalized, "earth" is improperly capitalized. -- 65.92.180.137 (talk) 05:24, 8 April 2013 (UTC)
  • Comment – in books it's typically "the snowball Earth hypothesis". So the title is OK, but snowball needs to be downcased in the text per MOS:CAPS. There's no evidence in sources for the "Snowball Earth" proper name hypothesis. Dicklyon (talk) 05:53, 8 April 2013 (UTC)
  • Oppose - That's how it's known - only four out of the first 100 results from GoogleScholar fail to use "E". Mikenorton (talk) 05:59, 8 April 2013 (UTC)
  • In light of these comments, I withdraw the request. –Prototime (talk · contribs) 19:53, 10 April 2013 (UTC)
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

"Snowball Earth" or "snowball Earth"?[edit]

Please discuss here whether this late Precambrian geological period should be named "Snowball Earth" (uppercase S) or "snowball Earth" (lowercase s). Anthony Appleyard (talk) 08:33, 14 April 2013 (UTC)

P.S. Google search shows mostly uppercase 'S' here. Anthony Appleyard (talk) 07:39, 13 April 2013 (UTC)
Even if you ignore the book evidence I linked above and prefer to use random web pages, there's nothing in MOS:CAPS about going with majority usage. This is clearly not a proper name, per evidence in books and in the cited sources, and should not be capitalized per MOS:CAPS. Most scholarly papers do it in a style like ours, too (if you look past the titles). I will put it back to "snowball Earth". Dicklyon (talk) 06:15, 14 April 2013 (UTC)
I agree that the capitalization should comport with scholarly usage, not majority usage. A general Google search does indeed return many more results where the term is stylized as "Snowball Earth", but as Dicklyon points out, a Google Scholar search--which is much more reflective of scholarly usage--returns mostly results where the term as stylized as "snowball Earth." Unless some additional evidence comes to light to suggest that the proper style per scientific usage is otherwise, we should use "snowball Earth" in this article. –Prototime (talk · contribs) 16:41, 14 April 2013 (UTC)

Glacial deposits questioned[edit]

It has been suggested that the glacial deposits found is not really glacial. Can’t professional Geologists tell the difference between a rock layer formed from moraine and one formed from the result of landslides?

2013-12-31 Lena Synnerholm, Märsta, Sweden.

Paleomagnetism[edit]

It has been suggested that the Earth may not have had its dipolar magnetic field back then. I think the interior of the Earth has been essentially the same for the past thousand million years. Anyone who can verify this?

2013-12-31 Lena Synnerholm, Märsta, Sweden.

Slushball Earth world maps[edit]

The world maps lack information on how long ago the positions of the continents it was based on were. I have wondered about this for a long time now.

2013-12-31 Lena Synnerholm, Märsta, Sweden.

Snowball Breakout[edit]

I have noticed that the discussion of mechanisms to end the hypothesized Snowball Earth episodes does not include the idea of asteroid impacts. Even a small asteroid will throw up a large amount of dust that would cover the ice and turn sunlight into heat. Further the flood volcanism instigated on the opposite side of the planet by the impact's shock waves would throw up more dust and large quantities of carbon dioxide. The subsequent global warming event would then end the super-ice age. Over the past eon significant asteroid impacts and their associated flood volcanism have occurred roughly 60 million years apart, frequently enough to keep Earth mostly ice free. I can't believe that I am the only person who has conceive this idea. Surely some geologist somewhere has conceived it and published a paper describing it. All we need is a Wikipedian with expertise in the literature of geology to find that paper and improve this article accordingly. Kanawishi (talk) 15:27, 20 September 2014 (UTC)

You're not the only one, it was proposed a few years ago by Abbot & Pierrehumbert (2010) that volcanic dust might do the trick. They proposed the ice was coated by layers of volcanic dust that decreased albedo and provoked melting; Abbot, D.S. & Pierrehumbert, R.T. 2010. Mudball: Surface dust and snowball Earth deglaciation. J. Geophys. Res, 115, D03104. Also, Gudmundsson et al., (2012) directly measured the effects of volcanic aerosol deposition on the Langjökull ice, yes, volcanic aerosols caused increased rates of melting; Gudmundsson, S., Pálsson, F., Björnsson, H., Magnússon, E., Thorsteinsson, T. & Haraldsson, H.H. 2012. The impact of volcanic aerosols on the energy-and mass balance of Langjökull ice cap, SW-Iceland. In: AGU Fall Meeting Abstracts. 0659. So it seems a plausible idea has been confirmed in the field.--Diamonddavej (talk) 18:28, 6 October 2014 (UTC)
    • ^ Smith, A.G. (2009). "Neoproterozoic timescales and stratigraphy" 326. Geological Society, London, Special Publications. pp. 27–54. doi:10.1144/SP326.2. 
    • ^ Cite error: The named reference Eyles2004 was invoked but never defined (see the help page).