Now "it's volcanoes", according to Anthony Watts!
Anthony Watts is a dim and rather rough gruff bloke who runs a climate conspiracy blog called wattsupwiththat, better known as WUWT or WTFUWWUWT. He claims he accepts the greenhouse effect, but only a little bit, and only as long as he doesn't have to pay taxes. He has a strong aversion to climate science, and falsely accuses climate scientists of fraud, and when they so rightly object he accuses them of "sliming" him.
Anthony's deepest fear is that an asteroid is about to come down from the heavens and smite him, which is rather unlikely. He promotes and encourages a lot of conspiracy theories, ranging from the scientists are committing fraud through to Pope Francis is a KGB sleeper agent, to it's a plot of evil green nazi communist fascist types who want to rule the world to the simple "physics of the past two hundred years is a hoax". He's posted various "theories" for global warming on his blog, when he admits that it is warming, ranging from "it's Russian steampipes" through to "OMG it's insects". Unsurprisingly, his blog has made a small contribution to the advancement of cognitive science.
Today Anthony has decided (archive here, latest here) it must be underwater volcanoes, not CO2, that "were the driver" behind the snowball Earth.
He's posted a press release about a new paper in Nature GeoScience, which looks quite interesting. Anthony's headline and opening words were (my emphasis):
Claim: Explosive underwater volcanoes were a major feature of ‘Snowball Earth’
Anthony Watts / 1 hour ago January 18, 2016
From the UNIVERSITY OF SOUTHAMPTON the “splode” department comes this interesting claim that tries to make CO2 the driver rather than volcanoes themselves. It looks like a big leap of speculation to me.
WTFUWWUWT? Really? You can almost hear a volcanic rumble as his brain cells bounce and bump about. They don't connect with each other too often. If you listen hard, you may hear a low frequency grinding noise - could be the gears grinding.
Now I haven't a clue about what was going on in Anthony's mind. I don't know if Anthony thinks the volcanoes caused Earth to freeze or whether he thinks they caused it to unfreeze. He doesn't say. Perhaps he figures that volcanoes, without a change in CO2, caused the ice to melt. Think beds of hot rocks under the ocean :) If he thinks it must have been all the heat from those hot volcanoes that melted the snowball earth, what does he think caused the Earth to freeze to a snowball in the first place? Reverse volcanoes perhaps? Sucking the warmth out of the air only to belch it back a few million years later?
Unzippered rifts, volcanoes and ocean chemistry
I found the paper and Anthony's press release, with little help from WUWT (which had no links as usual). The team, led by Dr Tom Gernon, are putting forward a case that volcanoes did play a big part in the snowball Earth. However it wasn't the heat from the volcanoes that the authors were discussing. Nor was it any sucking up of heat by volcanoes. Nor was it mainly about the changes in greenhouse gases. In fact it wasn't proposing any major new explanation for the Snowball Earth as a whole. The paper was setting out a hypothesis that would fill some of the knowledge gaps. It was about changes in ocean chemistry, and what caused them, as an explanation for the layers of cap carbonates observed, among other things. Figure 1 from the paper explains quite a bit, and I've written more below. (As always, click the image to enlarge it.)
Disclaimer: I'm not a research geologist or a chemist, so this is just my understanding after reading the new paper and other papers on the subject. (I can boast a prize for geology and a top in physical chem in my undergrad degree a lifetime ago, but I've since forgotten almost everything I learnt :D) I've listed some references in the text and down below, which in turn have a lot more references, if you're interested in following this up. If you see what you think is a mistake or misinterpretation, do let me know. This article covers multiple disciplines - geology, ocean chemistry, biology, climate science and more.
CO2 and snowball Earth
First let's be clear. Atmospheric CO2 changes are the heart of the snowball Earth theory. The notion falls apart completely if you don't allow for the huge changes in greenhouse gases. A massive reduction in greenhouse gases (caused by long term silicate weathering) caused the temperature to drop and the surface to freeze. Each episode ended when greenhouse gases increased enough to cause the ice to melt.
As you may know, there has long been speculation, based on geological research, that the planet was once wholly or largely iced up. Brian Harland wrote an article documenting the history of Snowball Earth and the related Iceball Earth hypotheses dating back to James Thompson in 1871. Australian geologist and Antarctic explorer Douglas Mawson played an important role, speculating (based on geological evidence) that there was planet-wide glaciation during the Neoproterozoic Era. Harland wrote about Mawson describing finds in 1949 and the follow up work, which ultimately led to the modern Snowball Earth hypothesis described by Kirschvink in 1992:
In 1950 Mawson identified and named a third glaciation from the relatively thin Elatina tillite, of reddish chocolate colour, and directly underlying fossiliferous ‘Cambrian’ (Sprigg, 1949–1950; i.e. Ediacaran). This has latterly assumed importance with a magnetic nearequatorial palaeolatitude (Embleton & Williams, 1986; Schmidt, Williams & Embleton, 1991). This result triggered the snowball Earth hypothesis of Kirschvink (1992) and was confirmed by further work (Schmidt & Williams, 1995; Sohl, Christie-Blick & Kent, 1999). A palaeolatitude of 7.5◦ N was uniquely accorded ‘very reliable’ status by Evans (2000). The underlying Yaltepina Formation yielded a consistent palaeolatitude of 8.4◦ N.
Since Kirschvink's work in 1992, scientists have been uncovering mounting evidence that the surface of Earth almost completely froze at least a couple of times some hundreds of millions of years ago and developing ideas on just how this occurred. The big freezes or Snowball Earth events, with ice approaching the equator, are thought to have happened during the breakup of the huge continent Rodinia during a period 800 to 550 million years ago. Think about that. I'm not just talking about events that took place hundreds of millions of years ago. I'm talking about events that took place over hundreds of millions of years (during a 350 million year span), hundreds of millions of years ago (800 to 550 million years ago).
The break up of Rodinia caused silicate weathering that used up CO2 → Snowball Earth
Rodinia is the name given to the "supercontinent" thought to have existed more than 750 million years ago in the Neoproterozoic Era. Before breaking up, Rodinia would have comprised most of the land on Earth in one gigantic mass.
There was a lot of volcanic activity when Rodinia broke up, plus there was an increase in precipitation and runoff when it broke up. That's because of the greater number of sources of moisture along the borders of the broken bits of what was once Rodinia. (As one large land mass, most of Rodinia would have been too far from the sea, and would have been dry. More land masses means a greater total perimeter of land bordering the seas and more precipitation over land.) This in turn meant an increase in total silicate weathering which used up atmospheric CO2. It is proposed that atmospheric CO2 could have been reduced by 1,320 ppm in this way, from 1,830 p.p.m. to 510 ppm over time scales of around 10 million years. The sun was a lot fainter back then, so the global mean surface temperature is thought to have been around 4 °C lower than today before CO2 dropped to 510 ppm. That would make Earth about as cold as the most recent major ice age, and much colder than the Little Ice Age, before CO2 plummeted. So when CO2 dropped by a huge amount, almost the entire planet would have become iced up, hence the name Snowball Earth. (Refer Donnadieu04) It's thought that the global mean temperature could have dropped to around minus 50 °C. That's cold! (Refer Eyles and Januszczak 2004.)
Unzipping Rodinia - the zipper rift theory
In 2004, a paper by Eyles and Januszczak was published, in which they proposed a "zipper rift" theory to explain much about the Snowball Earth. They described it as:
Rifting began after 750 Ma as Laurentia progressively ‘unzipped’ from Rodinia to form the paleo-Pacific Ocean. A second phase of rifting and glaciation occurs at about 610 Ma when Baltica broke away from the eastern margin of Laurentia to form the Iapetus Ocean (paleo-Atlantic).The authors of the new paper have built on this "zipper rift" idea, and are proposing a mechanism that fills in some gaps in the Snowball Earth notion.
In other words, in contrast to what Anthony Watts seems to think, the authors are adding incremental ideas to an already developed idea that it was the reduction in atmospheric CO2 that caused the Earth to freeze, and an increase in CO2 that led to the unfreezing.
This new paper is primarily about detailed ocean chemistry and geology, to answer some of the questions that remain.
Geology and ocean chemistry
The geology part and the ocean chemistry part are inter-linked, as would be expected. The geology is about how volcanic eruptions along shallow mid-ocean ridges (unzippering) produced an enormous amount of glassy rock called hyaloclastite. Volcanic glass is thermodynamically unstable and can be rapidly changed by hydration to palagonite, a complex substance (of varying composition). By rapidly I mean days and months. Less than the blink of an eye geologically speaking.
One of the unanswered questions was about what caused the formation of thick cap carbonates. The Snowball Earth website explains cap carbonates. They are continuous layers of limestone (CaCO3) and/or dolostone (Ca0.55Mg0.45CO3), which are found overlying glacial deposits and sub-glacial erosion surfaces (where the glacial deposits are absent) from the Neoproterozoic era. Until now there had apparently been no satisfactory explanation for them.
This team's research suggests a mechanism. They propose that the hyaloclastite to palagonite conversion changes the ocean chemistry, releasing very large amounts of calcium, magnesium and phosphorus into the ocean. Because it was so cold, everything slowed down and the oceans became super-saturated and increasingly alkaline. From the press release:
Dr Gernon explained: “We calculated that, over the course of a Snowball glaciation, this chemical build-up is sufficient to explain the thick cap carbonates formed at the end of the Snowball event."The authors say that their hypothesis would answer a number of unresolved questions. Not all questions, but quite a few. They concluded writing (my paras):
The discovery that Earth experienced near-total ice cover for prolonged periods in the Neoproterozoic has greatly enhanced understanding of Earth history, but critical aspects remain unresolved. We demonstrate how enhanced shallow marine volcanic activity, persisting for >20 Myr in the absence of most biological removal processes, would have driven major changes in ocean chemistry.
Our shallow-ridge hypothesis advances understanding of Snowball Earth events. qualitatively and quantitatively explaining many enigmatic features including:And they provided a bonus relating to the emergence of multi-cellular life:
- increased ocean alkalinity;
- 13C-depleted cap carbonate sequences; and
- high silica concentrations manifest in banded iron formations.
Our hypothesis provides a critical quantitative explanation for unusually high dissolved phosphate inputs to late Proterozoic oceans. This enhanced supply may have driven the increase in primary productivity required to generate the large rise in atmospheric oxygen levels that occurred in the wake of Snowball Earth events. We infer that shallow-ridge volcanism associated with the Proto-Pacific and Lapetan rifts also prompted oxidation of the Ediacaran ocean , which would have facilitated the emergence of multicellular life.
From the WUWT comments
As usual, the WUWT comments ranged from the ridiculous to the supremely ridiculous, with the usual smattering of pseudo-science and paranoid conspiracy theorising.
January 18, 2016 at 11:28 am
As a “driver” CO2 causes volcanoes? Wow. A new low in grasping at straws.
markstoval doesn't have a clue what the scientists did or reported. It doesn't matter. He just fished into his bag of denier buzz phrases and punch in a random "thought":
January 18, 2016 at 11:29 amRob Dawg re-emerges to ask about the researchers' time machine, which he seems to think took them back 750 million years or so to the Snowball Earth:
This is what a former professor of mine would call a “SWAG”. That is a “scientific wild assed guess”. But in this case it is a bad, bad guess because CO2 does not have the magical powers those fools think it does. This is just horrible heifer dust “science”.
January 18, 2016 at 11:30 am
> “Because the land surface was then largely covered in ice, continental weathering effectively ceased. ”
How much time has the author spent several miles under an ice sheet to determine this?
sz939 goes all Dunning-Kruger, and decides that there was "Animal Life" long before Rodinia broke up. Well, of a sort - no-one's saying otherwise. He can't have heard of the "zipper-rift" theory of Eyles Januszczak (2004). He's also under the misapprehension that the authors claimed that hyaloclastite deposits "spontaneously convert to carbonates". They didn't. That's not what they were arguing. What they were saying was that because there was near global ice cover, normal removal processes were suppressed, and that a "prolonged state of hyaloclastite eruption and alteration (with the conversion to paragonite) would supersaturate sea water with Ca2+ and Mg2+". That's what would lead to subsequent large carbonate deposits.
January 18, 2016 at 11:31 am
Pardon me for raising the hand of skepticism here, but it should be noted that (1) Animal Life is well documented in the Precambrian Era, long before the time of Rodinia’s breakup; (2) One can’t have shallow marine volcanic deposits along Mid-Ocean Ridges as the ridge eruptions are by definition, the deepest ocean areas along a Mid-Ocean Ridge; (3) Dr. Gernon is a Populist Lecturer and by no means an acknowledged expert on Rodinia, Mid-Ocean Ridge Eruptions, or Subsea Volcanic Chemistry! His claims to fame involve Kimberlite Deposits, which are about as far from Mid-Ocean Ridge Eruptions as one can get. His ideas of subsea chemistry belie the facts that hyaloclastite deposits, which are by nature tufflike Glassy breccias, do not spontaneously convert to carbonates – at least so far anywhere else in the world where they form! Frankly, his claims amount to so much balderdash, that any competent volcanologist would have dismissed Dr. Gernon’s ridiculous notions as seemingly coming from some seriously deranged individual – which pretty much sums up those publishing from the University(?) of Southampton.
Ellen points out to sz939 that Iceland is part of the mid-Atlantic ridge.
January 18, 2016 at 2:53 pm
Iceland is an above-surface portion of the mid-Atlantic ridge. The valley of Thingvellir is spreading right in time with the ocean, and there is no shortage of volcanoes erupting. I’m not sure what the definition involved may be, but Iceland certainly isn’t the deepest part of any ocean.
ristvan thinks the authors are proposing biosynthesis of carbonate caps under "thick glacial ice". They aren't. They are proposing that biological activity resumes after the ice melts, not during the deep glaciation. The authors wrote: "In the glacial aftermath, conditions become more favourable for rapid precipitation: higher ocean temperatures, renewed photosynthesis. increased primary productivity. enhanced atmospheric C02 exchange and, importantly. resumption of particle settling providing carbonate condensation nuclei."
January 18, 2016 at 11:45 am
Read the abstract and SI; paper is paywalled. It is all computer simulations. MonteCarlo’s, no less!
And there is an apparent logic flaw. The simulations assume all this happens under thick ocean ice, which would prevent biosynthesis of the calcium carbonate caps he seeks to explain. No alternative abiological synthesis route is provided.
Nor does any of this explain why snowball earth melted thanks to enhanced volcanic CO2 (the abstract’s posited mechanism) since calcium carbonate sequesters CO2 until released by heating in subduction zones. A SWAG at best.
dbstealey appeals to a denier authority, claiming that Richard Lindzen claimed something or other. No evidence, naturally. (I doubt he did, but I could be wrong.)
January 18, 2016 at 3:47 pmPoor old lectrikdog is stuck in "CO2 lags temperature" and doesn't know that it doesn't always. He or she suffers from "scientists don't know nuffin'" syndrome so common to the denialati.
Interesting link (even though I tend to agree with Willis re: snowball earth).
Prof. Lindzen wrote that temperatures at the equator have not changed by 1ºC over the past billion years, so there’s no way that a true ‘snowball earth’ has happened in that time.
January 18, 2016 at 11:45 am
If CO2 always follows Temperature, then this theory could be wrong, or perhaps only misinterpreted. We know that CO2 is readily absorbed by cold seawater. In that case it has Zero atmospheric effect, but may promote Carbonate formation on seafloor sediments. The article does not specifically say that Oceanic CO2 outgassed and caused Atmospheric warming, nor does it define in terms of time and conditions what is meant by “the end of the snowball event”. It may not be so ridiculous. Oceans are shallower because a lot of water is locked up in the snowball.
As you know, most WUWT readers are greenhouse gas deniers, who are Anthony Watts' target audience. deebodk is one:
January 18, 2016 at 12:03 pm
“and reduced atmospheric CO2 levels, which increased global ice coverage and propelled Earth into severe icehouse conditions.”
I think the statement above pretty much lands this squarely in the ridiculous category.
Bubba Cow missed the biology class on phosphorus and, for a change, a few people jumped in and set him straight:
January 18, 2016 at 12:19 pm
“phosphorus” = “the catalyst for the origin of animal life on Earth” ??
I must have missed this class … unless someone can fix my ignorance
Richard is an "all or nothing" chap who doesn't understand the first thing about climate science. His wrong comment bore little relation to the article.
January 18, 2016 at 1:01 pmWhile poor freder wisse is cowering in fear, harbouring thoughts of deep paranoid conspiracies.
So, according to modern climate theory, all other factors mean nothing, not sun, not axial tilt, not volcanic activity. All climate change is because of the increase or decrease in carbon dioxide. It’s pretty amazing that, finally, an apparently complex and chaotic system is so fully understood to be neither, and that it all breaks down to one, simple, trace gas, which can be controlled easily by increasing taxes and regulating individual freedom.
January 18, 2016 at 1:38 pm
Carbon is the latest demonic fashion It is used nowadays to terrify the general public and to demand sacrifices It is the modern day continuation of the inca-madness. Computer models are used as a smoke-screen obscuring reality from too inquisive minds .Good luck with this superstition . Obama does not make a mistake calling.climate change the most urgent problem nowadays except that he is using a false narrative . .
References and further reading
T. M. Gernon, T. K. Hincks, T. Tyrrell, E. J. Rohling & M. R. Palmer. "Snowball Earth ocean chemistry driven by extensive ridge volcanism during Rodinia breakup." Nature Geoscience Advance Online Publication doi:10.1038/NGEO2632 - with the press release from the University of Southampton: Explosive volcanism drove major changes in ‘Snowball Earth’ ocean chemistry
Harland, W. Brian. "Origins and assessment of snowball Earth hypotheses." Geological Magazine 144, no. 04 (2007): 633-642. doi:10.1017/S0016756807003391 (pdf here)
Mawson, D., 1949. "The Elatina glaciation: a third recurrence of glaciation evidenced in the Adelaide system". Trans. Geol. Soc. S. Afr. 73, 117– 121.
Kirschvink, J.L., 1992. Late Proterozoic low-latitude global glaciation: the Snowball Earth. In: Schopf, J.W., Klein, C. (Eds.), The Proterozoic Biosphere, A Multidisciplinary Study. Cambridge
Univ. Press, Cambridge, pp. 51– 52. (pdf here) - with a human interest article about what led to this work on the website The Snowball Earth.
Hoffman, Paul F., Alan J. Kaufman, Galen P. Halverson, and Daniel P. Schrag. "A Neoproterozoic snowball earth." science 281, no. 5381 (1998): 1342-1346.
Donnadieu, Yannick, Yves Goddéris, Gilles Ramstein, Anne Nédélec, and Joseph Meert. "A ‘snowball Earth’climate triggered by continental break-up through changes in runoff." Nature 428, no. 6980 (2004): 303-306. doi:10.1038/nature02408 (pdf here)
The Slow Carbon Cycle - article on NASA's Earth Observatory website
Jakobsson, S. P. "Subglacial and submarine volcanism in Iceland." In Second International Conference on Mars Polar Science and Exploration, vol. 1, p. 85. 2000. - a paper that has some discussion about hydroclastite and its conversion to paragonite.