From the Institute of Physics , something so overreaching I just can’t believe the Institute of Physics would put out a press release on it. Where does one start with stuff like this? This is all modeling, they haven’t even tested any actual sea ice to see if it follows the theory. Their premise would be easy to test with some glacier water, a freezer, a controlled gaseous CO2 source, and a tensile/ductile strength mechanical force tester for brittleness. But that sort of basic testing wasn’t done. Yet, they equate their modeled posited effect to be the cause of the Pine Island Glacier breakoff, as if somehow events like that never happened before CO2 was at 392PPM. Note the abstract and link to the paper below. – Anthony
The well-documented presence of excessive levels of carbon dioxide (CO2) in our atmosphere is causing global temperatures to rise and glaciers and ice caps to melt.
New research, published today, 11 October, in IOP Publishing’s Journal of Physics D: Applied Physics, has shown that CO2 molecules may be having a more direct impact on the ice that covers our planet.
Researchers from the Massachusetts Institute for Technology have shown that the material strength and fracture toughness of ice are decreased significantly under increasing concentrations of CO2 molecules, making ice caps and glaciers more vulnerable to cracking and splitting into pieces, as was seen recently when a huge crack in the Pine Island Glacier in Antarctica spawned a glacier the size of Berlin.
Ice caps and glaciers cover seven per cent of the Earth—more than Europe and North America combined—and are responsible for reflecting 80 per cent of the Sun’s light rays that enter our atmosphere and maintain the Earth’s temperature. They are also a natural carbon sink, capturing a large amount of CO2.
“If ice caps and glaciers were to continue to crack and break into pieces, their surface area that is exposed to air would be significantly increased, which could lead to accelerated melting and much reduced coverage area on the Earth. The consequences of these changes remain to be explored by the experts, but they might contribute to changes of the global climate,” said lead author of the study Professor Markus Buehler.
Buehler, along with his student and co-author of the paper, Zhao Qin, used a series of atomistic-level computer simulations to analyse the dynamics of molecules to investigate the role of CO2 molecules in ice fracturing, and found that CO2 exposure causes ice to break more easily.
Notably, the decreased ice strength is not merely caused by material defects induced by CO2 bubbles, but rather by the fact that the strength of hydrogen bonds—the chemical bonds between water molecules in an ice crystal—is decreased under increasing concentrations of CO2. This is because the added CO2 competes with the water molecules connected in the ice crystal.
It was shown that CO2 molecules first adhere to the crack boundary of ice by forming a bond with the hydrogen atoms and then migrate through the ice in a flipping motion along the crack boundary towards the crack tip.
The CO2 molecules accumulate at the crack tip and constantly attack the water molecules by trying to bond to them. This leaves broken bonds behind and increases the brittleness of the ice on a macroscopic scale.
Carbon dioxide enhances fragility of ice crystals
Zhao Qin and Markus J Buehler 2012 J. Phys. D: Appl. Phys. 45 445302 doi:10.1088/0022-3727/45/44/445302
Abstract:
Ice caps and glaciers cover 7% of the Earth, greater than the land area of Europe and North America combined, and play an important role in global climate. The small-scale failure mechanisms of ice fracture, however, remain largely elusive. In particular, little understanding exists about how the presence and concentration of carbon dioxide molecules, a significant component in the atmosphere, affects the propensity of ice to fracture. Here we use atomic simulations with the first-principles based ReaxFF force field capable of describing the details of chemical reactions at the tip of a crack, applied to investigate the effects of the presence of carbon dioxide molecules on ice fracture. Our result shows that increasing concentrations of carbon dioxide molecules significantly decrease the fracture toughness of the ice crystal, making it more fragile. Using enhanced molecular sampling with metadynamics we reconstruct the free energy landscape in varied chemical microenvironments and find that carbon dioxide molecules affect the bonds between water molecules at the crack tip and decrease their strength by altering the dissociation energy of hydrogen bonds. In the context of glacier dynamics our findings may provide a novel viewpoint that could aid in understanding the breakdown and melting of glaciers, suggesting that the chemical composition of the atmosphere can be critical to mediate the large-scale motion of large volumes of ice.
Introduction
Ice caps and glaciers cover 7% of our planet, greater than the land area of Europe and North America combined [1]. They reflect 80–90% of the solar radiation and trap a large
amount of carbon dioxide. Specifically, the Arctic accounts for 10–15% of the earth’s carbon sink [2]. The glaciers’ dynamical behaviour and stability play important roles in controlling the global climate [3, 4]. Thereby, the facture mechanism of ice is of paramount importance for the understanding of glacial dynamics [5], and at a fundamental level is controlled by how a single crack propagates in ice crystals via the
breaking of chemical bonds [6]. Such growth of cracks eventually mediates the breakdown of ice, as exemplified in recent incidents of large-scale fracture of glaciers [7, 8]. Very
large-scale ice fractures occurred recently close to the Pine Island Glacier in the Antarctic region, which generated an iceberg with an area of around 880 square kilometres, the size
of the city of Berlin [9].
While the macroscopic mechanical properties of pure ice are well understood by laboratory tests and its behaviour has been characterized by existing fracture
mechanics models [10], the effect of environmental conditions such as the concentration of carbon dioxide, have not been incorporated into existing models. Lack of such knowledge prevents us from understanding how changes in the chemical environment affect the stability and movement of glaciers, which is important given the rising levels of carbon dioxide in the atmosphere.
[Suggestion: do some laboratory testing to get the same level of understanding]
…
Conclusion
Using atomic simulations with the ReaxFF reactive force field, we investigated the effect of carbon dioxide on the fracture behaviour of ice. We find that the material strength
and fracture toughness are decreased significantly under increasing concentrations of carbon dioxide molecules. This phenomenon is caused by the interaction between water and carbon dioxide molecules. Carbon dioxide molecules first adhere to the crack boundary by forming hydrogen bonds, and then migrate along the crack boundary towards the crack tip.
The dissociation energy of hydrogen bonds at the crack tip is decreased under the attack by carbon dioxide. This migrationattacking process repeats itself and renders the ice crystal more brittle by mediating crack propagation. Our theoretical model quantitatively accounts for the effect of carbon dioxide on the surface energy and fracture toughness of ice. It could be instrumental for further studies of ice fracture in various chemical environments and may be scaled up by incorporating it into models of glacier dynamics.
paper here (you may need to register for free account to read it)
http://iopscience.iop.org/0022-3727/45/44/445302/pdf/0022-3727_45_44_445302.pdf
Related articles
- S. African Scientist Kelvin Kemm: Glacier melting is not caused by global warning: ‘To melt ice, the temperature has to go up past 0 ºC to at least ‘plus something’ (climatedepot.com)
- Thwaites Glacier Tongue Major Calving Event, Antarctica (glacierchange.wordpress.com)
Let’s ignore this badly thought through statement that: “Ice caps and glaciers cover 7% of our planet, greater than the land area of Europe and North America combined [1]. They reflect 80–90% of the solar radiation and trap a large amount of carbon dioxide.” Let’s look at the funding source: Air Force Office of Scientific Research and DoD Presidential Early Career Award in Science & Engineering. Thanks guys, you really care about spending our tax dollars to perform superior and needed research!
Experiment: seltzer water, sea salt, freezer. Works for me.
garymount says:
October 11, 2012 at 2:12 am
Obviously CO2 is plant and duck fertilizer.
Did they actually first attempt to prove whether the gases were from the atmosphere or from below? The crack is not consistent with the gas weakening the ice and it breaking as much as it forming a bubble below the ice so it was no longer supported by water and therefore stressed too much to support its own weight. The horizontal crack in the picture is the type you would expect to see if it was storm damage without the compression damage either side.
Probably they did not look not because research into natural not man made environmental situations is not covered by the fat global warming budgets and would have to be met from the meagre resources available to the plate tectonics and similar departments even after the Russians have found one case of this type of gas source without even looking suggesting it is a common situation.
AlecM says:
October 11, 2012 at 5:11 am
I’m not familiar with the sort of simulation software they’re using, but I wouldn’t be surprised if they were simulating a small ice crystal that has no defects, say 100x1000x1000 molecules large. That’s still 100 million molecules, or 300 million atoms, to track.
If so, this would have little to do with jumbled arrangement of crystals and impurities when the glacier formed, let alone what creep has done to it, nor would it have anything remotely like the torque forces on the full glacier.
I won’t have time to read the paper, does it describe stuff like the salt and dust content of the ice shelf and their simulation?
Perhaps they really meant to say: ice cover reflects 80% of the light striking its surface. This inability to properly express a simple principal, reflects very badly on their understanding. GK
Sorry I posted it before I had finished and was about to ask if anyone knew if the were any known gas fields in the area.
While I am about it can anyone answer this question.
Since it is supposed to be possible to distinguish man made CO2 from natural using carbon 14 does this show an increase that matches the use of fossil fuels or has it more or less stabilised at a given percentage and if so what is that figure? Why I ask is that if it is flattening it would suggest that the natural systems create and use the gas and that man’s input is just one factor which would be treated like the others so the end figure is nearly independent of man’s activity not the panic making unstable addition suggested by climate scientists.
Those Polar bears sitting on those ice flows better stop opening up bottles of Coca-Cola.
LeeHarvey says:
October 11, 2012 at 5:24 am
We can now go on pondering the effect of clouds.
http://www-das.uwyo.edu/~geerts/cwx/notes/chap08/cloud_lat.html
Ok, so let’s assume 70% for South pole and 90% for North pole. As the South pole stays ice-covered there’s no effect on albedo there. The effect during North pole summer is diminished by a factor of 10 due to the cloudiness. So even during North Pole summer, only 0.11% of Solar radiation could reach water at the North pole where there was ice in the past.
Now we need to consider the reflexion of low incident angle light. Unfortunately, nobody seems to have measured it, at least I can’t find it; the waviness influences the absorption; a totally flat surface would reflect totally due to the low angle of the sun. So let’s assume about 90% absorption and we can say that the effect is:
a maximum of about 0.1% of Solar radiation could be absorbed by North polar sea where there was ice in the past. That’s a Watt a square meter averaged across the globe.
Of course, this effect is the maximum possible if ALL ice is gone; if only a part is gone, it needs to be put in relation. We have a new minimum of 3 mill km^2 instead of 6 mill km^2 average summer minimum; 6 mill km^2 are about 1.2 % of the surface area of the Earth; 3 mill km^2 difference is 0.6%.
You initially assumed 3.5 % for one ice cap. (7% for both) But the observed difference during NH summer is only 0.6% so the calculated effect can safely be assumed to be about 6 times weaker.
We get to:
a maximum of about 0.017% of Solar radiation could be absorbed by North polar sea where there was ice in the past during NH sea ice minimum. That’s a momentary 1/6th of a Watt/m^2 surplus absorption, averaged across the globe.
My brain is starting to crack from being exposed to lazy, shoddy science research. Can I sue?
Pray tell, what are these authors doing, giving us a sermon about all the ice on the planet the size of Berlin, and other inconsequential factoids; in order to present some atomic Physics about CO2 competing with H2O in ICE crystals. Did they for comparison investigate the disruptive role of H2O molecules in say Dry ice crystals; maybe that’s why we don’t get CO2 snow at the South pole; all that H2O molecules weakens the dry ice crystals at grain boundaries, so they fall apart.
Now maybe this atomic physics modelling is all very interesting, especially if it can get you grant money from the tax payers; but what effect did it have in geologic times in preventing the ice ages from happening.
I just tried exhaling onto the ice tray in my frig, and so far none of the cubes has fallen apart. Should be good when my evening Sangria time comes around.
“””””…..Ice caps and glaciers cover seven per cent of the Earth—more than Europe and North America combined—and are responsible for reflecting 80 per cent of the Sun’s light rays that enter our atmosphere and maintain the Earth’s temperature. …..”””””
Well I have never been anywhere near MIT, but even I know that this statement is pure bullsh*t.
Just for starters, 1362 W/m^2 arrive at the earth from the sun, and about 1000 W/m^2 arrives at the surface, about 70% of which is the oceans.
So there is no way in hell, that ANYTHING is reflecting 80% of the sun’s light rays that enter our atmosphere.
As for ice, even at its finest, ice does not reflect 80% of visible light. Ice which may have started off as snow, does very little reflecting, but a lot of scattering at first, and a good deasl of the light propagates into the interstices between the snow crystals, so that after just a few hours of exposure, the surfaces have melted, creating optically transparent facets, which will transmit around 97-98% of incident sunlight, and once inside, the ice, it is largely trapped by Total Internal reflection. Consequently the apparent “reflectance” of snow can drop below 40% in just a few hours after deposition.
And of course to be pedantic, “light” rays do NOT enter the earth atmosphere; EM Radiation that is visible does enter the earth’s atmosphere, but “light” exists only in our eyes and brain; which is why we quantify it in Lumens and related units, rather than Joules, which we use for energy.
We get just as much light from the sun, as we do heat; namely NONE. We make ALL of our heat here on earth, and we make ALL of our light, in our brain.
I remember reading an item on BBC Red Button a while ago that ‘scientists say that the ice is just sliding off Antarctica and they do not know why nor what this will mean for sea levels.’ The implication is obvious but I thought advancing glaciers accounted for that very nicely. Would this to be the latest attempt to use the inconvenient fact that the ice at the south pole appears to be increasing for their own ends?
Maybe there’s a giant CO2 “laser” mounted on the moon, pointed directly at the polar ice…
pew pew pew!!!
Ice above a threshold pressure flows like an extremely slow and viscous liquid. Glaciers consist of a brittle surface layer, above a flowing plastic layer once the weight of ice above is enough. When a glacier flows out over water, the lower parts are at high pressure and still plastic. As the ice melts and gets thinner, the thickness of the brittle layer remains constant while the plastic layer thins, until eventually the plastic layer reduces to zero, and the tip of the ice shelf breaks off.
If this breakage were to happen a few hours earlier, it would make no difference to anything. The flow of glaciers is determined primarily by what goes on in a layer where cracks do not form anyway, so a study of cracks is irrelevant.
Cargosquid says:
October 10, 2012 at 10:09 pm
“The consequences of these changes remain to be explored by the experts, but they might contribute to changes of the global climate,”
BWAAHAHAHAHAHAHAHAHAHAHA! I’m not a scientist. I don’t even have a degree. But I know that if I had THAT statement on any science paper during my years in HIGH SCHOOL, I’d get a failing grade.
And, as a non-credentialed man….what exactly is the energy being used to break those hydrogen bonds in favor of CO2……And wouldn’t the hydrogen be bonding with the Oxygen in the CO2? And isn’t that also a hydrogen bond…and where does the carbon fit in during all this new “bonding?” Do we now have CH2O2? CH2O? What molecule is being formed?
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I think you misunderstand what a hydrogen bond is. It’s not a chemical bond where atoms are bound to each other by sharing electrons and so form a molecule. It is more like a weak magnetic attraction of the slightly positive hydrogen atoms in H2O to another slightly negative atom. It doesn’t form a new molecule but loosely links molecules together. Both molecules remain intact and unchanged but they are loosely “stuck” to each other. A water molecule is “V” shaped with the Oxygen at the bottom of the “V” and the Hydrogen at the tips. The more heat (energy) there is, the faster the molecules of H2O will move around and bounce off each other. As the heat is removed the molecules slow down and get closer. The water becomes denser. All compounds will do this but with water, once you get to 32*F, the hydrogen bonds begin to form between the Hydrogen of one molecule and the Oxygen of others. Because of the “V” shape of a H2O molecule a crystal structure is formed (ice) that is actually less dense than liquid H2O. That’s why ice floats. When other liquids reach their freezing point and become a solid, they sink because they remain denser than the liquid.
A CO2 molecule is not “V” shaped but is more in a line. O-C-O. What this paper seems to be claiming is that the Hydrogen bond that links H2O to H2O molecules together to form ice is being interfered with by the Oxygen in CO2.
Re Bob and Jim Turner
You have raised the most important issues with this paper. The study looked at pure water Xtals, and this is unlikley to be representative of how the CO2 disruption will occur in actual Xtals that are not from pure water. That and the level of CO2 that they used pretty much exclude it from real life simulations. It is an interesting paper but certainly not a Nobel Prize winner that has anything to do with actual ice life cycle in the cryosphere. I would not expect it to get too much attention by serious AGW researchers.
“They are also a natural carbon sink, capturing a large amount of CO2.”
Wondering if melted water would not capture more CO2 then ice does?
The press releases says: “Ice caps and glaciers cover seven per cent of the Earth—more than Europe and North America combined—and are responsible for reflecting 80 per cent of the Sun’s light rays that enter our atmosphere”.
The abstract says: “Ice caps and glaciers cover 7% of our planet, greater than the land area of Europe and North America combined [1]. They reflect 80–90% of the solar radiation”.
There is a big difference. The above statement in the press release is nonsense, as many have pointed out. The statement in the abstract is different. “They reflect 80-90%”, they being the ice caps and glaciers. Of the sunlight that hits ice and glaciers, 80-90% is reflected and 10-20% is being absorbed. This could be true.
It seems that the writter of the press release did not read the abstract that well.
So, dissolved CO2 would decease the surface tension of water and thus decrease the latent heat of evaporation and thus cause greater evaporation for a given radiation power?
Rattus Norvegicus said on October 10, 2012 at 6:51 pm:
Note to self:
Add to personal thesaurus:
Clump generated by cat as found in litter box: hypothesis
I tell you, it’s not the CO2 – it’s the dreaded dihydrogen monoxide.
I mean, the ice is just full of the stuff.
Ice cracks when its put under stress. I’m willing to bet the effect of the stress that cracks the ice in the case of the Pine Island Glacier and others is many orders of magnitude greater than any “excess CO2” effect.
I think this blog is reasonably accurate. Computer simulations are responsible for much of our knowledge of earth’s systems today because it is simply not possible to consider all of the processes which are affecting our planets systems. In this case, the effect of CO2 cannot be experimented on to the macro-scale of Ice caps and therefore an attempt to do so would be faulty. We are therefore left with hypothesizing a process using computer simulations and concluding beyond reasonable doubt that CO2 effects Hydrogen bonds in the ice.
Icemania says:
October 12, 2012 at 4:17 am
I think this blog is reasonably accurate.
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I think not Icemania. It has some major errors:
1) “ice caps and glaciers … are responsible for reflecting 80 per cent of the Sun’s light rays that enter our atmosphere and maintain the Earth’s temperature.”
nonsense
2) “They are also a natural carbon sink, capturing a large amount of CO2.”
wrong, the quantity of CO2 that dissolves into water is far greater that the CO2 captured in ice. the reference cited says a different thing: “the Arctic accounts for 10–15% of the earth’s carbon sink ” which is not in the ice in the Arctic.
3) what concentrations of CO2 were used in the model and what was the observed difference in model? Jim Turner made it very clearly in his post above:
http://wattsupwiththat.com/2012/10/10/untested-claim-increased-co2-helps-glacier-ice-to-crack/#comment-1106791
4) what validation was done for the model? None.
5) “well-documented presence of excessive levels of carbon dioxide (CO2)”
It starts with a lie. CO2 is not excessive in our atmosphere. Reducing the CO2 level from now to any level would mean to reduce the biosphere. So excessive for whom?
The blog is not accurate in my eyes, is CAGW-propaganda.
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R. Shearer says:
October 10, 2012 at 6:52 pm
This could explain why ice core analysis for CO2 is biased low an underestimates historical CO2 levels.
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Very interesting point R. Shearer. Jaworowsky illustrated the problems with using ice core bubles as proxy for CO2 concentration at the time, and this links to his study.
As Ferdinand said a couple of posts below – would the CO2 not tend to run towards the minimum concentration? We know the “outside of the glacier”=the atmosphere having great CO2 variations. Question is how the equilibrium between the CO2 “from inside” and the CO2 “outside” is done, if the difficulty or the easiness to migrate in and out are the same.
As for the CAGW-theorists modelling is true data, they will certainly take these results and incorporate in the future models and find even more dramatic effects. “It is worse then we thought” … in their future modelled sim-world.