We covered this topic before on WUWT, but it showed up again in this week’s AGU highlights. Given the attention to the recent Arctic sea ice low and quick turnaround, I thought it would be appropriate to mention again.
From the American Geophysical Union highlights
The Arctic has been losing sea ice as Earth’s climate warms, and some studies have suggested that the Arctic could reach a tipping point, beyond which ice would not recover even if global temperatures cool down again. However, a new study by Armour et al. using a state-of-the-art atmosphere-ocean global climate model finds no evidence of such irreversibility. In their simulations, the researchers increase atmospheric carbon dioxide levels until Arctic sea ice disappears year-round and then watch what happens as global temperatures are brought back down. They find that sea ice steadily recovers as global temperatures drop. An implication of this result is that future sea ice loss will occur only as long as global temperatures continue to rise.
Source: Geophysical Research Letters, doi:10.1029/2011GL048739, 2011 http://dx.doi.org/10.1029/2011GL048739
Title: The reversibility of sea ice loss in a state-of-the-art climate model
Authors: K. C. Armour: Department of Physics, University of Washington, Seattle, Washington, USA;
I. Eisenman: Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA, and Department of Atmospheric Sciences, University of Washington, Seattle, Washington, USA;
E. Blanchard-Wrigglesworth, K. E. McCusker, and C. M. Bitz: Department of Atmospheric Sciences, University of Washington, Seattle, Washington, USA.
Key Points
- Sea ice loss is reversible within a state-of-the-art global climate model
- We find no evidence of threshold behavior in summer or winter sea ice cover
- Rapid sea ice retreat does not imply irreversibility
Abstract:
Rapid Arctic sea ice retreat has fueled speculation about the possibility of threshold (or ‘tipping point’) behavior and irreversible loss of the sea ice cover. We test sea ice reversibility within a state-of-the-art atmosphere–ocean global climate model by increasing atmospheric carbon dioxide until the Arctic Ocean becomes ice-free throughout the year and subsequently decreasing it until the initial ice cover returns. Evidence for irreversibility in the form of hysteresis outside the envelope of natural variability is explored for the loss of summer and winter ice in both hemispheres. We find no evidence of irreversibility or multiple ice-cover states over the full range of simulated sea ice conditions between the modern climate and that with an annually ice-free Arctic Ocean. Summer sea ice area recovers as hemispheric temperature cools along a trajectory that is indistinguishable from the trajectory of summer sea ice loss, while the recovery of winter ice area appears to be slowed due to the long response times of the ocean near the modern winter ice edge. The results are discussed in the context of previous studies that assess the plausibility of sea ice tipping points by other methods. The findings serve as evidence against the existence of threshold behavior in the summer or winter ice cover in either hemisphere.
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I’d really like somebody to show me that these tipping points exists anywhere except in a computer model or a grant proposal for more funding.
Irreversible!! Irrepressible more like.
I invite everyone to look at those amazing NOAA Arctic timelapse sequences of freeze and thaw…watch especially the rushing currents transporting ice into the oceans and the ease with which it is replenished. …it should be quite obvious to anyone that the Arctic can and will keep pumping out ice until the earth shifts on its axis and there is no longer 3 months of sub-zero darkness.
“higley7 says:
September 21, 2011 at 6:08 am ”
Just what I was thinking. This paper supports the skeptical position but it is still beyond crap so endorsing it would be hipocritical. Sorry pseudoscience, you lose. Even the Team will hate you this time, it’s the wrong flavor of pseudoscience.
How about peer reviewing the peer reviewers?
•Antonio Zichichi, nuclear physicist and President of the World Federation of Scientists: “In the past half billion years, Earth has lost, four times, its polar caps – no ice at either Pole. And, four times, the polar caps were reconstituted. Global warming is caused by unusually high levels of solar radiation and a lengthy – almost throughout the last century – growth in its intensity
liontooth says:
September 21, 2011 at 4:24 am
“Are there any planned archaeological expeditions in the future to these new ice-free areas in Greenland? Surely something interesting is to be found where no man has ever gone before.
Would actual evidence that humans did set foot in these unprecedented ice-free areas during the Medieval Warm Period be “inconvenient”?”
Yeah, it would.
From the following post/article “…archaeologists had to dig through the permafrost to get at the old Viking farm houses shows…”
The Fate of Greenland’s Vikings and the falsification of human induced global warming
http://fgservices1947.wordpress.com/2011/07/23/the-fate-of-greenlands-vikings-and-the-falsification-of-human-induced-global-warming/
DOH !!!!!!!!
Tired of hearing “Tipping Point” !!!!!!!!!!
Should be banned from language !!
A number of people here are identifying the paper as helpful to the sceptic cause. I don’t agree as in the paper a recovery of ice extent rests *entirely* on reducing CO2 to reduce temperature. They aren’t suggesting summer ice won’t disappear, they are saying it will unless we limit atmospheric CO2 levels to limit temperature.
Ice Loss is a pathetic, non-scientific phrase. That water is going nowhere fast. It is not ‘lost’.
Once again, unless the Earth gets whacked bad by an enormous object and knocked onto its side like Uranus, the axial tilt means it will remain as is, alternating between cold and very cold up there, forever. The current configuration leads to sun up / sun down for long periods each, causing above freezing and below freezing temperatures, which in turn leads to clockwork phase changes between water and ice. This will never be defeated by CO2 levels of any magnitude.. Never! The alarmists have worked themselves up over ice extent occurring during a timespan of perhaps one week out of 52 in a year.
You want to melt all the ice? Remove the land preventing warmer water into the Arctic. Or, change the axial tilt. CO2? Not a chance. _Wiki_
“The Arctic has been losing sea ice as Earth’s climate warms, and some studies have suggested that the Arctic could reach a tipping point, beyond which ice would not recover even if global temperatures cool down again.”
Things may get very hot or very cold and it may take thousands of years to get back to ‘normal’, whatever that may be, but there are no tipping points.
I believe Lubos’ article on Le Chatelier’s principle and climate would be an interesting read for these people: http://motls.blogspot.com/2007/11/le-chateliers-principle-and-natures.html
From this article:
“But the idea that positive feedbacks dominate or that they are the ones who win at the end simply contradicts basic laws of thermodynamics.”
>>DOH !!!!!!!!
>>Tired of hearing “Tipping Point” !!!!!!!!!!
>>Should be banned from language !!
Take heart with this. We’ve already passed one “tipping point” without evidence that anything tipped over. However, the THEORY of AGW has leaned a little more (kind of like the Leaning Tower of Pisa), and they still keep predicting more climate tipping points. One day the theory will fall all the way over no matter what they do to keep it propped up.
I think these “tipping points” are actually an unconscious projection by the global warming faithful about what is happening to their cherished belief system. That’s how it works with deluded people.
Remember what happened the following year 2008?The ice came back with vengance.The the global warming crowd was trying to disprove the ice report by saying it was a glitch in the system.When the ice increases ,as is doing ,they want to say it thin ice or young ice.
I agree with Another Gareth’s comment.
The observed warming is clearly due to natural processes
e.g. see
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
and some additional warming (on top of the natural warming) is caused by increased vegetation
Limiting CO2 (a natural non-poisonous gas) in the atmosphere is stupid
And in the accompanying “Arctic Sea Ice Concentration” graphic, why are areas beyond the Arctic Circle included—particularly Hudson Bay, the Sea of Okhotsk, the Bering Sea, and the Gulf of Saint Lawrence?
How much co2 did they factor in before the ice melted entirely ?
Dave Springer says:
September 21, 2011 at 3:39 am
/////////////////////////////////////////////////////
As I have commented many many times, climate scientists never seem to look at history. For example, just consider the Viking settlements on Greenland and what that tells us about temperatures in high northern latitude, and ice/glacial extent 9a soewhat topical matter given the latest edition of the Times Atlas)..
Further, it is almost certainly the case that the climate must self regulate, if not, we would not be here today (some 4.5 billion years after the formation of the Earth) given the varied and tumultuous past history of the Earth (eg., a core substantially hotter than today, extremely active volcanos, bombardment by asteroids, comets, may be even a snowball Earth, may be even an Earth with no ice at the poles etc. etc);. It is clear that planet Earth is one hell of a survivor. As such, it is extemely improbable that there are any irreversible tipping points (at any rate not within reasonable bounds).
It is startling how cliamte scientists rediscover the wheel and may only just have appreciated that water will freeze when it gets cold enough no matter how hot the water may have been in the past. They could have averted the need to explore this issue by way of supercomputer and fiendishly sophsticated models simply by boiling a kettle, pouring the boiling water into a cup, putting the cup in the freezer, waiting a few hours and hey presto, you guessed, we have ice. After all this is one of the ‘settled science’ properties of water,
I guess that commonsense is too much to expect. I wonder how much CO2 was emitted consequential to that research and the publicaton of the paper.
What annoys me most are the blocking patterns which allow arctic outbreaks, and drain the pole of all its bitter cold. Then not only do I freeze my -bleep- off, but I have to listen to Alarmists gloat that it is “warmer-than-normal” at the pole.
I prefer today. Nice pool of cold air stuck; smack, dab over the pole. Up there it is minus fifteen (C) which is an anomoly of nearly minus twenty (F.) Alarmists sulking as everything freezes up, up there, but nice and balmy in my back yard, in southern New Hampshire.
But now I suppose they’ll switch the subject and get all alarmed about it being above normal in southern New Hampshire. Well, I”ll not let them spoil a golden day. If they change the subject I’ll change the channel.
Actually that wouldn’t be a half-bad bumper sticker:
Fight Global Warming.
Turn Off The News.
Werner Brozek says:
September 21, 2011 at 8:26 am
“The Arctic has been losing sea ice as Earth’s climate warms, and some studies have suggested that the Arctic could reach a tipping point, beyond which ice would not recover even if global temperatures cool down again.”
Things may get very hot or very cold and it may take thousands of years to get back to ‘normal’, whatever that may be, but there are no tipping points.
I believe Lubos’ article on Le Chatelier’s principle and climate would be an interesting read for these people: http://motls.blogspot.com/2007/11/le-chateliers-principle-and-natures.html
Unfortunately Lubos misapplies Le Chatelier’s Principle, whether he doesn’t really understand it or is just doing so deliberately I know not.
http://www.straferight.com/photopost/data/500/medium/double-facepalm.jpg
Sigh, Studies like this again relying on models, are meaningless. You program into the model the accepted parameters and the expected outcome is arrived at based on that.
Lets say you create a model of the stock market. It is not really any more or less chaotic then the eco system. Would you do what the models suggest you do? I do model things and I sure would not. Modeling helps to describe what might happen or does happen but by golly it is hard to get it right. If a prediction occurs within a range of +-5% I am stoked!
I wonder how many taxpayer, if any, think that they are getting good value for their tax dollars fundng such “studies”. I can assure you I think we are being robbed. It is a license to steal.
1 – Models are computer programs. Computer programs do what they are programmed to do. If a model outputs certain results, that’s because that’s how the model was programmed.
2 – Models do not output data. Models do not output facts.
Ok, time for a stupid question. Given that the Arctic ice does disappear completely, what are the real-world consequences? Not the hyperbolic “end of the world” stuff, but expected value predictions?
Tipping Point thinking:
“OK, there’s no monster under the bed right now. But sometime soon there might be!”
“Phil. says:
September 21, 2011 at 10:01 am
Werner Brozek says:
Unfortunately Lubos misapplies Le Chatelier’s Principle, whether he doesn’t really understand it or is just doing so deliberately I know not.”
Trust me, Lubos completely understands Le Chatelier’s Principle and I do as well. (I have an engineering degree.) We know how it applies to basic chemical systems when a single variable such as temperature, pressure, and concentrations changes. However indications are that it applies to climate as well.
To give two concrete examples, according to how much CO2 man is putting into the air every year, only half shows up in the atmosphere. That is because photosynthesis uses more than normal and much CO2 gets dissolved in the oceans.
Then Earth’s temperatures are not rising nearly as fast as the models believe they ought to be. That is because the feedbacks due to clouds are negative and not positive.
Furthermore, Earth has been around for 4.5 billion years and it is very suitable for life right now.
So I agree that while Le Chatelier’s Principle basically just applies to simple systems, I believe a much more complicated set of Le Chatelier’s types of Principles could be developed for climate, but we are not there yet. Many pieces of the puzzle are still missing, but papers like SB11 fill in some of the pieces.