RealClimate

Comments

RSS feed for comments on this post.

  1. It may be the focus on sea ic extent itself is misleading. Actic sea ice VOLUME hit a record low in August 2011, one month before the minimum.

    By the minimum ice volume measure, last year’s (2010) September measure was the previous record holder, with September 2007 is third place.

    See:
    http://neven1.typepad.com/blog/2011/09/piomas-august-2011.html

    In fact minimum arctic sea ice volume is falling much faster – and may be more important – than minimum sea ice extent.

    Comment by Bruce Tabor — 9 Sep 2011 @ 6:53 AM

  2. In my above post on a new record minimum arctic sea ice volume I should have linked the original source of the data, which is here:

    http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

    Comment by Bruce Tabor — 9 Sep 2011 @ 7:18 AM

  3. Bruce, that is a good point, very similar to Roger Pielke Sr.’s insistence that global temperature series is an inferior metric to ocean heat content, except that our records of sea ice extent go back much further and are better calibrated than for volume, as our records of global temperature go back much further. The perfect is often enemy of the excellent.

    Further, wrt the ice-albedo feedback it is the extent that governs.

    Comment by Eli Rabett — 9 Sep 2011 @ 7:19 AM

  4. This is an interesting piece about the importance of feedback mechanisms in the Arctic. From the last few lines a very ironic conclusion can be drawn: there is not only an ice-albedo feedback, but (at least theoretically) also an ice – fossil-fuel-exploration feedback.

    Comment by Martijn de Ruyter de Wildt — 9 Sep 2011 @ 7:39 AM

  5. @Bruce Tabor

    The ice volume change is less relevant to the ice-albedo feedback, where the relative proportions of ice covered to ice free ocean dominate the radiative effect. Reducing ice thickness (volume) will serve to make the system more sensitive to melting (and further area loss and radiative feedback) but as mentioned in the Tietsche et al paper this will be rapidly recovered from.

    Comment by Alex Thomas — 9 Sep 2011 @ 7:39 AM

  6. The USGS estimates an equivalent of 3 years of current world wide human oil consumption in the Arctic which is close to one year of all anthropogenic CO2 emissions into the atmosphere; not counting trillions of cubic feet of natural gas also assumed in the Arctic. I wonder whether the forcing of this additional positive feedback effect evoked by exploited Arctic resources has been included in the model shown above.

    However, the model run of 2060 substantiates sea ice can not recover once the climate is ruined. The Kara Sea was already ice free very early this year. Is it just irony best adaptor to a changing climate is the oil industry? Ultimately it is up to me to choose a clean energy provider.

    Comment by arcticio — 9 Sep 2011 @ 7:56 AM

  7. So Exxon, who already benefits through unabated fossil fuel sales bought by continued FUD from contrarians, has another reason to buy some more FUD from contrarians in order to shrink the Arctic sea ice cover some more and increase its profits from the Arctic Rosneft deal.

    Sounds like a good time to enter the professional contrarian business… Does anyone know of an Exxon contact who I can send my CV to get a FUD grant?

    Comment by cynicus — 9 Sep 2011 @ 7:58 AM

  8. Didn’t Connolley (et al?) also do a paper on modelled recovery of sea ice after artificial ice-free events? I remember thinking when Tietsche et al came out that it looked like a retread.

    Comment by Nick Barnes — 9 Sep 2011 @ 8:31 AM

  9. Given the continuous and quickening ice volume decrease it looks like the ice is unstable in _present_ conditions. In other words, in present climate conditions a late summer ice pack cannot exist, nor recover from artificial removal.

    In fact, no realistic emission reduction scenario is going to prevent us from witnessing a first ice free Arctic summer before the year 2020.

    Comment by cRR Kampen — 9 Sep 2011 @ 8:50 AM

  10. The Uni Bremen sea ice extent index reached an historical low point on September 8, about 26,000 km2 below its 2007 minimum (and probably will decline further).

    http://neven1.typepad.com/blog/2011/09/historical-minimum-in-sea-ice-extent.html

    http://www.uni-bremen.de/universitaet/presseinfos/pressemitteilungen/einzelanzeige/article/meereisflaechen-in-der-arktis-so-klein-wie-nie.html?cHash=b495f16c62179005d56ac912598830f5

    Comment by L Hamilton — 9 Sep 2011 @ 9:12 AM

  11. IMPORTANT NEWS REPORT

    Southern California has experienced a massive Schwarzenfeld beginning at 3:30 PM Thursday, Sept. 9, 2011 and ending 2:00 AM Friday.

    A Schwarzenfeld is a massive negawatt event caused by a perfect storm of Greenwashing led by a Governor and an Energy Commission.

    A negawatt event is when power produced is reduced. For those capable of subtracting, it is what happens when something stops and you subtract the output that is thus ended.

    During the time of the Schwarzenfeld the developed world in Southern California, from Arizona to the Sea and from Orange County into Mexico, reverted to an ancient, primitive condition. At first the phenomenon exhibited as general paralysis of society as demonstrated by traffic grid-lock and disablement of all civilized mechanisms for food preparation leaving hapless folk with only that which could be done by means of that ancient device known as fire. This deteriorated further into a condition known as darkness with some modification from candlelight. The sense of doom was then lifted and a measure of hope for the future returned to the dismayed peoples with observations of a round thing in the sky, hitherto obscured by city lights, known as a moon.

    A spokesman for the local SDGE has repeatedly explained that the problem was due to an ‘event’ in Arizona which was aggravated by inadequate transmission lines. He seemed not aware of the effect of the State of California having banned coal as a fuel for making electricity, thus removing the backbone power source that could once have been depended on to keep the electric grid system provided with energy.

    Comment by Jim Bullis, Miastrada Company — 9 Sep 2011 @ 10:05 AM

  12. Some of us have done back-of-the-envelope calculations (i.e. amateurishly simple and wrong) calculations of the effects of albedo loss in terms of terawatts of power being dissipated in summertime Arctic waters that otherwise would have been reflected back into space. For many of us (me) it’s helpful to our intuitions to be able to think of these matters in terms of 100W lightbulbs, familiar sizes of electric motors or whatever; many of us can relate to KWH thanks to paying electrical utility bills.

    I vaguely remember getting a figure of something like 80TW on a given June midday, using the average loss of albedo for the past 10 years. That might be way off; the amount of power and zeros here is way beyond what fits comfortably between my ears. Is this number remotely correct?

    Comment by Doug Bostrom — 9 Sep 2011 @ 10:34 AM

  13. Could a new wind driven ocean current caused by the loss of ice cover import warmer water into the Arctic Ocean? Is this a reasonable possibility?

    Comment by Andy — 9 Sep 2011 @ 11:07 AM

  14. I just read through the Tietsche paper, and don’t see where they get “Much of this ice then survives the following summer, and sea-ice conditions can quickly return to those before the artificial perturbation.” It’s a pretty thin paper and I don’t see on what this is based. Must be the models, but what parameters determine that most of the thin new ice survives the next melt season, if the previous was warm enough to melt older thicker ice?

    Comment by Jathanon — 9 Sep 2011 @ 11:36 AM

  15. A bit off the main topic: I’d like to congratulate whoever came up with Figure 2 for an excellent, innovative and informative presentation of quantitative information.

    Comment by Michael Tobis — 9 Sep 2011 @ 11:47 AM

  16. Good article. But it will not persuade those who choose to believe otherwise, such as Gov Perry.

    Comment by john burgeson — 9 Sep 2011 @ 11:48 AM

  17. Does the break up of thin ice by wave action affect albedo much?

    Is ice quality changing like David Barber has said (http://video.hint.no/mmt201v10/osc/?vid=55)?

    Did the models used by Tietsche et al. take account of these factors? If not, should they have?

    P.S.How fast is the thickness of ice actually falling?

    Comment by Geoff Beacon — 9 Sep 2011 @ 11:52 AM

  18. I’ve thought about this a (very) little further. What their models seem to say, is that even if the arctic basin contained only thin fresh new ice at the beginning of the melt season, most (or “much”) would not melt out during the summer. Even several decades from now.
    Is this an assumption, or does it stand up to scrutiny?

    Comment by Jathanon — 9 Sep 2011 @ 1:15 PM

  19. I’ve always thought this work is largely irrelevant in any practical sense. I’m sure the science is fine, but it doesn’t really tell us anything we didn’t already know. Intuitively, it is clear that a series of cool years would result in a return of sea ice. But what is equally intuitively obvious is that subsequent warm conditions will result in more melt. Figure three confirms this.

    The important point from this paper is that the ice only recovers back to the level of the GCM model and continues the decline within that scenario. I.e., so long as there is more energy coming in than going out, a few cool summers don’t mean diddly squat because the overall climate trend rules.

    Yes, this might help slow the overall decline and some technocopians might think we will then find the magic answer to all this that allows us to continue to consume the resources of the planet unabated, but at the end of the day, more energy equals less ice.

    If we reverse the GHG trend before the permafrost and clathrates let loose, the ice will recover. But we already knew that. This does show it can recover quickly, but the variation in the record from ’79 – ’11 also shows that. And, you’ll note in Fig. 3 it doesn’t appear to slow the trend at all. This probably reflects the growing energy being stored in the oceans and that this becomes dominant over time as the oceans get closer to their max capacity to efficiently store heat.

    I don’t mean to be dismissive of the science. I know this sort of study helps refine our understanding, etc., but I think people are taking the wrong message from the work: It’s not that it can recover, it’s that it’s irrelevant if the overall problem isn’t solved.

    What would be more interesting to me would be a study that showed a series of cool years via a natural cool trend (a convergence of ENSO, PDA, insolation, etc.?) might help slow or reverse the overall climate trend significantly enough for our efforts to have a chance to succeed. But the ice seems to be a feedback, not a forcing, thus is a trailing indicator overall, which means whatever the condition of the ice, the overall situation is worse than that.

    Which is why some of us are scared for our progeny.

    Comment by ccpo — 9 Sep 2011 @ 1:36 PM

  20. Speaking as a layman, I have to say that the Tietsche, et al. paper and especially its media coverage puzzled me.

    My take on the paper is exactly what ccpo(19) said: Kick the system into a new state it will relatively quickly revert to its prior path. A useful finding based on (presumably) sound science, to be sure, but not something particularly remarkable.

    The main issue I had was with this notion that this finding proved there is no “tipping point” for Arctic ice.

    An exogenous shock to the system — e.g. little green men show up in their spaceship and steal all the Arctic ice for their intergalactic party — seems to be such a radically different scenario from the continued warming via ghg emissions that I’m not sure why the ensuing behavior says anything about “tipping points”. Perhaps this is just a function of my not being sufficiently familiar with systems science and I’m getting too hung up on a change that arises from the inner workings of the system and one that’s imposed from the outside and not caused by state or behavior of the system. I (think I) understand what the study found — that albedo flip isn’t powerful enough to override other factors in this highly unusual scenario and hold the system in the new state. But as long as we’re still warming from the current disequilibrium and we continue to push atmospheric co2 to ever higher levels, it seems like a hollow victory.

    Oh, and ditto what Michael Tobis said about Figure 2. Excellent piece of graphsmanship.

    Comment by Lou Grinzo — 9 Sep 2011 @ 2:28 PM

  21. Dr Notz wrote:

    Another reason, however, is possibly the fact that we scientists have failed to make sufficiently clear that a major loss of sea ice during the early summer months is climatologically more important than a record minimum in September.

    Could less and less ice in September have an increasing effect on NH weather patterns? What happens when all that heat in those huge expanses of water gets released to the atmosphere? Does it affect winter weather? Because if it does, it might not be so misdirected to focus on minimum extent in September.

    And it also adds an extra dimension to the Tietsche et al paper. Sure, the ice might return and hang on for a few years after the ice pack in the Arctic Ocean melts out completely, but what will the effect be on weather patterns we depend on for agriculture?

    Comment by Neven — 9 Sep 2011 @ 2:36 PM

  22. re: ice extent and volume and albedo

    Area, not extent, would be the controlling metric. A part of the ocean is counted in the extent metric if it has at least 15% sea ice. So, an area with 86% open sea would count in the extent metric. Sunlight wouldn’t be so finicky. If the ice isn’t there, it isn’t there.

    This year has set the sea ice area minimum record.

    Comment by Jeffrey Davis — 9 Sep 2011 @ 3:32 PM

  23. Will this cause another snowmageddon this winter?
    Odds, sorry probabilities?

    Comment by Tony O'Brien — 9 Sep 2011 @ 3:59 PM

  24. 20: “An exogenous shock to the system — e.g. little green men show up in their spaceship and steal all the Arctic ice for their intergalactic party — seems to be such a radically different scenario from the continued warming via ghg emissions that I’m not sure why the ensuing behavior says anything about “tipping points”.”

    Surely it says there is no way of their being a tipping point (unless the model is missing something) because if there was a tipping point below which ice volume/extent would collapse permanently pretty much regardless of the climate situation, then you wouldn’t expect ice to bounce back so quickly, or really at all. It says that while there are some feedbacks around ice albedo and such, they aren’t big enough to lead to runaway melting, and that the ice extent/volume is more or less going to remain a function of the temperature – shown by how quickly the red lines snap back to the blue (no artifical removal) scenario.

    Comment by Stuart — 9 Sep 2011 @ 4:11 PM

  25. Today the german media outlet SPIEGEL online brought the story
    http://www.spiegel.de/wissenschaft/natur/0,1518,785356,00.html

    It was about 5 minutes on the frontpage then went quickly to the bottom of the page to make room for more pressing coverage.

    Comment by prokaryotes — 9 Sep 2011 @ 4:44 PM

  26. I’m still having a hard time comprehending this. If in 2020, the little green men scoop up all the ice, by the beginning of June 2021, there will be approximately 1.7 km^2×10^6 sea ice (see Figure 3). Currently, that amount of ice melts, oh, before the end June it looks like (http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png).
    So why would there be about 4 km^2×10^6 of sea ice beginning of June in 2022 (again, Figure 3)?

    Comment by Jathanon — 9 Sep 2011 @ 4:52 PM

  27. I just looked at this while procrastinating on a Friday afternoon — modis arctic mosaic. Have never seen such large fracturing near the North Pole, which is the upper left corner of image.
    http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r03c04.2011252.terra.500m

    And also from North Greenland to the Pole (upper right in this image). Must be some large weather forces at work.
    http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r03c03.2011252.terra

    Comment by Jathanon — 9 Sep 2011 @ 5:08 PM

  28. In IPCC climate models do not capture Arctic sea ice drift acceleration: Consequences in terms of projected sea ice thinning and decline, Rampal et al state:

    IPCC climate models underestimate the decrease of the Arctic sea ice extent. The recent Arctic sea ice decline is also characterized by a rapid thinning and by an increase of sea ice kinematics (velocities and deformation rates), with both processes being coupled through positive feedbacks. In this study we show that IPCC climate models underestimate the observed thinning trend by a factor of almost 4 on average and fail to capture the associated accelerated motion.

    It seems obvious the models understate the loss of extent. Per Rampal they understate ice thinning. Given that Tietsche’s results are dependent on the models, shouldn’t we be just a little bit wary?

    Comment by Kevin O'Neill — 9 Sep 2011 @ 6:29 PM

  29. Stuart “…while there are some feedbacks around ice albedo and such, they aren’t big enough to lead to runaway melting…”

    I’ve never been much interested in this paper. I know albedo’s important, but it’s nowhere nearly as important for ice strength/weakness, melt/freeze as ocean heat content these last 10-15 years. Every current that moves into, under or through Arctic ice now is warmer than any similar body of water was 20 years ago.

    If irretrievable melting occurs, it won’t be from albedo. It will be ocean waters transferring heating from 15000-20000 kms away 15-20 years ago. I think it can be avoided. I even believe it can be reversed if it happens. But neither is possible without substantially reducing CO2 concentrations, not just emissions.

    Comment by adelady — 9 Sep 2011 @ 6:45 PM

  30. I wish to point out that the statement of the sea-ice/ocean albedo feedback given above is incorrect. Sure, then the sea-ice is covered with fresh snow in winter, the albedo is high, but when summer rolls around and the surface begins to melt and form ponds, the albedo drops considerably, with measurements showing less than 40% as a large fraction of the area becomes covered by ponds. And, the albedo of water is high when the sun is high overhead at lower latitudes, but when the the zenith angle increases at high latitudes, the albedo of the ocean becomes large, as high as 30% or greater, depending on the zenith angle and the wind. For most of the melt season, the zenith angle is small, for example, at the North Pole, the sun never rises more than 23.5 degrees above the horizon and that happens only on one day. Just now, we are about 10 days from the time when sun drops below the horizon at the North Pole, not to return for 6 months. Ask anyone who has spent time aloft about sun glint or look at photos, such as those taken from the Shuttle.

    Want proof? Look at these photographs taken during the SHEBA experiment.

    http://i454.photobucket.com/albums/qq268/Know_body/ice_jul24.jpg

    http://i454.photobucket.com/albums/qq268/Know_body/ice1.jpg

    The confusion may be the result of the frequent use of satellite photographs to present images of the sea-ice. Those photos are taken from directly overhead and do not capture the sun glint, which is reflected in a cone about the same zenith angle as the angle of incidence. Thus, the energy contained in this narrow cone is never measured. Also, the water appears very dark, because the incident light returned from the surface is that which arrives from nearly overhead and most of that is absorbed. The second photo above does capture the intensity of the reflected energy, as the camera lens is closed considerably with the effect that the floating sea-ice appears quite dark, nearly as dark as the water.

    The referenced paper by Tietsche et al. needs to be carefully examined to determine just how accurately their model represents the physics. We really need to get with the program here and fix the models, which we know tend to understate the rate of decline in area which has been observed in the satellite record of extent.

    Comment by Eric Swanson — 9 Sep 2011 @ 7:27 PM

  31. Don’t forget, when the lights go out every winter, the ice ALWAYS comes back to the poles. Even in 2080, the ice will come back every winter, although it will be thin.

    The poles are the Earth’s “radiators”. In winter when there is no sunlight at the poles for months on end, the only energy source into the region is the energy barreling up from the tropics and temperate regions via winds and ocean currents, which radiates into space as fast as it possibly can in the polar darkness. Daily temperature where you live falls rapidly when the sun goes down, and if the sun did not rise the next day, temperatures would continue to fall rapidly, but in polar winter the sun DOESN’T come up the next day, and so the sea and the atmosphere cool as fast as the incoming radiation from lower latitudes (yes, and ‘sensible heat’ from the ocean) will permit. Also, evaporative cooling of the ocean surface is very efficient once its radiant energy source is removed. (I recall that more than 90% of absorbed solar radiation is released back to the atmosphere through evaporation very quickly during the daily cycle. Or do I recall that wrongly?)

    That is why the ice always recovers to its climatic equilibrium in a few years in the model results above – lack of sunlight in winter leads to dramatic seasonal cooling with rapid recovery of the ice AND a restoration of the ice albedo effect.

    The reason that this equilibrium continues to fall through 2080 is the relentless rise of greenhouse gases. In the humid tropics, water vapor is the dominant GHG, and increasing CO2 has a relatively small effect, but at the poles in winter when it is bitterly cold, there are many orders of magnitude less water vapor, giving CO2 and other GHGs a substantial role in controlling radiant energy losses. Therefore a jump in CO2 has a big effect in slowing winter cooling at the poles, allowing the high latitude energy balance to warm to the point that there is only seasonal ice, no permanent ice.

    Comment by Jbar — 9 Sep 2011 @ 7:41 PM

  32. Thanks Eli Rabett @ 3,
    I wasn’t aware of Roger Pielke Sr. or his “insistence that global temperature series is an inferior metric to ocean heat content”, but I’ve held a similar opinion for some time. Looking him up I now realise he is a sceptic (I’m being polite).

    The upper ocean is largely where “the climate” accumulates and redistributes heat. It is what determines the kinetics of climate change (AGW). And yes, we’ve only recently started getting a handle on measuring OHC with any precision.

    That said, Pielke is obsessed with an apparent short-term pause in a long term rising trend. Like many denialists (yes he is a sceptic) he tries to make a lot out of statistical variability that favours his argument.

    RC and other sites have dealt with his case far better than I can:
    http://www.realclimate.org/index.php/archives/2010/05/ocean-heat-content-increases-update/
    http://www.realclimate.org/index.php/archives/2009/07/more-bubkes/
    http://www.realclimate.org/index.php/archives/2011/07/revisiting-historical-ocean-surface-temperatures/
    http://www.realclimate.org/index.php/archives/2006/03/pielke-pere-et-fils-in-nature/
    http://www.skepticalscience.com/cooling-oceans-basic.htm
    http://www.skepticalscience.com/cooling-oceans-intermediate.htm

    Comment by Bruce Tabor — 9 Sep 2011 @ 8:25 PM

  33. Whew! I’m glad that the sea ice can recover and I hope that that is correct. The bad news is BAU = sea ice gone by 2060, if anybody is still here to notice.

    The figures are great and the article is easy to understand [good].

    The problem remains shutting off the fossil fuel burning.

    21 Neven: “what will the effect be on weather patterns we depend on for agriculture?”
    We already know the answer to that from Bart Levenson: We starve in the early 2050s. Population and civilization crash.

    “Does it affect winter weather?” It gets cold in the wrong places again.

    22 Tony O’Brien: Look up Rossby waves. Where it is cold and where it is less cold rotate by 45 degrees longitude. “Snowmageddon” it is in the wrong places. Get used to the new norm. But you didn’t really get much snow due to GW that has already happened. Like when Rochester, N/Y. got 9 feet [108 inches] in 1 day circa 1966. Olean, N.Y. got 450 inches per year in the 1950s and now gets only 96 inches per year. It hasn’t gotten to 40 below there [straight temperature] since the 1930s.

    Comment by Edward Greisch — 9 Sep 2011 @ 10:06 PM

  34. #19 and #20. I fully agree with these comments. I believe the paper assumes that ‘artificially’ removing the ice and then the ice growing back again is not the point with respect to tipping points. The relevant issue is if some feedback that is already part of the system grows to the point where it causes much faster loss of ice. In this case, unless the feedback mechanism value can be reverted back to its original value, the sudden ice loss will indeed remain on the lower side of the tipping point. A better analogy than artificial removal of the ice and it growing back again might be the picture of a system with a cycle that follows a particular path, year on year and, due to some feedback growing to an over-riding value, enters a different cyclic path year on year. It is not going to return to the other path unless something reverses the value of the feedback mechanism. Sorry for the long post – a separate rebuttal paper might be more appropriate, but I am not a climateologist, but a mathematician.

    Comment by John — 9 Sep 2011 @ 10:44 PM

  35. This part of the results of this study is hugely important:

    “…the ice-albedo feedback mechanism is, in isolation, too weak to stabilize a very low sea-ice cover.”

    _____

    Here’s the thing…the ice-albedo feedback mechanism may exist in isolation in a targeted climate model, but never will be found in isolation in the real world, and just as all the models prior to 2007 were projecting an ice-free summer arctic by the 2100 or later, they all were quite wrong and had to be adjusted radically sooner because of course no model can predict how a system on the edge of chaos with multiple interrelated feedbacks will actually progress…i.e. none of them can predict the true tipping points, and this new model is no different. For example, the study did not take into account continued increases in ocean temperatures of water entering the Arctic (as they have been for many years), nor of course, the likely continued increases in methane in the atmosphere, at least partially being created by the same warming of those arctic waters.

    In my opinion, the most accurate way to see what the likely future of Arctic sea ice will be is to use the models only as rough guides (accepting that modelling a system on the edge of chaos will always fail to see the tipping points), and rather, to look to the Earth’s past, when similar climate dynamics existed. In this case, we are led to the mid-Pliocene at least and perhaps further back to even warmer climates. In such scenarios, multiple (and not completely understood feedbacks) create the conditions for the Arctic to be ice-free or nearly so year round, Greenland and Antarctica lose most, if not all, of their glacial ice, and the world to be a vastly different place. So, while it’s nice to look at very specific isolated models, they are more an exercise in precise and confined modelling, as opposed to creating a realistic scenario of the real climate under multiple interrelated feedbacks. Only looking at past similar climates can give us the best glimpse of what happens in the real world of a climate system on the edge of chaos.

    Comment by R. Gates — 9 Sep 2011 @ 11:33 PM

  36. @Alex Thomas
    “The ice volume change is less relevant to the ice-albedo feedback, where the relative proportions of ice covered to ice free ocean dominate the radiative effect…”

    Alex, I can only agree. A simple thought experment shows that it matters little to albedo if the ice is 1 cm or 10 metres thick.

    What does concern me though is the thermal forcing is only getting worse; that is there is little prospect of a reduction in radiative forcing (“an efficient reduction of CO2 emissions”), or a reduction in heat transfer from the local water (presumably related to ocean heat content).

    I simply don’t believe the blue line in Figure 3 above. I’ve yet to see a GCM that is skillful in predicting Arctic sea ice loss or what is happening to the cryosphere in general. I’m not a climate scientist so maybe I’m not in touch. Please correct me if necessary.

    To my eye THIS is NOT linear:
    http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.png?%3C?php%20echo%20time%28%29%20?

    That may be due to autocorrelation or a non-linear trend. Despite its limitations THIS appears more plausible:
    http://neven1.typepad.com/.a/6a0133f03a1e37970b015435378c39970c-pi
    Is there a GCM that can account for what APPEARS to be an year-round accelerating trend loss of arctic sea ice volume?

    Furthermore, I think the main point of the Tietsche paper is lost in the post above. That is, assuming their GCM is accurate, arctic ice loss does not exhibit hysteresis – it is fully and rapidly recoverable when favourable conditions return. That is, it does not constitute a “tipping point”.

    Comment by Bruce Tabor — 10 Sep 2011 @ 2:35 AM

  37. Jathanon@25: Consider, how much ice would there be at the end of March 2022?

    Jathanon@26: Check out the ice exactly one year earlier:
    http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r03c04.2010252.terra.500m

    Comment by Nick Barnes — 10 Sep 2011 @ 2:53 AM

  38. @ JBar,
    “Don’t forget, when the lights go out every winter, the ice ALWAYS comes back to the poles. Even in 2080, the ice will come back every winter, although it will be thin…”

    Well, no. If it were that simple, all regions where ocean is exposed to the polar night would form an ice cover. Not all do, as it depends on the energy balance. If, due to ocean heating and ocean currents, the water temperature remains subtantially above zero in the Arctic, an ice cap will not form even at the North Pole in mid-winter. This has been the case in the distant past.

    Comment by Bruce Tabor — 10 Sep 2011 @ 5:30 AM

  39. http://www.agu.org/journals/gl/gl1117/2011GL048681/2011gl048681-op01-tn-350x.jpg
    Sea ice loss enhances wave action at the Arctic coast

    Overeem, I., R. S. Anderson, C. W. Wobus, G. D. Clow, F. E. Urban, and N. Matell
    Geophys. Res. Lett., 38, L17503, doi:10.1029/2011GL048681
    9 September 2011

    Comment by Hank Roberts — 10 Sep 2011 @ 5:49 AM

  40. Bruce, @ 38–good points. Don’t some think that during the Paleocene-Eocene Thermal Max the Arctic remained ice free year round?

    http://www.nature.com/nature/journal/v441/n7093/abs/nature04668.html
    http://geology.gsapubs.org/content/37/6/499.abstract

    How much of a role do you think increased water vapor had in sustaining these temperatures throughout the year?

    Comment by wili — 10 Sep 2011 @ 8:00 AM

  41. Bruce@38: the great majority of ocean exposed to polar night does indeed form an ice cover. The main exception north of 70N is areas of the Greenland and Barents Seas, where warm surface waters from the Atlantic can (in some years) prevent freezing. But in the Arctic Ocean proper, everything freezes. Even waters which have melted early in the season and thus been exposed to continuous solar heating for months still freeze over. Look at the winter of 2007/2008. The Arctic Ocean needs to get a *lot* warmer before this is prevented.

    Comment by Nick Barnes — 10 Sep 2011 @ 8:11 AM

  42. Re #30:
    A minor correction, the angle of the sun above the horizon is the solar elevation angle, the solar zenith angle is the angle measured from nadir to the sun.

    Not sure why you think sun glint is important. Glint occurs with a more or less unique but transient alignment of solar zenith and solar azimuth, wind and wave direction relative to the solar angles, and, finally, the viewing angle of the sensor relative to the sun and the waves. Few visual wavelength satellites sensors “see” above about 82 N (northern edge of Greenland) or 82 S.

    Comment by BillS — 10 Sep 2011 @ 8:53 AM

  43. Well, that’s a shock.

    http://neven1.typepad.com/blog/2011/09/historical-minimum-in-sea-ice-extent.html

    Comment by Jeffrey Davis — 10 Sep 2011 @ 9:29 AM

  44. Re #13 Andy and #31 JBar
    Regarding radiators and wind — I see the minimum area as quite an important factor. I used to harp on about June ice coverage as being the most significant thing to watch and report on, rather than the September minimum. But the blogs taught me better and the Tietsche et al Fig 3 is instructive. How can we turn this to our advantage?

    Well, maybe we can use wind to upgrade the radiator … in winter. What if ice area can be reduced, to decrease the winter insulation and increase heat loss from the Arctic Ocean to the long night? Instead of Figure 3 above (in which sea ice is disappeared in June), what if sea ice can be disappeared (or compressed) in winter — every year? Can we lose enough energy to space to slow the warming of the planet?

    Comment by Steve L — 10 Sep 2011 @ 11:07 AM

  45. Fellow commenters, Read The Paper. Then read it again for comprehension.

    [Again the top post does not have the correct link for humans. The correct link is
    http://www.seas.harvard.edu/climate/seminars/pdfs/Tietsche_GRL_2011.pdf
    ]

    “Didn’t Connolley (et al?) also do a paper ….?”
    first page:

    Schröder and Connolley [2007], who showed that sea ice
    recovers from a complete removal within a few years.
    However, they restricted their experiments to a preindustrial
    climate and did not address the mechanisms of the sea-ice
    recovery.

    “I just read through the Tietsche paper, and don’t see where they get “Much of this ice then survives the following summer, and sea-ice conditions can quickly return to those before the artificial perturbation.””

    It plainly says the paper shows model based calculations. Of course you don’t see all the equations written in computer code unless you study the model separately.

    “I’ve always thought this work is largely irrelevant in any practical sense. I’m sure the science is fine, but it doesn’t really tell us anything we didn’t already know. Intuitively, it is clear that a series of cool years would result in a return of sea ice.”

    1)The reason scientists do research is that “intuitively clear” might leave you in ignorance of Newton’s laws for thousands of years.
    2) The paper is not about removal of sea ice followed by a cooler climate. It is about continuing nearly the same climate, just without, say, the unusual Arctic weather of 2007.

    “The referenced paper by Tietsche et al. needs to be carefully examined to determine just how accurately their model represents the physics.”

    Not a chance. The paper says on page 1

    Here, we report the recovery of the Arctic from
    a prescribed loss of summer sea ice in the AOGCM
    ECHAM5/MPI-OM at different times ….

    You may study the physics of this standard model separately if you wish, but first I recommend understanding the paper as such.

    Enough of comments. What of the paper? From page 1 again:

    A valuable tool for understanding those mechanisms
    are experiments which perturb Arctic sea!ice conditions
    systematically. To our knowledge, this sea!ice perturbation
    approach in an AOGCM has so far only been applied by
    Schröder and Connolley [2007], who showed that sea ice
    recovers from a complete removal within a few years.
    However, they restricted their experiments to a preindustrial
    climate and did not address the mechanisms of the sea-ice
    recovery.

    Here, we report the recovery of the Arctic from
    a prescribed loss of summer sea ice in the AOGCM
    ECHAM5/MPI-OM different times during the 21st century,
    and investigate the mechanisms of recovery by analyzing the
    Arctic energy budget. In these perturbation experiments, the
    initial conditions are such that the ice–albedo feedback, as well
    as the other feedbacks related to sea-ice anomalies, are most
    pronounced. Thus, these experiments answer the question of
    whether perturbations of sea-ice cover alone are able to trigger

    I submit that this type of perturbation experiment (be thankful it is done within a model, not in vivo) is very worthwhile.

    Meanwhile what of the Arctic? Arctic amplification of global warming is occurring at the pace of the US Navy’s Arctic regional model, which is to say quite a bit faster than in the global models. The Arctic is changing quickly enough so that the climate which the sea ice would recover to in three years is warmer than the climate of the sea ice removal in year one of the model runs. Thus in practice so far, recovery is to a lower quantity of ice. The reductions in ice volume, area and extent so far indicate that we will reach the point that the weather of 2007 is not needed to clear the ice in September sooner than the global models predict. It would be interesting to run the model experiment in the Naval model.

    Comment by Pete Dunkelberg — 10 Sep 2011 @ 12:54 PM

  46. Nick Barnes says:
    10 Sep 2011 at 2:53 AM
    Jathanon@25: Consider, how much ice would there be at the end of March 2022?

    There would be more than the June 1, 2022 point of course. How much their model has at time we don’t know. However, consider that
    1. No ice on June 1, 2020
    2. Ice grows again during winter 2020-21
    3. Ice is at 1.7 on June 1, 2021
    4. Ice melts out maybe by July 1, 2021
    5. Ice grows again during winter 2021-22
    Now, why would considerably more ice grow this winter, starting from a no ice condition in mid-summer? When “large amounts of heat indeed accumulate in the ocean during the ice-free summer. However, this heat is efficiently released to the cold atmosphere already during the following autumn and winter.”
    To me, it sounds like after removal, every following year would have around 1.7, melting out and starting over.

    Comment by Jathanon — 10 Sep 2011 @ 1:07 PM

  47. Fellow commenters, Read The Paper. Then read it again for comprehension.

    [Again the top post does not have the correct link for humans. The correct link is
    http://www.seas.harvard.edu/climate/seminars/pdfs/Tietsche_GRL_2011.pdf
    ]

    “Didn’t Connolley (et al?) also do a paper ….?”
    first page:

    Schröder and Connolley [2007], who showed that sea ice
    recovers from a complete removal within a few years.
    However, they restricted their experiments to a preindustrial
    climate and did not address the mechanisms of the sea-ice
    recovery.

    “I just read through the Tietsche paper, and don’t see where they get “Much of this ice then survives the following summer, and sea-ice conditions can quickly return to those before the artificial perturbation.””

    It plainly says the paper shows model based calculations. Of course you don’t see all the equations written in computer code unless you study model separately.

    “I’ve always thought this work is largely irrelevant in any practical sense. I’m sure the science is fine, but it doesn’t really tell us anything we didn’t already know. Intuitively, it is clear that a series of cool years would result in a return of sea ice.”

    1)The reason scientists do research is that “intuitively clear” might leave you in ignorance of Newton’s laws for thousands of years.
    2) The paper is not about removal of sea ice followed by a cooler climate. It is about continuing nearly the same climate, just without, say, the unusual Arctic weather of 2007.

    “The referenced paper by Tietsche et al. needs to be carefully examined to determine just how accurately their model represents the physics.”

    Not a chance. The paper says

    Here, we report the recovery of the Arctic from
    a prescribed loss of summer sea ice in the AOGCM
    ECHAM5/MPI-OM at different times

    You may study that standard model separately if you wish, but first I recommend understanding the paper as such.

    Enough of comments. What of the paper? From page 1 again:

    A valuable tool for understanding those mechanisms
    are experiments which perturb Arctic sea-ice conditions
    systematically. To our knowledge, this sea-ice perturbation
    approach in an AOGCM has so far only been applied by
    Schröder and Connolley [2007], who showed that sea ice
    recovers from a complete removal within a few years.
    However, they restricted their experiments to a preindustrial
    climate and did not address the mechanisms of the sea-ice
    recovery.

    Here, we report the recovery of the Arctic from
    a prescribed loss of summer sea ice in the AOGCM
    ECHAM5/MPI-OM different times during the 21st century,
    and investigate the mechanisms of recovery by analyzing the
    Arctic energy budget. In these perturbation experiments, the
    initial conditions are such that the ice–albedo feedback, as well
    as the other feedbacks related to sea-ice anomalies, are most
    pronounced. Thus, these experiments answer the question of
    whether perturbations of sea-ice cover alone are able to trigger

    I submit that this type of perturbation experiment (be thankful it is done within a model, not in vivo) is very worthwhile.

    Meanwhile what of the Arctic? Arctic amplification of global warming is occurring at the pace of the US Navy’s Arctic regional model, which is to say quite a bit faster than in the global models. The Arctic is changing quickly enough so that the climate which the sea ice would recover to in three years is warmer than the climate of the sea ice removal in year one of the model runs. Thus in practice so far, recovery is to a lower quantity of ice. The reductions in ice volume, area and extent so far indicate that we will reach the point that the weather of 2007 is not needed to clear the ice in September sooner than the global models predict. It would be interesting to run the model experiment in the Naval model.

    Comment by Pete Dunkelberg — 10 Sep 2011 @ 1:17 PM

  48. RE # 42, BillS mentions the difference between solar elevation and zenith angle. At the North Pole, the elevation never exceeds 23.5, thus the zenith angle never falls below (90 – 23.5) = 66.5 degrees. The reason sun glint is important is that water, like any transparent media, becomes highly reflective as the angle of incidence (aka, the zenith angle) approaches 90 degrees. On clear days, much of the energy arrives in the direct beam and much of that will tend to be reflected from the water’s surface. The effect is also a function of wave height and wave height is a function of wind speed (mol) for the open ocean. On cloudy days, the clouds scatter the light and thus the albedo may be higher, but the clouds also reflect some fraction of the light back to space, so the net energy entering the ocean may not be so great. Here’s a graph of ocean albedo taken from a report by Payne, written in 1972, in which the author presented data from measurements taken from an old platform in the ocean:

    http://i454.photobucket.com/albums/qq268/Know_body/Figure5.jpg

    It’s worth mentioning that the satellite sensors used to measure radiant energy over the poles can not directly view the energy in the sun glint because of the angles involved. For example, the present AQUA and TERRA satellites do not cover the Arctic at times of the day when any sun glint is likely to be within view of the sensors. Your reference to an 82 degree limit applies to the ground track, but instruments such as CERES scan cross track to cover higher latitudes as the ground track turns briefly east-west.

    TERRA has an equator crossing at 10:30 AM local time, but the highest latitude is crossed 6 hours earlier in local time at 4:30 AM. The AQUA orbit equatorial crossing is at 1:30 PM local time, the highest latitude time is 6 hours earlier at 8:30 AM, AIUI. One can look at various orbit track times for both satellites here, to add to the confusion:

    http://nsidc.org/data/modis/terra_aqua_differences/index.html

    Comment by Eric Swanson — 10 Sep 2011 @ 1:47 PM

  49. It’s unfortunate Dirk Notz doesn’t have the time to answer some of the interesting questions in the comment section.

    Comment by Neven — 10 Sep 2011 @ 4:24 PM

  50. 5 Alex says, “The ice volume change is less relevant to the ice-albedo feedback, where the relative proportions of ice covered to ice free ocean dominate the radiative effect. Reducing ice thickness (volume) will serve to make the system more sensitive to melting (and further area loss and radiative feedback) but as mentioned in the Tietsche et al paper this will be rapidly recovered from.”

    You fail to understand that volume is incredibly important to the date of ice loss for the next year. Thin ice melts out earlier, and since the albedo effect is most important early in the summer, thinning of ice becomes quite important to feedbacks.

    Comment by RichardC — 10 Sep 2011 @ 8:34 PM

  51. @ JBar,
    they found alligator sceletons near the north pole.

    Fossil animals found in Arctic Canada (Nunavut Territory) provide a snapshot of fish evolving into land animals, scientists say. The 383 million-year-old specimens are described as crocodile-like animals with fins instead of limbs that probably lived in shallow water.

    Crocodile-like

    The creature shares some characteristics with a fish; it has fins with webbing, and scales on its back. But it also has many features in common with land animals. It has a flat crocodile-like head with eyes positioned on top and the beginnings of a neck – something not seen in fish.

    “When we look inside the fin, we see a shoulder, we see an elbow, and we see an early version of a wrist, which is very similar to that of all animals that also walk on land,” said Professor Shubin. The scientists think the creature lived in the shallows “Essentially we have an animal that is built to support itself on the ground.”

    The scientists believe the position of the creature’s eyes suggest it probably lived in shallow water. “We are capturing a very significant transition at a key moment of time. What is significant about the animal is that it is a fossil that blurs the distinction between two forms of life – between an animal that lives in water and an animal that lives on land.” http://news.bbc.co.uk/2/hi/4879672.stm

    And here is a more recent discussion, related:

    Patrick, much as we might gasp at the implications, a seasonally sea-ice free Arctic Ocean is NOT a stable climate regime. Numerical Modeling and Paleoclimate Studies indicate that there are two stable regimes for the Arctic Ocean in a warming Climate: perpetually ice-covered, and perpetually ice-free.

    These modelling result were published by Eisenman and Wettlaufer (2008) “Nonlinear threshold behavior during the loss of Arctic sea ice”. The paper (and it’s SI Appendix), is freely available from the Journal Proceedings of the National Academy of Sciences.

    Figure 3 Bifurcation diagram for the full nonlinear model

    The description of “Fig. 3″ says in part:
    “Under a moderate warming (ΔF0 = 15 Wm−2), modeled sea-ice thickness varies seasonally between 0.9 and 2.2 m. Further warming (ΔF0 = 20 Wm−2) causes the September ice cover to disappear, and the system undergoes a smooth transition to seasonally ice-free conditions. When the model is further warmed (ΔF0 = 23 Wm−2), a saddle-node bifurcation occurs, and the wintertime sea ice cover abruptly disappears in an irreversible process.”

    Above, “ΔF0 = 15 Wm−2″ should be read as “Change in Climate Forcings relative to Time Zero” in Units of Watts per square meter. This means that after the first Sea ice free September, Climate forcings need to increase by only 3 watts per square meter until the Arctic Sea Ice disappears permanently, and irreversibly. Methane Clathrates alone have the potential to increase Climate forcing by 5 W/m^2, in addition to our continued release of C02.

    Recent Paleoclimate studies show the Arctic had a perennially sea ice free ocean, an mean annual temperature over 12C, and fossilized Crocodile skeletons found on Baffin Island, the place where many current Commenters speculate will be the last stand for Arctic Sea Ice. http://www.science20.com/comments/70161/new_stable_regime_one

    Comment by prokaryotes — 10 Sep 2011 @ 10:29 PM

  52. Eric your comment only applies to one polarization that’s why Polaroid sunglasses are so useful!
    Google Brewster angle.

    Comment by Phil. — 10 Sep 2011 @ 10:52 PM

  53. prokaryotes #51 – the Canadian Arctic 350 mya, as part of Pangaea, is usually depicted on maps as being relatively close to the equator. So finding fossils in Canada of animals that lived in tropical climates should not be surprising.

    Comment by Kevin O'Neill — 10 Sep 2011 @ 11:34 PM

  54. Prokaryotes, 383 million years ago, what was the latitude of the location where the croc fossiles were found? I would think that landmasses have changed and moved quite a bit since then. What was the whole Earth climate like back then? Any best guess on what kind of CO2 concentrations were present? Context helps.

    Comment by Philippe Chantreau — 11 Sep 2011 @ 2:23 AM

  55. Jathanon@46:

    1. No ice on June 1, 2020
    2. Ice grows again during winter 2020-21
    3. Ice is at 1.7 on June 1, 2021
    4. Ice melts out maybe by July 1, 2021
    5. Ice grows again during winter 2021-22

    Where do you get this? From reading the paper, what they do is remove all the ice on July 1, 2020 (not June). In September 2020 there is no ice. In September 2021 there is about 1.7 Mkm^2 of ice. In September 2022 there is about 4 Mkm^2. I’m reading those numbers from figure 1, which only has numbers for September. Where are you getting your numbers for June 1 2021 and July 1 2021? I see no such numbers in the paper.

    Comment by Nick Barnes — 11 Sep 2011 @ 3:28 AM

  56. Hi Prokaryotes,

    Due to continental drift, a fossile 373 million years old I would not expect to have died even close to the north pole. But there is evidence that the arctic was free of ice most of the time

    Cheers,
    Marcus

    Comment by Marcus — 11 Sep 2011 @ 3:57 AM

  57. @Bruce 38
    Agreed, as evidenced by the area north of Scandinavia staying ice-free all winter, but even in 2080 ocean currents should not be warm enough to keep the whole arctic region ice free all winter (although the winter maximum extent should be reduced from today’s 13mm km2 area to perhaps 9-10mm km2).

    Comment by Jbar — 11 Sep 2011 @ 7:36 AM

  58. @Steve 44
    “Well, maybe we can use wind to upgrade the radiator … in winter. What if ice area can be reduced, to decrease the winter insulation and increase heat loss from the Arctic Ocean to the long night? Instead of Figure 3 above (in which sea ice is disappeared in June), what if sea ice can be disappeared (or compressed) in winter — every year? Can we lose enough energy to space to slow the warming of the planet?”

    The way to increase radiant energy loss to space is to increase polar/surface temperature or to reduce the radiant transfer resistance (less GHGs). Unfortunately increasing the temperature increases water vapor (a GHG) which increases the resistance in a non-linear(?) feedback. (Perhaps the increase in water vapor from very low levels with increasing temperature is a big reason why the poles warm faster than warmer latitudes?)

    I don’t know how we could practically or economically increase ocean and air currents (energy transfer) toward the arctic to warm it. It might also measurably increase GHG rate of change (fossil fuels to provide the energy to do it).

    I guess if you remove ice, the ocean surface is not much less than a few degrees below 0C rather than as low as -80C for the ice surface, so removing the ice should very sharply increase radiant losses, but once the ocean reaches 0C, the ice will reform very quickly and want to go down to minus 60-80C again. It is a monumental Sisyphean chore. Again, how could we practically or economically do that? Fleet of ships to push the ice south where it can melt?

    Seems like a possibility worth exploring some more? Anyone?

    Comment by Jbar — 11 Sep 2011 @ 8:16 AM

  59. @prokaryotes 51
    Wow – I MUST look up that paper. Dramatic conclusion. “Actual” (er, modeling) evidence for a bona fide tipping point (for year round arctic sea ice) not much beyond the total loss of summer sea ice! I’ll bet you can be sure that when arctic ice is gone year round it’s curtains for the Greenland ice cap and hello 10-20m sea level rise (Greenland + destabilized West Antarctic)!

    WRT fossil alligators in arctic, wasn’t this around the Paleocene/Eocene Climate Optimum (circa -50MM years) ? Two factors –
    1) much higher atmospheric CO2 than today.
    2) If there was a south polar land mass at that time, it must not have had a circumpolar current to act as an energy transfer barrier from lower latitudes.

    With its isolating circumpolar current (which came about after the disappearance of several land bridges circa -30MMa(?)), the Antarctic land mass is stuck in an icehouse condition, helping to cool the entire planet and requiring dramatically higher CO2 levels to thaw it out. I wonder if the arctic could get warm enough to have alligators again as long as there is a “permanent” southern ice cap?
    However, if there is a model that says so, we must consider the possibility.

    Comment by Jbar — 11 Sep 2011 @ 8:35 AM

  60. @ prokaryotes
    The Eisenman paper is fascinating. I’m still digesting it.

    I don’t think the ΔF0 in the paper relates to the global average forcing (now about 1.5 W/m^2), but to a local Arctic forcing, which will be greater than the global average.

    Their simulation is only one-dimensional, so in that respect is even more limited than the GCMs. It is a little hard to match with Tietsche’s paper, as by design Eisenman is assuming no “horizontal” heat transfer.

    Comment by Bruce Tabor — 11 Sep 2011 @ 8:42 AM

  61. There’s a funny typo in the paper:

    The resulting area of the Arctic Ocean is 8.4 · 10^12 m^2 sq miles.

    8,400,000,000,000 square miles!

    Comment by Jeffrey Davis — 11 Sep 2011 @ 9:23 AM

  62. It seems that during different times in earth past, different kinds of crocodiles appeared when climate change triggered evolution. I agree kind of hard to reconstruct the correct spot of the crocodile from 383 m years ago, judging from a single site. But after that, later they found other crocodile fossils too, near the pole. Would be nice if someone can link to earlier crocodile skeleton findings. Not sure but James Lovelock mentioned this too and a much earlier species, i believe.

    Comment by prokaryotes — 11 Sep 2011 @ 9:36 AM

  63. Tietsche et al point out that the loss the ice insulation effect works both ways; lets more heat in in summer and more heat out in winter. Also in winter thin ice forms very quickly.

    Recovery is not back to pre industrial, or even to today’s levels. Recovery is to the then normal.

    A very readable paper.

    Comment by Tony O'Brien — 11 Sep 2011 @ 12:35 PM

  64. Prokaryots – This animation shows the protocontinents’ evolution through the assembly and breakup of Pangaea (with the equator being held constant). Use your browser stop button to halt the process at about 383 million years or so and you will see that – what is to become the far North American continent was actually fairly close to the equator at the time:
    http://www.ucmp.berkeley.edu/geology/anim1.html

    hth arch

    Comment by arch stanton — 11 Sep 2011 @ 12:49 PM

  65. The hypothesis that the crocodile ended up at baffin island through continental drift is weak.

    August 12, 2010

    Giving new meaning to the phrase “older than dirt,” scientists have found evidence of an underground rock reservoir left over from the days when Earth was a ball of magma, a new study says.

    Rocks recently found on Canada’s Baffin Island erupted as lava from a deep rock reservoir that formed 4.5 billion years ago, when the solar system was new, the study says. The reservoir may hold the world’s oldest rock, according to the authors.

    (Related: “Oldest Rocks on Earth Discovered?” [2008].) http://news.nationalgeographic.com/news/2010/08/100812-worlds-oldest-rocks-magma-earth-nature-science/

    Baffin Island (Inuktitut: ᕿᑭᖅᑖᓗᒃ, Qikiqtaaluk, French: Île de Baffin, Old Norse: Helluland) in the Canadian territory of Nunavut is the largest member of the Canadian Arctic Archipelago. It is the largest island in Canada and the fifth largest island in the world,
    http://en.wikipedia.org/wiki/Baffin_Island

    There is also a small island called Alligator island. http://en.wikipedia.org/wiki/Alligator_Island

    Comment by prokaryotes — 11 Sep 2011 @ 1:42 PM

  66. How Tortoises and Alligators Survived on Ellesmere Island 50 Million Years Ago

    A new study of the High Arctic climate roughly 50 million years ago led by the University of Colorado at Boulder helps to explain how ancient alligators and giant tortoises were able to thrive on Ellesmere Island well above the Arctic Circle, even as they endured six months of darkness each year.

    The new study, which looked at temperatures during the early Eocene period 52 to 53 million years ago, also has implications for the impacts of future climate change as Arctic temperatures continue to rise, said University of Colorado at Boulder Associate Professor Jaelyn Eberle of the department of geological sciences, lead author of the study.
    Biogenic Apatite from Bones and Tooth Enamel

    The bone and tooth enamel of vertebrate fossils contains biogenic apatite — a mineral that is fossilized after the death of living organisms and which can be used as a “flight recorder” to infer paleoclimate conditions. Since all of the fossil materials were from the same stratigraphic layer and locality, the oxygen isotope ratios from the animals are linked to the temperatures of both ingested river water and precipitation at the time, allowing them to better estimate temperatures in the Eocene both annually and seasonally, she said.

    “We use the water that the animals were drinking as a proxy for paleotemperature,” said Eberle. “In mammal fossils, for example, we can analyze the oxygen isotope ratios in a sequence along the length of a large fossil tooth and estimate the warm-month and cold-month averages during the Eocene because teeth grow year round. When it comes to oxygen isotope values in tooth enamel, what we found for these creatures is that you are what you drink,” she said.

    The team looked at teeth from a large, hippo-like mammal known as Coryphodon, as well as bones from bowfin fish and shells and bones from aquatic turtles from the Emydidae family, the largest and most diverse family of contemporary pond turtles. While Coryphodon and bowfins grew throughout the year, the turtles exhibited shell growth only during summer months, much like turtles that live today in non-equatorial areas.

    Eberle said the new study implies Eocene alligators could withstand slightly cooler winters than their present-day counterparts, although data from captive alligators show they are heartier than other members of the crocodilian family and can survive short intervals of subfreezing temperatures by submerging themselves in the water.

    In contrast, the existence of large land tortoises in the Eocene High Arctic is still somewhat puzzling, said Eberle, since today’s large tortoises inhabit places like the Galapagos Islands where the cold-month average temperature is about 50 degrees F (10 degrees C.) http://geology.com/press-release/tortoises-alligators-on-ellesmere/

    Comment by prokaryotes — 11 Sep 2011 @ 1:49 PM

  67. Dramatic interannual changes of perennial Arctic sea ice linked
    to abnormal summer storm activity

    James A. Screen,1 Ian Simmonds,1 and Kevin Keay1
    Received 24 February 2011; revised 4 April 2011; accepted 4 May 2011; published 4 August 2011.
    [1] The perennial (September) Arctic sea ice cover exhibits large interannual variability, with changes of over a million square kilometers from one year to the next. Here we explore the role of changes in Arctic cyclone activity, and related factors, in driving these pronounced year‐to‐year changes in perennial sea ice cover. Strong relationships are revealed between the September sea ice changes and the number of cyclones in the preceding late spring and early summer. In particular, fewer cyclones over the central Arctic Ocean during the months of May, June, and July appear to favor a low sea ice area at the end of the melt season. Years with large losses of sea ice are characterized by abnormal cyclone distributions and tracks: they lack the normal maximum in cyclone activity over the central Arctic Ocean, and cyclones that track from Eurasia into the central Arctic are largely absent. Fewer storms are associated with above‐average mean sea level pressure, strengthened anticyclonic winds, an intensification of the transpolar drift stream, and reduced cloud cover, all of which favor ice melt. It is also shown that a strengthening of the central Arctic cyclone maximum helps preserve the ice cover, although the association is weaker than that between low cyclone activity and reduced sea ice. The results suggest that changes in cyclone occurrence during late spring and early summer have preconditioning effects on the sea ice cover and exert a strong influence on the amount of sea ice that survives the melt season. ftp://ftp.astr.ucl.ac.be/publi/2011_08_08-07h54-francois.massonnet-3.pdf

    Impacts of a recent storm surge on an Arctic delta ecosystem examined in the context of the last millennium http://www.pnas.org/content/108/22/8960.short

    Climate change projections and stratosphere–troposphere interaction http://www.springerlink.com/content/e5w4634h16272058/

    Comment by prokaryotes — 11 Sep 2011 @ 2:58 PM

  68. Prokaryotes claims that evidence is weak that alligators lived in what was to become far North America when it was much closer to the equator 385 MILLION years ago. To back up this claim a study is cited concerning 4.5 BILLION years ago that makes no claim as to the latitude of the geology in question at either the time in question or 4.5 billion years ago.

    Prokaryotes then attempts to move the goal posts by citing a publication that misleadingly uses the term “alligator” in it’s headlines when the term “alligator” is never used in the paper itself. The paper does use the term “emydid turtle” however which are known to be found well out of equatorial regions and unlike the alligator, can currently be found in much of North America (perhaps not Elsmere island) and to HIBERNATE.

    One of the authors of the paper extrapolates about how Eocene alligators may have withstood colder temperatures that today’s alligators but NOWHERE in the article OR the paper does it mention that Eocene alligators were found on Elsemer island.

    The topic at hand (Prokaryotes brought it up) was Paleozoic (Devonian) alligators.

    Even a eukaryote can see that the goal posts have been moved out of the stadium. (Today is one of *those* Sundays after all).

    http://www2.coloradocollege.edu/dept/GY/henry_pdfs/Eberle%20et%20al.%202010.pdf

    Comment by arch stanton — 11 Sep 2011 @ 3:27 PM

  69. The point is that there are many crocodile links.

    And that there is “evidence” – from the paper the first sentence…

    “As a deep time analog for today’s rapidly warming Arctic region, early Eocene (52–53 Ma) rock on EllesmereIsland in Canada’s High Arctic (∼ 79°N.) preserves evidence of lush swamp forests inhabited by turtles,alligators, primates, tapirs, and hippo-like Coryphodon.”

    The old rocks from the baffin area suggest, that there have been volcanoes islands from magma, which has been dated 4-5 b years old. This geographic setup is in agreement with the species at hand, low lying swamp like habitats.

    The repeated evidence through earth history of the crocodilian genus at the earth poles suggest that they not only came through continenatal drifts or through land migration. They probably migrated once and then re-inhabited the area when conditions changed.

    When crocodiles roamed the Arctic
    Four years later, Alfred Wegener put forward his theory of continental drift which, it was later realised, could explain the balmy climate: Antarctica had been warmer because it was once much closer to the equator. Even today, some schoolchildren are taught that continental drift accounts for all the evidence for a warmer Antarctica.

    However, the fossil trees Shackleton’s team discovered grew around 250 million years ago, when Antarctica was barely closer to the equator than it is today. What’s more, the continent reached its current position roughly 100 million years ago, and an ever-growing list of fossil finds date from 100 to 40 million years ago. During this time, when dinosaurs roamed the almost subtropical forests of an ice-free Antarctic, conditions on the other side of the planet were even more remarkable: the Arctic Ocean was a gigantic freshwater lake infested with crocodile-like reptiles.

    One of the earliest signs that the poles were ice-free and warm 100 million years ago was the discovery at the turn of the 20th century of fossil breadfruit trees from the Cretaceous in Greenland; today such trees are at home in places like Hawaii. Since then, even more extraordinary finds have been made.

    The most evocative image of a warm Arctic has emerged from the work of John Tarduno of the University of Rochester, New York. For more than a decade, Tarduno has been hunting for fossils on Axel Heiberg Island in the Canadian Arctic, just west of Greenland. The island was already well within the Arctic Circle 90 million years ago.

    His team has found bones and even partial skeletons of a crocodile-like creature called a champsosaur from this period. The champsosaur was a fish-eating reptile up to 2.4 metres long that probably looked much like the gharials of India. Because these reptiles would have relied on their environment to stay warm, conditions in the far north must have been far hotter than today. “These fossils speak volumes,” says palaeoclimatologist Paul Wilson of the University of Southampton in the UK.

    Last year, Tarduno’s team reported that most champsosaur remains are of juveniles, meaning the animals not only lived but bred in the Arctic. As hatchlings and juveniles could not have survived if winter temperatures came anywhere close to freezing, this means it was not only warm, but warm all year round.

    Modern crocodiles are found no further north than the lower Yangtze and North Carolina. If the champsosaurs’ temperature requirements were similar, the Axel Heiberg locality must have had mean annual temperatures of at least 14 °C, and the average temperature during the coldest month could not have fallen below 5.5 °C. The region would not even have had ice in winter.

    The champsosaur was not the only warmth-loving reptile to live inside the Arctic Circle. Tarduno’s team has found an abundance of fossils of four kinds of turtles at Axel Heiberg Island, again pointing to a mean annual temperature of at least 14 °C.

    Most recently, the team has found fossils of a family of turtles called Macrobaenidae on Axel Heiberg Island (the details have yet to be published). These turtles originally lived in Asia, but from the late Cretaceous onwards appeared in North America too. Because turtles are very sensitive to climate, the researchers think they could have survived the migration only if they moved along a route in the far north that was warm all year round. More significantly, these turtles – like the champsosaurs – were freshwater creatures. “They would have required a non-marine connection,” says team member Donald Brinkman of the Royal Tyrrell Museum in Drumheller, Alberta, Canada. “If the Arctic was a big freshwater lake, that would have made it possible.”
    Biggest lake

    Fresh water in the Arctic Ocean? As far-fetched as it seems, there is now strong evidence that as recently as 50 million years ago, at the start of the middle Eocene, at least the surface of the Arctic Ocean was fresh. This picture has emerged only recently because it is extremely hard to access the records of the ocean’s history, says Kathryn Moran of the University of Rhode Island in Kingston, a member of a 2004 expedition to drill sediment cores from the Arctic seabed.

    Drill ships have to stay exactly above their chosen site to prevent the drill from snapping, yet in the Arctic drifting chunks of sea ice up to several kilometres wide make normal drilling operations impossible. “They can easily knock a ship off location,” says Moran. “So what we had to do was break that ice.” The task fell to two icebreakers. “The ships are really big and powerful, and they basically had to learn how to dance together,” says Moran.

    Dance they did, and in 2004 the team collected a core of sediment that had been deposited over tens of millions of years on the Lomonosov ridge, just 250 kilometres from the North Pole. One study of the core revealed that a freshwater fern called Azolla grew abundantly in the Arctic Ocean for 800,000 years about 50 million years ago (Nature, vol 441, p 606). At the time the Arctic Ocean was largely isolated from other oceans, and fresh water from rivers would have floated on top of denser salt water. “It might have been, at least in the surface waters, one of the biggest lakes on the planet,” says Moran.
    Surprisingly warm

    The waters of this mega-lake were a surprisingly warm 10 °C, but that’s nothing to the temperatures reached a few million years earlier during the hottest part of the Eocene, when the ocean was salty. According to another study of the core the surface water 55 million years ago was around 18 °C, peaking at an incredible 23 °C – more than warm enough for a pleasant swim at the North Pole!
    The Arctic Ocean peaked at 23 °C, more than warm enough for a pleasant swim at the North Pole!

    What about the Antarctic? Here too gathering evidence is far from easy. Ice cores from Antarctica’s kilometres-thick ice sheets are no help, for even the oldest ice is a mere million years old. It’s the land beneath the ice that holds the secrets. “We don’t want the Antarctic ice sheet to disappear, for there is 67 metres of sea level stored there, but gosh, it would be lovely, from a palaeoclimate perspective, to know what’s under all that ice,” says Wilson. “In particular, because Antarctica has certainly been in a polar position back through the Cretaceous.”

    Fossil hunters on the mainland are limited to a few exposed sites. But on the Antarctic Peninsula, a finger of land that juts north towards South America, enough rock is exposed to give explorers a glimpse not just of Antarctica’s ancient flora and fauna, but of the nature of the seas around it.

    About 150 to 100 million years ago, the peninsula was a mountain range similar to the Andes, and its rivers drained into a massive basin, now called the James Ross basin. Over millions of years, the basin filled up with sediment and later the rocks it formed were uplifted. Today these rocks lie exposed on islands off the Antarctic Peninsula and contain a treasure trove of fossils from the Cretaceous, including silvery slivers of shells of ocean-dwelling ammonites and gastropods. In the late Antarctic summer, these fragments glint as they catch the sun which barely rises above the horizon. “It looks like the surface is covered in jewels,” says palaeoclimatologist Jane Francis of the University of Leeds, UK, a veteran of 12 expeditions to the poles.
    Ferns and cycads

    Besides ammonites and gastropods, Francis and her colleagues have found abundant fossils of sea urchins and lobsters that lived on the sea floor, shark teeth, and even massive marine reptiles with rib bones about half a metre long. Oxygen isotopes in the shell fragments show that the waters around Antarctica 100 million years ago were a balmy 15 °C, compared with -2 to 0 °C today.

    Dinosaur bones, which must have been washed down off the peninsula into the sea, have also been found in the marine sediments (see “Dinosaurs at the poles”). Plant fossils unearthed by Francis and her students show that 100 million years ago the peninsula was lush with ferns and cycads, along with conifers resembling the monkey puzzle tree. Analysis of the shape and size of fossil leaves has led Francis to conclude that the peninsula was very warm during the mid-Cretaceous, with a mean annual temperature of about 17 to 19 °C, similar to that of South Africa today. “That’s almost sub-tropical,” says Francis.

    Growth rings in one fossil tree trunk suggest trees thrived despite complete darkness in mid-winter. “In tree-ring terms, the tree was very happy, it wasn’t growing in any kind of stress, there’s no sign of frost rings and there’s no sign of drought,” Francis says.

    Her team has also found fossil flowers dating back to about 85 million years ago. These include flowers resembling those of Siparunaceae, tropical vines found in the Amazon, as well as those of the Australian eucalyptus and Winteraceae trees such as the Tasmanian mountain pepper.
    Sweltering greenhouse

    It’s abundantly clear that both the Arctic and the Antarctic were ice-free and warm from about 100 million to 40 million years ago. But until a decade ago, climate scientists struggled to explain how the Earth could have become so warm at the poles. Their models suggested it could only have happened if levels of carbon dioxide in the atmosphere were very high – turning the Earth into a sweltering greenhouse – but this would also have made the tropics extremely hot. Isotope ratios in marine shells, however, suggested that tropical waters were not much hotter than they are today.

    As it turns out, the models were right and the shell studies were flawed. Recent and more careful studies by Wilson and colleagues (Geology, vol 30, p 299) suggest that tropical seas were indeed hotter during the hothouse phase, with the surface waters being as warm as 34 °C compared with 29 °C today, says Raymond Pierrehumbert of the University of Chicago, a climate researcher and contributor to the RealClimate blog.

    Despite this advance, climate modellers face a new problem. While pumping up atmospheric levels of CO2 in the models creates ice-free poles and warmer tropical waters, the land in the tropics becomes unbearably hot. “The temperatures are so high that unless land plants behave differently from modern types, you would be beyond their temperature tolerance,” says Pierrehumbert. “We are talking of temperatures on land of an average of 40 °C, and with seasonal fluctuations they might even go up to 50 °C. It would kill off just about anything on land.” Today, annual mean temperatures rarely exceed 30°C.
    We’re talking average temperatures of 40 °C. That would kill off just about anything on land

    As outlandish as these simulations seem, the models might yet again prove to be right. Researchers such as Matthew Huber of Purdue University in West Lafayette, Indiana, have only recently begun to look for evidence of plant dieback in the tropics at this time. No one had thought to look before.
    Too cold

    There is yet another serious problem for climate modellers. The one place the models suggest did get cold during the hothouse episode is the interior of continents at high latitudes – regions like Siberia. This doesn’t fit with the evidence.

    In rocks from the late Cretaceous in Siberia, Robert Spicer of the Open University in Milton Keynes in the UK and his colleagues have found plenty of evidence for ferns and flowering plants, and even possibly the pollen of palm trees (Earth and Planetary Science Letters, vol 267, p 228). Their analysis suggests that at that time Siberia’s mean annual temperature was about 13 °C, rarely touching freezing even in the winter months. “All the climate models give you very, very cold continental interiors [at high latitudes] in the winter time, so cold that you would certainly freeze palm trees and kill them off,” Pierrehumbert says.

    One answer to this puzzle is to keep pumping up the CO2 levels. Models predict that the interiors of continents at high latitudes would not have frozen during the winter if CO2 levels were higher – but this means the tropics would have got even hotter.

    Huber has suggested a possible answer to this dilemma: what if much more heat from the tropics was somehow carried to the poles, keeping the tropics from boiling over. He and Ryan Sriver, also at Purdue, think they have found one possible mechanism.
    Hurricane-ridden

    They studied conditions in tropical waters before and after the passage of present-day cyclones. They found that cyclones mix up the upper layers of oceans, moving heat downward. They argue that ocean currents then transport this heat towards the poles, reducing the temperature gradient between the tropics and the polar regions ( Nature, vol 447, p 577). Many researchers think the intensity, frequency and duration of tropical cyclones increase with higher temperatures. If so, the amount of heat transported to the poles by cyclones would increase greatly as temperatures rise. In a hurricane-ridden hothouse Earth, this could have kept the tropics below 35 °C, while the poles simmered in subtropical heat.

    However, Pierrehumbert thinks that the cyclonic heat-pump idea needs more work, and that explaining the warm interiors of continents remains a challenge. “This is now the most mysterious and toughest looking part of the problem,” he says.

    Others might beg to differ. A few lines of evidence point to something seemingly impossible: ice sheets during the warmest phase of the Cretaceous. “Nobody can imagine that we had these high temperatures and at the same time we had some large glaciers in the Antarctica,” says André Bornemann of the University of Leipzig in Germany. Indeed, models cannot replicate these conditions.

    One recent study by Bornemann’s team suggests that for a 200,000-year period around 91 million years ago, there were ice sheets at least half the size of the ones that blanket Antarctica today. The evidence comes from oxygen isotope ratios in shells from the Atlantic seabed ( Science, vol 319, p 189).

    However, a similar study by Wilson’s team found no evidence of glaciation ( Geology, vol 35, p 615), so this issue is far from settled. But if ice sheets can grow suddenly even during hothouse periods, Wilson point out, it means the climate can change more suddenly and dramatically than anyone thought. “That really demands being understood.”
    High volcanic activity

    Despite these vexing issues, there is a growing consensus that the hothouse climates were due to high levels of CO2 in the atmosphere. But where did it come from?

    Among other things, the amount of CO2 in the atmosphere depends on the balance between volcanic activity and the weathering of rocks. High volcanic activity during the Cretaceous might have kept the level of CO2 high, says Wilson. Later on, volcanic activity may have fallen and weathering increased as the Himalayas began to form, pushing Earth into an icehouse phase.

    However, while CO2 levels up to a million years ago can be directly measured from bubbles of air trapped in ice sheets, it’s much harder working out what they were 100 million years ago. Researchers have to rely on proxies such as the number of pores in fossil leaves, and there are still big uncertainties. Pinning down these numbers is critical, for this would tell us just how sensitive the climate is to rises in CO2.

    Some models suggest CO2 levels were 16 times as high as pre-industrial levels during the Cretaceous and Eocene hothouses, while others suggest eight times. Despite the uncertainties, eight times fits in far better with the proxy data, suggesting that the climate is highly sensitive to rises in CO2.

    This does not bode well for us, given the amounts of CO2 we are dumping into the atmosphere. CO2 levels look set to double from pre-industrial levels and if we keep failing to curb emissions, they could quadruple within 200 years. “Then we are half way towards the CO2 levels that turned the world into the Cretaceous hothouse,” says Pierrehumbert.
    Dinosaurs at the poles

    It is hard to believe that Antarctica once enjoyed a climate warmer than that of England today. Of all the images at odds with that of the frozen continent we know, the one of dinosaurs roaming lush forests is perhaps the most mind-boggling of all.Judd Case of Eastern Washington University in Cheney, Washington, and Jim Martin of the South Dakota School of Mines and Technology in Rapid City have been on many expeditions to hunt for fossils in the James Ross basin on the Antarctic Peninsula.They have analysed the remains of six kinds of dinosaurs, found by them and others, that date from 80 to 65 million years ago – the very end of the age of the dinosaurs.These include a dromaeosaur (a type of meat-eating velociraptor), a hadrosaur (a duck-billed dinosaur), hypsilophodontids (turkey-sized plant-eaters that moved about in herds), iguanodontids (herding dinosaurs that were ancestral to the duck-billed dinosaurs), and nodosaurs (short, squat creatures with armoured plating on their backs). The most impressive find has been the megalosaur, a 6-metre-high carnivore resembling T. rex.On the opposite side of the world, dinosaurs were also ranging around the Arctic Circle. Hypsilophodontids have been found in northern Alaska and hadrosaur bones have been discovered on Bylot Island near Greenland.Case points out that some of the dinosaurs living in Antarctica towards the end of the Cretaceous had already disappeared elsewhere. This is because flowering plants had colonised the warmest regions of the Earth, and dinosaurs had consequently evolved to adapt to the changing vegetation, but not in Antarctica. “It’s one of the last places to get flowering plant fauna,” says Case.The polar dinosaurs would also have had to adapt to long periods of light and darkness. The skull bones of hypsilophodontids suggest that they had large eye sockets, possibly to help with foraging during the dark – but warm – winter months. “There was plenty of greenery, even though it was dark,” says Case. “So there were lots of things for the dinosaurs to eat.”
    http://qbit.cc/when-crocodiles-roamed-the-arctic/

    Comment by prokaryotes — 11 Sep 2011 @ 4:01 PM

  70. Jathanon @46:

    “1. No ice on June 1, 2020
    2. Ice grows again during winter 2020-21
    3. Ice is at 1.7 on June 1, 2021
    4. Ice melts out maybe by July 1, 2021
    5. Ice grows again during winter 2021-22″

    The mistake you’re making is #4: “Ice melts out maybe by July 1, 2021″

    You are assuming that ice extent will melt at at least the same rate of km2/day will melt as currently melts in the high summer. However, there is a key difference: the ice that melts away in the summer of 2011 is much farther south than the new ice that forms in 2021 scenario.

    The new 2021 ice will be right by the north pole, which is colder and gets less solar radiation than the relatively tropical 70 to 75 deg N that melted so fast this summer. Therefore you can’t assume that it will met away at anything like 1.7 million km2/month.

    What these simulations are saying is that new ice will form at the pole in the first winter and persist throughout the first summer. From there it will grow each year until it catches up with ht ever-evolving equilibrium condition.

    Comment by Ernst K — 11 Sep 2011 @ 11:39 PM

  71. I’m merely an engineer and certainly not a climate scientist but over the last few years I’ve been researching climate change and related subjects obsessively, including reading at least half the books listed in RC’s “Our Books” section, along with many other sources. A couple of questions have been keeping me awake at night lately.

    1. Is the RC community familiar with Dan Miller? I was blown away by his presentation “A REALLY Inconvenient Truth.” He communicates very effectively through such vivid examples as a car hitting a brick wall at various speeds. He also explains why we’re not reacting to climate change quickly enough: climate change is too different from threats that humans have faced historically, as he memorably demonstrates by contrasting climate change with a lion on the savanna. His presentation is humorous in a dry dark way, but also serious and engaging. Everyone I’ve shown it to was strongly affected, including some hardened veteran scientists. Dan got tired of watered down facts, and believes that people have the right to know the truth about what’s going to happen to them. I agree. Is there something RC could do to help him?

    2.What is RC’s position regarding Peter Ward and his Medea hypothesis? Is he considered an outlier? I’m wading through his books now. He spends much time debunking the Gaia hypothesis, and I’m sympathetic since I always found it absurdly utopian and typical of 60s new-age thinking. On the other hand Medea handles Fermi’s paradox well, and fits the facts revealed by paleontology: periodic ultra-nasty extinctions dominated by sulphur-compatible bacteria. It seems perfectly rational to me that bacteria would recolonize earth every chance they get, and not surprising that they’ve done so in the past and could do so again sooner than we’d like. It’s a logical consequence of Stephen Jay Gould’s work, the notion that there’s no overall direction in evolution, no better or worse, just fitness (or lack thereof) for endlessly changing conditions.

    3. It seems that RC regularly provides a platform for denizens of the lunatic fringe. The reposting (#69) of the qbit.cc article “When crocodiles roamed the Arctic” is a case in point. The main page of qbit.cc features gas masks, gold prices, ads for colloidal silver, gun nut propaganda, and such amusing topics as “On the 10th anniversary of the fraud known as 9/11…” One of the article’s “related posts” is an Aug 18 article titled “Carbon Dioxide irrelevant in climate debate says MIT Scientist.” How does tolerating such teabagger nonsense further RC’s stated aim of providing “climate science from climate scientists”? Doesn’t it tend to undermine RC’s credibility? And if so, wouldn’t it make sense to simply ban users who repeatedly engage in such behavior?

    Sorry to wade into what is doubtless a controversial issue, but moderation must be more effective if RC is to retain its considerable value. Yes in theory RC doesn’t touch politics, but RC doesn’t exist in a vacuum either. Human society is currently undergoing a monumental and unprecedented convulsion, the outcome of which will largely determine the quantity and quality of life on earth for centuries. The economic and social forces that got us into this mess in first place are more powerful than ever and have much to gain (in the short term) from preventing serious discussion of the reality of climate change and its accelerating impacts. Of course many deniers are only unwitting tools of industry but that doesn’t mean they’re harmless or that giving them a platform doesn’t jeopardize RC’s purpose. A lunatic who falsely cries fire in a crowded theater does mortal harm even though he may believe he’s doing good.

    Comment by Chris Korda — 12 Sep 2011 @ 2:09 AM

  72. MIT study says Arctic ice thinning 4x faster than predicted http://bostinnovation.com/2011/08/10/mit-study-says-arctic-ice-thinning-4x-faster-than-predicted/

    Comment by prokaryotes — 12 Sep 2011 @ 3:56 AM

  73. Chris Korda #71, re: croc(k) postings,

    Well, Prokaryotes did cut and paste his #69 from a loony-bin (and he chose one hell of an anniversary to link to a site peddling those particular conspiracy theories), but according to the attribution, the loony-bin in turn lifted it from the basically sane pages of New Scientist, and sane people are quoted.

    That apart, I share your feelings. Prokaryotes, from one reader to another, please stop posting stuff from crank sites and amateur eccentrics. Link to the legit source when you’ve got one, and if you haven’t got a legit source, don’t bother. Oh, and surely you don’t need to post the full text of a 3,000-word article to make your point, whatever it was.

    Comment by CM — 12 Sep 2011 @ 9:00 AM

  74. RE # 52, Phil. points to the impact of the polarization of light reflected from a transparent media. I can’t disagree against that, however, the issue is the quantity of energy reflected from the surface, not whether or not the SW energy has been polarized. The Brewster angle for the ocean is 53 degrees from Nadir, which is less than the minimum from direct beam at the NP.

    Since apparently no one else found it worth comment, I must correct my post (# 48). The Terra satellite has an equator crossing at 10:30 AM local time, but the highest latitude is crossed 6 hours later in local time at 4:30 PM on the ground. That’s because the orbit crosses the equator from the north-northeast, thus the highest latitude is to the east of the equator crossing. Just shows the confusion which I mentioned. The following graphic shows the orbit tracks for 7 Sept 2011.

    http://tinyurl.com/3ml847a

    Since the time is given in GMT, the crossing at 0 Lon happens to be almost the exact local time of day for every equatorial crossing and one can follow the track back in time to the north-northeast. The highest latitude in the Southern Hemisphere occurs at 4:30 AM on the ground.

    Comment by Eric Swanson — 12 Sep 2011 @ 10:31 AM

  75. Nick Barnes says:
    11 Sep 2011 at 3:28 AM

    Jathanon@46:

    1. No ice on June 1, 2020
    2. Ice grows again during winter 2020-21
    3. Ice is at 1.7 on June 1, 2021
    4. Ice melts out maybe by July 1, 2021
    5. Ice grows again during winter 2021-22

    Where do you get this? From reading the paper, what they do is remove all the ice on July 1, 2020 (not June). In September 2020 there is no ice. In September 2021 there is about 1.7 Mkm^2 of ice. In September 2022 there is about 4 Mkm^2. I’m reading those numbers from figure 1, which only has numbers for September. Where are you getting your numbers for June 1 2021 and July 1 2021? I see no such numbers in the paper.
    ——————————————————
    “sea ice was artificially removed at the beginning of June”, which is where I got June 1. I did, however, miss on the graph that it was for September sea ice extents, assuming it was for the perturbation date. It makes somewhat more sense.

    Re: Ernst K says:
    11 Sep 2011 at 11:39 PM
    I would expect first year ice of that amount to melt fairly rapidly in that situation. Melt of thicker ice currently occurs in the Arctic Basin — and I would not expect the ice to just sit perched at the pole with the gyre and weather systems acting on it, and tenuous or no land connections.

    Comment by Jathanon — 12 Sep 2011 @ 10:41 AM

  76. “I agree kind of hard to reconstruct the correct spot of the crocodile from 383 m years ago, judging from a single site.” – prokaryotes

    Very difficult, since crocodilians did not evolve until the late Triassic (the Triassic was approximately from 250Mya-200Mya). At 383 Mya, the first tetrapods had only “recently” (maybe a few million years earlier) crawled out onto land; the oldest known reptile fossil is Hylonomus, dated at 312 Mya.

    Comment by Nick Gotts — 12 Sep 2011 @ 11:17 AM

  77. RE # 30

    Eric, minor point: You said “Sure, then the sea-ice is covered with fresh snow in winter, the albedo is high”

    No winter albedo. No sunlight.

    John McCormick

    Comment by John McCormick — 12 Sep 2011 @ 12:46 PM

  78. Hey All,

    Just curious if anyone has attempted an experiment of placing a 2.2kg block of ice on a 2.2kg box of sand in a refrigerator at roughly 12 deg. C and blowing air at roughly 1m/s and @ roughly -5 deg. C across its surface to see how long it takes to melt completly. How about placing a heat lamp over the top of the ice so that rough 2.5watts/m^2 are detected on the same ice, to see how long it takes to melt…?

    Has anyone tried repeating the experiments with the air at -1 deg. C, or place the heat lamp so that you can detect 5watts/m^2 at its surface to note the change in melt times.

    Has anyone tried the same experiments in slightly saline water? The point is, neither air temperature or direct IR from CO2 is likely the culprit.

    It is quite clear that the two greatest influences are simple synoptics associated with changes in atmospheric heat content affecting both aerosol/cloud content and warm ocean currents penetrating further into the Arctic Region.

    So what changes cloud cover, 134ppm of CO2, 200 Dobson units of Ozone, or 50Gt of fine ash particles from lower latitudes. Could it be the 0.7 deg. C warming of the atmosphere at an average altitude of 4km? Maybe it is simply a atmosphere in a synoptic phase of extremes that was common 10kya. To my knowledge the largest global change between 10kya and 7.5kya was the greening of the planet. To my knowledge the biggest change to the p.anet since the early 1800s and today was the denuding of the planet. The removal of at least 1/2 or 90Gt of uptake capacity or nearly twice the emmissions of fossil fuels since 1800 has more to do with the changes we see then the change in C12-13 isotope levels. Combined with changes in both soil moisture and aquafir levels is significant, why is this not part of this discussion?

    Cheers!
    Dave Cooke

    Comment by L. David Cooke — 12 Sep 2011 @ 1:05 PM

  79. #47, Pete Dunkelberg,

    I second your request for informed debate; informed by people reading the paper at hand.

    It has been claimed that this is a model study, and as models are clearly failing to reproduce the observed sea-ice trends in the Arctic, the study can be dismissed. This is not correct.

    Whilst one may disagree with the timescale to seasonally sea-ice free state implied by Tietsche et al (I for one do). The process outlined, loss of energy into the atmosphere and thence a) radiation to space, b) reduced inward atmospheric heat flux (figure 3b of Tietsche), is happening now in the Arctic atmosphere. OK, it’ll be happening in the next few months, for yet another year.

    For example, figure 4 of Overland & Wang shows a lower troposphere warming centred on the area of open water at the end of the melt season during the period October to December. This is observed in NCEP/NCAR reanalysis together with a substantial impact on geopotential height anomalies (Overland & Wang figure 6).

    Compare these observations with figure 3 of Tietsche et al; where it is seen that during the period of recovery there are large negative (outgoing) fluxes of longwave radiation, and sensible (that which can be sensed) and latent heat. The latter alone implies disturbance to the atmospheric column as shown in Overland & Wang figure 6.

    Overland & Wang
    “Large scale atmospheric ciculation changes are associated with the recent loss of Arctic sea-ice.”

    Comment by Chris R — 12 Sep 2011 @ 2:30 PM

  80. RC made the NYT Dotearth blog again at:
    http://dotearth.blogs.nytimes.com/2011/09/12/the-arctic-ice-watch/
    1 Mac and 4 wmar made outrageous comments there.

    Comment by Edward Greisch — 12 Sep 2011 @ 3:29 PM

  81. German Physicists: Historic Low Arctic Ice is a “Consequence of Man-Made Global Warming with Global Consequences”
    http://thinkprogress.org/romm/2011/09/12/317157/arctic-ice-global-warming/

    Comment by prokaryotes — 12 Sep 2011 @ 4:28 PM

  82. Nick Gotts “Very difficult, since crocodilians did not evolve until the late Triassic”

    “Tiktaalik generally had the characteristics of a lobe-finned fish, but with front fins featuring arm-like skeletal structures more akin to a crocodile, including a shoulder, elbow, and wrist. The fossil discovered in 2004 did not include the rear fins and tail. It had rows[12] of sharp teeth of a predator fish, and its neck was able to move independently of its body, which is not possible in other fish. The animal also had a flat skull resembling a crocodile’s” http://en.wikipedia.org/wiki/Tiktaalik

    The Fram Formation is a Late Devonian sequence of rock strata on Ellesmere Island that came into prominence in 2006 with the discovery in its rocks of examples of the transitional fossil, Tiktaalik, a sarcopterygian or lobe-finned fish showing many tetrapod characteristics. The Fram Formation is a Middle to Upper (Late) Devonian clastic wedge forming an extensive continental facies consisting of sediments derived from deposits laid down in braided stream systems that formed some 375 million years ago,[1] at a time when the North American craton (“Laurentia”) was straddling the equator. http://en.wikipedia.org/wiki/Fram_Formation

    Comment by prokaryotes — 12 Sep 2011 @ 4:37 PM

  83. Re. 80 Esward Greisch.

    I see Goddard got invited over by Revkin, too. Apparently, multiyear Arctic sea ice is recovering so the evil cabal has switched to sea ice area. Wow, that’s some recovery. “Remove the stitches nurse, the patient’s head is sure to stay attached this time.”

    Comment by J Bowers — 12 Sep 2011 @ 6:32 PM

  84. Criminy prokaryotes, I thought 69 was supposed to be fun!

    Comment by Jbar — 12 Sep 2011 @ 6:55 PM

  85. Prokaryotes, your own quote says that Tiktaalik was a fish, from a region that straddled the equator.

    Comment by Philippe Chantreau — 12 Sep 2011 @ 6:59 PM

  86. > multiyear ice

    D’oh. After a record low like 2007 or 2011, _any_ ice that persists through the following several years will count as an increase over the starting low.

    I know someone pointed that out in 2008 replying to similar

    Comment by Hank Roberts — 12 Sep 2011 @ 7:14 PM

  87. “After a record low like 2007 or 2011, _any_ ice that persists through the following several years will count as an increase over the starting low.”

    Yes. In Watts land, the ice is always recovering, but this is, dare I say, ‘the best of all possible recoveries.’

    Comment by Kevin McKinney — 12 Sep 2011 @ 9:59 PM

  88. Thought I was going mad following this thread. A lobe-finned fish skeleton is found. Someone describes it as “crocodile-like” referring to its tendency to walk with legs kinda horizontal, belly on ground; and to its presumed use of both water and water edge habitat. Nothing to do with crocodiles in an evolutionary or taxonomic sense (and long preceding them) just a kind of ecological analog to help people picture the behaviour and ecology of an extinct speces. But someone sees “crocodile” thinks “tropical crocodiles” in the Arctic and away we go on a wild lobe-fin chase. Ignoring all the misunderstanding about the species being referred to, and a complete lack of appreciation of continental drift, what on earth would an “ice free Arctic” several hundred million years ago have to do with the melt of the Arctic over a few decades now? Denialism is clutching at thinner and thinner straws.

    Comment by David Horton — 13 Sep 2011 @ 12:33 AM

  89. #89 prokaryotes, the MIT article nails almost completely the missing links explaining ice model failures, thanks for it and the Ellesmere pieces. Ice physics is said complex because they fail to predict its behavior while likely missing factors, I call them vectors, 5 of them, wind, current, tides,morphology (ice shapes in the wind and under water) and ice momentum, that is with respect to the ice only. Then there is the atmosphere and sea water, the latest crucial atmospheric component are “boundary layers” , their effects are huge, I study them closely, and of late they are vanishing along with the ice, the very isothermal micro layers above the sea act as a buffer and or cut off heat exchanges between sea and air, surface air may be -35 C but right above much warmer. These isothermal layers rise during summer, but when they dont drop there is rather a complex (because I don’t know what sea component does) heat exchange at the interface of water and air which melts the ice further or stops it from forming. When the sea surface is warmer than the the air the exchange exacerbates the adiabatic lapse rate. Therefore its not surprising that the models fail, 4 times faster is a misnomer, the process of flushing is a matter of the vectors all moving in the same direction towards the North Atlantic. There could have been no ice at the North Pole this summer, but the vectors were diverging in all directions quite irregularly but often overall more North Atlantic bound in synergy than during the summer of 2010. I suspect the thermal signature of the ocean, its weighted equivalent temperature, at or near sea surface being also quite critical.

    Comment by wayne davidson — 13 Sep 2011 @ 1:21 AM

  90. David Horton @ 88, granted Tiktaalik is a red herring. But more than one comment above is floundering, including yours if you think Prokaryotes is a denier. ;)

    Comment by Pete Dunkelberg — 13 Sep 2011 @ 8:02 AM

  91. Would it be fair to say that the low ice extents from 2008-2011 are really the same low ice extent of 2007? I’ve seen reports of a new record low hit this year and I’m trying to determine if this is a new event or if this is really just current state of the 2007 ice loss which NASA attributed to ‘unusual winds’ ‘set up by an unusual pattern of atmospheric pressure that began at the beginning of this century’

    ‘http://www.nasa.gov/vision/earth/lookingatearth/quikscat-20071001.html’

    Also, a request for clarification on the following line from this report:

    ‘The scientists observed less perennial ice cover in March 2007 than ever before’

    When the report says ‘than ever before’, does it mean since 1979 like many of the posts here specify? or does it actually mean ‘than ever before’ which are two very different things. Thank you.

    Comment by Tad Boyd — 13 Sep 2011 @ 9:50 AM

  92. I’ve seen reports of a new record low hit this year and I’m trying to determine if this is a new event or if this is really just current state of the 2007 ice loss which NASA attributed to ‘unusual winds’ ‘set up by an unusual pattern of atmospheric pressure that began at the beginning of this century’

    The weather patterns this September have not been as amenable to compaction (blowing ice together) as in 2007, so, no.

    But before fully adapting the denialist spin on 2007 being “due to unusual winds, not global warming” consider asking yourself “why was the ice so thin and weak in 2007 that the wind could compact it to such an extent”.

    Comment by dhogaza — 13 Sep 2011 @ 11:24 AM

  93. Tad Boyd, read this and look at the graphics(@link).

    Arctic sea ice has melted to a level not recorded since satellite observations started in 1972 – and almost certainly not experienced for at least 8,000 years, say polar scientists.

    Daily satellite sea-ice maps released by Bremen university physicistsshow that with a week’s more melt expected this year, the floating ice in the Arctic covered an area of 4.24 million square kilometres on 8 September. The previous one-day minimum was 4.27m sq km on 17 September 2007. http://climatecrocks.com/2011/09/12/down-to-the-wire-arctic-ice-close-to-bottom-we-hope/

    Comment by prokaryotes — 13 Sep 2011 @ 11:49 AM

  94. Tad #91 It would be fair to say they’re a continuation of the low extents seen in 2007, though volume losses have decreased even further. Volume in 2011 is down nearly 40% compared to 2007.

    I’m sure they mean since scientists have been studying the Arctic. Scientists believe that 45 to 50 MYA the arctic was ice free – of course they were unable to actually observe it. Append ‘in recorded human history.’ I.e. — The scientists observed less perennial ice cover in March 2007 than ever before in recorded human history.

    Comment by Kevin O'Neill — 13 Sep 2011 @ 11:59 AM

  95. Thanks Kevin and prokaryotes, I’ve been having a hard time quantifying “then ever before” in the NASA report (and other places similar terms have been used).

    dhogaza, I was referring to the NASA report at
    ‘http://www.nasa.gov/vision/earth/lookingatearth/quikscat-20071001.html’

    The report didn’t go into whether or not there was a global warming link though the study it was referring to may well have. It did say that the loss of thick, year-round sea ice cover during the previous 2 winters was the primary cause.

    I don’t think that Dr. Ngheim of NASA posts here at RealClimate but I know some NASA scientists do so was hoping to get clarification from as close to the source as I could on what ‘than ever before’ meant. You’d be suprised at how many family gatherings arctic ice comes up in conversations and none of us really knows what time period we are talking about when discussing the lowest ice extent ‘than ever before’

    Thanks again.

    Comment by Tad Boyd — 13 Sep 2011 @ 1:09 PM

  96. NSIDC has a new report out, but they have not yet declared a new record minimum.

    http://nsidc.org/arcticseaicenews/

    But, as they say, the slight differences between the different centers because of their differing data gathering techniques does not significantly alter the larger picture:

    “While the University of Bremen and other data may show slightly different numbers, all of the data agree that Arctic sea ice is continuing its long-term decline. “

    Comment by wili — 13 Sep 2011 @ 1:23 PM

  97. Pete #90

    > … red herring … floundering …

    Not to carp, but you know, when your sole cue about someone is they’re sounding fishy, or talking cod‘s wallop, they can be hard to plaice, uh, place. And noone wants to be a sucker with so many sarcastic fringeheads around. Now, can we get back to the surf smelt, uh, I mean, the surface melt? :-)

    Comment by CM — 13 Sep 2011 @ 2:13 PM

  98. #96 wili

    Thanks for posting that link wili. nsidc was specific about the time period they were speaking of:

    ‘In the last few days, the decline in Arctic sea ice extent has slowed. NSIDC data show Arctic sea ice extent currently at the second-lowest levels in the satellite record’

    I don’t yet know if ‘than ever before’ (from my post #91) equates to ‘since scientists have been studying the arctic’ or ‘in recorded human history’ or the more specific ‘in the satellite record’ But the NSIDC was very clear.

    A little further down in the NSIDC report and as you mentioned in your post wili:

    ‘Arctic sea ice is continuing its long-term decline’

    Brings up another question: ‘long-term decline’ – Could that also be since the satellite record began? or is that something like since the Northern Hemisphere Little Ice Age? Or maybe longer?

    I realize I could ask questions all day long so I’ll try to make this my last question for this topic. wili’s post and link were just too close to what I was trying to figure out, to not ask. Thanks.

    Comment by Tad Boyd — 13 Sep 2011 @ 2:30 PM

  99. #98 found the answer to my own question on the NSIDC site. Posting here so no-one will spin there wheels on it. Thanks.

    ‘Yes, the data show that Arctic sea ice really is in a state of ongoing decline. The reason we know this is because satellites offer us a long-term record’

    NSIDC considers the satellite record to be a long term record so hopefully I’m getting the context right in concluding that the long term decline means since we’ve been keeping track with satellites

    ‘http://nsidc.org/arcticseaicenews/faq.html’

    Comment by Tad Boyd — 13 Sep 2011 @ 3:30 PM

  100. There’s sufficient data from shipborne observations to be sure that the decline in Arctic sea ice is unique at least since the beginning of the 20th century. There’s sufficient evidence from paleoclimate indicators to say with confidence that the pressent low levels of sea ice are unique for at least several thousand years.

    Comment by tamino — 13 Sep 2011 @ 3:31 PM

  101. OK guys. Having something “like” recaptcha to reduce spam is fine. But now it expects me to type (in the little box) the partial derivative of omega with respect to z. No, I don’t mean its description in words — I mean the partial derivative sign, and the Greek letter omega.

    This is ludicrous. You do NOT serve your purpose by making it prohibitively difficult to post comments. It would serve you well to think more highly of your readers — because this kind of obstacle indicates otherwise.

    Comment by tamino — 13 Sep 2011 @ 3:34 PM

  102. Tad, beyond the satellite or other human observations, sedimentary layers show whether the plankton was of kinds that thrive in open water or under ice.
    You’ll find a lot in Scholar; here’s one as an example:

    http://europa.agu.org/?uri=/journals/jc/jc0803/2007JC004202/2007JC004202.xml&view=article

    Paleo–sea ice conditions of the Amundsen Gulf, Canadian Arctic Archipelago: Implications from the foraminiferal record of the last 200 years

    Comment by Hank Roberts — 13 Sep 2011 @ 3:48 PM

  103. NSIDC has a new report out, but they have not yet declared a new record minimum.

    But I did. I have been suspecting it for a while now, but with the latest NSIDC report and the upticks on the IJIS sea ice extent graph, I’m quite certain that the melting season has come to an end and the minimum has been reached in most, if not all data sets.

    Tamino, I always refresh the captcha (one of very small buttons in the mddile) if I can’t read it. I never saw one of those symbols you mention, but then again, I wouldn’t recognize them (except for the omega of course). :-)

    Comment by Neven — 13 Sep 2011 @ 4:04 PM

  104. Tad, there is declassified US submarine track data showing Arctic ice thickness and extent that extends the long term decline back to the early 1960s. Late 1960s high-res weather satellite imagery showing the arctic basin is currently being reprocessed, which presumably will do the same.

    Comment by Jim Eager — 13 Sep 2011 @ 4:19 PM

  105. Tamino: But now it expects me to type (in the little box) the partial derivative of omega…[general annoyance]

    So it’s probably not a good idea to implement the full plan in which comments will be earned by actually solving a partial derivative. :-)

    (ominous recaptcha: “function rsfInfo,” I kid you not!)

    Comment by Doug Bostrom — 13 Sep 2011 @ 4:20 PM

  106. Thanks tamino, Hank, Jim, All
    You’ve given me lots of direction for further research as I try to put together some of the pieces of the arctic sea ice picture, and what it means, for myself.

    Comment by Tad Boyd — 13 Sep 2011 @ 5:10 PM

  107. “So it’s probably not a good idea to implement the full plan in which comments will be earned by actually solving a partial derivative. :-)”

    Well, it might reduce the scientifically illiterate comments. But as it would rule me out, I’d selfishly vote against–presuming a vote was held, and I got one!

    On another topic, Neven’s methodology always works for me, and, like Tamino, I have got some Captchas with arcane symbols. But just hit the little ‘arrows’ icon, and hey presto. . .

    Speaking of Captcha, it’s giving me “personnel snacess.” Close enough. . .

    Comment by Kevin McKinney — 13 Sep 2011 @ 5:48 PM

  108. NSIDC confirm that Bremen data is high resolution, possibly record minimum for past 8000yrs

    http://blogs.nature.com/news/2011/09/arctic_sea_ice_drops_to_record.html

    Comment by john byatt — 13 Sep 2011 @ 6:02 PM

  109. At NSIDC

    “Other sea ice data are available from other data providers, using different satellite sensors and sea ice algorithms. For example, data from the University of Bremen indicate that sea ice extent from their algorithm fell below the 2007 minimum. They employ an algorithm that uses high resolution information from the JAXA AMSR-E sensor on the NASA Aqua satellite. This resolution allows small ice and open water features to be detected that are not observed by other products. This year the ice cover is more dispersed than 2007 with many of these small open water areas within the ice pack. While the University of Bremen and other data may show slightly different numbers, all of the data agree that Arctic sea ice is continuing its long-term decline.

    .

    Comment by john byatt — 13 Sep 2011 @ 7:46 PM

  110. Tad. you’re in luck.

    Patrick Lockerby has just done one of his history of science pieces …. on Arctic warming. There’s an earlier one using historic maps but I didn’t find it just now. http://www.science20.com/chatter_box/brief_history_arctic_warming-82545

    Comment by adelady — 13 Sep 2011 @ 8:05 PM

  111. 91Tad Boyd :

    “Would it be fair to say that the low ice extents from 2008-2011 are really the same low ice extent of 2007? I’ve seen reports of a new record low hit this year and I’m trying to determine if this is a new event or if this is really just current state of the 2007 ice loss which NASA attributed to ‘unusual winds’ ‘set up by an unusual pattern of atmospheric pressure that began at the beginning of this century’”

    No…

    The local small glaciers on Cornwallis Island have disappeared gradually over 2007-2011 till now
    where they are mostly all gone leaving very little traces of their existence, like ruins from an ancient city
    reminding us of a once upon a time colder period.

    Big wind systems have always existed over the Arctic ocean, the term “unusual winds” is nonsense. The more proper term would be consistent winds towards the North Atlantic is better, and is equally not so rare, in fact it is so frequent as to give the sea surface currents. Present day satellite pictures suggest a total lack of cohesion of the Arctic ocean ice pack as compared to decades ago. Lack of old multiyear ice basically ensures a loose pack, free to move wherever the tides, sea current, winds and momentum takes them. I suggest it possible to have far less resulting ice at minima given the right winds, timed again with non conflicting tides, along with the usual sea currents and proper momentum (the big gorilla, massive from consistent long lasting flows). What can be said since 2007 is that summer ice has been spared by really “unusual” winds and timely clouds. If the melt bottomed as contrarians suggest then I would see evidence of that elsewhere, on the flanks of Arctic hills especially.

    No 103 Hi Neven, I agree with NSIDC waiting for declaring us at minima. Surface air temperatures over the Arctic ocean must be colder than -11 C, it was detected so by daring scuba divers from France near the Pole, noticing ice bottom 2 meters thick disintegrating or melting when surface temps were -11 C. So I surmise -10 to -15 C weather is needed to start the long freezing season. I checked the -11 C in the Arctic here and it works with open water with last few years freeze-ups. -5 C doesn’t cut it.

    Comment by wayne davidson — 13 Sep 2011 @ 9:59 PM

  112. #111 Thanks Wayne. That helps to paint a clearer picture. The temperature/ice melt/re-freezing correlation gave me another piece of context to understand the discussion with. (i.e. even though the temps are below freezing, it doesn’t mean the ice is maintaining [or now increasing])

    #110 adelady. The link you provided hit the nail square on the head for helping me with the ‘what time period does long term decline’ cover concerning arctic sea ice decline and may be at least a sample of what tamino was referring me to in post 100 about the available data from shipborne observations. This line from ‘A Brief History of Arctic Warming’ that you linked to, appears to support that the long term decline in arctic sea ice may have been in progress at least since 1818.

    ‘From the reopening of access to Baffin Bay in 1818 and the reopening of the sea route from Kolyma to Bering Strait around 1879, there has been a clear and almost continual change in the behavior of Arctic ice. The rate of that change has accelerated and appears to be accelerating more.’

    That is the kind of context (as well as what all of the other posters have directed me to) that I am looking for so I at least have a chance of understanding what news reports, NASA reports, (family members at family gatherings), and other reports are referring to.

    Thanks again. I haven’t had a chance to check out all of paths you all have provided but I will keep reading.

    Comment by Tad Boyd — 14 Sep 2011 @ 1:13 AM

  113. Whilst a record low might be interesting, isn’t it more important that we are seeing a 2nd ice extent event in 5 years that is around 4 standard deviations below the 1979-2000 average? I suggest we can now be confident in stating that we are seeing the start of a transition from the stable climate Earth has enjoyed since the end of the last glacial period. The question is whether that transition can be halted.

    Comment by ian perrin — 14 Sep 2011 @ 1:23 AM

  114. 59. Phil at http://community.nytimes.com/comments/dotearth.blogs.nytimes.com/2011/09/12/the-arctic-ice-watch/?sort=oldest&offset=3
    says:

    Large Variations in Arctic Sea Ice: Polar Ice Much Less Stable Than Previously Thought, Study Finds
    http://www.sciencedaily.com/releases/2011/08/110804141706.htm

    which says: “During the so-called Holocene Climate Optimum, from approximately 8000 to 5000 years ago, when the temperatures were somewhat warmer than today, there was significantly less sea ice in the Arctic Ocean, probably less than 50% of the summer 2007 coverage, which was absolutely lowest on record.”

    What is going on?

    Comment by Edward Greisch — 14 Sep 2011 @ 1:32 AM

  115. 114, Edward Greisch – There was a short discussion of this in the August unforced variations thread.

    The high temperatures during the Holocene Climate Optimum were largely associated with greater insolation in the Northern Hemisphere due to orbital mechanics. Temperatures in the Arctic were most likely ‘somewhat warmer’ than today due to the enhanced NH insolation but I think the global average wouldn’t have been much warmer than today, if at all, because the Southern Hemisphere would have experienced decreased insolation over the same period.

    Comment by Paul S — 14 Sep 2011 @ 7:49 AM

  116. re: 113

    The extent and area records this year are made worse by the fact that volume this year is a std.dev. less than in 2007. There’s far less ice this year than in 2007.

    Comment by Jeffrey Davis — 14 Sep 2011 @ 8:16 AM

  117. Paul S, not just the Southern Hemisphere, but also regions closer to the equator: the Serbian Barbecue has several components, and while increased obliquity produces more high-latitude insolation, it does so on the polar areas of both hemispheres. Precession together with orbital eccentricity OTOH would produce more summer insolation on one hemisphere but less on the other, producing the effect you describe.

    Milankovic cycles

    Comment by Martin Vermeer — 14 Sep 2011 @ 8:31 AM

  118. @ 114, 115: the paper of Funder et al. A 10,000-Year Record of Arctic Ocean Sea-Ice Variability—View from the Beach
    has been discussed several places.

    Moving ahead just a little we come to Rampal et al., also already discussed but did not get enough attention imho.

    Comment by Pete Dunkelberg — 14 Sep 2011 @ 9:33 AM

  119. RE:117

    Hey Martin,

    So can vegetation sequestration. It depends on whether the active element/organisms are UV or are Human Species destructive activity sensitive.

    I maintain we continue to look at cause and effect via a narrow scope when we likely need to apply a richfield scope. When there are multiple contributors it is very difficult to isolate contributing factors without the ability to “tag” sources. Oxygen isotopes associations help, as do others.

    I believe as we improve the richness of the datasets the correlations shall improve. We have a bit further to go yet, if my logic/critical thinking process is right… It requires many years and filled gaps between specialties to advance this science. I hope I get to see the conclusion.

    Cheers!
    Dave Cooke

    Comment by L. David Cooke — 14 Sep 2011 @ 10:08 AM

  120. #117, Thanks Martin, I thought I might have some of the details wrong after I posted so have been doing a bit more research. Could you explain the ‘Serbian Barbecue’ reference? A google search only brought up, well, Serbian barbecues.

    Comment by Paul S — 14 Sep 2011 @ 11:22 AM

  121. “….throughout the entire satellite record…” yer man writes. Entire? As in “that’s the best meal I’ve eaten in my entire, er, week!”m

    Comment by Brent Hargreaves — 14 Sep 2011 @ 12:15 PM

  122. Proof of further melting since 2007 can be seen in the NW and NE Arctic passages, clear and wide with sea for a plastic bath tub of a boat to travel. In particular in the Canadian Archipelago, more or less wind neutral because of the many channels and Islands which obstruct the winds from massing ice over its waters.
    This again is reflected in its small land glaciers, almost all completely gone. We can see the further melt since 07, difficult to dissociate with mechanical forces as with over the Arctic ocean, but clearly seen from space in the Arctic navigation channels..

    Comment by wayne davidson — 14 Sep 2011 @ 1:02 PM

  123. “….throughout the entire satellite record…” yer man writes. Entire? As in “that’s the best meal I’ve eaten in my entire, er, week!”

    “No warming since 1998″ meet “only 32 years of satellite data? means nothing!”.

    Gotta admit that denialists flat-out cherish consistency …

    Comment by dhogaza — 14 Sep 2011 @ 2:07 PM

  124. “Gotta admit that denialists flat-out cherish consistency”

    Except when they start trying to explain global warming, in which case they have over 160 inconsistencies ;)

    Comment by J Bowers — 14 Sep 2011 @ 2:59 PM

  125. At the risk of beating a dead horse, here’s more proof that the albedo of sea-ice isn’t as large as most people seem to think:

    http://i454.photobucket.com/albums/qq268/Know_body/GRENFELL2006T1.jpg

    This table is taken from: Grenfell, et al., “Energy and mass-balance observations of the land–ice–ocean–atmosphere system near Barrow, Alaska, USA, November 1999–July 2002″, Annals of Glaciology 44 2006. Notice the reduction in albedo reported for melt ponds and dirty sea-ice. Now consider the impact of large zenith angle at high latitudes on the albedo of the ocean.

    Comment by Eric Swanson — 14 Sep 2011 @ 3:42 PM

  126. I’m still convinced the minimum has been reached for IJIS and NSIDC extent. I’ve compared the two biggest melt years on record:

    Final score: 2007 vs 2011

    Comment by Neven — 14 Sep 2011 @ 5:47 PM

  127. #125–OK. But did you note the figure for open water?

    Comment by Kevin McKinney — 14 Sep 2011 @ 6:00 PM

  128. “Serbian barbecue”: Milankovic was a Serb. Kind of an obscure allusion, I guess.

    Comment by Mal Adapted — 14 Sep 2011 @ 6:09 PM

  129. Re: #127 Kevin McKinney mentions the low albedo number given in my reference, comment #125. From the referenced report, we find this comment:

    “The final albedo values after the ice had melted are taken to be 0.07 following Pegau and Paulson (2001)”

    In other words, the referenced report didn’t actually measure the local open water albedo. I suppose that’s where I have my disagreement. I’ve tried to find the data from that report, which was collected during the SHEBA experiment, but I’ve had no success. I think their data was deleted from the SHEBA site at U Washington. Pegau and Paulson’s experimental setup was rather flaky, if you ask me, as they hung their measurement instruments off the rear of a small skiff floating in a lead, which could not be considered a stable platform and they did not provide any information regarding the weather conditions, such as the amount of overcast or the total insolation…

    Comment by Eric Swanson — 14 Sep 2011 @ 7:27 PM

  130. Hey Mal,

    If I do not miss my guess Martin (Re:117), was referencing the Serbian Traps as an example of a complication to observations for hemispherical variances. The point is there are localized variations which can occur; however, eventually they will become fully distributed reducing their local impact; however, impacting the globe at a diminished level.

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 14 Sep 2011 @ 9:44 PM

  131. No, it’s Siberian traps. I don’t know where Martin came up with Serbian barbecue, but they are supposed to be very good.

    Comment by Greg Simpson — 14 Sep 2011 @ 11:31 PM

  132. Hey Greg,

    Of course you are correct, I simply over looked the differences and replicated the obvious error.

    Cheers!

    Comment by ldavidcooke — 15 Sep 2011 @ 7:46 AM

  133. #114 Edward Greisch,

    An important preceding paper to read w.r.t. Funder et al is Jakobsson et al 1010. “New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling.” Their figure 2 shows that relative to current levels (~425W/m^2), 65degN July insolation was around 470W/m^2.

    So during the Holocene Thermal Maximum, when the Arctic probably had lower levels of sea ice than now, July 65degN insolation was 10% higher than present.

    Comment by Chris R — 15 Sep 2011 @ 12:16 PM

  134. > Siberian traps

    http://siberia2009.wordpress.com/ blogs an expedition collecting rocks.

    The Siberia Project Main Page
    siberia.mit.edu

    Comment by Hank Roberts — 15 Sep 2011 @ 2:51 PM

  135. Hm, nothing I’ve tried to add for several days has showed up. Boring ya?

    Comment by Hank Roberts — 15 Sep 2011 @ 3:25 PM

  136. Might not be boring.

    Pielke Sr attacks SkS out of nowhere

    SkS answers back

    Pielke returns (sort of)

    You can follow updates on ‘SkS answers’ post.

    Comment by grypo — 15 Sep 2011 @ 5:12 PM

  137. My comment should be in the open thread. Sorry.

    Comment by grypo — 15 Sep 2011 @ 6:28 PM

  138. “There has not been warming significantly, if at all, since 2003, as most everyone on all sides of the climate issue agree….” (Pielke returns)

    Comment by Hank Roberts — 15 Sep 2011 @ 6:38 PM

  139. #138 Hi Hank, go to my blog, http://eh2r.blogspot.com/, see the Pielke stall in action. By the way, I need goole earth latest 2011 pictures, how to get I wonder?

    Comment by wayne davidson — 16 Sep 2011 @ 10:29 AM

  140. #138 Hank, Go to http://eh2r.blogspot.com/ and see Pielke’s temperature stall in action. Need to know if it is possible to get summer of 2011 Google Earth pictures as well,
    further proof awaits.

    Comment by wayne davidson — 16 Sep 2011 @ 1:55 PM

  141. I notice that th word “wind” is mentioned seven times here but never in relation to the NASA study about the Arctic ice low in 2007 being caused by the wind

    http://www.nasa.gov/vision/earth/lookingatearth/quikscat-20071001.html

    Is it different now?

    [Response: It wasn't different then. You are confusing proximate causes with ultimate ones. The wind patterns in 2007 were not exceptional, but they had an outsize effect because there was much less ice. In every year, the specifics of the winds and weather affect the final minimum, but the long term trends are not related to wind changes. - gavin]

    Comment by Andre — 16 Sep 2011 @ 3:16 PM

  142. Could you explain the ‘Serbian Barbecue’ reference?

    Paul S, Mal Adapted got it right: it is an obscure reference to the Milankovic mechanism.

    Note to self: don’t invent inside jokes when explaining something. The excuse I have is that during the Apollo Project — yes I’m that old — reference was made to barbecue mode for the thermal management of that spacecraft. Appropriate metaphor, no?

    Comment by Martin Vermeer — 17 Sep 2011 @ 6:57 AM

  143. ““There has not been warming significantly, if at all, since 2003, as most everyone on all sides of the climate issue agree….” (Pielke returns)”

    Funny how the recent period during which it hasn’t been warming significantly keeps getting shorter and shorter. I remember, seems like it was as recently as early this year but maybe it was late last year, when it was “since 1995″.

    Comment by Jon — 17 Sep 2011 @ 11:09 AM

  144. RE: 141

    Hey Martin,

    Then congratulations to Mal, though now your point leaves me a bit confused. Granted there is wobble or at least a slight variation in the angle of rotational axis of the Earth in relation to the solar equitorial plane; however, I find myself confused as to how that may cause a difference in either solar insolation or hemispherical warming.

    Granted if we are talking of a deviation of 30 degrees I could see your point. But how does 5-7 degrees significantly change global temperatures. Are you suggesting that the angle of inclination varies between 30 and 23 or are you suggesting a dfference of between 30 and 16 degrees? If the latter and we are only 1/2 way towards the terminal value how much warmer could it get? If we are talking of the former then are we approaching the return? So how much does the climate currently change across 5-7 degrees of a temperate zone?

    The reason for asking is if wobble influences the GAT then I find the ice core work of Dr. ALLEY and others to be in jeporady, if the global average record rises to a peak, falls away, in a pattern of durable cooling with periodic warm extremes roughly every 100ky, rapidly hitting a peak again, kind of reminds me of a top about to fall over. A wobble of this magnitude I do not believe has been demonstrated as the character of the Earth, unless you are suggesting a rotational inversion of the Earths crust. Of course even then I would wonder if the solar insolation would change much…

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 17 Sep 2011 @ 2:41 PM

  145. RE:143

    Hey All,

    Just to update the accuracy of the last post a bit, the inclination of Earths rotational axis in relation to the solar equitorial plane (obliquity) is between roughly 21 and 24 degrees. As to the orbital variation it appears the value to be approximately 3 million miles between a near circular versus eliptic maximum. Hence a L1 larange satellite at 150km towards the Sun with a photometer / pyrometer should provide a clue as the possible additional insolation. The biggest question is the possible tilt of Earths orbital plane as there are some indications of dust which may be shading Earth a bit at times.

    This leaves the question of insolation variation being a participant climate change. As of a few years ago I would have suggested that solar activity variation might account for up to 6 watts variation. Based on the latest data I do not know that this is accurate any longer. If you were to add in CO2s estimated 2.5 watts (Hansen 05) and the orbital variation they might have added up to a 0.3-4% variation in the average insolation reaching the Earth. Whether this is enough to account for a 0.7 deg.C increase in GAT and a possible 7deg. C increase in Arctic air temperatures is an interesting thought, I am just not sure that this is a significant contributor.

    Though additional ocean heat, (due to reduced cloud cover and CCN aerosols near the equator or Arctic Circle) being carried far into the Arctic ocean region by ocean currents, evaporation, convection, advectation, all affecting the atmospheric currents with changes in Blocking and Cutoff systems, I believe is supportable. Now if we add in the insolation changes noted earlier it would appear that the combination of multiple contributors may be significant.

    The hard part is in the attempt to identify all the various contributors and the weight they add to the mix. Though many may be at loggerheads, I believe there is an element to the many points of view, some more then others. The diffcult thing is trying to make a place for everyone at the table when there are limited place settings. Eventually it will be resolved, I hungerly anticipate that day…

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 17 Sep 2011 @ 6:34 PM

  146. Eureka of sorts, especially for contrarians, and also for those pursuing the rate of planetary warming.
    I’ve added an old picture of small high Arctic glaciers on Cornwallis Island on my blog, didn’t realize how many of them have vanished over the years, really noticed their disappearance in the last few summer seasons though.
    Their melt was slow but steady accelerating within the last few years. Like the last small ice sheets have really no chance.
    The key is to take earthsat platforms and count their yearly extinction rate. It would be very practical and extremely convincing for especially skeptical scientists of all stripes! Have a look before you claim a lull in the warming. Evidence by white ice spots, here http://eh2r.blogspot.com/ is proof of heating of the Arctic as predicted, the albedo effect over permafrost lands.

    If someone has access to old high res polar orbiting sat pictures similar in resolution to Google Earth, You are it! Go and display, and put to bed the latest skeptics myth in no time.

    Comment by wayne davidson — 18 Sep 2011 @ 2:16 AM

  147. Re 143 & 4

    Hi Dave,

    Obliquity does not change solar insolation but it it does change the Earth’s albedo because it moves the Arctic Circle, and influences climate that way. The ellipticity does alter the solar radiation reaching the Earth, and precession determines whether the NH or the SH hemispheres are warmer in summer. When all three cycles coincide to make the Northern Hemishere warm then an interglacial is the result.

    HTH,

    Cheers, Alastair.

    Comment by Alastair — 18 Sep 2011 @ 4:16 PM

  148. Hey Alistair,

    Long time no see/read… The Arctic Circle is an artifical line. A northern pole and a region within 30 degrees of that pole will remain. Hence, globally there is no change in surface insolation.

    Cheers!
    Dave

    Comment by L. David Cooke — 18 Sep 2011 @ 7:03 PM

  149. Hey Alistair,

    BTW, concur wrt progression, currently favoring the SH, and the eliptic. Scratch est. wrt eliptic variation of 3% of the orbit should point to roughly a 7 deg. K variation in ToA insolation potential. If the current ToA value is modified by ghg and wv, the added potential should be significant. Based on the pattern we should be near the warmest period? Suggesting minimum elipticality? The signatures in the land are pointing to this condition.

    I guess I am more interested in the change caused by the eliptical variation and the effect on the TSI in watts at the ToA, as opposed to the absolute temperature. Does the potental 3% elipictical mean that the TSI varies between 1367 and 1325w/m^2? If so one would think that the Earth would have to be a ice planet and very likely to fall into “snowball” territory. It would appear on the surface it is only the protection provided by ghg and wv that we do not freeze.

    Your thoughts…

    Cheers!
    Dave

    Comment by ldavidcooke — 19 Sep 2011 @ 1:48 AM

  150. Hi Dave,

    The Arctic circle is not artificial. It is the minimum latitude at which you can experience the midnight sun, for want of a better definition. As the obliquity increases the Arctic circle moves south, increasing the size of the Arctic ice cap. Actually it is more complicated than that, but I hope you get the general idea.

    Cheers, Alastair.

    Comment by Alastair — 19 Sep 2011 @ 1:53 AM

  151. Hey Alistair,

    Now you have confused me, if the obliquity changes from roughly 24 to 21 deg. over roughly 26ky, then how does the total range of the Arctic circle get larger?

    Given any sphere, regardless its axis of rotation, the angle of incidence from a point source does not change. The only real difference is the duration of exposure of a given point may change. Hence, if we are considering a min. of tilt approaching (currently decreasing towards 21 deg.) Then the duration for a fixed insolative exposure for any given point is decreasing. Yet as to it’s influence over the area of the Arctic Circle, in relation to GW has not changed. At best the 3 deg. change in the fixed tilt angle mainly involves a change in the location of the albedo enhancing surface and a possible difference in heating or warming/cooling inertia as land-sea exposures change.

    If the axis were to move towards a 90 deg. Obliquity or tidal locked condition would the character of change become less zonal (in relation to the solar plane)? With the primary difference being rather then roughly 1/6th of the planets surface having to endour a semi- annual day that it would change to 1/2 of the planet having a permenant day. If so how much of the incoming insolation on the Sol side would be distributed by the atmosphere? In short, I could see there being a marked effect with a fixed low angle of obliquity and/or diminished rotational velocity (Venus…?); but 3 deg.?

    Cheers!
    Dave

    Comment by ldavidcooke — 19 Sep 2011 @ 8:32 AM

  152. Hey All,

    The reason I do not regard obliquity very high is a roughly 4 degree variation should suggest a roughly 1.5% variation in rotational velocity (If my math is any good it would suggest, to me, with the current Eular estimated angular velocity of 1040mph at the equator, a 3 deg. difference in angular velocity should be approx. 15 mph, with the current value being roughly 10 mph slower then the fastest rotational rate, (21 deg. obliquity). If you have a value significantly different I am interested in discussing it.

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 19 Sep 2011 @ 9:57 AM

  153. #151,2–I feel a tad confused myself.

    Dave, surely if we were to approach 90 degree obliquity, the Arctic Circle (per Alastair’s definition) would converge toward the Equator–which would definitely count as an expansion!

    Comment by Kevin McKinney — 19 Sep 2011 @ 12:27 PM

  154. Re:153

    Hey Kevin,

    Sorry, I was talking in relation to the current global definition of the Arctic Circle. As to a change in direct insolation, over time for a specific location, yes, you and Alistair are correct. The global area receiving direct sunlight over a period of a day would be lower as the angle of obliquity increased. Even though the equtorial rotational velocity and the silloutte does not change.

    Alistair was helpful in letting me discover for myself the error of my thought. I appreciate the chance you are offering to clear that up,( without looking like I was desparately beating a dead horse). I think the point I was exploring was obliquity as a contributor to GW. Based on my rough estimate of the effect of 3 deg. I do not see obliquity a main contributor to Climate Change or Arctic warming.

    As a layman I would not be comfortable trying to calculate Euler rotational velocities and the difference that 3 deg. would make. But, my porportional est. of 1.5% may not be terribly accurate; however, as a factor contributing to CC I believe could at most vary temperature seasonality by roughly 2 weeks. Suggesting obliquity may slightly increase a more rapid seasonal temperature swing, I just do not see it likely to change the annual amount of temperature swing.

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 19 Sep 2011 @ 5:41 PM

  155. Re: 153

    Hey Kevin,

    Pardon the brain burp, the last post was accurate for the Solstice in a solar orbit with the rotational axis pointing towards the sun, at the equinox with the current equator facing the sun, with a 90 deg. obliquity, the distribution area of insolation would not be much different then if obliquity were 0 deg. The only time it would matter is in a tidal locked condition where there were no rotation or if the axis pointed parallel to an orbital tangent. Sorry, heady subject and I lost my logic track.

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 19 Sep 2011 @ 6:27 PM

  156. I had a friend who didn’t believe in global warming until she worked in Alaska and saw the melt first hand. She also saw the breeding of grizzlies and polar bears that never used to share the same territory but are forced to because of melting ice.

    Comment by Dani — 20 Sep 2011 @ 9:46 AM

  157. Why is David Cooke’s rambling mess of denial allowed to be posted here?

    http://www.ozclimatesense.com/2010/11/more-psychobabble-about-why-skeptics.html
    “David Cooke said… Well, there are many links between the bogus science of global warming and the bogus science of psychology.

    Both of these cons depend on weasel words, appeal to authority, misleading statistics and plain simple bluff. And both make ad hominem attacks on their critics.
    November 19, 2010 8:39 AM ”

    Note to David: Calling someone out for being dishonest is not an ad hominem attack. Your clear bias, as opposed to the feigned collegiality here, is betrayed by the quote above in which you say climate science is “bogus” a “con” and liken climate science discussion to weasel words, etc.

    I see no reason why the scientists here should allow posts from someone with such great disrespect for your work and who is inherently dishonest in his communication.

    Comment by ccpo — 22 Sep 2011 @ 9:09 AM

  158. RE:157

    Hey ccpo,

    Likely because your “quote” was not mine.

    If you are really interested and am concerned over the basis of my bias, try researching ldavidcooke such as a moderator for climate and earth sciences at UK Weather World. That Dr. Schmidt and company has been gracious to allow me to share my observations and questions here has been very welcome. As of yet it is clear there is a lot of work ahead and attacking folks without trying to understand or point out errors in their thoughts is unproductive, IMHO.

    If you disagree with the observations I make or can clear up where I have posed questions you are welcome to post at the UKww climate forums; however, as this conversation began here, it would be more appropriate to either continue this discussion here, or to take it off line. Either way is fine…

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 22 Sep 2011 @ 11:15 AM

  159. I’m fairly confident you are one and the same, but it doesn’t really matter. You question here basic elements of climate science and it is time to stop coddling such either inept understanding or intentional obfuscation. Well past time. I don’t care what flavor of denial you employ; I identified them all years ago and have watched the various waves of repackaged denial break on the shores of science.

    I addressed your issues some time back. I see no need to do so again. It’s not the sun, and that is conclusive. It’s not anything (the primary driver, i.e) than GHGs. Period. This is obvious and unambiguous, so your pretense at polite “Gosh!”-ism does not impress.

    Anywho… I should have put this in Variations, so will drop it now.

    Comment by ccpo — 22 Sep 2011 @ 4:32 PM

  160. Hey ccpo,

    Clearly you have made another error in I also did not say that the sun or input at the Top of the Atmosphere is the issue. What I did say was that changes within the lower atmosphere are changing both the average wideband insolation and weather patterns.

    It is likely these changes that are driving an increase in surface daily high air temperatures. In addition, there appears to be a reduction in surface relative humidity. This reduction in RH nor soil moisture are directly related to a increase in GHG radiant energy. Though I clearly agree that natural variation can be pushed by GHG.

    At issue in my lack of understanding is how can an increase of 135ppm of CO2 fully mixed at an average altitude of 500mb demonstrate an effect that is only visable in the paleo or fossil records at about a 1500 or 1250ppm above the current CO2 level? It is unlikely that by its self the influence of 135ppm of CO2 is as dramatic as the changes of recent note.

    Now if you are intetested in exploring or are interested in teaching I believe we might be able to have a wondeful conversation. If not then fine, though it makes me wonder at your purpose here.

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 22 Sep 2011 @ 5:40 PM

  161. Well == http://www.topix.com/member/profile/ldavidcooke is pretty definitely opinionated about whether CO2 can have any effect, he thinks it not likely.
    Would that be the same guy?

    Comment by Hank Roberts — 23 Sep 2011 @ 1:09 AM

  162. Re:161

    Hey Hank,

    Yes, this is the same person and the ideas posted pretty much matched my understanding of the Science at the time. As was the person on the Yahoo Climate Discussion Boards that refuted that the influence of GHGs on the GAT between 2000 and 2005 that was the claimed to be 3.5 deg. F. As is currently a moderator at UKww for Climate and Earth Sciences.

    As to the value of influence of GHGs on the GAT, I believe I am aware of the work to date wrt TSI and the radiational imbalance. As to the influence, Dr. Hansen and company did an excellent job of estimating the added input in watts that can be assocated with the retention of the 15um energy. It s not much different then a little more then 1/2 the value of the change in watts of the full spectrum between the solar min.-max. Though the solar max. Variation is distributed between 80-90% of the sillouette of the Earth whereas CO2 covers about 90% of the globe all the time and not just every 11 yrs.

    To me this would suggest that the influence of GHGs alone should be a little bit more then Sol at Max. Suggesting that weather anomolies observed during the solar maximum, pre-1950, would become the new normal, with the solar max. nearly doubling that influence.

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 23 Sep 2011 @ 1:47 PM

  163. David, you are talking nonsense.

    “At issue in my lack of understanding is how can an increase of 135ppm of CO2 fully mixed at an average altitude of 500mb demonstrate an effect that is only visable in the paleo or fossil records at about a 1500 or 1250ppm above the current CO2 level?”

    Assuming your framing is correct, go read the literature and you’ll know. Hint: it’s not JUST CO2. I already told you this has been covered here at RC, so you don’t have to go far to find the answers.

    Comment by ccpo — 23 Sep 2011 @ 5:40 PM

  164. Hey ccpo,

    Thanks, though I am aware of the participants in the AR4. The confidence in some were low and of late I have not seen any measures that have improved their values. Of course I am limited to popular periodicals such as the NASA News, “Science Daily” and “Science News”. Oh and the critical reviews here.

    I believe there was a big push a couple of years ago in relation to some modeling work that Dr. Schmidt and the team were working on with NCAR though I have not seen anything further. I suspect the committiees and contributors are still waiting on the next report before unveiling the latest advancements. About the biggest change over the last three years was a reference that Hank made in relation to or a study of how the AR4 participants are being manifest or incorporated into the weather patterns and circulations, atmospherically speaking.

    Are you aware of recent any recent advances you can point out? It certainly helps me get things straight when the logic and information fit together. Otherwise I am left to my own devices and we see where that takes me.

    (Oh, btw a quick question where do you get the impression I am trying to add something new, when it is clear that is unlikely as I have neither the resources or capabilities? I am only reguratating what is present in the popular press and looking at how the data ties into my understanding of it.)

    Cheers!
    Dave Cooke

    Comment by ldavidcooke — 23 Sep 2011 @ 11:57 PM

  165. There are plenty of websites that encourage regurgitating what is in the popular press, and the Open Thread at RC collects that stuff too.

    — this isn’t that —-

    Let’s talk about science — articles in published science journals, eh?

    Here’s a new article relevant to THIS topic
    The authors’ names will be familiar:

    http://www.agu.org/pubs/crossref/2011/2011GL048807.shtml

    Influence of initial conditions and climate forcing on predicting Arctic sea ice

    Blanchard-Wrigglesworth, E., C. M. Bitz, and M. M. Holland
    Geophys. Res. Lett., 38, L18503, doi:10.1029/2011GL048807
    Publication Date: 21 September 2011
    5 pages, 3 figures, 1 table
    .
    ..

    ….
    …..
    Did you read it?

    Comment by Hank Roberts — 24 Sep 2011 @ 10:01 AM

  166. Hey Hank,

    Concur, each of the following are backed by science and none, to my knowledge, by obvious deniers.

    http://www.sciencedaily.com/releases/2007/03/070323134845.htm
    http://www.sciencedaily.com/releases/2008/08/080822102344.htm
    http://www.sciencedaily.com/releases/2011/02/110225122914.htm
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1913777/
    http://www.sciencedaily.com/releases/2009/08/090806141716.htm
    http://www.sciencedaily.com/releases/2010/04/100415085344.htm

    At best your link discusses the durability of ice based on volume, latent heat and energy added. The question seems to keep returning to the added energy coefficient. Changes in natural variations seem to adjust around environmental changes to a degree. Currently, we are just discovering the biologic response to environmental changes. We continue to discover the systemic thermodynamic responses to environmental changes. Where do you want to take the discussion next?

    Cheers!
    Dave

    Comment by ldavidcooke — 25 Sep 2011 @ 1:12 PM

  167. Dr. Notz wrote in the main post above:

    “… we scientists have failed to make sufficiently clear that a major loss of sea ice during the early summer months is climatologically more important than a record minimum in September….”

    And the increasingly early change from ice to open water changes almost everything else, not just the albedo:

    http://scholar.google.com/scholar?hl=en&q=Global+Change+Biology+spring+plankton+bloom&as_sdt=0%2C5&as_ylo=2011&as_vis=0

    results include these titles:

    Climate change and the phytoplankton spring bloom: warming and overwintering zooplankton have similar effects on phytoplankton
    U Sommer… – Global Change Biology, 2011 – Wiley Online Library

    Competitive dynamics in two species of marine phytoplankton under non-equilibrium conditions
    int-res.com P Cermeño, JB Lee, K Wyman, O Schofield… – Mar Ecol Prog, 2011

    Stoichiometric effects of warming on herbivore growth: experimental test with plankters
    W Makino, Q Gong… – Ecosphere, 2011 – Eco Soc America
    although the onset of the spring phytoplankton bloom occurs earlier along with warming, it is documented that … Water temperature and stratification depth independently shift cardinal events during plankton spring succession. Global Change Biology 16:1954–1965 …

    ========
    So as with other areas, there’s a physical change and a direct forcing, and then there’s feedbacks

    Comment by Hank Roberts — 25 Sep 2011 @ 7:02 PM

  168. Hey Hank,

    The degrees of freedom wrt gross population differences based on starting populations appear broad, then again it depends on the conditions specifed in the referenced docs. Following the chain may be useful or it may be a wild goose.

    Personally, it would be nice if a synoposis of initial state, change of state and terminal state would be useful to non-professionals in that specific field; but, that is not the way of most papers. Hence, without several days jogging it will be hard to determine the energy spectrum and intensity, dissolved O2/CO2/NO/SO/FeO/Ca/NaCl/…or initial conditions, as it is, the end or change in conditions did not appear either, hence it would appear difficult to duplicate the experiment.

    Cheers!
    Dave

    Comment by ldavidcooke — 25 Sep 2011 @ 10:01 PM

  169. @266 Why post a bunch of links to an issue completely unrelated to melting Arctic Sea Ice?

    Rhetorical question.

    At best your link discusses the durability of ice based on volume, latent heat and energy added.

    Discusses the issues. How absurd!

    The question seems to keep returning to the added energy coefficient.

    Uh, the amount of energy added is the point. How keen of you.

    Changes in natural variations seem to adjust around environmental changes to a degree.

    Changes are affected by changes. What would we do without you, David?

    Currently, we are just discovering the biologic response to environmental changes.

    “Just?” Yeah… we haven’t known that changing ecosystems affect the biota in those ecosystems… just figuring that out. Yup. Let’s not do anything!

    We continue to discover the systemic thermodynamic responses to environmental changes.

    Yup. Good thing we understand them so well already that we can actually make educated models of what is coming.

    Where do you want to take the discussion next?

    With you? Nowhere. It’s pointless. You are not looking for answers, you are propagandizing.

    Comment by ccpo — 26 Sep 2011 @ 12:28 PM

  170. Hey cppo,

    Actually, we are attempting to advance the store of knowledge and you…

    Cheers!
    Dave Cooke

    Comment by L. David Cooke — 26 Sep 2011 @ 2:49 PM

  171. No, David, you aren’t. You have argued points as if contentious that are not. You have presented ideas already scientifically invalidated as valid. You have claimed chicanery where none exists while failing to address the chicanery perpetrated by people spouting the same falsehoods you do, already well documented.

    To claim goodness is not to be good. To be good, one must do good. You are not doing good.

    Comment by ccpo — 1 Oct 2011 @ 11:32 AM

  172. The adiabatic nature of current arctic air is quite strong, the onset of
    dominant inversion driven lower atmosphere appears quite delayed. I credit the wider open seas for this. The re-freeze seems weakened or sluggish What I expect is any big wind will show this, current forecast for Fram strait calls for strong winds. We shall see how consolidated the pack is soon.

    Comment by wayne davidson — 3 Oct 2011 @ 9:56 PM

Sorry, the comment form is closed at this time.

Close this window.

0.571 Powered by WordPress