Ice cap scare – just 67 millennia left

Inside the Greenland ice cap

Yes, that’s right, only 67,000 years to go.

David Biello wrote an unlovely piece of non-science a few days ago which Scientific American was happy to publish.

It seems the once-reliable journal doesn’t care about standards now. The headline was uncompromising: Greenland Meltdown Driven by Collapse of Glaciers at Ocean Outlets.

To call what follows a “meltdown” is a hoax, a fraud, a betrayal, a cheat, a perfidy, a sham and a swindle. Not to mention several dozen other words in the thesaurus which all mean deceit.

The subheading gives voice to the first prevarication: The interactions between the island’s glaciers and the surrounding seas may be driving ice loss, according to aerial photographs.

Global weirding

But the opening paragraph got down to brass tacks: “the ice sheet as a whole has lost some 36 billion metric tons of ice each year in recent years.” We shall look at what that means. First, though, consider the next comment: “Thanks to weird weather, nearly the entire ice-covered surface of the world’s largest island melted for a period this year.”

The word “weather” is a hyperlink, as though they have some scientific explanation of weird weather, but they mislead us again. You end up on a general weather page that doesn’t mention weird weather. I’ve learned that the strange melting episode affected only the very surface of the ice cap, which re-froze within hours. The melt was caused by a warm weather system which is not unusual – it occurs about every 150 years.

But “global weirding” is the new codeword for global warming, and it’s applied to any slightly unusual weather event. Try it yourself the next time it rains when you hoped for sun, or fog appears just when you wanted rain. Call it global weirding and notice how people listen to you. Magic!

But it is shrinking

Anyway, this slight mid-summer melting is not because of anything we’ve done and there is no need for alarm.

But the ice cap has lost about 36 billion metric tons of ice a year recently. It sounds a lot, but let’s put it into perspective. The first question in my mind is: how does the loss compare to the mass of the whole ice cap? It’s easy to find out.

Wikipedia tells us that the volume of the Greenland ice cap is 2,850,000 cubic kilometres, or 2.85 × 106 km3. It gives values for the density of glacial ice from which I chose 850 kg/m3 (less than liquid water at 1000 kg/m3. Finally, there are 109 cubic metres in one cubic kilometre.

Caution: raw maths ahead

So:
Density of one cubic km of ice cap = 850 × 109 kg/km3
Total ice cap volume = 2.85 × 106 km3
Multiply = 2.42 × 1018 kg
Convert to tonnes = 2.42 × 1015 T
Or 2420 trillion tonnes.

It’s currently losing 36 billion tonnes per year.

Or, a 2,420,000,000,000,000 kg ice cap is losing 36,000,000,000 kg per year.
I calculate that to be an annual loss of 0.00148% of the ice cap.
That’s not very much at all, Winifred. Quite trivial, in fact.

How long will the ice last?

Correct me if I’m wrong, but it seems that at that rate there are only 67,222 years of ice cap left.

67,222 years

Oh dear. I wonder if we could get the mainstream media to publish this alarming news?

Possibly not.

What if we just mentioned that it’s melting, without pointing out how slowly?

They’d probably fall for it – their reporters don’t know any maths.

97 Thoughts on “Ice cap scare – just 67 millennia left

  1. Nic the NZer on August 7, 2012 at 12:39 am said:

    Wow, that article has to be read to be believed, or maybe I should say you shouldn’t believe everything you read. Especially when it uses such alarming demagoguery. Maybe we should call the magazine ‘Fearmongering American’ from now on?

  2. Simon on August 7, 2012 at 9:17 am said:

    That is an extremely fast rate of melting in geological terms. To put things in perspective, Homo sapiens have been around for over 60,000 years.

  3. Are we not likely to be in the next ice age when this figure rolls around?

  4. Still too slow, Simon. You see, the alarmists are demanding we stop it immediately because it’s our fault. Do you think we can? Do you think it is? I think it’s a scare story. There’s no way we can melt 2420 trillion tonnes of ice with our puny smokestacks and exhausts.

  5. Yes, and that’s the other thing. Survival is likely to be on our mind very strongly and it’s doubtful we would care if a piece of the damnable ice was melting. Melt it all, we’d say.

  6. Richard C (NZ) on August 7, 2012 at 11:20 am said:

    Greenland Ice Melt every 150 years is ‘right on time’

    http://wattsupwiththat.com/2012/07/24/greenland-ice-melt-every-150-years-is-right-on-time/

    Study Predicts Slowdown, Halt in Greenland Ice Melting

    http://www.voanews.com/content/study_predicts_slowdown_halt_in_greenland_ice_melting/1454091.html

    Someone switch off that dang meltdown alarm.

  7. Jim Mck on August 7, 2012 at 2:31 pm said:

    Hi Richard,

    “the ice sheet as a whole has lost some 36 billion metric tons of ice each year in recent years.”

    The naturally inquiring mind naturally asks the question you have asked – is that a significant amount and should I be worried? Unfortunately most people take it as presented and propoganda does work, at least for a period of time.

    Perhaps we could come up with a few of our own alarmist one liners.

    “Rio cost more than the GDP of 15 poorest nations”
    “More scientific research funding being diverted into junkets”

  8. here’s one –
    The UK annual contributions to the EU could fund two Olympic games per year

  9. Hi Richard T,
    Richard C is likely to take you to task for fitting a linear trend to what appears to be a clearly accelerating ice loss. He is generally quite passionate about the subject.

    Had you considered including the acceleration of the ice melt in your calculation? The acceleration is quite pronounced and gives a very different result. You might also want to consider converting it into meters of sea level rise by 2100 to put it into perspective.

    One estimate of the rate of acceleration of ice loss in Greenland is −22 ± 4 Gt/yr2 from Schrama, E. J. O., and B. Wouters (2011), Revisiting Greenland ice sheet mass loss observed by GRACE

    http://www.agu.org/pubs/crossref/2011/2009JB006847.shtml

    I’ll have a go at the calculation myself in the next couple of days so don’t panic if you don’t have time to look at it yourself but I would appreciate a independent check.

  10. Heh, heh!

    Richard C is likely to take you to task for fitting a linear trend to what appears to be a clearly accelerating ice loss.

    Since I haven’t even provided a graph, much less a linear trend, I must assume you’re referring jocularly to my calculation of how long the ice will last. Ha, ha.

    The authors say the rapid melting that has made headlines in recent weeks also is likely to slow or stop. Their conclusion also contradicts widely-reported predictions that the accelerating ice melt will trigger a significant rise in global sea levels.

    My calculations provided some perspective for the recent annual loss, not a prediction, and acceleration wasn’t considered. There was no mention in the abstract of an acceleration. In fact, that’s right, the study was reporting the opposite: a slowdown in melting with perhaps a halt to come.

    The paper you cited shows similar ice loss, at about 36 Gt/yr, but shows mass loss increasing in some areas and decreasing in others, causing doubt about the future.

    I’d appreciate an independent check of my figures, too, so help yourself.

    I don’t know how to reconcile the differences between these papers.

  11. Richard C (NZ) on August 8, 2012 at 10:27 am said:

    Relax Nick, no need to get into serious speculative extrapolation.

    Study Predicts Slowdown, Halt in Greenland Ice Melting

    http://www.voanews.com/content/study_predicts_slowdown_halt_in_greenland_ice_melting/1454091.html

    And it’s cyclical, keep an eye out around 2150

    http://wattsupwiththat.com/2012/07/24/greenland-ice-melt-every-150-years-is-right-on-time/

  12. Richard C (NZ) on August 8, 2012 at 2:06 pm said:

    The Hockey Schtick has featured the above post

    Greenland meltdown could happen in only 67,000 years!

    http://hockeyschtick.blogspot.co.nz/2012/08/greenland-meltdown-could-happen-in-only.html

  13. Cool! Thanks, RC.

  14. Simon on August 8, 2012 at 2:39 pm said:

    Which all goes to show how a crude back of the envelope estimate suddenly becomes a “fact”. Given that ice loss appears to be accelerating (2002:137Gt, 2009: 286Gt, 2012: 430Gt) it seems likely that collapse of the Greenland ice sheet will happen far faster than that. If you want to be really concerned, read http://www.the-cryosphere-discuss.net/4/233/2010/tcd-4-233-2010.html

  15. Simon, remember that it was SciAm who claimed 36 Gt annual ice loss, it was SciAm who described it as a “meltdown” and it was SciAm who failed to mention the paper said the melting was slowing down and might stop. I don’t claim the 36 Gt is correct and only use it to examine what SciAm said.

    I disagree with you: it’s not clear that ice loss is accelerating.

    In the paper you cite, I lack the ability to understand the modelling details. But I would urge caution in assessing any conclusions from modelling, any assumptions based on the warming potential of CO2 (this paper’s riddled with it) and any conclusions substantially at variance with observation. For example, this calculates that the ice sheet is 33% larger in volume than observation shows us.

    So, again, acceleration is not a bit clear.

  16. Richard C (NZ) on August 8, 2012 at 3:41 pm said:

    “Given that ice loss appears to be accelerating (2002:137Gt, 2009: 286Gt, 2012: 430Gt) ”

    “Appears” to you Simon but there are those that disagree e.g. Kurt H. Kjær says:

    “Our results show that the thinning of the ice sheet at the end of the 80’s and beginning of the 90’s eased over a 4-8 year period, after which a period of stability occurred until 2003. Our conclusion is therefore, that if we judged against longer periods of time, the current thinning of the ice sheet is likely to ease within an 8-year period.”

    http://news.ku.dk/all_news/2012/2012.8/Aerial-photos-reveal-dynamic-ice-sheet/

    Or are you denying that disagreement?

  17. Simon on August 8, 2012 at 4:28 pm said:

    No, the degree of acceleration is a moot point. What everyone agrees on though is that the Greenland ice sheet is decreasing over time. It is a good indicator of climate change and the introduction of large volumes of cold water into the northern ocean could cause problems in the future.

  18. eryone agrees on though is that the Greenland ice sheet is decreasing over time. It is a good indicator of climate change

    which means what, exactly?

  19. Richard C (NZ) on August 8, 2012 at 4:48 pm said:

    “What everyone agrees on though is that the Greenland ice sheet is decreasing over time”

    Sort of.

    What Kurt Kjær, Shfaqat Abbas Khan and Kristian K. Kjeldsen are saying is that the recent observations are merely part of a cycle (nothing extraordinary) and that they predict a return to a benign regime in due course.

    “It is a good indicator of climate change and the introduction of large volumes of cold water into the northern ocean could cause problems in the future”

    Rubbish.

    It is a good indicator of a natural cycle taking place and the introduction of large volumes of cold water into the northern ocean has all the effect it will have right now in the present.

  20. Simon on August 8, 2012 at 5:00 pm said:

    Please read the first sentence of your reference: ‘Describing the findings, University of Copenhagen Associate Professor Kurt H. Kjær at Professor Eske Willerslevs Centre for GeoGenetics at the Natural History Museum of Denmark asserts: “That air temperatures have increased and melting has intensified is relatively well-understood.”‘

  21. Richard C (NZ) on August 8, 2012 at 5:16 pm said:

    “Which all goes to show how a crude back of the envelope estimate suddenly becomes a “fact”.”

    That could be said of ALL IPCC projections.

    A guess at the future using a sophisticated supercomputer and programming is still a guess but an IPCC guess “suddenly becomes a “fact”” too – and we are paying for that “fact” by carbon taxes.

    In the IPCC climate case, a crude guess is given the illusion of a sophisticated.guess by the implementation and duplication of some very expensive technology. Policymakers just would not have been impressed by back-of-the-envelope guesses, instead they’ve been fooled by an illusion of ordinary every day guesses masquerading as sophisticated science.

    Guesses made fallacious by circular reasoning and the adoption by climate science of a “contemporary” feedback system in preference to the classical of physiology, electronics and nature itself. The “contemporary” feedback system is diagrammed here:

    http://jonova.s3.amazonaws.com/guest/evans-david/climate-models-feedbacks-600.gif

    Not only has the water vapour amplification been proven NOT to exist but “contemporary” climate science has reversed the sign of the classical negative water vapour feedback to positive, fooling themselves and subsequently policymakers in the process.

  22. Richard C (NZ) on August 8, 2012 at 5:20 pm said:

    For a short time Simon – it’s cyclic.

    Kjær:-

    “Our conclusion is therefore, that if we judged against longer periods of time, the current thinning of the ice sheet is likely to ease within an 8-year period.”

  23. Simon on August 8, 2012 at 6:04 pm said:

    Of course it’s cyclic; Greenland is heavily influenced by the North Atlantic Oscillation. But around that cycle there is a warming trend: http://www.meltfactor.org/blog/?p=677

  24. Richard C (NZ) on August 8, 2012 at 6:45 pm said:

    “Of course it’s cyclic”

    Thank you Simon.

    It’ll be back circa 2140 but we wont be debating it.

  25. It’s quite interesting to hear different perspectives on the amount and progress of the warming, though, as everyone knows, the only reason we’re discussing it is because we’re trying to stop the warming because we think it will become dangerous.

    But we cannot do that if we don’t know the cause of the warming. What is it?

  26. Richard C (NZ) on August 8, 2012 at 8:08 pm said:

    “But we cannot do that if we don’t know the cause of the warming. What is it?”

    One factor must be aerosols and insolation because that’s been the partial attribution for cooling in the Box post that Simon links to:-

    20th Century cooling period

    During the ~63 year period (1930 to 1992) cooling prevailed that can be attributed partially to an increases in atmospheric aerosols that reduce surface insolation. Liepert et al (2002) estimated that there a global reduction of about 4% in solar radiation reaching the ground between 1961 and 1990.

    Re the warming, Box says:-

    The post-1994 warming, is attributable to:

    1.) a growing absence of sulfate cooling because there has not been a major volcanic eruption since at Mount Pintubo in 1991;

    2) a reversal of the global dimming trend (Wild et al. 2009); and

    3) ongoing and intensifying anthropogenic global warming (AWG) owing to a dominance of enhanced greenhouse effect despite various anthropogenic cooling factors such as aerosols and contrails (IPCC, 2007)

    Apparently the “bad” CO2 of 3) is only in the Arctic because the 1995 – 2010 warming in Box’s plot here http://bprc.osu.edu/mediawiki/images/9/97/Greenland_summer_air_T_update_to_Box_et_al_2009.png

    Is not evident in the tropics, SH or NH extratropics satellite record here http://www.appinsys.com/GlobalWarming/GW_NotGlobal_files/image010.jpg

  27. Richard C (NZ) on August 8, 2012 at 8:37 pm said:

    And here’s the big knowledge gap,

    Box:-

    “The cooling phase has also been attributed to the Atlantic Multidecadal Oscillation (AMO) (e.g. Schesinger et al. 1994). Though, it remains unclear whether AMO is a recurrent harmonic oscillation or just a hiatus of warming caused by sulphate cooling”

    So here we have a major natural variation but its effect is “unclear”.

    No similar uncertainty by Box though about the “…ongoing and intensifying anthropogenic global warming (AWG) owing to a dominance of enhanced greenhouse effect”.

    That’s the same “enhanced greenhouse effect” that John Christy shows is present in the CMIP5 model simulations for AR5 but not in reality.

    http://curryja.files.wordpress.com/2012/07/christy-fig.jpg?w=808&h=622

  28. Richard C (NZ) on August 8, 2012 at 8:55 pm said:

    And here’s the little problem for aCO2 attribution in the Arctic.

    Barrow Alaska CO2 concentrations

    http://cdiac.ornl.gov/trends/co2/graphics/Barrow_CO2.jpg

    Look nothing like Summer Arctic Tsfc from 1974 onwards

    http://bprc.osu.edu/mediawiki/images/9/97/Greenland_summer_air_T_update_to_Box_et_al_2009.png

  29. Richard C (NZ) on August 8, 2012 at 9:28 pm said:

    And Barrow CO2 1974 – 2007 increased identically to Mauna Loa over the same period.

    Barrow 50 ppmv

    http://cdiac.ornl.gov/trends/co2/graphics/Barrow_CO2.jpg

    Mauna Loa 50 ppmv

    http://www.esrl.noaa.gov/gmd/ccgg/trends/

    So why didn’t Tropics and Arctic temperatures rise in concert if CO2 is the driver (they didn’t in the satellite record)?

    Hadley CRUG Arctic vs CO2 shows no correlation.especially the regime change around 1915.

    http://junksciencearchive.com/MSU_Temps/Arctic75Nan.png

    I think we can conclude that CO2 is not the Arctic driver.

  30. The Poms are now blaming Greenland ice melting for shifting the jet stream and stuffing up their summer 🙂
    http://www.guardian.co.uk/science/2012/aug/08/shape-of-british-summers-to-come

  31. Richard C (NZ) on August 9, 2012 at 11:49 am said:

    Until they can get their 3 month forecast right there’s not much to be taken from UK Met predictions.

    British supercomputer botches weather forecasts

    Written by Jonathan DuHamel, Tucson Citizen | June 27 2012

    https://www.climateconversation.org.nz/open-threads/climate/meteorology-001/

    We haven’t forgotten their “barbeque summer” or the wettest drought ever.

  32. Hi all, there seems to be a bit of confusion here due to the fact that the Kjaer paper refers only to the Northwestern ice sheet so it is perfectly possible that the ice loss has slowed on the Northwestern ice sheet while the accelerating loss shown by the satellite data continues over the whole of Greenland.

    Has anyone found a full text version of the Kjaer paper? I’m not comfortable drawing any particular conclusions from it based on only the abstract or various media interpretations of it.

    As for the surface melting event that covers the entire Greenland ice sheet it is certainly not unprecedented but it does not happen periodically every 150 years.

    http://www.igsoc.org/annals.old/21/igs_annals_vol21_year1995_pg64-70.pdf

    See fig 1.

    The 150 figure is the average over the past 10,000 years which includes a much higher frequency in the distant past (when summer insolation was higher). The average period over the last 3,000 years is more like 250 making this event unusual.

    The paper also shows that 3 melt events in 100 years would be unprecedented in the last 5000 years and five events within 100 years would be unrepresented in the whole 10,000 year record.

    So while you might write this event off as a freak event, if it happens a couple more times before 2112 that if would be serious cause for concern.

    Btw if the current rate of accelerating ice loss over the whole of the Greenland ice sheet continues by 2100 we would be losing 2232Gt/y of ice per year and the sea level would have risen by approx 30cm (not accounting for thermal expansion or the effect of other ice sheets).

    Please note that this is in no way a prediction. I merely wish to illustrate the difference between linear rates of ice loss that Richard T characterised and the accelerating loss which we are currently seeing.

  33. Richard C (NZ) on August 11, 2012 at 9:04 am said:

    Meanwhile:-

    New paper finds sea level rise has greatly decelerated over past 10 years

    http://hockeyschtick.blogspot.co.nz/2012/08/new-paper-finds-sea-level-rise-has.html

    Boretti, A.A. 2012. Short term comparison of climate model predictions and satellite altimeter measurements of sea levels. Coastal Engineering 60: 319-322.

    The Australian scientist reports that the average rate of SLR over the almost 20-year period of satellite radar altimeter observations is 3.1640 mm/year, which if held steady over a century would yield a mean global SLR of 31.64 cm, which is just a little above the low-end projection of the IPCC for the year 2100. However, he also finds that the rate of SLR is reducing over the measurement period at a rate of -0.11637 mm/year2, and that this deceleration is also “reducing” at a rate of -0.078792 mm/year3.

  34. Richard C (NZ) on August 11, 2012 at 9:54 am said:

    That is, you can speculate all you like Nick (as the IPCC does) but first you have to explain why your “serious cause for concern” (a supposed accelerating Greenland ice melt) is having the result of a decelerating SLR.

    It will be interesting to see what IPCC AR4 makes of Boretti 2012 (if it even makes it).

  35. Well a 5 – 10 year trend is hardly convincing. There are numerious effects that will distort the signal over such short time frames. Once again if you have a link to to the full paper that would be helpful so we can see if the have allowed for the inverse barometer effect etc. I prefer not to rely on someone else’s interpretation.

    In any case I’m not sure why you would expect to see the effect of Greenland’s accelerated melting in global sea level rise when Richard T has already shown that the current level of melting is not adding a huge amount to global sea levels.

    If the accelerated melting continues in Greenland by the end of the century it will be a different story. I would have thought it would be wise to focus on leading indicators (such as accelerating ice sheet loss) rather than waiting until accelerating sea level rise is locked in before admitting that maybe we have a problem.

  36. Richard C (NZ) on August 11, 2012 at 1:43 pm said:

    “There are numerous effects that will distort the signal over such short time frames”

    Great, what are they?

    Enough time has elapsed for your “leading indicator” to produce an effect in SLR but instead we see the opposite.

    You seem intent Nick, on perpetuating an alarm scenario as if your career and reputation depend on it.

    Do they?

  37. Richard C (NZ) on August 11, 2012 at 1:54 pm said:

    “Well a 5 – 10 year trend is hardly convincing”

    The trend is over the entire 18 year satellite record.

  38. Richard C (NZ) on August 11, 2012 at 2:21 pm said:

    Here’s the trends http://www.nipccreport.org/articles/2012/aug/boretti2012b.jpg

    The 3rd order polynomial has an R squared value closest to 1 (0.94967) and is therefore a better representation of the data than is the 2nd order (0.9412) or 1st order (0.93377)

    Just corroborates my own TOPEX/Poseidon/Jason-1/2 trend analysis that I’ve provided for you previously Nick so this shouldn’t be news i.e. anyone can do it, just that Boretti has now formalized it in the peer-reviewed literature.

  39. Hi Richard,
    This is just a personal interest, I am just trying to present facts and avoid confirmation bias by discussing them with people who hold an opposing opinion. Sorry if you find it alarming.

    I’m not really sure what your point is. Are you claiming that Greenland isn’t melting? That it is but the rate is not accelerating? Or that melting ice sheets do not contribute to sea level rise? Could you please clarify what you are trying to say?

  40. Richard C (NZ) on August 11, 2012 at 9:06 pm said:

    “Are you claiming that Greenland isn’t melting?”

    No but that it’s cyclical (as your brother-in-arms Simon agrees up-thread)

    “That it is but the rate is not accelerating?”

    It’s cyclical so there will be occasions when it’s in states of acceleration, deceleration or inflexion i.e. phases.

    “Or that melting ice sheets do not contribute to sea level rise?”

    Currently, SLR is decelerating (Boretti 2012) – I hope you’re not denying this peer-reviewed paper Nick), therefore current ice melt is ineffectual as an agent of SLR over the last decade or so

    Any extrapolation (projection) of SLR must be along Boretti’s 3rd order polynomial (statistically) which actually reduces SLR concern from a benign normal rather than elevates it to anything extraordinary.

    That is until such time as SLR exhibits something other than Boretti’s trend – that may take another 18 years to ascertain.

     

    REPLY: RC, you work incredibly hard to contribute here, so please stop poking people. (“I hope you’re not denying this peer-reviewed paper Nick) There’s no need — the research you do is enough, man! – Richard T.

  41. Richard,
    Do you really believe that there is a significant difference between an R² of 0.94967 and 0.9412? Extrapolation of multiple order polynomials can lead to extremely misleading results.

  42. Hi Richard C,
    Thanks for the clarification. I’m glad to see we agree that Greenland is melting at an accelerating rate. Obviously we disagree about what is likely to happen in the future.

    I suspect that melting will continue to accelerate due to warmer seas at least until the ocean terminating glaciers retreat onto land. It is not yet clear to me what the effect of increasing albedo will have but it is possible that this will become the dominate driver of melt and it is not obvious what the results of this will be.

    On the other hand you believe that the current accelerating melt in Greenland is cyclic and that it will reverse at some point. Could you please discuss some of the evidence that has led you to this conclusion? Perhaps you could start by telling me what you think is causing the current melting and why this driver is about to reverse?

  43. Richard C (NZ) on August 12, 2012 at 10:03 am said:

    “I’m glad to see we agree that Greenland is melting at an accelerating rate”

    That’s not what I said Nick, my response was:-

    “It’s cyclical so there will be occasions when it’s in states of acceleration, deceleration or inflexion i.e. phases”

    Greenland ice conditions are in a cyclical phase, what will happen in the next decade is speculation by everyone because no-one really knows but there’s no alarm anyway. Speculation about what will happen in 2100 is plainly a matter of opinion – not science.

    I don’t see any point in further discussion if:-

    A) Greenland ice melt is currently not an agent of SLR (because SLR is decelerating – no alarm)

    B) There’s no anthro cause for atmospheric conditions in the Arctic as can be seen from the temp – CO2 comparisons up-thread.

    C) Greenland sea temperatures are cyclic too and influenced by the North Atlantic Oscillation (NAO) but the effects are complex. These guys take 55 pages to explain them:-

    The Ocean’s Response to North Atlantic Oscillation Variability

    http://rainbow.ldeo.columbia.edu/papers/ocean_chapter-5.pdf

    Basically though, NOAA CPC says:-

    Strong positive phases of the NAO tend to be associated with above-averagel temperatures in the eastern United States and across northern Europe and below-average temperatures in Greenland and oftentimes across southern Europe and the Middle East. They are also associated with above-average precipitation over northern Europe and Scandinavia in winter, and below-average precipitation over southern and central Europe. Opposite patterns of temperature and precipitation anomalies are typically observed during strong negative phases of the NAO. During particularly prolonged periods dominated by one particular phase of the NAO, anomalous height and temperature patterns are also often seen extending well into central Russia and north-central Siberia.

    http://www.cpc.ncep.noaa.gov/data/teledoc/nao_ts.shtml

    Strong positive NAO => below-average temperatures in Greenland

    Strong negative NAO => above-average temperatures in Greenland

    But the melt is on a much longer cycle (about 153 years) than is the NAO which is short duration and varying wildly.

    http://www.cpc.ncep.noaa.gov/data/teledoc/nao.timeseries.gif

    Scafetta details cycles in his 2010 paper:-

    Empirical evidence for a celestial origin of the climate oscillations

    http://www.fel.duke.edu/~scafetta/pdf/scafetta-JSTP2.pdf

    I don’t see a 153 year cycle but “multiple mechanisms” are probably the key, quoting the Conclusion:-

    The results herein found show that the climate oscillations are
    driven by multiple astronomical mechanisms.Indeed, the planets
    with their movement cause the entire solar system to vibrate with a
    set of frequencies that are closely related to the orbital periods of the
    planets.The wobbling of the Sun around the center of mass of the
    solar system is just the clearest manifestation of these solar system
    vibrations and has been used herein just as a proxy for studying
    those vibrations.The Sun, the Earth–Moon system and the Earth feel
    these oscillations,and i tis reasonable that the internal physical
    processes of the Earth and the Sun synchronize to them.

    Needless to say, Scafetta’s Empirical Model is beating the pants off the IPCC GCMs

    http://www.oarval.org/Scafetta_thumb.png

  44. Hi Richard C,
    Sorry if I misinterpreted what you were saying. Can you please share the data you have that shows that the Greenland ice sheet is melting but the rate is not currently accelerating?

    You seem to be saying that NAO it is so variable that it isn’t the driver of the increased ice loss we have seen over the last few decades. I agree with you on this point. However I don’t see any evidence of a 153 year melting cycle. Could you please clarify where you got this period from?

    Finally you seem to be claiming that the melting is caused by the vibration of the solar system but you have not been able to find any correlation between these postulated vibrations and the observed melting. Given this lack of observed correlation how do you know that this melting is about to reverse rather than continuing to increase?

  45. Richard C (NZ) on August 12, 2012 at 2:41 pm said:

    “Can you please share the data you have that shows that the Greenland ice sheet is melting but the rate is not currently accelerating?”

    “I don’t see any evidence of a 153 year melting cycle. Could you please clarify where you got this period from?”

    The distinction should be made between decadal/multi-decadal and annual surface melt (NASA’s Koening refers to annual melt below from the NASA Press Release), the latter annual event is clearly not accelerating but just a normal cyclical aberration.

    “Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time,” – Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data.

    Kurt Kjær, Shfaqat Abbas Khan and Kristian K. Kjeldsen have investigated a multi-decadal timeframe.

    Khan:-

    “We’ve used a combination of old aerial photographs from the 80’s to construct a digital elevation map and recent satellite data. In this way we’ve been able to gain an overview of the thinning of the ice sheet over the last 30 years in northwestern Greenland. We are the first who have been able to show that the Greenland Ice Sheet was on as a dramatic diet at the end of the 80’s as it is today. On the positive side our results show that despite a significant thinning in peripheral regions from 1985-1992; the thinning slowed and then died out.”

    Kjær:-

    “Our results show that the thinning of the ice sheet at the end of the 80’s and beginning of the 90’s eased over a 4-8 year period, after which a period of stability occurred until 2003. Our conclusion is therefore, that if we judged against longer periods of time, the current thinning of the ice sheet is likely to ease within an 8-year period.”

    “These variations in the amount of thinning that we are able to document since the 80’s make it difficult to predict how much the world’s oceans will rise over a longer period of time – a century for instance – as a result of Greenland glacial melt-water runoff. However, it is certain that many of the present calculations and computer models of ice sheet conditions that built upon a short range of years since 2000 must be reassessed. It is too early to proclaim the ‘ice sheet’s future doom’ and subsequent contribution to serious water problems for the world. In this context it should be mentioned that the Greenland bedrock rises as the ice sheet in the peripheral regions and especially near the coast is in retreat and becoming thinner. This highlights the enormous forces that are at play in Greenland and of how difficult it is to predict what it means for Greenland as well as the rest of the world,”

    http://news.ku.dk/all_news/2012/2012.8/Aerial-photos-reveal-dynamic-ice-sheet/

    “…you have not been able to find any correlation between these postulated vibrations and the observed melting”

    Give it time Nick, that’s the job of specialist scientists not me. When someone comes up with something I’ll let you know but given the superior performance (compared to IPCC GCMs) of a cyclical model then cycles are the sensible place to look. Note that Scafetta initially excluded secular and millenial cycles as explained here http://wattsupwiththat.com/2012/03/11/scafetta-prediction-widget-update/ but he’s subsequently progressed things a bit with Craig Loehle. I think the HadCRUT3 quadratic basis is flawed but that’s another story.

    “….how do you know that this melting is about to reverse rather than continuing to increase?”

    See Kjær quote above.

  46. Hi Richard C,
    Maybe you could have a look at the comments I made above.

    But to summarise:

    The Kjær paper deals only with the Northwestern part of Greenland and can’t be taken as a proxy for the whole. Satellite data and mass balance calculations over the whole ice sheet show acceleration.

    http://www.arctic.noaa.gov/reportcard/greenland_ice_sheet.html

    150 year is the average, not the actual period. The average over the last 5000 years is closer to 250 years. See

    http://www.igsoc.org/annals.old/21/igs_annals_vol21_year1995_pg64-70.pdf

    Perhaps you could address these points. As it stands your claim of no acceleration and that a surface melt event every 150 years is to be expected appears to be unsupported by the actual literature.

  47. Richard C (NZ) on August 12, 2012 at 6:53 pm said:

    “Perhaps you could address these points”

    The second point:-

    I think 153 years is the time lapse since the last event and the long-term average may be 250 years but so what? The annual surface melt aberration is cyclical i.e. not unprecedented and to be expected, “…this event is right on time” as Lora Koenig of NASA puts it.

    The first point you say:-

    “….mass balance calculations over the whole ice sheet show acceleration”

    We’ve also been over this before. Taking the studies one at a time and dividing into sample studies and whole ice sheet (remembering that Kjaer falls into the “no acceleration sample” category):-

    1) Surface mass balance along the K-Transect (sample)

    “Along the K-transect the surface mass balance (the balance between snowfall (positive mass) and melt water runoff (negative mass) during 2010-2011 was less negative than the previous record-breaking year (2008-2009)”. No acceleration.

    2) Surface mass balance from MAR simulations (whole ice sheet)

    Increasing 1958 – 1974, no change 1974 – 1994, decreasing 1994 – 2010. No acceleration and no anthro attribution.

    3) Greenland mass changes from GRACE (whole ice sheet)

    The study only begins in 2003. They say “2005-2006 had almost as much mass loss as 2010-2011”. No short-term acceleration.

    They cite Rignot: “Rignot et al. (2011) find an acceleration of Greenland ice sheet mass budget deficit during 1979-2010”. That paper here:-

    http://igitur-archive.library.uu.nl/phys/2012-0315-200618/rignot_etal_grl2011.pdf

    However, that is not unprecedented, There was also an extended high‐melt condition from the mid‐1920s to the early 1960s as reported by Bjørk, A. A., et al., 2012 with no impact on SLR, quoting:-

    “The forces acting in concert with ice melt across Greenland to produce higher global sea levels currently, should also have been acting during the extended high‐melt conditions from the mid‐1920s to the early 1960s. There is some qualitative indication of an observable influence of the variations in input from Greenland in the decadal rates of sea level change over the course of the past century… However, there is no indication that the increased contribution from the Greenland melt in the early to mid 20th century, a roughly 40 year interval when average annual melt was more or less equivalent to the average of the most recent 10 years (2000–2009), resulted in a rate of total global sea level rise that exceeded ∼3 mm/yr. This suggests that Greenland’s contribution to global sea level rise, even during multidecadal conditions as warm as during the past several years, is relatively modest.”

    That earlier event would also discount anthro cause.

    Rignot’s future extrapolation has been described as “rather naive” by Pat Micheals and Rignot et al also state “considerable uncertainty”:-

    http://www.worldclimatereport.com/index.php/2012/06/04/historical-imagery-of-greenland-glaciers-lessens-sea-level-rise-alarm/

    Micheals:-

    “The new Bjørk et al. (2012) study (as well as a slew of other recent studies which we have discussed: see here, here, here, here, here , and here for example) strongly suggests that “present trends” will not continue—and thus the Rignot et al. extrapolation is grossly inaccurate (i.e., far too large).”

    Finally, “…the present-day changes are not exceptional within the last 140 years”:-

    Surface mass-balance changes of the Greenland ice sheet
    since 1866

    L.M.WAKE,1 P. HUYBRECHTS,2,3 J.E. BOX,4,5 E. HANNA,6 I. JANSSENS,2 G.A. MILNE1

    ABSTRACT. Mass loss from the Greenland ice sheet over the past decade has caused the impression that the ice sheet has been behaving anomalously to the warming of the 1990s. We have reconstructed the recent (1866–2005) surface mass-balance (SMB) history of the Greenland ice sheet on a 55km grid using a runoff-retention model based on the positive degree-day method. The model is forced with new datasets of temperature and precipitation patterns dating back to 1866.We use an innovative method to account for the influence of year-on-year surface elevation changes on SMB estimates and have found this effect to be minor. All SMB estimates are made relative to the 1961–90 average SMB and we compare annual SMB estimates from the period 1995–2005 to a similar period in the past (1923–33) where SMB was comparable, and conclude that the present-day changes are not exceptional within the last 140 years. Peripheral thinning has dominated the SMB response during the past decade, as in 1923–33, but we also show that thinning was not restricted to the margins during this earlier period.

    http://dro.dur.ac.uk/5429/1/5429.pdf?DDD15+dgl3lmw

  48. Hi Richard C,
    Have another look at the MAR simulation section in the Arctic Report Card and have a think about whether it shows accelerating or constant mass loss. I’m happy to explain it to you but I figure you just misread the y axis.

  49. Richard C (NZ) on August 12, 2012 at 9:17 pm said:

    “I figure you just misread the y axis”

    Not at all, it’s an anomaly.relative to a 1971-2000 normal

    -150 to 0 is an increase from where it was at 1958 back to the normal, 0 to 0 is no change from the normal, 0 to -300 is a decrease from the normal.

    As I said “Increasing 1958 – 1974, no change 1974 – 1994, decreasing 1994 – 2010. No acceleration and no anthro attribution”

    That is of course, unless an anthropogenic effect begins at 1994 for some inexplicable reason.

  50. Hi Richard C,
    Do you realise that the y axis is Surface Mass Balance rather than total ice sheet mass? That is why the units are Gt/Yr rather than Gt. To clarify 0 means that there is no change in the total mass, not that the ice sheet has returned to the baseline mass. -100 (say) means that the ice sheet is losing 100Gt/yr. A positive value of 100 would indicate that the ice sheet is gaining mass at 100Gt/yr.

    From the start of the record until 1974 the line slopes up until it reaches 0. This indicates that the ice sheet continued to lose mass but the rate was getting slower, that is decelerating ice loss.

    From 1974 until 1994 the line hovers around 0 indicating that there was no significant ice loss or gain. It tell us nothing about the total mass of the ice sheet although you could infer it with integration if you so wished.

    From 1994 the total Surface Mass Balance slopes down meaning more ice is lost each year than in the previous year. This is acceleration in the rate of ice loss, I fail to understand how you can characterise it as anything else.

    I suspect you are confused because you are expecting to see a curving line to represent acceleration. In fact since the y axis is already a rate rather than an absolute measurement any sloping line represents a changing rate which is the definition of acceleration or deceleration.

  51. Richard C (NZ) on August 13, 2012 at 8:30 am said:

    “From the start of the record until 1974 the line slopes up until it reaches 0. This indicates that the ice sheet continued to lose mass but the rate was getting slower, that is decelerating ice loss”

    This is a decrease from the norm as I said, is it not?

    “From 1974 until 1994 the line hovers around 0 indicating that there was no significant ice loss or gain”

    This is no change from the norm as I said, is it not?

    “From 1994 the total Surface Mass Balance slopes down meaning more ice is lost each year than in the previous year”

    This is an increase from the norm as I said, is it not?

    There are 2 issues Nick:-

    1) Anthropogenic attribution – there isn’t any.

    2) Effect on SLR – there isn’t any

    Case closed.

  52. Richard C (NZ) on August 13, 2012 at 8:41 am said:

    Should be:-

    “This is a decrease [to] the norm as I said, is it not?”

  53. Hi Richard C,
    You said earlier:
    “2) Surface mass balance from MAR simulations (whole ice sheet)

    Increasing 1958 – 1974, no change 1974 – 1994, decreasing 1994 – 2010. No acceleration and no anthro attribution.”

    How can the rate be decreasing since 1994 but mass loss is not accelerating? Or do you agree that currently mass loss on the Greenland ice sheet is accelerating according to the MAR simulations?

  54. Richard C (NZ) on August 13, 2012 at 10:52 am said:

    “How can the rate be decreasing since 1994 but mass loss is not accelerating?”

    Remember what an “acceleration” actually is mathematically – don’t confuse it with a simple negative anomaly. Here’s the ARC 2010 graph which might help:-

    ARC Yearly Surface Mass Balance Change (blue and red lines 2-sigma)

    http://theinconvenientskeptic.com/wp-content/uploads/2010/12/ARC-2sigma-550×326.png

    And from that the years outside the 2-sigma range from the anomaly baseline

    http://theinconvenientskeptic.com/wp-content/uploads/2010/12/SMB-Dyn.png

    2010 only makes it if the Pettermann Glacier is included.(note the asterisk)

    1992 and 1996 are years of positive growth from the anomaly baseline of SMB.beyond 2-sigma. The SMB line moves from negative growth 1958 to positive growth from the anomaly in 1965 and back to negative growth from the anomaly in 1966ish. Similarly, SMB moves from positive growth from the anomaly in 1996 to negative growth in 2010.

    The current 2000 – 2010 negative anomaly is not unprecedented because the same thing happened around 1958.

    Here’s the 2010 ARC Greenland Mass Accumulation plot (total accumulated change in mass over the last 52 years):-

    http://theinconvenientskeptic.com/wp-content/uploads/2010/12/ARC-Accum-550×370.png

    The positive accumulation around 2000 offsets the negative accumulation around 1970 and we’ve got some way to go to match 1970 levels.

    In any event the scare is over – no anthro attribution – no SLR effect – case closed.

  55. Hi Richard,
    I find it fascinating that we can look at the same graph and see different things. In some ways this cuts to the heart to the two sides of the debate.

    Let’s stick to the MAR simulation data since 1994 which you say shows no acceleration.

    The mathematical definition of acceleration is:
    Change in rate (in this case Gt/yr) over time (Gt/yr^2).

    Between 1994 and 2010 the rate of ice loss went from 0 Gt/yr to 300 Gt/yr. This gives an approximate acceleration of 18.75 Gt/yr^2

    Could you explain how this rate change occurred if it did not accelerate?

    Perhaps it would help if you defined your understanding of acceleration from first principles as I have done above.

  56. Richard C (NZ) on August 13, 2012 at 12:19 pm said:

    Nick I’ve already laid out the case that the current situation is not unprecedented and nowhere near yet the levels of 1970 after the 1920 – 1960 event.

    There’s no anthropogenic attribution, no effect on SLR and therefore no scare.

    If you wish to deny all of that and prefer to revel in an irrational state of apprehension, feel free to do so – just don’t expect everyone to join you.

    Case closed.

  57. Richard C, accusations of denial and irrationality are unnecessary.

    Claiming that there is no acceleration in mass loss because the “current situation is not unprecedented” is not sound logic.

    Once again how exactly do you define acceleration?

  58. Richard C (NZ) on August 13, 2012 at 12:56 pm said:

    Not unprecedented

    No anthropogenic attribution

    No SLR effect

    No scare

    Case closed

  59. But you accept that the current ice loss in Greenland is accelerating? Questions of precedent and attribution can be addressed next.

  60. Hi Richard T,
    Your calculation in the lead article above uses 36Gt/yr as the ice loss for the whole of Greenland. The article you link to actually says this:

    “the ice sheet has lost some 36 billion metric tons of ice each year in recent years from its northwestern flank.”

    That is 36Gt/yr is only for part of the Greenland ice sheet. This makes your estimate for the length of time till the ice sheet disappears too high by about an order of magnitude and this still ignores the accelerating melting.

    Unfortunately this means the title of the whole thread needs correcting which sounds like a bit of an administrative pain. Perhaps a new post with the corrected calculation would be more appropriate?

  61. Richard C (NZ) on August 14, 2012 at 2:10 pm said:

    “,,,,still ignores the [recent but not unprecedented i.e. it’s happened before 1920 -1960] accelerating melting”

    Explains why extrapolation of the recent event has been described as “naive” by Pat Micheals.

  62. Nick,

    Perhaps a new post with the corrected calculation would be more appropriate?

    Yes, the original was focused on that area. My article still puts the melting into a useful perspective. But as I asked you earlier, do you think the melting is our fault and do you think we can stop it?

    How would you correct the article?

  63. Maybe Nick can vet all future blog posts for accuracy and correctness of titles. I am sure he would be delighted to take on this unpaid work in the interests of a fair and unbiased blogosphere.

  64. Hi Richard T,
    I guess there are two ways to correct it. You could use the surface mass balance for the whole Greenland ice sheet. There are some numbers you could use in the Arctic Report Card: Update for 2011 – Greenland Ice Sheet

    http://www.arctic.noaa.gov/reportcard/greenland_ice_sheet.html

    The Grace satellite data for example finds a loss of 430Gt in the 2010/2011 year.

    Alternatively if you are determined to reference the Scientific American article then you could figure out how big the North Western ice sheet is and apply your calculation to that.

    As for attributing causes to the melt I am sad to say that I think it is likely to be anthropogenic in origin. As for whether we can stop it only time will tell, it would be nice to at least try though. It is often surprising what can be achieved once humanity sets it’s eyes on a goal, the Curiosity Rover and the discovery of the Higgs boson are just two recent examples.

  65. Hi Richard C,
    If you are referring to Frauenfeld, O.W., P.C. Knappenberger, and P.J. Michaels, 2011. A reconstruction of annual Greenland ice melt extent, 1785-2009 then keep in mind they are referring to melt extent rather than mass balance and acceleration. They are not the same thing.

    As far as I can tell the accelerating loss of ice mass is unprecedented.

  66. As for attributing causes to the melt I am sad to say that I think it is likely to be anthropogenic in origin.

    Is this a “gut feeling, no science” (to paraphrase Phil Jones), or do you have something more to go on?

  67. Regarding the Frauenfeld et al. (2011) paper I believe you are referring to (correct me if I’m wrong) the authors themselves say that 2007 had the highest melt extent in their 228 year record which ended in 2009. 2010, 2011 and 2012 had higher peak melt extents than 2007 so I would definitely say that the recent extent of melting was unprecedented.

  68. Regarding the Frauenfeld et al. (2011) paper I believe you are referring to (correct me if I’m wrong) the authors themselves say that 2007 had the highest melt extent in their 228 year record which ended in 2009. 2010, 2011 and 2012 had higher peak melt extents than 2007 so I would definitely say that the recent extent of melting was unprecedented.

    So unprecedented within the last 228 years? Just trying to get some bounds on this unprecedented-ness

  69. Hi Andy, you are correct I should have been more precise and said:

    The current rate, acceleration and extent of melting is unprecedented over the instrumental record.

    I suspect that it may be unprecedented over the geological record as well because the forcings that caused previous melt events are not present in this instance. Feel free to share any peer reviewed evidence that you believe shows otherwise.

  70. Feel free to share any peer reviewed evidence that you believe shows otherwise.

    Maybe you could show me how you attributed the current melt to anthropogenic causes, peer reviewed of course.

  71. Richard C (NZ) on August 15, 2012 at 10:16 am said:

    “If you are referring to Frauenfeld, O.W., P.C. Knappenberger, and P.J. Michaels, 2011”

    Nope, Michaels “naive” description is of Rignot et al’s extrapolation

    “As far as I can tell the accelerating loss of ice mass is unprecedented”

    Nope, happened before starting 1920s. Accumulation reached a low 1970. We’re nowhere near that at present.

    http://theinconvenientskeptic.com/wp-content/uploads/2010/12/ARC-Accum-550×370.png

  72. Hi Richard C,
    You are aware that accumulation is different from acceleration right? If the figure you want to discuss shows acceleration from 1920 then let’s discuss it, but can you please fix the link first.

  73. Well, I find this 2012 paper pretty ironic as it states: “Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”
    http://www.the-cryosphere.net/6/821/2012/tc-6-821-2012.pdf
    It is already happening! What if the albedo feedback loops are so strong that the existing climate models are too conservative?

  74. Richard C (NZ) on August 15, 2012 at 12:04 pm said:

    “You are aware that accumulation is different from acceleration right?”

    There are phases. If acceleration occurs, whether positive or negative, then accumulation depends on the state of phase: loss 1920 -1970; then accumulation 1970 to 2000; then loss again 2000 to present.

    “If the figure you want to discuss shows acceleration from 1920”

    No it doesn’t, it’s an accumulation figure that shows loss – gain – loss as a result of phases. The first loss being far greater than the current loss.

    “….but can you please fix the link first”

    Nothing wrong with the link, there’s been problems like this on other blogs today. You should be able to recall the graph from memory (I can) because I showed it to you previously just yesterday here:-

    https://www.climateconversation.org.nz/2012/08/ice-cap-scare-just-67-millennia-left/#comment-111787

    We have raked this topic over some time ago with the same graphs Nick. Why do you insist on ignoring that which is contrary to your obvious bias so that we go over and over and over and over the same ground – it’s getting tiresome.

  75. Hi Richard C,
    Thanks for clarifying the graph you are talking about. I note that it ends in 2010 with accumulated mass only about 285Gt greater than the minimum around 1970. Given that the mass loss in 2011 was 344Gt (according to the Arctic Report Card) it would seem that the current loss of accumulated ice is now also unprecedented over the instrumental record.

    I also see that the figure you refer to shows that we have lost almost twice as much mass in the last ten years as we did in the previous period of loss that you refer to (pre 1970) which was slightly longer.

    So now we can see from the peer reviewed literature that:

    The low level of accumulated ice and the current rate, acceleration and extent of melting in Greenland is unprecedented over the instrumental record.

  76. Richard C (NZ) on August 15, 2012 at 1:26 pm said:

    “I note that it ends in 2010 with accumulated mass only about 285Gt greater than the minimum around 1970”

    “greater” ? Don’t you mean “less” ? The 1970 level is -900Gt, the 2010 level is -650ish.

    900 Giga ton loss 1957ish – 1972ish (about 15 yrs from series start but what happened prior to that starting around 1920?).

    1900 Giga ton gain 1972ish – 2000 (about 28 yrs)

    1600 Giga ton loss 2000 – 2010 (10 years)

    However, from 1985 – 1990 (5 yrs) the accumulation remained static at about 300 Giga ton gain but from 1992 – 1998ish there was a 700 Giga ton gain.in the space of 6 yrs.

    We will have to wait this current climate period to see if loss falls back to 1970 levels, extrapolation only gives misleading impressions depending on storyline.

    The fact remains that the largest observed movement has been a 1900 Giga ton gain over a close to conventional 30 yr climate period at a time when anthropogenic influence has been said to be paramount. Therefore, anthropogenic actions have resulted in Greenland mass accumulation using that rationale.

    Also opposite to alarming claims, neither the period of loss up to 1970, nor the present loss, has had an adverse effect on SLR, the latter having the perverse effect of SLR deceleration.

    Anthropogenic influence seems to have a beneficial effect on Greenland ice mass overall.

  77. Richard C (NZ) on August 15, 2012 at 1:40 pm said:

    Using the anthropogenic actions control Greenland ice mass rationale:-

    1) What anthropogenic actions caused the 1970 loss?

    2) What anthropogenic actions caused the 2000 gain?

    3) What anthropogenic actions caused the 2010 loss?

  78. Hi Richard C,
    I definitely mean greater. The accumulation level in 2010 is -650Gt which is greater than -900Gt in 1970. Of course the accumulation level in 2011 is -994Gt and this is the lowest level of accumulation on the instrumental record.

    So while you say “We will have to wait this current climate period to see if loss falls back to 1970 levels” we don’t have to wait another 20 years, the accumulation level is already lower than 1970. No extrapolation required.

    You also say “the largest observed movement has been a 1900 Giga ton gain” actually if you include 2011 the largest observed movement is the 1944Gt loss of mass between 2000 and 2011. This is about 3 times faster than the gain you cite.

  79. Richard C (NZ) on August 16, 2012 at 11:30 am said:

    So the loss was “greater” than 1970 closest to the the anomaly mean, then it became “lowest” further away from the anomaly mean than 1970 – this is a bit woolly Nick.

    “Of course the accumulation level in 2011 is -994Gt”

    Why “of course” ? Where did you get “-994Gt” from ?

    The Arctic Report Card States:-

    “…..April 2011….the ice sheet cumulative loss was -430 Gt”

    http://www.arctic.noaa.gov/reportcard/greenland_ice_sheet.html

    Now, about those anthropogenic attributions:-

    Using the anthropogenic actions control Greenland ice mass rationale:-

    1) What anthropogenic actions caused the 1970 loss?

    2) What anthropogenic actions caused the 2000 gain?

    3) What anthropogenic actions caused the 2010 loss?

  80. Richard C (NZ) on August 16, 2012 at 1:29 pm said:

    To clarify my comment

    The Arctic Report Card States:-

    “…..April 2011….the ice sheet cumulative loss was -430 Gt”

    What we should be looking at is this plot:-

    http://www.arctic.noaa.gov/reportcard/images-hydro/gr-fig19.jpg

    -700 Gt April 2010
    -600 May
    -590 June
    -850 July
    -1030 August
    -1200 September
    -1050 October
    -1050 November
    -1040 December
    -1050 January 2011
    -1025 February
    -1025 March
    -1020 April
    -1050 May

    OK, I see we are at total mass levels 150 Gt less than 1970ish.

    Mass fell sharply 610 Gt in 3 months June 2010 – September 2010 as it did in 2007.

    There were also sharp gains: 1972ish, 1983ish, 1992ish, 1995ish.

    http://theinconvenientskeptic.com/wp-content/uploads/2010/12/ARC-Accum-550×370.png

    So what we have is an overall cycle with sporadic sharp gains and losses.

    That’s going to make your anthropogenic attribution extremely difficult Nick – good luck with that (especially the +1050 February 2002 figure).

  81. Richard C (NZ) on August 16, 2012 at 1:39 pm said:

    Should be:-

    “[-1100] May

    OK, I see we are at total mass levels [200] Gt less than 1970ish”

    And,

    “(especially the [+1100] February 2002 figure)”

  82. Richard C (NZ) on August 16, 2012 at 3:12 pm said:

    Doing some long night shifts at the moment so now’s an opportune time to conclude.

    By Nick’s failure and default to provide any anthropogenic cause for: the 1972 -900 Gt loss; the 2002 +1100 Gt gain; and, the 2011 -1100 Gt loss, we agree that:-

    1) Greenland ice mass is a natural cycle of as yet undiscovered cause.

    2) Greenland ice mass loss or gain has no detectable effect on SLR.

    3) In the timeframe of the “anthropogenic era”, Greenland ice mass is a non-issue.

  83. Hi Richard C,
    It’s a shame you have to take a break. I have certainly enjoyed spending the time researching this topic with you. Before we finish up let me just edit your comments slightly and add some of my own to more accurately portray the situation as I understand it.

    1) Greenland ice mass has a natural cycle of as yet undiscovered cause, period or magnitude. This does not preclude an anthropogenic effect

    2) Current Greenland ice mass loss or gain has no detectable effect on SLR. Future Greenland ice loss will raise sea levels proportional to the amount of melt

    3) In the timeframe of the “anthropogenic era”, Greenland ice mass is a non-issue to people who believe the undiscovered cause of the accelerating melt is about to slowdown, stop and then reverse

    4) The current annual loss of ice in Greenland is unprecedented over the entire instrumental record

    5) The current rate of accelerating in ice loss in Greenland is unprecedented over the entire instrumental record

    6) The current peak extent of melt in Greenland is unprecedented over the entire instrumental record

    7) The current low level of Greenland ice mass is unprecedented over the entire instrumental record

    Thanks for your time on this issue, it is much appreciated and the discussion has broadened my understanding significantly.

  84. I agree with Nick on all counts. I also think that the increase of Greenland ice melt and the shift of the Northern jet stream are related although it is debatable which causes which. Hopefully 2012 is an outlier. If the 2013 northern summer is as extreme as 2012 you are going to get every AGW supporter saying “I told you so” and perhaps increased focus on climate change mitigation by the US and other affected Northern hemisphere countries.

  85. Thanks Simon, I appreciate the vote of confidence. The irony is that I had no idea how far into unknown territory Greenland was previous to this discussion.

    We are currently seeing events that are unprecedented in at least 8 generations. A little research into the peer reviewed literature is certainly eye opening.

  86. Maybe if Greenland keeps melting at this rate some more of the Viking artifacts will get uncovered. I am sure this will be a rich field to write some peer-reviewed papers on.

  87. Rolling Stone has just put out an interesting article on the effect of albedo on the Greenland ice melt. http://www.rollingstone.com/politics/news/the-arctic-ice-crisis-20120816

  88. How much science do you think we should take from Rolling Stone magazine, Simon? Anyway, Bill McKibben is not so much a writer on the environment as a leech on public anxiety about the environment. He makes statements designed to shock rather than reveal scientific fact. For example, in the Rolling Stone article he says:

    Box [a polar scientist] had conservatively predicted that it might take up to a decade before the surface of Greenland’s ice sheet melted all at once. That it actually happened in just a few weeks only underscores how consistently cautious ice scientists have been in forecasting the threat posed by global warming. Now, however, that caution is being replaced by well-founded alarm.

    It actually shows how wrong the predictions were, doesn’t it? Also, it’s misleading, bordering on fraudulent, to say “before the surface of Greenland’s ice sheet melted all at once.” For the truth is the melting affects only the top few millimetres.

    But we should hear a factual description of this “unprecedented” melt event. Perhaps we should listen to NASA, who said: “Measurements from three satellites showed that on July 8, about 40 percent of the ice sheet had undergone thawing at or near the surface. In just a few days, the melting had dramatically accelerated and an estimated 97 percent of the ice sheet surface had thawed by July 12.”

    1. What caused the melting? ANSWER: Not global warming. NASA said it was: “an unusually strong ridge of warm air, or a heat dome, over Greenland. The ridge was one of a series that has dominated Greenland’s weather since the end of May.” In other words, an unusual weather pattern. Just like the US drought.

    2. What happened after July 12? ANSWER: The water froze again as the temperature dropped. The scare has ended.

    NASA, clearly not experiencing McKibben’s fictitious “well-founded alarm”, also said that “Ice cores … show that melting events of this type occur about once every 150 years on average.” It is not unprecedented.

    Argue with NASA if you will. I’ll simply investigate anything blurted out by McKibben’s nervous temperament.

  89. Richard C (NZ) on August 18, 2012 at 12:11 pm said:

    Rolling Stone Mag is obviously not on NASA’s circulation list otherwise they would have received the Press Release:-

    “Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time,” says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data.

    http://www.nasa.gov/topics/earth/features/greenland-melt.html

  90. Richard C (NZ) on August 18, 2012 at 12:32 pm said:

    I see McKibbon states “NASA reported”, so it’s just spinning the alarm spin (a doubling down if you like) already in the NASA PR (with the erroneous title).

    The benign and mundane was surreptitiously inserted in the NASA PR and selectively overlooked by RS and McKibbon, all.in the interests of creating a crisis.

  91. Nobody mentioned AGW apart from yourself. Albedo isn’t anthropogenic apart from the unknown amount of soot and pollution from man-made sources. The point is that there may be a positive feedback loop both in terms of increasing albedo further increasing albedo and the melting increasing the likelihood of warm polar highs over Greenland in summer. The jury is still out.

  92. Richard C (NZ) on August 20, 2012 at 9:13 am said:

    1947 : International Agency Needed To Stop The Arctic Meltdown

    ARCTIC PHENOMENON Warming Of Climate Causes Concern

    May 30 1947.-The possibility of a prodigious rise in the surface of the ocean with resultant widespread inundation

    if the Antarctic ice regions and the major Greenland icecap should reduce at the same rate as the present melting in the Arctic, oceanic surfaces would rise to catastrophic proportions and people living in the lowlands along their shores would be inundated. He said that temperatures in the Arctic had increased 10 deg. Fahrenheit since 1900–an “enormous” rise from a scientific standpoint.

    “The Arctic change is so serious that I hope an international agency can speedily be formed to study the conditions on a global basis.”

    http://trove.nla.gov.au/ndp/del/article/46315410?searchTerm=climate%20change&searchLimits=

    H/t Steven Goddard

  93. Hi Richard C,
    What’s your point? That in 1947 there was a quiet news day?

    I don’t see how this is related to the state of the Greenland ice sheet. All it does is speculate about what might happen if it were melting. Today on the other hand we have evidence that not only is it melting, the rate of melt is speeding up and the is less ice today than at any previous time on the instrumental record.

    Perhaps you could clarify the argument you are trying to make.

  94. Richard C (NZ) on August 20, 2012 at 10:23 pm said:

    “What’s your point?”

    Just the amusing juxtaposition of the 1947 melting event and the response to it with the 2012 event and response (never mind the intervening growth).

    A bit like the 70s global cooling scare vs the 90s global warming scare.

    Just poking a bit of fun at your expense Nick.

  95. So in the absence of actual science that supports your position you have changed the subject and attempted to make a joke. Fascinating

  96. Richard C (NZ) on August 21, 2012 at 9:35 am said:

    It is “the absence of actual science” that does support my position Nick.

    The absence of detectable SLR as a result of melting.

    The absence of anthro attribution to mass growth/reduction events 40s, 70s, 00s and the absence of CO2-centric science to explain the 40s warming as shown here on figure 2-3A from the IPCC Third Assessment Synthesis Report:

    http://wattsupwiththat.files.wordpress.com/2012/08/ipcc_figure2-3a.png

    That 40s warming might just have had something to do with 40s Greenland melting though and the 70s cooling might have something to do with the mass growth, I don’t know – there’s an “absence of science”.

    So during that scientific absence, I’m filling in the time with the humourous aspect.of it all until something conclusive turns up. I think I’m going to need some more material.

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