Can we predict the duration of an interglacial?

Perspective by William McClenney on the paper of the same title by:

P. C. Tzedakis, E.W. Wolff, L. C. Skinner, V. Brovkin, D. A. Hodell, J. F. McManus, and D. Raynaud

http://www.clim-past.net/8/1473/2012/cp-8-1473-2012.pdf

I can often be heard, when assailed by the well-informed, climate, to ask the eminently reasonable question “In your opinion, how long will the Holocene last?” Rodney Dangerfield Syndrome then ensues, without exception so far, because astonishingly, few of the climate cognoscenti have even heard of the Holocene, much less pondered how, why, and by what mechanism it might, theoretically, be extended……

Plot showing the variations, and relative stab...

Plot showing the variations, and relative stability, of climate during the last 12000 years in our current interglacial period. (Photo credit: Wikipedia)

This IS the debate we should be having. So far, the Holocene has been quite the historically stable little interglacial, so far not exhibiting the normal climate instabilities of the typical end extreme interglacial.

But “Can we predict the duration of an interglacial?”

This, now week-old paper, explores a fascinating linkage concept, the inception and disintegration of the bipolar seesaw.

“We propose that the interval between the “terminal” oscillation of the bipolar seesaw, preceding an interglacial, and its first major reactivation represents a period of minimum extension of ice sheets away from coastlines.”

I will leave it to the experts to comment and debate as to whether or not we are perhaps seeing the onset of said bipolar seesaw in Arctic/Antarctic sea ice, and whether or not such is applicable in an anthropogenic greenhouse-gas world.

However, we might need to consider:

“…thus, the first major reactivation of the bipolar seesaw would probably constitute an indication that the transition to a glacial state had already taken place.”

As we work our way through this paper, we find:

“With respect to the end of interglacials, the MIS 5e– 5d transition represents the only relevant period with direct sea-level determinations and precise chronologies that allow us to infer a sequence of events around the time of glacial inception (Fig. 2).”

and this….

“Thus, glacial inception occurred ~3 kyr before the onset of significant bipolar-seesaw variability.”

and this…..

“Given the large decrease in summer insolation over the Last Interglacial as a result of the strong eccentricity-precession forcing, we suggest that the value of 3 kyr may be treated as a minimum. We thus estimate interglacial duration as the interval between the terminal occurrence of bipolar-seesaw variability and 3 kyr before its first major reactivation.”

This paper then proceeds to get very deep indeed into the evolution of the post-MPT interglacials, with an eye towards how each might be relevant to our interglacial times.

The take-home context, in terms of CO2 forcing might be encapsulated by this:

“A corollary of all this is that we should also be able to predict the duration of the current interglacial in the absence of anthropogenic interference. The phasing of precession and obliquity (precession minimum/insolation maximum at 11 kyr BP; obliquity maximum at 10 kyr BP) would point to a short duration, although it has been unclear whether the subdued current summer insolation minimum (479Wm−2), the lowest of the last 800 kyr, would be sufficient to lead to glaciation (e.g. Crucifix, 2011). Comparison with MIS 19c, a close astronomical analogue characterized by an equally weak summer insolation minimum (474Wm−2) and a smaller overall decrease from maximum summer solstice insolation values, suggests that glacial inception is possible despite the subdued insolation forcing, if CO2 concentrations were 240±5 ppmv (Tzedakis et al., 2012).”

Would you like fries with your Baked Alaska?

I have sent Anthony the raw and highlighted versions. A bloody good read.

cp-8-1473-2012 (PDF raw)

cp-8-1473-2012 HLT (PDF highlighted)

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74 Responses to Can we predict the duration of an interglacial?

  1. stew@hotmail.com says:

    the diagram is misleading. the 2004 point is a year measurement. the historical is averaged over 300 years. the last 100 year uptick is well within the natural variations which are large when compared to the averaged historical record displayed here

  2. ba says:

    These are actually the type questions that climate research was originally justified with and funded for: predicting the next, presumably inevitable, Ice Age.

  3. Mike M says:

    I think plate tectonics, such as divergence along the North American and Eurasian plates for example, cannot be ignored from the scope of things affecting the stability/predictability of ocean current patterns, especially those that transfer heat to the Arctic.

  4. Doug Huffman says:

    If it ain’t falsifiable then it ain’t science.

  5. John Doe says:

    This month’s Scientific American, Special Issue “Beyond the Limits of Science” has an article by Standford climate scientist Ken Caldeira who says the Holocene Interglacial isn’t going to end due to mankind and crocodile-like creatures will be living at the poles again.

    I thought the title of the special issue beyond the limits of science was apt in this case because Caldeira’s entire diatribe, which got more and more desperately catastrophic with each paragraph, was entirely beyond the limits of science and then some.

  6. AleaJactaEst says:

    Heresy, it’s heresy I say. Burn the witch!
    ….oh we can’t. There’s no wood. It’s too cold to grow trees. And we forced all the coal mines out of business. Damn this ice age.

  7. David says:

    I was wondering if anyone ever looked into temperature versus magnetic field strength of the earth. The temperature of the earth has been falling slowly for the last few thousand years and the magnetic field strength has done the same. This would allow more GCR into the atmosphere similar to a Grand Solar Minimum.

    Another theory is that nearby super nova events overwhelm the earth’s atmosphere with GCRs throwing us into the next ice age after increasing snowfall in the northern hemisphere.

  8. Joe Born says:

    Please, a little proofreading.
    E.g.:
    –”when assailed by the well-informed, climate, ” What is “climate” doing there?
    –”the normal climate instabilities of the typical end extreme interglacial.” Is something missing between “end” and “extreme”?

    I gave up after that.

  9. Myron Mesecke says:

    Off topic, forgive me. But the mention of Rodney Dangerfield made me think of all the alarmists that won’t release their data.
    “I put a bag over my data in case the bag over her data breaks.”

  10. Pamela Gray says:

    Agree. Also, the writer, given the above writing sample, could, with some encouragement, “step away from” the comma. Way over-used.

  11. Given that climate change tends along cyclic paths then it may be possible to predict the next ice age but then there is a chaotic input so timing will be out. Overall answer is no.

  12. Mike Haseler says:

    An interesting discussion paper … but I felt I was reading someone explaining how to divine the future from spots on the liver. However, let’s not forget that divination through examinations of the entrails did have a scientific basis (fluke) … so perhaps by pure fluke they have found something.

  13. Old Hoya says:

    Rats. Just when I had investors lined up for my Hudson Bay orange grove / coconut farm /tropic beach resort project (“Hansen-Gore Estates”), somebody has to go and bring up that return-of-the-ice-age thing. Can’t we stick to just one one phoney catastrophe scenario long enough for a guy to make a buck?

  14. Climate Weenie says:

    It is worth considering the glacial scale situation, for putting recent changes in perspective if nothing else.

    Looks like 60 to 100 thousand years more for the Holocene:

    http://upload.wikimedia.org/wikipedia/commons/9/90/InsolationSummerSolstice65N.png

    But that also means the for most of the next 100,000 years, the Arctic will be warmer than present. If one is saving the Arctic, one isn’t saving it for long.

  15. CodeTech says:

    Can we predict the duration of an interglacial?

    Absolutely we can! Heck, a 7 year old can! And the kids in my life definitely predict the next ice age every fall with the onset of cold (Canadian) weather.

    I’m guessing the missing word there is “accurately”.

    Can we Accurately predict the duration of an interglacial?

    Oops, okay, well, here’s the thing: unless the next ice-age begins basically tomorrow, we still won’t know if we were accurate. So the question needs to be:

    Can we create accurate, verifiable predictions regarding the duration of an interglacial?

    And the answer to that is: no.

  16. Alan the Brit says:

    Well, Pamela, having looked at the graphs, in the report, & on Wiki, at the Antarctic, the Greenland, Ice-core temp data, it would seem, that the last 4 interglacials, were warmer than today, by up to 5°C! ;-) Mind you looking at the graphs for the last 12,000 years, temps were warmer than today back then, & we’re supposed to be wearing dark-brown underwear all because of the last half-inch on the graph that shows an uptick in temps, but still less than 10,000 BP? Barking, absolutely barking!

  17. H.R. says:

    We have nukes, now. The glaciers advance when we say they advance, right?

    But seriously folks, my question is that when we come to the end of the Holocene, can we prevent the next glaciation? If we can, what could possibly go wrong?

    As for predicting the end of the Holocene, the margin of error is what counts. Perhaps we can predict the end to +/- 500 years; heck! make it 200 years. Sounds like a reasonable error, eh? But who is going to remember the glaciers are coming? What if we prepare and the preparations go to dust because the Holocene ends long after the preparations are forgotten? How will we know the prediction was right until after it’s too late anyhow?

    Nice to see someone is taking a look, though.

  18. John Ratcliffe says:

    Today being one of those days when the brain is not working very well, the only question that I can give a reasonable answer to, is –
    “Would you like fries with your Baked Alaska?”
    Answer — No. A deep fried Mars bar please.
    John r

  19. Doug Proctor says:

    The last 12,000 years of temps: the various temp estimates show large, sudden variations that the smoothed, averaged one doesn’t. This reflects uncertainties that I ask about (rhetorically, as there is no apparent answers):

    1) are various estimates actually more accurate than understood, because they are more regional than global?

    2) are past temperature variations greater than today, so that when we blend and smooth the past we are forcing a stability on history that didn’t exist today?

    3) are the recent 150 years of temperature variation “normal”?

    If we have forced the past to reflect the present, then ALL the CAGW narrative falls down. There is LESS temperature variation inherent through CO2 than in some unknown, rapid-onset process we have experienced many times over.

  20. Jack Linard says:

    “I can often be heard, when assailed by the well-informed, climate, to ask the eminently reasonable question “In your opinion, how long will the Holocene last?””

    WTF does this mean??

  21. John West says:

    “In more general terms, the analysis presented here emphasizes the “memory” of the climate system, whose response to insolation forcing depends on the evolution of astronomical parameters and their integrated effects over time, rather than the instantaneous forcing strength.”

    If only there was a large fluid heat sink to account for climate “memory”.

    Oh, here it is:

    “A number of feedbacks and mechanisms (snow-albedo, ocean dynamics, equator-to-pole moisture transport, sea-ice-albedo,forest-albedo) combine synergistically to amplify glacial inception (e.g. Khodri et al., 2001; Crucifix and Loutre, 2002; Vettoretti and Peltier, 2004; Calov et al., 2005).”

    Ok, let me get this straight, the climate has memory (resists change) and yet these same mechanisms “combine synergistically to amplify glacial inception”. So, the climate can be both sensitive (+ feedbacks) over long geologic time frames and insensitive ( – feedbacks / dampening mechanisms) over short geologic time frames to an insolation “forcing”.

    Isn’t that one of the basic “skeptic arguments” against the need for immediate action to curb climate change by emission reductions? That any change in climate due to GHG emissions (enhancement of the GHE) will be slowed and moderated (mostly by the ocean) to the point that both civilization and ecosystems will merely adapt, perhaps without even noticing (as the case with NYC shoreline over the last century +).

  22. TomE says:

    I have a feeling that without WUWT this paper would not get a lot of reading and unfortunately from this retired engineer not a lot of understanding.

  23. David Larsen says:

    I have asked the same question myself. I will repeat my experience. I grew up in the middle of Racine county WI. The last glacier (Wisconsionian in US, Wuerm in Europe) pushed some of the finest topsoil down to there and left many drumlins, kettles and morains. I can remember picking glacial till from our fields that were rocks pushed for thousands of years and rounded to where they are today. We have a zero degree magnetic declination along that spot. Does the earths magnetic declination follow the old glacial path? Then look at the aurignacian oscillations that followed the glacial melting. Extreme temperature variations caused by: the earth heating and cooling from the sun? Very dynamic and bound to happen again.

    I am an enrolled Native American. My blood and phenotype can be traced directly back to northern Mongolia. My distant relatives crossed over from Asia during the last glacial period. I say during the second to last one, not the last one. That would have been around 30-40 thousand years ago. Awesome.

  24. gymnosperm says:

    The short answer is no, we can’t predict when the holocene will end, particularly by using orbital forcings. We also have no idea if human CO2 will be a factor as CO2 typically overshoots and lags the temperature decline.

  25. beng says:

    Recommend reading this paper carefully. Alot of good info. And for those thinking all interglacials last only ~10kyrs, think again.

  26. Tom in Florida says:

    The current period of glaciation spotted with interglacial periods as only been around about 3 million years, a relatively short period of Earth history. Why should we assume this will continue? Perhaps it is now the end of this period of climate and the Earth will once again be mostly warm for the next 20 million years.

  27. Mickey Reno says:

    Thanks for the PDFs. I so appreciate being able to read the actual document over reading a abstract of the paper on some paywalled site.

  28. connertownlive says:

    “Will this wind, be so mighty, as to lay low, the mountains. of the earrrrrth?”
    No!

  29. keith at hastings uk says:

    early snowfall in Iceland I read. Only weather of course. But they are already digging sheep out.

  30. peterhodges says:

    NO.

    Duh. They can’t predict the weather a week in advance.

    We really don’t know what causes the Glacials/Interglacials, or even the oscillations within the Holocene for that matter.

    However, simple curve matching shows the current interglacial is about over – if the previous ~1my pattern prevails.

  31. Joachim Seifert says:

    The analysis is rather bad science….because
    -> not one word about the 50,000 year duration of the Anthropocene…
    -> a variety of parameters are listed ….but completely missing are Holocene
    calculations and temperature reconstructions based on their findings, no formulae,
    no calculation results for the course of temp evolution over the Holocene given….
    -> the paper title is answered at the bottom with “”We SHOULD be ABLE to predict…..””
    But what is in the way? Is it professoral ineptitude? Need more million grants?
    We should, but…hm….we…. sorry….. folks?
    -> questionable phrasings: “Our analysis concerns the “memory
    of the climate system”?? What is the memory of the system? What causes the
    memory?
    -> 5 orbital macro-forcings are completely MISSING in the paper, clear professoral
    ineptitude, see paper —–with extensive Summary :

    -> If desired, for the purpose of comparison, we would present this brand new Holocene
    paper with Anthony, if he allows….and you will have a clear, calculated, transparent
    and comprehensive answer, for finally discard all speculations with “should” and
    “would”, due to “climate memory.”…
    JS.

  32. Laurence Crossen says:

    The Milankovitch mechanism was not accepted during the middle of the twentieth century because it was recognized to be inadequate in amplitude. When a significant fluctuation was found in the deep sea cores it was taken as evidence and Milankovitch was accepted. It still does not amount to a mechanism.

  33. Joachim Seifert says:

    Admin: The link did not pop up, why?

  34. Joachim Seifert says:

    Maybe because of the brackets? Again without brackets:
    http://www.knowledgeminer.eu/eoo_paper.html
    Thanks JS

  35. Blade says:

    I’ve long believed that decreasing sea-levels is the only evidence humans will ever see of a complete Holocene interglacial and shifting back to large-scale glaciation. Looks pretty obvious to me when you examine the famous Meltwater Pulse graph …

    http://upload.wikimedia.org/wikipedia/commons/1/1d/Post-Glacial_Sea_Level.png

  36. poitsplace says:

    @John West (And anyone else that cares to listen)
    > Isn’t that one of the basic “skeptic arguments” against the need for immediate action to curb climate change by emission reductions

    The glacial-interglacial transitions represent fluctuations between two strong attractors. Feedbacks become weak and even negative toward progression beyond those points. The states between have high feedbacks…and this difference between feedbacks strengths is clearly visible in the ice core record.

    The reason for this is that the feedbacks are moisture driven and have no significant contribution by CO2. Honestly, how anyone would be stupid enough to think a 100ppm CO2 change contributes significantly when we’re talking about 40% of the earth’s surface being covered in ice is beyond me. They also get rather precarious…since some of the ice sheets are sitting on exposed continental shelf…leading to innundation feedback as well as normal feedback.

    Can we predict when the holocene will end…most likely no. The problem is that its a slow transition. It could happen at any time within a window that’s probably a thousand years or more…and then an unexpected event happens that causes significant cooling. Bam, the world is plunged into temperatures that trigger sea ice that can extend to within 50 degrees of the equator. Once you look at it in these terms BTW, you realize that only an incredibly inept scientist would ever be stupid enough to say our current arctic restricted sea ice will contribute meaningful amounts of feedback. (just passing through so I won’t be looking back for replies)

  37. David L. Hagen says:

    Death by Dzud
    We can see a glimpse of the consequences of the next interglacial by examining the 2010 Dzud in Mongolia:
    Death and suffering in the land of Genghis Khan CMAJ March 22, 2011 vol. 183 no. 5 First published February 22, 2011, doi: 10.1503/cmaj.109-3796

    It started with a drought in the summer of 2009, a so-called “black dzud.” The drought prevented herders from stockpiling animal fodder for the winter. The extreme winter weather that followed compounded the problem. Heavy, prolonged snowfall — called a “white dzud” or, more presciently, a “white death” — prevented animals from grazing.

    Herders, trapped in their gers (traditional round felt tents sometimes called yurts), were unable to reach their herds to keep them moving. Many animals simply froze to death in situ. An additional problem was the sheet of ice, or “iron dzud,” that formed over pasture-land, a barrier animals couldn’t penetrate. By the spring of 2010, more than eight million livestock had died, triggering widespread food insecurity in many regions across Mongolia.

    The Great Famine in Finland 1695-97
    Neumann, J., S. Lindgrén, 1979: Great Historical Events That Were Significantly Affected by the Weather: 4, The Great Famines in Finland and Estonia, 1695–97. Bull. Amer. Meteor. Soc., 60, 775–787. doi: http://dx.doi.org/10.1175/1520-0477(1979)0602.0.CO;2

    In the years 1694 to early 1697, cold winters and cool and wet springs and autumns led to extreme famine in northern Europe, particularly in Finland, Estonia, and Livonia. It is estimated that in Finland about 25–33% of the population perished (Jutikkala, 1955; Muroma, 1972), and in Estonia-Livonia about 20% (Liiv, 1938).

    Uncertain climate sensitivity
    What confidence can we currently have that CO2 warming will be sufficient to avoid the next glaciation? Published climate sensitivity varies by more than an order of magnitude. e.g. from 4 C/CO2 doubling. Consequently, I rate as very low any confidence we can have that anthropogenic global warming will prevent the next glaciation.

    The dangers from another interglacial are far greater than of global warming.
    With such great dangers, it is prudent to consider what actions we can take to avoid such global cooling and glaciation and the associated famines and severe hardship.

  38. dscott says:

    Blade: I’ve long believed that decreasing sea-levels is the only evidence humans will ever see of a complete Holocene interglacial and shifting back to large-scale glaciation.

    Excellent observation of the empirical evidence. During the Little Ice Age sea levels dropped to around 18 inches below today’s levels, during the Roman Warming sea levels rose to approx. 18 inches above today’s levels. A reasonable hypothesis would be to postulate that every GAT has its corresponding sea level. The conclusion is when we see sea levels stabilize, i.e. not rising we know a “tipping point” has occurred in the GAT and it should be easily determined by a minimum two year level off or peak with a decline to the previous year (which would be unprecedented in modern times.)

    That being said, observation of the geologic record matched with the obliquity chart demonstrate that EVERY interglacial ends when the obliquity of earth declines below 23.5% without exception for the last 1 million years of the all the geologic records. That being the case, yes, a prediction can be made as to when the interglacial ends. However, that prediction can only be made based on records that can give us accurate data down to the time scales desired. You can’t give a year certain if you don’t have the geologic data that gives you year by year increments. Whatever the smallest time scale increments are available, that is the smallest increment you can predict with any precision.

    So here’s a challenge to the scientific types: What is the smallest time increment on the data we currently have regarding the beginning of the last Ice Age? Match that to the descending obliquity curve and the known sea level at that time to determine what the exact obliquity angle was. Once you have the exact angle corresponding to the onset of the last Ice Age you then can accurately calculate/predict the beginning of this coming one.

  39. RockyRoad says:

    At least they’re talking about it. I was worried they were so convinced that some unforseen, undefined, nebulous CO2-induced tipping point would push the earth into some catastrophic climate disaster rather than the next Ice Age which is sure to come.

    Bet on it. The probability is 100%. The future will be cold.

  40. J Martin says:

    “We thus estimate interglacial duration as the interval between the terminal occurrence of bipolar-seesaw variability and 3 kyr before its first major reactivation.”

    Anyone got any views on what the above means in plain English ?

    The glaciation has started ? not started ? will start in 3k years ? started 3k years ago ? or something else. Or are they saying they just don’t know ?

    Did they come to a conclusion ?

  41. J Martin says:

    dscott

    I was under the impression that obliquity ruled the 41k World. But that a better match since then is provided by precession (perhaps perversely). Although there’s perhaps that 100k thing going on.

    Certainly not enough work is being done on trying to predict the timing and pace of the next glaciation.

    Are there any proxies from Canada that can tell us if they could have grown wheat during the Little Ice Age ? If Livingstone & Penn are correct we may find out soon enough.

  42. phlogiston says:

    Great paper William, thanks. Its quite remarkable the way people hide from this question “when will the current interglacial end”. It reminds you of accounts from firemen of how people sometimes hide in cupboards when a house is on fire thinking this will save them.

    Actually reading the paper makes it clear that – in the absence of a “deus ex machina” intervention by CO2,driving temperatures contrary to all palaeo climate evidence which states that CO2 follows temperatures – then this interglacial will be short, i.e. will end within 1000-3000 years.

    This is clear from the early peak of the Holocene, 4-5000 years from the inception, and also the phasing of the Holocene with the summer insolation and obliquity wavetrains.

    So we have to face a choice (out of the closet now folks):
    either CO2 actually is warming the planet anomalously for the first time (as it never has before) in which case
    (a) it might save us from a descent into interglacial, but (b) in that case we have to face the litany of disasters associated with CAWG preached from CAGW pulpits around the world; or
    (b) CO2 will not prevent the coming end of interglacial, so within 1000-3000 years temperate latitudes will cease to be habitable, being under ice, including North America, North Europe, North China, south of South America, etc…

    Take your chance, adventurous stranger
    Strike the bell and bide the danger
    Or wonder, till it drives you mad
    What would have happened if you had.

    C.S.Lewis, The Magician’s Nephew

  43. Steve Short says:

    Once the Great Green Religion has swept the developed world free of skeptics, deniers, denialists, tobacco and oil company stooges and all manner of equivalent filth then we will have all been sent back into some sort of halcyon, agrarian where we are all running around dressed as hobbits, praying towards Woodstock and hugging trees twice a day. This will result in us all having to cultivate large patches of kale etc with our bare hand and keep pigs, goats, rabbits, on our little self-sufficent patches of total sustainability. As in Roman times this will vastly increase the number of intestinal parasites everyone carries around with them. These are collectively known as ‘flukes’. refer:
    http://www.uptodate.com/contents/intestinal-flukes
    This is turn will lead to a massive revival in the use of entrails (intestines) for the prediction of the future. This in turn will enable quite accurate consortial modelling of the exact end of the interglacial due to the very high number of flukes. So we can then be relaxed about it.
    PS: Happily, I suspect this process already got going around 2008/9. I’ve got my fingers crossed.

  44. jbird says:

    The question is moot. The Holocene is over. The evidence will become obvious to most of us within our current lifetimes. These cycles are inescapable.

  45. Pamela Gray says:

    Dear Mr. Alan the Brit,

    I have spit, mind you, hot coffee, that I just poured into a warmed mug, all over my, “otherwise clean”, computer (she said pausingly).

  46. Simple answer no. If one hedges by placing several large qualifiers on the guesses being made then sort of. Trying to guess the length of the Holocene is like guessing the average temperature 50 years from now. This is a nice game but only a game and should only be played in the school yard so no one takes it more seriously then any other guessing game.

  47. captainfish says:

    I haven’t the foggiest idea what this article is about. I understand the Holocene and the article’s quest to try and see if someone can determine a length till next glaciation. However, everything after that is in non-English.

    What I have always liked about WUWT is that it laid out the scientific and then broke it down in layman’s terms. Of late, co-authors seem to leave articles at the former.

  48. sunsettommy says:

    The Holocene is around 16,000 years old.

  49. Mac the Knife says:

    Pamela and Allan the Brit,
    Regardless of the ‘confidence interval’, or lack of confidence interval, that can be applied to this analysis of interglacial duration predictions, I choose to remain a skeptic, and am adding another 2 full cords of dry fir, or alder, to my wood pile, which already is comprised of 3 full cords of 2 year dry white oak, a wonderful, high BTU, long burning hardwood firewood, not commonly found in The Great North Wet!
    Best Regards, Fellow WUWT Fans!
    MtK
    PS: I have a ‘privacy screen’ overlay on the LCD display of my laptop, not because I really need privacy, but because it is easily washable, when I need to get laugh induced “spewage” off it! Highly recommended for WUWT participants!

  50. gymnosperm says:

    Joachim Seifert says:

    October 2, 2012 at 11:43 am

    “not one word about the 50,000 year duration of the Anthropocene…”

    ========================================================================
    Puleeeze! Talk about anthropocentric. Have you seen this scene from the Paleocene? “Cenes” are major divisions of the Cenozoic. Even the Holocene is ridiculously overdrawn. It is really just another interglacial, the thirteenth in the last million years. (Whoops, so much for 100,000 year periodicity)

    To name a “Cene” after us naked apes, sapiens sapiens, in the middle of the last glaciation, 20,000 years before we had driven poor Homo erectus to extinction, is the very pinnacle of arrogance. IMO.

  51. phlogiston says:

    Joachim Seifert says:
    October 2, 2012 at 11:43 am
    The analysis is rather bad science….because
    -> not one word about the 50,000 year duration of the Anthropocene…

    Your post is rather bad …. because
    -> not one word about the 10 year AlGorocene.

  52. phlogiston says:

    captainfish says:
    October 2, 2012 at 8:38 pm
    I haven’t the foggiest idea what this article is about. I understand the Holocene and the article’s quest to try and see if someone can determine a length till next glaciation. However, everything after that is in non-English.

    The bit I found particularly hard to understand was “Would you like fries with your Baked Alaska?”

  53. E.M.Smith says:

    Certainly we can predict the duration of an interglacial: “It will be long”. But not long enough….

    Oh, more precise? It will end in a few thousand years.

    Since the onset of ice is sawtoothed with the growth mass transfer limited, but the melt rain accelerated, the growth of the ice sheet to full size takes about 80,000 years. As it’s about 1800 miles form the residual of the ice sheet on Greenland to where it ended in New York (wild ass guess from looking at map) I make that about 9/400 mile / year (or about 120 feet per year). That means you can walk away from the advancing glacial onset with a short stroll once per decade. The average person will need to move one and 1/2 mile further south each lifetime, so tell your kids to pack up and move 3 miles south of you and they will be all set until the grand kids are grown and done…

    (Even if off by a factor of 2, it’s an irrelevancy)

    I’d even go so far as to assert that the Interglacial has already ended. There are some long cycle processes ( one 5000 years, another about 180 years) and the Little Ice Age was the start of the drop. But it arrived during a ‘dip’ of one of those longer cycles, so we rode a rising wave out of it. Just not as warm as the PRIOR rise… We’re having “lower lows” and “lower highs” already. When this cycle tops and falls, we go further into cold than during the L.I.A.; then in 200 to 400 years warm out of it again… just not as warm as THIS time. Repeat…

    So more important to most of us is ‘when this oscillation ends’ and we head back to a L.I.A. drop (as it’s faster than the glacial). IMHO, that’s in the current sleepy sun period from now to 2040.

    Looked at another way, a long human lifetime is 1/1000 of the glaciation process. We just don’t live long enough to even notice it…. The warming out of a glacial is a different matter….

    Look at the (inverted) ice volume in this graph:

    https://en.wikipedia.org/wiki/File:Ice_Age_Temperature.png

    It slowly builds over the entire glacial, then suddenly melts in one spectacular rush. (It does get cold fast, but folks in Canada and Russia are already used to cold ;-)

    For folks thinking we’re doing a nice flat with ringing wobble from the chart in a comment above; that’s the orbit. Look at the historic very long term temperature trend, and we’re colder:

    https://en.wikipedia.org/w/index.php?title=File:Five_Myr_Climate_Change.svg&page=1

    That’s 5 million years. Steadily colder. So it takes less “orbital change” to get to making ice cold over time. Where we used to warm enough to exit an ice episode every 41 kyrs, it is now only warm enough every 100 kyrs. Eventually even that won’t be enough. (The last 1/2 million years we’ve dipped deeper and spend more time colder…) Basically, our “natural state” is frozen. Only rarely do we enter an odd configuration that can melt the ice; but that’s going to run out too…

    Hopefully not too long after that the continents will move enough to warm things up.

    I really think folks need to fully absorb the point that the natural state is FROZEN. Only rarely is it warm enough to melt north polar ice. As soon as we have persistent multi year ice at the North Pole that accumulates decade over decade, we’re headed back into the freezer…

  54. Tom in Florida says:

    At the start of this interglacial obliquity was approaching highest (24.5) and NH summer solstice was nearing perihelion. This combination will not come together again for another 80,000 years or so. If Leif is correct and the climate stays warm until then due to low eccentricity it may be that the Earth will not return to glaciation for another 90 – 100,000 years.

  55. Brian H says:

    Tom;
    Oh, yeah? I betcha 2 bn. quatloos yer wrong. Lief, too.

    REPLY: You probably ought to learn how to spell Leif’s name correctly before saying he’s wrong. – Anthony

  56. J Martin says:

    E.M.Smith said “We’re having “lower lows” and “lower highs” already. When this cycle tops and falls, we go further into cold than during the L.I.A”

    If we see temperatures dip below those of the LIA, in the coming 20+ years then I reckon that may be a reasonable indicator that we are stepping down from our current interglacial towards the next full glacial.

    This last graph on the linked page below from Tallbloke’s Blog suggests that that might be the case, if only they had extended it another two hundred years. Note that the two largest curves didn’t fully coincide during the Maunder Minimum, but it looks as if they will come much closer to doing so during the forthcoming minimum, thus producing temperatures lower than those reached in the Maunder.

    http://tallbloke.wordpress.com/2012/09/20/how-the-temperature-datasets-tell-us-extra-co2-has-little-effect/

  57. dscott says:

    Tom in Florida says:
    October 3, 2012 at 7:52 am
    At the start of this interglacial obliquity was approaching highest (24.5) and NH summer solstice was nearing perihelion. This combination will not come together again for another 80,000 years or so. If Leif is correct and the climate stays warm until then due to low eccentricity it may be that the Earth will not return to glaciation for another 90 – 100,000 years.

    Not according to the geologic record.

    An Ice Age does not come to an end at the top of every obliquity cycle at 24.5 degrees, it only ends at that point on the 2nd or 3rd time of the max. Precession may indeed determine IF an Ice Age ends but only in combination with the peak of the obliquity cycle. However, the geologic record is clear without exception, EVERY interglacial ends at the down swing of the obliquity cycle when it passes 23.5 degrees. NO EXCEPTIONS!!!!! The only relevant question is at what degree below 23.5 does the interglacial actually officially end? 23.44, 23.43, 23.41? This is an event driven process, not a time driven process. Time is merely the derivative of the cause not some magical effect. 100 kya is an average of the Ice Age cycles that last 80 kya and 120 kya, this why it does not look like it matches the 41 kya obliquity cycle. It’s a basic math error employed by those who refuse to accept the Milankovich theory by obfuscating the timing.

    Empirical analysis is the only valid scientific method that ends in reproducible results. Magical thinking in terms of the effects of CO2 at such absurdly low atmospheric concentrations does not bear out in reality. Earth is not Venus with it’s 90 bar pressure CO2 dominated composition, thus not an analog as many warmists would like you to accept.

    Chaos is not the absence of order, chaos is the inability to understand the order. Weather and Climate seem chaotic because we don’t understand the variables.

  58. Tom in Florida says:

    Brian H says:
    October 3, 2012 at 9:52 am
    “Tom; Oh, yeah? I betcha 2 bn. quatloos yer wrong. Leif, too.”

    You are on! Let’s meet in 92012 so I can collect.

  59. J Martin says:

    23.5 degrees obliquity is where we are now.

    Combine that with our reducing magnetic field and the Livingston & Penn goodbye to sunspots graph and this minimum we are currently embarked on might go somewhat deeper and longer than many would like. It will almost certainly reduce the church of co2 to the smallest religious congregation anywhere.

    A closer look at obliquity and those inter-glacial terminations would indeed be interesting.

    I vote that we pour money into Thorium and Fusion research like there’s no tomorrow.

    Up to now we have named minimums, Dalton, Maunder, Sporer etc. with a split over the name for the next one (this one) between Eddy and Landscheidt. Yes Eddy was a great solar scientist, but Landscheidt predicted this minimum back in 83. Perhaps this pending glaciation will be named after one of those two gentlemen.

  60. Tom in Florida says:

    dscott says:
    October 3, 2012 at 12:32 pm
    “.An Ice Age does not come to an end at the top of every obliquity cycle at 24.5 degrees, it only ends at that point on the 2nd or 3rd time of the max. Precession may indeed determine IF an Ice Age ends but only in combination with the peak of the obliquity cycle.”

    That’s what I said.

    “Tom in Florida says: October 3, 2012 at 7:52 am:
    “At the start of this interglacial obliquity was approaching highest (24.5) and NH summer solstice was nearing perihelion. This combination will not come together again for another 80,000 years or so…..” ”

    Perhaps I should have added “when another interglacial will commence”.

    I did add IF (that’s a big IF) Leif is correct about the influence of eccentricity, the climate may not enter a frozen period until we get close to the next time conditions are ripe for an interglacial, which would mean one long period of the Earth not being in a glacial state.

    I wasn’t as clear as I should have been.

  61. J Martin says:

    23.5 degrees to 23.4 degrees takes about 500 years, so maybe I don’t need to move to Australia just yet, assuming that’s a good choice.

  62. J Martin says:

    dscott.

    Is your 23.5 degrees based on Antarctic ice cores, presumably Vostok, or Greenland ice cores, or other cores, or what.
    Where do you get this info from ?

  63. phlogiston says:

    Tom in Florida says:
    October 3, 2012 at 2:07 pm

    I did add IF (that’s a big IF) Leif is correct about the influence of eccentricity, the climate may not enter a frozen period until we get close to the next time conditions are ripe for an interglacial, which would mean one long period of the Earth not being in a glacial state.

    This idea by Leif Svalgaard and others that the current low amplitude node of eccentricity oscillation means no glaciation, is contradicted both by the fact that an interglacial ended as normal about 400 kYrs ago in exactly the same eccentricity setup, and also by the research of Tzedakis posted by William McClenney, who has repeatedly published the finding that the lack of insolation forcing does not prevent an interglacial from ending.

    If there were to be tens to hundreds of thousands of years of (unprecedented) sustained interglacial, this would effectively mean the end of the current glacial epoch. One would – presumably – require something resembling evidence to support such a dramatic prediction.

    From 1 million Yrs ago to 2 million Yrs ago, the 41 kYr obliquity oscillation controlled glacial / interglacial timing. Then for the last million years the system switched to being entrained by the 100 kYr eccentricity oscillation. No one has come close to explaining this transition – few indeed even pay it any attention. The “science” of analysing what causes glacial / interglacial switching and pattern is in utter infancy and has a very long way to go before becoming serious and effective science with anything like real answers. And until it incorporates a understanding of the dynamics of weakly forced nonlinear oscillators, there is zero chance of it doing so, ever.

  64. phlogiston says:

    E.M.Smith says:
    October 3, 2012 at 2:36 am

    Since the onset of ice is sawtoothed with the growth mass transfer limited, but the melt rain accelerated, the growth of the ice sheet to full size takes about 80,000 years.

    Its not quite such a simple, saw-tooth. Looking at the last million years or so temperature record, you cant really say you have a linear decline from end of interglacial to glacial minimum, 80,000 years later. In fact every interglacial ends with a steep fall, usually to something like “half glacial”, a state much, much colder than a mere little ice age. So cooling at the end of an interglacial can at times be more rapid than you suggest.

    Another interesting thing is that, while global temperatures are cooling toward glacial, temperatures are more unstable with higher amplitude fluctuations. Supposed glacial periods are punctuated by “micro-interglacials” lasting less than a century.

    It is interesting to speculate if fractal property of climatic processes means the same at shorter timescales, that is, on a century or decadal scale, or even month to month scale, more fluctuation in global temperature is observed during periods of falling as opposed to rising temperatures.

  65. William McClenney says:

    Love all the comments folks. I wanted to just lay this one out there with minimal introduction to see the range of reactions. The range is what is fascinating! We have a tantalizing paper to be released by Joachim Seifert, which I hope he makes available to us, to Jack Linard whom I hope may now realize that the future of this rather pleasant little interglacial is also a matter of some debate.

    Because even on things which actually have happened, the sciences is not that particularly well-settled. Which makes consideration of the science being settled on things which have not happened yet a bit unsettling………

    When I add a half-precessional cycle old post-MPT interglacial with anomalous, but otherwise typical end-interglacial overshoots of CO2 with the triple thermal peaks at end-MIS-19, the single peak at end-MIS-11, the pair of thermals at end-MIS-5e, a polar see-saw with record-breaking (anthropogenic only, not paleo) Arctic melt and record Antarctic sea-ice the math comes face to face with “We thus estimate interglacial duration as the interval between the terminal occurrence of bipolar-seesaw variability and 3 kyr before its first major reactivation.”

    The variable “major reactivation” operative given our paucity of concise late Holocene records. Did we just see it happen? Is that what we are seeing at the poles? Was the LIA a LEAP (Late Eemian Aridity Pulse)? Did the Holocene end 3kyrs ago based on this year’s polar ice?

    Regardless, there is all this disquieting activity not going on with the quiet sun. The PDO negative, the AMDO will follow when? The 20th century grand solar maximum dwarfed by the hypsithermal, Roman, Minoan, and Medieval decaying thermal spikes.

    Fact is, we don’t really know when this one will end. But to use the popular vernacular of the Post-Literate Age we “could” “might” “possibly” “irreversibly” descend into the next glacial or experience who knows how many normal natural end extreme interglacial thermal spikes.

    It’s the gaining of the perspective that a chaotic, possibly stochastic yet rhythmic system as we presently observe HAS contained such end extreme interglacial noise that our current prognosticated anthropogenic “signal(s)” will be all but impossible to discern.

    The end-game being simply this. CO2 had better be the heathen devil gas it is made out to be. If you can think of another way to avoid the slide into a glacial I am sure the geoengineers will (eventually) be all ears. Not that CO2, already in the throes of IR saturation, provides any sentient comfort. I just can’t see how more plant food can hurt at a possible/probable end extreme interglacial. This from someone that has spent over half his life cleaning up our worst toxic cocktails.

    The way I see it, at a possible/probable end extreme interglacial, every penny not spent on fusion research will likely turn out to be a penny wasted. And we might just have to pass a planetary law prescribing the precise siting and revisable classification system for weather stations (urban sprawl et al), no mucking about with the data, and if you do you WILL give up every detail. The penalties worse than we thought…….

    It “could” be just this simple: how many tipping points constitute glacial inception?

    Meanwhile, enjoy the end-extreme-interglacial! While it lasts………………..

  66. gymnosperm says:

    dscott says:

    October 3, 2012 at 12:32 pm

    “EVERY interglacial ends at the down swing of the obliquity cycle when it passes 23.5 degrees. NO EXCEPTIONS!!!!!”

    +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

    Very interesting, but I stare at a Wickipedia graphic from time to time that seems to my eyecrometer to show interglacials ending in every concievable up or down swing in obliquity.

  67. Joachim Seifert says:

    To William: Our paper, available already this month:
    http://www/knowledgeminer.eu/eoo_paper.html
    includes the entire Holocene plus a 500 year’s extention into the
    future. The end of the Holocene can clearly be seen, we all have
    to only agree on which is the global GMT-temperature level, we all
    consider as sufficiently cold/or the END turning point is reached, to
    name this point of time the “end point of the Holocene” …..
    We will offer our paper soon to Anthony for your inspection…
    .Cheers JS

  68. beng says:

    ****
    William McClenney says:
    October 3, 2012 at 8:18 pm
    ****

    William, thanks. Question: Not sure of the specifics of the 65N insolation values (W/m2). Is this an instantaneous value (like noon at summer solstice), or an integrated value? If one could integrate the solar input over a 24hr period @65N summer solstice, then that would include the effect of obliquity (tilt angle) and make better comparisons/correlations possible. Or integrate insolation over an entire melt-season period.

    They didn’t mention eccentricity. I’m not convinced that it doesn’t need considering.

  69. beng says:

    ****
    William McClenney says:
    October 3, 2012 at 8:18 pm

    The variable “major reactivation” operative given our paucity of concise late Holocene records. Did we just see it happen? Is that what we are seeing at the poles? Was the LIA a LEAP (Late Eemian Aridity Pulse)? Did the Holocene end 3kyrs ago based on this year’s polar ice?
    ****

    Yeah, but now is the opposite of the bipolar-seesaw, defined as an Arctic cooling/Antarctic warming. :) What to make of that?

  70. dscott says:

    Very interesting, but I stare at a Wickipedia graphic from time to time that seems to my eyecrometer to show interglacials ending in every concievable up or down swing in obliquity.

    Yes, it is difficult to eyeball unless you scale the various obliquity, Vostoc and Antarctic Ice core charts over each other. You have to do some stretching and compacting of the graphics to line up the time lines on the x axis. That’s not the accuracy one likes unless you have the actual data files that would allow you to overlay all three data sets to produce a fairly accurate graphic. This is why I pose the question to the scientific types who have access to the data files. Add in the known sea levels and you will have a reasonably good means of prediction.

  71. William McClenney says:

    Joachim Seifert says:
    October 4, 2012 at 8:13 am

    http://www.www.com/?f

    If I click on the link you provided I end up at the address above ???

    Please check the link Joachim, I would like to read your paper.

    Thanks!

  72. William McClenney says:

    beng says:
    October 4, 2012 at 9:48 am

    “……(like noon at summer solstice)”

    Exactly.

  73. Joachim Seifert says:

    William, excuse…..one dot after www was wrong….therefore:
    http://www.knowledgeminer.eu/eoo_paper.html
    this time, it should work. We offer a short summary; please look
    for the long summary, which gives you a good idea. We took
    care to even explain to the layman. The paper itself has good
    Holocene graphs. It will be on-line within a few days…
    Have a look, it is all original, new knowledge…Cheers, JS.

  74. beng says:

    ****
    William McClenney says:
    October 3, 2012 at 8:18 pm

    The variable “major reactivation” operative given our paucity of concise late Holocene records. Did we just see it happen? Is that what we are seeing at the poles? Was the LIA a LEAP (Late Eemian Aridity Pulse)? Did the Holocene end 3kyrs ago based on this year’s polar ice?
    ****

    That might be true if the LIA was a seesaw event — caused Antarctica to warm. The ice-core graphs of Antarctica I have don’t have the scale/resolution to tell, but I think other proxies indicate the SH cooled. Still, the current polar sea-ice seesaw is interesting…

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