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……
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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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
These are actually the type questions that climate research was originally justified with and funded for: predicting the next, presumably inevitable, Ice Age.
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.
If it ain’t falsifiable then it ain’t science.
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.
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.
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.
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.
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.”
Agree. Also, the writer, given the above writing sample, could, with some encouragement, “step away from” the comma. Way over-used.
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.
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.
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?
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.
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”.
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:
And the answer to that is: no.
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!
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.
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
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.
“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??
“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 +).
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.
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.
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.
Recommend reading this paper carefully. Alot of good info. And for those thinking all interglacials last only ~10kyrs, think again.