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)
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
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.
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.
“Will this wind, be so mighty, as to lay low, the mountains. of the earrrrrth?”
No!
early snowfall in Iceland I read. Only weather of course. But they are already digging sheep out.
http://youtu.be/mVEXreQirrk
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.
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.
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.
Admin: The link did not pop up, why?
Maybe because of the brackets? Again without brackets:
http://www.knowledgeminer.eu/eoo_paper.html
Thanks JS
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
@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)
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
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
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.
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.
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.
“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 ?
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.
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
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.
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.
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).
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.
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.
The Holocene is around 16,000 years old.
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!
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.