The Antithesis

You know, in science, there was once this thing we called the Theory of Multiple Working Hypotheses. Anathema (a formal ecclesiastical curse accompanied by excommunication) in modern climate science. So, in juxtaposition to the hypothesis of future global climate disruption from CO2, a scientist might well consider an antithesis or two in order to maintain ones objectivity.

One such antithesis, which happens to be a long running debate in paleoclimate science, concerns the end Holocene. Or just how long the present interglacial will last.

Looking at orbital mechanics and model results, Loutre and Berger (2003) in a landmark paper (meaning a widely quoted and discussed paper) for the time predicted that the current interglacial, the Holocene, might very well last another 50,000 years, particularly if CO2 were factored in. This would make the Holocene the longest lived interglacial since the onset of the Northern Hemisphere Glaciations some 2.8 million years ago. Five of the last 6 interglacials have each lasted about half of a precession cycle. The precession cycle varies from 19-23k years, and we are at the 23kyr part of the range now, making 11,500 years half, which is also the present age of the Holocene.

Which is why this discussion has relevance.

But what about that 6th interglacial, the one that wasn’t on the half-precessional “clock”. That would be MIS-11 (or the Holsteinian) which according to the most recently published estimate may have lasted on the order of 20-22kyrs, with the longest estimate ranging up to 32kyrs.

Loutre and Berger’s 2003 paper was soon followed by another landmark paper by Lisieki and Raymo (Oceanography, 2005), an exhaustive look at 57 globally distributed deep Ocean Drilling Project (and other) cores (Figure 1), which stated:

Recent research has focused on MIS 11 as a possible analog for the present interglacial [e.g., Loutre and Berger, 2003; EPICA community members, 2004] because both occur during times of low eccentricity. The LR04 age model establishes that MIS 11 spans two precession cycles, with 18O values below 3.6o/oo for 20 kyr, from 398-418 ka. In comparison, stages 9 and 5 remained below 3.6o/oo for 13 and 12 kyr, respectively, and the Holocene interglacial has lasted 11 kyr so far. In the LR04 age model, the average LSR of 29 sites is the same from 398-418 ka as from 250-650 ka; consequently, stage 11 is unlikely to be artificially stretched. However, the June 21 insolation minimum at 65N during MIS 11 is only 489 W/m2, much less pronounced than the present minimum of 474 W/m2. In addition, current insolation values are not predicted to return to the high values of late MIS 11 for another 65 kyr. We propose that this effectively precludes a ‘double precession-cycle’ interglacial [e.g., Raymo, 1997] in the Holocene without human influence.”

 

Figure 1. The past 5 million years of climate from 57 globally distributed sediment cores. (a general definition of an interglacial since the MPT is the oxygen 18/oxygen 16 isotope ratio must drop to 3.6 parts per mil)

To bring this discussion up to date, Tzedakis (Figure 2, his figure 3), in perhaps the most open peer review process currently being practiced in the world today (The European Geosciences Union website Climate of the Past Discussions) published a quite thorough examination of the state of the science related to the two most recent interglacials, which like the present one, the Holocene (or MIS-1) is compared to MIS-19 and MIS-11, the other two interglacials which have occurred since the Mid Pleistocene Transition (MPT) and also occurred at eccentricity minimums. Since its initial publication in 2009, and its republication after the open online peer review process again in March of this year (2010), this paper is now also considered a landmark review of the state of paleoclimate science. In it he also considers Ruddiman’s Early Anthropogenic Hypothesis, with Ruddiman a part of the online review. Tzedakis’ concluding remarks are enlightening:

“On balance, what emerges is that projections on the natural duration of the current interglacial depend on the choice of analogue, while corroboration or refutation of the “early anthropogenic hypothesis” on the basis of comparisons with earlier interglacials remains irritatingly inconclusive.”

Figure 2. Tzedakis (2010) comparing the Holocene with the previous 4 interglacials.

An astute reader might have gleaned that even on things which have happened, the science is not that particularly well settled. Which makes consideration of the science being settled on things which have not yet happened dubious at best.

As we move further towards the construction of the antithetic argument, we will take a closer look at the post-MPT end interglacials and the last glacial for some clues.

Higher resolution proxy studies from many parts of the planet suggest that the end interglacials may be quite the wild climate ride from the perspective of global climate disruption.

Boettger, et al (Quaternary International 207 [2009] 137–144) abstract it:

“In terrestrial records from Central and Eastern Europe the end of the Last Interglacial seems to be characterized by evident climatic and environmental instabilities recorded by geochemical and vegetation indicators. The transition (MIS 5e/5d) from the Last Interglacial (Eemian, Mikulino) to the Early Last Glacial (Early Weichselian, Early Valdai) is marked by at least two warming events as observed in geochemical data on the lake sediment profiles of Central (Gro¨bern, Neumark–Nord, Klinge) and of Eastern Europe (Ples). Results of palynological studies of all these sequences indicate simultaneously a strong increase of environmental oscillations during the very end of the Last Interglacial and the beginning of the Last Glaciation. This paper discusses possible correlations of these events between regions in Central and Eastern Europe. The pronounced climate and environment instability during the interglacial/glacial transition could be consistent with the assumption that it is about a natural phenomenon, characteristic for transitional stages. Taking into consideration that currently observed ‘‘human-induced’’ global warming coincides with the natural trend to cooling, the study of such transitional stages is important for understanding the underlying processes of the climate changes.”

Hearty and Neumann (Quaternary Science Reviews 20 [2001] 1881–1895) abstracting their work in the Bahamas state:

“The geology of the Last Interglaciation (sensu stricto, marine isotope substage (MIS) 5e) in the Bahamas records the nature of sea level and climate change. After a period of quasi-stability for most of the interglaciation, during which reefs grew to +2.5 m, sea level rose rapidly at the end of the period, incising notches in older limestone. After brief stillstands at +6 and perhaps +8.5 m, sea level fell with apparent speed to the MIS 5d lowstand and much cooler climatic conditions. It was during this regression from the MIS 5e highstand that the North Atlantic suffered an oceanographic ‘‘reorganization’’ about 118.73 ka ago. During this same interval, massive dune-building greatly enlarged the Bahama Islands. Giant waves reshaped exposed lowlands into chevron-shaped beach ridges, ran up on older coastal ridges, and also broke off and threw megaboulders onto and over 20 m-high cliffs. The oolitic rocks recording these features yield concordant whole-rock amino acid ratios across the archipelago. Whether or not the Last Interglaciation serves as an appropriate analog for our ‘‘greenhouse’’ world, it nonetheless reveals the intricate details of climatic transitions between warm interglaciations and near glacial conditions.”

See Figure 3 (also figure 3 in their study)

Figure 3. Rapid Sea Level Spike at the end of MIS-5, the Eemian.

and Figure 4 (figure 5 in their study).

Figure 4. The MIS-5e notch (photo A) and modern notch (photo B) (Hearty and Neumann, 2001, figure 5).

The picture which emerges is that the post-MPT end interglacials appear to be populated with dramatic, abrupt global climate disruptions which appear to have occurred on decadal to centennial time scales. Given that the Holocene, one of at least 3, perhaps 4 post-MPT “extreme” interglacials, may not be immune to this repetitive phenomena, and as it is half a precession cycle old now, and perhaps unlikely to grow that much older, this could very well be the natural climate “noise” from which we must discern our anthropogenic “signal” from.

If we take a stroll between this interglacial and the last one back, the Eemian, we find in the Greenland ice cores that there were 24 Dansgaard-Oeschger oscillations (Figure 5, originally figure 1. Sole et al, 2007), or abrupt warmings that occurred from just a few years to mere decades that average between 8-10C rises (D-O 19 scored 16C). The nominal difference between earth’s cold (glacial) and warm (interglacial) states being on the order of 20C. D-O events average 1470 years, the range being 1-4kyrs.

Figure 5. Dansgaard-Oeschger oscillations with their cycle designations. (Sole et al, 2007)

Sole, Turiel and Llebot writing in Physics Letters A (366 [2007] 184–189) identified three classes of D-O oscillations in the Greenland GISP2 ice cores A (brief), B (medium) and C (long), reflecting the speed at which the warming relaxes back to the cold glacial state:

“In this work ice-core CO2 time evolution in the period going from 20 to 60 kyr BP [15] has been qualitatively compared to our temperature cycles, according to the class they belong to. It can be observed in Fig. 6 that class A cycles are completely unrelated to changes in CO2 concentration. We have observed some correlation between B and C cycles and CO2 concentration, but of the opposite sign to the one expected: maxima in atmospheric CO2 concentration tend to correspond to the middle part or the end the cooling period. The role of CO2 in the oscillation phenomena seems to be more related to extend the duration of the cooling phase than to trigger warming. This could explain why cycles not coincident in time with maxima of CO2 (A cycles) rapidly decay back to the cold state. ”

“Nor CO2 concentration either the astronomical cycle change the way in which the warming phase takes place. The coincidence in this phase is strong among all the characterized cycles; also, we have been able to recognize the presence of a similar warming phase in the early stages of the transition from glacial to interglacial age. Our analysis of the warming phase seems to indicate a universal triggering mechanism, what has been related with the possible existence of stochastic resonance [1,13, 21]. It has also been argued that a possible cause for the repetitive sequence of D/O events could be found in the change in the thermohaline Atlantic circulation [2,8,22,25]. However, a cause for this regular arrangement of cycles, together with a justification on the abruptness of the warming phase, is still absent in the scientific literature.”

Figure 6. Sole et al (2007) D/O oscillation classes.

In their work, at least 13 of the 24 D-O oscillations (indeed other workers suggest the same for them all), CO2 was not the agent provocateur of the warmings but served to ameliorate the relaxation back to the cold glacial state, something which might have import whenever we finally do reach the end Holocene. Instead of triggering the abrupt warmings it appears to function as somewhat of a climate “security blanket”, if you will.

Therefore in constructing the antithesis, and taking into consideration the precautionary principle, we are left to ponder if reducing CO2’s concentration in the late Holocene atmosphere might actually be the wrong thing to do.

The possibility consequently exists that at perhaps precisely the right moment near the end-Holocene, the latest iteration of the genus Homo unwittingly stumbled on the correct atmospheric GHG recipe to perhaps ease or delay the transition into the next glacial. Under the antithesis “Skeptics” and “Warmists” thus find themselves on the mutual, chaotic climate ground where the efficacy of CO2 as a GHG had better be right.

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The second sentence of the post is:
Anathema (a formal ecclesiastical curse accompanied by excommunication) in modern climate science.
Removing the parenthetical clause yields:
Anathema in modern climate science.
Where is the verb that could help me understand the point? What is the anathema? Do you mean that alternate hypotheses are anathemas to the Warmists?

Newt Love says:
December 30, 2010 at 10:08 am
“The second sentence of the post is:
Anathema (a formal ecclesiastical curse accompanied by excommunication) in modern climate science.
Removing the parenthetical clause yields:
Anathema in modern climate science.
Where is the verb that could help me understand the point? What is the anathema? Do you mean that alternate hypotheses are anathemas to the Warmists?”
I’d assumed that the previous period should’ve been a hyphen, but I do tend to overuse such punctuation.

James Sexton

Therefore in constructing the antithesis, and taking into consideration the precautionary principle, we are left to ponder if reducing CO2’s concentration in the late Holocene atmosphere might actually be the wrong thing to do.
=========================================================
One of the many skeptical perspectives is that warming is a good thing. Many of us have been saying this for years. I very seriously doubt ACO2 emissions have much to do with anything, but if it were to be a cause of warmth, we should do more of it.

Jeroen B.

A VERY thought provoking article. Thank you, this certainly was one worth reading. (even if some of the jargon is a bit beyond my comprehension)
@Newt: Any hypothesis (or evidence even!) that disagrees with AGW is an anathema to the Warmista’s – after all, such theories would undermine their funding and alarmism.

erik sloneker

This article is a good illustration of why geologists, by and large, have not been invited into the CAGW discussion. An understanding of past climate variations inconveniences those who claim current warming is CO2 induced and unprecedented.

Tom in Florida

Two other conditions must occur to create the interglacials. Obliquity must be approaching maximum and perihelion must be in NH summer. These conditions all lined up about 10 -12000 years ago. Back of the envelope calculations indicate this condition, where all come together, occurs about every 100,000 years.

Ray Donahue

Anathema is a noun. Poor punctuation but the meaning is clear.

Charlie

Sorry, my brain gave up after only a couple of sentences.
The first paragraph doesn’t make any sense.

etudiant

An excellent post!
It highlights the science that motivates the better informed AGW zealots.
It is a fact that the global climate has repeatedly flipped by 10 degrees or more on a dime, in a few decades or less, maybe much less.
We do not know why, but we do know it has happened often in relatively recent times, geologically speaking..
The AGW crowd, imo, knows this and is terrified that such an excursion could result from our GHG emissions. The atmosphere is so poorly understood that it is equally possible that the result would be a sharp drop in global temperature, but that is not the propaganda path they chose.
The heart of their message is that this is the only environment we have, it is pretty good, but it is pretty unstable, so let’s not mess with it. Lots of other elements will anyways.
I for one would see this as a credible message.Too bad it has gotten lost in the scuffle.

It’s curious how scientists have clung to the reductionist view that carbon and only carbon is a factor in global warming. Possible effects of the precessional cycle, activity on the sun’s surface and other possibly very relevant factors such as deforestation which only began about 5000 years ago don’t seem to attract any interest.
But then I have always suspected scientists don’y much care for the complexity of problems that do not offer prospects of immediate and generous research grants. I mean who is going to care about a problem that needs 23k years research?

Anything is possible

Why is it that the biggest feedback mechanism of all – the changes in surface topography which are an inevitable consequence of the building and disintegration of continental ice sheets – gets nary a mention in the discussion of glacial/inter-glacial cycles?
At the height of the last glaciation, the ice sheets over North America and Europe were 3-4km thick. Simply by applying Environmental Lapse Rates (ELR), we can deduce that the surface temperatures in these regions would have been 20-25C cooler than today, merely because of their increased height above sea level.
Additionally, when an area is covered with ice, it is subject to both erosion – vast quantities of material are transported out of the region – and glacio-isostatic depression, meaning that when the ice is removed, the topography would be considerably different – and different in a way that would serve to ameliorate subsequent surface temperatures – than before glaciation took place.
I’m sorry, but I don’t see how any discussion of how the Earth’s climate switches between glacial and inter-glacial cycles can exclude this effect and hope to tell the full story.

Bill Illis

If you look at the forecast June insolation at 65N, it is going to decline (very, very slightly, just a few watts/m2) from today for another 1,000 years before starting back up again.
http://3.bp.blogspot.com/_nOY5jaKJXHM/S0pMeoX0DYI/AAAAAAAAAl8/ficHeOA8Jdw/s1600-h/insolation+10k.jpg
The magic insolation number is something like 450 to 470 watts/m2 (the summer sunshine at about 9:00 am if you live at 40N, the centre latitude of the US) so this is high enough to melt all the snow during the summer in the far north (especially since there are more hours of it in the summer). The forecast shows it staying above the 480 watts/m2 at the peak low period in about 1,000 years.
If you extend this forecast out now for 200,000 years, it looks like we do not fall below the magic 470 watts/m2 for 50,000 years, 130,000 years or even 170,000 years. So, this interglacial should be by far the longest one since the ice ages started.
http://2.bp.blogspot.com/_nOY5jaKJXHM/S0pMWh0jC_I/AAAAAAAAAl0/jFrzGsHsWEE/s1600-h/insolation+200k.jpg

tty

It might be worth noting that the sudden sea-level spike at the end of MIS 5e (and a supposedly even higher at about 15 meter near the end of MIS 11) are extremely dubious.
Neither is visible in the isotope record and the interpretation of features in Bahamas and Bermuda as indicating those extremely high sea levels is controversal, to put things mildly. They are not based on indisputable coastline features, and isolated finds and patches of marine deposits at high level mean very little in areas where hurricanes are common.
Even the endlessly repeated figure of 6 meter sea level rise during the last interglacial is very doubtful. The best data from the most tectonically stable coasts such as the Gawler craton and the Coorong coastal plain in Australia makes a figure of about 2 meters for both MIS 5e and MIS 11 more likely.
The reason for the popularity of the high sea-level figures is that they support the catastrophy scenarios about collapses of the Greenland and West Antarctic ice caps. As a matter of fact the 6 meter figure seems to have been originally postulated based on how much the sea-level should rise if the WAIS collapsed!
That all drill-holes in Greenland (including even the small Renland icecap) has found ice of last interglacial age is simply ignored, as is the evidence from the AND-1B drilling in the Ross Sea that shows that the ice in the Ross embayment has never been appreciably smaller than at present since the MIS 31 “super-interglacial” more than a million years ago.
Here is a couple of more interesting conundrums in the Pleistocene record.
MIS 13 is a very “wimpy” interglacial in the marine isotope record when apparently a large proportion of glacial ice never melted. However in the continental record in Eurasia (loess profiles and animal and plant fossils) it was a very major interglacial, quite possibly the longest and warmest of all. The only reasonable explanation seems to be that it was an “unipolar” interglacial when much of the ice in Antarctica never melted. However nobody has a clue how this would work.
Neither does anybody really know why glacial cycles shifted from 40,000 year length to 100,000 year length about a million years ago. This, the Mid Pleistocene Transition (MPT) was a major shift that did not only affect the length of ice-ages, but also had major effect on a multitude of other things. For example it seems that really large coral reefs did not exist before the MPT.

Jared

Could James Hansen do this experiment for me?
– Make 7 jars with exactly 10,000 molecules in each and make it a sample of 1900 air with 3 molecules of CO2 out of the 10,000 molecules.
– Leave one jar as a Constant
– Take jar #2 and take out a Methane Molecule and add a CO2 molecule in it’s place (today’s CO2 content)
– Take jar #3 and take out 4 Methane Molecules and add 4 CO2 molecules in it’s place (doubling of CO2)
– Take jar #4 and take out an Oxygen Molecule and add a CO2 molecule in it’s place (today’s CO2 content)
– Take jar #5 and take out 4 Oxygen Molecules and add 4 CO2 molecules in it’s place (doubling of CO2)
– Take jar #6 and take out a Hydrogen Molecule and add a CO2 molecule in it’s place (today’s CO2 content)
– Take jar #7 and take out 4 Hydrogen Molecules and add 4 CO2 molecules in it’s place (doubling of CO2)
– Which jar gets the warmest? Oxygen replaced by CO2? Hydrogen replaced by CO2? Or Methane replaced by CO2? And which one of these is closest to the type of warming we are getting.
Do not pump in CO2 to unrealistic conditions. If going from 3 CO2 molecules out of 10,000 to 4 CO2 Molecules out of 10,000 is so horrible as you claim, then your test should be horrific.
Please Jimmy do the experiment and report back.

Good to see some geoscience oriented MWH analysis applied to such a highly complex subject. Something I have been beating the drum for since my undergraduate days. (A long, long time ago) Lots of good information much new to me so I will need to think about it and probably spend some time at the library.
Not only do we have more questions then answers generated but you have provided a good example of what we do not know. Knowing what we do not know is ultimately the most important part of any scientific understanding of anything. To be a practitioner of the Philosophy of Science is to approach the world with a questioning and skeptical mind set. The only settled part of anything is the understanding that nothing ever is. The only absolute is their probably aren’t any.

Doug in Seattle

It would be the ultimate climate irony if lowering CO2 forced an ice age. This would of course only be possible if CO2 is the great powerful heat trapping gas it is reputed to be by the alarmists – something that has yet to be established.

Newt Love – In normal usage of the English language, sentences (the set of words between full stops), don’t always contain verbs. The trick (if I can use that word here) is to interpret from context. In such cases, either the meaning is obvious anyway, or it typically relates to the previous sentence or last part of same. What you have done in your comment is to drop the previous sentence, thus leaving the cited sentence without context. Not clever.
Putting it back in, we get: You know, in science, there was once this thing we called the Theory of Multiple Working Hypotheses. Anathema in modern climate science. Clearly, what is being said is that the Theory of Multiple Working Hypotheses is anathema in modern climate science.
I have no difficulty in accepting that the way it was expressed, while maybe not grammatically perfect, was at least as effective and economical as, for example:
“You know, in science, there was once this thing we called the Theory of Multiple Working Hypotheses. The Theory of Multiple Working Hypotheses is anathema in modern climate science.”
or:
“You know, in science, there was once this thing we called the Theory of Multiple Working Hypotheses, which is anathema in modern climate science.”
particularly as the author did include the parenthetical clause.
To me, English as she is is fascinating. There is no correct pronunciation or spelling of any word (lexicographers simply record actual usage), and new words appear in the language without authority while other words disappear without any official pronouncement (NPI). Grammar similarly. Yet one of the worst things that schools can do is fail to teach correct spelling, pronunciation and grammar. So there is no correct form, yet the correct form must be taught. A paradox indeed.

HybridWeb

Of course we should have realized it; there is good science being practiced in the climate science community.
Perhaps it should be the focus of climate science to better clarify just how long we’ve got before descending into another ice age. Anything else (CAGW, for instance) is a major distraction from this goal.

Jared says:
December 30, 2010 at 11:15 am
Could James Hansen do this experiment for me?
JH: Do you mean a Model?. Please clarify: What the heck “experiment” is?

John from CA

Great post, fascinating, confusing, and disturbing all in one.
“It was during this regression from the MIS 5e highstand that the North Atlantic suffered an oceanographic ‘‘reorganization’’ about 11873 ka ago. During this same interval, massive dune-building greatly enlarged the Bahama Islands. Giant waves reshaped exposed lowlands into chevron-shaped beach ridges, ran up on older coastal ridges, and also broke off and threw megaboulders onto and over 20 m-high cliffs.”
from prior studies:
14k BP we had human migration across the Bering land bridge and hunting settlements along Eastern Siberia and Alaska.
As the Oceans rose, Bering Strait is 49 meters deep at its lowest and the Oceans fell 120-150 meters during the glacial, the Strait reopened and altered Atlantic currents. This reopening gradually occurred ˜12-10k BP.
The Bahamas are in hurricane alley but hurricanes aren’t capable of tossing “megaboulders onto and over 20 m-high cliffs”. Tidal waves from calving east coast glaciers? The ice sheets stopped in and around the NYC area. The scale of ocean displacement required to create tidal waves on this scale seems unlikely given east coast shoreline depth.
About the only thing that seems to makes sense within the time frames mentioned in the post is tsunami as the crust rebounded or icebergs crashing into the islands. I can easily buy the massive dune-building but the tossing “megaboulders onto and over 20 m-high cliffs” is pretty hard to explain.

Darkinbad the Brightdayler

The Antithesis is possibly the most significant posting on WUWT since I’ve been visiting here.
A real eye opener

bubbagyro

Anything is possible says:
December 30, 2010 at 11:08 am
You mistake cause and effect—an epidemic these days.
Jared says:
December 30, 2010 at 11:15 am
10,000 molecules in a jar would produce a vacuum lower than anywhere now known in the universe, and a much lower vacuum than man is able to generate in the laboratory (at the size of a jar).

jorgekafkazar

aNATHema is both a noun (curse) and an adjective (accursed). [If I remember my Jesuit schooling correctly, there was also a word, anaTHEma, which meant the opposite, or something visibly offered to God.] The origins of the word are complex.
http://www.ourladyswarriors.org/dissent/defnanat.htm

Brian H

James, Bill;
From your lips(es) to the Climate God(s)’s ears! More Warming = More Life. More Cooling = More Death!
tty;
Yes, cherry-picking seems to relate to more than trendline start-stop dates, doesn’t it?

Brian H

jorge;
One might speculate how best to verb-ize “anathema”. Anathemate? Anathmetize?
😉

JudyW

Very interesting. Most studies cite the beginning of this interglacial period as starting at the end of the Younger Dryas cooling -11,550+ years ago. Other studies and papers indicate the end of the last interglacial occured prior to the Younger Dryas period. See Figure 2. Climate changes in the past 17,000 years for the GISP2 Greenland ice core.
http://www.globalresearch.ca/index.php?context=va&aid=10783

Jared

bubbagyro,
I think the point flew right over your head.
3 out of every 10,000 molecules in 1900 where CO2. Today 4 out of every 10,000 molecules are CO2. And they say it’s caused horrific things to planet Earth.
Which molecule has CO2 been replacing? H2, O2, CH4, H2O, etc

Dave Springer

So the $64,000 question remains: Is our children learning what snow is?

Anything is possible

bubbagyro says:
December 30, 2010 at 12:04 pm
Anything is possible says:
December 30, 2010 at 11:08 am
You mistake cause and effect—an epidemic these days.
____________________________________________________________
Why do the two have to be mutually exclusive?
Cannot something that is an effect of changing climate today wind up as being a cause of (non)-changing climate tomorrow?
That would certainly help to explain why the science is so darned complicated……

R. de Haan

“The possibility consequently exists that at perhaps precisely the right moment near the end-Holocene, the latest iteration of the genus Homo unwittingly stumbled on the correct atmospheric GHG recipe to perhaps ease or delay the transition into the next glacial. Under the antithesis
“Skeptics” and “Warmists” thus find themselves on the mutual, chaotic climate ground where the efficacy of CO2 as a GHG had better be right”.
You must be a great lover of fairy tails.

Dave Springer

Jared says:
December 30, 2010 at 11:15 am
re; jar with 10,000 molecules in it
The best vacuum attainable in a lab still has 100 particles per cubic centimeter.
You might want to change the specification for your experiment from 10,000 molecules to some practical number like 10,000,000,000,000. Or better yet specify partial pressures of the different gases.

bubbagyro

Brian H says:
December 30, 2010 at 12:33 pm
The existing word is anathematize.

anna v

Brian H says:
December 30, 2010 at 12:33 pm

jorge;
One might speculate how best to verb-ize “anathema”. Anathemate? Anathmetize?
😉

In greek it is “anathematizo” so it should be “anathematize”.

RockyRoad

Where I live, another Ice Age like the last would mean only one month–July–would have average lows above freezing. And that would be by a measly 1 or 2 degrees F. How could anybody expect to grow ANYTHING with a growing season measured in days or weeks, rather than months? They flat out couldn’t. And as horendous as the prospects of the next Ice Age might be, I believe it has a far higher probability of happening than any catastrophic event the AGW people can dream up.

phlogiston

Bill Illis says:
December 30, 2010 at 11:09 am
On what basis are we so sure that insolation by itself is the only factor in interglacial termination? Is insolation the new CO2? I thought that climate was a complex system – maybe this is naive (its certainly politically incorrect).

John F. Hultquist

Thanks for this post. Lots of interesting information.
~ ~ ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~
From the 3rd paragraph: since the onset of the Northern Hemisphere Glaciations some 2.8 million years ago.
The Isthmus of Panama came into being at about 3 million years ago. The timing regarding the information in this post follows the closure of the “Central American Seaway”, so some may want to read about it.
Without getting into the argument of how it came to be, consider the Isthmus of Panama; http://en.wikipedia.org/wiki/Isthmus_of_Panama
Before that land came to be there was a “Central American Seaway” between the now-Atlantic and the now-Pacific Oceans. See this site for an explanation, maps, and a discussion of why this is important:
http://www.whoi.edu/oceanus/viewArticle.do?id=2508
Convergence of the of the Pacific, North American, and Caribbean tectonic plates was sufficiently well along by about 5 million years ago and the closure was likely in place about 3 million years ago.
The title of the last linked-to paper is:
How the Isthmus of Panama Put Ice in the Arctic:
Drifting continents open and close gateways between oceans and shift Earth’s climate

Here is a quote: “ The gradual shoaling of the Central American Seaway began to restrict the exchange of water between the Pacific and Atlantic, and their salinities diverged. . . . As a result of the Seaway closure, the Gulf Stream intensified. It transported more warm, salty water masses to high northern latitudes, where Arctic winds cooled them until they became dense enough to sink to the ocean floor.
This is an informative report with nice graphics.
———-
At 11:08 Anything is possible says: . . . the changes in surface topography which are an inevitable consequence of the building and disintegration of continental ice sheets . . .
I’ll restate this as Earth is dynamic. Some of the research dollars being thrown at the AGW concept might better be applied toward a better understanding of the transitions described in the McClenney Antithesis.

John F. Hultquist

Doug in Seattle says:
December 30, 2010 at 11:19 am
It would be the ultimate climate irony . . .

As the effect of CO2 is logarithmic one gets a stronger response from the removal than one does from the addition but in the opposite direction.

Vince Causey

Bill Illis,
“If you extend this forecast out now for 200,000 years, it looks like we do not fall below the magic 470 watts/m2 for 50,000 years, 130,000 years or even 170,000 years. So, this interglacial should be by far the longest one since the ice ages started.”
Insolation is not only the product of orbital configurations, but also of albedo, which is in great part a dependent on clouds. I think it optimistic to declare the longevity of our interglacial on orbitals alone.

[banzai voice]
It’s the great glaciation guesswork gamble! Will we freeze our fundaments off in:
a) 500 years?
b)1500 years?
c)50000 years?
Place bets NOW!!!
Great article by the way.

R. Gates

Amazingly excellent post…thank you!

John Whitman

William McClenney,
I found your article excellent in providing perspective on the natural variation in the current natural climate processes that could show an ending of the current interglacial (our beloved Holocene).
AGW theory has some significant competing hypotheses to contend with. : )
John

cal

I found the charts in this post really interesting. It is the clearest picture I have seen of how the ice ages have evolved. Looking at Fig 1 the world’s climate clearly started to cool about 3 million years ago but maintained its sinusoidal pattern with a 41K year cycle. Then about 1 million years ago there was a sudden and (so far) irreversable change to a 100K cycles with each one characterised by a slow cooling and then a sudden brief warming.
However I have some doubt about the 100K cycles. It seems that in counting the peaks and troughs in the last million years some of them have been ignored. When I count them all I find that there are about 50 reversals in every million years just the same as before. It looks like the underlying forcing is still there. Superimposed on this is a continuation of the overall cooling and an additional sudden and brief warming every 100K which I personally think looks like some sort of terrestial resonance effect linked to the ice formation. That is an overshoot and bounce back.
It seems bizarre to me that some are predicting that the current warm period will last for another 50000 years when none of the last 10 cycles have anything like this pattern. They appear to use Milankovitch type arguments. However everyone knows that whilst the Milankovitch patterns fit the data the mechanisms when translated to changes in insolation don’t make sense. Clearly the mechanisms are not yet understood so how can you make predictions. I’m for betting that history will repeat itself and that it is going to get colder pretty soon.

Fascinating.
From 5 million years ago to 1 million years ago, warm periods were at the frequency of one every 40,000 years or so. From 1 million years ago up to the present time, the frequency has been one every 100,000 years or so. Even more interesting is the very steady descent into overall cooling these last 5 million years. The Ice Age threshold was only regularly crossed from about 2.5 million years ago and since then things have got steadily worse (=colder, with bigger swings) although things might, just might have bottomed out.
I had to redo the Lisieki-Raymo chart and put it all on one line, to see all this clearly.

Lots of good stuff here that I’ll have to think about. Always good to see the geological perspective on climate change. Thanks for a very thought-provoking post.
Best for 2011, Pete Tillman
Consulting Geologist, Arizona and New Mexico (USA)

JimF

@Brian H says:
December 30, 2010 at 12:33 pm
The verbal form is:
anathematize |əˈnaθəməˌtīz|
verb [ trans. ]
curse; condemn : she anathematized Tom as the despoiler of a helpless widow.
ORIGIN mid 16th cent.: from French anathématiser, from Latin anathematizare, from Greek anathematizein, from anathema (see anathema ).

Gary Pearse

Wonderful stuff! Geology is the beautiful science. I think it is clear that the problem with modern climate science is that it was invented by astrophysicists who were ignorant of the venerable and considerable body of paleoclimatological work. Much of the past 30 years of modern climatology has been spent in fighting a rearguard action against prior paleoclimatological findings as they (the physicists) inevitably came to discover their existence and the inconvenient story they presented. They even put down their telescopes which were trained on Venus and took up the tools of the paleoclimatologist to re-jigger that science. The craziness of physicists studying tree rings! Geologists, who tend to be quiet genial types in the main, first off didn’t bother to join the discussion, busy as they always are, and ultimately were essentially shut out of the mainstream of a science to which they had the most to offer. Thankfully, for the wellbeing of humankind and other species put at risk by armageddon zealots, geologists are coming forward in the authoritative and gentleperson manner of their kind to quash the expensive silliness that has been let rage on far too long.

John from CA

John from CA says:
December 30, 2010 at 11:53 am
=====
Sorry, I was wrong — I was referring to 25kyr BP to present (though I’m still having trouble with the megaboulder tossing).
Based on the following study (see figure 1), projected Pacific sea level at the Bering Strait ˜120kyr BP was above current levels. It seems reasonable to conclude that Atlantic Sea Level could have been 5-6 meters higher in the Bahamas during this period.
Influence of Bering Strait flow and North Atlantic circulation on glacial sea-level changes
PUBLISHED ONLINE: 10 JANUARY 2010 | DOI: 10.1038/NGEO729
Study: http://www.cgd.ucar.edu/ccr/publications/ngeo729.pdf
Figure 1: http://www.nature.com/ngeo/journal/v3/n2/fig_tab/ngeo729_F1.html

Ian H

Excellent. Thanks. We need more stories like this. It is good to see the idea that AGW is probably not C getting discussed.
In taking a skeptical view of CAGW there are lots of people who will jump up to immediately dispute the AGW part who never get to discussing the C. From my point of view C is the most interesting letter and the evidence for Catastrophe is the weakest part of the entire CAGW story.

JimF

Great post, William.
I fully concur with:
John F. Hultquist says:
December 30, 2010 at 1:14 pm
“…I’ll restate this as Earth is dynamic. Some of the research dollars being thrown at the AGW concept might better be applied toward a better understanding of the transitions described in the McClenney Antithesis….”
These data and interpretations are very disturbing. It appears that in these latter days the Earth is being jerked around something fierce, if the data actually are meaningful. If this: “…abrupt warmings {or to put it another way, and much more ominously, coolings} that occurred from just a few years to mere decades that average between 8-10C rises (D-O 19 scored 16C)…” were to begin to happen to us now, I would imagine that millions would perish and all hell would break loose.
We should be spending our taxpayer dollars – if at all – on science without an agenda – science to understand our planet. Maybe the AGW folks are right, and maybe they’re wrong, but the focus of tax-payer funded science should be knowledge, period. We should ask our politicians to review and alter the governmental funding of science (and I think the new Republican majority in the House would be disposed to see it thus). Meanwhile we should withdraw funding from political purposes such as the IPCC (and much of anything else the United Nations does).

Z

tallbloke says:
December 30, 2010 at 1:34 pm
[banzai voice]
It’s the great glaciation guesswork gamble! Will we freeze our fundaments off in:
a) 500 years?
b)1500 years?
c)50000 years?
Place bets NOW!!!

What I’m bothered about are:
a) 5 years
b) 15 years
c) 50 years
Everything else is someone else’s problem. Now if it did come to pass that we had an glacial period in our my lifetime, then I will be very upset.
I may even write a snotty letter to the Guardian.