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.”
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)
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.
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.”
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.
R. de Haan wrote on December 30, 2010 at 1:00 pm
QUOTE
You must be a great lover of fairy tails.
UNQUOTE
RdeH – I am such a bad speller and typist that I rarely get to correct other’s work.
I think you meant “fairy TALES” as in stories, not tails as in monkeys’ tails.
If you are not aware, then I will advise you.
As faries are part of the genus Homus MakeItUptus, fairies no longer have tails but are expert at spinning stories such as the tale of the bad demon CO2.
Could be another 2-4kyrs. We are most similar from an orbital perspective to the 420kyr interglacial (eccentricity and obliquity in phase).
http://s852.photobucket.com/albums/ab89/etregembo/?action=view¤t=GW_08202007_9174_image001.gif
I’d say we’ve been entering the glacial period for about 3500yrs…the green line is the average of GISP2 and Vostok…we may get another hump in the NH, but I don’t think it will reach the norm for the Holocene. Getting harder to stay at the upper rail for the NH.
http://s852.photobucket.com/albums/ab89/etregembo/?action=view¤t=GISP2_VOSTOK_INTERGLACIAL.jpg
Question is…will we get another 1168yr peak. 3 is very common, but not 4. If the sun is at 1959 levels for SC26/27 I’d say yes. If not, some definite cold coming our way IMO.
http://s852.photobucket.com/albums/ab89/etregembo/?action=view¤t=GISP2-Zoom.jpg
A big problem is not having GISP2 data (or equivalent) that goes back to 420kyrs. I have a feeling the phasing is critical, which hemisphere starts the interglacial first, etc…. It’s difficult to judge interglacial length with only a southern hemisphere proxy, as it is not a global proxy, only a SH proxy.
Judging by the comparison of the GISP2 and Vostok, the two hemispheres behave quite differently, looking at the 550oyr cycle which has a long term opposing trend for the two hemispheres. NH tried first (DO event), the SH ramped up and stayed up at 11150yrs (while the NH cooled back down), followed by the NH ramping and staying up at 9750yrs (with a slight cooling trend in the SH), whereby they both opposed eachother, especially so with the LIA (NH nulled, SH peaked) with the next opposing trend continuing today, albeit with a potential third long term hump for the NH (probably the last gasp IMO).
http://s852.photobucket.com/albums/ab89/etregembo/?action=view¤t=GISP2_VOSTOK_INTERGLACIAL.jpg
And yes, before you say it, I CAN read tea leaves too…
[URL already fixed. ~dbs, mod.]
“sophocles says:
December 30, 2010 at 7:06 pm
Professor Nir Shaviv’s (Jerusalem University) research could help answer some of the questions raised about ice age cycles. If Shaviv is right, the next ice age could start real soon now and be a humdinger … but before it does, we can expect a lot of ups and downs in warming/cooling.”
I believe we are already in the Ice Age (occurs roughly every 100 million years, which I believe Shaviv’s theory tries to address, please correct me if I’m wrong). Now the timescale is really the Glacial and Interglacial within the Ice Age we are currently in. And of course all of the high frequency noise we’re all hung up on with the climate debate in general.
I think in general ( as moronic as it sounds) that the Earth “prefers” the upper rail for temperature, hence the unequal rate for entering either the Interglacial or the Glacial period. You could guess CO2 though my hunch is Water in it’s various forms as the main culrpit (can you say Ocean?). During the non-ice age eras (previous to the last few million years, between this and the previous Ice Age), the Earth stayed at an upper rail. During the Interglacials of our current Ice Age Epoch, the Earth stays at the upper rails during the interglacials. It enters or tries to, the upper rails rather quickly, but descends into the glacial periods much more slowly (even with CO2 attempting to hold it up there, or Water, whatever your God). As for a runaway scenario…poppycock! We’d have been fried long ago with this upper rail preference. Much too consistent of an upper rail at least for the last 5 interglacials (with very different orbital phasings), and I’d guess outside of the Ice Age epochs, it’s pretty consistent as well. Otherwise, we little primates wouldn’t be sitting here contemplating this high frequency noise we call Climate.
You might like to explain what these people think they are doing then:
http://www.350.org/en/mission
Really, the Earth’s climate is mostly regulated by which phase the planet’s water is in. The physics are 100% different between glacials and interglacials. One reason that Hansen’s derivation of climate sensitivity during the LGM is silly and misguided. Think it through and you’ll see what I mean (hint: water vapor is a GHG and water on Earth is finite)
Ok, so, given all the physics that goes into the equations, it is obvious that the Earth in its current state is impossible. Negative feedbacks should nail Earth down into an Ice Age, and positive feedbacks should have all of us collecting condensation on the inside.
Since the Chixulub cometary/meteorite impact some 60 – 65 million years-before-present (YBP), six geological eras averaging a diffuse 12 – 16-million years have preceded our current Pleistocene Era of about 2.6-million years’ duration. Characterized by recurring glaciations averaging some 102,000 years, interspersed with median 12,250-year remissions of continental ice-sheets, cyclical Pleistocene temperature-patterns should persist another 12 – 14+ million years. Pending long-term plate tectonic shifts separating North and South American land-masses, restoring global atmospheric circulation between eastern and western hemispheres, recurrent Pleistocene glaciations will no doubt run true-to-form.
Geophysical evidence indicates that continental glaciers began retreating worldwide from c. 14,400 YBP, abruptly vanishing by c. 12,700 YBP (1,700 years). If not for a 1,500-year “cold shock” called the Younger Dryas, due to astronomical impacts rather than climatological factors, Earth’s present Holocene Interglacial Epoch would likely have ended about AD 450, coincident with termination of the so-called Roman Warm. As it stands, despite a diminishing rebound from a 500-year Little Ice Age lasting c. 1375 – 1875, since about AD 1950 the Holocene’s “long summer” has been fading fast.
In context and perspective, then, climate research conducted with integrity serves mainly to confirm the obvious: For whatever reasons, however humanity may wish otherwise, Ice Time looms again. As a decades-long “dead sun” phase diminishes Total Solar Irradiation (TSI) amid reinforcing Milankovich and other cycles, radical climatic shifts may well bring catastrophic cooling that reduces 80% of Earth’s arable land-area to frozen waste by 2100 if not well before.
A somewhat crude compilation of several images and data sets – but it does show a lot of the different contributors and their relationships
Two minor glitches in the post:
“Figure 2. Tzedakis (2010) comparing the Holocene with the previous 4 interglacials” is not appearing in the larger image format (tzedakis-2010-fig-31.jpg), and
“about 11873 ka ago” should read 118point73 ka (the “ago” is redundant).
Those minor typos do not detract from an otherwise excellent post. Thank you, Mr. McClenney.
Bill Illis says: Right now, the winter snow (except for high elevations) melts on Ellesmere Island and northern Greenland in the summer. The Arctic sea ice melts back at 75N in the summer. If the summer solar insolation is not going decline very much at this latitude for at least 50,000 years, the ice-Albedo-feedback will not kick in. The forecasts say it is not going to happen for probably 170,000 years. The summer sunshine will be warm enough to melt the winter snow and no additional glaciers will build up.
That hypothesis assumes that SSI-75N is the only driver (and/or trigger) of initial ice build-up and that some value less than 470 watts/m2 SSI-65N is the trigger point. But ice build-up has apparently been triggered at SSI values greater than that previously during the Pleistocene. Or am I wrong about that? Please explain.
Global warming was over with over 8,000 years ago and it has been a roller coaster ride down since. The only question is , is there an up after the down that we are starting on now. At some point the snow cover on the northern parts of the land masses forgets to melt completely and starts to build up. CO2 has nothing to do with it. pg
Z says:
December 30, 2010 at 3:08 pm
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
[Donald Sutherland voice]
Don’t give me the negative waves!
About that irony, yes it certainly would. In fact, let’s see what the Godfather of the AGW crime syndicate himself had to say about this VERY recently:
These fools would send us into an ice age without blinking an eye if we let them. Sure, some places are very safe like Hawaii, Florida, Mexico, Central America and Australia, but Europe, USA, Canada, lower South America and Asia have a bullseye painted on them. But the AGW cabal cares about neither, proven as we have recently witnessed escalating deaths from severe cold in Europe. Many more of those human sacrifices on the altar of AGW paganism can be expected.
So, taking these fools at their word that CO2 will cook the atmosphere, I vote for a large CO2 cushion to be in place ASAP (before the Day after Tomorrow ;-). I’m thinking 600 to 1000ppm (a little more than a doubling) is do-able. That should require us approximately 300 to 500 years time, during which we can hopefully develop and perfect a workable non-steam nuclear or fusion based replacement for electricity generation.
In the meantime we are using quite a few more incandescents than usual. This is completely out of necessity. Heat!
Hindsight & Foresight – Study the period from the apex of the MWP to the depth of the LIA to see the likely immediate future. (None of us will “see” much of this future happen, but it gives more insight than anything we can imagine today with or without all that beautiful O-C-O we’ve been creating.)
We are cooling, folks; for how long even kim doesn’t know.
================
Good post.
Unfortunately, with my level of knowledge concerning geology, it only succeeded in anesthetizing me. ;~P
“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. ”
And all man has done is to use the energy resources stored here by ages past.
How many W/m2 does man release each day?
Are we really prepared to accept an icy consequential outcome that may result if man interferes with the C02 content of Earth’s atmosphere? Climapolicy has already been unleashed in selected places with an iron fist, much to the distress of those downhill from the proclamtion.
“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. ”
Right on, Mr. McClenney!! Since modern, global man has risen to his current social and productive state in this current interglacial, it would seem wise to extend this period for as long as possible. The consequences of another iteration of the proven glaciation/interglaciation cycle being played to its end-game of sure destruction is incomprehensible. The horror of the Earths’s teeming masses crowded onto the remaining equatorial land masses as the ice sheet advances must be avoided at all cost.
The best solution to this problem is in the institution of a carbon reward system, the coating of all snow and ice covered parts of the planet with powdered carbon, the change of all existing rooftops to black materials, wholesale interference with all of Earth’s known cooling mechanisms. Primary among those interferences should be to build enough windmills to harness up to 25% of the available wind energy and to develop a technology that would harness a significant amount of the ocean current energy. We may even have time to wrap the Moon in wire and create a large induction system and use the resultant energy to power directional heating elements to warm the Earth.
These initiatives must be accomplished post-haste and will require hundreds of trillions of dollars. No time to think…must act…oh, the humanity…mumble…mumble…
Brian H says:
December 30, 2010 at 7:27 pm
alan says:
December 30, 2010 at 6:27 pm
Spot the risible oxymoron in your post! 😉
alan says:
Yes! Also consider this: Terraform = bringing “terror” to the Red Planet. Perhaps they can hijack a rocket that will get them there. It probably won’t be a NASA vehicle though!
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.
Yeah, “we” sceptics are left to actually think. Because on the other hand, ipcc CO2CAGW “Climate Science” has only selected the precaution to not ask itself what’s wrong with what it is saying, proposing, or doing……obviously because it might find out that it is wrong, which sounds pretty reasonable to the Climate Scientists.
And – just coincidentally, I’m sure – being wrong is also a possibility that no respectable Propaganda Op. should ever allow! Of course, if you are one of Kealey’s “great scientists” there is no reason or urge to ask yourself anything about what you think, because you automatically never “feel falsified” to begin with.
—————-
Pascvaks,
Yes, I completely agree with you. There is very little need for concern about any imminent catastrophic/end-of-the-world style doom and gloom regarding the descent of this interglacial into the next glacial. The past descent from interglacial to glacial, based on papers, show a very slow gradual decline spanning hundreds/thousands of years in transition.
A Happy New Year to you.
John
Hansen: “Therefore, it is foolish to demand that policy makers reduce CO2 to 280 ppm. Indeed, if, with a magic wand, we reduced CO2 from today’s 389 ppm to 280 ppm that change would increase Earth’s heat radiation to space by almost 2 watts (per square meter). The planet would rapidly move toward a colder climate, probably colder than the Little Ice Age.”
Does Hansen realize that he’s saying that fossil fuel CO2 which, according to him, is supposed to produce “the destruction of creation”, has already prevented a LIA?
By this time the Muslim nations must already be dancing in the street, probably even without the Obama Adm.’s transformative prime directive to NASA that its main mission is to help the Muslim nations increase their self-esteem – even though the President seems to think that their “historic” achievements in the areas of math, science, and engineering are still only historic – apparently by making U.S. science look really stupid. But I guess it probably does help to make Hansen’s valiant efforts in this regard “official”.
Sal Minella says: (December 31, 2010 at 9:48 am)
You make me sick.
Slight correction. Chamberlin (1890) described the method of multiple working hypotheses, not the theory of multiple working hypotheses.
Chamberlin, T.C., 1890, The method of multiple
working hypotheses: Science (old series) v.
15, p. 92-96; reprinted 1965, v. 148, p. 754-759.
http://www.geology.und.edu/gerla/gge487_488_494/chamberlin1890science.pdf
Fascinating. The implication of Fig3 is quite interesting. Some theories say that the Arctic ocean “needs” to become ice-free for most of the yr (that would imply Greenland might melt significantly, too) to produce the necessary snow-amounts to last thru summer, to end an interglacial period. At present, there isn’t enough precipitation up there (~5 inches liquid/yr) to make enough snow.