Guest post by William F. McClenney
This post is essentially an update to The Antithesis and On “Trap Speed”, the ACC and the SNR.
The entire non-debate on anthropogenic climate effects has always struck me “as two fleas arguing over who owns the dog they are riding on” (Crocodile Dundee). One of the required paradigms of AGW is patently ignoring “when we live” (ignorance of signal to noise ratio, or SNR).
We live today possibly near the end of the most recent interglacial, the Holocene, or the 11,715 years since we melted our way out of the last glacial, the Wisconsin Ice Age, the interglacial in which all of human civilization has occurred. Five of the last six interglacials have each lasted about half a precession cycle. The precession cycle itself varies between 19,000 and 23,000 years and we are close to the 23kyr point now, making 11,715 years about half……..which is why this discussion has relevance.
So when will the Holocene end?
Even if you are not presently afraid of
But first a look at the often painful, difficult advance of Science.
Who was Alfred Lohar Wegener?
“He was the object of a kind of loathing that is only rarely seen in science.
“It wasn’t long before the established authorities closed ranks against Wegener’s concept as if they were stamping out a plague. He never understood the depth of resistance to his thinking. Continental drift was received not merely as a mistaken idea but as an evil that jeopardized the credibility of geology as a science and the professional reputation of anyone who espoused it. Wegener was denied professorships at German universities, but eventually he found himself at the University of Graz in Austria. Ironically, though, in 1928, he was asked to lead a German expedition to Greenland.”
–John D. Cox, “Climate Crash: Abrupt Climate Change and What it Means for Our Future”, ISBN: 0-309-54565-X, Joseph Henry Press (an imprint of the National Academies Press), 2005
The expedition got underway in 1930. In November,1930, Ernst Sorge, of Wegener’s Greenland meteorological expedition, discovered for the first time the records of paleoclimate preserved in the ice.
“It would be some years before researchers would fully appreciate the value of Ernst Sorge’s cold and lonely work in the winter of 1930 when he sawed and chipped and shoveled a shaft 54 feet down into the Greenland ice. Glaciologists at the time thought of the ice sheets almost exclusively as geological features whose movement across the landscape chronicled the slow waltz of a changing climate.”
Wegener died that winter of 1930. His Continental Drift theory of 1912 would not be proven until the 1960’s, revolutionizing geology as the Theory of Plate Tectonics. It would be 30 years beyond that (the 1990s) before the scientific contributions of Ernst Sorge were fully recognized as another revolutionary concept: Abrupt Climate Change.
When Do We Live?
Concern about abrupt climate change is especially inversely healthy today, as the Holocene is but the latest of the post Mid Pleistocene Transition (MPT) Extreme Interglacials, a thing almost nobody knows. An Extreme Interglacial can be variously described as a technical aspect of Ice Rafted Debris (IRD) in the ocean stratigraphic record, or more frequently as an interglacial that has achieved at least our sea level or our isotopic temps (<3.6 o/oo dO18). There is also a bit of controversy as to just which of the post MPT interglacials qualify. For the purposes of this essay we will define them as Marine Isotope Stages (MIS) 11, 5e (the Eemian) and 1 (the Holocene), with provisional inclusion of MIS-19, for reasons we will delve into.
Figure 1 Post-MPT interglacials with an expansion of part of the last glacial period and the Holocene. (Note: MIS-19 is unlabeled at the far left – click to enlarge)
As one may glean from Figure 1, something seems to have happened to the 100kyr amplitude about 400kyrs ago, the climate ride got a tad wilder from then to present. The speculation is long and worth researching yourself, however it is not exactly the subject of this piece.
As discussed in The Antithesis, we could very well be at the end of the most recent extreme interglacial. Although it is quite likely this thought will strike many as trivial, for some inexplicable reason it seems reasonable to wonder what the ends of the other extreme interglacials might have been like.
If AGW/CAGW causes you qualms, queasiness or abject terror/irrational rage, then you would be wise to take the exit ramp here.
Because there is, and has been, a long-running debate in the paleoclimatology literature that I suspect few of you have ever heard of, and it kicked off at the same time as the AGW hypothesis (or theory for post-normal scientists).
Wallace Broecker, arguably one of the fathers of modern paleoclimatology provides the best of the earliest quotes as regards this debate:
The next year (1999), in a paper posted on the Cambridge Conference Network (CCNet) by famous astronomer Fred Hoyle (originator of the now disfavored Steady State Theory Hypothesis), it was stated:
“This is why the past million years has been essentially a continuing ice-age, broken occasionally by short-lived interglacials. It is also why those who have engaged in lurid talk over an enhanced greenhouse effect raising the Earth’s temperature by a degree or two should be seen as both demented and dangerous. The problem for the present swollen human species is of a drift back into an ice-age, not away from an ice-age.”
Bringing it up to the present, we have this:
Public release date: 8-Jan-2012
Contact: Jim Channell
352-392-3658
University of Florida
Global warming caused by greenhouse gases delays natural patterns of glaciation, researchers say
GAINESVILLE, Fla. — published online Jan. 8 in Nature Geoscience.
“The Earth’s current warm period that began about 11,000 years ago should give way to another ice age within about 1,500 years, according to accepted astronomical models. However, current levels of carbon dioxide are trapping too much heat in the atmosphere to allow the Earth to cool as it has in its prehistoric past in response to changes in Earth’s orbital pattern.”
Which is more or less where Broecker was coming from in 1998 and where we ended up in “The Antithesis”. A hypothesis that we might extend the present interglacial by the timely venting of a “climate security blanket”, if you will. Also known as the Industrial Age.
Just to recap a bit of that, Loutre and Berger (Loutre M. F. and Berger A.: Marine Isotope Stage 11 as an analogue for the present interglacial, Global Planet Change, 36, 209–217, 2003) predicted, from a computer model, 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 (some say over the last 5MY).
Of course, this was a model, for those enamored with models. It was soon put to rest by Lisiecki and Raymo (A Pliocene-Pleistocene stack of 57 globally distributed benthic D18O records, Paleoceanography, Vol. 20, PA1003, doi:10.1029/2004PA001071, 2005) which was quoted in “The Antithesis”, and will be again later in this discussion.
So this does indeed bear some serious scrutiny. We will begin with the Cenozoic and work our way to better and better resolutions. I again apologize for the presentation of some of these graphics. I whipped some of them together from professional papers for a slide show some years back, but, unfortunately, failed to take the time to properly reference them.
Figure 2. The Cenozoic
There are a great many things to be pondered in Figure 2. Why have we been roughly cooling off since the PETM? Is the increase in climate variability about the mean since the dinosaurs to present indicative of (a) poorer proxies or less data with time? or (b) truly indicative of a gradually more variable climate? Would comparisons of climate at the PETM be valid for a post Panama Seaway closed world? And those are just a few.
Figure 3. Expanding out the last 5 million years of climate (the LR04 Age Model)
In Figure 3 we expand out the past 5 million years of climate change developed from those 57 deep ocean drilling program cores of Lisiecki and Raymo (2005). We see the beginning of the 41kyr obliquity paced million years of glacial/interglacial oscillation about 2.8mya and we see the initiation of the eccentricity paced 100kyr pairings at about 0.8-1mya. We see again the onset of the extreme interglaciations at about 400kyrs.
Figure 4. Expanding out post MPT time. (Note the different time scales on the lower merged image at about 140kyrs)
In Figure 4, we zoom-in yet more on the post-MPT time beginning with MIS-19. In this depiction we see that MIS-19 did not appear to achieve temperatures of the true extreme interglacials, but it does have a lot more to offer. Orbitaly, it could be our closest interglacial analog in the climate record, although this is a matter of some debate in the literature.
The End Extreme Interglacials
MIS-19
Which brings us to the point of this essay, what were the end extreme interglacials like? Although MIS-19 may not satisfy everyone as being an extreme interglacial, it did occur at an eccentricity minimum just like MIS-11 was and MIS-1 presently is. So in terms of trying to comprehend what might be the end extreme interglacial natural climate noise it has “standing”.
Figure 5. Multi-proxy view of post-MPT time.
So what was the end of MIS-19 like?
Figure 6. Three Consecutive Warm Events at Glacial Inception During MIS-19
Well, MIS-19 appears to have had at least 3 abrupt warming events during glacial inception. Had the genus Homo gone all-civilized on us during MIS-19, we would all have had one heck of a time settling our AGW damage claims with our climate-change insurers, especially with the final one being of the highest dD amplitude. If any insurance types are here, I just gave you the proverbial “silver bullet” for rejecting AGW related climate damage claims. So collect your premiums with the appropriate conceit of a proper Wall Streeter, unless, of course, you also issue coverage for natural climate changes or “Acts of God”.
K. Pol et al. (2010) also attempt various astronomic and MIS-1 fittings to see how ours “stacks up” (Figure 6). Could we also be in range of such events?
MIS-11
Which brings us to MIS-11, the Holsteinian interglacial. Remember I said that 5 of the last 6 interglacials all lasted about half of a precessional cycle? Well that 6th one was MIS-11.
Figure 7. New MIS-11 as Corrected for Isotopic Fractionation (K.Pol et al, 2011)
MIS-11 has long been shown to consist of at least two insolation peaks, a fairly sharp one soon after glacial termination, and a long, fairly broad one after an interval of cooling. But if you take the time to closely inspect all of the figures presented here, you will likely note that they are not all the same everywhere and in every study. It’s called science. The estimated length of MIS-11 seems to vary from 20-33kyrs, depending upon which study you are reading.
At the risk of repetition from “The Antithesis”, Lisiecki and Raymo (2005) state:
“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 effectivelyprecludes a ‘double precession-cycle’ interglacial [e.g., Raymo, 1997] in the Holocene without human influence.”
Chronis Tzedakis, in an exhaustive look at the MIS-1/MIS-11/MIS-19 conundrum (Tzedakis, 2010, The MIS 11 – MIS 1 analogy, southern European vegetation, atmospheric methane and the “early anthropogenic hypothesis”, Climate of the Past, vol. 6, pp 131-144, European Geosciences Union) considers the matter thusly:
“While the astronomical analogy between MIS 1 and MIS11 has been incorporated in mainstream literature, there is a distinct difference between the two intervals: the Holocene contains one insolation peak so far, while the MIS 11 interval of full interglacial conditions (Substage 11c of the marine isotopic stratigraphy) extends over two insolation peaks. Thus an interesting situation has arisen with regard to the precise alignment of the two intervals.”
“The two schemes lead to very different conclusions about the length of the current interglacial, in the absence of anthropogenic forcing, …
“… the precessional alignment would suggest that the Holocene is nearing its end, “while the obliquity alignment would suggest it has another 12,000 years to run its course.
“In this view, the two Terminations are incommensurate and MIS-1 is analogous only to the second part of MIS-11c.”
Figure 8. Tzedakis’ 2010 Alignments of the EDC3 core for the Holocene and MIS-11
Figure 9. Another recent view of the Twin-Peak Nature of MIS-11
Figure 10. MIS-11 from Lake Baikal sediments.
Multiple views of MIS-11 clearly indicate a Twin-Peak configuration, though, as one might well expect, varies from one place to the next. K, Pol et al (2011) and Tzedakis (2010) both tend to show an elongated and higher amplitude late peak for MIS-11a whereas Voelker et al (2009) and Prokopenko et al (Clim. Past, 6, 31–48, 2010, www.clim-past.net/6/31/2010/) show a broader, more symmetrical pair of peaks.
Apparently, the second one was a real doosie:
As we leave the double insolation-peak MIS-11, with it’s possible +21.3m amsl highstand and 20-33kyr length, I am again struck by the magnitude of both the natural noise and the difficulty one will have winning an argument with a clued-in climate change insurer over a whopping IPCC AR4 worst case +0.59m amsl fizzle, with or without it’s consensus accolades.
MIS-5e
Which brings us to the most recent interglacial, the Eemian, or MIS-5e. As it occurred midway between the last eccentricity maximum and our present minimum it is not considered to be a good orbital analog. However it seems to have also been quite the extreme little interglacial.
I will again be using some citations quoted in “The Antithesis” to “insure” against the risk that some of the “insured” won’t get it.
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 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. 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.”
Savvy insurers take note to make appropriate use of the “Acts of God” clauses.
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.”
Figure 11. Hearty et al (2007) End Eemian highstand(s)
Figure 12. Hearty et al (2007) modern MIS-1 notch and MIS-5e notches in the Bahamas and Barbados
Figure 13. MIS-5e Sea Levels Compiled from Around the World (modified after Hearty et al, 2007, red estimates added)
In Figures 10-13, we see the End Eemian in quite remarkable detail. This is predominantly due to its relatively young age compared to any other interglacial. One needs but to consider the effects of the average 400 foot sea level swings in and out of each of them, some going higher than others, to grasp how each of them tend to erase the evidence from the others. For instance, paleoclimatologists that are adept at deep sea diving might be able to uncover evidences of say MIS-7 and MIS-9 sea level highstands because they are presently below sea level. I wouldn’t take out to much insurance on that though.
And look at the range of estimates, +6m to +45m amsl, and often detecting the highstands at the very end of the Eemian.
In discussing the Late Eemian Aridity Pulse (LEAP) at the end-Eemian, Sirocko et al (A late Eemian aridity pulse in central Europe during the last glacial inception, nature, vol. 436, 11 August 2005, doi:10.1038/nature03905, pp 833-836) opine:
“Investigating the processes that led to the end of the last interglacial period is relevant for understanding how our ongoing interglacial will end, which has been a matter of much debate…..”
“The onset of the LEAP occurred within less than two decades, demonstrating the existence of a sharp threshold, which must be near 416 Wm2, which is the 65oN July insolation for 118 kyr BP (ref. 9). This value is only slightly below today’s value of 428 Wm2. Insolation will remain at this level slightly above the inception for the next 4,000 years before it then increases again.”
Now that is some bombshell! We may only have about the next 4,000 years, a little less than half the time since we “Homos” learned how to write, where climate sensitivity will be alarmingly close to glacial inception.
“The Antithesis” provides documentation of CO2 effects during the latter half of the last glacial, so I will refer you to that essay for the succulent details. Suffice it to say that what this may boil down to is strip the appropriate amount of “climate security blanket” out of the late Holocene atmosphere as fast as is humanly possible (perhaps tipping us into the next ice age), or keep a decently healthy dose of it up there for at least the next 4,000 years.
So there you have it, all tipping points now in play.
THE END HOLOCENE
So we now have quite the conundrum. Will we do a typical eccentricity minima sea-level “Cha-Cha” at our very end? It would appear to be the norm, and may not be restricted just to eccentricity minima end extreme interglacials given the “competition” from MIS-5e, which occurred neither at an eccentricity minima or maxima.
And they do appear to be rather extreme, don’t they? So do not be too shy about investing in savvy climate change policy writing insurers. If they read this, they will probably never have to pay out a claim. Pay attention Big Oil etc., you could have a field day on Kivalina and other Public Trust Doctrine style litigation just by “stocking-up” on what has “gone down” climate-wise, without even having to be exposed to the heathen devil gas itself.
From I what I have been able to glean, this seems to boil down to three competing hypotheses:
- Anthropogenic Global Warming/Catastrophic AGW. World will continue to warm, perhaps catastrophically, as a result of GHG emissions.
IPCC AR4 worst case estimate for sea level by 2100 is +0.59 meters amsl. End Eemian achieved, at least, 10 times this (if we use +6 meters amsl), almost an order of magnitude more if we use the +45m estimate. End Holsteinian achieved 36 times this predicted excursion (using 21.3 meters amsl), covering the low and high ends of natural, end extreme interglacial, climate noise.
The Signal to Noise Ratio (SNR) range for AGW predictions to 2100 come in at a range of 0.1 to 0.03 compared to “normal” end extreme interglacial climate noise. Worst case projections are therefore woefully not anomalous (at best 10% of natural noise), with the projected AGW/CAGW signal scoring a measly 3-10% of normal end extreme interglacial climate noise levels.
Such a signal will be difficult to distinguish.
- Holocene Interglacial (Loutre and Berger, 2003) will “go-long” (perhaps another 50,000 years), outlasting every previous interglacial in the past 5 million years.
“With the end of MIS 11 full interglacial conditions and the start of ice accumulation estimated to have occurred at 395 kyr BP (de Abreu et al., 2005; Ruddiman 2005a, 2007), the precessional alignment would suggest that the Holocene is nearing its end, while the obliquity alignment would suggest it has another 12 000 years to run its course.” (Tzedakis, 2010)
“In essence, this alignment represents a synchronization of the obliquity signal instead of precession, which according to Masson-Delmotte et al. (2006) may be more appropriate, because of the role of obliquity changes in triggering deglaciation especially during intervals of weak precessional variations, as is the case for MIS 11 and 1.” (Tzedakis, 2010)
- Holocene is a tad over half-a precession cycle old now. If a precession match, it might be “winding-up” to “wind-down”, like all previous end extreme interglacials.
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.
We may have actually already “engineered” a “climate security blanket” capable of dealing with:
“The onset of the LEAP occurred within less than two decades, demonstrating the existence of a sharp threshold, which must be near 416 Wm2, which is the 65oN July insolation for 118 kyr BP (ref. 9). This value is only slightly below today’s value of 428 Wm2. Insolation will remain at this level slightly above the glacial inception for the next 4,000 years before it then increases again.”
Apologies for quoting Sirocko et al (2005) twice in rapid succession.
Which rather handily devolves to,
Have a wonderful end extreme interglacial!
William F. McClenney
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This is simply more baffle-gab from the true believers and has nothing to do with geological sciences what so ever.
There is no evidence that marginal changes in CO2 has enough of a warming effect to make a difference. Yes, it has SOME warming effect, but little effects don’t cut it. This is the lesson of abrupt change. The most likely candidate (a near certainty) is albedo feedbacks. As snow and ice build up, they reflect away more sun, cooling the planet and inducing more snow and ice.
Starting from a warm period, with relatively little snow and ice, this cooling feedback rapidly increases in strength as snow and ice descend to lower latitudes. That’s because the land area covered by one degree of latitude rapidly increases as latitudes decrease. The angle of insolation is similarly getting steeper, so the amount sunlight reflected away by snow and ice ramps up by both of these factors.
Take away the IPCC misattribution of solar magnetic warming effects to CO2 and the puny warming effect of CO2 that is left is NOTHING compared to these massive albedo feedbacks. The only way CO2 could stop glaciaton is if it were in a position to make just enough difference at some key inflection point. For instance, the little ice age that will result if the sun stays quiet for a couple of solar cycles would have to bring temperatures down to just the tipping point to the next glaciation. Then CO2 could make a difference.
But we are much more likely to go roaring into the next glaciation, in which case the tiny effect of CO2 will be completely overwhelmed by the much larger albedo feedback effects. What are the chances that the sun will rebound just in time to stop albedo feedbacks from running away? The chance that a tiny marginal effect is going to make the difference is tiny.
What we need to be prepared to do is to interrupt the albedo feedback effects. My thought has long been to dot the great white north with coal-electric generating plants that burn clean in the summer in the old fashioned sense of not producing soot, but still producing CO2, then run them dirty in the winter in the old fashioned sense of producing lots and lots of snow-darkening soot.
But generating plants would probably not the best way to darken the snow. It just sounds good because it is a two-fer, but building the transmission lines necessary to make use of the electricity would almost certainly not be economically viable, so the efficient thing would just be to design the most efficient soot-producing plants possible and have them produce just enough electricity to operate and provide for support operations. Maybe the plants would be built near coal deposits where they could support mini-mining operations to pull out the fuel.
We should be building such plants NOW, just in case the present solar minimum does spawn alarming albedo feedbacks that we suddenly realize we need to try to interrupt. If the capacity is not already in place, it will be too late.
Dennis Nikols, P. Geo says:
March 16, 2012 at 9:29 am
This is simply more baffle-gab from the true believers and has nothing to do with geological sciences what so ever.
Dennis: One P.Geo. to another, please be more specific about who or what you are addressing.
Alec Rawls says:
March 16, 2012 at 9:49 am
There is no evidence that marginal changes in CO2 has enough of a warming effect to make a difference.
Well, there is some evidence, but in my opinion, not all that much:
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. ”
The rest I tend to mostly agree. I find your subarctic power plants a fascinating bit of geo-engineering if either/both CO2 and soot phenomena prove out to be insurance against the next glacial, whenever it finally gets here.
Ken Harvey says:
March 16, 2012 at 5:58 am
We are at the mercy of the Milky Way, but no doubt they will find a tax to fix it.
—————————
Ken, I bet they can.
Anthony
Is there any chance you can offer this as a pdf?
REPLY: Sure, look for an update to the main post soon – A
William McClenny quotes:
Makes sense. CO2’s power to mitigate cooling gets stronger as cooling progresses. This is because cooling dries out the atmosphere, making CO2’s IR absorption less redundant with water vapor. If albedo feedback effects were already exerting enough cooling force to overcome the heat trapping of both CO2 and the water vapor of a warm atmosphere it will certainly continue to overcome the heat trapping of CO2 alone, so the descent into glaciation will continue, but it won’t be as fast as if the ever-more effective heat-trapping of the CO2 were not there.
Eventually the CO2 will re-absorb into the cooler oceans, with their greater CO2 holding capacity.
Alec Rawls says:
http://wattsupwiththat.com/2012/03/16/the-end-holocene-or-how-to-make-out-like-a-madoff-climate-change-insurer/#comment-925282
Henry @Alec
Good post. I agree with most of it, but personally I am not (yet) sure if the net effect of more CO2 is that of (a tiny little bit) more warming or cooling. I have not seen anyone produce an actual balance sheet. Remember that the available graphs that we have on the sun’s and earth’s irradiance are rather crude and inconclusive (if I eyeball them). The actual absorptions (that overlap) of water vapor and oxygen/ozone at 14-16 um could be much higher then that indicated to be caused by the CO2.
If you are interested in looking into that a bit more, see CO2 re-radiation 101:
http://www.letterdash.com/HenryP/the-greenhouse-effect-and-the-principle-of-re-radiation-11-Aug-2011
As far as the next ice age is concerned – and even a little ice age could be devastating – I agree that we do not need some kind of action plan if snow and ice cover becomes so big that it could cause earth to tip back to its “natural” state of ice and snow. I suppose there might be other ways to stop the increasing albedo and melt the snow other than to throw soot on it?
In my last post, last sentence, should be:
I agree that we DO need some kind of action plan if snow and ice cover becomes so big that it could cause earth to tip back to its “natural” state of ice and snow. I suppose there might be other ways to stop the increasing albedo and melt the snow other than to throw soot on it?
William F. McClenney, great post, really great. This will require multiple reads.
I have been trying to put this overall Holocene climate big picture into words but you did it way better. A few weeks ago I wrote:
Where are we? That really is the biggest question of all. There is another important graph at Wikipedia Post Glacial Sea-Level Rise. Question: Is it not likely that the only real indicator that humans will detect of the turnaround from Holocene warming to re-glaciation will be when sea-level becomes flat and decreases? What other possible signals could someone envision?
About Milankovic … I think that his ‘theory’ must be placed in perspective. IMHO, it is more important to appreciate his quality of work rather than the final details of the theory because it would be absolutely stunning if he could have nailed it down 100% in his lifetime. He was practically a POW during WWI when he fleshed out all these orbital variables and insolation – quite an accomplishment and all without a computer and Internet access. He helped shift the focus from pseudo-science to real hard-science and mathematics with respect to the climate of the Earth and the Sun. Truly he was a pure Scientist, something that appears to be in very short supply these days. (Curiously, there is a fortuitous tie-in at the Milankovic Wikpedia entry to Wegener: “The results set forth in his [Milankovic’s] work won him a considerable reputation in the scientific world, notably for his “curve of insolation at the Earth’s surface”. This solar curve was not really accepted until 1924, when the great meteorologist and climatologist Wladimir Köppen, with his son-in-law Alfred Wegener, introduced the curve in their work entitled Climates of the geological past.”)
Finally, speaking of bucking the trend, later in the 20th century two more great Scientists, a father-son team had to swim against strong prevailing currents to advance our understanding of the K/T boundary and dinosaur extinction. I remember Luis and Walter Alvarez ideas’ being scoffed at practically as science fiction in the beginning on early Usenet discussion threads.
Anyway, in my opinion all of them, Milankovic, Wegener and the Alvarez team courageously dragged Science out of the dusty ivory towers and into the modern real world. And now the great pretenders like Jones, Mann, Hansen and Trenberth are trying to drag it right back to alarmism. It is our duty to stop them.
Very interesting article. I think this may also have an effect.
And I’ve noticed comments like this more often lately:
Global warming caused by greenhouse gases delays natural patterns of glaciation, researchers say
GAINESVILLE, Fla. — published online Jan. 8 in Nature Geoscience.
“…current levels of carbon dioxide are trapping too much heat in the atmosphere to allow the Earth to cool as it has in its prehistoric past in response to changes in Earth’s orbital pattern.”
So what they’re claiming is that the ≈40% rise in CO2 is just enough to balance the planet’s temperature to within 0.8K over the past century and a half. In other words, human emissions are calibrated to keep global temperatures on an even keel.
That is preposterous. If true, it means we know exactly how much CO2 to emit to keep temperatures from changing. Conclusion: don’t worry about the end of the Holocene, we can just tweak the climate.
As if.
Smokey says:
March 16, 2012 at 11:18 am
“That is preposterous. If true, it means we know exactly how much CO2 to emit to keep temperatures from changing.”
I am not sure what you are trying to convey here. So a shot in the dark. From what I have been able ferret out this is not about “exactly”, it’s about the general direction things might head and under what conditions we might find ourselves in. All informed speculation, at this point in our relative comprehension of the relevant sciences, tends to suggest that no one hypothesis gets the nomination because the results are not yet in from all precincts. Even if they were, somebody is bound to petition for a recount since vote counting is not exactly an exact science.
Strike, ball, first base or out?
William,
I wasn’t being critical of anything you wrote, I was commenting on one of the common alarmist talking points: that human CO2 emissions are keeping the next glaciation at bay. They specifically claimed that current levels of CO2 are preventing the earth from cooling. Since there has been no global warming for about 15 years now, their explanation is that CO2 emissions are exactly the right amount to cause neither global warming nor global cooling. Really, that’s how ridiculous their arguments have become.
Smokey says:
March 16, 2012 at 11:57 am
No worries, I actually took this route first, then backspaced it out and went the wrong direction, My bad not yours Smokey!
The complex science of global climate change has always been secondary to a few simply stated facts of what will directly impact humanity.
a) Moderate warming very good (MWP)
b) Allot of warming (3 deg. C), (may be bad, may be OK, we really don’t know)
c) A little cooling, very bad (LIA)
e) Allot of cooling, a global disaster (ice age)
Note: man made CO2 has very little or nothing to do with all of the above.
Thanks for this great post ! Ice ages are a fascinating conundrum.
The main effect of changes in eccentricity is to modulate the effect of the precession terms at 23,000 years. Indeed if the orbit was circular then the precession of the equinoxes would have no effect whatsoever. However the direct effect on insolation of the increase in ellipticity of the Earth’s orbit averaged over a year is negligible. This is the paradox as to why regular glaciations and warm interglacials occur every 100,000 years in phase with the eccentricity.
The clearest insolation effect on climate is the obliqueness signal which when averaged out over the combined ellipticity and precession yields a regular variation of around 25 watts/m2 in maximum flux. The delta 18O data show a clear signal throughout the 5 million year period in phase with obliquity. The precession signal is directly dependent on eccentricity and is less evident in the data. However there is no explanation for the primary 100,000 year variation in phase with ellipticity. An excellent review of this problem has been given by Maya Elkibbin & JoseA. Rial [Earth-Science Reviews 56 Ž2001. 161–177
] which highlights the questions that any complete theory of the evolution of Ice Ages must answer namely:
1. The observed gradual decrease in temperatures starting just over 3 million years ago.
2. The 43,000 year continuous signal dominated until about 1 million years ago when the onset of 70-100,00000 glacial cycles begin. Why did this happen ?
3. What is the cause of the recent 100,000y glacial cycles, since Insolation changes caused by ellipticity are too small to be an explanation ?
4. Why did the frequency change from about 70,000 years between 900-700,000 ybp to the current cycle of 100,000 years ?
5. Why is the larger 400,000 year eccentricity signal absent from recent data ?
Muller et al. have proposed an alternative explanation for the 100,000y cycle. They suggested that the driver is the change in inclination of the Earth’s orbit. This follows an 80,000 year cycle relative to the current ecliptic plane, but when projected to the invariate plane defined as the centre of mass plane of the solar system this is extended to 100,000 years. The physical process envisaged is that the interplanetary dust cloud is centerd on the invariate plane and the Earth passes through this during its orbit. Evidence from ocean sediments show a 100,000 year cycle of H3 deposits associated with cosmic dust [3]. In effect, changes to orbital parameters of eccentricity, inclination and longitude of ascending node are all caused by the mutual gravitation of solar system planets as they orbit the Sun. Similarly all bodies in the solar system will follow such cycles including dust clouds.
The hypothesis that the Earth passes through a static interplanetary dust cloud aligned with the invariate plane attenuating sunlight is attractive. Furthermore there is direct evidence in ocean sediments of a regular 100,000 cycle of He3 deposits [4]. Unfortunately the data do not seem to support inclination as being responsible, despite the similarity in timespans. One would expect colder temperatures at low alignment where presumably the Earth crosses the dust plane. The correlation with eccentricity is better with high eccentricity seemingly algning with warmer interglacial periods. So what is really happening and can we explain how the climate changed to regular glaciations ?
I investigated the possibility that the local IPD cloud was resonant with the Earth’s orbit and increased the density between Earth and Sun sychronised with changes in eccentricity. This would then accentuate slightly incident solar radiation with a 100 y cycle. However one would expect a signal for gthis in the TSR(solar constant) measurements, and none is apparent. So the full details of Ice ages are still a mystery (at least to me !)
AGW
A doubling of CO2 levels in the atmosphere by the end of this century will cause a direct radiative forcing of 5.3Ln(2) watts/m2 or 3.67 watts/m2. IPCC models usually assume a further feedback mainly from water vapor of 2 watts/m2/degC. A reasonable assumption would be that AGW would induce a warming term of about 5-6 watts/m2 after which CO2 levels are expected to stabilize. The net effect of all human induced global warming could be to increase radiative forcing by something like between 4 and 8 watts/m2.
The eccentricity of the Earth’s orbit is currently decreasing with cooling likely beginning in 2000 years time leading eventually to another intense Ice age after 20,000 years and lasting a further 60,000 years. A new Ice Age would be disastrous for human and animal life at large latitudes. To fully offset another Ice Age, I estimate it would be necessary to keep CO2 levels above about 700 ppm for another 70,000 years !
Gotta run folks. Dr.s’ appointment. Later……..
William McClenney, thank you so much for this article.
Now incorporate this article with the recent run on Farmland in Africa…. (Google African landgrab)
Hi William.
One thing that always bothers me when we see historical sea-levels relative to land – indeed you cite “Hearty et al (2007) End Eemian highstand(s)” with anything from +6 to +45 amsl.
However, to what extent do we know that the relative land-mass is stable vertically?
i.e. has sea-level truly gone down 45m, or has the land risen – or a combination of the two?
Excellent article. Thanks both, and another one here who will keep a look out for the pdf. (Which hasn’t stopped me running the page through CutePDF to read meanwhile!)
By my calculation it’s about a 2.8% drop in insolation between the non-glacial and glacial states.
So we’re betting it all on the notion that solar output can’t drop over that in this Sleepy Sun period.
Well, that sure makes me feel better /sarcoff;>
AndiC:
Again, it is a lot more complicated than you might think. The Bahamas (hope my fever-adled brain picked the right set of islands, but it might be the Caymans…) look to be on a stable platform of oceanic plate sliding sideways some distance from the mid-Atlantic Ridge. But stable platform conditions where evidence of highstands has been found are rather rare. From there it becomes necessary for the workers to attempt to work out what they think rates of change for each locale where evidence has been found. Under the hairy eyeball, this can seem a lot like adjusting data to fit ones preconceptions, regardless of how well justified. Meaning a varying depth of assumptions blurring the line with modeling.
So, as with anything scientific, the level of due diligence you practice will determine your degree of vision and understanding. Assuming you are not wearing polarizing shades. Where tectonism is active, one is more or less compelled to understand the minutiae of how the authors arrived at whatever their conclusions are, and how you weigh all of that objectively. For instance, a lot of very riveting work has been done in the Mediterranean, several Italian studies come to mind, some speleothem (stalagmite/stalagtite), some sedimentary and geomorphic etc. Your success at perceiving all of this is more or less a factor of how much such reading, studying and comparative thought you can apply. This tends to grow in concert with exposure to the literature, your comprehension of it, and just how many stones you decide to leave unturned……
If you are unfamiliar with this, find the Hearty et al 2007 paper:
http://www.uow.edu.au/sbs/content/groups/public/@web/@sci/@eesc/documents/doc/uow045009.pdf
Proceed to their Figure 2 (page 2092), then check each reference cited therein in the References section, run each of them down, be prepared to shell out some bucks for the paywalled ones, knowing full well that thorough due diligence often incurs expenditures to turn over more and more stones (to leave no stone unturned, etc.). In order to vet some of the incorporated science, such as jumping headfirst into the state-of-the-art firn understanding, for example, you might have to wander along myriad tangents. And it gets harder and harder to stooge you.
Get good at it and the intensity of litigation support can be addictive…….
E.M.Smith says:
March 16, 2012 at 4:33 pm
“By my calculation it’s about a 2.8% drop in insolation between the non-glacial and glacial states….)
Yeah, the state of the furnace at this juncture should escape no one’s attention. If the furnace goes all funky its got to mean something. It qualifies as a difficult to dismiss potential “tipping point” in my estimation.
Interesting post, but the only thing I could gleam out of the post was the world would not go into an ice age in the near future and there were vastly different time frames as to when it would happen. I hope they are right. If not the effects would be devastating.
The primary driver of atmospheric CO2 increase does not appear to be human. I say this because human CO2 emissions are highly variable. Global human CO2 emissions declined in 2009 in absolute terms (fewer tons of human produced CO2) but the rate of increase of CO2 was unchanged. I believe the primary sources of atmospheric CO2 increase are a combination of a continued warming of the abyssal deep where CO2 is released upon ventilation of deep sea water and continued anaerobic biological activity in swampy tundra-muskeg-bog areas that have been activated since glacial ice and permafrost receded since the end of the LIA.
What that means to me in the context of this thread is that if we should see a cooling of arctic areas and a refreezing of many of these swampy areas and if temperatures decline to the point where the ocean goes to net cooling, we are likely to see atmospheric CO2 decline. I have not yet seen any evidence that shows human CO2 emissions are a significant contributor to global atmospheric CO2 load. If we were, the absolute decline in human CO2 emissions should have shown a clear decline in the rate of atmospheric CO2 increase in 2009. We didn’t see any such change in rate of increase.
It takes about 700 years (I think I remember reading recently) to ventilate the abyssal deep but that is uneven, some parts are ventilated faster than that, other parts are more stagnant. But overall, temperatures are warmer these days than they have been for most of the past 700 years so I would expect net ocean CO2 degassing. Should temperatures take a significant drop *and* if ocean degassing is the primary source of atmospheric CO2 increase, we should see a rather significant drop in the rate of atmospheric CO2 rise at that time. The deactivation of bio activity in bogs due to re-freezing would have a significant impact, too, I would expect. Such a drop in CO2 can act as a feedback on temperatures in that once atmospheric CO2 begins to decline due to colder temperatures, it results in more temperature decline.
The Little Ice Age lasted about 300 years. We have been in about 150 years of recovery from it. Because of convection, it is easier to cool the ocean from above than it is to warm it. That is to say that reducing atmospheric temperature will have a faster impact on cooling overall ocean temperature than warm atmospheric temperatures will warm it. So it would probably take longer than 300 years to warm the oceans to where they were before the LIA if atmospheric temperatures were to return to where they were before the LIA, which they have not yet fully returned to yet. All of that is a round about way of saying that atmospheric CO2 rise could be nothing more than continued recovery from the LIA and that increase in atmospheric CO2 could begin to decline should temperatures decline significantly.
If the oceans do not gain back as much heat during this warm period as they lost during the LIA, the next cold period could be deeper than the LIA was as the oceans will be starting from a cooler point. In other words, we would be seeing net ocean cooling on a millennial scale (while seeing recent warming on a century scale). The next few decades will be interesting times.