More fatal flaws in the Shakun et al. Nature paper claiming that CO2 preceded late glacial warming [Part 2]

By Dr. Don Easterbrook

In Part 1 , I posed 11 questions related to underlying assumptions and misconceptions that form the basis for the paper “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation by Shakun et al. (Nature 2012) and discussed the first five questions related to the authors claim to have “compelling evidence that rising CO2 caused much of the global warming” and that “the CO2 change slightly preceded much of the global warming, and this means the global greenhouse effect had an important role in driving up global temperatures and bringing the planet out of the last Ice Age.”

Part 1  discussed problems related to the lack of direct dating of the Antarctic ice cores and the difficulty of accurately measuring CO2 in ice cores. In Part 2, we will look at the validity of the authors’ claims that (1) climate changes in Antarctica were out of phase with global climatic changes and Southern Hemisphere climatic changes have a ‘see-saw’ relationship with the Northern Hemisphere. These contentions are central to the whole theme of the paper. We’ll also have look at the Greenland ice cores as proxies for global climate change, the AMOC forcing as the only causal mechanism for climate change, why orbital forcing doesn’t work for the abruptness of climate changes, and if we make through all of that, we’ll look at some other causal mechanisms that the Shakun et al. paper casually dismiss.

As shown in Part 1, the lack of direct dating of Antarctic ice cores resulted in reliance on theoretically modeled, wiggle-curve correlations age estimates that are essentially just best guesses, not accurate measurements. How can we check the validity of the Antarctic ice core ages used in the paper? The nearest places to Antarctica where well-dated climate chronologies exist are New Zealand and southern South America. If the Southern Hemisphere is indeed out of phase with the Northern Hemisphere (the ‘see-saw’), we should see it also in the chronologies of New Zealand and South America. Let’s see how they compare with the Antarctic chronology. Two specific periods of climate change can be compared: (1) a late phase of the LGM ~17,000 years ago, and (2) the Younger Dryas 12,700 to 11,500 years ago. If the basic contentions of the Shakun et al. paper are correct, the chronology of these two climatic phases in Antarctic, New Zealand, and South America should be out of phase with the chronology of similar phases in the Northern Hemisphere.

New Zealand and Patagonia at the last glacial maximum

A well-defined, well dated set of glacial moraines marking the last glacial maximum enclose Lake Pukaki in the Southern Alps of New Zealand (Figure 1). Seven Beryllium 10 (10Be) age measurements of boulders on the terminal moraines average 17,400 years old (Schaefer et al., 2006; Easterbrook, 2011).

clip_image002clip_image004

10Be dates from moraines at Lake Pukaki, Glacial and pollen chronology from the

New Zealand. (Schaefer et al., 2006) southern Lake District of Chile.

LGM moraines and pollen from bogs in the Lake District of southern Chile have been extensively 14C dated. The average ages show an LGM at 17,400 years ago. LGM moraines surrounding Lago Buenos Aires in Patagonia have been 10Be dated at 16,000 and 18,800 years old (Kaplan et al., 2004).

Nineteen 10Be ages measured from boulders on moraines in the Tasmanian highlands of SE Australia range from 19,100 on terminal moraines to 15,oo0 on recessional moraines with a mean of 16,800 years. (Barrows et al., 2001, 2002).

What these well-dated chronologies are telling us is that the LGM occurred at the same time in the both the Northern and Southern and Hemispheres, i.e., the hemispheres are not out of phase with one another.

The Younger Dryas chronology

An even better climate chronology can be found during the Younger Dryas in New Zealand, which can be compared to the Antarctic YD chronology to test the Shakun et al. contentions. At least two phases of the Younger Dryas can be identified in both the Northern and Southern Hemisphere, making the YD an excellent test of whether or not the YD was synchronous in both hemispheres or was out of phase (as contended by Shakun et al.).

Southern Alps, New Zealand

New Zealand has a well-established Younger Dryas chronology at multiple localities in the Southern Alps. The YD double–moraine pattern is found in the glacial chronology at at Birch Hills along Lake Pukaki, Arthur’s Pass, Prospect Hills, Waiho Loop, and at several other localities. At Birch Hills ~40 km upvalley from the Lake Pukaki LGM moraines, 5 10Be dates from the outermost Birch Hills moraine average 12,800 years old and 4 10Be dates from the inner moraine average 11,200 years old. Another pair of YD moraines at Arthur’s Pass show a mean 10Be age of 11,800 years for the outermost YD moraine and 11,400 for the inner moraine. A YD moraine at Prospect Hills yielded 10Be dates of 12.7 and 12.8 years B.P. (Easterbrook, 2002, 2011).

On the west coast of South Island, wood in the Waiho Loop moraine, deposited by the Franz Josef Glacier about 20 km behind the LGM moraine, has been dated at 11,200 14C years (equivalent to a calendar year age of slightly less than 13,000 years). (Mercer, 1982, 1988; Denton and Hendy, 1994).

clip_image006clip_image008

Ages of Younger Dryas moraines in the Southern Alps of New Zealand.

 

clip_image010clip_image012

Ages of inner and outer YD moraines at Birch Hills in the Southern Alps.

Younger Dryas chronology in the Northern Hemisphere

At least two phases of the Younger Dryas are also well documented in the Northern Hemisphere at many localities in North America, the European Alps, Scandinavia, and eastern Europe. The chronology of these climatic events is well dated by radiocarbon. This provides the opportunity for comparison with the double phases of YD glaciation found in New Zealand and elsewhere. The double YD phases are found both in the record of continental ice sheet glaciation and in the alpine record.

Alkenone SST measurements from marine cores west of Vancouver Island indicate a temperature drop of ~3° C during the YD (Kienast and McKay, 2001). Cool-water foraminifera, suggesting YD cooling, have been found on the British Columbia shelf and in the Santa Barbara Basin. Cooling during the YD is also shown from pollen records in SW British Columbia, NW Washington, Oregon, and SE Alaska. The ages of multiple YD moraines of the Pleistocene Cordilleran Ice Sheet in NW Washington have been established by more than 100 radiocarbon dates at between 11,500 and 12,700 years old.

clip_image014 clip_image016

[A] Reconstruction of the YD phase of the [B] Ages of the double YD moraines of the

Cordilleran Ice Sheet in NW Washington Scandinavian Ice Sheet. Ages shown are 14C ages

11,500 and 12,700 years ago. equivalent to 11,500 and 12,700 years ago.

 

Alpine Glaciers

Dated YD moraines occur in the Wind River Range at Titcomb Basin and Temple Lake, and similar, moraines occur throughout the Rocky Mts. What is apparent from these examples of YD moraines is that not only was the YD climatic event recorded by alpine glaciers in western North America, but in many places double moraines record a dual YD climatic change.

Cirque glaciers expanded twice during the YD at Titcomb Lakes in the Wind River Range, WY. Erratics on moraines and glaciated bedrock ~33 km upvalley from LGM moraines at Freemont Lake, Wyoming, have been 10Be dated between 12,300 and 10,600 years old Birkeland, 1974; Zielinski and Davis, 1987; Davis, 1988; Davis and Osburn, 1987).

 

clip_image018 clip_image020

Double Younger Dryas moraines at Titcomob Ages of YD moraines in the Rocky Mts., ID

Lakes in the Wind River Mts., WY.

 

Cirque moraines at multiple elevations in the Sawtooth Range of Idaho also record two YD climatic events. Bench Lakes, north of Redfish Lake, consist of several glacial lakes at successively higher elevations, representing sequentially rising YD snowlines. The 10Be ages of boulders from range from 11,700 to 11,400 years. Thus, at least two phases of moraine building took place here during the YD.

Double, post–LGM moraines occur about 12 km upvalley from LGM moraines at Icicle Creek in the North Cascades of Washington. Boulders on the outmost YD moraine were 10Be-dated at 12,600 and 12,300 years and boulders on a younger YD moraine were dated at 11,300 and 11,900 years. All of the dates from the inner and outer moraines fall within the YD.

Double YD moraines occur at Julier Pass near St. Moritz, Switzerland and multiple YD moraines at Loch Lomond in the Scotish Highlands have been radiocarbon dated between 12,900 and 11,500 years old.

The Greenland GISP2 oxygen isotope record

The double phase of the Younger Dryas also appears in the Greenland GISP2 oxygen isotope record between 11,500 and 12,700 years ago, correlating very well with the global glacial record.

clip_image022

Double Younger Dryas event recorded in the GISP2 ice core

 

CONCLUSIONS

So what does all this mean and why is it important? The double nature of YD moraines in widely separated areas in both hemispheres suggests a common, global, climatic cause. The YD is characterized by two distinct moraines in widely separated parts of both the Northern and Southern Hemispheres and in the Pacific and Atlantic regions, indicating that the YD consisted of more than a single climatic event. This means that the twin YD cooling occurred virtually simultaneously globally and both ice sheets and alpine glaciers were sensitive to the dual YD cooling. The two YD phases in the GISP2 ice core confirm the globally synchronous climatic events. The global synchronicity of the late Pleistocene twin YD phases indicates a global atmospheric cause. The absence of a time lag between the N and S Hemispheres climatic fluctuations precludes an oceanic cause propagated from one hemisphere to the other. The sensitivity and synchronicity of worldwide climatic events with no apparent time lag between hemispheres means that abrupt climatic changes such as the YD were caused by simultaneous global changes.

So what does this mean about the validity of the contentions of Shakun et al. that the Northern and Southern Hemispheres were out of phase? Compare the age of the YD in their Figure 2 to the numerous YD chronologies from all over the world.

clip_image023

Shakun et al. Figure 2. The Red line is Antarctic temperature curve based on ice cores; the yellow dots are CO2 measurements from ice cores; the blue line is composite global temperature from 80 proxies.

The age of the YD shown on their Antarctic curve is from 13,000 to 14,700, nowhere near the age of the YD in New Zealand and the rest of the world. Considering the lack of adequate dating of the Antarctic ice cores and lack of correlation with New Zealand and global YD chronology, what this means is that their entire Antarctic curve is incorrect and needs to be shifted by nearly 2,000 years, taking with it the CO2 curve. This means that their entire argument for CO2 preceding warming during the last glaciation falls completely apart.

At this point, we haven’t yet gotten to issues with the AMOC, orbital forcing, or other possible causal mechanisms of climate change. Consideration of those issues would make this longer than most people would want to read at one sitting, so looks like they will have to await Part 3.

About these ads

70 thoughts on “More fatal flaws in the Shakun et al. Nature paper claiming that CO2 preceded late glacial warming [Part 2]

  1. 10Be dates from moraines
    I wonder a bit about those 10Be ages. The usual error on a 10Be date the last 10,000 years is +/-1000 years. The Half life of 10Be is very long, 1.4 million years, so getting a date even to with 1000 years is quite a feat. Could you expand a bit on this?

  2. Pesky facts … ;-)

    Excellent work Dr. Easterbrook. Understandable to even a layman. Which begs the question – why wouldn’t these alleged scientists look for and compare their work with known other proxies before publishing clearly erroneous conclusions?

  3. Leif Svalgaard 11:40 AM

    10Be dating measures the exposure age, i. e. how long a rock has been exposed to cosmogenic neutrons, so the long half-life of 10Be is actually helpful. The main source of uncertainty is secular changes in the amount of cosmic radiation, but this is rather well-known for the last 30,000 years or so from calibration of 14C measurements (which are similarly affected by changes in radiation flux) .
    The main problem with 10Be dates is that the local geology must be well understood. Repeated exposures and burials must be excluded.

  4. Is Carbon 14 dating valid much beyond 5000 years ago?

    Not to dispute what Dr Easterbrook is saying, but I think the data is so imprecise, that you cannot tell one way or the other.

  5. It doesn’t matter how articulate and thorough the responses & critiques from Willis Eschenbach or Don Easterbrook are, once somebody has publicly vindicated Al Gore, then the Main Stream Media will quickly shut the door on any chance at a rebuttal.

  6. tty says:
    April 18, 2012 at 12:22 pm
    The main problem with 10Be dates is that the local geology must be well understood. Repeated exposures and burials must be excluded.
    But that leaves the uncertainty at about +/-1000. Averaging several samples from the same location does not help to beat the error down as they have the same systematic error.

  7. Typo?
    A YD moraine at Prospect Hills yielded 10Be dates of 12.7 and 12.8 years B.P. (Easterbrook, 2002, 2011).
    Possibly before 1999 – possiblt A YD moraine at Prospect Hills yielded 10Be dates of 12.7 and 12.8 thousand years B.P. (Easterbrook, 2002, 2011).

    otherwise excelent.

  8. Oh that’s fantastic!
    I am sorry, but I can’t take this serious anymore as long as Mr. Easterbrook and/or Mr. Eschenbach don’t present these facts in a peer-reviewed journal. Any journal, but preferably Nature.
    That’s exactly the reason why those warmists don’t take these two gentlemen seriously, because they simply don’t have the courage to publish their rebuttals. It looks like.
    Science simply isn’t played like this what these two gentlemen try to accomplish here.

  9. Leif: where is your ±1000 yrs on recent 10be dating from? If what is being measured is the build-up of 10be, not half-life as with carbon14 in plants, why can’t it be quite accurate?

  10. 10Be dating is one among several cosmogenic dating techniques, all of which are based upon bombardment of rocks exposed at the earth’s surface by cosmic radiation that produces in-situ, stable isotopes. 10Be is produced in quartz, mostly from nuclear spallation reaction with oxygen atoms.

    The amount of each cosmogenic nuclide generated in exposed rocks depends on (1) the decay constant of the isotope, (2) the production rate (rate at which the isotope is created by nuclear bombardment, (3) the amount of time the surface has been exposed to atmospheric cosmogenic radiation, (4) any erosion rate of the rock surface since the isotopes were generated, and (5) any inherited component of the isotope concentration from earlier exposure. The buildup of cosmogenic isotopes in rock surfaces exposed to the atmosphere is a function of how long the surface has been exposed. The production rate of cosmogenic isotopes P. is given by the equation
    Px = Po e-(kx) (17)
    where Px =production rate at depth x (atm/g/yr)
    x = depth
    Po = production rate at the rock surface (atm/g/yr)
    k = a density dependent constant representing the absorption of cosmic radiation (cm 1)
    For a closed system with no surface erosion and no isotopes left from earlier events, the abundance Nx of stable cosmogenic isotopes depends upon the isotope production rate Px and time t.
    Nx = Px t (18)
    For unstable isotopes, Nx must take the decay constant of the isotope into consideration, so that
    Nx = Px (1 – e-t) -1 (19)
    Still more complicated equations can be written which include the effect of surface erosion during isotope accumulation.
    Production rates of isotopes generated by cosmic radiation have been determined by measurements in samples collected from surfaces of known age. The production of cosmogenic isotopes decreases exponentially with decreasing altitude and with depth below the rock surface because of attenuation of the cosmic radiation flux.
    In order to produce measurements that represent the time since a boulder or rock surface was first exposed to the atmosphere, the surface must have remained intact since it was exposed. However, a stringent sampling strategy can effectively minimize or avoid the effects of post-depositional processes on boulders.
    Measurement of cosmogenic isotope exposure ages offers several significant advantages over other dating methods. Perhaps the most obvious is that cosmogenic isotope dates give the age of exposure to the atmosphere and thus the time of deposition (as an erratic boulder on a moraine).
    Our recent results from the Wind River Range, Wyoming, show that total 10Be age uncertainties are ~4% including systematic errors. Total analytical reproducibility is better than 3% with multiple dates from a single landform.
    The accuracy of 10Be dating isn’t enough to distinguish the two phases of the YD individually but it is accurate enough to positively identify the age span of the pair. If we know that two post LGM moraines are both Younger Dryas that tells us that we have both phases.

  11. vukcevic says:
    April 18, 2012 at 11:49 am
    but it is more than clear there is no correlation between two.
    The correlation you do show is spurious and fails going further back in time.

  12. Robbie says:
    April 18, 2012 at 1:04 pm
    Oh that’s fantastic!
    I am sorry, but I can’t take this serious anymore as long as Mr. Easterbrook and/or Mr. Eschenbach don’t present these facts in a peer-reviewed journal. Any journal, but preferably Nature.
    That’s exactly the reason why those warmists don’t take these two gentlemen seriously, because they simply don’t have the courage to publish their rebuttals. It looks like.
    Science simply isn’t played like this what these two gentlemen try to accomplish here.

    If you had bothered to check the references you would have seen that all of this material is in fact published in a peer reviewed journal. Nature is no longer a credible journal.

  13. Robbie:

    This is a scientific blog. So, people here know that in science information is assessed on its merits and NOT on the basis of who provided it and/or where.

    Until you have learned this then go away because nobody is interested in what you – or any other scientifically illiterate – troll thinks.

    Richard

  14. Alec Rawls says:
    April 18, 2012 at 1:28 pm
    Leif: where is your ±1000 yrs on recent 10be dating from?
    Common knowledge. Check any number of papers, e.g.

    http://web.natur.cuni.cz/ksgrrsek/acta/2000/mercier.pdf

    Their Table 1:
    Sample, Altitude, 10Be exposure age± relative error (in 1000 yrs)
    G 01 1200 7.32 ± 1.31
    G 02 1180 7.97 ± 1.48
    G 03 1250 7.90 ± 1.47
    G 04 1200 4.17 ± 0.81
    G 05 1060 8.56 ± 1.53
    G 06 1040 4.14 ± 0.92
    G 07 1020 6.83 ± 1.25
    G 08 990 9.28 ± 1.83
    G 09 970 3.34 ± 0.67
    L 10 1280 3.72 ± 0.69
    L 11 1290 5.70 ± 0.97
    L 12 1335 19.20 ± 3.16
    L 13 1300 11.08 ± 1.83
    L 14 1275 8.50 ± 1.41
    L 15 1098 9.68 ± 1.67
    L 16 1095 9.00 ± 1.55
    L 17 995 12.29 ± 2.12
    L 18 970 8.74 ± 1.50
    L 19 830 12.10 ± 2.05
    L 20 828 11.53 ± 1.97
    L 21 1420 23.21 ± 3.83

  15. Vincent says:
    April 18, 2012 at 12:28 pm
    Is Carbon 14 dating valid much beyond 5000 years ago?

    It is valid back to about 35,000 radiocarbon years ago. Older records than that are extremely sensitive to contamination and should be regarded av minimum ages.
    Radiocarbon years can be calibrated to calendar years, but the calibration curves have considerable uncertainties beyond the range of tree-ring dating. Note that the uncertainty of a calibrated date is always larger than an uncalibrated. Sometimes very much larger.

  16. Leif Svalgaard says:
    April 18, 2012 at 12:46 pm

    Possibly higher depending on the inherent problems tty pointed out. Namely consistency of exposure but, I imagine the half-life depleting the buildup of 10BE is calculated in as well. Anyways, agreed, 10BE dating comes with an accuracy of about ±1000.

  17. Alec Rawls says:
    April 18, 2012 at 1:28 pm
    Leif: where is your ±1000 yrs on recent 10be dating from?
    From Abramowski’s dissertaion

    http://opus.ub.uni-bayreuth.de/volltexte/2005/150/pdf/dissua04.pdf

    page 84:
    “3.3.1 Uncertainties of cosmogenic exposure ages
    A general uncertainty of 11% is calculated to result from the present uncertainties”

    This is not my specialty, so I have only general knowledge of this, but I’m willing to learn [and measurements get better all the time].

  18. Some interesting observations about 10Be deposition uncertainties
    Perhaps most troubling of all is the cross correlation of the yearly 10Be concentration and flux measurements themselves from two sites on the polar plateau which should be observing the same 10Be production. These cross correlation coefficients are the lowest of all, less than 0.25 …..

    http://arxiv.org/ftp/arxiv/papers/1004/1004.2675.pdf

  19. Don,

    Down here in NZ there is a general consensus among those working in Quaternary deposits that the ACR is well represented in NZ, that it is an older event than the YD and that the YD is poorly expressed (if at all). Further, there is well dated evidence (not all published yet) that the ACR in NZ spans the same time interval as it does in Antarctic ice cores. While I agree with you that the Shakun et al paper is of dubious merit I think you need to have a closer look at the recent literature on deglacial events in NZ.

  20. What about a large portion of the NH biomass being scraped down to bedrock, by the glaciers, and being deposited in giant piles (I assume) waiting for a lightning strike.
    Or was the process slow enough that the tinder decomposed.
    Look at the CO2 fluxes at Mauna Loa, they are due to a flourishing NH biomass, what if it was gone ?

  21. vukcevic says:
    April 18, 2012 at 2:15 pm
    Some interesting observations about 10Be deposition uncertainties
    For once, some substance. I’ll call attention to this quote:
    “When the first detailed 10Be measurements from polar ice cores were reported (e.g., Beer, et al., 1990) there was the hope that this ice core data could provide a “monitor” of past solar activity as it effects cosmic ray intensities incident on the Earth, in much the same way as neutron monitors are used to monitor this solar activity in the modern era (Beer, 2000). This “concept” with its 1:1 correspondence between 10Be production and Be in ice cores, has since been used extensively to interpret historical 10Be ice core data in terms of changes in heliospheric conditions and their effect on cosmic ray intensities incident on the Earth. Our results show that, given our current understanding (or lack of it) of the correspondence between 10Be production, sunspot numbers and the 10Be observed in ice cores, this is really not a reliable “concept” to use for historical extrapolation. The sunspot number itself remains the best indicator of cyclic (11 year) solar activity after ~1700 A.D.

    “The level of 10Be production in the Earth’s atmosphere at the minimum of the 5 most recent solar activity cycles is the same to within 5%. If this production level has changed in the past, then the present uncertainties in the 10Be ice core data are such that the magnitude of these changes cannot be robustly determined. Calculations also show that if the LIS [local interstellar flux] remains the same as it is now, the 10Be production should never increase by a factor of more than 1.3-1.5 over the average modern values at sunspot minimum at any time in the recent past, whereas increases by a factor ~2.0 have been observed in the 10Be ice core data.

    “more than 50% of the 10Be flux increase around, e.g., 1700 A.D., 1810 A.D. and 1895 A.D. is due to nonproduction related increases.” [e.g. Climate Change that determines deposition]

    This undermines all the glorious correlations between solar activity and climate that people consider Gospel Truths. This is such a problem that a special workshop will be convened in a couple of weeks to consider all this: http://www.leif.org/research/Svalgaard_ISSI_Proposal_Base.pdf
    Perhaps in month’s time we can say more.

  22. tty says:
    “It is valid back to about 35,000 radiocarbon years ago. Older records than that are extremely sensitive to contamination and should be regarded av minimum ages.”

    I agree with you, but just note that many people are publishing dates back to more than 50,000 years BP using accelerator mass spectrometry (AMS).

    Also, speleothem studies have been used to extend C14 calibration curves beyond that of dendro.

  23. Leif Svalgaard says:
    April 18, 2012 at 2:52 pm (Responding to )

    vukcevic says:
    April 18, 2012 at 2:15 pm
    Some interesting observations about 10Be deposition uncertainties
    For once, some substance. I’ll call attention to this quote: … (trimmed)

    And thus we make progress. 8<)

  24. My quick layman’s perusal regarding the 10Be accuracy seems to show that there has been considerable work done on exactly the issue Leif raises and that there are regional calibrations using reliable paleoclimate data available for many (most?) of the well studied areas, that take in to account the variabilities, thus greatly increasing the accuracy.

    Greg Balco seems to be a main player in the 10Be issue, with his online calculator seeming to be a widely used tool for basic work, and his later publications continuing to improve on the accuracy:

    http://depts.washington.edu/cosmolab/pubs/gb_pubs/pubs.html

    Balco G., 2011. Contributions and unrealized potential contributions of cosmogenic-nuclide exposure dating to glacier chronology, 1990-2010. Quaternary Science Reviews. 30, pp. 3-27 (invited review paper) PDF

    http://depts.washington.edu/cosmolab/pubs/gb_pubs/Balco_QSR_2011.pdf

    Balco G., Briner J., Finkel R.C., Rayburn J., Ridge J.C., Schaefer J.M., 2009. Regional beryllium-10 production rate calibration for late-glacial northeastern North America. Quaternary Geochronology 4, pp. 93-107. PDF

    http://depts.washington.edu/cosmolab/pubs/gb_pubs/balco_QG_2009.pdf

    Balco G., Stone J., Lifton N., Dunai T., 2008. A simple, internally consistent, and easily accessible means of calculating surface exposure ages and erosion rates from Be-10 and Al-26 measurements. Quaternary Geochronology 3, pp. 174-195.
    PDF: http://depts.washington.edu/cosmolab/pubs/gb_pubs/balco_QG_2008_authorcopy.pdf
    Link to online exposure age calculators:

    http://hess.ess.washington.edu/

  25. I pointed out in earlier threads that the Taylor Dome (Antarctic) cores shown close agreement with the Greenland ice cores on YD dating. Which at minimum throws significant doubt on the dating of the Antarctic ice cores Shakun uses.

    http://depts.washington.edu/isolab/taylor/

    I’d add that if NH and SH cooling events were as separated as other Antarctic ice cores show (1k years), then that throws serious doubt on a globally distributed GHG such as CO2 having an important role in them.

  26. To have a systemic error of almost 2,000 years in ice core data is mind-boggling. Not unimaginable, but one would have had to give the benefit of some error questions to the Other Side.

    The comment of Rob about NZ glacial events: he is saying that the YD of the Northern Hemisphere has a slightly older brother in the Southern Hemisphere that is being confused with the YD? That, too would be mind-boggling. But not unimaginable.

    What is certain? Other than taxes, of course.

  27. Can’t wait to Part 3.

    I have always contended that we need to listen to the geologists.

    Thank you sir for all your hard work.

  28. A. Scott says:
    April 18, 2012 at 3:54 pm
    Greg Balco seems to be a main player in the 10Be issue, with his online calculator seeming to be a widely used tool for basic work, and his later publications continuing to improve on the accuracy
    The issue is whether his work was used in Don’s piece. From the time of the cites, it doesn’t like like it.

  29. “Leif Svalgaard says:
    But that leaves the uncertainty at about +/-1000. Averaging several samples from the same location does not help to beat the error down as they have the same systematic error.”

    Leif, given that the IPCC measures global temperature to 14 decimal places, are you really sticking with that statement?

  30. A. Scott says:
    April 18, 2012 at 3:54 pm
    My quick layman’s perusal regarding the 10Be accuracy seems to show that there has been considerable work done on exactly the issue Leif raises

    Thanks for the Balco links [very educational]. Nevertheless, Balco (2011) states that:
    “The total systematic uncertainty in production-rate scaling schemes is approximately 10%. For Lateglacial moraines between ca 10,000 and 15,000 years old, a 10% uncertainty is 1000e1500 years. [...]
    To summarize, the fact that software tools now make it relatively easy to compute exposure ages with a wide range of scaling schemes and production-rate calibration data sets highlights the importance of scaling uncertainties. Currently these scaling uncertainties preclude correlation of exposure ages derived from the current global production-rate calibration data set with independently dated climate events at millennial scale. ”

    So it seems the ±1000 years are still with us.

  31. I think that you should revise your posts a little (after your third post) and submit them in a single letter to the editor of Nature. The worst that could happen is that they refuse to acknowledge the letter, so send it registered. Then report back to us what happens.

  32. The chronology of the Younger Dryas doesn’t depend solely on 10Be dating. The 14C chronology, which is much more accurate (+/- 50 yrs in 10,000), is also widely used to date the Younger Dryas. 14C dating is in good agreement with the 10Be chronology in New Zealand and many other parts of the world.

  33. Leif:
    You are absolutely right. I see systematic errors, and systematic errors being compounded in much of the warm-earther “science”. It is a shame that statistical methods do not seem to be prerequisite in much of the climate science. I just can’t tell if it is intentional or inadvertent.

  34. Don J. Easterbrook says:
    April 18, 2012 at 9:24 pm
    The chronology of the Younger Dryas doesn’t depend solely on 10Be dating.
    But in your piece the dating is nevertheless overwhelmingly 10Be-based

  35. Thanks! I’ve hiked through the moraines at RedFish lake many times. Absolutely beautiful area. Everywhere you bother to look in the Stanley basin you see remnants from the last ice age.

  36. Robbie says:
    April 18, 2012 at 1:04 pm
    That’s exactly the reason why those warmists don’t take these two gentlemen seriously, because they simply don’t have the courage to publish their rebuttals. It looks like.
    Science simply isn’t played like this what these two gentlemen try to accomplish here.

    Apparently you didn’t read the cliamtegate emails, where well known climate scientists are conspiring to keep competing papers out of peer reviewed journals?

    Thus we have the birth of sites such as WUWT where rebuttals and papers can receive open peer review.

    Sort of like the software industry, where unix is the open source alternative to microsoft. In this case WUWT is the open source equivalent of unix, while Real Climate and the Team are the closed source equivalent of microsoft.

    Thus we have WUWT voted #1 science blog, while RC is well below Steve McIntyre’s Climate Audit! A one man outfit auditing climate science as a hobby outgunned the Team – supposedly the top climate scientists in the world – at least in their own minds – time and time again shown to be playing a rigged game.

    If climate science is so sure of its facts, why the need to rig peer review? Why risk cheating if you have a winning hand? If you are holding aces, it is plain stupid to deal off the bottom of the deck and risk being found out. No one would do it, unless they knew the aces were phoney.

  37. UNFCCC established/funded “science” to support the political.established UNFCCC,
    It’s mostly politics and less science.

    It does not matter if it’s not science. What matters is that it is UNFCCC conform and that only. It will be in the comming AR5 for shure.

  38. Alarmists know very well that there is no evidence for their theories on ‘global warming’ in the geological record. This is a real problem for CAGW fanatics.

    The Shakun et al paper was one of the first real attempts to try and demonstrate alarmist theories were correct by using the geological record.

    The Shakun observations about the Antarctic ice cores had to be wrong; the real question now is whether this was deliberate or not. Their explanation for how rising CO2 levels supposedly preceded increasing global temperatures at the end of the last Ice Age was little more than a highly unlikely example of wishful thinking.

    Circa 12,000 years ago, the oceans warmed up (a reflection of one of the regular natural climate cycles that have occurred during the last 2.6 million years), which released carbon dioxide – this is the only possible explanation for what happened.

    Be that as it may, Shakun et al will undoubtedly be a gospel fact for AR5 – as already noted several times here – despite being convincingly shredded by Anthony, Willis and others.

  39. Dr. Easterbrook – one of the other things I came across was the reminder c14 dating is for carbon based organic material … In some cases, such as preserved wood buried in sediment, it would be relevant to depositional time … But in other cases such as lichenometry the date measured would be for stabilization timeframe, in the studying recall, that being appx 1300 years after deposition.

    I would guess this is well known and taken into account but thought it worth at least noting…

    Hope I got all that correct from memory :-)

  40. Jeef says:
    April 19, 2012 at 6:25 am
    Leif, for someone who says this isn’t a speciality you sure have a lot to say!
    Cosmic Rays do fall within my specialty. Geology is on the fringe, but my probing elucidates the topic for myself and the many others not having this as a specialty. Learning something is always good. I hope you learned something too.

  41. The fundamental question that arises in my mind if you propse a model in which CO2 leads temperature and is therefore the culprit in warming out of an ice age is – how do you get back to an ice age again? All that CO2 causing the warming has to disappear to somewhere, or the mechanism causing ice ages has to be much stronger than the CO2 effect. If its the latter, then the CO2 is irrelevent. If its CO2 that is the cause and not the effect, what causes CO2 to cycle?

    I think an argument proposing CO2 leads not lags is a tautology becasue I cannot see a plausible mechanism for ice ages.

  42. ThinkingScientist says:
    April 19, 2012 at 7:13 am
    because I cannot see a plausible mechanism for ice ages
    The changes in the Earth’s orbit and orientation caused by planets, sun, and moon [Milankovitch cycles] change the solar insulation at high northern latitudes and are usually considered a plausible mechanism for glaciations.

  43. ThinkingScientist says:
    ………..
    2010 AGU Fall meeting
    Abrupt Climate Change During the Last Ice Age
    Presented by D. A. Hodell, Earth Sciences, University of Cambridge

  44. Hi Don
    I’m afraid that the recent research shows that the Younger Dryas was mainly a Northern Hemisphere event (see Kaplan et al. 2010).

  45. LeifSvaalgard says:

    “The changes in the Earth’s orbit and orientation caused by planets, sun, and moon [Milankovitch cycles] change the solar insulation at high northern latitudes and are usually considered a plausible mechanism for glaciations.”

    I am a geoscientist by training. I understand this mechanism which I have always understood to be the reason for ice ages and inter-glacials. My point concerns the idea that CO2 increase lead temperature increases and therefore causes the warming. If this were true, then the implication is the CO2 effect is large and overwhelming and the Milankovitch effects are small. IF this were true then I cannot see how, once you have a CO2-led warming out of an ice-age into an inter-glacial period how you can possibly get back to ice-age again. If the CO2 effect were larger than the Milankovich effect then you need another mechanism to (a) return to ice age and (b) reduce the atmospheric CO2. That effect has to be EVEN BIGGER than the putative CO2 effect that led you out of an ice-age.

  46. Robbie,
    “I am sorry, but I can’t take this serious anymore as long as Mr. Easterbrook ….”
    I looked him up and found Don J. Easterbrook, PhD, Professor Emeritus of Geology,Western Washington University.
    Should you not accord Dr. Easterbrook his correct title? Over here in Europe he would not be called Doctor but Professor. I suspect that applies in the States as well but that he is too modest to publish under that title.

  47. Ha ha ha ha….. Robbie

    Why would any serious Climate Researcher want to submit their work to Nature???
    A more respectable journal would Publishers Clearing House.

  48. Thinking scientist has a good point.

    If CO2 is much stronger than the cycles how could we ever get back to an ice age ?

  49. Thanks NetDr.

    Nice to see that thought just hanging there waiting for a response….anyone?

  50. One of the Shakun authors spoke at AMS in Portland a few weeks ago. During the Q&A he was asked about a graph shown during the talk. With the slide back up on the screen, the author was queried on one portion of the time series, to which he was flummoxed. He had to be prompted from the Questioner that this was what is known as the ‘Younger Dryas.’ The audience was stunned.

  51. “”””” tty says:

    April 18, 2012 at 2:01 pm

    Vincent says:
    April 18, 2012 at 12:28 pm
    Is Carbon 14 dating valid much beyond 5000 years ago?

    It is valid back to about 35,000 radiocarbon years ago. Older records than that are extremely sensitive to contamination and should be regarded av minimum ages. “””””

    I have a piece of wood; several pieces in fact, that have been radio carbon dated as being 45,000 years old; that figure having been obtained in at least two credible carbon dating labs, and they quite routinely date other wood samples at from 30,000 to as much as 55,000 years old. These are wood samples taken from buried forests that look like what you could find down at your local lumber yard.

    The measurement processes are considerably more sophisticated, and sensitive than the earliest carbon 14 dating methods. But yes they are sensitive to the variability of the carbon 14 years due to cosmic ray flux variations.

  52. George E. Smith; says:
    April 19, 2012 at 6:05 pm
    But yes they are sensitive to the variability of the carbon 14 years due to cosmic ray flux variations.
    Which in turn are mostly due to the [poorly known that far back] variation of the Earth’s magnetic field.

  53. George E. Smith; says:
    April 19, 2012 at 6:05 pm
    ………..
    Hi George
    And you may ask: how did the Earth’s magnetic field change?
    We have a reasonable estimate of changes for the last 8000 years.

    http://www.vukcevic.talktalk.net/GMF-8Kyr.htm

    Keen climate sceptic would be able to identify (delta Bz, red line) Roman, MWP & LIA periods. Rise of the ancient civilisations: Mesopotamian (3500 BC), Egyptian Old Empire (3000BC) and New Empire (1500BC), China (2000 BC), Japanese and Mayan (0 AD) may be just another coincidence.

  54. Still no response to this question:

    If CO2 is much stronger than the cycles how could we ever get back to an ice age ?

  55. ThinkingScientist says:
    April 20, 2012 at 9:00 am
    Still no response to this question:
    If CO2 is much stronger than the cycles how could we ever get back to an ice age

    The obvious answer is that the cycles are stronger, but that does not mean that other effects are nil.

  56. ThinkingScientist says:
    April 20, 2012 at 9:00 am
    Still no response to this question

    I you offering a research grant?
    I could design a CO2 oscillating model based on proliferation (and devastation) of oceanic phytoplankton and calcium-carbonate organisms, the largest consumers of the atmospheric CO2; sort of periodic semi-self-extinction by over-consuming the existential resource, whereby organic rocks are formed during inter-glacial. Milankovic cycle would then be only a synchronising trigger signal rather then a driver.

  57. To LeifSvaalgard: That is the common sense answer. A simple, practical, rational model that doesn’t require extra parameters/causes etc to wrok.

    To Vikcevic: No prizes I’m afraid in the form of grants. I could also structure a model of the type you describe based on some form of anti-persistence and solicit grants etc etc. But we already have a simple model that explains ice ages quite well – unless some primary evidence comes along to contradict an excellent theory, why “invent” another one?

    To both, the bottom line re: ice ages is Occam’s Razor applies. There is a an excellent, rational theory all ready in place that seems to do quite a good job, but the competing theories (“CO2 leads temp etc etc”) all have major flaws when faced with a simple back of the envelope reality check. The only way around this is to create extra parameters to somehow fix the problems. This lis like the old earth-centric view of the universe, but in reverse. The helio-centric model (Milankovich) came first but now people are desperately trying to find earth-centric models (CO2 leads temperature) and as a consequence have to explain why outer planets appear to have to loop back on themselves. Its just absurd.

  58. Leif Svalgaard says:April 19, 2012 at 7:53 am
    ThinkingScientist says:
    April 19, 2012 at 7:13 am
    because I cannot see a plausible mechanism for ice ages

    “The changes in the Earth’s orbit and orientation caused by planets, sun, and moon [Milankovitch cycles] change the solar insulation at high northern latitudes and are usually considered a plausible mechanism for glaciations.”

    Analysing the frequencies of the temperatures from the dO18 data you can find a simple mathematical relation of the 3 known Milankovitch frequencies, but 15 more (last row Log F)

    F = n^2 * 0.00265157

    F_n = 1^2 * 0.00265157 = 1/377.13 ky -2.38
    F_n = 1.25^2 * 0.00265157 = 1/241.4 ky -2.58
    F_n = 1.5^2 * 0.00265157 = 1/167.1 ky -2.22
    F_n = 1.75^2 * 0.00265157 = 1/123.1 ky -2.09
    F_n = 2^2 * 0.00265157 = 1/94.2 ky -1.97
    F_n = 2.25^2 * 0.00265157 = 1/74.94 ky -1.87
    F_n = 2.5^2 * 0.00265157 = 1/60.34 ky -1.78
    F_n = 2.75^2 * 0.00265157 = 1/49.86 ky -1.70
    F_n = 3^2 * 0.00265157 = 1/41.90 ky -1.62
    F_n = 3.25^2 * 0.00265157 = 1/35.70 ky -1.55
    F_n = 3.5^2 * 0.00265157 = 1/30.78 ky -1.49
    F_n = 3.75^2 * 0.00265157 = 1/26.81 ky -1.43
    F_n = 4^2 * 0.00265157 = 1/23.57 ky -1.37
    F_n = 4.25^2 * 0.00265157 = 1/20.87 ky -1.32
    F_n = 4.5^2 * 0.00265157 = 1/18.62 ky -1.27
    F_n = 5^2 * 0.00265157 = 1/15.08 ky -1.18
    F_n = 6^2 * 0.00265157 = 1/10.47 ky -1.02
    F_n = 7^2 * 0.00265157 = 1/7.69 ky -0.89

    See. Fig. 4 from Berger et al.:

    http://imageshack.us/f/444/bergerfig4.jpg/

    Because of this strong mathematic connection of 18 stable oscillators of different strength over more than 500 ky with a maximum temperature step of +8K of n=2 , while the change in the Milankovitch cycle of 94.2 ky is minimal, it seems to be to a joke to speak on ‘plausible mechanism’, it’s pure fanatasy and bad science.

    V.

  59. Volker Doormann says:
    April 27, 2012 at 3:37 pm
    it’s pure fanatasy and bad science.
    I agree with this your own admitted assessment of your extreme cyclomania.

  60. Leif Svalgaard says:
    April 27, 2012 at 9:24 pm
    Volker Doormann says:
    April 27, 2012 at 3:37 pm
    “Because of this strong mathematic connection of 18 stable oscillators of different strength over more than 500 ky with a maximum temperature step of +8K of n=2 , while the change in the Milankovitch cycle of 94.2 ky is minimal, it seems to be to a joke to speak on ‘plausible mechanism’, it’s pure fanatasy and bad science.”

    I agree with this your own admitted assessment of your extreme cyclomania.

    Well, it is written: “The English suffix -mania denotes an obsession with something; a mania. The suffix is used in some medical terms denoting mental disorders. It has also entered standard English and is affixed to many different words to denote enthusiasm or obsession with that subject. – An obsession is defined as a compulsive preoccupation with a fixed idea or an unwanted feeling or emotion.”

    Leif Svalgaard says: “The changes in the Earth’s orbit and orientation caused by planets, sun, and moon [Milankovitch cycles] change the solar insulation at high northern latitudes and are usually considered a plausible mechanism for glaciations.”

    This thread is a thread on the world’s most viewed site on global warming and climate change, and has arguments to the saw tooth like functions of the cycles or better frequencies of three analyzed frequencies of 1/94.2 ky^-1 , 1/41.2 ky^-1 and 1/23.57 ky^-1 found in many deepsea samples in the Atlantic ocean and in the Antarctica (Vostok).

    But these three frequencies are not the only proxy frequencies in the samples; it is easy to show (s. prior posting) that there are about 18 frequencies or cycles to be analyzed in the history of the Earth back 800 Million years BP. The fact, that Milankovitch has calculated the same frequencies out of the astronomical functions of the solar system suggest that there is a geometric relation between the three cycles in the samples and the astronomical functions in the solar system, but it does not mean that – as you teach the world – ‘are usually a plausible mechanism for glaciations (plural), or a causality of a known physical process.

    There is no (!) plausible mechanism for glaciations (cycles of glaciations), because the onset of the global warming is about 10 kyears prior to the maximum temperature, and the long linear decreasing time takes about more than 80 kyears. This is in contradiction to the sinusoid like functions Milankovitch has computed out of the astronomical functions. Moreover, because the three frequencies or cycles have a square relation of n (2,3,4) on a fundamental frequency, like all analysed frequencies have on integer numbers or fractions of ½ or factions of ¼ with a clear decreasing function of the amplitude with higher integer numbers, this indicates a multiple saw tooth like oscillator with frequencies of 1/377ky^-1 to ~ 1/10ky^-1 in general and the difference between the Milancovitch cycles and the analysed cycles in the Atlantic cores is the number (3 : 18).

    You may teach the world that this difference is scientifically diagnosed by you as an ‘extreme cyclomania’ which you can show as an authority in medical science.

    The simple truth is that you have not replied on the strong geometric relations which Milankovitch has taken (3) from the astronomical functions in the solar system and which I have shown simple in extension in number and/or fractions (18), but replying only on my saying on fantasy and bad science, because of your claim on ‘plausible mechanism’, without explaining with plausible (!) arguments what the physical mechanism is heating up the Earth +8K for long times and which holds on until today with all that known effects.

    Bad science.

    V.

  61. Volker Doormann says:
    April 28, 2012 at 3:48 am
    Well, it is written: “The English suffix -mania denotes an obsession with something; a mania. The suffix is used in some medical terms denoting mental disorders.
    Describes cyclomania quite well, I would think.

  62. Leif Svalgaard says:
    April 28, 2012 at 5:43 am

    Volker Doormann says:
    April 28, 2012 at 3:48 am

    Well, it is written: “The English suffix -mania denotes an obsession with something; a mania. The suffix is used in some medical terms denoting mental disorders.”

    Describes cyclomania quite well, I would think.

    Blog policy, OT.

    EOD

Comments are closed.