This is a follow up posting to Younger Dryas -The Rest of the Story!
Guest post by Don J. Easterbrook
Dept. of Geology, Western Washington University.
The Younger Dryas was a period of rapid cooling in the late Pleistocene 12,800 to 11,500 calendar years ago. It followed closely on the heels of a dramatically abrupt warming that brought the last Ice Age to a close (17,500 calendar years ago), lasted for about 1,300 years, then ended as abruptly as it started. The cause of these remarkably sudden climate changes has puzzled geologists and climatologists for decades and despite much effort to find the answer, can still only be considered enigmatic.
The Younger Dryas interruption of the global warming that resulted in the abrupt, wholesale melting of the huge late Pleistocene ice sheets was first discovered in European pollen studies about 75 years ago. Terrestrial plants and pollen indicate that arboreal forests were replaced by tundra vegetation during a cool climate. This cool period was named after the pale yellow flower Dryas octopetella, an arctic wildflower typical of cold, open, Arctic environments. The Younger Dryas return to a cold, glacial climate was first considered to be a regional event restricted to Europe, but later studies have shown that it was a world-wide event. The problem became even more complicated when oxygen isotope data from ice cores in Antarctica and Greenland showed not only the Younger Dryas cooling, but several other shorter cooling/warming events, now known as Dansgaard-Oerscher events.
The Younger Dryas is the longest and coldest of several very abrupt climatic changes that took place near the end of the late Pleistocene. Among these abrupt changes in climate were: (1) sudden global warming 14,500 years ago (Fig. 1) that sent the immense Pleistocene ice sheets into rapid retreat, (2) several episodes of climatic warming and cooling between ~14,400 and 12,800 years ago, (3) sudden cooling 12,800 years ago at the beginning of the Younger Dryas, and (4) ~11,500 years ago, abrupt climatic warming of up to 10º C in just a few decades. Perhaps the most precise record of late Pleistocene climate changes is found in the ice core stratigraphy of the Greenland Ice Sheet Project (GISP) and the Greenland Ice Core Project (GRIP). The GRIP ice core is especially important because the ages of the ice at various levels in the core has been determined by the counting down of annual layers in the ice, giving a very accurate chronolgoy, and climatic fluctuations have been determined by measurement of oxygen isotope ratios. Isotope data from the GISP2 Greenland ice core suggests that Greenland was more than~10°C colder during the Younger Dryas and that the sudden warming of 10° ±4°C that ended the Younger Dryas occurred in only about 40 to 50. years.
Figure 1. Temperature fluctuations over the past 17,000 years showing the abrupt cooling during the Younger Dryas. The late Pleistocene cold glacial climate that built immense ice sheets terminated suddenly about 14,500 years ago (1), causing glaciers to melt dramatically. About 12,800 years ago, after about 2000 years of fluctuating climate (2-4), temperatures plunged suddenly (5) and remained cool for 1300 years (6). About 11,500 years ago, the climate again warmed suddenly and the Younger Dryas ended (7).
Radiocarbon and cosmogenic dating of glacial moraines in regions all over the world and abrupt changes in oxygen isotope ratios in ice cores indicate that the Younger Dryas cooling was globally synchronous. Evidence of Younger Dryas advance of continental ice sheets is reported from the Scandinavian ice sheet, the Laurentide ice sheet in eastern North America, the Cordilleran ice sheet in western North America, and the Siberian ice sheet in Russia. Alpine and ice cap glaciers also responded to the abrupt Younger Dryas cooling in both the Northern and Southern hemispheres, e.g., many places in the Rocky Mts. of the U.S. and Canada, the Cascade Mts. of Washington, the European Alps, the Southern Alps of New Zealand, and the Andes Mts. in Patagonia of South America.
Figure 2. Temperature fluctuations over the past 15,000 years showing the abrupt cooling during the Younger Dryas and other warming and cooling periods, the Oldest Dryas (cool), Bölllng (warm), Older Dryas (cool), Allerød (warm), InterAllerød (cool), and Younger Dryas (cool).
Figure 3. Oxygen isotope record from the Greenland ice core showing an abrupt temperature drop 12,800 years ago, 1300 years of cool climate, and sudden warming 11,500 years ago.
The Younger Dryas had multiple glacial advances and retreats
The Younger Dryas was not just a single climatic event. Late Pleistocene climatic warming and cooling not only occurred before and after the YD, but also within it. All three major Pleistocene ice sheets, the Scandinavian, Laurentide, and Cordilleran, experienced double moraine-building episodes, as did a large number of alpine glaciers. Multiple YD moraines of the Scandinavian Ice Sheet have long been documented and a vast literature exists. The Scandinavian Ice Sheet readvanced during the YD and built two extensive end moraines across southern Finland, the central Swedish moraines, and the Ra moraines of southwestern Norway(Fig. 4). 14C dates indicate they were separated by about 500 years.
Figure 4. Double Younger Dryas moraines of the Scandinavian Ice Sheet.
Among the first multiple YD moraines to be recognized were the Loch Lomond moraines of the Scotish Highlands. Alpine glaciers and icefields in Britain readvanced or re-formed during the YD and built extensive moraines at the glacier margins. The largest YD icefield at this time was the Scotish Highland glacier complex, but smaller alpine glaciers occurred in the Hebrides and Cairngorms of Scotland, in the English Lake District, and in Ireland. The Loch Lomond moraines consist of multiple moraines. Radiocarbon dates constrain the age of the Loch Lomond moraines between 12.9 and 11.5 calendar years ago.
Multiple Younger Dryas moraines of alpine glaciers also occur throughout the world, e.g., the European Alps, the Rocky Mts., Alaska, the Cascade Range, the Andes, the New Zealand Alps, and elsewhere.
Figure 5. Double Younger Dryas moraines at Titcomb Lakes in the Wind River Range of Wyoming.
Implications
The multiple nature of YD moraines in widely separated areas of the world and in both hemispheres indicates that the YD consisted of more than a single climatic event and these occurred virtually simultaneously worldwide. Both ice sheets and alpine glaciers were sensitive to the multiple YD phases. The GISP2 ice core shows two peaks within the YD that match the glacial record. The absence of a time lag between the N and S Hemispheres glacial fluctuations precludes an ocean cause and is not consistent with the North Atlantic Deep Ocean Water hypothesis for the cause of the Younger Dryas, nor with a cosmic impact or volcanic origin.
Both 14C and 10Be production rates in the upper atmosphere changed during the YD. 14C and 10Be are isotopes produced by collision of incoming radiation with atoms in the upper atmosphere. The change in their production rates means that the Younger Dryas was associated with changes in the amount of radiation entering the Earth’s atmosphere, leading to the intriguing possibility that the YD was caused by solar fluctuations.
Why the Younger Dryas is important
What can we learn from all this? The ice core isotope data were hugely significant because they showed that the Younger Dryas, as well as the other late Pleistocene warming and cooling events could not possibly have been caused by slow, Croll-Milankovitch orbital forcing, which occurs over many tens of thousands of years. The ice core isotope data thus essentially killed the Croll-Milankovitch theory as the cause of the Ice Ages.
In an attempt to save the Croll-Milankovitch theory, Broecker and Dention (1990) published a paper postulating that large amounts of fresh water discharged into the north Atlantic about 12,800 years ago when retreat of the Laurentide ice sheet allowed drainage of glacial Lake Agassiz to spill eastward into the Atlantic Ocean. They proposed that this large influx of fresh water might have stopped the formation of descending, higher-density water in the North Atlantic, thereby interrupting deep-water currents that distribute large amounts of heat globally and initiating a short-term return to glacial conditions. If indeed that was the case, then the Younger Dryas would have been initiated in the North Atlantic and propagated from there to the Southern Hemisphere and the rest of the world. Since that would take time, it means that the YD should be 400-1000 years younger in the Southern Hemisphere and Pacific areas than in the Northern Hemisphere. However, numerous radiocarbon and cosmogenic dates of the Younger Dryas all over the world indicate the cooling was globally synchronous. Thus, the North Atlantic deep current theory is not consistent with the chronology of the Younger Dryas.
The climatic fluctuations before and after the Younger Dryas, as well as the fluctuations within it, and the duration of these changes are not consistent with a single event cause of the YD. Neither cosmic impact or volcanic eruptions could produce the abrupt, multiple climatic changes that occurred during the late Pleistocene.
###
Related articles
- Younger Dryas -The Rest of the Story! (wattsupwiththat.com)
- New evidence of Younger Dryas extraterrestrial impact (wattsupwiththat.com)
- Catching up with the Younger Dryas: do mass-extinctions always need impacts? (skepticalscience.com)
- Study Finds New Evidence Supporting Theory of Extraterrestrial Impact (sott.net)
- The Great Ice Meltdown and Rising Seas: Lessons for Tomorrow (giss.nasa.gov)
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As Dr. Henrik Svensmark appears to have shown that there is a link between high cosmic radiation activity and cold weather periods on Earth, based on intervals when the Earth and the solar system were going through the spiral arms of the galaxy, where such radiation is high, I think it might be worthwhile to see if the Earth might have been transiting an unusual part of the galaxy during the Younger Dryas event.
It wasn’t, as far as we can tell. The timescale for moving through galactic arms is many orders of magnitude larger than 1000 years.
Look, I’m quite fond of Svensmark’s theory — where it is not true that he showed that there is a link between high GCR rates/solar state and climate (that was done long ago by other people) but he offered a plausible explanation for the link — GCRs create aerosols that nucleate clouds that modulate the albedo that cool the Earth, so that periods of low solar magnetic activity — correlated with high GCR rates — nonlinearly cool the earth compared to just the variation of TOA insolation that also corresponds to the low solar activity cycles. It is one of several competing explanations for the long term cycles of the planet into warm phases and ice ages, where we’ve been in an ice age for rougly 3 million years now, one expected to last several hundred million years! The current interglacial is a poorly understood bobble back to a transiently stable warm phase and is destined to end, probably end soon, unless we are lucky and the increased CO_2 in the atmosphere stabilizes us back in warm phase (a thing that sadly, I doubt will happen but one can hope on behalf of the several billion people that will die of starvation if it fails to and the cold transition is rapid).
His mechanism is proven in the laboratory, but there is a fair amount of unresolved debate about its contribution in the field. Technically, there are problems with the size of the aerosol particles produced by GCRs and the size needed to nucleate water droplets that are large enough to spontaneously grow instead of shrink (IIRC at the 50 micron boundary). I still find their argument plausible, since even smaller nucleation sites should statistically shift the threshold for cloud formation when a conditions approach the critical point where they would (almost) do so spontaneously, but it is still an open question AFAIK.
In the end, it still comes down to this — if the next 2-3 solar cycles are very low compared to the grand maximum (arguable as it is, in case Lief is listening:-) of the 20th century — at the very least a sort of local maximum at the end — then if Svensmark is correct the Earth’s albedo will increase (which it has arguably done) and temperatures will decrease by a moderately predictable amount. If the CO_2 plus high sensitivity people are right, sooner or later CO_2 will overwhelm even this effect and significant warming will resume, even if there is an albedo effect due to GCRs. If neither of them are correct and the bulk of the temperature variations is from a complex nonlinear multivariate process wherein the Earth shifts its own heating and cooing efficiency around quasi-“randomly”, then who knows what will happen? The NAO will shift phase and things will cool, or temperatures will just plain moderate and nobody will quite be able to explain why as the ocean rolls over, releasing heat (or not) laid down 1000 years ago (or not). Or the space aliens on the moon will relent and turn off their global warming heat beam that uses dark energy. Or the sun will indeed move into a different macroscopic state, but one we do not now anticipate or understand.
I might live to see this evidence come home. I might not. But either way there will almost certainly be plenty of time to transition over from a carbon-burning world economy to a solar/nuclear/etc based economy without the collapse of civilization. It will indeed be expensive, and it will be cheaper the later we wait as the technologies required are not mature. It isn’t senseless to invest limited resources in improving the technology, in part because (in my very own opinion) in the long run solar is going to be by far the cheapest way to generate energy except for fission and, if it ever is worked out, fusion, and may pass even fission. It isn’t exactly stupid to burn carbon for electrical energy, but it isn’t — again in my own opinion — even a possible basis for a steady-state human civilization, which — in my own opinion — is a worthy goal to strive for, more important than reaching the moon or mars or discovering the Higgs particle or monopoles or decoding the human genome. Right now we are infinitely vulnerable as a species to a variety of “catastrophes”, and the economic catastrophe associated with “mined”, increasingly and artificially scarce energy resources is a constant threat to civilization and economic stability.
So by all means, advance the solar hypothesis! I mostly believe it is true — there are indeed at least some very compelling correspondences in solar state and global temperature! But keep in mind that it is a hypothesis — or, in the case of Svensmark, a falsifiable theory — and is not yet proven or fully understood and that it is just one input in a complex system where CO_2 almost certainly is an important player.
A good and proper skeptic should be skeptical about their own alternative favorite explanations and should acknowledge openly that they could be wrong and the CAGW people could be right. At the moment, the fair thing to say is that CAGW is far from proven (and that a lot of the research purporting to “prove” it is suspect) but it is far from disproven as well. The next few solar cycles should be very revealing.
rgb
Thanks Gail.
That’s a hard act to follow, but:
Gail Combs says:
June 21, 2012 at 3:58 pm
“That could also explain the wiping out of the mega fauna but not the sudden freezing with buttercups still in the mouth and undigested plant matter in the stomach found in some specimens.”
=======================================================================
Since I’ve gone to a wee bit of effort to put this canard to rest let me emphasize, before we read too much into these admittedly accurate reports, we should recognize two things: the process by which these animals died and were preserved is easily described non-catastrophically; there is concordantly no evidence that they died simultaneously. –AGF
rgb says
Why 37, 32, 22 and 12 years? Why not 37, 36, 35…?
Henry says:
Why would I? If I have 4 points of measurement I can do a regression, whether linear, nat. logarithmic or binominal, and calculate everything in between, with extreme accuracy, depending how near the r2 value is to 1. Really, my approach is very basic, first year stats, I suggest you do the course.
37= average starting point 1974 of most stations
32= 1980
22= 1990
12= 2000
I would not use the results on the means as points to calculate because r2 is only 0.95. Rather use the nat. logarithmic or binominal regression on the maxima to calculate from whence we have started cooling down; r2= 0.997 and 0.995 respectively.
I said: the black value in the tables is the measured average change in degrees K per annum from the average measured IN THAT PERIOD. That means those are the coordinates before the x in the(linear) trendlines for the period indicated.. How can A BIG SCIENTIST not understand that?
You say my sample was not random and I challenge you on that. I have been sitting here with a globe trying to balance my sample according to latitude (longitude does not matter as earth rotates every 24 hours) and (on) sea – inland 70 – 30
yet you claim that my sample is not even representative of the oceans???
If you claim you trust UAH , do tell me the accuracy and precision and global representativity of those measurements?
Salvatore Del Prete says:
Since the Windows Live Spaces blogging platform was taken over to WordPress Microsoft has worked to make ‘Windows Live Writer’ 100% compatible with WordPress blogs.
Live Writer is a true WYSIWYG writing environment. What You See Is What You Get. So you can compose a comment that you’re going to put post on WUWT, (or any other WordPress blog) complete with hyperlinks, and formatting. And when you’ve got it looking the way you want it, simply click on the ‘Source’ button at the bottom left of the editor screen. And it’ll display your comment as html source code that’s perfectly compatible with the WUWT format.
If you copy the contents of that ‘source’ page and paste it into the comment block of the blog you want to comment on it’ll get the html tags right for you every time.
Windows Live Writer is free. And it can be downloaded from the Windows Live Essentials download page. And if you only want to install live writer without installing any of the other Live Essentials software you can do so.
feet2thefire says:
June 20, 2012 at 2:29 pm
agfosterjr says:
June 22, 2012 at 7:49 am
I await your easy explanation with great relish.
Steve P says
I await your easy explanation with great relish.
Henry says
me too
That means those are the coordinates before the x in the(linear) trendlines for the period indicated.. How can A BIG SCIENTIST not understand that?
. This is divided by 
. One is the temperature change. The other is the time interval over which it occurs. Temperature CHANGE is not the same thing temperature ANOMALY, although I suspect you are conflating the two — but since I can’t see your formulas, a big scientist like me has a hard time reading your mind. Imagine that.
? Are you fitting all of the data in your columns or just the last four numbers? What is the Pearson’s 
for your fits and how did you compute it? Do you even know what that is, or what assumptions underlie its use?
Change per annum is two numbers. One is
Here’s an example of the difference. Let’s make up a very short dataset:
Y T T0 (T – T0)
1 6 3 3
2 6 3 3
5 4 3 1
6 4 3 1
10 2 3 -1
11 2 3 -1
15 0 3 -3
16 0 3 -3
Here are two ways of turning it into data:
Y (T – T0) /1 (T(Y+1) – T(Y))/1
1 3 0
5 1 0
10 -1 0
15 -3 0
You’ll note that they give very different results. The first one does not plot the change in degrees per annum, it plots the anomaly for the year, which is not a derivative but a renormalized version of T(Y), the temperature. You’ve just changed the scale on which it is recorded. The second one actually computes the change in T from one year to the next, divided by the time over which the change occurs. This is a “change in temperature per year” whether relative to the average or not (the T0 cancels).
I’m guessing that you are just plotting the anomaly itself as a function of Y, (T – T0) where even the dividing by one is ignored. Or perhaps you are dividing it by Y — again, you haven’t specified. Or maybe you are doing what your words actually describe, computing the final column which is the actual change in temperature per year. Being psychic, I actually know which one. But you certainly don’t say in your document.
Let’s assume that you areally are just plotting (T – T0) as a function of the year it is computed in, the anomaly as a function of time, not the any kind of change PER anything (per being a word that literally implies a division that did not occur in your processing).
As you note — and seem to brag about — you are fitting precisely four data points with three parameters. You don’t seem to want to reply why you chose a three parameter fit. Why not four? Fit a cubic and you’ll perfectly interpolate the four points, will you not? How can you do better than that?
As for my needing to take a course. Obviously my words fell on deaf ears. I teach the course (and written my own linear and nonlinear regression routines), my friend, and you really do flunk. You aren’t even using first year stats correctly. Nor have you pointed out how you are doing the fit. What tool are you using? How does it compute
But you have, I confess, exhausted my patience. I have some real data to analyze, data worth real money. Your mistake is harmless enough because nobody is ever going to take your result seriously; I just thought you might like to learn what you are doing wrong and why your result is a very bad bet to extrapolate a few decades either way (and has almost zero predictive value). Its descriptive value as an approximation of these four data points — well, why not just plot them and let people see for themselves without a fit at all, rather than fit a meaningless curve through them? They can look and see that for the four years you select out of the 37 in the dataset, the mean goes down a bit, up a bit, then down a bit more, net descending. Since you don’t show us the other years, we cannot even judge what the natural variability of the anomaly is over the time interval in question — we have to accept whatever conclusion your four particular years lead us to. Nor can we see how well the curve you get predicts all the missing years! You might try plotting that out — you might learn something.
But I doubt that you will.
rgb
Leif Svalgaard says:
June 19, 2012 at 6:20 pm
The 10Be we measure is determined both by production [about 2 ounces per year total over the globe] and by deposition.
The fact that BE10 is also affected by deposition, does make one wonder about the accuracy of using these BE10 studies as a proxy for solar activity.
However, the very idea of increased deposition modulating the BE10 signal also suggests – to me – that there must also have been ‘clouds’, without which one could not have had increased deposition?
Henry@rgb
on
http://www.letterdash.com/henryp/global-cooling-is-here
It looks like you still do not understand that every black figure in the table is the result of a separate (linear) regression; in a row it gives 4 regression results over 4 different time spans.
… I give up ….
why don’t you at least answer my question?
If you claim you trust UAH , do tell me the accuracy and precision and global representativity of those measurements?
It looks like you still do not understand that every black figure in the table is the result of a separate (linear) regression; in a row it gives 4 regression results over 4 different time spans.
for four specific times? And what are you using for 
— is this per site?
have to do with anything (since it cancels!)?
And could that be because — you don’t say that in your article? You think? Oh, wait, I admitted that I can read your mind already. Now if you could just tell me what that means in terms of just what you actually did the the actual data, those linear regressions leading to the black figures in your columns. Presumably each of the stations consists of a long row of dated numbers, T(t). What exactly does doing a linear regression fit mean? What interval did you fit? Are the numbers a coarse grained, centered average? What were the errors for the fit? What tools did you use? How could somebody reproduce your results? How does a regression fit lead you to max and min (which I would ordinarily interpret as just being precisely that, the maximum and minimum excursion from whatever).
Nor have you addressed the points of my last post. Are you or are you not just plotting/fitting
Don’t blame me, if you please, for not being able to see what you did from a table of numbers and an obviously incorrect paragraph of non-mathematical language involving “rates” that clearly don’t exist. Or are you inferring the rates from the linear fit? If so, please provide details for how the linear fit is done — how many years do you include on either side of the centroid at which you evaluate the slope, for example? Given the slope in this manner, what does
rgb
(Aside: Tbar didn’t come through too well in the previous post — it is supposed to be “T average”, what I called T0 in a previous post).
HenryP says:
June 22, 2012 at 10:10 am
Steve P says
I await your easy explanation with great relish.
Henry says
me too
============================================================
You guys aren’t paying much attention. How many times do I have to repeat myself–I’ve treated the problem three times in this thread already–why don’t you read the link? And are you Creationists now setting Darwin up as infallible or omniscient? We’ve learned a few things since the 19th century, you know. Another thing, do you expect all the animals to die of starvation? If they don’t, they will probably die with food in their stomachs. –AGF
agfosterjr says:
“Vastly ignorant minds”, “Catastrophists”, “Creationists”; heck, you sure are fond of labels. And even fonder of using them along with your childish, small-minded name calling in ad hominems in lieu of civilized, intelligent, communication .
Do tell us; what insulting label would you like to be identified with?
Dennis Cox says:
June 22, 2012 at 2:47 pm
===================================
Call me the guy who answers questions when asked. Still waiting for your answers. –AGF
ROBERT, do you see where I am coming from? I am saying once we are in a particular regime then relatively small short lived solar variablity, won’t necessarily correspond to temperature changes, because of the stronger negative feedbacks ,inherent in the climate system once it is in a particular regime.
Sure, and I mostly agree. The difficulty is that for you to be completely convincing, you need to show me a quantitative analysis, not just make statements, and that analysis has to use numbers that have some degree of corroboration — here’s where Lief is key, as there are several (supposed) flaws in the traditional solar activity curves caused (again, not my field, I’m reciting) from changes in the way certain people made the “official” sunspot count over the decades. There is also a less than perfect correlation between solar magnetic field, as inferred from radioactive proxies, and sunspot number, where the former will be correlated with GCR modulation a lot more than JUST the former.
This has been done many times by many people, and there are some pretty good agreements, notably Maunder and Dalton on the minimum side. There is more controversy over the maxima — Ushokin (using IIRC Be proxies) concludes that the 20th century was an 8 or 9 thousand year grand maximum, explaining a lot of the anomalous heating if this general idea is correct where Lief argues that the renormalized sunspot counts no longer make the 20th century max’s “grand” — they’re high but not that high compared to the entire historical record. And Lief, if you are paying attention, I’m doing my best to paraphrase other people’s work, feel free to bop me upside the head if I go astray.
So by all means, do a formal analysis over a REALLY long time period and see if you can come up with a picture that is really convincing. Sadly, there are fluctuations up and down that don’t seem to be associated well with solar fluctuations (and that are the same order of magnitude as what is observed overall). Maunder was the best, clearest example, and remains the most compelling, but the rest of the correspondences are “messier”…
rgb
agfosterjr said:
Tom Elifritz saved me the trouble of responding to your silly strawman argument.
But point of fact, you didn’t answer their question. This is not a pseudoscience site. I’ve backed up everything I’ve said with refereed literature; all published in well respected journals. And your only response to enough peer reviewed science to keep you busy reading and studying for years if you ever had any hope at all of really comprehending what it pertains to, was to come back with impertinent straw man arguments to side step the point. And to invalidate that science, with childish personal ad hominem insults saying that it was produced by “Vastly ignorant minds”.
You failed to tell us about your own Curriculum Vitae, or how you attained such a lofty academic chair that you posses the authority to dismiss years of peer reviewed work on the stratigraphy of the Younger Dryas Boundary layer of by dozens of multiple PhD scientists out of hand. And never mind that most of them are tenured professors, and/or department heads at their respective and mostly prominent, institutions.
Clearly the only response you’re capable of in the face of volumes of peer reviewed and compelling science that violates your own passionately held Uniformitarian/Gradualist confirmation bias, and that you are unable to even read much less comprehend, is to attack the scientists, and researchers who produced, and published, it with personal ad hominem attacks.
So far, in your liberal use of straw man arguments, childish insults, and personal ad hominem attacks you’ve demonstrated the feeble logic and debate skills of a spoiled 10 year old.
Your personal opinions, or someone else’s in an article on someone’s blog come under the heading of an appeal to inappropriate authority. You’re going to need to cite some real, and pertinent papers in refereed literature.
Hopefully they’ll relate to the actual science and stratigraphic data from the YDB instead of more impertinent straw man arguments.
DC, I have not appealed once to authority, but only to facts and logic. You live in a fairy tale world of your own creation, and when challenged with problems you go and hide in your shell. You seem never to have been exposed to critical thinking or clear thinking criticism; I have laid out a series of challenges and you have ignored them all. I’d just as well argue with a flat earther as with you.
Dennis Cox says:
June 20, 2012 at 11:22 am
Some of the denials of the YD impact event are getting ludicrous.
“There can no longer be any argument that the YDB layer is in fact a global impact layer. There is only one other global stratigraphic horizon with the same assemblage of impact markers; the Cretaceous/Tertiary Boundary layer.”
A more absurd combination of ignorance and dogmatic posture we could not hope to find even from the CAGW crowd. The climate extinctionists are hopelessly deluded but they have you beat all to pieces. To repeat:
1) The likelihood of a 100my event occurring in the last 20ky is 1/5000. That would be the chances of your theory being correct if it were not absurd on the face of it.
2) No other extinction event has discriminated nearly exclusively by size. No theory explains this but overkill. Your feeble scientific background allows you to ignore entirely the simple glaring fact that Pleistocene extinctions include nothing but big game animals, but in this you have the dubious company of the extinction by climate quacks.
3) The early history of the solar system, as documented on the moon’s more ancient surface, is sharply contrasted by the situation a few hundred million years after the moon’s formation, as documented by its younger surface.
4) There is no evidence for simultaneous megafauna extinction; only for rapid extinction.
5) You have failed to address at all the distribution and timing of megafauna extinction. Why did big wombats and ground sloths die, but island mammoths did not. Human hunting, of course.
6) You fail to distinguish between independent arguments: a) evidence for periodic meteoric activity; b) evidence for Pleistocene extinction; c) evidence for DY rapid climate change. Your confounding of the three arguments is purely idiosyncratic on your part and on the part of whatever small and uniformed company you may have.
I have presented a compelling argument for human overkill, enough to leave the climate extinction proponents wholly on the defensive. You have presented nothing but nonsense and shown yourself incapable of appreciating any rationale other than that of your own invention. We’re still waiting for a single argument by way of rebuttal, something other than dogmatic assertions of faith. –AGF
RE: Robert Brown: (June 22, 2012 at 7:27 am )
“‘As Dr. Henrik Svensmark appears to have shown that there is a link between high cosmic radiation activity and cold weather periods on Earth, based on intervals when the Earth and the solar system were going through the spiral arms of the galaxy, where such radiation is high, I think it might be worthwhile to see if the Earth might have been transiting an unusual part of the galaxy during the Younger Dryas event.’
“It wasn’t, as far as we can tell. The timescale for moving through galactic arms is many orders of magnitude larger than 1000 years.”
The Svensmark theory effectively states that cooling is caused by increased cosmic radiation (or proton bombardment) from any source, galactic or otherwise. The short duration of this interval *may* be indicative of passage through a bounded region of intense fast protons. As galactic cosmic radiation is generated by multiple supernova events, passage through the expanded cloud of a single old, but comparatively recent event *might* create a intense effect of relatively short duration when compared with the time required to transit a spiral arm. That region might also include numerous small solid fragments making impact events more probable at that time.
If one can say that it is known that the Earth was not transiting any such region during the Younger Dryas period, then the Svensmark theory does not apply.
At about the 37 minute point of Svensmark’s video, “The Cloud Mystery,” it is stated that past cosmic radiation flux can be reconstructed from the state of iron meteorite fragments. Perhaps such data can be used to indicate whether or not the cosmic radiation flux was unusually high during the Younger Dryas period. I think that might better explain why this period lasted for a thousand years as opposed to the few decades that I would offhand expect from an impact event effect.
Robert Brown says:
And could that be because — you don’t say that in your article? You think? Oh, wait, I admitted that I can read your mind already.
Henry says
I don’t like your tone, as though I am the one who is stupid.
http://www.letterdash.com/henryp/global-cooling-is-here
I quote from my blog above:
method:
The (black) figures you are looking at in the tables below (allow some time to load up), represent the average change in degrees Celsius (or Kelvin) per annum, from the average temperatures measured during the period indicated. These are the slopes of the “trendlines” for the periods indicated, as calculated.
end quote.
Perhaps you don’t know what a slope is? A slope is the figure before the x in the linear equation that defines the rate of incline or decline of the plot – this equation is what we now call the trendlines. It is the rate of incline – or decline, when negative –
and in my case the dimensions of the slope are of course degrees K per annum.
anyway – – you don’t have to teach me anything and clearly you know it all- so let us leave it at that.
I am just finding it very funny that you and Roy and everybody else “‘believe” in UAH and Hardcrut and GISS etc., but cannot tell me exactly how representative those measurements are of earth and what the precision and accuracy is, and when last the equipment on board of those satellites was calibrated.
Until somebody does, I will rather believe the summaries of terrestial stations, where one can look at the differences, that you can easily pick up at each station,
i.e. my own results,
which show me that earth has started cooling down….
thank you.
It does not matter to me if nobody else believes me, because
1) science is hard work- laziness and ignorance won’t get you very far
2) science is not by consensus
3) they will feel the cold that is coming soon enough.
If you want to see an example of my analysis of a weather station I can mail you a relevant excel file.
rgrds.
Henry
agfosterjr said:
No, that’s not true at all. “wholly on the defensive?” Boy are you delusional! In fact you haven’t presented anything but your own subjective opinions, ad hominems, and straw man arguments. The fact that I refuse to dignify any of those straw man arguments with a response has nothing to do with being on the defensive. But rather, since you’re too ignorant to comprehend the nature, and content of the peer reviewed data that’s already been presented to you. There’s no point in trying to present more.
And we have yet to see a link to peer reviewed literature that successfully makes the case for human overkill. In fact, since there is no physical way to prove such a hypothesis, there is nothing at all in the literature related to it that doesn’t consist of pure speculation, and mutual-inter-assumptive confabulation.
Nothing but nonsense? My own invention? In fact, I have presented more than a dozen recent peer reviewed references describing the chemistry, and stratigraphy of the Younger Dryas Boundary Layer at locations on three continents in exhaustive detail. I didn’t “invent” anything.
The argument for Younger Dryas Impact Hypothesis is founded solely on the chemistry and stratigraphy of the Younger Dryas Boundary Layer. And the actual science of the YDB is a subject about which you are obviously completely clueless, and ignorant. What’s worse, you are in complete denial of the validity of that science without ever having read a single word of it.
The fact that you lack the intelligence to read and comprehend the science those publications present and then expose your lack of intellectual integrity by proclaiming them to all be “nonsense” is your own problem. But work that is “nothing but nonsense” rarely survives peer review to get published in major journals like PNAS, or GSA.
As I said, I have presented more than a dozen recent peer reviewed publications in major scientific journals. But since you lack the intelligence to read and comprehend what actual science I have already presented, proclaiming it to be “nonsense” without ever having read a single word of it, and since you persist in trying to fabricate a smokescreen of straw man arguments to hide that ignorance behind without providing any valid references of your own, there’s really nothing to rebut. What’s the point if you’re too dimwitted to comprehend the volumes of data that’s already been stuffed down your throat?
You haven’t provided a single reference to real peer reviewed science to support your own personal opinions, and invalidations of the refereed literature that’s already been provided. So do tell us about “dogmatic assertions of faith.”
You obviously lack the intellectual integrity to acknowledge, and intelligence to comprehend peer reviewed scientific references when provided. And since you are only capable of responding to them with ad hominem, any further debate with you is a completely demeaning waste of my time.
That is why I think solar flux is a better indicator for solar activity,since that number is much more consistent ,then the sunspot number. Everyone seems to count sunspots in a different manner.
MAUNDER MINIMUM SUNSPOTS- My guess is if we were using the equipment of today back then ,that the sunspot numbers during that period of time, would have been higher making this current period even more of a fall off in activity.
Up to this point the solar activity prior to Oct.2005 was high, the solar activity since Oct.2005 ,has been low, with the most extreme part of this low cycle yet to come.
The evidence if one looks at all the data to me is quite convining, that if the solar activity goes into a deep minimum for a long enough period of time ,that the temperatures will respond .
What is so great about this present situation we now have, is the possibility for the sun to have a GRAND MINIMUM is high, and I think if that happens we will find out just how much influence the sun has on earth’s climatic system.
The LAYMAN SUNSPOT SITE, is a great site to visit, and if one goes through the daily summaries,there are sometimes research articles attached to the end of the summary ,that support the solar/climate linkage.
Again the climate system has many feedbacks and much of the time the negative feedbacks will rule, and if the climate is in a particular regime then variations in all the items that control the climate will just result in random temperature flucuations up or down.
The temperatures when in this situation, will correspond to the item which is able to exert the most force on the climate compared to another item.
For instance if their is a SLIGHT drop off in solar activity ,and the PDO enters a warm phase at the same time ,temperatures are going to go up.
If a strong EL NINO were to develope temperatures would go up ,even if solar activity was down a little.
Until positive feedbacks from one of the sources that controls the climate is strong enough to over come the inherent negative feedbacks in the climate system ,it is going to be very hard to see how x item, effects the climate, in a convincing way.
This is why,it is so hard to come up or show a direct cause and effect. There are always competing feedbacks going on at the same time.
Dennis Cox says:
June 23, 2012 at 1:43 am
You continue to hide behind your facade of authority, and to ignore every challenge. Please tell us why the YD extinctions were purely size specific. Or if you prefer, please refer us to any literature that addresses this critical problem. This is a primary objection, and neither you nor anyone else addresses it adequately. Of course the principle problem with your claim is that no YD catastrophe or extinction in any way comparable to the K/T event ever took place–there is no evidence for it. There is simply no evidence for any YD extinction except for what is easily explained by overkill, which clearly preferred big game animals. That’s where you and your literature should start, once you pull your head out. –AGF
At about the 37 minute point of Svensmark’s video, “The Cloud Mystery,” it is stated that past cosmic radiation flux can be reconstructed from the state of iron meteorite fragments. Perhaps such data can be used to indicate whether or not the cosmic radiation flux was unusually high during the Younger Dryas period. I think that might better explain why this period lasted for a thousand years as opposed to the few decades that I would offhand expect from an impact event effect.
I don’t think the method has a resolution of Ky. It’s used on a My basis to argue for the galactic arms passages. I do not know the answer WRT radioactive proxies from the YD, but Lief probably does, and then there is the literature…
Agreed, though, that any of a number of extrinsic solar/galactic events could have been the proximate cause. They go into our common sense judgment that other explanations without them are right, decreasing their plausibility somewhat. But the simpler all things being equal explanations are still far more likely, barring specific supporting evidence of the sort you refer to.
rgb