Younger Dryas -The Rest of the Story!

WUWT readers may recall this recent story: New evidence of Younger Dryas extraterrestrial impact The story below provides much more detail about the Younger Dryas event and the split that has developed in the scientific community over the cause. I’ve added this graph below from NCDC to give readers a sense of time and magnitude of the event. – Anthony

The Younger Dryas cold interval as viewed from central Greenland. From:
Quaternary Science Reviews Volume 19, Issues 1-5, 1 January 2000, Richard B. Alley

Guest Post By: Rodney Chilton www.bcclimate.com

A consideration of many other very important factors that should be considered as well as the “Black Mats and Nanodiamonds”

ABSTRACT:

The genesis of the Younger Dryas stadial (cold interval) remains an enigma. The onset was both climatologically unexpected and extremely sudden. The two principle theories are diametrically opposed and the proponents of both deeply committed. The debate to date has primarily been centred on some unusual “black mat” deposits that may or may not be linked to a cosmic origin. What has been lacking in the wider discussion are all the other important features associated with the Younger Dryas. The following addresses many of these, in hopes of their inclusion in future debate.

AND NOW THE REST OF THE STORY:

The Younger Dryas onset remains a little understood event. The cause of the 1,300 year-long interval continues to be debated. There are two completely different theories that have split the scientific community. One group strongly endorses an overall slowing or complete stoppage of the Northern Atlantic Ocean circulation 13,000 years ago. The other camp maintains that a catastrophic event originating from the cosmos was the cause.

Following on the heels of the mostly milder Bølling and Allerød intervals (interstadials), there was an extremely sudden and severe climate reversal, this was the Younger Dryas, first detected from Danish pollen studies as long ago as the mid 1930’s. Pollen from the Dryas flower, an arctic species lends its name to this very cold interval. The Younger Dryas cold was first thought to have been confined to north-west Europe, with a possible extension to some other localities immediately surrounding the North Atlantic. More recently however, the cold climate shift is seen as world-wide in extent or nearly so.

The Younger Dryas appeared similar to earlier events known as Heinrich events that were prominent in the Pleistocene (approximately 70,000 to 14,000 years ago) (1). Their cause is not altogether clear, but marine cores, primarily in the north-east Atlantic are festooned with layers of sand, pebbles and rock (lithic materials). These deposits arrived in this area carried on “large armadas” of ice that upon melting deposited their lodes onto ocean bottoms. Rapid climate shifts have been linked to ice melt from sea ice and the large continental glaciers that surrounded the North Atlantic. Lower salinity meltwater is less dense than ocean water and tends to float as a freshwater cap over the marine waters, and this is perceived as associated with North Atlantic Ocean circulation disruption. The Younger Dryas is understood to be linked primarily with meltwater almost solely from the great continental ice sheets.

North Atlantic Ocean circulation has been likened to a great ribbon-like conveyor belt (2). Driven by temperature (thermo) and salinity (haline) differences, the thermohaline (THC) circulation is associated with the formation of North Atlantic Deep Water (NADW). The sinking of the NADW is alleged to result in the drawing north of warmer waters from southerly climes. This provides north-west Europe with its generally mild climate. However all of this is thought to change when the North Atlantic Ocean circulation slowed or stopped.

It has been proposed that a sudden immense amount of fresh water disrupted the THC approximately 13,000 years ago, and the most likely source was eastern North America’s Laurentide Ice Sheet (3). This particular scenario is presumed to have been affiliated with the relocation of freshwater outflow that had been exiting via the Mississippi River with entry into the Gulf of Mexico. Presumably, an alternate route, the more northerly St. Lawrence corridor became available as the Laurentide Glacier retreated (4). As time has passed however, this idea has largely been abandoned. Not only did salinity levels in the off shore waters adjacent to the St. Lawrence remain the same during the Younger Dryas (5), but the St. Lawrence route remained blocked by ice until well after the Younger Dryas ended (6).

Failure of the St. Lawrence River to deliver the melt has lead to alternative freshwater routes proposed. One of these involves the continent of Antarctica. The idea suggested here is that a significant increase in meltwater entry into world oceans took place approximately 14,300 to 14,600 years ago (7). An inundation known as “meltwater – pulse 1a” (mwp-1a) occurred with perhaps as much as 90% of the meltwater volume originating from Antarctica (8). This premise has the Antarctic melt as affecting the North Atlantic region, but with a significant delay (the bipolar see-saw concept where at least Antarctic climate is out of phase with the Northern Hemisphere). The eventual arrival of the Antarctica melt waters is seen then, as making the North Atlantic vulnerable to even modest amounts of meltwater (9). Presumably, the final threshold was crossed 13,000 BP, allowing the North Atlantic to become disrupted (10). Not all researchers share this view, as at least one study assigned a much different date for mwp-1a, and that was shortly before 13,800 BP (11). And although these scientists also conclude slowing or shutdown of the North Atlantic, the Antarctic as a source becomes questionable.

Since the Antarctic theory appeared, a number of other possible North Atlantic meltwater sources have been suggested. The first of these considered meltwater from the Laurentide as flowing northward through the Canadian Arctic via the Hudson Strait before reaching the North Atlantic (12). A second route was proposed more recently, and this was freshwater flowing across Arctic Canada from the main Laurentide source, Lake Agassiz, then down the Mackenzie River and into the Arctic Ocean (13). The first of these meltwater corridors has now been shown to have remained blocked by ice throughout the early Younger Dryas, much like the St. Lawrence (14), and the second pathway, the Mackenzie, required adjustments to both the Laurentide Ice Sheet and the underlying landmass, before model simulations even allowed meltwater flow to take place (15).

As just mentioned, the main Laurentide meltwater source originated in the huge glacial lake, Agassiz. Most research has indicated that there was a significant lowering of the lake approximately 13,000 years ago. The assumption to date has been that most of the water exited by one corridor or another. However, recent research has suggested that Lake Agassiz may not have experienced very much rapid outflow at all. Dr. Thomas Lowell of the University of Cincinnati contends that lake lowering resulted primarily from open lake evaporation when the lake was ice-free and some sublimation when it was frozen (16). However, this too has been disputed by another study that questions the very high rate of evaporation that the Lowell findings contend; this at a time when the climate was presumably very cold (17). The scientists who criticized the evaporation idea however fall back on the now implausible St. Lawrence meltwater route (18).

Certainly a very important question regarding the Younger Dryas is what effects, if any, were felt elsewhere in the world (away from the immediate confines of the North Atlantic). There are some indications that one outcome was similar to the most recent Heinrich event, specifically a warming of one to two degrees Celsius in the western tropical Atlantic and the Caribbean (19). The reason given for this warming is evidence of a response to strengthened easterly trade winds, which causes greater amounts of warm water to be driven into the Gulf of Mexico (20). Well to the west, on the north coast of South America the same stronger trade winds may also have induced ocean upwelling (21).

The evidence for the greater ocean upwelling is increased ocean productivity within the Cariaco Basin (22). However, the very premise of a trade wind induced warmer Caribbean and western tropical Atlantic during the Younger Dryas is now seen as suspect. Recent studies have shown that south-east portions of North America, the Caribbean and western tropical Atlantic all became much drier and colder at this time (23,24). Central America, for instance, shows a 300-400 metre lowering of the subalpine tree line. This is equivalent to a two to three degree Celsius temperature decrease (25). A number of other studies also indicate colder temperatures.

One of the more important proxies comes from the Orca Basin within the Gulf of Mexico. This is a very interesting study, dependent upon the assessment of certain specific marine organisms. This has allowed scientists to make some startling conclusions. An organism, Globigerinoides Ruber (a species tolerant of high salinity and cold ocean temperatures), when compared to five other marine species less tolerant of cold and high salinity depicted a sudden change in the Orca Basin ecology 13,000 BP (26). Originally, the Orca Basin was thought to have become much more saline, the result of a sudden diversion of meltwater from the Mississippi to the St. Lawrence corridor. However, the eastward meltwater route has now been shown to have been implausible. Instead, it now appears that the Orca Basin experienced a five or six degree drop in ocean temperature. (27). This has recently been confirmed by a new study that depicts significantly colder SST occurred within the Orca Basin region (28). All of this is consistent with a meltwater pulse continuing down the Mississippi and not flowing into the St. Lawrence.

It is interesting too, that the Younger Dryas is now seen has being a widespread event that extended well beyond the North Atlantic. The cold and predominately dry interval is now documented from all across North America and northward as far as Alaska. South America also experienced a definitive climate shift to a predominately cold and arid regime. This included the Amazon Basin, covering a significant portion of the tropical and subtropical latitudes of South America. Indications of an extreme drop in Amazon River levels to as little as 40% to 60% of present day levels are evident (29). Lake Junin (11° S), a high elevation lake in the northern Andes is a second proxy showing an arid Younger Dryas, as lake levels were at their very lowest for the last 14,000 years (30). Not only did the climate become drier, it appears to have become colder too. Certainly the two to three degrees Celsius cooling, in Colombia is an indicator (31). The aforementioned very low Amazon River level may well have been a response to decreased snowmelt and run-off from a colder Andes mountain chain.

Further to the south in the Altiplano region (15° to 23° S), the climate during cold intervals like the Younger Dryas is expected to be wet (32). However, 13,000 years ago there appears to have been an exception (33). Indications are from the glacier Sajama (18° S) that a retreat of the glacier occurred, much as Glacier Quelccaya had done a little further to the north (both likely responding to a drier and colder habitat) (34). Further, considering once again the very low Amazon water levels, the Altiplano source region also appears to have been experiencing a decrease in precipitation.

Aside from a study from the Great Australian Bight (32° –35° S) (35) and an area near the edge of Antarctica (36) where distinct cooling was evident 13,000 years ago, the remainder of the Southern Hemisphere does not show a definitive warming or cooling trend.

Antarctica, at least the interior portions of the continent, may well be a different matter entirely. Here, the analysis of ice cores depicts a climate out of sync with the rest of the planet. Research suggests that very strong downslope (katabatic) winds prevent weather (climate) from penetrating any appreciable distance inland (37). However, it must be said that conclusions as to the Antarctic climate during the Younger Dryas are far from certain. There are problems having to do with the generally very light snowfall that is a feature of Antarctica.. This prevents researchers from accurately differentiating climate intervals of less than about 2,000 years (38).

One type of methodology that permits past climate to be assessed depends upon the analysis of various gases that become trapped within ice after being deposited as snow within ice sheets throughout the world. The worldwide dispersion of most gases only takes one or two years, this allows comparisons of relative gas concentrations in localities as far apart as Greenland and Antarctica. The alignment of ice cores from low snowfall Antarctic and higher snowfall Greenland permits scientists to differentiate past climate. The problem is that it takes many years for the gas to be completely sealed off from the present day atmosphere. This varies between low snowfall areas like Vostok in Antarctica, where it takes as long as 2,500 to 6,000 years to “close off’ (depending upon the age of the ice deposit) to about 60 to 100 years in Greenland cores (39). The technique, while very good in determining the longer-term glacial and interglacial periods, at least in Antarctica is clearly inadequate for shorter-term events such as the Younger Dryas.

The continued contention that the North Atlantic was the principle trigger of the Younger Dryas has relied heavily upon a number of marine cores from the Atlantic. The first of these cores comes from the Bermuda Rise (EN120GGC1 – (33° 40’ N., 57° 37’ W)), where the analysis of benthic profiles of carbon 12 and 13 isotopes, along with cadmium/calcium ratios theoretically shows North Atlantic Ocean circulation disruption (40). However, a number of problems have been identified that relate to the Bermuda Rise marine core. Before analysis could be done a comparison was required with another marine core, CH73-139C (54° 30’ N., 16° 21’ W.), a core now found to have been affected by a condition called “bioturbation” (an unwanted mixing of the marine sedimentary layers) (41). This prevents precise dating as to the time when the slowing or stoppage of the ocean circulation occurred (42). A second problem with the samples from Bermuda Rise is its location. Rather than sampling the desired amounts of deep water from the North Atlantic and Antarctic, it appears to be sampling an area where a localized mixing of ocean waters took place, that once again prevents accurate assessments (43).

The marine species Neogloboquadriana pacyderma, a polar organism displayed a definitive shift in population approximately 13,000 years ago, both at a marine core, Troll 3.1 (60° 47’N., 03° 43’W.), just west of Norway, and a second core V23-81 (54°02’N., 16° 08’ W.), just off Ireland’s west coast (44). Both of these studies have been drawn upon to deduce that a slowing or complete shutdown of the North Atlantic Ocean circulation occurred 13,000 BP. A third study, that utilizes diatoms, (much more sensitive than Neogloboquadriana pacyderma), is very likely more appropriate in discerning relatively brief cold intervals such as the Younger Dryas (45). This study from the South-east Norwegian Sea does show a definitive shift of five to six degrees Celsius. However, that may or may not necessarily be attributable to North Atlantic circulation disruption (46). The following quote highlights the researchers caution when they stated, “there is evidence that cooling was related to reduced salinities, but this does not prove a direct causal relationship that cooling was directly forced by meltwater events” (47). The shift instead may simply have been the result of changes in the relative number of polar and arctic organisms (48).

The inference drawn is that cold intervals such as the Younger Dryas may well have another altogether different trigger than North Atlantic Ocean circulation. Further to this, a somewhat more recent paper, also by the same researchers that conducted the study in the Norwegian Sea indicates, that a reduction in incoming solar radiation might be the trigger that initiates fluctuations in the polar front in the Nordic Seas (49). It is very intriguing that a reduction in incoming solar radiation may have occurred at a time when during the summer a maximum of solar energy should have been occurring (see ref. 75).

The whole concept of North Atlantic Ocean circulation as having any appreciable influence upon the Younger Dryas is placed further in doubt by the work of Dr. Michael Sarnthein. Dr. Sarnthein has collected a large number of marine cores from throughout the Atlantic sampling the interval back to 30,000 before present (BP).

The conclusion gleaned from his work reveals that the North Atlantic Ocean circulation was operative during the Younger Dryas, and had been so for more than 1,500 years prior to the start of this cold period (50). This is consistent with one other high-resolution marine core from the South Atlantic (presumably a good location to detect North Atlantic shifts) that does not show a slowing or shutdown of the North Atlantic (51).

Oceanographer Dr. Carl Wunsch has gone so far as to suggest that the whole concept of a temperature and salinity induced ocean circulation shift is in error, at least in the North Atlantic (52). Dr. Wunsch also believes that the North Atlantic is simply too small to cause significant climate changes in other parts of the world (53). Dr. Wunsch was even more emphatic about the role of the North Atlantic in climate changes when he stated that “you can’t turn the Gulf Stream off as long as wind blows in the North Atlantic” and then goes on to say that “the conveyor is kind of fairy tale for grownups”(54). Dr. Richard Alley seems to echo these sentiments when he questioned how the small high latitude North Atlantic “energy starved polar tail” could possibly “wag the large energy rich tropical dog”(55).

Apart from this, the presence of a less dense freshwater cap may not result in what many scientists see as a cooling at all. Instead, Dr. Richard Fairbanks sometime ago suggested that the presence of a shallow freshwater lid over more saline waters might be subject to rapid warming during the summer and early autumn (56). Thus, instead of the commonly perceived shift to cold associated with the presence of freshwater within the North Atlantic may well result in warming. This of course is the exact opposite of what many scientists currently believe occurred during the Younger Dryas. All of this presumes that there may have been a less saline North Atlantic at this time. However, according to many scientists there was an absence of meltwater entering world oceans approximately 13,000 BP, thereby making this scenario unlikely.

There are in addition a number of other perplexing factors apparent during the Younger Dryas: Carbon 14 (14C), for instance, increased markedly by 70% to 80% at the very beginning of the cold interval (57,58,59). This far exceeds the expected 30% or 35% 14C increase when the North Atlantic allegedly slows or shuts down (60,61). The consideration of possible 14C increases from geomagnetic changes or increased sea ice coverage are also thought to be quite insignificant (62). A second element, Beryllium 10 (10Be), also increased significantly approximately 13,000 years ago. Snowfall at this time in Antarctica and Greenland was much reduced, and it is this that some scientists see as the cause for higher 10Be concentrations (63). The contention is that the snow that did fall removed as effectively the beryllium from the atmosphere, thereby resulting in higher concentrations within ice. However, an alternative view is seen as plausible, and that is simply that there was much more 10Be in the atmosphere during the Younger Dryas (64,65). Both of these elemental forms are known to be products of cosmic events that therefore lend credence to the Impact Hypothesis.

Two other deposits within Greenland and Antarctica glacial ice display interesting characteristics as well. Nitrates are one of these, and though very difficult to analyze, there appears to be little doubt that much of the increase 13,000 BP was attributable to very high amounts in the atmosphere (66,67). A second deposit, ammonium, was also greatly elevated during the Younger Dryas. The predominate origin for Younger Dryas ammonia that arrives in Greenland is North America, and one reason proposed for very high levels is that biological activity remained very prominent because of a continuation of a mild climate (68). However, it is now known that North America did become significantly colder at this time, therefore making greater biological activity extremely unlikely. Thus, there are more questions than answers about the possible origins of the elevated levels of both nitrates and ammonium.

Even more intriguing, and more controversial as well, are a number of other deposits found both in soil and ice, possibly linked to a cosmic origin (69). Associated with an unusual “black mat” deposit found in many of the terrestrial sites, the dates for this layer are very close to the 13,000 BP Younger Dryas beginnings (70). What has garnered most of the attention thus far, are features called “nanodiamonds.” One way in which nanodiamonds are produced is under very high temperatures and pressures (consistent with a cosmic origin). Scientists such as geologist Dr. Allen West contends that approximately 13,000 years ago “ a low density object” entered the Earth’s atmosphere, disintegrated explosively, and the remnants of the catastrophe rained down upon the planet (71). The signatures (including nanodiamonds)of this event were left behind throughout a widespread area that includes Europe, the Greenland Ice Sheet and North and South America (72,73,74).

Another perplexing feature of the Younger Drays is that it was a time of increased solar insolation during the summer months. Solar receipt during summer months when received associated with “June perihelion.” Somewhat surprisingly, it is the summer months that are most critical to snow and ice being retained from one year to the next at the Northern Hemisphere high latitudes (75). This particular alignment has occurred forty-two times over the past one million years and the Younger Dryas is noted as the only significant cold interval (76).

Two final features to be noted about the Younger Dryas, is that it took hold, not in decades as was once thought, but rather in as little time as a few years, or even less (77,78). This is but another piece of the puzzle that does not fit with the whole premise of an ocean induced short-term cold climate interval. It may be concluded that an alternative hypothesis, that of a very large cosmic event took place not that far from Earth, 13,000 years ago. All things considered, the evidence that supports this cosmic origin is available in much greater detail elsewhere, though a number of scientific papers are referenced here.

Concluding Remarks:

Despite all of the preceding discussion as to its numerous shortcomings, the North Atlantic Ocean circulation as cause for the Younger Dryas, remains the most widely accepted hypothesis. During the past several years, however, a debate on what is seen by many as a much more plausible trigger, one that involves either a very close comet passage or even a possible impact event that had transpired. To date, the primary focus in attempts to justify a cosmic origin for the Younger Dryas has been almost totally limited to black mat deposits (specifically nanodiamonds), that have been detected in various parts of the world. This is far too limited an approach!

It is the purpose of this paper to attempt to raise the profile of the long list of other very important clues that also require consideration. An in conclusion, a list of many of the most important aspects are listed as follows:

  1. The North Atlantic Ocean circulation (known as the THC) slowing or shutdown was not triggered by meltwater suddenly shunted down the St. Lawrence, nor was it likely to have flowed north through Arctic Canada. Nor was the continent of Antarctica involved in Younger Dryas forcing.
  2. Furthermore, dating of significant meltwater entries into the world’s ocean have not been shown as contemporary with the Younger Dryas onset.
  3. The main marine cores drawn upon as evidence for the THC hypothesis have either proven to be unreliable, or in some other cases only circumstantial.
  4. And in contrast, with the just mentioned marine cores, are the proxies collected by Dr. Michael Sarnthein that depict the North Atlantic Ocean circulation as operative during the Younger Dryas and much as 1,500 years before the interval, as well throughout the Younger Dryas. In fact, the North Atlantic appeared to have been operative as much as 1,500 year before the start of the interval, and continued right on through the period as well.
  5. Increases of both 14C and 10Be are much too large to be associated with the North Atlantic Ocean circulation disruption.
  6. Also, as time as gone in it is becoming increasingly evident that the onset of the Younger Dryas was indicative of atmospheric origins for the event, in that the onset was so very rapid, perhaps in one year or less.
  7. Finally, it should also be stated that such an extraordinarily severe and long-lasting event occurred at a time when glacial and sea ice expansion took place despite a peaking of solar radiation in the most critical summer months.

Acknowledgements:

My thanks to Steve Garcia and Clint Unwin for their valuable suggestions, and thorough editing of the foregoing paper. Also to Reed Kirkpatrick for keeping me apprised of some specific subject areas.

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60) M. Legrand and S. Kirchner, “Origins and Variations of Nitrates in South Polar Precipitation,” (1990): Journal of Geophysical Research 95, 3493-3507.

61) K. Fuhrer and M. Legrand, “Continental Biogenic Species in the Greenland Ice Core Project Ice Core: Tracing Back the Biomass History of the North America Continent,” (1997): Journal of Geophysical Research 102 C12, 26735–26745.

62) R.B Firestone et al., “Evidence for an Extraterrestrial Impact 12,9000 Years Ago that Contributed to the Megafaunal Extinctions and the Younger Dryas,” (2007): PNAS 104 #41, 16016-16021.

63) Heather Pringle, “Firestorm from Space Wiped out Prehistoric Americans,” (2007): New Scientist 8-9.

64) Ibid.

65) R.B Firestone et al., “Evidence for an Extraterrestrial Impact 12,9000 Years Ago that Contributed to the Megafaunal Extinctions and the Younger Dryas,” (2007): PNAS 104 #41, 16016-16021.

66) W.C. Mahaney et al., (2010) “Evidence from the North-western Venezuelan Andes for Extraterrestrial Impact: The Black Mat Enigma,” http://www.science.com

67) A.V. Kurbatov et al., “Discovery of a Nanodiamond – Rich Layer in the Greenland Ice Sheet,” (2010): Journal of Glaciology 56, 749-758.

68) B. Molfino and A. McIntyre, “Nutricline Variation in the Equatorial Atlantic Coincident with the Younger Dryas,” (1990): Paleoceaography 5, 997-1008.

69) Ibid.

70) J. P. Steffenson et al., “High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in a Few Years,” (2008): Science 321, 680-683.

71) K. Ravillious” Ice Age Took Hold in Less than a Year,” (2009): New Scientist, 10.

Rodney R. Chilton, a climatologist for the past thirty years, is interested in a number of nature’s mysteries, including the enigmatic Younger Dryas. The author resides on southern Vancouver Island, British Columbia, Canada.

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crosspatch

Well, that was something of a disappointment. Read through the whole thing and it turns out to be basically “we have no idea what caused it”.

Olaf Koenders

And there you have it – evidence of paleolithic SUV’s from space..

Luther Wu

Thank you, Mr. Chilton.

crosspatch says:
“Read through the whole thing and it turns out to be basically ‘we have no idea what caused it’.”
But we can make an educated guess: CO2 caused it!
What else could it be?
.
[/sarc] <—shouldn't be necessary. But there it is.

otsar

Great paper. Thank you.
Very readable update on the present level of knowledge about the Younger Dryas.

I do think that Crosspatch has missed the point of my submission, as I was attempting to point out the huge weaknesses in the THC (North Atlantic slowing or shutdown) hypothesis. While at the same time I am asking that the discussion regarding the cosmic signals be greatly expanded from just he Black mat deposits and the nanodiamond concentrations. Also. my thanks Anthony for posting my submission

mysteryseeker

I do think that Crosspatch has missed the point of my submission, as I was attempting to point out the huge weaknesses in the THC (North Atlantic slowing or shutdown) hypothesis. While at the I do think that Crosspatch has missed the point of my submission, as I was attempting to point out the huge weaknesses in the THC (North Atlantic slowing or shutdown) hypothesis. While at the same time I am asking that the discussion regarding the cosmic signals be greatly expanded from just he Black mat deposits and the nanodiamond concentrations. Also. my thanks Anthony for posting my submissionsame time I am asking that the discussion regarding the cosmic signals be greatly expanded from just he Black mat deposits and the nanodiamond concentrations. Also. my thanks Anthony for posting my submission

mysteryseeker

Sorry this is what I meant to say: I do think that Crosspatch has missed the point of my submission, as I was attempting to point out the huge weaknesses in the THC (North Atlantic slowing or shutdown) hypothesis.While at the same time I am asking that the discussion regarding the cosmic signals be greatly expanded from just he Black mat deposits and nanodiamond concentrations to great many other intersting factors present at the beginning of the Younger Dryas. Also, my thanks Anthony for posting my submission.

otsar

The parts I have never liked, and find unsettling, about the Younger Dryas are: that it occurred fairly recently, that the onset was in years, and that we do not have a solid understanding of what produced it.

GuarionexSandoval

Or that it was a high current Z-pinch aurora triggered by a coronal mass ejection resulting in severe atmospheric disturbances, not limited to fires on a global scale in the Northern Hemisphere, and a high enough influx of radiation to mortally wound large terrestrial mammals, at least in the northern latitudes.

A. L. Peratt, J. McGovern, A. H. Qöyawayma, M. A. Van der Sluijs, and M. G. Peratt, Characteristics for the Occurrence of a High-Current
Z-Pinch Aurora as Recorded in Antiquity Part II: Directionality and Source, Trans. Plasma Sci. v.35, n.4, 2007

Other papers here: NEAR EARTH MANIFESTATIONS OF THE PLASMA UNIVERSE
This is from Anthony Peratt at Los Alamos National Laboratories, not from those who have modified his ideas and posted them on what he calls anti-science websites.
“What has garnered most of the attention thus far, are features called “nanodiamonds.” One way in which nanodiamonds are produced is under very high temperatures and pressures (consistent with a cosmic origin).
But the formation of nanodiamonds is also consistent with the electrical discharges associated with high current aurora.
The northern latitudes would have been bombarded with protons and the southern latitudes with relativistic electrons. Either of these should have altered atmospheric chemistry in predictable but different ways that should be detectable in ice cores from around that time.
To date, the primary focus in attempts to justify a cosmic origin for the Younger Dryas has been almost totally limited to black mat deposits (specifically nanodiamonds), that have been detected in various parts of the world. This is far too limited an approach!
Peratt and associates have cataloged petroglyphs from around the world in both hemispheres that reproduce with considerable accuracy the plasma instabilities that would have been visible at the time in such an aurora. The forms of the drawings are such that they demonstrate a change in geometry that is consistent with the latitude at which they are found, a change that would be expected if artists at different latitudes were copying such a fixed globally visible phenomenon. But more important was an anomaly in their distribution that went unexplained until the discovery by the THEMIS satellite of a breach in the earth’s magnetosphere A. L. Peratt, W. Fay Yao, P. Bustamante, and R. Tuki, The THEMIS magnetospheric breach discovery and an anomaly in the global distribution of petroglyphs; MHD instabilities recorded by mankind in antiquity, Spring Meeting American Physical Society, Denver, Colorado May 2-5, 2009.
The abstract below:

The THEMIS Magnetospheric Breach Discovery and an Anomaly in the Global Distribution of Petroglyphs; MHD Instabilities Recorded by Mankind in Antiquity ANTHONY PERATT, Los Alamos National Laboratory, W. FAY YAO2, Albuquerque School System, P. BUSTAMANTE3, UC en Concervacin, R.TUKI, National Council Indigenous Development — The recent THEMIS spacecraft discovery of two very large holes in the Earth’s magnetosphere helps explain an anomaly in the global distribution of petroglyphs on our planet [1]. Previously, we reported a world wide GPS logging of some 4 million of these objects, each a picture of a filamental MHD instability carved in rock [2,3]. In all cases, the field-of-view of the petroglyphs was true south with an off-horizon inclination between 21-31 degrees. However, in a complete survey of the braided lava tube caves on Easter Island, petroglyphs were also found in long, true-north shafts, 50m or more in length. This observation had been noted in natural shafts of similar lengths in the Columbia River Basin. 1. W. Li, to be published in the Journal of Geophysical Research. 2. A. L. Peratt et al, Trans. Plasma Sci 35. 778. 2007. 3. A. L. Peratt and W. F. Yao, Physica Scripta, T130, 2008.
1 Library and Technology Division
2 Santiago, Chile
3 Easter Island, Chile

I know that fieldwork has been ongoing since 2010, but I haven’t yet heard the results.

etudiant

A good paper.
It would have been nice to have included a bit more evidence that the temperature drop was abrupt,
but it reads like science as it ought to be, evidence is weighted and hypotheses are tested against the evidence.
Just because we have not been able to piece together all the clues to provide a satisfactory understanding of the event is no reason to be disappointed.
Imho, just the gradual recognition that this was a world wide event, not just something localized to northern Europe, is a major step forward.
Similarly, the strong evidence from this that colder means drier should help refute the more common ‘global warming = spreading deserts’ claims.

Fraxinus

I wonder how much of an effect the other large lakes present in the Northern hemisphere could have had? They are much less studied in the English language literature, mostly due to their location in the former Soviet block. It is known that there was a significant proglacial lake in western Siberia, and I believe in Poland at the time of the Younger Dryas.
I also know that the shift from draining Lake Agassiz into the Mississippi to draining through the St Lawrence was not accomplished in a single step, portions of the Laurentide Ice sheet melted and drained into the Susquahana and Hudson Rivers for long enough to carve notable canyons.

A very interesting read. Thanks, Dr. Chilton, Anthony.

Joachim Seifert

We clearly see that the Cosmic Impact proponents are slowly
but surely gaining ground, providing more and more evidence……
……whereas the Ocean Streaming storyline tellers are unable
to put additional prove on their scales….Fact, see above: They lose
one argument after the other…..
JS

Neville

Well we don’t know what caused it, but do we know what caused the rapid temp increase that ended the younger dryas?
http://www.ncdc.noaa.gov/paleo/abrupt/data4.html
This abrupt temp increase of 10c in a decade occuring in Venezuela and Greenland at the same time must also be very unusual?
I just wish that someone here could give a suggestion for this huge temp increase over such a short time span.
BTW makes our modern warm period of 0.7c in the last 100+ years look a bit wimpy at best. Also the mod WP comes at the end of a minor ice age, so what would we expect?

R Barker

Very interesting puzzle. But, hey, if you want the science settled, figure out what you want the answer to be and then call in “The Team”. :<)
Considering all the confounding issues raised with each piece of evidence offered to explain the Younger Dryas event, it is quite remarkable that AGW forecasts can be made and believed with such high levels of confidence. On the other hand, the catastrophic consequences of AGW are always vague and forever just a few years away. Just enough to energize the believers, pressure the politicians and keep the government money flowing.

Bennett

I found it to be a fascinating read and well worth the time I spent. Thank you Mr. Chilton, and thank you Anthony for giving Mr. Chilton a podium to present his work.

edward

IMO, the discussion about the YD event is talking about the cart before the horse. If one can explain the climatic phenomenon that occurs roughly every 1200 yrs throughout the glacial cycle, then one is ready to discuss the YD event. The NH (GISP2) shows such a fast rate of temp increase preceding the YD event, which we misinterpret as the entering of the interglacial, but which IMO is just another of the 1200 yr cycles, with it’s switch like behavior, jumping up 12-15 degrees, and then a jumping down (same rate like a switch) back down 12-15 degrees (and sometimes doubled up like at 45kyr, 38kyr and the precursor to the YD event, and also like the switch like jump up after the YD event, followed by the subsequent long slow entrance rate into the interglacial. You can see the long slow background rise into the interglacial behind the spike that occurs before the YD event. If the preceding ramp up to the YD event was long and slow, like the Vostok entrance into the interglacial, or the rate which occurs after the recovery from the YD event, and the dropout occurred, then I would say the YD event is the anomaly. IMO, the 1200 yr spike is the anomaly, unexplained and not understood, and without the understanding of what is “forcing” this switch like behavior, one cannot possibly understand what happens when this forcing is removed. Someone, please explain the incredible rate of temp increase that occurs at the recovery from the YD, and the subsequent return to the normal slow rate of interglacial entrance, and why the fast rate matches all of the previous 1200 yr spikes in the glacial record.
http://s852.photobucket.com/albums/ab89/etregembo/?action=view&current=GISP2_Vostok_50K.jpg
Questions:
1. What causes the 1200 yrs transients, with their fast ramp up and ramp down rates (much faster than the normal rate entering and exiting the interglacials.
2. Is the abnormally fast entrance rate into the interglacial, either before or after the YD event, depending upon ones interpretation, actually the entrance into the interglacial, or an unfortunate 1200yr transient, with it’s switch like behavior, making the YD event look so anomalous(riding on top of the slower rate entering the interglacial)?
Inquiring minds want to know…
P.S. Not saying the meteor didn’t occur, or possible glacial lake releases didn’t happen, just that the event is likely misinterpreted due to the lack of understanding of the 1200 yrs spikes that dominate the glacial period in the NH (GISP2) with their incredible ramp rates at both entrance and exit.
It’s like understanding oceanic cycles (PDO/AMO/ENSO) before subtracting them from the temperature record beforing analyzing residuals…like the sun and CO2 or Cosmic Rays or whatever floats your boat.

Somewhat surprisingly, it is the summer months that are most critical to snow and ice being retained from one year to the next at the Northern Hemisphere high latitudes (75).
Why should this be surprising?
You don’t mention the Taylor Dome cores, which show Antarctic synchronization with NH Younger Dryas.
https://geoweb.princeton.edu/people/bender/lab/downloads/Steig_et_al_1998_copy.pdf
But very interesting. Thanks very much for this summary. Science is about exploring uncertainty. A point that seems to be lost on the AGW crowd.

Steve B

There is a much simpler story although it doesn’t specify a cause.
The beginning of the Younger Dryas where the temps dipped is when Noahs flood occurred. The end of it where temps went back up is below.
Gen 10:25 To Eber were born two sons: the name of the one was Peleg, for in his days the earth was divided, and his brother’s name was Joktan.
It was during the time of Peleg that temps warmed and sea levels went up. This is when he land bridges were inundated. There is approx a 400 yr gap between the flood and Peleg and it all happened 4500 – 4000 BP.
Now the flaming begins 🙂

Well, that was something of a disappointment. Read through the whole thing and it turns out to be basically “we have no idea what caused it”.
That is what real science is like sometimes. Very darned interesting.
If something big passed through our solar system at that time, might it not be observable today? A rapid increase in C-14 and Be-10 indicates a near by energetic event, a VERY energetic event. What would be other indications of such an event.
Those are good questions to ask.

Gregory Ludvigsen

To add to GuarionexSandova comment, a popularexplaination of the electric universe is set out in “Magnetic Reversals and Evolutionary Leaps: The True Origin of Species”, by Robert W. Felix, including the black layer, the diamonds and the temperature drop.

P Wilson

There are so many theories. About the comet theory: It is speculated that the effect of a comet on atmospheric nitrate, and a estimates of its consequence for atmospheric ammonium, providing a test for the occurrence of a bolide at the onset of the Younger Dryas. Comets break down N2 in the atmosphere to nitrate (NOx), increasing nitrate concentration. Greenland cores do show ammonium increase at the onset of the YD – when nitrogen and hydrogen form ammonia, and the hydrogen would have come from the ice sheets. Its pure speculation whether it was a bolide forcing or a freshwater forcing, but in either case, it would only be a short lived affair – a sudden spike. Yet the YD was a millenia-long event….
no one ever seems to question the internal thermodynamics of the earth, as to whether there might be a hot spot in the earth’s core that causes sudden big freezes, mainly in the northern hemisphere, in what seems to be almost precise timescale resolutions on the temperature reconstruction of the last several hundred thousand years

Mike M.

thank you very much for posting. i have a scientifically minded teen and have used this article to demonstrate “the way science is done”.

William Abbott

If a comet entered the atmosphere it might account for a large influx of “melt”water. Perhaps causality is cosmic. Maybe the comet’s “melt”water was massive and caused a thousand year suppression of the N Atlantic circulation.

Looking at the GISP2 data, Colder is dustier.
http://www.gisp2.sr.unh.edu/DATA/fancy.html
I’ve been arguing that the recent Arctic sea ice melt is caused by increased solar insolation + decreasing surface albedo from particulate deposition.
When you have multiyear accumulation of ice, glaciers or sea ice, dust and other particulates are embedded in the ice. Solar insolation melts (and sublimates) ice from the top, resulting in accumulation of this material on the ice surface progressively decreasing albedo. A positive feedback.
This appears to me to be a plausible mechanism for rapid warming from periods of extensive ice cover, such as the end of the Younger Dryas.

commieBob

Ice age – What ice age?
Here’s a link to a really skeptical article: http://www.blavatsky.net/science/atlantis/emails/ice_age.htm There is ‘evidence’ that the ice ages, as we understand them, did not happen.
The first thing that attracted my attention when I found the above link was the name Blavatsky. “Verrry interesting” The new age movement might be termed “Blavatsky for dummies”. In other words, although I do not personally have the knowledge and skill to refute the information and conclusions in the above linked article, I’m darn sure it’s garbage. It is, isn’t it? Help …

Tim Minchin

Every day taht passes I’m being proven more correct. The Younder Dryas event was in fact the destruction of Atlantis. It is chronicled in Otto Mucks amazing book the Secret of Atlantis. The chesapeake bay craters are the remnants of this = The sargasso sea eel migrations are also proof.

davidmhoffer

commieBob;
I’m darn sure it’s garbage.
>>>>>>
It is worse than garbage. The article rests upon this argument:
********************
A first and perhaps prime fact you need to know is that ice does not go uphill. Water doesn’t and ice doesn’t and glaciers don’t. Even over level ground ice doesn’t go very far. Specifically it goes up to 7 miles on level ground. Ice just can’t push ice further than that. If pressure is applied to push more than 7 miles worth of ice then it gets crushed or melts instead.
A look at the map shows that the ice would have to be pushed much farther than 7 miles.
With just this info you can see, the ice-age didn’t happen!
********************
An “ice age” happens when the total amount of snow that falls in winter exceeds the amount that melts in summer. If that happens over a large area, you get a large ice sheet, it doesn’t have to “travel” to get anywhere. As for the 7 mile limitation, it all depends on speed. If the ice only moves a small amount year over year, then no crushing or melting occurrs. FAIL on the first two points of the article, no further reading required to conclude that it is drivel.

<i.commieBob says:
June 16, 2012 at 7:21 pm
It’s nonsense. It confuses mountain glaciers with continental icesheets (and various other things). With radar sensing we now know that both Antarctica and Greenland contain large below sea level basins. Ice keeps accumulating in these basins until it overflows the surrounding mountains.
http://en.wikipedia.org/wiki/File:Topographic_map_of_Greenland_bedrock.jpg

William

The Younger Dryas type abrupt cooling event is a cyclic event. A extraterrestrial impact cannot cool the planet for a 1000 years. An extraterrestrial impact is not cyclic.
The Younger Dryas is a Heinrich event. I have looked at cause of the Heinrick in detail. They are caused by a pseudo cyclic interruption to the solar magnetic cycle. There is as I have noted before abrupt changes to the geomagnetic field that coincide with abrupt climate change events. A interruption to the solar magnetic cycle is the serial abrupt climate changer. The abrupt change to geomagnetic field affects planetary temperature by Svensmark’s mechanism. The affect of on the geomagnetic is dependent on the orbital parameters. The interglacial periods have all ended abruptly. There are cycles of this peculiar Heinrich events in the paleoclmatic events in the paleorecord.
Obviously there are other possible phenomena that will leave high temperature burn marks on the surface planet.
There are a suite of different astronomical anomalies that are explained by what is the source of this cyclic solar change. What is observed explains for example the spiral galaxy rotational anomaly, the extreme high temperature gas that occurs in intergalactic space between galaxy clusters, (basic calculations indicate the very high temperature gas should have cooled, there is no mechanism that can heat the gas to the temperatures observed or can heat such a large volume on intergalactic gas) the long term cyclic increasing radiation from quasars (there is no physical explanation for what can cause the quasar radiation to cyclically change on periods of a year and to increase in magnitude with time. The radiation increases in magnitude until there is an event the resets the cycle) , magtars, quasar redshift morphological changes, the reason why “black holes” have a maximum mass of around 10^10 solar masses) the lack of spiral galaxy redshift morphological changes and so on. (i.e. When very large objects collapse what forms is not a black hole but rather a physical object that is unstable that changes with time. Think of a galaxy with a large number of these objects. The massive “black” hole that is the source of quasar radiation is just a very large example of one of these very large objects.
As one cannot in a lab create the conditions in a “black” hole is assumed. There are series of paper that discuss both the quasars observations that are not explained by the standard model (classical black hole and with a dust rotating dusk disk. For example naked quasars, quasars that emit radiation but do not have a dusk disk, and the observation of a massive magnetic field that occurs above the quasar, and so on.) and the physics of the objects that form in an extremely large object collapse.
It appear the solar magnetic cycle has been interrupted. If it has, I will start a thread to explain what is observed.
http://www.annualreviews.org/doi/abs/10.1146/annurev.energy.30.050504.144308
ABRUPT CHANGE IN EARTH’S CLIMATE SYSTEM
Abrupt shifts between warm and cold states punctuate the interval between 20 to 75 ka) in the Greenland isotope record, with shifts of 5◦–15◦C occurring in decades or less (Figure 1). These alternations were identified in some of the earliest ice core isotopic studies [e.g., (22)] and were replicated and more precisely dated by subsequent work (23). Further analysis of diverse records has distinguished two types of millennial events (13). Dansgaard/Oeschger (D/O) events are alternations between warm (interstadial) and cold (stadial) states that recur approximately every 1500 years, although this rhythm is variable. Heinrich events are intervals of extreme cold contemporaneous with intervals of ice-rafted detritus in the northern North Atlantic (24–26); these recur irregularly on the order of ca. 10,000 years apart and are typically followed by the warmest D/O interstadials.
Both Heinrich and D/O events exhibit clear global impacts. These patterns have been summarized in several studies [e.g., (26, 34)]. Although the pattern of influence appears to differ between these types of anomaly, a clear interpretation of these differences, particularly in terms of distinguishing physical mechanisms, has not been developed. As Hemming (26) notes, different global patterns of impact may simply reflect proxy-specific or site-specific limitations such as sensitivity and response time. In general, however, a cold North Atlantic corresponds with a colder, drier Europe, weaker Asian summer monsoon, saltier northwestern tropical Pacific, drier northern South America, colder/wetter western North America, cooler eastern subtropical Pacific, and warmer South Atlantic and Antarctic. Table 1 summarizes the main impacts of a cold North Atlantic (stadial) on key regions and systems.

With all due respect, most of your LIS references are extremely old and do not adequately reflect the state of modern understanding of LIS dynamics and decay. In particular, nobody would challenge the opening of the St. Lawrence at the time of the Younger Dryas, that is well established by Champlain Sea acoustic soundings and proxy evidence. The questions rather are more focused on the precise discharge routes, magnitudes and timing through Western Ontario – Thunder Bay – Lake Nipigon region wherein the numerous geomophological anomalies lie. Also questions still remain on the Northwest discharge routes that can only be answered by meticulous isostatically adjusted and LIDAR enhanced analysis of the Herman era GLA strandlines back up through Manitoba and Saskatchewan, work that is still in progress. Your confidence is premature.

GuarionexSandoval says:
June 16, 2012 at 5:12 pm
Or that it was a high current Z-pinch aurora triggered by a coronal mass ejection resulting in severe atmospheric disturbances, not limited to fires on a global scale in the Northern Hemisphere, and a high enough influx of radiation to mortally wound large terrestrial mammals, at least in the northern latitudes.
The aurora is not a high current Z-pinch or electric discharge and the giant ‘breach’ in the geomagnetic field is just ordinary magnetic reconnection that actually goes on all the time, In plasma physics, electric currents are caused by stresses in the plasma and electric fields are caused by relative motion between the plasma and the magnetic field.
William says:
June 16, 2012 at 7:55 pm
The Younger Dryas is a Heinrich event. I have looked at cause of the Heinrich in detail. They are caused by a pseudo cyclic interruption to the solar magnetic cycle.
There has never been an ‘interruption’ of the solar magnetic cycle [which is self-sustaining] and even if there were one, any effects would be extremely minor.

Gary Hladik

Well written article. Kept my interest to the very end.
While reading, I remembered that a repeat of the the supposed ocean circulation shutdown of the Younger Dryas was the premise of the comedy “The Day After Tomorrow”. As the prehistoric shutdown was the only semi-plausible scientific point in the movie, I’m saddened to see it questioned here. 🙂

LazyTeenager

However, according to many scientists there was an absence of meltwater entering world oceans approximately 13,000 BP, thereby making this scenario unlikely.
————
Well there must have been very large amounts of meltwater. It’s just uncertain whether there was a very sudden release and if there was was it enough to affect ocean circulation.
Apart from nits like this I found the article vet informative, though a but confused about cosmic events. Like was it an impact or was it some uptick in cosmic rays or what?

TRM

I fail to see why it has to be one or the other. The Earth is warming for thousands of years so those mile high ice packs on North America are building up large lakes of fresh water. Space debris impacts burst open the ice dams releasing a huge flood of fresh water into the Atlantic. The conveyor shuts down.
Nice idea but how do you find the impact zone? When the ice dam got hit it would all have melted away and been diluted and washed out to sea? Maybe some trace on the ocean floor of cosmic debris but it would be so diluted that it probably wouldn’t stand out.

RM says:
June 16, 2012 at 9:24 pm
Nice idea but how do you find the impact zone? When the ice dam got hit it would all have melted away and been diluted and washed out to sea? Maybe some trace on the ocean floor of cosmic debris but it would be so diluted that it probably wouldn’t stand out.

If it were an airburst over a substantial amount of ice, any cosmic debris would be carried away and scattered by meltwater.

John F. Hultquist

Others have questioned how a cosmic event could have such a long tail – 1,300 (?) years – or did something cosmic last that long?
The glacial fresh water flows don’t seem to be good candidates either unless there is some additional component not being investigated. Still some say the great ocean circulation has a transit time of about 1,600 years. Thus, a pulse, once started, might last a long time.
I don’t see in the paper any mention of the release of glacial lake water through the Mohawk River into the Hudson R. north of Albany. This is mentioned here . . .
http://en.wikipedia.org/wiki/Glacial_Lake_Iroquois
. . . with reference #3 being an investigation of this being a trigger for the Younger Dryas episode.
Abstract here:
http://www.mendeley.com/research/catastrophic-meltwater-discharge-down-the-hudson-valley-a-potential-trigger-for-the-intraallerd-cold-period/
. . . a short-lived (<400 yr) cold event (Intra-Allerod cold period) that began ca. 13,350 yr B.P.
{funny – only a geologist would think of 400 years as short-lived}

Don J. Easterbrook

This is a nice summary of PART of the YD story, but it lacks some of the most important aspects that relate to the glacial and ice core data. Perhaps a more accurate title might have been “The rest of part of the YD story.” The YD is a very important climatic event because it demonstrated that very abrupt, intense climatic changes could take place that are unrelated to Croll-Milankovitch slow orbital changes. It essentially spelled the death of the Croll-Milankovitch theory of the cause of Ice Ages. Attempts were made to save the theory by invoking the North Atlantic Deep Ocean Current changes that purported to explain such abrupt climate changes by turning the deep ocean current on and off with large influxes of fresh water from North America into the North Atlantic. However, this theory also fails because abrupt climate changes occur in both hemispheres simultaneously, whereas the Southern Hemisphere should lag the Northern Hemisphere by hundreds of years if the theory is valid. Some of the details of this may be found in http://myweb.wwu.edu/dbunny/pdfs/easterbrook_geologic-evidence-of-recurring-climatic-cycles.pdf
This part of the YD story is too long to detail here, but I’ll put a together a summary in the next couple of days. It’s an intriguing story.

Peter Lang

What is the policy impact of the Younger Dryas cooling event?
Given the Younger Dryas happened so suddenly and given that if something similar happened again the consequences would be extremely bad for mankind, it seems to me a good risk management strategy would be to get as much insulation around the planet as possible and get rid of those hazardous polar ice caps as quickly as possible.
Would a rational risk management approach be to burn more fossil fuels?

GeoLurking

Many times I have seen the impact idea for the Younger Dryas time period questioned due to the lack of an impact crater of the correct age.
A couple of items come to mind when I hear that;
Willamette Meteorite

There was no impact crater at the discovery site; researchers believe the meteorite landed in what is now Canada or Montana, and was transported as a glacial erratic to the Willamette Valley during the Missoula Floods at the end of the last Ice Age (~13,000 years ago)

http://en.wikipedia.org/wiki/Willamette_Meteorite
And there is also the Cape York meteorite(s)… also with no associated crater and of about the right age.
It would be interesting if they could nail the age estimates down to a higher resolution.
http://en.wikipedia.org/wiki/Cape_York_meteorite

Forget about the Atlantic. It is merely a longitudinal Tethys whose only claim to fame is its outlet for Arctic bottom water (which will continue to feed the THC regardless of surface salinity).
There are several well documented ice dam floods in the Columbia River basin that released enormous amounts of freshwater into the Pacific without noticeable effect.
THC bottom water is also formed in the Antarctic gyre.
The 14C excursion is interesting and news to me. I keep saying, despite the snickers, cosmic rays convert Nitrogen to 14C…

George E. Smith;

Well, I haven’t got around to reading it yet; looks like a chore; but looks like I do need to read it, so thanks for posting that encyclopedic Twoot about it.
“”””” BUT !!!!. the darn NCDC graphic, first pic is shrieking in my ear !!
What the hell is all that carry on at 1450 BP; Who Dat ? and howcum, nobody seems interested in what that is and what caused it. So what if that carry on at -1450 is actually cause and effect related to the YD 150 years later; that’s what I want to know ??
And I’m still waiting to hear who exactly, Younger and Dryas were.
But thanks for the keep awake tome.

QuantumPhysicistPhil

A solar magnetic excursion can only be assumed to have ‘minor’ effects on climate if we decouple that perturbation from the gravitationally-derived kinetic energy within the atmosphere. But that is a ridiculous thing to do and without going into details of why, it is this mistake that results in our incomplete understandings of tornadoes, the polar-annular modes, and the QBO, [to name a few examples]…we think we have the idea but thats because we parameterize. The Younger Dryas may or may not have featured cosmic involvement, but one things for sure..geomagnetic activity of some sort appears to have been the trigger. The answer lies in global circulation, it is quite unusual that we overlook the conteractive nature of the internally resonant behaviors in the north/south south annular modes (at time-specific intervals)…

tonyb

Very interesting. Much food for thought.Look forward to the follow up.
It is worth pointing out to regular readers of WUWT that the the Little Ice age -marked on the graph-is frequently msunderstood. Matthes, a glaciologist who coined the phrase as recently as 1939, meant it to refer to the last 4000 years or so, when there have been warm periods but essentially we are still in a little ice age compated to the previous few thousand years. He thought the present warm period-at the time of his writing-i.e the 1920’s and 1930’s, was merely yet another brief warm period between the main ice ages such as the younger dryas.
WE are in a relatively benign climatic period at present which is likely to turn out to be a relatively brief interval in the geological scale of events.
tonyb

I love the smell of science…
Thank you for a fascinating read.

Julian Braggins

Love mysteries, millions of recorded observations seems a good place to start such as the links provided by:
GuarionexSandoval says:
June 16, 2012 at 5:12 pm ~~~~~~
then the nano diamonds, anomalous beryllium, nitrates and ammonia plus widespread fauna and flora kill-offs, plus dramatic colder climate. I see where this is heading but am loath to mention close encounters of a celestial body on a science blog. 😉

I am pleased to see this saga continuing to unfold with general courtesy and general refrain from “Anthony! this is pseudoscientific drivel! it gives your work a bad name!” etc etc. Such measured response is AFAICT far more truly scientific 🙂
With that, a few things to mention:
(1) I’d like to endorse the book “Magnetic Reversals and Evolutionary Leaps: The True Origin of Species”, by Robert W. Felix. This book too is a good collection of a lot of evidence that has patterns that deserve looking at more closely. It is catastrophist. But without bad science or transcendental rants AFAICT. The only thing bordering “rant” is in the title: “true origin of species” but the book does contain significant evidence about the repopulation of species AFTER species-wiping-out catastrophic events. It may have faults. It may draw upon itself the wrath – and the measured criticisms – of the relevant orthodox gatekeepers – as does so much important ground-breaking material. It may not be “the answer”. But it has evidence well worth considering IMHO, and is a good read. I found it here, at WUWT, several years back. Thank you Anthony.
(2) remarks bordering on El. Universe material: I know this area is contentious here, liable to rouse endless bitching, and liable in consequence to very understandably rouse Anthony’s ire. But I personally also think it is rather crucial to understanding Younger Dryas. So – “handle with extreme care” and stay very brief, relevant, evidence-based, and scientific in attitude please, I don’t want to see the gradual unfolding of understanding stopped by a few selfish bitchers on all sides.
(3) even more, please hold back on “atlan..s” material. Email me privately on this one, if you believe you have significant relevant evidence Please keep it out of this thread.
Thank you Anthony a million for allowing these sometimes-difficult-to-handle frontier discussions. It’s an essential part of the reason I keep returning to this blog – taken together with the rest. And I am sure this is true for many others too.

Stephen Richards

Nice piece of work and a lot of effort to tell us where we are on the Younger-Dryas cooling. Very informative.

Jasper Solomon

If you want a good and exciting read (not peer-reviewed) of evidence for the cosmic event, try “The Cycle of Cosmic Catastrophes – Flood, Fire and Famine in the History of Civilisation” by Richard Firestone, Allen West and Simon Warwick-Smith (ISBN-13: 978-1-59143-061-2 and ISBN-10: 1-59143-061-5) published in 2006 by Bear & Company.