Study: Early humans witnessed global cooling, warming, and massive fires from comet debris impacts

From the UNIVERSITY OF KANSAS and the “humans have survived far worse climates” department.

Graph of temperature for the last 20,000 years, provided to illustrate this story, but was not part of the original press release.

New research suggests toward end of Ice Age, human beings witnessed fires larger than dinosaur killers

LAWRENCE — On a ho-hum day some 12,800 years ago, the Earth had emerged from another ice age. Things were warming up, and the glaciers had retreated.

Out of nowhere, the sky was lit with fireballs. This was followed by shock waves.

Fires rushed across the landscape, and dust clogged the sky, cutting off the sunlight. As the climate rapidly cooled, plants died, food sources were snuffed out, and the glaciers advanced again. Ocean currents shifted, setting the climate into a colder, almost “ice age” state that lasted an additional thousand years.

Finally, the climate began to warm again, and people again emerged into a world with fewer large animals and a human culture in North America that left behind completely different kinds of spear points.

This is the story supported by a massive study of geochemical and isotopic markers just published in the Journal of Geology.

The results are so massive that the study had to be split into two papers.

“Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Cosmic Impact ~12,800 Years Ago” is divided into “Part I: Ice Cores and Glaciers” and “Part 2: Lake, Marine, and Terrestrial Sediments.”

The paper’s 24 authors include KU Emeritus Professor of Physics & Astronomy Adrian Melott and Professor Brian Thomas, a 2005 doctoral graduate from KU, now at Washburn University.

“The work includes measurements made at more than 170 different sites across the world,” Melott said.

The solid line defines the current known limits of the Younger Dryas Boundary field of cosmic-impact proxies, spanning 50 million square kilometers. Again, used to illustrate this story, not part of the original press release.

The KU researcher and his colleagues believe the data suggests the disaster was touched off when Earth collided with fragments of a disintegrating comet that was roughly 62 miles in diameter — the remnants of which persist within our solar system to this day.

“The hypothesis is that a large comet fragmented and the chunks impacted the Earth, causing this disaster,” said Melott. “A number of different chemical signatures — carbon dioxide, nitrate, ammonia and others — all seem to indicate that an astonishing 10 percent of the Earth’s land surface, or about 10 million square kilometers, was consumed by fires.”

According to Melott, analysis of pollen suggests pine forests were probably burned off to be replaced by poplar, which is a species that colonizes cleared areas.

Indeed, the authors posit the cosmic impact could have touched off the Younger Dryas cool episode, biomass burning, late Pleistocene extinctions of larger species and “human cultural shifts and population declines.”

“Computations suggest that the impact would have depleted the ozone layer, causing increases in skin cancer and other negative health effects,” Melott said. “The impact hypothesis is still a hypothesis, but this study provides a massive amount of evidence, which we argue can only be all explained by a major cosmic impact.”


The study:

Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ∼12,800 Years Ago. 1. Ice Cores and Glaciers

The Younger Dryas boundary (YDB) cosmic-impact hypothesis is based on considerable evidence that Earth collided with fragments of a disintegrating ≥100-km-diameter comet, the remnants of which persist within the inner solar system ∼12,800 y later. Evidence suggests that the YDB cosmic impact triggered an “impact winter” and the subsequent Younger Dryas (YD) climate episode, biomass burning, late Pleistocene megafaunal extinctions, and human cultural shifts and population declines. The cosmic impact deposited anomalously high concentrations of platinum over much of the Northern Hemisphere, as recorded at 26 YDB sites at the YD onset, including the Greenland Ice Sheet Project 2 ice core, in which platinum deposition spans ∼21 y (∼12,836–12,815 cal BP). The YD onset also exhibits increased dust concentrations, synchronous with the onset of a remarkably high peak in ammonium, a biomass-burning aerosol. In four ice-core sequences from Greenland, Antarctica, and Russia, similar anomalous peaks in other combustion aerosols occur, including nitrate, oxalate, acetate, and formate, reflecting one of the largest biomass-burning episodes in more than 120,000 y. In support of widespread wildfires, the perturbations in CO2 records from Taylor Glacier, Antarctica, suggest that biomass burning at the YD onset may have consumed ∼10 million km2, or ∼9% of Earth’s terrestrial biomass. The ice record is consistent with YDB impact theory that extensive impact-related biomass burning triggered the abrupt onset of an impact winter, which led, through climatic feedbacks, to the anomalous YD climate episode.

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February 2, 2018 3:06 pm

Graham Hancock, call your office.

M Courtney
Reply to  tsenf
February 2, 2018 3:44 pm

More like call the appropriately named Firestone.
See here, for example.

Mike McMillan
Reply to  M Courtney
February 3, 2018 1:59 pm

I see Goodyear is a co-author in the Firestone paper.
The paper mentions the Carolina Bays elliptical lakes, probable impact sites. Down in Bolivia, up and down the river passing Trinidad (14°50’S 64°55’W), there is a 300 mile stretch of elliptical lakes, all with the same orientation, and another batch around (13°55’S 67°00’W) similarly oriented.
I haven’t found these site dated or mentioned as impact sites, but they might be from the same breakup.

Mike McMillan
Reply to  M Courtney
February 3, 2018 2:04 pm

Except Carolina Bays have a different orientation from the Bolivia sites. Their longitudes are close, however.

Reply to  tsenf
February 3, 2018 1:40 pm

Michael Mann, can you check this out with your hokey schtick???

Ken Mitchell
February 2, 2018 3:18 pm

Nothing really NEW here; for 4 or 5 years now, some scientists have been speculating for a bolide impacr in northern Canada as a cause for the Younger Dryas ice age. Lots more detail about the fires, and the spread, and it provides some suggestion about the extent of the devastation.
Also nice that this came from my alma mater, the University of Kansas.
But simple biology tells us that SOMETHING devastating affected the North American continent, and not all that long ago. Look at the apex predators here, and elsewhere.
In Africa and Asia, the most powerful predator is a cat; lions, tigers, panthers. Fast, sleek, efficient killers, but not all that rugged.
In North America, it’s the bear. A bear is more an all-purpose beast; not as fast, but more sturdy, and better able to withstand bad/cold conditions.

Extreme Hiatus
Reply to  Ken Mitchell
February 2, 2018 3:37 pm

Bears are omnivores. Except for polar bears which live in habitats where there minimal plant foods, bears are primarily vegetarian (depending on what is available in their particular habitat) and some populations are almost entirely vegetarian. Even the famous salmon-eating bears of the North Pacific coast get most of their nutrition from plants and get fat primarily from eating berries.
Salmon stop feeding and use their fat reserves to power their upstream runs to their spawning grounds. So the bears feeding close to where they start – like the famous Alaska bears – can get a lot of fat from them. But the further upstream you go the less fat they have. Similarly, seals are fat so that works for polar bears. This is critical because the key to bear survival and reproduction is getting as fat as possible each year for ‘hibernation’ and fatter females have more and stronger cubs.
Also worth noting that there are lots of bears in Asia, including the same species – brown bear – as the grizzly or Alaska brown bear.
The other big thing that happened in North America was the arrival of human hunter-gatherers.

Reply to  Extreme Hiatus
February 2, 2018 4:11 pm

“The other big thing that happened in North America was the arrival of human hunter-gatherers.”
Agreed. Certainly agreed.
However, it might be relevant – I think it is – to note that the existing fauna had not seen/experienced/been hunted by humans.
[Minor exception for any species that migrated across Beringia with Homo sapiens; perhaps Arctodus and Canis, which latter may have been commensal]
In Africa and much of Eurasia, the fauna had [horrible phrase] co-evolved with H. sapiens over – perhaps – several hundred thousand years: see, for example –
So – not necessarily naive.
Fauna that has not experienced humans is naive.
It is possible to approach very closely – Jared Diamonds’ writings, various, suggest this.
And others’ too, I expect.
Effectively, the humans who entered North America – perhaps 15,000 or so [I am not necessarily spot-on-accurate] – came with already-developed big game hunter technology – spears, atlatls, bows and arrows, concealed pits, stockading, driven hunts (using fire, very likely).
If the fauna – including the mega-fauna – was indeed naive, a very short sharp extinction is certainly possible.
Was there some stress from climate [the Younger Dryas, say]? Certainly.
But naive vulnerable fauna, impacted by a completely new technology [to them], would have certainly been at major risk to a population that knew no better.

Extreme Hiatus
Reply to  Extreme Hiatus
February 2, 2018 6:23 pm

Auto – Agree +100. Didn’t get into it further so glad you did.
Along with the hunting methods, weapons and fire, they also had DOGS. That is almost always overlooked but was a huge advantage in hunting many species as well as protecting their camps at night. For one major example, hunting bears is easy with dogs, and so is protecting your camp at night.
The other factor that is often ignored about hunting megafauna like mammoths is the modern concept of a quick sportsman-like kill. As the Bushmen of Africa demonstrated, that is irrelevant. All you need to do is fatally wound them. If it takes a week for them to die all that meat is still worth the effort of following their tracks, and it is much safer to patiently wait than rush in and try to finish them off.
The indigenous people of North America when Columbus arrived – at least those who lived as hunter-gatherers and hunted a lot, versus the farmers – used all these same methods and more. Thus the whole idea of the pre-European ‘pristine wilderness full of abundant wildlife’ is a complete myth. But the Green Blob keeps pushing it because it is supposed to make everything now seem so much worse… and it is all our fault of course.
Here’s a great book the Greenies successfully buried that you can read on line:

Reply to  Extreme Hiatus
February 2, 2018 10:48 pm

If people are giving something away for free, why do they insist on knowing your email address?
A couple of weeks ago I bought an item of furniture using a version of my name to perform the transaction that is ‘what is on the bank card’
yesterday an entirely unrelated (I thought) company selling furniture spammed me..
Sorry, but I won’t be downloading that e-book or reading online

Roger Knights
Reply to  Extreme Hiatus
February 2, 2018 11:24 pm

One other hunting technique overlooked is stone-throwing. Humans (males, anyway) can accurately throw medium-weight sharp-edged stones medium distances. No other primate can. A flurry of these from a hunting party (perhaps concealed by a waterhole or game trail) would wound a prey animal to some degree. Then human’s superlative stamina in long-distance running would enable the weakened prey to be chased until exhausted.
(There is a scientific paper detailing this, and a popularization of it in a magazine article that I have, but it’s buried in my files.)

Extreme Hiatus
Reply to  Extreme Hiatus
February 2, 2018 11:43 pm

“Sorry, but I won’t be downloading that e-book or reading online.”
Leo – Sorry about that. I have never actually tried. I have a hard copy of that book and when trying to provide a link to it, that was the only one I could find. As I mentioned, they have successfully buried that book.
There are copies out there, and the details are real eye openers, but the summary they show at that link describes the basic (though understated) idea:
Wilderness and Political Ecology
“Description : Environmental law and philosophy assume the existence of a fundamental state of nature: Before the arrival of Columbus, the Americas were a wilderness untouched by human hand, teeming with wildlife and almost void of native peoples. In Wilderness and Political Ecology Charles Kay and Randy Simmons state that this “natural” view of pre-European America is scientifically unsupportable. This volume brings together scholars from a variety of fields as they seek to demonstrate that native people were originally more numerous than once thought and that they were not conservationists in the current sense of the term. Rather, native peoples took an active part in managing their surroundings and wrought changes so extensive that the anthropogenic environment has long been viewed as the natural state of the American ecosystem.”
Googling should find some great papers by the lead authors, particularly Charles Kay. His main one is tilted
‘Aboriginal Overkill…”

Bob Burban
Reply to  Extreme Hiatus
February 3, 2018 10:37 am

Leo Smith : “If people are giving something away for free, why do they insist on knowing your email address?”
If you buy something, it is a product. If you are offered something free, you are the product …

Reply to  Extreme Hiatus
February 4, 2018 8:53 am

Auto said (and Extreme Hiatus agreed) – February 2, 2018 at 4:11 pm

[Quoting Extreme Hiatus] “The other big thing that happened in North America was the arrival of human hunter-gatherers.

Agreed. Certainly agreed.
However, it might be relevant – I think it is – to note that the existing fauna had not seen/experienced/been hunted by humans.
[Minor exception for any species that migrated across Beringia with Homo sapiens;

Being the per se, “resident contrarian”, I’se just hasta say:
That long-touted “Beringia migration” being responsible for Homo sapiens populating of the Americas ……. is an interesting and colorful “story” created out of thin air and vivid imaginations, but is not based in actual facts or evidence, …… only assumptions, guesses and “blue sky” dreams.
Factual evidence (Clovis “flint” projectile points) proves that the “Clovis Culture” inhabited North America during the Younger Dryas Period between 13,000 BP and 12,600 BP. Therefore, the Clovis people had to have been in North America long before that 13K BP date in order to invent/create the Clovis Point shape and get it accepted throughout their widely dispersed populations residing all across North America. To wit:
Anyway, those long-touted “Beringia migration” claims have been proven “null and void” via this recent discovery, to wit:

Ancient baby DNA discovered in Montana yields new clues to earliest Americans
The DNA of a baby boy who was buried in Montana 12,600 years ago has been recovered, and it provides new indications of the ancient roots of today’s American Indians and other native peoples of the Americas.
…… (Sam C, says: Human migrations across Beringa during the height of the last glacial maximum, is one (1) thing, …….. whereas trekking Eastward across the tops of the Rocky Mountains to what is now the State of Montana, ……. during the height of the last glacial maximum would have been damn near impossible to achieve.)
It’s the oldest genome ever recovered from the New World. Artifacts found with the body show the boy was part of the Clovis culture, which existed in North America from about 13,000 years ago to about 12,600 years ago and is named for an archaeological site near Clovis, N.M.
The boy’s genome showed his people were direct ancestors of many of today’s native peoples in the Americas, researchers said. He was more closely related to those in Central and South America than to those in Canada. The reason for that difference isn’t clear, scientists said

Reply to  Samuel C Cogar
February 4, 2018 9:15 am

But how long did it take for “one tribe” to cross America?
Lewis and Clark needed only five years to cross the US from their homes in the outback to Washington DC to Pittsburgh PA to St Louis MO to Mandam-Bismark ND to Portland OR to St Louis MO and back to Washington DC. Boats going down river, horses. Roads had been cut – but only in some places.
Julius Caesar? Egypt, Gaul, Rome, North Africa, and Europe. In one lifetime.
The Greeks? Macedonia to Egypt to India via Persia, Turkey. In less than two lifetimes.
The Huns, Vandals, Magyars, Vikings, Goths, Visigoths, Franks? Only 200-300 years from the Roman Empire’s control of all of Europe, MidEast and Africa to a stage where all of those tribes re-conquored all of North Europe through Italy and Spain and North Africa.
The Mongols? Mongolia to Vienna – In one lifetime.
True, you cannot equate a “tribe” moving “naturally” cross-country with a group of men ordered to cross by their supervisors, but – still – all of those groups and armies and tribes and their “civilization” and tools and influence still moved tens of thousands of miles cross-continents in mere years.
Trade and commerce may be even more effective a guage of contact: The smallpox virus credibly “traveled” by simple person-to-person contact from the Mexico City Indian tribes back to the Hudson Bay tribes in Canada across the inhospitable Great Plains of in less than 3 centuries.

Sir Padre
Reply to  Extreme Hiatus
February 4, 2018 9:57 am

There Ain’t No Such Thing As A Free Lunch

Extreme Hiatus
Reply to  Extreme Hiatus
February 4, 2018 6:21 pm

Samuel C Cogar – Thanks or your comment. But what Auto mentioned (and I agreed with) regarding Berengia was this:
“Minor exception for any species that migrated across Beringia with Homo sapiens”
That was it as far as any discussion of the pathways of colonization was concerned. The evidence shows multiple pathways. There is evidence of earlier human movement down the Pacific Coast. There is also evidence of (later) use of the ice-free corridor from Berengia. So your critique was of a point that neither of us suggested.
The Monte Verde site pretty much ended the ‘one migration via Berengia’ theory long ago, although it was strongly opposed by supporters of that theory (as usual with new theories). Here’s the (simplified and sanitized) version from Wiki:
“Monte Verde is an archaeological site in southern Chile, located near Puerto Montt, Southern Chile, which has been dated to as early as 18,500 BP (16,500 B.C.).[1] Until recently, the widely published date has been 14,800 years BP.[2] This dating added to the evidence showing that the human settlement of the Americas pre-dates the Clovis culture by roughly 1000 years. This contradicts the previously accepted “Clovis first” model which holds that settlement of the Americas began after 13,500 BP. The Monte Verde findings were initially dismissed by most of the scientific community, but in recent years the evidence has become more accepted in some archaeological circles,[2][3] There is as yet no consensus, and vocal “Clovis First” advocates remain.[4]”
Because of the remarkable similarity to “Clovis” artifacts I also find this to be intriguing (again from wiki; short on time right now):
“The Solutrean hypothesis about the settlement of the Americas claims that people from Europe may have been among the earliest settlers of the Americas.”
All I think we know for sure now is that this story is far more complicated than the original ‘Clovis First, ice-free corridor’ story, that it happened earlier than first thought, and that it did in fact happen.

Extreme Hiatus
Reply to  Extreme Hiatus
February 4, 2018 6:36 pm

RACookPE1978 – You wrote:
“Trade and commerce may be even more effective a guage of contact: The smallpox virus credibly “traveled” by simple person-to-person contact from the Mexico City Indian tribes back to the Hudson Bay tribes in Canada across the inhospitable Great Plains of in less than 3 centuries.”
There were vast trade networks. Inter-tribal contacts undoubtedly played a major role in spreading smallpox.
But the first major epidemic that began in Mexico in the 1500s did not just impact “tribes”; rather it impacted an Empire that was not much different than some earlier European empires. That is the main reason why the Spanish conquests were so fast and relatively easy.
Also, while it is uncertain just how far that first mega-epidemic spread, there were subsequent reintroductions and epidemics that were responsible for the ones that reached Hudson’s Bay.
It is also worth noting that the Hudson’s Bay Company started innoculating the tribes who traded with them during the 1775-82 mega-epidemic so they were less impacted than others. In western Canada, unlike the US, the indigenous people were partners in the fur trade and were vital to its success.

Dallas Patterson
Reply to  Extreme Hiatus
February 6, 2018 1:52 am

The arrival of human species in the Americas is still an unfolding debate and object of research. There is now a 2017 report where researchers describe what they believe was a Mastodon kill in the San Diego, California area by a band of humans…130,000 years ago! This is believed to long pre-date the emigration of Homo sapiens out of Africa to the rest of the World. There are other hotly debated research findings in South America dated to more than 30,000 years ago. Presumably the postulated cosmic impacts described in this article may have been responsible for a near extinction or extinction of the earliest human inhabitants of the Americas. Unmentioned is the contributions to great biomass fires and faunal extinctions made by the super-volcanic eruptions of the Hot Spot in North America (Nevada, Utah, Colorado, Wyoming, Idaho) and present day Yellowstone Hot Spot. These super-volcanic eruptions periodically blanketed much of the present day United States between the Sierra Nevada Mountain Range, Cascade Mountain Range, and the Mississippi River with volcanic lava and ash often tens of meters to hundreds of meters deep in lava and ash while burning tens of thousands of square kilometers more of forests and grasslands. Makes you wonder whether or not any early humans will be discovered to have been buried in the ash fall of those eruptions.

Reply to  Extreme Hiatus
February 6, 2018 4:24 am

@ Extreme Hiatus – February 4, 2018 at 6:21 pm

Samuel C Cogar – Thanks or your comment. But what Auto mentioned (and I agreed with) regarding Berengia was this:
“Minor exception for any species that migrated across Beringia with Homo sapiens”
That was it as far as any discussion of the pathways of colonization was concerned.

EH, my post in question was predicated on this portion of Auto’s post, to wit:

Auto- February 2, 2018 at 4:11 pm
Effectively, the humans who entered North America – perhaps 15,000 or so [I am not necessarily spot-on-accurate] – came with already-developed big game hunter technology – spears, atlatls, bows and arrows, concealed pits, stockading, driven hunts (using fire, very likely).
If the fauna – including the mega-fauna – was indeed naïve, a very short sharp extinction is certainly possible.

Now, EH, I have to assume that in the above, Auto was referring to a calendar date of 15,000 BP for a Bering Sea “ice bridge” crossing into NA…… and NOT an immigrant count of 15,000 humans crossing said “ice bridge” into NA.
And EH, please note this excerpt from your Wikii quote, to wit:

This dating added to the evidence showing that the human settlement of the Americas pre-dates the Clovis culture by roughly 1000 years. This contradicts the previously accepted “Clovis first” model which holds that settlement of the Americas began after 13,500 BP.

EH, common sense and logical deductions should enlighten most any sensible person to the FACT that the Clovis (people) culture DID NOT immigrate into NA from some far distant land.
The “Clovis culture” were descendants of the original immigrants from south Asia into western South America ……. or more likely (according to the Clovis site map), the descendants of the original immigrants from southern Europe into eastern North America, ….. like the Cherokee Indians of the Carolinas. Where ever they originated from, their particular “napping technique” did not become “common practice” until several thousands of years AFTER their ancestors arrived in the Americas.
And there is this:

New Evidence Puts Man In North America 50,000 Years Ago
Date: November 18, 2004

Radiocarbon tests of carbonized plant remains where artifacts were unearthed last May along the Savannah River in Allendale County by University of South Carolina archaeologist Dr. Albert Goodyear indicate that the sediments containing these artifacts are at least 50,000 years old, meaning that humans inhabited North American long before the last ice age.
“Topper is the oldest radiocarbon dated site in North America,” Goodyear says. “However, other early sites in Brazil and Chile, as well as a site in Oklahoma also suggest that humans were in the Western Hemisphere as early as 30,000 years ago to perhaps 60,000.”

And Extreme Hiatus, ……. the Great Pyramid of Giza, the Sphynx, and the stone work at 2 or 3 archeological sites in South America are “proof-positive” factual evidence that present day researchers really don’t have a clue as to how long ago BP that intelligent beings were constructing “things” out of stone on the earth’s surface.

Reply to  Extreme Hiatus
February 6, 2018 4:50 am

@ Dallas Patterson – February 6, 2018 at 1:52 am

The arrival of human species in the Americas is still an unfolding debate and object of research. There is now a 2017 report where researchers describe what they believe was a Mastodon kill in the San Diego, California area by a band of humans…130,000 years ago! This is believed to long pre-date the emigration of Homo sapiens out of Africa to the rest of the World.

Dallas Pattrtson, …… you tell um, …… I type slow.
“DUH”, the ……. “down out of the trees, ….. n’ across the HOT savannahs ….. and then Out of Africa” theory of Homo sapien sapien evolution …. is a “junk science” fairy tale that rivals that of Santa Claus and the Easter Bunny.

Reply to  Ken Mitchell
February 3, 2018 7:21 am

A bear is also an omnivore, not totally dependent on large ungulates as a prime food source.

Steve O
Reply to  Ken Mitchell
February 9, 2018 9:40 am

It’s not just four or five years ago that speculations arose. This all sounds A LOT like what Immanuel Velikovsky wrote about a half century ago. He wrote a series of three books.

Eric Stevens
Reply to  Steve O
February 9, 2018 1:26 pm

It doesn’t sound at all like Immanuel Velikovsky other than it involves astronomical bodies colliding with each other. Velikovsky didn’t make much sense even when he wrote his stuff. It makes even less sense now. I suspect the impact theory currently is at the same stage as continental drift in 1910. Lots of it is wrong but parts of it are close to the truth.

February 2, 2018 3:18 pm

People just don’t recognise when they are well off and dream of going back to some Mythical state in which pure bliss is reached by all. Et in Arcadia, Ego!

Lance Wallace
February 2, 2018 3:21 pm

“Graph of temperature for the last 20,000 years, provided to illustrate this story, but was not part of the original press release.”
No source mentioned? The graph appears to show the Little Ice Age occurring more than 1000 years ago.

Janet L Chennault
Reply to  Lance Wallace
February 2, 2018 4:19 pm

Yes, please tell source of graph – and the key to the numbers thereon.

Reply to  Lance Wallace
February 2, 2018 5:15 pm

The last 1000 to 1200 years does not match up with what I have seen from lots of other sources.

Reply to  Lance Wallace
February 2, 2018 5:16 pm

The peak identified as the Midieval Warm Period is more likely the Roman Warm Period, The MWP is probably the next peak. I don’t see any Little Ice Age on that chart, unless it’s that tiny little dip about 200 years before present.

Wayne Townsend
Reply to  MarkW
February 2, 2018 5:20 pm

the whole decline with the blip below the line is the LIA

Reply to  MarkW
February 2, 2018 10:50 pm

I agree. The trough 1000 years ago was the late dark age cold period

Sir Padre
Reply to  MarkW
February 4, 2018 10:20 am

Didn’t see the Minoan Warming Period either.

Reply to  Lance Wallace
February 2, 2018 7:17 pm

Don’t you recognize GISP2? It is not global temperature. It is Central Greenland temperature.

Extreme Hiatus
February 2, 2018 3:22 pm

“According to Melott, analysis of pollen suggests pine forests were probably burned off to be replaced by poplar, which is a species that colonizes cleared areas.”
This is odd because most pine species are well adapted to frequent fires and some, like lodgepole pines, are fire dependent over the long term. Their cones pop open when they are burned thus producing their characteristic even-aged stands.
If these stands are not burned they eventually get killed off by mountain pine beetles – which was recently blamed on The Warming when it was really Smoky the Bear’s fault. Fire suppression also explains the big Yellowstone fires (mostly lodgepole pine) as well as the ‘extreme’ fires in California which are always blamed on The Warming.
True that deciduous trees like aspens and ‘poplars’ also pop up after fires but this still does not make sense to me. If there were pines there before the fires there should have been pines growing back immediately after them.
On the bright side, that graph will make Mann’s head explode.

Extreme Hiatus
Reply to  Extreme Hiatus
February 2, 2018 3:24 pm

Forgot to add that after mountain pine beetles kill off mature stands that leaves a ton of dead wood waiting to burn, which pops open the cones and reseeds the area with pine, again.

Reply to  Extreme Hiatus
February 3, 2018 8:57 am

Extreme Hiatus, the proposed fire wasn’t your typical event — this was God’s flaming breath from the heavens. Prb’ly hot enough to kill all the pine-seeds. Poplars have very feathery, wind-blown seeds and could recolonize much quicker starting from the edges of the destruction.

Reply to  beng135
February 5, 2018 11:29 pm

Poplars such as Aspen mostly propagate through clones. Underground roots send shoots up which are clones of the parent and very large stands of Aspen are the result. No seeds required.

Reply to  Extreme Hiatus
February 4, 2018 9:44 am

Extreme Hiatus – February 2, 2018 at 3:22 pm

True that deciduous trees like aspens and ‘poplars’ also pop up after fires but this still does not make sense to me. If there were pines there before the fires there should have been pines growing back immediately after them.

EH, it is entirely dependent upon “fire intensity”, that is, if it was a “normal” quick-burning forest fire, a “ground” fire, a “crown” fire or a “total destruction” inferno fire.
Pine tree “growth” will survive the first three (3) “fire types” ….. but not the 4th type.
A quick-burning forest fire will save some pine trees and/or pine cones (seeds) on the ground for re-seeding or re-population.
A “ground” fire will only partially destroy pine seeds and/or pine seedling on the ground.
A “crown” fire will likely kill the pine trees …. but will cause the pine cones to “open up” and disperse their seeds to insure “new growth” via re-seeding or re-population.
Whereas a “total destruction” inferno fire will destroy (consume) all living and dead biomass it encounters.

Extreme Hiatus
Reply to  Samuel C Cogar
February 4, 2018 5:57 pm

Thanks beng135 and Samuel. That does make sense to me, particularly given that poplars “could recolonize much quicker starting from the edges of the destruction.”

Reply to  Samuel C Cogar
February 5, 2018 4:20 am

Extreme Hiatus, the seeds of both the Tulip poplars and the Maple trees can be transported quite a distance across “burnt” ground if the wind is strong enough.
And the “nuts” of various trees such as the hickories, walnuts, chestnuts, acorns, hazelnuts, etc., can be carried quite a distance from the source tree(s), by animals, with many of those seeds being buried in the soil for safe keeping, to be eaten later. Many of those buried seeds could probably survive an “inferno” type burn and would likely “sprout” soon after the rains returned. And last but not least, birds can transport “seeds” over great distances to effectively aid in the re-population of burnt areas.

Zurab Abayev
February 2, 2018 3:23 pm

This site in the past published the study which proved bolid impact as WRONG>>>

February 2, 2018 3:26 pm

Any mention in the papers of the Carolina Bays?

Wayne Townsend
Reply to  Theyouk
February 2, 2018 5:19 pm

Yes, it is a regular feature of this debate in the 2007, 2011 and 2018 papers.

February 2, 2018 3:26 pm

Alas, pay-walled. Would really like to read this, might have to pay the $10.

Reply to  pameladragon
February 3, 2018 9:55 pm
February 2, 2018 3:30 pm

DNA evidence indicates that there were three times when the human population was reduced so much that it could easily have gone extinct. link On the other hand, our intelligence could be due to the fact that we were tested hard and had to evolve real fast.

The ones that did survive got both lucky and smart. They were lucky because many of them happened to settle beside the sea in what’s now South Africa. Their particular spot of ground happened to be rich in plants that stored their energy in starchy tubers below the surface the soil. The water beside their area was warmish, and nourished a supply of shellfish. Between the two, humans managed to gather enough food to get by. They helped themselves along, though. A cave called PP13B, near Pinnacle Point in South Africa, shows evidence that the people there used the shellfish shells as tools. It’s also possible that they heated and tempered their stone tools, making them more behaviorally modern than people 150,000 years ago generally get credit for being.

Reply to  commieBob
February 2, 2018 4:18 pm

It may be that species that require a lot of post natal education have a survival advantage over species with innate (instinctive) prenatal programming. It might be nice to know how to eat and walk mere seconds upon dropping from the womb, but it comes with a price: you know almost everything you’ll ever know at birth, and can’t learn much if anything more. Humans are born with very few instincts and require many years of education before they are ready to leave the nest. As such our education may be adjusted to suit the current needs. As the habitat changes so may our education… not so much for the mastadons. We’re clever creatures that have so far proven difficult to eradicate.

Pop Piasa
Reply to  rocketscientist
February 2, 2018 5:30 pm

The only glitch has been that humans seem to want to eradicate other humans who are not in their clan.

Reply to  rocketscientist
February 2, 2018 10:53 pm

The only glitch has been that humans seem to want to eradicate other humans who are not in their clan.

Only when there is competition over land and food resources. Think of it as evolution in action.
I wonder whether homosexuality is a response to high population density as well.

Reply to  rocketscientist
February 3, 2018 6:42 am

Humans are not the only animals that fight over territory. Even to the point of death.

Reply to  rocketscientist
February 4, 2018 10:02 am

rocketscientist – February 2, 2018 at 4:18 pm

It may be that species that require a lot of post natal education have a survival advantage over species with innate (instinctive) prenatal programming.

“HA”, there are several species of Cockroaches that will surely disagree with your above assessment.

Dan Harrison
Reply to  commieBob
February 2, 2018 5:17 pm

Many years ago, circa about 2002, I read a research report that may take the above one step further. For the human animal to evolve big brains a certain type of fat is needed: the same fat found in shellfish.

Pop Piasa
Reply to  Dan Harrison
February 2, 2018 5:22 pm

You mean shellfish people are fat? (nyuk, nyuk)

Pop Piasa
Reply to  Dan Harrison
February 2, 2018 5:24 pm

Oops, I meant “fat headed”. Freudian slip.

Pop Piasa
Reply to  Dan Harrison
February 2, 2018 5:27 pm

Blew my own punch line… Drat.

Reply to  Dan Harrison
February 3, 2018 9:08 am

Pop Piasa, that means smart people know when to clam-up.

John Harmsworth
Reply to  Dan Harrison
February 3, 2018 9:10 am

Climate scientists must be really smart! Michael Mann’s head looks like it’s ALL fat!

Reply to  commieBob
February 3, 2018 3:33 am

How the devil do you “heat and temper a STONE tool”

Reply to  Andrew
February 3, 2018 6:44 am

You put it into a flame. I’ve read that tempering obsidian makes it less brittle.

Crispin in Waterloo but really in Beijing
Reply to  Andrew
February 3, 2018 8:27 am

Tempering is a stress-relieving process. Heating a flint tool changes the crystal structure, lustre and colour. It was known for a long time, of course, that heating a wooden weapon hardened it. It is torrefied by heating it to 290 C which removes moisture, and makes it unlikely to absorb moisture. The difference between a ‘piece of wood’ and a hardened tip is significant.

Steve Keohane
Reply to  Andrew
February 4, 2018 6:06 am

Prior to knapping, stones were often placed to line a firepit to treat them for more controllable working of the stone. After having played with this manufacturing process to the extent of making fine points and knife blades, I’m surprised they weren’t all blinded by the flakes from the stones, lacking safety glasses.

Crispin in Waterloo but really in Beijing
Reply to  commieBob
February 3, 2018 3:38 am

There is a cave on the west side of the Lubombo (also ‘Lebombo’) mountain south of Swaziland with evidence of occupation 120,000 years ago. Not near the sea, but great hunting below on the lowveld floor.
The most interesting thing is they were not San or Khoi both of whom arrived there much later. It was a while ago, but a blood type investigation showed the San are from Western Asia – out of Africa and back again. I’d like to hear if there are genetic studies confirming this.
The ‘strandlopers’ (beach runners) encountered by Diaz on the South Coast in the 15th century were using Dravidian words and not looking San at all. Out of India!
Amazing world we have.

John Harmsworth
Reply to  Crispin in Waterloo but really in Beijing
February 3, 2018 9:24 am

I had understood that the San/ and Khoi possess the “most primitive” human genome. 5he least adjusted by subsequent regional changes.
If that is true then it would mean that Asians evolved from Africans, which I understand the Chinese don’t quite accept in the same way. Apparently they think they may have evolved separately and more directly from Erectus. Clearly nonsenseI think but more interesting to me are the high cheek bones and narrow eyes of the bush people. They have fairly Oriental features to my eye.

J Mac
February 2, 2018 3:33 pm

This is very interesting! Is there a non-subscription, ‘free’ source for the full report?

Reply to  J Mac
February 3, 2018 9:54 pm

Yes, posted at my blog here:

ian whittaker
February 2, 2018 3:35 pm

I would take this report with a considerable grain of salt. Have a look at the author list on both papers. Then have a read of this:
Also, for a more formal repudiation:
The Younger Dryas impact hypothesis: A requiem
Pinter, N. et al.
That isn’t to say that they haven’t genuinely found something new in these latest papers, but I would await some analysis by others before taking it as read.

Wayne Townsend
Reply to  ian whittaker
February 2, 2018 5:17 pm

So, we have good scientific back and forth 2007 paper pro impact, 2011 refutation, 2018 reply to refutation. Science in action. Gotta love it.

Eric Stevens
Reply to  ian whittaker
February 3, 2018 12:50 am

You seem to be evaluating the message on the basis of the messenger. That’s not very scientific.

ian whittaker
Reply to  Eric Stevens
February 3, 2018 7:08 am

No, I evaluate it on how poor the previous ‘findings’ were. Believing that micrometeorites can penetrate chert, or mammoth tusks, at half rat power is not very good science. Mistaking arthropod poop for spherules is not very good science. Claiming finds to support your view that turn out to be only 200 years old is not good science. Having a convicted felon, with no scientific qualifications, as the corresponding author is not very confidence building.

February 2, 2018 3:50 pm

Wow sounds like Immanuel Velikovsky.
In spite of his meticulous research and writing, he was similarly discredited by the 1950′ academia and beliefs of the time.
He was refused publication in academic journals by academics, many of whom had not even studied his papers.
In the end he published his research as books which are very good reading and all have extensive bibliography.
Strangely enough, since the comet Shoemaker–Levy 9 collided with Jupiter, academia has been sitting up and reviewing Velikovsky’s writings.
He even writes about how the mastodons suddenly became frozen in Siberia with food in their stomachs that has never grown locally.
It is easy to relate this with the way may academics treat global warming. They seek to shut the door and abuse anyone who contradicts them in a very similar treatment that Velikovsky got.

Reply to  rogerthesurf
February 3, 2018 6:47 am

The notions pushed by Velikovsky are ridiculous.
If a comet were to hit the earth hard enough to shift the axis of rotation, it would have completely shattered the earth.

Reply to  MarkW
February 3, 2018 1:04 pm

Try actually reading his books yourself and don’t forget to check the bibliographies.

Steve O
Reply to  rogerthesurf
February 9, 2018 9:49 am

I had exactly the same thought.

Ted Clayton
Reply to  rogerthesurf
February 9, 2018 12:48 pm

It is not necessary to ‘closely’ read Velikovsky’s “Worlds In Collision”, to know whether it is valid. Scientific theories or scholastic arguments are subject to the old maxim that any chain is no stronger than its weakest link. That’s why the Ape-Human intermediary is a proper noun: Missing Link. Without all the links, we can have speculation of varying intuitive/inductive believability … but to make it deductive Science, we need links solidly connected in an unbroken chain.
Objectively, by argumentation, there is very little to compare, between Worlds In Collision and the Younger Dryas Impact Hypothesis. They’re very different cases. However, they do share the weakness of having key broken links in their evidence chain.
You don’t have to read Velikovsky, because his command of Celestial Mechanics is about what we’d expect, from an old-school Psychiatrist & Psychoanalyst. No self-respecting Pulp SciFi Hack would be caught dead making the hash of orbital physics that Classics-scholar Velikovsky casually commits to the printed page.
The YD Impact was at one time a promising hypothesis – and far more popular & exciting than today – but that was when the Carolina Bays could still be cited as a vast field of impact-features. Once it became clear that the Bays are not impact-scars, the YDB-event went back on the always-long Intriguing-but-Unsupported idea-list.
A closer comparison for the Sky-on-Fire Mammoth Killer, might be Elon Musk’s Mars Colony. Can this happen, something-like he says? Are all the links in this proposal in-place & hooked securely together? Maybe … but some of his key assumptions might be Carolina Bays.

Reply to  Ted Clayton
February 11, 2018 11:19 pm

Well Ted, I do not mind comments that disagree after looking at the evidence, in this case Velikovsky’s writings, therefore I can only say that you are taking a risk by criticism without actually reading what he says.

February 2, 2018 3:55 pm

Check out Immanuel Velikovsky . He researched all this in the 1950’s Provided a lot of solutions to perplexing evidence that we are increasingly finding nowadays:)

ian whittaker
Reply to  rogerthesurf
February 3, 2018 6:59 am

The reason that Velikovsky was ignored/ criticised was because he was an out-and-out woo merchant. He got nothing right, and completely disregarded the laws of physics. His re-dating of Egyptian pharaohs, to fit in with biblical woo was wrong, and has been proven to be so by 14C dating. In short, his contribution was worthless, and remains so.

Reply to  ian whittaker
February 3, 2018 9:01 pm

No, carbon dating proves him correct.

February 2, 2018 3:55 pm

Sorry. This BS Younger Dryas theory has been disproven several times in several papers, in several different ways. Anyone who has read the literature would be able to call immediate BS on the ‘new’ evidence based on the old.

ian whittaker
Reply to  ristvan
February 2, 2018 4:08 pm

Yep, the micrometeorites in mammoth tusks was somewhat embarrassing!

Reply to  ristvan
February 3, 2018 10:01 pm

Fake news, dude. The supporting independent verifications out weigh the critical papers. See Table A3 of Supporting Information of Paper #1 here:

Eric Stevens
February 2, 2018 3:57 pm

There have been hints of such an event, indeed a series of events, reported over the last forty years. The first may have been the book “The Cosmic Serpent” by Victor Clube and Bill Napier .
The topic was expanded in “Natural Catastrophes During Bronze Age Civilisations” [BAR International Series 728] edited by among others Benny J Peiser, now of the GWPF.
More recently there have been the contentious and disputed theories of Richard Firestone .
… and now this.
Clube and Napier postulate that the earth was subject to a series of bombardments, almost up into historical times and it is probable that many eschatological stories now regarded as myth are founded on the description of actual events.

ian whittaker
Reply to  Eric Stevens
February 2, 2018 4:11 pm

“… and now this.”
Sorry, but this is Firestone again. He’s on the author list for both papers. Ergo, best to treat it as nonsense, unless somebody else replicates the findings. It didn’t go well last time.

Eric Stevens
Reply to  ian whittaker
February 9, 2018 1:32 pm

If they are going to replicate his findings, this time they will have to look exactly where he said to look. He made much of what he found in the immediate vicinity of the ‘black layer’ but his critics seem to have looked further afield. No wonder they never found what Firestone reported.

February 2, 2018 4:09 pm

The abstract reads like a novel, all precipitated on the arrival of a comet.
No chance that lightning strikes could have ignited the biomass ?
What’s to say that the earth didn’t just pass thru a dense cloud of the fabled “dark matter” ?

Steve Fraser
Reply to  u.k.(us)
February 2, 2018 9:37 pm

Source of the platinum deposits, esp in the Greenland ice, would need attribution.

Reply to  u.k.(us)
February 3, 2018 2:35 am

-all predicated-

Reply to  Abiogenesis
February 4, 2018 12:52 pm

Thanks for the correction.
I’ll try to be more careful in the future.

February 2, 2018 4:42 pm

Is it only gaseous extractions from ice core samples that are questionable?

Wayne Townsend
February 2, 2018 4:53 pm

I may be mistaken, but I believe the illustration at the top is mis-marked. “9” points to the Roman Warm Period, “10” would be the “dark age” cold period. If they were moved over one set of peaks to the right, they would be correct.

Reply to  Wayne Townsend
February 2, 2018 5:20 pm

The text at the bottom of the graph indicates that it was added to illustrate the story, but wasn’t part of the original press release.

Wayne Townsend
Reply to  MarkW
February 3, 2018 1:53 am

Your reply does not seem to address my comment.

Bob Burban
February 2, 2018 4:57 pm

An interesting work on human experiences with comets: “The Cosmic Serpent” by Victor Clube and Bill Napier.

Bill Illis
February 2, 2018 4:58 pm

A 100 km wide comet, would have extinguished all life on the planet. The crust would have melted out down to 20 kms or so. We probably have never been hit by an object that big and moving that fast in 4.3 billion years, Maybe some 20 km objects hit us up to the late heavy bombardment which ended 3.9 billion years but certainly not a 100 km comet after 4.3 billion.
And If a 100 km-wide comet disintegrated along the Earth’s orbit so that we got hit by some of it, we would still be running into it every several years or centuries and the 1 km chunks left over would be impacting us at some point. Nope. Didn’t happen and not happening.

Reply to  Bill Illis
February 2, 2018 5:22 pm

Assuming the Earth as a globe of Jell-O, how long before the shock waves (of a major hit) quiet ?
How about a second hit, during that time ?
Are we still resonating from eons ago ?

Reply to  Bill Illis
February 2, 2018 5:23 pm

That seems to be one of the weakest portions of this paper.
According to the above story, the earth wasn’t hit by a 100km comet, but rather a 100km comet broke up and pieces of it hit the earth. They seem to be suggesting a number of impacts over the northern hemisphere.
They specifically claim that other pieces of the comet are still out there.
Exactly how they determine the size of the pre-breakup comet would be interesting to see.

Dan Harrison
Reply to  Bill Illis
February 2, 2018 5:28 pm

Remember Comet Shoemaker–Levy 9? About 40 or so years ago I read a chapter in a geology text devoted to evidence of a large comet strike that ended the last ice Age. But it wasn’t just one strike. There was comet debris in a 5,000 year orbit that the Earth passed through every 5,000 years–the same 5,000 year cycle found in the Maya calendar. I’ve always wondered if Shoemaker-Levy was the remnant of this comet just a few years earlier than the Maya calendar predicted due to orbital perturbations. We were lucky Jupiter got in the way of the 24 largest impacts.

Bob Burban
Reply to  Dan Harrison
February 3, 2018 2:20 pm

Dan Harrison “Remember Comet Shoemaker–Levy 9?” The pattern of a series of fragments striking a rotating sphere could be likened to the effect of machine-gun bullets hitting a giant rotating ball. Why are kimberlites (originating from a depth of ~600 km) found sometimes distributed along a more-or-less straight line?

Reply to  Bill Illis
February 2, 2018 5:28 pm

I’m wondering how they figure the comet was 100 km in diameter, and how they know that fragments of the comet still exist.
I believe they said just fragments of the comet struck Earth, but I still wonder how they know the fragments came from a comet 100 km in diameter.

Dan Harrison
Reply to  TA
February 2, 2018 5:48 pm

Years ago Sandia National Laboratories in Albuquerque, NM computed both the size and the shape of the Tunguska event that occurred in Russia in 1908 using a super computer. But the above is different. I’ve previously seen weak estimates compiled by adding fragments and associated debris. Several periodic meteor showers have been the subject of such calculations.

Reply to  TA
February 3, 2018 6:49 am

You could calculate the size and mass of all the fragments that hit the earth, but how do you do that for the fragments that didn’t?

Reply to  TA
February 3, 2018 2:05 pm

Size of the comet – Taurus Complex progenitor – was first figured by Sir Fred Hoyle, who started summing the remaining mass of objects in the several streams of the Taurus Complex. He also added zodiacal light, scattered ice grains that are not primordial, which he believed was recently injected into solar orbit.
Theory is that sometime in the last 20 – 50k years a large comet entered the inner solar system, was perturbed into an earth crossing orbit and somewhere along the line (before, during or after) disintegrated. There are at least 19 currently known asteroids and at least one active comet (Encke) that have similar orbital elements. Collectively all this garbage is referred to as the Taurus Complex. Last year, another branch of the Taurid Complex was discovered. The Tunguska object is thought to have been a Taurus Complex object.
Earth may or may not cross more dense portions of the streams every 1,500 or 3,000 years. We cross portions of the two main streams twice a year. Some of the investigators are trying to tie impact events to the fall of ancient civilizations. They are getting pretty good support from tree ring guys like Mike Baillie. The ancients were absolutely freaked out about comets. If the YD guys are right, they had a good reason, which is why we keep looking.
Note that we see fragmenting / dissolving comets all the time. To have a pair of debris clouds working the solar system at the same time (Kreutz Group and Taurus Complex) tells me that they are not all that uncommon. One source for these appears to be the Centaurs, which are large objects in unstable orbits between Saturn and Uranus. They are in turn fed by either the Kuiper Belt or the Oort Cloud. When something leaves the Centaurs, they either come in or are ejected. Most recent of these I could find was Hale – Bopp.
This is new, new, new, and has not been disproven at all, though the notion of catastrophic encounters with comets makes a lot of people uncomfortable. OTOH, it has not yet been proven either, and is still in the arm waving and chair throwing stage. I think there is enough there to keep on looking. Your mileage may vary. Cheers –

Don K
Reply to  Bill Illis
February 2, 2018 7:30 pm

Bill, I think the scenario they have in mind is more like a big mass of frozen gases and maybe some rocks swings into the inner solar system, crosses the Earth’s orbit and breaks up when the gases binding it together start to evaporate. The pieces travel together through perihelion — presumably outgassing like mad — and start back out to whence they came. Except their crossing of the Earth’s orbit coincides with the Earth’s passing through and vacuuming up a lot of the pieces. The rest of the object — what’s left of it — travels off toward the outer solar system. Presumably the debris cloud comes back every X thousand years — more diffuse with every revolution around the sun.
Could that happen? Maybe? Did it happen? Ask again in a century or so.
Caveat: I am in no way, shape or form, an astrophysicist — just a computer guy who mis-spent part of his youth supporting satellite projects.

Reply to  Don K
February 3, 2018 2:26 am

Don K
I think you’ve got it about right. I was going to do one of my long explanations re comet break-up, return frequency (orbit size, shape, period) and would’ve added a few things in but your summary is a good one.
Just one point though. Comets can fragment due to spin-up via torquing due to asymmetrical outgassing. This is especially likely at low perihelion values. The typical spreading-apart velocities of escaping fragments are around 1-2 metres/sec while some may not escape and remain in a ~50km radius (100km diameter orbit). I wonder if this is what is meant by “100 km wide”. If a solid 100 km comet went to low perihelion it would be very unlikely to fragment due to higher mass and consequent escape velocity (and orbit velocities) and also a higher mass/surface area ratio meaning higher coefficient of inertia and way more outgassing torque required over a period of only a month or two.

Reply to  Don K
February 3, 2018 2:50 am

On re-reading the abstract it does say a 100km comet. It’s much harder for this to fragment unless suffering a collision…but collisions are thought (modelled) to be so rare that any purported collision would likely have been millions of years before the impact event. In that time, the fragments disperse into a very wide meteor shower- a tube, several million km wide which the Earth ‘cores through’ over several days. So possibly the 100km diameter is the minimum size required to provide a debris field that’s dense enough to supply multiple impacts over that 2 or 3 day coring event. This sounds vaguely plausible though the Earth is a very small target for such a spread of fragments that are not dust and tennis-ball sized. They’re deemed to be big and threatening even if there’s dust in there with them too.
This is no different from the Earth ‘coring’ through the Geminids and Perseids for a couple of days every year except those streams don’t contain loads of giant fragments (as far as we know…)

Don K
Reply to  Don K
February 3, 2018 4:39 am

Your comments sound fine to me, to the very limited extent that I’m qualified to understand the situation. I agree that we must be dealing with a debris field, not a solid object. And my impression is that it’s pretty hard to get a comet to break up. I was thinking that a close approach to the sun might cause breakup from differential heating. But rotational torque sounds fine to me.
One thing though. The Earth’s velocity is roughly 30km/sec. That suggests to me that it’d whip through a 100km wide debris field in about 3 seconds.

Reply to  Don K
February 3, 2018 6:52 am

Presumably, the debris field would be substantially larger than the original comet.

Reply to  Don K
February 3, 2018 12:40 pm

Don K (& Mark W)
I think my second comment above is more accurate so I think they mean a highly dispersed fragment cloud (as Mark W suggests) and possibly millions of km across- all from a 100km-plus comet.
However, the following might be useful for visualising either single fragments from the cloud hitting every few hours as we fly through the ‘tube’ (see my above comment)…or, to visualise the more compact, 100km-wide cloud hitting all at once.
This tweet useful for general picturing of how asteroids (and comets) approach the Earth.
As you can see, the decider as to whether the rock will hit or not is where along its orbit it is. In this specific case of ‘asteroid 2017 PDC’ it was a fictitious asteroid that was used for an emergency response exercise at the Planetary Defence Conference in 2017 in Tokyo.
Whether or not 2017 PDC hit depended on whether its actual position on the predicted day of arrival was along a particular length or section of its orbit. That section corresponded to the diameter of the Earth plus a few thousand km either side corresponding to the max altitude at which the Earth’s gravity can bend a rock in when flying past at ~13km/sec (13km/sec was 2017 PDC’s radiant speed which is the vector sum of the two orbital speeds at the orbit crossover angle).
So 2017 PDC could be anywhere along a particular stretch of its orbit that corresponded to a length of 12,740km (Earth diameter) plus about 4000km either side = 20,740 km. And that stretch of its orbit had to be where the Earth’s orbit crosses its orbit. All very precise and coincidental which is why these big impacts are so rare.
You can see how the probability line of all the possible modelled candidates (red line) approaches the Earth sideways at the 13km/sec radiant speed, like a traffic stream of cars changing lane on a freeway- they appear to move sideways as they travel almost parallel along the freeway with the Earth. But unlike the freeway, they just carry on and crash into us sideways.
There was only one possible position for 2017PDC within all these candidate red dots but if it had fragmented into a 100km wide cloud of bits, it would be a small disc somewhere along the red line. And that disc could be anywhere along the ~20,000km sweet spot if on course for an impact.
When the red candidate line sweeps past the Earth, the 20,000km line gets spliced out of the longer probability line and wraps around more than half the planet due to gravitational lensing of the outermost candidates. The rest miss the Earth and stay in orbit around the sun (the nearest ones somewhat perturbed to new orbits).

Reply to  Don K
February 3, 2018 12:48 pm

…PS: in the tweet pics above, the date for 2017PDC’s orbital speed has the correct impact month and day but says “2017”. It should be “2027”, the day of the (fictitious exercise) impact.

Reply to  Don K
February 3, 2018 2:40 pm

“the scenario they have in mind is more like a big mass of frozen gases and maybe some rocks ”
A 50- to 100-kilometer diameter scoop of vanilla ice cream, crusted with a shell of cooled hot chocolate fudge, embedded with crushed nuts?

Reply to  Bill Illis
February 2, 2018 11:00 pm

I dont think that follows. Comets do not go ‘along the earth’s orbit’ they are in extremely elliptical orbits and would be perturbed by a close pass with the earth into orbits that might never again cross the earth’s orbit at all.
Every case in recent times of Tunguska like events has not shown any repetition.
I would say its entirely possible that a close pass by a ‘dirty snowball’ with the earth would result in breakup, some bits landing and some bits flying off into outer space.
That’s not to say that I believe the thesis: Just that your refutation is not based on what I understand to be the behaviour of comets.

Eric Stevens
Reply to  Bill Illis
February 3, 2018 12:53 am

I believe it is postulated as a 100 km wide shot gun blast, not a 100 km wide cannon ball.

February 2, 2018 7:00 pm

“On a ho-hum day some 12,800 years ago, the Earth had emerged from another ice age.”
Wednesday, wasn’t it?

February 2, 2018 7:01 pm

Amateur here, but I always understood the Younger Dryas to be the result of ice melt cooling the oceans and subsequent effects. That still an operative theory?

Reply to  michaellbromley
February 2, 2018 7:19 pm

The Greenland ice cores show there were about 20 such events during the last ice age. It’s probably more related to sea level and how the Gulf Stream organized and then reorganized itself as sea level rose and fell.
When sea level fell, the Gulf Stream could not flow into the Gulf of Mexico and around Florida. It went a outside the Carribean islands in these times. When the tipping points got reached, it took more than a century for the Gulf Stream to reorganize and flow far enough north to warm up the North Atlantic. 5 degrees latitude of flow pressure was all it took to cause these 20 or so rapid warming and then cooling events.
Fresh water melting off of the glaciers on land would not change salinity enough to cause these changes so that explanation is just Fake news.
If a comet caused these changes, it happened 20 different times in the last 120,000 years. The impact theory people never talk about the other 19 times the same situation occurred. Each time, species were at risk and many went extinct at event 12 and event 18 but the impact guys never talk about these extinctions.

Reply to  Bill Illis
February 2, 2018 7:22 pm

Ok, thanks for explanation: if it wasn’t fresh water melt, then what caused the sea level fluctuations?

Reply to  Bill Illis
February 2, 2018 7:29 pm

Okay, good point. Yes it was the melting/glacial build-up that caused the sea level changes. Which came first then, The chicken or the egg. 20 different times.

Reply to  Bill Illis
February 3, 2018 6:53 am

It’s been shown that the Gulf Stream only has a small impact on the temperature of the European continent.

February 2, 2018 7:24 pm

I’ve long thought the Younger Dryas was caused by an incoming grenade. It nicely explains the northern Siberian flash frozen mammoths.

February 2, 2018 7:47 pm

That Allen West, a convicted felon who changed his name and has no known scientific training, is the author for correspondence, raises serious doubts about the study. Doubts that do not decrease when one sees:
RECEIVED: Sept 11, 2017
ACCEPTED: Sept 14, 2017
Woah, a three day peer-review. Or perhaps the Journal of Geology is not a peer-reviewed journal.
Too sad seeing that Paul Mayewski is part of this.
Plenty of hypotheses about the cause for the Younger Dryas, but little convincing evidence for any of them.
I remain skeptical, and of this work very skeptical.

Reply to  Javier
February 3, 2018 10:15 pm

Convicted felon? You lying &(^%. Allen West is friend of mine and he had a minor license violation consulting briefly on CA job (guild central) as an Arizona license hydrologist. His enemies, and the enemies of peer-reviewed science, like Dr. Mark Boslough, have smeared him with this foolish — expunged — charge for years. I explained it here in 2011: Crawl back under your log you anti-science cheap shot artist. Allen West could run circles around everyone on this board.

Reply to  George Howard
February 4, 2018 1:50 am

The charge was not spunged. He pleaded guilty. Hard to say that his enemies made him plead guilty.
That you are his friend only tells your bias.

February 2, 2018 9:18 pm

Bill Illis is right – the Bolling-Alerod warm peak 14000 years ago followed by the Younger Dryas cooling was just another Dansgaard-Oesger (DA) event of which there were 20 in the last glacial period. It was ocean-driven – AMOC turning off and on again, there is a replete literature on the subject. Plus as Bill points out, the size of the proposed object is fantastical. Sell.

February 2, 2018 9:42 pm

I see quite a mass of strong assertions that this is phooey, but little specific critique of why.
I would pay good money to see the commenters on this site engage with Randall Carlson regarding the data surrounding the theories about YDB anomalies. I’d wager the man has spent far more time reading through the scientific literature combined with a more macro based view of reality than what I’ve seen from the rigid status quo-sticians here. Further, his quality of debate and professionalism isn’t lost on folks like me appreciate healthy argumentation. Please, someone reach out to him and set up an interview and let’s beat to death all the studies, arguments, counter arguments, etc… And see where the logic takes us.
Granted, I’ve learned much because of the contributions of the commenters (and I’m grateful) however I also routinely see valid counter points never countered, which always leaves me disappointed. I’m itching to see a panel of genuine debate about many of these unknowns

Reply to  honestliberty
February 2, 2018 11:05 pm

I suspect in this case as in ‘climate change’ everyone is looking for the One True Cause whereas in fact it may be that frighteningly familiar thing in so many disasters, a chain of coincidences. Of which cometary impact may well be one
This is the horse and the hound and the horn
That belonged to the farmer sowing his corn
That kept the rooster that crowed in the morn
That woke the judge all shaven and shorn
That married the man all tattered and torn
That kissed the maiden all forlorn
That milked the cow with the crumpled horn
That tossed the dog that worried the cat
That killed the rat that ate the malt
That lay in the house that Jack built.
More wisdom in that nursery rhyme than the whole IPCC.

Reply to  honestliberty
February 3, 2018 12:12 am

Here is the oceanographic explanation of the series of events leading to the termination of the last glacial period, namely the Bolling-Allerod, the Younger Dryas and Holocene inception. Bolide impacts might have happened around that time but are not needed to explain these events.

The Bolling-Allerod (Northern hemisphere warming at 14,600 yrs ago) and Younger Dryas (subsequent 1000 yr cold interval) were features of the last deglaciation driven by oceanographic processes. The deglaciation starting as early as 22yrs ago led by warming in Antarctica. The general picture is one of steady changes in Antarctica contrasting with unstable fluctuations in the NH driven by the Atlantic Meridional Overturning Circulation (AMOC).
The root cause of this NH fluctuation is an instability in the AMOC arising from a positive feedback which it possesses. Cold water formation and downwelling in the Norwegian sea drives the gulf stream – reactive flow of Carribean warm and – critically – saline water across the Atlantic to north west Europe. This gulf stream water has high salinity, and this makes the cold water formed in the Norwegian sea even more dense than would result from its temperature alone. So this cold and saline water sinks all the way to the Atlantic floor and is one of the principal drivers of the global thermo haline circulation (THC). This “deep water formation” at the Norwegian sea in turn speeds up the gulf stream – something has to replace all that sinking cold super-salty water. Thus the positive feedback.
Where you have a positive feedback in an open dissipative far-from-equilibrium system you have the conditions for nonlinear oscillation. This is directly analogous to the ENSO in the Pacific, the positive feedback of the Bjerknes mechanism (cold upwelling strengthens trade winds strengthening cold upwelling etc.) giving rise to the ENSO nonlinear oscillator, although the AMOC operates over much longer – century and millenial – timescales than ENSO (year to decadal).

So a basic oceanographic feature comparing the NH with the SH in the palaeo record is more fluctuation and instability in the NH and more stable, gradual changes in the SH. The nonlinear instability of the AMOC is the root of this. Also, there is a clear signature of interhemispheric bipolar seesawing, whereby when the NH moves in one direction, the SH moves in another. This is not universal however – sometimes at the moments of biggest transition, NH and SH move together.

About 22 kYa (thousand years ago) Antarctica started warming. The slow oceanic warming caused by peaking obliquity was hoovered to Antarctica by deep ocean circulation. The NH at the same time slightly cooled.
However at about 14 kYa the “Bolling-Allerod” (BA) happened, i.e. the NH abruptly warmed, as evidenced by Greenland cores. This was accompanied by a reciprocal pause and slight reversal in the (already long established) gradual Antarctic warming – the bipolar seesaw again. This episode is referred to as the “Antarctic cold reversal”.
At the time of the BA there was a sharp rise in global sea level – 20 meters in 500 years. Weaver et al 2003 (link below) show that this was caused by a collapse of the gradually warming Antarctic ice sheet. The resulting pulse of fresh meltwater from Antarctica had the long range effect of speeding up the AMOC and the gulf stream in the NH, bringing rapid warming to the NH and the BA.

The bipolar seesaw continued – as the NH became sharply warmer, there followed in the SH the Antarctic cold reversal where temperatures went slightly into decline.
However down in the deep ocean, ongoing century-scale interactions between the SH and NH caused – about a thousand years later – an abrupt stoppage of the AMOC and the gulf stream. In fact the cuplrit was Antarctic Intermediate water (AAIW) – see again Weaver et al. With the interruption of the gulf stream the NH went cold again – the Younger Dryas. In response – by now you get the picture – the Antarctic returned to gradual warming.
Eventually, after about 1000 years of NH cold with no gulf stream (the YD) the after-effects of the huge Antarctic ice sheet collapse finally subsided allowing the AMOC and the gulf stream to resume. Now followed an exception to the bipolar seesaw – both NH and SH warmed together, around 12 kYa. This marked the final end of the last glacial and the Beginning of the Holocene.

Wayne Townsend
Reply to  ptolemy2
February 3, 2018 2:12 am

There are eternally questions in this topic, like: “So what caused the end of the NH/SH see-saw, or is it still a feature of life — such as the cooling in Antarctica which counters NH warming presently?”

Reply to  ptolemy2
February 3, 2018 3:38 am

“Heat piracy” is the reason for the NH-SH bipolar seesaw. There is so much heat energy in the ocean and it takes so long to change this amount (e.g. 6500 year lag between obliquity and interglacial timing) that in the “short” term of decades to centuries, ocean heat is a bit of a zero sum game. If ocean currents steal heat from one hemisphere to the other, then one gets warmer and the other colder. The best thing about this “heat piracy” is that it tends to happen around the Caribbean.

Reply to  ptolemy2
February 4, 2018 5:37 pm

I’ll get to digest that in time. How would a massive impact on the north american icesheet impact that change?
Massive flooding would make its way to the ocean, the heat impact would burn much around that wasn’t under ice. Have I missed something?
Look, my point was I would like someone of your learned caliber to actually discuss this in a podcast or interview that lasts three hours so the combination of views gets sorted out, piece by piece, and the viewer (layperson such as myself) doesn’t have to spend months researching something I’d rather not. SO, would you be willing to do it and bring up all your points to someone like Randall Carlson to refute and respond or do you just want to come here and claim ownership of knowledge of the past as fact to someone of little knowledge such as myself? Randall, I can promise you is no mental slouch and additionally, if you proved him wrong is the type of man strong enough to admit it.

ian whittaker
Reply to  honestliberty
February 3, 2018 7:29 am

Sorry, but that isn’t how it works. This is science, not an Oxford Union debate, or the Jerry Springer show. The hypothesis, if such it is, is dismissed because the evidence isn’t what it is claimed to be, has been misinterpreted and/ or simply doesn’t exist. Their 2007 paper was drivel. No other word for it. I have posted the link before to the paper that trashes these findings. That is what you should be reading; not looking for TV or radio debates:

Honest Liberty
Reply to  ian whittaker
February 4, 2018 5:42 pm

how interstering you are willing to dismiss something so accessible as to point people such as myself in the right direction after tuning in to something like a 3 hour debate. I don’t need you to tell me what I should do, so keep your status quo suggestions to yourself. It is an adjacent ad hominem, insinuating that I’m not intelligent enough to pierce through the BS. I haven’t seen an actual live debate between the two sides rather than post rebutes after the fact. Nor did I find the avenues of “scholarly” research to vet the questions.
MY POINT, was for people like me who have little knowledge, a nice debate that lasts a few hours would be a great primer to get me on the right track. Your dismissive attitude is exactly what is wrong with status quo religionists like Michael Shermer, who someone pointed out as some sort of legitimate “skeptic”. Right.
He’s an apologist for the state, big pharma, and everything status quo. He is about as credible of a source as Karl Marx.

Ted Clayton
Reply to  honestliberty
February 4, 2018 6:48 pm

honestliberty says:
“I see quite a mass of strong assertions that this is phooey, but little specific critique of why.”
The base-critique is: the Impact Hypothesis originated as an interpretation of the Carolina Bays ‘pock-marks’, as the impact-signatures of a ‘shotgun-blast’ disintegrating comet.
But then, it turned out the Bays are not impact-features at all.
Yet, the exciting comet-idea remained popular … even without its primary evidence. So supporters went looking for other ways to argue that there really was a big astronomical impact.
It’s really quite difficult to prove that an impact occurred. Even with a gaping crater staring us in the face, that is often the only evidence we have that anything happened. If Tunguska had not had eye-witnesses, and National Geographic photographed the blast blowdown, there would be no hint that it happened.
Even the Chicxulub ‘Dinosaur Killer’, with many decades of research, remains a matter of several controversies.
It became a very steep uphill intellectual struggle to sustain the Younger Dryas Impact Hypothesis, once the tangible evidence in the form of the Carolina Bays was invalidated.

Reply to  Ted Clayton
February 4, 2018 8:32 pm

Thank you for a succinct and polite response. Does the claim that the supposed multiple impacts hit the ice sheet a cop out or does it warrant a reasonable explanation to the evidence of massive flooding in the northwestern United States and black mat later find in the ydb impact boundary? Is it not possible that it could have happened and been a catalyst to global climate change with all that excess water immediately changing the temperature and salinity on a mass scale? If not, why is this so difficult to believe?
To clarify, I don’t know enough. I truly don’t and my hope is to get those who have the years of research condense it into something I can approach without spending years reading the literature. I have other interests. Making whiskey is something that I focus most if my free time on, just ahead of CAGW nonsense.
I perceive Randall Carlson as an intelligent scholar who has put in the time and challenges the modern interpretation of the past. I know this: his redemption of the beast article really helped build my knowledge base about the glory of CO2 and the silliness of the CAGW movement.
He is not a uniformitarianist and that makes sense to me.
He is will articulated, patient, and has tons of field experience. I consider him someone of significant credibility. I think he would agree with most of not all of the commenters on here.
However, regarding the Carolina bays, I’ve not heard that specifically. I’ve only tuned in the least few years. My reference was toward an extra terrestrial impact on the North American ice sheet and the northern Pacific ocean, approximately 4 separate impacts during the younger dryas.
Pardon the length of my response. My method of learning is one that I can listen to solid debate for hours, and then research the points to gather how often each side was accurate. I need that and this is why I made my suggestion.

Ted Clayton
Reply to  Ted Clayton
February 5, 2018 6:46 am

[R]egarding the Carolina bays, I’ve not heard that specifically.

Carolina Bays are Saddam Hussein’s weapons of mass destruction. They’re the original & real reason for all this. Except, Hussein did not have WMD. And Carolina Bays are not impact-features. It’s unlikely that one could get on top of the Iraq-story, without getting on top of how WMD got it all going … and then turned out to be bogus.
These so-called Bays are a strange land-feature; lakes, ponds and depressions with a particular shape and orientation. They often have a slightly elevated bank or berm at the ‘far end’. Start with the Wikipedia links, then search & wander on the Web for racier & weirder coverage of them. It’s out there. Homework.
Understandably, people who embarrassed themselves with WMD-malarkey (or worse?) … and people who took the Bays to be evidence of a game-changing cosmic event (which turned out to be wrong) … are not keen to draw attention to their mistake.
Pres. George W. Bush, once it became undeniable that there were no WMD, ‘shifted’ the story. “Wull, wull – he’s a Bad Guy anyway! Go git him boys!” But wait a minute – the original & real reason for attacking Iraq (the proof that Hussein was a bad-guy), was the WMD … which – oops – didn’t exist.
Likewise, there were people who really & truly loved the Big Comet Strike scenario (and all the cool follow-on things that can be tied to it, like the Younger Dryas and mass-extinctions) … and when their only real & scientific support for a Big Important Impact turned out to have nothing to do with any kind of impact … they too ‘shifted’ the story.
That’s the real story here. A human story, not a science-story. An all-too-human story.

Ted Clayton
Reply to  Ted Clayton
February 5, 2018 9:38 am

Refs for Carolina Bays as the foundational Younger Dryas Impact Hypothesis evidence.
Here is the earliest publication of which I am casually aware, which accounts for the Carolina Bays as impact-features.
“The Carolina “Bays”: Are They Meteorite Scars?”
by F. A. Melton and William Schriever
The Journal of Geology 41, no. 1 (Jan. – Feb., 1933): 52-66

Aerial photographs of a district on the coastal plain of South Carolina reveal hitherto unknown relationships among surface depressions of a peculiar type, the origin of which has long been a subject of speculation. These relationships include (1) a smoothly elliptical shape, (2) parallel alignment in a southeastern direction, (3) a peculiar rim of soil which, with unimportant exceptions, is invariably larger at the southeastern end than elsewhere, and (4) mutual interference of outline. Consideration of all of these facts leads to the conclusion that the origin is not directly attributable to ordinary geologic processes. On the contrary, a hypothesis involving impact by a cluster of meteorites is presented as the most reasonable explanation. The supposed swarm must have been large enough to possess a cross-sectional area at right angles to the direction of movement of the order of magnitude of 50,000 square miles.

To extract, highlight & emphasize:
“[T]he origin of [Carolina Bays] has long been a subject of speculation [ca 1933] … a hypothesis involving impact by a cluster of meteorites is presented as the most reasonable explanation.” [emph. & annot. added]
I have not yet seen a freely-available full-text copy of this report. Just the Abstract, so far (at multiple URLs).
I am also including here a non-academic (but ‘serious’) article, from 1951, partly because it makes pointed reference to the above paper and its interpretations, importantly because it confirms ‘soft’ assertions that I have made elsewhere about the social context of the Bays & impact-scenario, and because it is fully available. I believe there are several other worthwhile papers pre-dating this one, and a string of others following it … all having been published & being well-known, during a period well-preceding what is nowadays typically posed as the beginning of the (YDB et al) ‘comet-idea’ (in the ’60s and ’70s).…..59..199K
“The origin of the Carolina Bays and the Oriented Lakes of Alaska”
by Kelly, A. O.
Popular Astronomy, Vol. 59, p.199

The origin of the Carolina Bays and the Oriented Lakes of Northern Alaska is a problem that has long intrigued the scientific world. Probably the great interest in the scientific puzzle arises from the fact that Melton and Schri[e]ver, geologists from the University of Oklahoma, who first discovered the Carolina Bays, attributed them to a gigantic shower of meteorites. This interpretation was made in 1933. Such a spectacular theory immediately aroused the interest of the Press and several articles appeared in popular magazines describing the fearful holocaust that must have occurred.

The modern context of proposed impacts to explain the Younger Dryas, attendant global climate change, mass extinctions and alterations of human prehistory, all trace directly to a period of intense fascination with a putative colossal astronomical strike (or sustain bombardment), beginning in the early 20th C, and based on an erroneous interpretation of the Carolina Bays as impact-features.

February 3, 2018 12:20 am

Here is another recent post at Judy Curry’s site about the effects of extreme climate change on recent human evolution and migration out of Africa – the great exodus 60,000 years ago:

February 3, 2018 12:50 am

The age of modern humans , or at least their residence outside Africa , may have been greatly increased by new discoveries in India : from Nature , just published :
-“Luminescence dating at the stratified prehistoric site of Attirampakkam, India, has shown that processes signifying the end of the Acheulian culture and the emergence of a Middle Palaeolithic culture occurred at 385 ± 64 thousand years ago (ka), much earlier than conventionally presumed for South Asia1. The Middle Palaeolithic continued at Attirampakkam until 172 ± 41 ka. Chronologies of Middle Palaeolithic technologies in regions distant from Africa and Europe are crucial for testing theories about the origins and early evolution of these cultures, and for understanding their association with modern humans or archaic hominins, their links with preceding Acheulian cultures and the spread of Levallois lithic technologies”-
Obviously this will have to be verified by further studies , but it just shows how the science is never settled , (except of course for climate science).

Reply to  mikewaite
February 3, 2018 3:10 am

Modern human remains predating the 60kya breakout are old news – ones in India, China and around Israel and the Levant have been in the literature for a decade. They are periodically re-reported as new findings, as now.
Indeed starting with the appearance of H sapiens about 200,000 years ago, there were periodic break-outs from Africa. The claims about the 60 kya breakout are not that this was the only breakout. This is a common misunderstanding or oversight. No – the claim – backed up by genetic evidence, is that it was this 60 kya breakout, the first to happen after humans became behaviourally modern about 70 kya, was the one to which nearly all humans outside Africa today trace their descent. This is shown for instance by the mitochondrial haplotype L3 labellling of this migrating group. Some groups exiting Africa left desendants. Others did not – or left only a small trace of their genes.
Just to be clear – the fact there were numerous “exodi” from Africa both before and after the 60 kya event, does not alter or contradict the clear evidence from genetics, from both maternal mitochondrial and male Y-chromosome analysis, that most humans today are indeed descended from that single 60 kya breakout. As Richard Dawkins showed mathematically in “The Ancestor’s Tale”, prior to 20,000 years ago, everyone alive was ancestor either to everyone living today, or to no-one.
Science writers and journalists are a lot to blame for this muddle and for inaccurate, biased and politicised reporting of scientific research in general including in climate science. When these media copy-writers try to dumb down a research publication for a press release, they use the report as a vehicle for all their own predjudices, policy agendas and pet ideas. So I have learned to ignore the pre-amble in media reports of scientific findings and just read the abstract directly, and if possible the paper also.
It has been known for years that H sapiens exited Africa as long ago as 200, 000 years, with the well known discoveries in India, China and the Levant (endlessly re-reported as new findings). We are told that this discovery at Misliya cave in Israel dated to 177,000-194,000 years ago, changes everything in human origin research. It changes nothing and is not even new. These reporters seem never to have heard of genetics.

February 3, 2018 1:08 am

This is all old news.
Here is a link to the 2015(?) Joe Rogan podcast with Randall Carlson and Graham Hancock in which they present very detailed and credible evidence for the meteor strike. However, since they are not “academics’, they were/are widely ridiculed.
However, now that an “academic” has come up with the very same theory, it is big news.

Reply to  William
February 3, 2018 11:24 am

They had a subsequent podcast with Rogan that also featured Michael Shermer. He questioned the validity of many of their conclusions (Hancock’s in particular) and it’s fair to say that the current evidence of an advanced civilisation at that time doesn’t meet the standard one would demand for a typical scientific hypothesis to be accepted as established. However, given the events proposed, could that ever be the case?
Hancock said himself that you can’t say that with certainty, but it’s definitely plausible, and more plausible than the Egyptologists’ established theory that the Sphinx enclosure was excavated 4500 years ago in a dry climate at a time that the Sphinx wasn’t facing Leo at sunrise.
Carlson’s evidence for an impact of enormous consequence at the time in qurstion is pretty solid. Together with Hancock’s work collating evidence from others in Egypt, Gobekli Tepe, India (where other ancient monuments align perfectly with the summer solstice 12,800 years ago) and South America, it is currently at least the most plausible hypothesis that this comet caused devastation worldwide, and that some humans at the time had reached levels of civilisation (settlement, agriculture, technology and astronomy) across the world well in advance of the hunter-gatherer level you’ll see presented in museums and textbooks.
The Plato/Atlantis thing is hugely interesting even if it does turn out to be a myth, but if a tiny morsel of the money given to climate science were directed to marine archeology, we could investigate around the Azores neighbourhood and find out whether the greatest legend in our history really was based on a genuine place.

honest liberty
Reply to  Keith
February 4, 2018 5:50 pm

Michael Shermer is unqualified to remark on much that he does, and evidence of that is littered throughout the webosphere with people calling out his monumental ignorance. Graham was absolutely validated with his attack on Shermer for publishing such a disingenuous hit piece… and to claim he didn’t know is even more disingenuous. He is nothing short of an apologist for the state, status quo, etc… He is NOT a skeptic. I don’t throw the word schill around often, but he meets all the criteria. The guy is classless and ignorant on much of what he claims to be skeptical.

February 3, 2018 2:05 am

(I would suggest that) the illustration published by WUWT in 2012comment image
identifies timing of the MWP and the LIA accurately.

Wayne Townsend
Reply to  vukcevic
February 3, 2018 2:12 am


February 3, 2018 5:47 am

All are other aspects of the Solutrean Hypothesis for the origin of pre-Clovis New World aborigines.

February 3, 2018 6:31 am

No one has mentioned the draining of Lake Agassiz as cause of the disruption of Arctic and north Atlantic currents in the time frame discussed.
I quote part of the Wiki article :
Lake Agassiz’s major drainage reorganization events were of such magnitudes that they had significant impact on climate, sea level and possibly early human civilization. Major freshwater release into the Arctic Ocean is considered to disrupt oceanic circulation and cause temporary cooling. The draining of 13,000 years ago may be the cause of the Younger Dryas stadial.[1][8][9] The draining at 9,900–10,000 years ago may be the cause of the 8,200 yr climate event.
Is this theory now discounted ? If so , on what evidence, because it does seem plausible.

Reply to  mikewaite
February 3, 2018 6:58 am

I thought lake Agassiz drained into the Pacific?

John Harmsworth
Reply to  MarkW
February 3, 2018 10:01 am

Don’t think so . I live at the bottom of Lake Agassiz. East of the Rockies. Are you thinking of the Utah scablands floods? I’m guessing that event may have drained to the Pacific.

Reply to  MarkW
February 3, 2018 4:27 pm

Lake Agassiz drained south into the Mississippi until long after the Younger Dryas.
Look up Traverse Gap in Minnesota which is the continental divide point of the drainage system. It is well below the lake level that Lake Agassiz was until about 9,000 years ago after which the Hudson Bay ice-sheet broke down and allowed the drainage to go into the Atlantic. Note this is much later than the Younger Dryas cooling (noting there was Older Druas and an Oldest Dryas cooling events before the Younger).
Just think how crazy wide the Mississppi was during the ice ages especially the summers. There is no way animals would have been able to cross it and humans would have needed the very earliest human-made boats to make it (unless it froze in the winter).

Reply to  mikewaite
February 3, 2018 7:49 am

Yes big freshwater releases in the ocean at high latitudes can interrupt cold downwelling and deep water formation, which are dependent on high salinity.

February 3, 2018 9:13 am

This excellent paper strongly supports the Firestone et al book of 2006 The Cycle of Cosmic Catastrophes: How a Stone-Age Comet Changed the Course of World Culture. Bear & Company. p. 392. ISBN 1591430615.
and paper of 2007
This event was the root source of all the flood myths- trillions of tons of ice from the remnant North American ice sheets were vaporized and then later rained out causing enormous floods. In Siberia mammoth herds were swept away and their remains piled up in debris piles with the whole thing then flash frozen as the temperature dropped dramatically. For good descriptions of what happened with some photos of the debris piles with mammoth remains See “Cataclysm ” Allan and Delair Bear and Co 1997
The Carolina Bays were carved out probably by enormous chunks of ice blown off the ice cap over the Great Lakes .All the megafauna vanished and the Clovis culture ended. An exciting event for Geologists to reconstruct in the comfort of the 21st century. However had the 1908 Tunguska event occurred about 10 minute earlier London might have disappeared!! We feel safe only in our ignorance – best not to think about it
and believe we can control CO2 to save us from an imaginary global warming catastrophe.

Reply to  Dr Norman Page
February 3, 2018 10:19 am

The global rise of sea level by 100m over a few centuries at Holocene inception would surely provide ample basis for flood myths in human memory. During this Holocene flood there came a moment when the Bosphorus straits leading to (what is now) the Black Sea was overtopped by rising sea level. A catastrophic flooding followed which innundated human settlements in a matter of days.
I see no need or basis for attribution of all flood myths to a hypothetical bolide event which is entirely unnecessary to explain anything.

Reply to  ptolemy2
February 3, 2018 10:48 am

As to the Black sea flood see
This was much later than the early Holocene – about 8-9000 and not catastrophically sudden like the Dryas event
It was probably related to the well documented 8200 year event which drowned the North Sea and Doggerland.
In my first comment it should be 10 minutes later.

ian whittaker
Reply to  Dr Norman Page
February 3, 2018 1:00 pm

Sorry Norman, but that is complete nonsense. Pretty much the whole of the relevant scientific community reject this impact scenario as being completely baseless. For good reasons. There is NO EVIDENCE. I have linked this paper before, but I would very much suggest reading it, and some of the references therein:
The Younger Dryas impact hypothesis: A requiem
Pinter, N. et al.
It is extremely damning. As damning as it is possible to be in the scientific literature. They found zero in favour of this hypothesis. They also found a lot of sloppy work by Firestone et al. Unacceptably sloppy. I would recommend reading that paper to anyone who has been, or is likely to be, taken in by this fantasy.

Reply to  ian whittaker
February 4, 2018 7:12 am

Ian Look at the affiliations of the group of world wide based 21 authors of the Walbach et al paper. It is your statement that “Pretty much the whole of the relevant scientific community reject this impact scenario as being completely baseless” which is nonsense. Your link was published in 2011. For an excellent updated review of the controversy readers should consult
Obviously opinions differ. In my opinion the weight of evidence – including the new Walbach et al papers is conclusively in its favour. You are free to hold a different opinion of course and believe the science was “settled ” in 2011.

Reply to  Dr Norman Page
February 4, 2018 8:59 am

Actually there are many root sources of flood myths: filling of the Black Sea, release of lava dams across the Grand Canyon, the latter ice age events you describe. Another would be the impact caused deluge associated with the formation of Burkle Crater in the Indian Ocean ~ 5,000 years ago. Besides creating a 30-km diameter crater, associated tsunamis, the impact would have lofted a LOT of water into the atmosphere and higher (water depth at the location is 13,000′). Takes a while to rain that much water out of the atmosphere. 40 days and nights? Who knows? But the timing is intriguing. Cheers –

February 3, 2018 10:30 am

[snip – over the top -mod]

Reply to  ptolemy2
February 3, 2018 11:15 am

My “OTT” comment was not a reply to Norman page – but something entirely unrelated (top level post). Still – my bad. Naive, I guess?

Gerard O'Dowd
February 3, 2018 10:58 am

It is doubtful that our human ancestors who lived through the YD impact-caused mini ice age had sufficiently long life expectancies to suffer from skin cancers, regardless of the effect wood burning aerosols and combustion would have on the atmospheric ozone levels. One could easily imagine that the hardy bunch of Homo sapiens sapiens who survived the YD did so by hunkering down in nice warm caves, perfecting their cave wall art work and animal skin clothing lines to enhance retaining body heat, trying to avoid smoke inhalation and not getting much UV radiation skin damage from spending a lot of time in the sun, not that there was much of that either, if the scientific hypothesis of the study is correct.

February 3, 2018 11:32 am

Practically everywhere that archeologists have discovered ancient settlements, they have found some sort of depiction of a certain type of creature. There is also a verbal tradition across the world, apparently independently (and if not independently then that is of great consequence itself), of this same creature playing a huge role in the lives of their ancestors.
The dragon.
Fire coming from the sky to devestate man, flora and fauna. It’s too widespread and common a tale to have absolutely no basis in fact. It wasn’t a creature, but was it a comet?

John B
Reply to  Keith
February 5, 2018 7:33 pm

Quite possible. And the idea has been put forward for a while. As mentioned above the Burckle Crater on the floor of the Indian Ocean fits the bill quite nicely. What many forget is that the tail of a comet always points away from the Sun so a comet on an impact trajectory after perihelion has the head following the tail.
A vast glowing, writhing thing, glowing brighter and brighter, cutting the sky in 2 and then the disaster of impact. I’d be scared of glowing snakes in the sky too.
All cultures have stories of fiery snakes that fly and all cultures have flood myths. Only the Biblical story, the very youngest version worries about rain, all the others speak of the seas rising to cover the land. The Epic of Gilgamesh” specifically says the wind and water came from the south, a flood on the Euphrates would come from the North;
I watched the appearance of the weather–
the weather was frightful to behold!
I went into the boat and sealed the entry.
For the caulking of the boat, to Puzuramurri, the boatman,
I gave the palace together with its contents.
Just as dawn began to glow
there arose from the horizon a black cloud.
Adad rumbled inside of it,
before him went Shullat and Hanish,
heralds going over mountain and land.
Erragal pulled out the mooring poles,
forth went Ninurta and made the dikes overflow.
The Anunnaki lifted up the torches,
setting the land ablaze with their flare.
Stunned shock over Adad’s deeds overtook the heavens,
and turned to blackness all that had been light.
The… land shattered like a… pot.
All day long the South Wind blew …,
blowing fast, submerging the mountain in water,
overwhelming the people like an attack.
No one could see his fellow,
they could not recognize each other in the torrent.
The gods were frightened by the Flood,
and retreated, ascending to the heaven of Anu.
The gods were cowering like dogs, crouching by the outer wall.
Ishtar shrieked like a woman in childbirth,”
I think a lot of the reason that people try to tie the flood to the Black Sea and others is because they do not want to face the idea that impacts are more common than we like to think. We comfort ourselves to think Tunguska was a “one off” by ignoring the explosions in South America in the 1930s and the bolide over America in 1972.

February 3, 2018 11:43 am

In reality, a large meteor came out of the northeast and struck the Laurentide ice sheet over the Great Lakes. This caused a great splatter of slush-balls – low energy soft projectiles that rained down over America forming the CaroIina Bays, a million shallow impact craters that litter the east of America.
We know this because no matter where they reside, all of these Bays are orientated to one position in the Great Lakes. Only a central radiant could do this – a radiant caused by an impact. Is was these slush balls that caused the megafauna extinction, the Clovis man extinction, the Younger Dryas cool period, and the million Carolina Bay impact craters.
See paper ‘The CaroIina Bays and the Destruction of North America’.
Some Carolina Bays…

Reply to  ralfellis
February 3, 2018 11:45 am

Interesting that the impact proxis are centered on the Great Lakes……

Reply to  ralfellis
February 3, 2018 12:25 pm

Great Picture- Thanks

Ted Clayton
February 3, 2018 1:01 pm

The early aviation era highlighted the legitimately-amazing pattern of “Carolina Bays”; oriented & shaped shallow surface-depressions arrayed NW to SE across a large segment of the eastern United States (100s of thousands of ‘weird’ lakes & ponds). Still less than thoroughly resolved.
The Tunguska Event was earlier, but took many years to investigate & affect the popular imagination, making it & the heyday of Bays roughly contemporary. Key imaginative depictions of how a disintegrating snowball comet could have created the Bays generated intense interest in the early 20th Century. For a brief period, a cadre of solid & leading scientists ‘formed a consensus’ that indeed the Bays were astronomical. Validating all the attendant phantasmagoria, both real & factitious.
But even at the time, some saw the fatal holes in the scientific logic, and their arguments & data soon undercut the new & very popular scientific portrayal of ‘Fire From The Sky’. By WWII, it was retired baloney.
Some did not get the retraction-memo. Some were kids and had soaked it up in what was lurid SciFi-like coverage. From then on, there has always been a cadre of people who carry the torch for an astronomical explanation of the Bays … and a ready cover-story for the disturbingly resolution-resistant Younger Dryas, and for an arbitrary assemblage of Continental and Global effects that can be conveniently invoked once a (grazing, fragmenting) comet-strike is accepted.
It’s actually another aberration not unlike the widespread current Belief System that ascribes control of the climate to CO2. Or, the only reason we don’t to this day have a pesky cadre of Eugenics-scientists, is that late adopters in Central Europe defamed it beyond the pale.
[Trying to ‘tag’ the diameter of the putative original incident astronomical object, is a new angle. I suspect this relates to difficulties with the trace elements in the winnowed microspherules that are now the preferred evidence … replacing the previously-preferred char-layers found at Clovis sites. Both these forms of evidence are interesting in their own right … and both are flawed tools (like the original case for an impact-origin of the Carolina Bays) in the assigned role.]

Reply to  Ted Clayton
February 3, 2018 1:38 pm

Thanks – here we are again battling the zombie-like YD impact hypothesis. Your historical perspective is useful. The wiki page on the Carolina Bays (bays refers to trees, not coastal inlets) also gives a history of the academic community’s rejection of the bolide explanation of both the Carolina Bays and the YD.
One problem for the bolide – or any other – explanation of the YD, is the failure of the YD to actually exist. The “YD” refers to a non -entity. What does exist is the Bolling-Allerod – the abrupt warm peak just before the “YD”. From Bill Illis’ explanations above it is clear that the BA was simply number 20 of the 20 Dansgaard-Oeschger events (micro-interglacials) that punctuated the last glacial interval. What has been called the YD is just the interval between DA event 20 and the Holocene inception. Anyway I’ve said enough on this thread – I’ll shut up 🤐 .

Ted Clayton
Reply to  ptolemy2
February 4, 2018 8:53 am

Yes, it’s like the Price of Freedom, Ptolemy. But! At least it’s a guaranteed job! 😉
Let’s review the key basics.
1.) The fascinating Carolina Bays depressions & water-bodies, are not impact-features. They’re very shallow, and the floor & basement materials have not been disturbed. They weren’t made by something hitting the ground.
2.) It’s hard to get a high-quality date-handle on the Bays, but plainly they date somewhere back into the pre-Holocene Ice Age … several times the age of the onset of the Younger Dryas. Part of the reason why it’s hard to get “a” date for them, is that they are not of “a” date. They are of different ages … they were made at different times. Some return different dates for different parts of the same feature, indicating that they ‘grew’, gradually.
3.) Craters are usually circular, despite that they are created by objects coming from different directions. The great majority of impact-objects, indeed, come in at an angle. And leave nice, circular craters. That Carolina Bays have a specific non-circular shape & orientation, is an argument against an impact-cause, not for it.
But let me repeat, that some of the evidence & information that has been uncovered or is being developed, in pursuit of an astronomical impact cause of the Carolina Bays, and the Younger Dryas, is really quite interesting & promising. Seemingly-strange layers of charred organic material in association with known Clovis sites. The screening & washing of microspherules from sediments. These are intriguing, and potentially valuable in & of themselves.
And of course, impacts do happen; they are always spectacular, and sometimes they are game-changers. But … the old expression still applies, that just because you have a shiny new hammer, does not mean that every problem out there is now a nail.
Amateur gold miners, especially those washing fine stream or beach deposits, often recover spherules and other odd & mysterious small objects. You see them with a magnifying glass, inspecting the concentrate in your pan or riffles. Popular gold-recovery methods are ‘fairly’ good at getting these oddities, but there two well-known specialties that use adaptations of the usual methods, to better-recover grains that are not as heavy as gold.
A sometimes-popular specialty is the washing of gravel & sediments for various gem stones. Invariably, this activity is after larger specimens, but if you are in a gem-bearing stream, there will also be small sand, made from the target gem-minerals. So ‘prospectors’ will routinely ‘check’ for fine residues from their target-mineral.
Geologist, mineralogists and geochemists are interested in determining all the constituents of deposits or formations. They use washing-tables that are specialized to effect a graded-separation of everything in the sample, rather than preferentially separate & concentrate only the heaviest (gold & platinum family).
If all you have is your own backyard, or an unguarded nearby vacant lot (street or roof-gutters), dig/scrape up some material & wash it. You certainly will not be the first to find surprises.

Ted Clayton
Reply to  Ted Clayton
February 3, 2018 4:03 pm

Yes indeed, it’s a guaranteed job!
Summarizing the basics of mainstream knowledge of Carolina Bays:
Wikipedia entry:
1.) These simply are not impact-features. Even early, ordinary geology figured this out; confirmed from many angles by fancier, recent methods. Especially, large Bays (miles) are often much too shallow; there is a general lack of any ‘disturbance’ to the floor or basement of these features … much less signs of anything high-energy or high-velocity.
2.) Bays pre-date the current Holocene Interglacial. Hard to get a clean date-handle on them … but they clearly existed back into the last Ice Age. Roughly 2 to 4 times the age of the Holocene – and of the artist formerly known as the Younger Dryas. Some appear to be quite a bit older-yet, suggesting a prolonged & ongoing period of formation. Not all of the same age … didn’t all happen at the same time … ‘grew’.
3.) Craters on the Moon and Mars are round. The impactors came from all angles, often glancing, but left circular craters. It is usually difficult even with close study of an impact-feature to determining much if anything about the incident angle.
There are various efforts to pose a constellation of ‘soft’, ‘low-velocity’ impact-objects, which might better-conform to the fact that nothing fast or hard made the Bays-depressions. The archetypal scenario for this idea is an impact into the Laurentide ice sheet, near or NW of the Great Lakes.
The quick & dirty way to get properly oriented on this scenario, is to place a 10 or 100 megaton nuclear device on or in the Ice Sheet, and detonate it. Does it fling or splash chunks or slush-gobs … across the continent? No, certainly not. Firstly, no weapon has anything like the power to project energetic effects at those distances. But even with the insufficient power of these devices, there will be no tossing of intact chunks, because the energy at ‘ground-zero’ is still far too high to allow chunks or blobs to remain intact. ‘Everything’ near the explosion is reduced to a fine state … all the ice & slush is superheated steam.
The asteroid or comet that could excavate the ice sheet and project ‘designer’ soft masses across North America (and well out into the Atlantic ocean) actually propels the material as a beyond-incandescent gaseous wavefront or ‘rolling torus’.
The crater from this impactor, even after the Laurentide healed-over and flowed across it, would be extremely young, and it would be BIG. It would be as familiar to children as Dinosaurs. Globally famous.
What the Carolina Bays appear to really be, is a version of the ‘patterned ground’ such as seen on the Alaska North Slope … and in many locales today, along the southern terminus of the former continental ice sheets, across the northern United States. Consistent wind coming off the ice was the main agent of the startling orientation seen in Carolina Bays.

Richard Aubrey
February 3, 2018 8:42 pm

if, for the sake of argument, we presume the YD was caused by the release of massive amounts of fresh water into the St. Lawrence and down to the North Atlantic, then we have cold weather. Cold weather does not evaporate as much water as does warm weather. Which explains evidence of massive dust storms along the mid-South Atlantic coast.
If things are that dry, what might be a normal forest fire could become a continental catastrophe. That would explain the biological changes observed.

Ted Clayton
Reply to  Richard Aubrey
February 4, 2018 10:25 am

The winds coming off the northern continental ice sheets must have been amazing, and they would have been arid, having been chilled by the ice and lost their moisture. As I understand it, the main sources of dust & silt, carried south long distances by the winds, were near the southern terminus of the ice. However, it would not be hard for me to see an ongoing ‘push’ and ‘crawl’ of loose dust & fine sand, like a perennial blizzard of dirt, instead of pulses of long-distance transport.
In a very widespread arid regime such as would favor a generalized conflagration, I would expect lack of sufficient water to prevent the strong development of forests. There is evidence (pollen) to inform us of the botany in different regions … but wherever forests would constitute a large fire fuel-load, it would be properly expected that sufficient moisture was available to support such biomes, ecosystems – and species.
Historically, what we pointed to as evidence of such a widespread ignition-mechanism, was the striking Carolina Bays artifacts. At first, we thought these were impact-caused, but with study it soon became clear that they were not the result of impacts.
So … more recently we have seen first the postulation of widespread fire-evidence. Some char-layers have been uncovered, but these were first identified in close association with known human-Clovis sites … and are not found away from such sites, in a distribution that strongly supports any generalized single-event conflagration. [see also, the black-earth deposits of the Amazon … in association with human habitation & primitive agriculture]
Because the ‘big-fire’ postulate is not well-supported away from Clovis sites (but really – what ARE those deposits, at Clovis sites!?), there was a shift to the extraction & trace-element analysis of microspherules … in hopes to support an aerial-burst astronomical object.
The plan with microspherules is to show that something BIG, and extraterrestrial, took place in the sky. But, microspherules rain-down in serious tonnages, all the time, from incoming meteors and from several other kinds of sources. They can be found most-everywhere, anywhere. This evidence obliges us to confess only that – yep – meteorites burn up in the atmosphere, contain characteristic extraterrestrial trace-elements, are subject to astronomical stresses, and the debris falls to earth. Check.
It’s an interesting avenue of investigation, and I especially like that it can be pursued most-anywhere, and by most-anyone. No, you & I can’t do mass-spectrometry … but that isn’t really needed, to interrogate microspherules extensively.
The key to washing-out your own microspherules, is that they are highly motile – they roll & move easily, because they are round. You will spot the occasional such object, while ‘skimming-off’ black-sands concentrates, to spot your few specks of gold. And what you first notice, is that they “move”, while the other little black specks around them, don’t move.

Reply to  Ted Clayton
February 4, 2018 10:38 pm


February 3, 2018 9:06 pm

The Andaman Islanders, 75,000 years old, survived both the eruption of Toba and the younger dryas.

carol smith
February 7, 2018 11:11 am

Is it a coincidence that last time this subject came up three other defenders of the faith turned up to ridicule the idea of an impact event. The names were different but is there a possibility they are the same three persons. The YD impact is a theory. Let us not forget the idea of a lake of fresh water pouring into the N Atlantic and switching the ocean conveyor belt is also a theory. My understanding is that the chap who actually invented the theory is not such a big fan nowadays and yet uniformitarians such as MrClayton and Mr Whittaker seem to be quite happy accepting one theory and not the other. It is also clear, both this time and the last time this subject was aired, none of these people have actually bothered to read what is being said. Clube and Napier’s two books have been out there since the early 1990s. They were profession astronomers working at an observatory. One of them is the co-author of this new paper. I find it strange that commenters on WattsUp are all ready to ridicule global warming and climate scientists but when it comes to other sciences they out in force supporting mainstream views with no hint of scepticism at all. To be a true sceptic one has to look with a jaundiced eye at all the sciences – and not just pick on one of them. Are these three people regular commenters as the earlier ones never showed up after they had ruined the debate. Will that happen again. They are clearly incensed that the YD impact theory has not gone away – and trying their hardest to nip it in the bud. The Clube and Napier theory perfectly explains not just the YD event but also the Oldest and Older Dryas event, another event around 40,000 years ago (where most of the large mammals disappeared – not so many during the Younger Dryas), and more recent events such as the one at 8000 years ago, another at 5000 years ago, and another at the end of the EB age. Don’t take my word for it – read up on the subject. Too many people can’t be bothered to read up on CAGW and that is why we are in the trouble we are. Until more people get themselves clued up on climate the shambles will keep going on – and the same goes for the people above. They are shouting down something they don’t like. Just like Micky Mann does.

Ted Clayton
Reply to  carol smith
February 9, 2018 2:54 pm

Impact-events do happen, they aren’t just an ‘intellectual exercise’. But then too there’s an old saying, that when we get a new hammer everything starts to look like a nail. After becoming better-aware that Earth is – and has been – pummeled by asteroids, an intellectual period ensued in which, eg, extinction and climate are seen as… nails.
But the biggest problem, at the sweeping-view level, is that we now increasingly see Dryas Events as both recurring, and as components of larger climatic processes (“patterns”). Even simply a “Younger”, plainly alludes to an “Older” Dryas. Signs are begining to emerge, that a Dryas-type episode is a normal occurance at the beginning of an Interglacial, or following soon at the end of a stadial.
The cause(s) of these multiple Dryas events are not known; but the key thing to notice is that matching impactors to them will get very tricky.
Another mounting liablity of the Dryas as an impact-effect, is its termination. An impact does a great job of making something happen ‘all of a sudden’. But it does nothing to explain why the termination is also ‘all of a sudden’. That’s weird. The rest of the overall form of the Dryas period is similarly problematic, from the impact-explanation viewpoint; then at the end, it’s totally-weird.
In order to make an impact work in the Dryas-context, we have to ‘shift our story’, to calling it a Trigger. Triggers happen; they too are part of the Story … but neither impact-objects nor trigger/flip-flop phenomena are Magic Hammers.
First the “black mat” deposits, and now the special microspherules are both intriguing avenues of investigation. Both have been developed by YD-Impact enthusiasts, to compensate for the loss of the key evidence for any impactor, which is an identifiable impact-feature excavated in the landscape. Originally we thought the so-called Carolina Bays were the calling-card of an astounding & unique impact-event, and built the Hypothesis around them. Then, the Bays turned out to be something altogether different, not impact-related.
The Younger Dryas Impact Hypothesis survived (barely) the loss of its key & primary Evidence, when what we thought was a half-million craters turned out to be a geological curiosity.
What the idea probably cannot survive, is the reinterpretation of the Dryas-phenomenon as a stock actor in the Ice Age drama.

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