Younger Dryas, The (YD)

Published March 28, 2025

The Younger Dryas, also known as Dryas III, was a mini Ice Age that lasted from about 10,700 BC until around 9600 BC. It is named after a wildflower called Dryas octopetala that flourished during this relatively short timespan. In Ireland, the event is known as the Nahanagan Stadial and in Britain as the Loch Lomond Stadial. In 2015, a paper constraining the date of the event to within 100 years, using Bayesian statistical analyses, proposed a period between 12,835 and 12,735 years ago^(h).

For about thirteen hundred years the glaciers had been slowly retreating until within a short time-span temperature dropped and they began to advance again. The cause of this cooling is not entirely clear.

CAUSES

One view is that a sudden release into the North Atlantic of vast quantities of freshwater that had been contained by huge ice dams is assumed to have closed down the Gulf Stream, resulting in a twelve hundred year lowering of global temperatures. There is evidence that the change only took one or two decades. The same threat is said to exist today with the possibility of the melting of the Greenland ice cap. It also seems that this YD cooling ended with the same rapidity.

The most popular and controversial theory is that YD was caused by an extraterrestrial encounter. This is now known as the Younger Dryas Impact Hypothesis (YDIH) and can trace is origins back to 2006 (see below). This impact has been attributed to various bodies such as a large asteroid or comet, with Halley’s^(ay) or Encke’s Comets and even a second Moon have sometimes been specified as possible culprits! Others have suggested reduced solar activity^(ag) or volcanism on a global scale.

The November 2013 issue of the BBC Focus magazine [p.30] had a brief article on the impact theory, noting that the northern hemisphere saw a drop of as much as 15°C around 11,000BC. In the absence of a suitable impact crater of the right age, there is still much scientific scepticism^(b).

A recent application of archaeoastronomy by Martin Sweatman and Dimitrios Tsikritsis led them to conclude that the carved symbols at Göbekli Tepe recorded an encounter, involving the explosion or impact with part of Encke’s Comet around 13,000 years ago, which triggered the Younger Dryas Event, (sometimes referred to as the 13kya event) that provided the impetus for the Neolithic Revolution. Sweatman later expanded their work in his book Prehistory Decoded [1621] and an article on the Ancient Origins website^(k). In June 2021, Sweatman had a paper entitled ‘The Younger Dryas impact hypothesis: review of the impact evidence’ published in the journal ‘Earth Science Review’ of the University of Edinburgh^(u).

Kevin A. & Patrick J. Casey also maintain that a globally catastrophic event occurred 13,000 years ago^(j). The kernel of their theory is that originally the Earth had two moons that at some later point collided, producing our current Moon, while the remnant of the second one eventually exploded over North America kick-starting what we refer to as the cooler Younger Dryas period. They are adamant that it was not a comet or asteroid that caused the devastation, and so clash with the conclusions of Richard Firestone and his colleagues.

A somewhat technical paper, published in July 2020, challenges the comet impact theory because of geochemical anomalies, Instead, they argue that the YD event was a consequence of widespread volcanic activity^(s), rather than an impact! Martin Sweatman refutes this in a paper on Graham Hancock’s website⁽ⁱ⁾.

A completely different view is expressed in Rod (Carl) Martin ‘s latest book [1623], where he proposes that the Younger Dryas ended as a result of a catastrophic event. Is it possible that there were two cataclysmic episodes with opposite effects?

John Ackerman, a keen follower of Immanuel Velikovsky did claim that there were two such events related to “the capture of the Moon into its current orbit,” marking the beginning and the end of the Younger Dryas period^(q).

Coincidentally, Professor Emilio Spedicato independently concluded that it was a cometary impact in the North Atlantic that was responsible for the Younger Dryas. Subsequently, when temperatures rose again it resulted in the flooding of vast areas of low-lying landmasses that in Spedicato’s opinion included Atlantis, which he locates in Hispaniola.

In 2020, Tony Petrangelo argued that the Younger Dryas event did not destroy Atlantis, but that it was more compatible with the story of Phaeton^(ac).

A 2014 paper^(ak) entitled Nanodiamond-Rich Layer Across Three Continents Consistent with Major Cosmic Impact at 12,800 Cal BP by Charles R. Kinzie et al., has developed further the idea of this event being associated with the Younger Dryas. In a similar vein is an article^(ai) from Megan Gannon.

Additionally, in early 2017, further possible evidence of an impact at the start of the Younger Dryas was offered by a team led by Christopher Moore of the University of South Carolina, when they identified a distinct layer of platinum in the soil that coincided with the start of YD. Commenting on this anomaly Moore noted that “Platinum is very rare in the Earth’s crust, but it is common in asteroids and comets.”^(e) In 2019, Moore published further data^(m) supporting the extraterrestrial impact theory, based on studies carried out on sediments, which date back 20,000 years, from White Pond Lake, situated in southern Kershaw County, South Carolina. “Other examples of excessive platinum grains have been found across Europe, western Asia, Chile, South Africa(r) and North America.” ⁽ⁿ⁾

The previous year saw two papers published online⁽ⁱ⁾, reinforcing the YD impact theory as a global event and adding evidence that the event resulted in a conflagration that “may have consumed ?10 million km2, or ?9% of Earth’s terrestrial biomass.”

Related to this is a paper by Andrew Collins that draws attention to the ‘Usselo horizon’, a charcoal-rich layer of between 1 and 8 inches, found on all continents, indicating widespread fires, now dated to 12,900 years ago^(l). An additional paper by Hans Kloosterman offers additional background information on the charcoal-rich layer^(ab).

Ice cores from Greenland indicate a further cooling period circa 6200 BC that may be related to the abandonment of many Neolithic settlements during this period. Other periods of abrupt climate change have been identified from 3800 BC to 3500 BC and 2800 BC to 2000 BC.

The fact that Plato’s apparent date for the demise of Atlantis, circa 9600 BC, roughly corresponds with the current, best estimate for the date of the Younger Dryas is interesting but unfortunately not conclusive proof of any direct connection. On the contrary, the fact that Athens did not exist until millennia later would have made it rather difficult to have been attacked by Atlanteans at that early date. In the absence of any supportive archaeological evidence, a linkage between Atlantis and the Younger Dryas will have to remain a matter of faith rather than fact. Interesting but inconclusive.

In December 2014 Graham Hancock raised the issue of a cometary encounter as the cause of the Younger Dryas and its possible association with ancient Egypt^(ah). In 2017, he reviewed the Younger Dryas debate over the previous decade in a lengthy essay^(v). This was prior to the publication of America Before. He finished with the the following comment. “Perhaps the lost civilization that I have spent the last quarter of a century trying to track down had its most significant outpost, possibly even its heartland, in North America in the period BEFORE the Younger Dryas cataclysms of 12,800 to 11,600 years ago?” Hancock is inferring here that there was a single global civilisation, a hyperdiffusionist stance that I consider indefensible.

A short paper by John Patrick Hill offers a theory that requires more than faith to accept it; he wrote “Just over 12 thousand years ago, the world was struck by an immense meteor group. It destroyed all of North America and much of Europe and went weIl beyond……… I found proof to support that the creators of the Giza Three and Stonehenge used the Barringer Crater in Arizona as part of the geometry for their for their massive structures.” Later he reveals that at “Giza, when one takes the distance between the outside corners of the three large pyramids there, that distance is equal to 0.72 miles, the exact distance (diameter) at Barringer.” An extended version of Hills’s paper is available online^(t).

In another paper, Hill^(aa) says that “the Younger Dryas Meteor Event struck 12.8 thousand years ago and it was so large, it is wrote down not only in geologic records but also in holy books, as Noah’s Flood.”

Recent discoveries in northern Sudan of dozens of skeletons, the majority of whom were killed by flint-tipped arrows, have led to the suggestion^(c) they were the result of food shortages resulting from the Younger Dryas that in turn led to warfare over diminished food availability.

In 2020, James Lawrence Powell (1936- ), a noted geologist, author, former college president and museum director entered the Younger Dryas debate with the publication of Deadly Voyager[1911]. In it, Powell offers wholehearted support to the Younger Dryas Impact Hypothesis (YDIH), understandably generating a favourable review from Graham Hancock^(w). Even more important, is that Powell’s book induced a number of heavy-duty critics of YDIH, including Michael Shermer to change their opinion^(x). In 2022 Powell concluded a paper reviewing the YDIH debates with the following; “Finally, we can now assess Sweatman’s suggestion that the YDIH may be ready for promotion from hypothesis to the status of theory. If we combine the definitions of “theory” from the National Academy of Sciences and the American Association for the Advancement of Science, it would read something like this:

‘A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence. One of the most useful properties of scientific theories is that they can be used to make predictions about natural events or phenomena that have not yet been observed.’

Those who have read this article and Sweatman’s have the information to decide whether the YDIH meets this definition. In this author’s opinion, there is a strong case that it does. Moreover, it should not be forgotten that no other single theory can explain the YD and its associated effects.”^(y)

The YDIH is based on the claim that around 12,800 years ago the Earth had an encounter with a very large asteroid or comet that broke up in an airburst over North America and of which some fragments possibly hit the ground directly^(ad).

Many effects have been linked with this event with varying levels of enthusiasm including a suggested association with the demise of Atlantis. Elsewhere, megafaunal extinctions, cataclysmic floods, the disappearance of the Clovis people and the creation of the Carolina Bays^(aj), have all been proposed as consequences of this episode.

In 2006, Richard Firestone, Allen West & Simon Warwick-Smith published the foundations of the YDIH in The Cycle of Cosmic Catastrophes [110]. A year later the hypothesis had a more public airing at the American Geophysical Union Press Conference, Acapulco, Mexico, May 23^(ag). This was followed the same year by the publication of a formal paper in the Proceedings of the National Academy of Sciences of the United States of America^(ai).

Since then volumes have been written on the subject, both pro and con^(af).

Martin Sweatman brought further evidence to bear on this debate in an article^(al)on the Graham Hancock website. This focuses on the investigations at Hall’s Cave in Texas described in a paper by N.Sun et al, where the team concluded that the trace elements found there could indicate a volcanic rather than an impact as the cause of the Younger Dryas cooling! Sweatman disagrees with their conclusions claiming that there seems to be an element of selectivity in choosing data, leading to a wrong conclusion.

2019 also gave us a paper that included an extensive bibliography and overview of the YDIH debate^(an). A Thai site also offers a wide-ranging look at the YDIH^(ae). Conflicting evidence regarding the possibility of the Younger Dryas being caused by such an impact is impartially outlined on many internet sites^(a).

I note that Robert Schoch claims that there is no evidence to support the Younger Dryas impact theory, instead, he believes that “it was most likely due to reduced solar activity at that time, a solar shut-down.”^(aq) Schoch’s wide-ranging critique has been refuted by the Comet Research Group.^(ar)

In 2012, Jennifer Marlon et al published a paper, now made available by her on the Academia website, in which they presents “arguments and evidence against the hypothesis that a large impact or airburst caused a significant abrupt climate change, extinction event, and termination of the Clovis culture at 12.9 ka. It should be noted that there is not one single Younger Dryas (YD) impact hypothesis but several that conflict with one another regarding many significant details.”^(ap)

In 2011, an article by Nicholas Pinter et al offered a critical review of the evidence available at that time, which, from its perspective, did not fully support the YDIH^(ax).

Scienceopen.com is a website offering “A peer-reviewed open-access journal collection covering all aspects of airbursts and impacts on Earth by comets and asteroids”. October 2023 brought the publication of five papers on the subject^(as).

In March 2024, The New York Times Magazine published an updated overview of the history and current status of the YDIH^(at). The sceptical tone of the article includes an interesting look at the psychological drivers behind the popularity of the hypothesis with the general public. It concludes noting that “In a sense, what West and his collaborators think now hardly matters. The hypothesis has already penetrated deeply, and perhaps indelibly, into the public imagination, seemingly on its way to becoming less a matter of truth than a matter of personal and group identity. Nobody I spoke with seemed to think it would go away soon, if ever. West, though, took a measured view. “All we can say is this is a hypothesis,” he said. “It’s still a debate. We may be wrong; we may be right. But only time will tell.”

In April 2024, geoarchaeologist Marc Young published a lengthy article^(au) on Graham Hancock’s website, rebutting arguments put forward by YDIH sceptics.

Sweatman’s support for the YDIH has been challenged twice by archaeologist and geologist Vance T. Holliday and his associates(aw), the latest in December 2024, which was reviewed by Jason Colavito^(av).

(a) https://web.archive.org/web/20130310032309/http://blogs.nicholas.duke.edu/thegreengrok/climatedebate/

(b) http://www.livescience.com/39362-younger-dryas-meteor-quebec.html

(c) http://www.independent.co.uk/news/science/archaeology/saharan-remains-may-be-evidence-of-first-race-war-13000-years-ago-9603632.html

(d)

http://www.researchgate.net/publication/268390328_Nanodiamond-Rich_Layer_Across_Three_Continents_Consistent_with_Major_Cosmic_Impact_at_12800_Cal_BP((5082))

(f) http://www.space.com/17676-comet-crash-ice-age.html

(h) New Paper: Younger Dryas Boundary impact date constrained within 100 years – The Cosmic Tusk (archive.org)

(i) https://www.dailygrail.com/2018/02/a-comet-impact-13000-years-ago-set-fire-to-10-of-the-planet/

(j) https://www.academia.edu/38380799/13k_Theory_Atlantis_Revisited.pdf

(k) https://www.ancient-origins.net/history-important-events/younger-dryas-0012216

(l) http://www.andrewcollins.com/page/articles/Lommel.htm

(m) https://theconversation.com/new-evidence-that-an-extraterrestrial-collision-12-800-years-ago-triggered-an-abrupt-climate-change-for-earth-118244