From the University of California at Santa Barbara -By Julie Cohen |
Most of North America’s megafauna — mastodons, short-faced bears, giant ground sloths, saber-toothed cats and American camels and horses — disappeared close to 13,000 years ago at the end of the Pleistocene period. The cause of this massive extinction has long been debated by scientists who, until recently, could only speculate as to why.
A group of scientists, including UC Santa Barbara’s James Kennett, professor emeritus in the Department of Earth Science, posited that a comet collision with Earth played a major role in the extinction. Their hypothesis suggests that a cosmic-impact event precipitated the Younger Dryas period of global cooling close to 12,800 years ago. This cosmic impact caused abrupt environmental stress and degradation that contributed to the extinction of most large animal species then inhabiting the Americas. According to Kennett, the catastrophic impact and the subsequent climate change also led to the disappearance of the prehistoric Clovis culture, known for its big game hunting, and to human population decline.
In a new study published this week in the Journal of Geology, Kennett and an international group of scientists have focused on the character and distribution of nanodiamonds, one type of material produced during such an extraterrestrial collision. The researchers found an abundance of these tiny diamonds distributed over 50 million square kilometers across the Northern Hemisphere at the Younger Dryas boundary (YDB). This thin, carbon-rich layer is often visible as a thin black line a few meters below the surface.
Kennett and investigators from 21 universities in six countries investigated nanodiamonds at 32 sites in 11 countries across North America, Europe and the Middle East. Two of the sites are just across the Santa Barbara Channel from UCSB: one at Arlington Canyon on Santa Rosa Island, the other at Daisy Cave on San Miguel Island.
“We conclusively have identified a thin layer over three continents, particularly in North America and Western Europe, that contain a rich assemblage of nanodiamonds, the production of which can be explained only by cosmic impact,” Kennett said. “We have also found YDB glassy and metallic materials formed at temperatures in excess of 2200 degrees Celsius, which could not have resulted from wildfires, volcanism or meteoritic flux, but only from cosmic impact.”
The team found that the YDB layer also contained larger than normal amounts of cosmic impact spherules, high-temperature melt-glass, grapelike soot clusters, charcoal, carbon spherules, osmium, platinum and other materials. But in this paper the researchers focused their multi-analytical approach exclusively on nanodiamonds, which were found in several forms, including cubic (the form of diamonds used in jewelry) and hexagonal crystals.
“Different types of diamonds are found in the YDB assemblages because they are produced as a result of large variations in temperature, pressure and oxygen levels associated with the chaos of an impact,” Kennett explained. “These are exotic conditions that came together to produce the diamonds from terrestrial carbon; the diamonds did not arrive with the incoming meteorite or comet.”
Based on multiple analytical procedures, the researchers determined that the majority of the materials in the YDB samples are nanodiamonds and not some other kinds of minerals. The analysis showed that the nanodiamonds consistently occur in the YDB layer over broad areas.
“There is no known limit to the YDB strewnfield which currently covers more than 10 percent of the planet, indicating that the YDB event was a major cosmic impact,” Kennett said. “The nanodiamond datum recognized in this study gives scientists a snapshot of a moment in time called an isochron.”
To date, scientists know of only two layers in which more than one identification of nanodiamonds has been found: the YDB 12,800 years ago and the well-known Cretaceous-Tertiary boundary 65 million years ago, which is marked by the mass extinction of the dinosaurs, ammonites and many other groups.
“The evidence we present settles the debate about the existence of abundant YDB nanodiamonds,” Kennett said. “Our hypothesis challenges some existing paradigms within several disciplines, including impact dynamics, archaeology, paleontology and paleoceanography/paleoclimatology, all affected by this relatively recent cosmic impact.”
– See more at: http://www.news.ucsb.edu/2014/014368/nanodiamonds-are-forever#sthash.Jz8DHJU3.dpuf
h/t to David Hagen.
Humans were responsible for the megafauna extinctions. Natural climate perturbation of the glacial maximum followed by the BA and YD probably contributed to this.
Actually, it isn’t so cut and dried as that. The Overkill hypothesis is just one of (now) four competing hpytheses.
1. Overkill
2. Climate change
3. Disease
4. Impact
1, 2 and 3 do not explain why Clovis man himself also went extinct at that same time. It was another 1000 years before others showed up in the record. Overkill people never mention that one.
As to the BA and YD contributing, why didn’t the earlier D-O events – dating back to 110,000 years ago – cause these extinctions?
D/O events occur during glaciation. The YD was during deglaciation, when previously prevailing temperatures were much warmer.
Climate change doesn’t work, since many of the same species survived earlier deglaciations & interglacials. The same pattern of Older Dryas cooling, Allerod warming & YD cooling appear in prior deglaciations, leading to interglacials. The difference between the Holocene & prior transitions was effective human big game hunters.
Overkill advocates most certainly do deal with the effect of over-hunting on humans. There is no evidence that they went extinct after first appearing in North America. Humans are omnivores, not obligatory big game hunters. In fact, human numbers greatly increased after the Clovis/Folsom transition. The two tool industries overlap, so the putative 1000-year gap doesn’t exist.
The impact hypothesis of megafaunal extinction doesn’t explain extinctions in other parts of the world unaffected by a hypothetical impact on the NH ice sheet, unless the YD cooling can be shown physically to have caused the YD. The Null Hypothesis is that the YD is no different from the thousands of other such abrupt climatic shifts in the paleoclimate record of the Pleistocene.
“D/O events occur during glaciation. The YD was during deglaciation, when previously prevailing temperatures were much warmer.”
Actually, D-O events carried over and became known as Bond events, during the deglaciation of the Holocene. Same frequency, and in-phase. With the YD onset being in both sets. MANY people consider this to be the case. It MAY not be true, in the end, but evidence suggests strongly that it is.
“Climate change doesn’t work, since many of the same species survived earlier deglaciations & interglacials. The same pattern of Older Dryas cooling, Allerod warming & YD cooling appear in prior deglaciations, leading to interglacials. The difference between the Holocene & prior transitions was effective human big game hunters.
Overkill advocates most certainly do deal with the effect of over-hunting on humans. There is no evidence that they went extinct after first appearing in North America. Humans are omnivores, not obligatory big game hunters.”
Correct on that last point.
1. 95% of Clovis people lived in the SE USA (based on the number of Clovis sites, which are QUITE numerous)
2. There are ZERO mammoth kill sites in the SE USA.
3. Wouldn’t you think that they would have killed a few mammoths near where they lived?
4. Why would they go out to Arizona and Montana from Georgia or Alabama, just to kill a 5-ton animal – to carry 3 tons home? ON FOOT?
5. There are at last count only FOURTEEN Clovis kill sites. And ALL of them area out of the range of that 95% Clovis site area.
6. N America is like 98 MILLION square miles.
7. Clovis entire history in the world only lasted about 250 years.
8. Lifespans back then were about 25 years.
9. The Overkill Hypothesis was thought of when it was assumed that Clovis ONLY hunted and ate Mammoths and other megafauna.
10. Anthropologists only now are discovering that Clovis hunted and ate rabbits and deer and elk and bear and foxes and raccoons, etc. They ARE revisiting their Mammoth extinction machine understanding of Clovis.
11. Clovis points did NOT come from over the land bridge at Beringia. The tool technology in NE Siberia is another tech altogether.
12. The only close relative to the Clovis point is the Solutrean point from Spain and France. As long as the Clovis Barrier existed (saying that no one was in the Americas before Clovis at 13,300 years ago) there was a 5,000 year gap between Solutrean points and humans in the New World. Since 1997, when the Clovis barrier was broken, human evidence in the New World has been pushed back to more than 20,000 years – about a 2,000 years overlap with Solutrean points – plenty of time for Clovis to develop from Solutrean. So now there are researchers who assert that the Solutrean point came with people from Europe, and the people came much earlier. And if they did, they would have most naturally come to the SE USA – right where we find 95% of the Clovis sites.
“In fact, human numbers greatly increased after the Clovis/Folsom transition. The two tool industries overlap, so the putative 1000-year gap doesn’t exist.”
No. The gap in the sediments is clear, There is Clovis, and then a gap. And then the next artifacts. 1,000 years later.
“The impact hypothesis of megafaunal extinction doesn’t explain extinctions in other parts of the world unaffected by a hypothetical impact on the NH ice sheet…”
Now this one I will give you. I agree. How did that happen? But no one researching the YD has time now to get to that. Give it time. They are too busy dealing with Surovell’s sillinesses. I don’t understand why. They should shrug him off like a fly.
And, of course, you DO know that the Siberian mammoths food supply does not actually live at the latitudes in which the mammoths are found. You know that, right? The flora only live north to about 55°. So THAT problem also needs to be addressed. And its not like the mammoths like were spread out up to the Arctic cost. The vast majority of those found are really close to the coast. And on the New Siberian Islands, too. And in the water in between the coast and the island. And then they need to explain why the ones there on those islands died while the pygmy runt ones 300 k to the east survived.
Yeah, one thing at a time. They really don’t have unlimited numbers of people or grants, so they can only take them in order of priorities.
You are right of course that it is not so simple. However recent research seems to point to human hunting. Note that the modern human arose about 70,000 years ago. So it was after this that they got really good at hunting. If populations such as the Clovis hunted their source of food and clothing to extinction its not so surprising that they went extinct.
The contemporary Inuit herders of caribou in north Canada and the Eveni/Chukchi reindeer herders of Siberia are the survivors of that era, having learned to live with their animals rather than exterminate them.
“You are right of course that it is not so simple. However recent research seems to point to human hunting. Note that the modern human arose about 70,000 years ago. So it was after this that they got really good at hunting. If populations such as the Clovis hunted their source of food and clothing to extinction its not so surprising that they went extinct.”
No. Only SOME recent research seems to point to human hunting as the cause. Just as much work is going into climate as the cause. And less work is also being done on illness as the cause. And you are staring at work right here that points at impact. All FOUR lines are being worked on at this time. You can’t point at only one and pretend the others aren’t happening.
Modern humans rose 200,000 years ago.
If humans were so good at hunting, why only some of the megafauna went extinct via humans? Bison, elk, deer, bears of many kinds, etc., all came through.
Do remember that when the Overkill theory came up, Clovis was only supposed to have been here for about 300 years. N America is 8 million square miles. Just try envisioning not only the hunters had to cover the entire continent in 300 years, but they had to prevent any animals from wandering around the end of the hunters’ line, back to where the hunters just left. How do they prevent that from happening?
Add to that that only 14 Clovis-mammoth sites have been found. And all of those are in the area of N America where 95% of Clovis wasn’t living.
Full text of a 2010 PNAS paper debunking nanodiamonds:
http://www.pnas.org/content/107/37/16043.full
And Ted Clayton gave another one, above, which is http://www.pnas.org/content/109/19/7208.full
That’s a good one, which a disinterested observer would probably find dispositive.
Thanks.
Yes, but thosee are not the last words. Those are responded to with the papers listed above at http://wattsupwiththat.com/2014/08/29/younger-dryas-climate-event-solved-via-nanodiamonds-it-was-a-planetary-impact-event/#comment-1722938
And THOSE papers have not been rebutted – 2 years later now.
The fact that nanodiamonds occur in black mats from comparable climatic transitions stretching back tens of thousands of years at least shows the YDIH false.
Steve Garcia said @August 30, 2014 at 1:10 pm
The links in your previous comment are to blog-pages, not the sources.
Actually those papers have been rebutted. Read the comments in the blogs you cite, or better yet read the recent papers linked here.
Show me one.
from the abstract of milodonharlani’s PNAS link above …
No evidence of nanodiamonds in Younger–Dryas sediments to support an impact event
Research data for study linked in Footnotes.
Your assertion that dust covered with snow does not contribute to melting is wrong.
Snow is not a perfect reflector from the surface, it is white and has high net reflectivity due to internal scattering. That means that a significant fraction of the incoming light penetrates some distance into the snow. (the walls of a snow cave/igloo have to be quite thick to completely block outside sunlight.
Anyone who has lived in snow country knows that in the spring you have snow piles covered with a dark crust as the imbedded dust gets concentrated at the surface as surface layers melt off. My early spring these snow piles will have a black crust on them just a few hours after being dusted with fresh snow as the imbedded dust quickly melts off the snow cover.
Even apparently clean snow sweeps dust out or the air as it falls and this accumulates in the surface melt layer. The return to high albedo after a snow fall only lasts for a few hours to a day or two depending on the sun light intensity. Once we get into late April early May (northern hemisphere) the sun is high enough at temperate latitudes to quickly penetrate deep into a snow layer and melt off the clean white snow cover. Here in Colorado we can lose 6-8 inches of snow a day to such melting and with a little down slope wind to warm things we can lose over a foot of snow a day to rapid melting.
Larry Ledwick said @August 30, 2014 at 12:42 pm
While indeed not “perfect”, it takes less than an inch of snow to turn an asphalt road surface as white as a foot of pristine snow.
Melting from below will be observed on highways, early in the snow-season, but that is usually due to stored heat in the roadbed. Later after sustained cold weather, a light skim of snow will survive on partially-visible asphalt for days.
I do believe that dusting of permanent (or would-be perennial) snow/ice fields is hugely important. I.e., I suspect we could stop or heavily moderate the onset of a full-blown Ice Age, with a fleet of specialized heavy-lift aerial dusters and carefully-developed carbon or soot particles … which were very extensively explored, developed and applied, more than a century ago. The patents are already lined up on the shelf, waiting for us.
But annual snowfall is a different critter from perennial formations, and the timely application of dusts would be required, late-winter, early-spring. Sometimes, the tired flight crews would just have to go back up and do it again.
Proceedings of the National Academy of Sciences PNAS
vol. 111 no. 21, David J. Meltzer et al, E2162–E2171
May, 2014
Chronological evidence fails to support claim of an isochronous widespread layer of cosmic impact indicators dated to 12,800 years ago
Link to data tables, methodology and supporting information, in the Footnotes.
RIP YDIH.
And good riddance, too. Never posit divine intervention (or its equivalent) where a mundane explanation will do. As I wrote above, during the ice age it is likely that the Arctic ice cap was miles thick, maybe even solid ice down to the bedrock. When the Earth started warming, that solid ice cap would initially be undisturbed and so the main part of the planet would warm quickly. But as sea levels rose from the melting of the continental glaciers, eventually the Bering Strait would open again and the solid Arctic ice would be attacked from both Atlantic and Pacific side. Eventually an under-ice channel would connect the Atlantic and Pacific causing rapid ice melting and so feeding of freezing-cold water into the oceans. So the Earth would rapidly cool again. So here’s the question for you all: How long would it take the Earth to melt out that solid miles-thick block of Arctic ice? I’d say, about the length of the Younger Dryas. Once it was all melted, a thousand years later, the Earth’s temperature could rise again to the new warmer level. I suggest previous ice ages would show a similar pattern if we had detailed enough data.
NZ Willy –
“As I wrote above, during the ice age it is likely that the Arctic ice cap was miles thick, maybe even solid ice down to the bedrock.”
Inform yourself of the actual thickness. It was 2 km (about 1.6 miles) and then only at the glacial max, and then only at the thickest point – which was up near the east side of Hudson Bay. Near the fringes it was naturally thinner, and probably thinned quite rapidly right close to the edge.
“When the Earth started warming, that solid ice cap would initially be undisturbed and so the main part of the planet would warm quickly. ”
I love when people invoke this mysterious warming. They don’t explain it. (They can’t, of course.) They just say, “when it warmed”, blah, blah, blah) with absolutely no explanation needed for WHY it warmed. It is taken on faith that SOMETHING did it, but then they blow off actually looking into it.
Hey, I don’t know the answer myself, but it bugs the hell out of me when people just reach into the “reasonable portion of the brain” (meaning their arses), pull out a speculation, and then go on, as if it is now explained from on high.
It’s not a speculation, THAT the Earth warmed. But WHY? Nobody even bothers asking.
There it is in the GISP2 core and others – RAPID freaking warmups and cool-downs, ones that make modern global warming look like a gnat on an elephant’s arse. It is HUGE, and all we have are these PUNY , little micro-forcings like CO2 and cloud albedo, and cosmic rays – none of which are worth SQUAT on the modern global warming stage. But then there are 13°C, 14°C (23°F and 25°F) drops and rises in perhaps a year or so at the YD and everyone goes, “Ho hum,! More global warming (cooling), What’s new?”
WHY it warmed up IS A BIG DEAL. And everybody just sloughs it off with a wave of the magical Harry Potter wand.
“But as sea levels rose from the melting of the continental glaciers, eventually the Bering Strait would open again and the solid Arctic ice would be attacked from both Atlantic and Pacific side. Eventually an under-ice channel would connect the Atlantic and Pacific causing rapid ice melting and so feeding of freezing-cold water into the oceans. So the Earth would rapidly cool again. So here’s the question for you all: How long would it take the Earth to melt out that solid miles-thick block of Arctic ice? I’d say, about the length of the Younger Dryas. Once it was all melted, a thousand years later, the Earth’s temperature could rise again to the new warmer level. I suggest previous ice ages would show a similar pattern if we had detailed enough data.”
Don’t forget that the Last Glacial Maximum ended at 18 kya. That gave it most of the next 5,000 years to melt back – which it did. And it DID re-extend during the YD, but it would have been 1,000 years re-growing areas tht had taken 5,000 years to melt. It is a certainty that the ice had not re-grown its entire thickness.
Now, in Michigan the Mason-Quimby line clearly shows how far down the ice had come – about midway down the lower peninsula. Mammoth bones and paleo-Indian artifacts clearly go that far and no farther. That area did have Clovis. The Gainey site is there.
At LGM the ice had gone all the way down nearly to I-70 in Indiana, if not elsewhere.
BTW, there was an event called the Kankakee outwash (in SW Michigan) similar to the Harlan Bretz Scablands flood, but on a much smaller scale. That is dated basically to the end of the YD. (Which actually doesn’t make sense, because the ice then didn’t go down that far.)
NZ Willy:
Science does have detailed enough data & prior glacials, deglaciations & interglacials do show the same pattern, as I commented before. During deglaciation, outflows of glacial fresh meltwater are implicated in at least some of the sudden cool intervals.
This study found abrupt, millennial scale cooling periods during the long MIS 11 interglacial, for instance. MIS 11 was even warmer & lasted about twice as long as the Eemian, itself warmer & longer in duration than the Holocene so far.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&ved=0CG4QFjAI&url=http%3A%2F%2Fwww.clim-past.net%2F6%2F31%2F2010%2Fcp-6-31-2010.pdf&ei=sjQCVNHjE-WiigKyh4DQAw&usg=AFQjCNHJdGDUmhzh6ipELSw-BLLkXvGGBQ&sig2=KTTbxQ9JTKvgJlfp_-6CBQ&bvm=bv.74115972,d.cGE
Abstract.
A synthesis of paleoclimate responses from Lake
Baikal during the MIS 11 interglacial is presented based on
proxy records from two drill sites 245 km apart. BDP-99 is
located in vicinity of the delta of the major Baikal tributary,
whereas the BDP-96 site represents hemipelagic setting distant
from riverine influence. The comparison of thicknesses
of interglacial intervals in these contrasting depositional settings
confirms the extended ca. 33-kyr duration of the MIS 11
interglacial. The new BDP-99 diatom biostratigraphic record
matches that of the BDP-96-2 holostratotype and thus allows
establishing establishes robust correlation between the
records on the same orbitally-tuned timescale.
The first detailed MIS 11 palynological record from the
BDP-99 drill core indicates the dominance of boreal conifer
(taiga) forest vegetation in the Baikal region throughout the
MIS 11 interglacial, since at least 424 ka till ca. 396 ka. The
interval ca. 420–405 ka stands out as a “conifer optimum”
with abundant Abies sibirica, indicative of climate significantly
warmer and less continental than today. The closest
Baikal analog to this type of vegetation in the history of
the current Holocene interglacial is at ca. 9–7 ka. The warm
conifer phase lasted for ca. 15 kyr during MIS 11 interrupted
by two millennial-scale cooling episodes at ca. 411–410 and
405–404 ka. Reconstructed annual precipitation of 450–
550 mm/yr during the MIS 11 interglacial is by ca. 100mm
higher than during the Holocene; regional climate was less
continental with warmer mean temperatures both in summer
and in winter.
At both drill sites, the two-peak structure of the MIS 11 diatom
abundance profiles reflects the orbital signature of precession
in the interglacial paleoclimate record of continental
Eurasia. MIS 11 interglacial was characterized by the sustained
high level of primary production and accumulation of
autochthonous organic matter at both study sites. The responses
of paleoclimate-sensitive indices in the mineralogy
of the MIS 11 sediments in BDP-96-2 are consistent with
those during the Holocene. Illitization of secondary clay
minerals in the Baikal watershed was an important process,
but it appears to have been subdued during the first half of
the MIS 11, apparently due to elevated humidity and muted
seasonality of regional climate.
hahaha – Sounds like you should go work for Surovell. Especially if you know how to take samples from an archaeological site pit.
NZ Willy
Your hunch about ice cap melting would seem to be a good one. According to Weaver et al 2007 there was a collapse of the Antarctic ice sheet at about 14-15 kya. The big melt wayer pulse from this disrupted ocean circulation with the result that the gulf stream was kick-started. This caused the Bolling-Allerod warming (just before the YD). However ongoing complex interaction between a now-cooling Antarctic (bipolar seesaw) and Atlantic deep circulation resulted in the interruption of the gulf stream a couple of thousand years later leading to the YD. See my post at 5:32.
http://rockbox.rutgers.edu/~jdwright/GlobalChange/Weaveretal_Science_2007.pdf
I love it when people talk about the Gulf Stream and leave out the part where its flow goes INTO the Gulf of Mexico and picks up all its what there.
There is not one oceanic conveyor map in ten that shows it going into the Gulf.
I also find it ironic as hell that you guys are talking about the oceanic conveyor when just now you were all saying how dumb Broecker is/was. Make up your minds…LOL
It is not enough that the Gulf Stream is moving NE like it does. Without the heat from the Gulf it is a totally unimportant flow.
Now, I myself think the oceanic conveyor ans the stoppage of the sinking due to fresh water input – it’s all bunk. I’d love to talk to Broecker himself someday about it.
Why is it bunk?
1. In my engineering career I’ve had to work a little bit with convection. And I will tell you, the second weakest force in nature (next to gravity) is convection. You can argue that if you want, but the point is how WEAK it is.
Cold water sinking is due to convection. But it also has to fight the hydrodynamic lift of the water below that it is replacing. So the downward velocity is dependent on two things – one of which is subtractive.
2. The force of that sinking is supposed to be what SUCKS the Gulf Stream northward like from 4,000 miles. Not even close to being possible. That sinking ias a micro-forcing.
3. The convection downward is the END of the process. The rotation of the earth and the winds are what dives the Gulk Stream. At the end, with counter currents fighting it and whatever, the flow simply peters out. And AS it stop, it has a chance to sink.
4. When you evacuate a region or volume, the lowered pressure allows the fluid to flow to the lower pressure area. But the inflow will come from all possible directions. That means that if the water sinks east of Iceland, half the inflow will be from the northwest and half from the southwest – in fact, from 360° around. It cannot “PREFER” to suck water only from one direction. Suction doesn’t work that way. It scavenges from the EASIEST – meaning the closest. And easiest is not from 4,000 miles away.
I’ve said this to scores of other people, and no one gets it. I don’t expect you to. Only someone with some sort of practical experience with flows will understand the principles involved.
NZ Willy –
“Never posit divine intervention (or its equivalent) where a mundane explanation will do.”
You write about this as if you know how the whole thing aqme about – which you obviously do not.
No one in this YD group had any intention of looking for a comet or meteor strike. Firestone was looking for a supernova in the C14 history. Haynes was just doing his thing at Blackwater Draw. They were led to it by the consistent dating of the samples they kept sending to labs. They kept finding spikes in the uncommon materials in those samples.
They did not wake up one day and decide to go look for God’s hand in the works. But Gradualists will reject anything, any time that in their minds creeps one baby step toward Catastrophism – because science had searched for centuries to get rid of Noah and his Flood, and Gradualism/Uniformitarianism gave them that crowbar. And once they’d won that war, they aren’t going to let “victory” slip from them in the form of anything catastrophic.
So, when Shoemaker-Levy 9 had 20 fragments impact Jupiter in 1994, Gradualists looked at that and walked away. They didn’t see that comets hitting Jupiter could POSSIBLY mean that comets could possibly hit the Earth – not in our times.
And when the rock over Chelyabinsk hit in early 2013, that had no meaning to Gradualists. It didn’t matter that the object came out of nowhere, with no warning – or that the rock could have been 5 tiimes bigger and we could have missed its coming. Or that there are millions of other Chelyabinsks out there that could smack Earth.
And WHY do Gradualists not worry? Because rocks in space are a natural occurrence. And, being a natural occurrence, rocks in space aren’t “Deus ex machina.” RIGHT?
So, who is invoking Deus ex Machina? The YD people – who recognize them as comets and meteroroids (rocks in space), not gods.
NO ONE on the YDIH side is invoking any gods. There have certainly been comets and meteors that have struck the world in its long history. They are rocks, not gods. The giggle is not yours to have. You’ve invoked religion, which nobody on the other side cares a whit about. We have evidence of impacts(though not from any god’s thunderbolts), in spite of the gradualist erosion that has erased most of them. It is real evidence, not holy writ. They are called craters. From rocks. FORMERLY IN SPACE, NO LESS!
(You DO remember when your brethren scientists insisted that rocks do not fall from the sky, don’t you? It’s only been 210- years since THAT one was debunked – by actual rocks falling out of the actual SKY. By the science of the day – the world’s best minds! – rocks could not fall from the sky.)
So, now we are finding out that the rocks in the sky are flying along near the Earth all the time. But of course, such rocks couldn’t fall and hit OUR Earth – our exceptional, protected Earth – could they?
They can hit Jupiter. In fact, since SL-9, two OTHER comets have hit Jupiter – something our BEST MINDS told us would not happen in our lifetimes.
So, either comets hit planets or not. And either comets hit Earth or not – YOU TWO are the final arbiters on that, right? Do our astronomers who spot one coming our way need to ASK you, before announcing it to the world? Will need to get YOUR blessings before they will be allowed to admit it?
CONCLUSION: Rocks fall on planets. They re not gods, nor the emissaries of gods. They are ROCKS.
But if you two want to think they are deus ex machina, go ahead. Others are paying attention to ROCKS.
You two are a riot.
milodonharlani:
Great, so if every ice age ends with a Younger Dryas – type pattern, then the case is closed, there was no impact event. My scenario of the solid Arctic ice cap is an obvious and complete explanation. Well done.
Or?
Good logic as far as you took it.
What is the OTHER side of that logic?
Come on – you can do it…
Steve Garcia
So you are a disbeliever in the Thermo Haline Circulation and the entire discipline of oceanography?
There is one very simple proof that the oceans are vigorously vertically mixed. Bottom water is oxygenated. If the oceans were stagnant as you argue then bottom water would be anoxic. This is tbe case in confined seas such as the Black Sea – hence its name. But most of the world’s ocean bottom water contains oxygen originating from the surface.
Steve, you said that the thickness of the frozen Arctic ice cap was “2 km”, but you’ve forgotten that another few miles of packed ice was likely on top of that, a la Greenland. So 5 miles thick is reasonable. It doesn’t appear on our ice age maps because we have no way to reconstruct it exactly.
“Steve, you said that the thickness of the frozen Arctic ice cap was “2 km”, but you’ve forgotten that another few miles of packed ice was likely on top of that, a la Greenland. So 5 miles thick is reasonable. It doesn’t appear on our ice age maps because we have no way to reconstruct it exactly.”
Well, YOU said ice cap, and I went with that. I meant to say that the ice SHEET max thickness was 2 km.
But, no, nothing I’ve EVER come across indicated that there was a distinction between “ice cap” and “packed ice”. I wouldn’t agree with that statement at all. I know that the INTENT of what I read a few months ago was that 2 km was the most ice at any one point. Where you came up with that “double ice” from I can have NO clue. There was AN ice sheet – the Laurentide Ice sheet at the LGM – and what I am finding now is that that was 2 MILE thick – about 3 km “but much thinner at its edges” [WIki – but no source given]. I will go with that – 2 km or 3 km at the thickest – not that important. It was hard to find more on this right now. But this was interesting:
“the extent and thickness of a wet, deforming bed beneath the southern LIS have been debated. Boulton & Jones (1979) suggested that the south margin of the LIS was very thin because of low basal shear stress (ca. 5 kPa). Beget (1986) suggested a conceptual model for the Lake Michigan lobe that incorporated a combination of sliding and soft sediment deformation. He suggested that deforming till with a low yield strength (ca. 8 kPa) produced ice-surface profiles with an ice thickness of only 500 m about 200 km north of the terminus.”
WOW – 8kPa is only about 1.2 psi – yeah, LOW yield strength for the ground underneath. NO IDEA how that could support 500 m of ice. 1.2 psi is probably like wet slurpy mud. VERY slurpy.
(from http://www.geology.wisc.edu/~davem/abstracts/03-25.pdf)
It evidently is still being debated, as of 2003, at least. 500 meters seems about right 200 km from the south edge. That seems to agree with my sense of it being maybe 100 meters right at the edge, more or less like glaciers calving in Antarctica.
BTW, that 2 miles was for the LIS. The Wisconinan was after the retreat, so it would seem it would be a bit thinner – but I looked a while and couldn’t find specifics for the resurgent ice thickness.
A YDIH article from September in NatGeo:
http://news.nationalgeographic.com/news/2013/09/130910-comet-impact-mammoths-climate-younger-dryas-quebec-science/
Ted and milodon –
It is obvious you two are hard core opponents to this hypothesis.
It should be obvious that we are hardcore supporters of science. No evidence; no hypothesis.
There is nothing the least bit unusual, let alone unique, about the YD. Every deglaciation at least back to 800 Ka shows the same pattern of abrupt cooling & warming.
Please read the papers which have been posted here dispositive of the falsified YDIH & get back to us. Thanks.
For instance, rapid climate shifts in the onset of the Eemian (having already showed same in the super-interglacial, MIS 11):
http://www.sciencedirect.com/science/article/pii/S0277379199000116
Abstract
A study of the 140–100 ka interval in core T90-9P from the North Atlantic (45° N, 25° W), based on analysis of oxygen and carbon isotope records from planktonic and benthonic foraminifera, and from the bulk sediment fine fraction facilitates a detailed paleoceanographic reconstruction of the penultimate deglaciation (Termination II), and of the Eemian interglacial (δ18O stage 5e). The first step of Termination II was characterised by low productivity and a mixed water column, which was a remnant of glacial conditions. A 3 ka period of relatively stable conditions, with a stratified water column (‘Termination II pause’), occurred half-way through Termination II, and preceeded a second and more rapid climatic shift. The end of the deglaciation (Eemian maximum, i.e. isotopic event 5.53) initiated the establishment of strong, seasonal, water column stratification. North Atlantic Deep Water (NADW) production remained low during the complete glacial–interglacial transition. After the Eemian maximum, NADW prodution was restored, and bottom waters remained quite stable during the course of the Eemian, while surface waters gradually cooled in the second half of the stage. A short surface water cooling event accompanied by a reduced seasonal water column stratification and nutrient instability occurred at approximately 117 ka BP.
I did read those, long ago. I’ve been on this for about 6-7 years.
Now, YOU go read the rebuttals.
As milodonharlani states, we are following the science, while you are looking for old-style magic dressed up in science clothing. Just because a rock can fall from the sky does not mean that it did. If previous glacials ended with the same YD pattern as the most recent one, that kills your impact theory stone-cold dead, end of story dead, terminated.
You guys are the ones who brought up deus ex machina.
Also, you seem to be thinking that the only evidence for the YD is the ice core graph. The YD was notable long before they ever drilled those ice cores, dudes.
The YD is NOT “just another blip in the ice cores”.
But NO ONE here – or elsewhere – is even asking WHY those 13°C swings happened – except to invoke microforcings that today have trouble creating 0.2°C swings. Those didn’t happen from CO2, guys (FAR too insignificant), nor from solar insolation as we know it today (too weak), nor from Milankovitch cycles (too long, too slow, too weak), nor cosmic rays making it cloudy a bit more or less (too weak), nor from ENSO (too weak), or the PDO (too weak).
And don’t invoke the D-Os and Bond events – because those are only artifacts of the same graphs you are looking at – from the ice core readings. The patterns are there – but not BECAUSE of D-Os or Bonds – which are only recordings of what actually happened. The temps went up and down severely – at least in Greenland and somewhat less in the Antarctic – but WHY? Pointing at the graph isn’t science. It is looking at a representation.
What did those ups and downs? I don’t know, but the YD is a window into it. Ignore it and pretend vast superiority, but most of this you don’t know much about.
All I’ve heard is paeans to gradualism and Broecker’s conveyor. You think you know about the climate science, but climate science, as we are given it, is in its infancy and has many errors in it. It is not the done deal you imagine it to be. You sound like the science is settled….LOL
Gradualism – do you three actually think that what you see in the ice core graph is GRADUALISM? If so, don’t run around bragging about your powers of perception. 13°swings in less than a decade – and that was done by internal forcings? Think about how illogical that is. The world around you is gradualism. If the world got 13°C colder tomorrow or in the next decade (the YD happened much faster), how much will that shake your understanding of the world? That is what Clovis man faced – and something in there did him in, along with some of the animals he hunted. And it shouldn’t have – because humankind had lived most of its life in ice ages. So, you say it was the cold that got him? I sure as hell don’t. I guarantee you it wasn’t gradualism that killed him off.
Steve Garcia
August 30, 2014 at 2:21 pm
Geologists today are neither uniformitarian “Gradualists” nor catastrophists. It has been understood for decades, at least, that both schools of thought are valid. Even Lyell acknowledged that events such as floods can & do occur, with geological consequences.
That’s not the issue here. The point is that there is not enough evidence to support the YD Impact Hypothesis, & overwhelming evidence against it.
Again, please read the recent papers showing the nanodiamond conjecture false, upon at least two separate grounds. And please respond to my previous comments on the pattern of megafaunal extinctions, both in the Americas & on other continents.
To mention again one example I cited, consider the demise of the giant ground sloths. While wiped out on the North & South American mainlands early in the Holocene, they survived for another 6000 years on Caribbean islands, until in their turn seafaring humans apparently wiped them out there as well. Ground sloths, it should be noted, inhabited the continental tropics (& south temperate zone) in environments similar to those on the islands, even farther away from the alleged impact site in Quebec or thereabouts.
http://www.pnas.org/content/102/33/11763
Asynchronous extinction of late Quaternary sloths on continents and islands
Abstract
Whatever the cause, it is extraordinary that dozens of genera of large mammals became extinct during the late Quaternary throughout the Western Hemisphere, including 90% of the genera of the xenarthran suborder Phyllophaga (sloths). Radiocarbon dates directly on dung, bones, or other tissue of extinct sloths place their “last appearance” datum at ≈11,000 radiocarbon years before present (yr BP) or slightly less in North America, ≈10,500 yr BP in South America, and ≈4,400 yr BP on West Indian islands. This asynchronous situation is not compatible with glacial–interglacial climate change forcing these extinctions, especially given the great elevational, latitudinal, and longitudinal variation of the sloth-bearing continental sites. Instead, the chronology of last appearance of extinct sloths, whether on continents or islands, more closely tracks the first arrival of people.
Okay – Paper read and digested. All of the dates presented were uncalibrated C14 dates BP, so I had to convert to real time, calibrated (via IntCal13). So the “cal BP” dates below are mine and I can defend them, even if they are slightly off. You can go check my work using the paper and IntCal13.
“Years BP” numbers are generally about 2,000 years lower than cal BP dates. So, if you thought any of these lived for 2,000 years after the YDB, you are mistaken.
Basically the paper is an anti-climate-forcing argument, in favor of Overkill. It says nothing about impacts.
In the Supplmental Text, this is discussed in the preamble to that:
Thus, some late dates need stronger provenance and are suspect.
Hahaha – You know where I am going with THAT one, don’t you?…LOL
Seriously, though…
All the dates actually presented (in the main body or in the supplemental text) were 12715 cal BP or before. The text in the conclusions states that, “no remains of megafaunal sloths or any other large, extinct mammal in either North or South America have been reliably dated to within the last 10,000 14C years (≈11,600 cal BP)” – which seems to be the only calibrated date given. However no source for that date is given.
Almost all the dates are 12,600 cal BP or earlier, and only 2 at that date. The rest are either right on the YDB or earlier.
So, the question comes up – Where does that 11,600 cal BP come from? (“Trust but verify”.)
And the other is how can we explain the 12,175 and the 12,600 cal BP dates within an impact scenario? IS that impossible to do?
I don’t know. (I don’t have unlimited access to papers – paywalls and all that.) The animals would all not have died at the same second. If some resources survived, some animals would have found them. Could they live for 200 years in some locales. I have no idea. If the resources are there and they stayed and the resources kept growing, why not? Could isolated families have survived for some time? I have no idea.
Am I clutching at straws? No. I am not gooiing to draw conclusions basd on one paper. (You can’t believe the wide assertions made in so many papers – all over the maps, and so many contradicting each other. If you haven’t run into that you live in a sequestered world.)
This is the first paper I’ve seen in quite a while with actual dates. I have a LOT of other things I read, and this i but one of many to go after. That is one of the FUN things about the YDB – its tentacles go everywhere, so I am not often bored.
There were 32 other megafauna species that went extinct at the YDB. Until I look at enough of them, I can say these dates may be outliers.
I have a PARTY to go to! GOOD BYE FOR TONIGHT, GUYS!
Steve Garcia
August 30, 2014 at 2:40 pm
Clovis people in the SE US killed & ate the animals available to them. There were mammoths in FL, but much of the environment in the SE was not ideal habitat for mammoths. However, there is a pre-Clovis mammoth kill site in WI, & a mastodon site in WA.
http://www.sciencemag.org/content/334/6054/351.short
As for your unfounded assertion regarding the supposed depopulation of North America, please read this recent JAS paper. The Clovis & Folsom peoples might have been of different geographical origin, but they clearly overlapped in time on this continent:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCgQFjAB&url=http%3A%2F%2Fwww.unm.edu%2F~marcusj%2FCollard%2520et%2520al%25202010.pdf&ei=xEcCVP2rPMPiiwL8uYDADg&usg=AFQjCNGEwkebuty9RmvhtgFmlw53lkCHpw&sig2=NUEPPoRLuzOCb9McOdil2A&bvm=bv.74115972,d.cGE
Spatiotemporal dynamics of the Clovis-Folsom transition
a b s t r a c t
Despite the importance of the CloviseFolsom transition for understanding the history of western North America, its spatiotemporal dynamics remains unclear. Here we report a three-part study in which we investigated the transition using radiocarbon dates from Clovis and Folsom sites. In the first part of the
study, we used dates from Folsom site-phases to determine when and where Folsom originated. In the second part of the study, we employed Clovis and Folsom dates in analyses designed to determine whether Folsom spread via demic diffusion or cultural diffusion. In the third part of the study we investigated the velocity of the Clovis-Folsom transition. The analyses suggest that Folsom first appeared around 12,800 calBP in the northern High Plains and spread north and south from there. They also suggest that the spread of Folsomwas, at least in part, the result of population expansion. In addition, the
analyses indicate that the spread of Folsom was relatively fast for a prehistoric diffusion but well below the maximumvelocity that has been estimated for such events. These findings, in turn, have implications for the hypotheses that have been put forward to explain the CloviseFolsom transition. They refute the
idea that the CloviseFolsom transition resulted from an extraterrestrial impact over northern North America at 12,900 100 calBP but are consistent with the alternative proposal that the transition was a response to climate-driven environmental change.
Steve Garcia
August 30, 2014 at 2:56 pm
If Clovis people didn’t hunt mammoths, why do Clovis points show up at mammoth kill sites, as at the classic Lehner, Colby & Naco sites, for instance?
Now you’re getting downright nonsensical.
Who said that Clovis did not hunt mammoths at all? I didn’t. You aren’t reading me clearly. It doesn’t help if I say something and your brain twists it around
What I said was that of the 14 mammoth-Clovis kill sites not ONE was in the normal Clovis homeland in the USA SE. The nearest were up in MN near the headwaters of the Mississippi River.
What all that means I don’t know, but why are there no Clovis-mammoth kill sits in the USA SE? There are HUNDREDS of Clovis sites in the SE, but no mammoths included. And what in the hell were Clovis people doing so far from home killing animals that weighed 5 tons or so? They certainly didn’t take it all back home to Alabama with a banjo on their knee.
I hope that is a little clear to you now.
Your confusion arises from your mistaken belief that all Clovis people lived in the SE, which it should have been obvious they didn’t. Clovis people lived all over the present USA, not just in the SE, as should be obvious from where their points have been found. Do you seriously imagine that western mammoth kills were made by bands immigrating from the SE, to return there?
If so, you really ought to study archaeology & paleontology before presuming to comment upon those subjects.
Few if any mammoth kill sites have been found in the SE for the simple reason that there were fewer mammoths there & the environment didn’t favor site preservation as well as in the West. Clovis hunters in the SE favored other game species because they were more plentiful & easier to kill.
Please elucidate whatever point it is that you are trying to make.
Anthony, it would be worthwhile to do a followup on this, either authored by milodonharlani or using the materials & citations provided here by him. YD was not an impact event because previous glacials also ended with a YD pattern, it seems — which would kill the impact theory “stone cold” dead.
Ted & others have also posted valuable comments with links to studies debunking in detail this hypothesis, including yourself & Phlogiston, et al.
It’s been a lively review here of the broader debate that’s been ongoing across several science-disciplines, for several years now.
One of the reasons this debate gets attention, is the level of public interest in the topics it touches on.
This, updated in 2011, is a pretty good overview, IMO, but important papers further decisively debunking the YDIH came out in 2012, 2013 & 2014, some linked here, including your citations:
http://www.argonaut.arizona.edu/Clovis_Comet_Debate.html
Very interesting that you go find all the CON papers and don’t bother looking for the PRO ones or the rebuttal ones. Real objective approach, dude.
You three guys are basically trolls then, on here, simply to leave everyone with a bad tste in their mouths. Nice citizenship – force it down people’s throats.
Well, the reality is this:
With or without your subjective approval and closed minds, this issue is being debated and people are being won over by it. Your efforts at giving all of this the bum’s rush doesn’t change any of that. You won’t go actually READ anything that rebuts Holliday, so there is no hope for you.
But one really good thing that came out of this is that I found some great papers last night that support what I’ve been saying. THANKS! And have a nice closed-minded life, each of you. I wish you the best.
Dr. Holliday’s backgrounder was key in helping me see how the issue arose. His wrap-up ties a lot together, and cuts to the chase as straight citation & reference following does not. That’s a great link to include here, milodonharlani!
Steve Garcia said @August 31, 2014 at 3:23 am
It’s a science-debate, Steve, and even more-cleanly so than many of the generally sci-tech issues that arise on WUWT.
But the true locus of this debate is not WUWT at all – it’s the wider, authoritative Science institution & community. They are the debaters. Our role here, is more to just ‘report’ on the debate as it has been unfolding in the official science-world.
It would be undue self-flattery (if not self-deluding), for me to image I am ‘weighing in’ on the actual science-conversation. My role is to “report”, and that’s been my emphasis … looking at top-ranked peer-reviewed journals where the back-and-forth of the actual debate has been recorded, and placed in full public view.
The best we can achieve here, is to bring the science that is being ironed out in the real science-professions, to the attention of the general public, and possibly some media-folks.
To that end, I will continue to ‘abuse’ WUWT with citations to legitimate sources like PNAS.
Steve Garcia
I should point out that my main aim here is not to dispute that comet or bolide impacts may have occurred around the YD. I haven’t researched this enough to say one way or another. However I doubt that impacts can be or need to be a sufficient explanation of the YD since there is a well established and scientifically well grounded body of oceanographic models (yes that m word) this time in close agreement with substantial experimental data (unlike CAGW) showing the BA – YD – Holocene inception as well understood centennial and millenial scale ocean circulation processes. (Sorry for the long sentence.)
These oceanographic processes are currently the focus of a pivotal debate at Judith Curry’s site following from the recent Tung and Chen “the ocean ate global warming” paper. JC is arguing, cprrectly in my view, that in pointing to variation in ocean vertical mixing as an excuse for the pause, T&C have pointed to what is likely to be the dominant mechanism of purely natural climate variability on decadal to millenial timescales. This is being opposed by Gavin Schmidt who says the climate system including ocean is at equilibrium and passive and only changed by outside forcing. This AGW position is extremely weak, lacking any insight into complex dissipative thermodynamic systems.
To summarise, existing knowledge of ocean circulation effects on climate has the possibility to fatally undermine the flawed CAGW passive climate paradigm, now that they have been forced to invoke ocean processes to “explain” the pause. It will do much more than that – it could terminally unravel the catastrophist AGW narrative.
Steve Garcia
BTW how was the party?
I agree that more in the YD would be good. As a period with distinctive climate ups and downs with first an abortive then a “successful” deglaciation, accompanied by good geological and oceanographic data, the YD could serve as a “Rosetta stone” of ocean circulation driven climate change.
This could provide solid underpinning of the null hypothesis of the “normalness” of climate fluctuation, on a range of timescales. For me the terms “climate” and “climate change” are almost synonymous.
Another major interest in the YD of course is the megafauna extinction on which milodonharlani is clearly an authority.
I recently found out that evidence abounds for a 5 to 7 hundred foot tsunami took out the pacific population about this time.
Please tell us where you saw this evidence. Thanks!
Mention of tsunamis led me to Steve Garcia’s post on psychic Edgar Cayce & the Atlantis myth on his New Age Web site:
https://feet2thefire.wordpress.com/2012/06/27/the-dawn-of-civilization/
Oh Lord, I left that Edgar Cayce stuff behind when I turned 20. But “Timaeus” by Plato is still on my bookshelf, wherein Plato states that his accounting is taken from what the Egyptian priests told him — he just passed it on. Chinese whisper rules apply.
Younger Dryas Impact Hypothesis: “I would run screaming away“
John Hawks is Prof. of Anthro at Wisconsin, internationally active at leading digs, and runs a fine science blog, JohnHawks.net.
I knew Hawks had a downbeat post on the YDIH, and returned to look closer. Things went downhill from there, fast. The Younger Dryas impact fizzle? [Oct 2009]
On that post, I clicked on his “Impacts” tag, above the title, for several related posts. The latest, May 2011: “I would run screaming away”.
There, Hawks cites science-writer Rex Dalton’s piece, Comet Theory Comes Crashing to Earth
Both Hawks and Dalton point to multiple serious-to-grave irregularities with the ‘YD Comet Project’.
While there’s lots in those posts … here’s the money-quote, from Dalton:
It was Nic Pinter from whom Dalton got the title-quote, but Holliday’s effort to reach out to the comet-team and the involvement of Walter Alvarez is Dalton’s prize reference.
The heated rhetoric was toned down, by most parties … since right about this time in mid-2011. Since then, what looks like a careful institutional effort has steadily boxed-in the YDIH, on first one factual point and then another.
Unfortunately, Dr. Kennett has steadfastly insisted that his premise is valuable & workable … and he repeatedly finds networks of professionals who collaborate with him … which must represent yet-another important backstory … eg, if there was an impact, Native Americans are off the hook for the extinctions, and relationships with them are very important to anthropologists and others.
Mind you, the overkill-evidence doesn’t quite clear my minimally-convincing bar. My side-bet is, continuing attention to the overkill-hypothesis will steadily weaken it … too.
Nasty. Attack dogs all, aren’t we three? Bringing in anything and everything – especially ancient history of Rex Dalton et al.
All of your stuff you are bringing in is SOOOOOO yesterday – stuff that has LONG since been refuted, rebutted and discarded. You are living in the past, dudes. It’s 2014, not 2009.
And all of those are just babble. What does Hawks, an anthropologist, got to do with impact science? NOTHING.
Nic Pinter is a professor at the lowest of the lowuniversity – the super party school of Southern Illinois University, with a prior CV of little but Mississippi River water policy studies – of levees and flood trends. A lot of qualifications there! Nothing on impact science whatsoever or impact materials.
And what is this “Nic” stuff? Are we being led by the nose, folks? Are we showing our TRUE colors? Are we ACTUALLY hired attack dogs, proxies for Nic” And Vancie boy??
Yes, we know now why you wouldn’t read ANYTHING about the science of impact materials, of the papers upon papers with lab tests and proper sampling and microstratigraphy.
You aren’t here to have an open discussion. You were hired to bad-mouth this hypothesis on behalf of the inter-Daulton-Holliday-Meltzer crowd. Aren’t we proud of ourselves for having been thugs?
TROLLS TROLLS TROLLS…
Oh, for the shame of it.
And stupid enough to expose themselves, too.
YOU ARE OUTED
No Mr. Garcia, these are all quality professionals – scientific & journalistic – responding to scientific-community problems that ought to be exposed. The word for this behavior is “whistleblowers”.
History doesn’t have a “Use By” date. Especially not when it’s still unfolding.
My most-recent PNAS citation is only months old. I & others laid down major counter-indicative peer-reviewed papers throughout the recent years.
Real science has a duty to police itself, and that’s what we’re watching. The Younger Dryas Impact Hypothesis is already clearly-identified science-folly. Hopefully, it doesn’t prove to be worse, which is possible.
TC: “No Mr. Garcia, these are all quality professionals – scientific & journalistic – responding to scientific-community problems that ought to be exposed. The word for this behavior is “whistleblowers”.”
IS THERE ANYBODY ON WUWT THAT AGREES WITH THIS SORT OF SCIENCE?
WUWT is a science site. Edgar Cayce-ites and dreamy New-Agers need not apply, nor AGW attack dogs, nor lefty projectionists. Good day.
Oooh, yeah, are we going to go all AD HOMINEM now?
Getting all personal?
Logical fallacy time?
I love it!
AD HOMINEM – The last refuge of scoundrels and attack dogs.
People here at WattsUpWithThat know all about logical fallacies and especially ad hominem attacks. So go for it. It just digs you in deeper.
Steve, I have no dog in this fight but those three really take the biscuit for being mindless attack dogs. That last outburst of vitriol was uncalled for and shows their true colours. That they believe that pouring salt on the mouth of the Amazon will stop it flowing tells anybody all they need to know. They avoided your rebuttal on their stupid claim. They clearly have not read Wunsch. Keep up the good work.
Ahhh! Wunsch! YES! A VERY level-headed scientist. Good get!
Hey, and thanks for the 3rd party POV comment. It’s appreciated.
If so Ted, why dont you police yourself and apologize to Steve?
Further, If half a degree is such a global warming catastrophe, how come everything alive today, in all its diversity survived such a ten degree event? The original temperature chart in this post shows just how insignificant so called current warming is.
If half a degree has catastrophic global impacts, is it too much to imagine that ten degrees was also global and had effect on marginal climates such as Australia, bringing about similar extinctions there, even though remote from the actual cosmic event?
“Further, If half a degree is such a global warming catastrophe, how come everything alive today, in all its diversity survived such a ten degree event?”
EXACTLY.
“If half a degree has catastrophic global impacts, is it too much to imagine that ten degrees was also global and had effect on marginal climates such as Australia, bringing about similar extinctions there, even though remote from the actual cosmic event?”
THESE are the kinds of questions to be asking. We do NOT know the answers yet, but people are out there, trying.
WOAH, YEAH! THOUGHT POLICE! Oh, are YOU in the wrong place, making the WRONG WRONG argument, boy.
When someone thinks he or she has “to police” science – and that HE is the one to do it (shades of WILLIAM CONNOLLEY!), the game is already lost to him. He only is playing politics.
ON THIS SITE, PEOPLE WHO DECLARE THAT THE SCIENCE IS SETTLED, BOY, ARE YOU IN THE WRONG PLACE AT THE WRONG TIME.
On WattsUpWithThat, EVIDENCE is what counts.
All one can do is put their EVIDENCE up, for the world to see. ONCE. Then leave it to the objective world to look at both sides. The objective world does not need police in science. Evidence is what counts. When new evidence comes in – LIKE THIS PAPER – then you get another shot at it.
And BOTH sides in this have presented evidence, as it has been extracted from the layers of the soil. Both sides are qualified scientists, IN THEIR FIELDS. But regardless of their fields, the evidence doesn’t care. The evidence is the evidence.
An old adage: Good scientists follow the evidence, wherever it takes them. If someone else can’t follow, that is their own weakness.
Good attack dogs don’t care about evidence. They care about damaging the people their masters tell them to go bite.
Man bites (attack) dog.
Like the collapse of the Minoan civilisation. They knew it happened but not how. They had destruction on the coast/beach but did not know how it happened. Then after the Asian Tsunami, the sedimentary evidence left beinld, explained it, a coastal tsunami.
However, a coastal tsunami would not explain the fall, fully. So they looked and dug further. They found Tsunami sediment and wreckage over 100 feet above the beach level. it was huge. Caused major damage to the whole infrastructure, maybe the fleet wiped out (speculation), leaving the survivors open to invasion.
So, the growing body of evidence for a cosmic event, not necessarily an impact, is growing and as such, so is our understanding of what may have happened. Large graveyards of mega fauna exist along with tsunami muck. Just what you would expect if millions of cubic miles of water suddenly rushed across the land from cosmic melted mile thick ice sheets.
Steve; As per usual you’ve asked the wrong questions (the right ones in reality) about the sacred cow and stirred the bull poop. Good for you! I do enjoy the cross banter when it is open and academic on either side but that last round was something else. I bet you’d make one hell of a lawyer.
His idea of a good defense is CAPSLOCK, bold bold bold.
Steve Garcia using The Scientific Method:
Three issues seem apparent here:
1. Is evidence of a cosmic impact about the time of the Younger Dryas (YD) conclusive?
2. What caused the extinction of mammoths, saber-toothed tigers, sloths, etc. in the late Pleistocene?
3. What caused the Younger Dryas.
Each of these is an independent question that may or may not bear on the other issues. If there was indeed a cosmic event near the YD, that doesn’t prove that it was the cause of the YD nor the cause of extinctions. Many of the discussions above mix these issues. In order for the impact hypothesis to be a credible cause of the YD, it must account for all of the distinctive features of the YD. (Remember Richard Feynman’s and Albert Einstein’s caution that it only takes one negative piece of evidence to kill a hypothesis). Well, take a look at the number and magnitude of well documented YD temperature changes and the duration of the YD (1000 years), which cannot be explained by any single or even multiple cosmic events (there are too many climatic fluctuations over too long a time). These effectively kill the cosmic event hypothesis as a cause of the YD.
A comment on the temperature fluctuations and the validity of the Greenland ice cores. Be aware that the abrupt warming and cooling of the late Pleistocene was not confined to the YD but began about two thousand years before the YD and well before the postulated cosmic impact event. These earlier temperature fluctuations were as large or larger than those of the YD. These large, abrupt temp fluctuations do not depend only on the ice core evidence. The ice core data is confirmed by well documented advances and retreats of glaciers on a global scale, the CET temp records, and a host of other temp proxies.
The bottom line remains that you cannot explain the multiple, intense temp fluctuations of the late Pleistocene (YD and older) by cosmic impact.
.
The Older Dryas, Allerod & YD transitions were first identified in lake sediments. The YD requires no ET explanation.
Your summary is correct. I’d add that there is essentially no compelling evidence of an impact at the YD onset. However, even if there were some evidence such that the Null Hypothesis of totally normal & natural abrupt climate change could reasonably be called into question, it would remain to show how an impact could have caused the YD & the Pleistocene extinctions, which occurred both before & after the start of the YD.
The YDIH has been effectively falsified. With each passing year, yet more evidence against it accumulates.
The use of Quaternary extinctions to justify placing special significance on the cause of the Younger Dryas, could diminish with progress on the former (purportedly an effect of the latter).
Disease as a factor in extinction could see breakthroughs, as the application of DNA and other molecular methods shifts attention back to this area. That disease could be involved in extinctions is an old suggestion that has lost popularity* … but current events could be a reminder.
The ages of fossil remains from this die-off are not excessive for biomolecules. Abundant specimens and whole formations have been continuously frozen in the north, with especially good representation of the key affected megafauna themselves.
(* That half of our children no longer die of endemic communicable diseases, says nothing about what goes on in the wild, much less the Pleistocene. Cervid wasting disease, eg, persists for extended periods – years – in the soils and on the browse-sources of affected populations, and have been shown to remain actively infectious. This single disease could exterminate species regionally, and prevent recolonization.)
If this 2012 study has been linked already, I missed it. Please excuse if so:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356666/
Nanodiamonds and wildfire evidence in the Usselo horizon postdate the Allerød-Younger Dryas boundary
Annelies van Hoesel, Wim Z. Hoek, […], and Martyn R. Drury
Abstract
The controversial Younger Dryas impact hypothesis suggests that at the onset of the Younger Dryas an extraterrestrial impact over North America caused a global catastrophe. The main evidence for this impact—after the other markers proved to be neither reproducible nor consistent with an impact—is the alleged occurrence of several nanodiamond polymorphs, including the proposed presence of lonsdaleite, a shock polymorph of diamond. We examined the Usselo soil horizon at Geldrop-Aalsterhut (The Netherlands), which formed during the Allerød/Early Younger Dryas and would have captured such impact material. Our accelerator mass spectrometry radiocarbon dates of 14 individual charcoal particles are internally consistent and show that wildfires occurred well after the proposed impact. In addition we present evidence for the occurrence of cubic diamond in glass-like carbon. No lonsdaleite was found. The relation of the cubic nanodiamonds to glass-like carbon, which is produced during wildfires, suggests that these nanodiamonds might have formed after, rather than at the onset of, the Younger Dryas. Our analysis thus provides no support for the Younger Dryas impact hypothesis.
I believe that is a new reference here, and it is a good one! I read it at the source and saved it. Thanks!
You’re right, Dr. E., that proponents of this hypothesis cannot explain late Pleistocene temperature fluctuations by cosmic impact any more than they can the similar sudden swings earlier in that epoch.
As for extinctions, their temporal and spacial distributions argue strongly for a combination of human predation and climatic effects. Those who advocate climate alone are forced to posit that the Wisconsin glaciation was more “extreme” than the Illinoian or many pre-Illinoisan ice sheet advances, but if anything the evidence suggests just the opposite.
YD Impact Hypothesis supporters have if anything even less going for them than the Climate Team.
“You’re right, Dr. E., that proponents of this hypothesis cannot explain late Pleistocene temperature fluctuations by cosmic impact any more than they can the similar sudden swings earlier in that epoch.”
In case you hadn’t noticed, I’ve said that the proponents are dealing with the empirical (real world) evidence in their own order of priorities. The thing that brought this all to their attention was (and is) materials in the black layer (at the very underside of it) that have VERY high spikes – and at that exact time – and which are almost ALWAYS interpreted as indicating an impact. So, they have to continually show three things: The materials are impact-related, there were spikes, and that the spikes were at that time.
The proponents are dealing with checking that evidence out, over and over, at many sites around the USA, and also in Canada, Mexico, Belgium, and Syria. And that is not even mentioning the evidence in Greenland. None of the other issues matter if the impact evidence (nanodiamonds, etc.) turns out to be faulty. If it is, then it falsifies the hypothesis – which, again, they only came to because of the presence of these materials, those spikes, and THAT time. Had the times been different – as it was for the Carolina bays – they subsequently excluded the particular location(s) the research. As they should. But that did not negate the entire study; the other materials and locations still pointed directly at the YD boundary. And the materials were/are still impact materials.
So far, there is LOTS of evidence that is NOT turning out to be faulty.
And what does that mean? The proponents are not prematurely speculating before they have all the evidence. They are focusing on the impact evidence, period.
But it is clear that AN impact happened at that time, and that its effects reached over an area of 50 million square kms – so it was BIG. Not Tunguska, not Chelyabinsk. Bigger. Why bigger? Black layers exist on all those places I mentioned above. The photos are pretty impressive. Think of 50 million sq kms. Mt St Helens’ ash reached about 22,000 sq kms. (http://www.mountsthelens.com/history-2.html) At Lommel, in Belgium, the black layer is a good 9 inches thick or so in spots. Mt St Helens’s ash was 2 inches at about 300 km away, and then petered out by about 500 kms.
“As for extinctions, their temporal and spacial distributions argue strongly for a combination of human predation and climatic effects. Those who advocate climate alone are forced to posit that the Wisconsin glaciation was more “extreme” than the Illinoisan or many pre-Illinoisan ice sheet advances, but if anything the evidence suggests just the opposite.
YD Impact Hypothesis supporters have if anything even less going for them than the Climate Team.”
The original overall impact hypothesis stands, minus some things like the Carolina bays. Since that time, the proponents are basically just trying to finish collecting empirical evidence – collecting samples and laboratory testing them. Some of it is really boring stuff. As it should be. They are letting the original hypothesis stand for the present, knowing that some of it is now out. They are not saying much beyond the evidence of an impact.
But between you and me, first of all, you left out the epidemic hypothesis for the extinctions. So now there are actually FOUR, not three. And people keep publishing papers on the non-impact hypotheses every year. The impact proponents haven’t gotten to the extinctions yet, thought that was part of the original hypothesis and still is. They just have too much work going on with the materials analyses.
Yes, on a hypothesis this big and complex, at some point some of it may no pan out. It is NOT failing at the present point. Will it fail later on? Possibly. Until the actual science is done, no one knows. They know where the evidence is leading – but it might turn out to be some different effect or accuse, coinciding. Or some combination.
But right now? Dude, there was an impact. A big one. Those materials don’t get created and spike like that
Regardless of your opinion and mine and everyone else here, the proponents of all four hypotheses think they are right, and they continue their work.
Which one you favor (or me) doesn’t matter, you know…LOL
Way less. All that “ACC” claims is change, and lo & behold, there is change.
YDIH has painted itself into a very tight corner. Nothing but cosmic impacts can produce nanodiamond (it’s now made on a normal workbench), and in no other place than a single layer (barring repeat impacts).
That West guy who isn’t West, and who Kennett still praises, he might be up to something. He had to be locked up in prison for awhile, head-tripping a town he worked for.
I won’t be surprised to see this thing burn up on reentry itself.
Don –
“Three issues seem apparent here:
1. Is evidence of a cosmic impact about the time of the Younger Dryas (YD) conclusive?
2. What caused the extinction of mammoths, saber-toothed tigers, sloths, etc. in the late Pleistocene?
3. What caused the Younger Dryas.
Each of these is an independent question that may or may not bear on the other issues. If there was indeed a cosmic event near the YD, that doesn’t prove that it was the cause of the YD nor the cause of extinctions. Many of the discussions above mix these issues. In order for the impact hypothesis to be a credible cause of the YD, it must account for all of the distinctive features of the YD. (Remember Richard Feynman’s and Albert Einstein’s caution that it only takes one negative piece of evidence to kill a hypothesis). Well, take a look at the number and magnitude of well documented YD temperature changes and the duration of the YD (1000 years), which cannot be explained by any single or even multiple cosmic events (there are too many climatic fluctuations over too long a time). These effectively kill the cosmic event hypothesis as a cause of the YD.
A comment on the temperature fluctuations and the validity of the Greenland ice cores. Be aware that the abrupt warming and cooling of the late Pleistocene was not confined to the YD but began about two thousand years before the YD and well before the postulated cosmic impact event. These earlier temperature fluctuations were as large or larger than those of the YD. These large, abrupt temp fluctuations do not depend only on the ice core evidence. The ice core data is confirmed by well documented advances and retreats of glaciers on a global scale, the CET temp records, and a host of other temp proxies.
The bottom line remains that you cannot explain the multiple, intense temp fluctuations of the late Pleistocene (YD and older) by cosmic impact. ”
Now, these are good points of discussion, keeping to the science, to the evidence, keeping to the interpretations of the evidence.
My personal answers to your questions, to the best of my understanding of the current state of affairs:
1. Is the evidence conclusive? I can tell you that the scientists involved are doing their best to falsify the hypothesis themselves. They want to attach their efforts to a solid premise, and if it fails somewhere, they will be the first to say so. There are MANY sides to this, and more than probably a dozen lines of evidence, in several fields. That much work isn’t done in a day.
As Meltzer (skeptic) and Grayson summed up the state of Clovis subsistence hunting in 2002:
In other words, the empirical work has to begin somewhere. And nothing can go forward until that is done.
They are focusing right now on the ones they can test in the lab. Others will have to wait. If the lab results are definitely false, they’re done. But that isn’t happening, so they keep working on it to solidify it – if possible. So far, the lab results on what are normally considered impact markers have consistently come back in the affirmative. But they are not done yet. They keep on finding sites, keep on digging up more micro-stratigraphic samples to test. They are doing due diligence.
(The skeptics’ attempts to empirically test (replicate) for spikes in impact markers was an inadequate attempt – on three fronts that I can recall. First, they failed to sample in the same location. Then they failed to sample a narrow enough layer, so their wide layer included far too much non–YDB material which watered down their results. Then with spherules it was specifically indicated to examine them with an SM, and they looked instead with optical magnification alone – which was warned against, because the necessary features are simply too small. Yet these protocol failure results were trumpeted as “We didn’t find any, so the whole thing is a farce”. That is the gist of the falsification that failed itself. It is not a replication if the protocols are not followed.)
Conclusive evidence is down the road – and we all know that even when some people see it as conclusive other ones will interpret some things with different weightings and assert differently. Conclusively in everybody’s minds is not possible, not without a crater and a big stony or iron-nickel ball in the bottom. Don’t forget, people are still arguing over the K-T event, 34 years later – and they even HAVE a crater.
But the YDIH “team” has done the same sort of empirical tests something like 5 times now, and the skeptics keep posturing in public, pretending that none of the later ones were even done; they point at their original (flawed) replication attempts and publicly even ignore the rebuttals to those attempts. I am not making this stuff up.
2. Extinction causes? Let me count the ways…
There are right now four posited causes of the extinction event for the megafauna. (And please don’t forget that there is some evidence that Clovis man himself went extinct at that time – evidence which is itself being debated.) One most of us have heard since about 1980 – Martin’s Overkill hypothesis, which still claims to be IT – the definitive answer. However, climate folks assert that Overkill doesn’t answer enough, and they’ve got their version of things. Then there are those who argue for some sort of epidemic. Those are the Overkill-Chill-Ill hypotheses. And none of them think the other two are correct. Folks here and elsewhere who assert one is triumphant over the other two are stroking themselves and trying to do science by declaration. That is, in my humble opinion. Then 7 years ago along came the impact hypothesis, and all three of those weren’t happy. But those three all had holes in their hypotheses, so the new kid on the block in some ways tried to answer those holes. But the researchers didn’t start out to do any such thing. That just happened in the process of dealing with the evidence.
So, with FOUR competing hypotheses, the answer to your question is imply that the jury is out, and that none of them has won – or looks like it will win any time soon. Each has what the advocates of the other three think are weaknesses. Pages continue to be put out arguing for each of them.
3. The cause of the Younger Dryas is up in the air. The climate folks are sure it was the stopping of the oceanic conveyer, from all I can tell. The Overkill folks don’t go into the causes of the YD. I don’t think anyone on the epidemic side of the extinction has anything about the YD cause, but I am probably mistaken. The impact folks see some reason to think the impact fills the gap that the others can’t. I’ve been keeping up with the global warming thing for about 15 years (over half of it here at WUWT, where I am continually impressed by the amount of science going on), and I can tell you that no one dealing directly with that can come up with any forcings intense enough to cause a 13°C or so rise. Their models have all the inputs as close to reality as they can get, and they can barely come up with 4°C, but Mother Nature is having a laugh at their expense, because 4°C by 2100 is looking rather dodgy. I’ve heard various lengths of time for the onset of the YD – some as short as a month or so. (The EXIT from the YD is even more problematic.) Can climate as we know it even DO that? That rapidly? Well, the ice cores seem to show that it HAPPENED, don’t they? So, it seems like either something internal to the system – something very big – came along, something beyond all our knowledge, or something came in from outside – something ALSO beyond our understanding. Everybody is weighting the evidence differently and coming up with different interpretations and speculations.
Speculating – guessing – is part of the scientific method. Step one, according to Richard Feynman. But after the speculation comes the devising of ways to test the guess out. That is Step 2. Step 3 is to compare the results with what is predicted. No one has succeeded in a successful Step 3 out of the climate side yet.
The impact people are still in the middle of getting the basic stuff down – what I call the “forensics”. They can go that far for now, and the rest has to come afterward, if that part doesn’t falsify the guess – the impact guess. So far, that part is going well. There is a LOT of forensic evidence. On several lines of evidence. But even after all that is sufficient in their scientific assessment, getting to the WAY that an impact could have created a 1300-year ice age is another story, and will be tackled if and when that is appropriate. No one on the impact side is coming CLOSE to asserting that they won the argument. It is far too early for that. Those impact markers spiking right at the bottom of that black layer keep on being there and passing the lab tests. Bigger picture questions have to wait until the foundation is laid. It is premature to go there. The evidence leads where it leads, but right now every time they come out with a paper the “Daulton gang”, as I call them, screams bloody murder – but then the Daulton gang’s negative papers are full of points that get rebutted. So we re stuck in this he said-she said period of evidence and denial, evidence and denial.
YES, Einstein and Feynman – I brought them up above myself. And one falsifying SOLID piece of evidence – one FAILURE will surely take down a hypothesis. But with this impact hypothesis having tentacles all over the place, where does such falsifying evidence come from? Debate? Of course not. The proper course of action is to get at the basic science and start doing due diligence at the basic level. Empirical lab results is that level, and that is what they are doing. And you know what? So far the evidence is not falsifying. Which is why Kennett is so verbal about proof, that these lab tests support the hypothesis to a high degree, at the (scanning electron) microsopic level. At the chemistry level. At the materials physics level. If the hypothesis says that such and such markers should be found and pass lab tests, and then those markers are FOUND and DO pass those lab tests, is there a more scientific way to start on this? The big guess – the YDIH – predicts the presence of X, Y, and Z and other markers. If those can’t be shown, the YDIH guys will pack up and go home.
Not only are they not packing up and tucking their tails between their legs, but more and more other people are coming on board. You don’t hear about it, but it is happening. Sorry if they don’t make a press announcement when each one sides with them, but they aren’t doing it as science by press release.
You are making arguments at the macro level. Which nI myself love to discuss – but it is not MY research. The YDIH advocates, unlike me, are focusing on the micro level. In general, since the first paper, they have forgone research on the macro level. They chose to go in one direction, the fundamentals first. All of what you argue SEEMS to be true, to you. To me, all your points are arguable – and premature. They will not be prepared to argue or follow up on those aspects until the forensics are convincing to them and to a sufficient number of others. They are pretty accepting that the Daulton Gang will never sign on. But to them the Daulton Gang is yesterday’s news. The Daulton Gang’s attack dogs here keep discussing CON papers from 2009 and 2010 that have long since been rebutted successfully, and which the Daulton Gang and their attack dogs then pretend the rebuttal never happened. They believe that the (rebutted) CON papers are THE last word – and quite frankly, they aren’t. The going over and over of points that have been dealt with is like a yappy dog snapping at one’s ankles instead of an attack dog.
I will tackle the Greenland ice cores in a separate comment, if you don’t mind. This one is already really long. But it is just my take on it, for discussion purposes. Okay?
There is no putative evidence that has not been found riddled with error.
The YGIH Team just keeps reiterating the same already falsified junk.
What evidence do you have that North America became depopulated at the YD? You have, no surprise, studiously avoided responding to the hard archaeological evidence that it didn’t, just as you ignore the reality of the overwhelmingly abundant and still mounting evidence against this unsupported conjecture, which can no longer even be dignified with the term “hypothesis”.
From the original post:
The necessary conditions are more than met by lightning.
The case for the Cosmic event gets ever stronger and much more detailed. I especially like how team deny use the group pat on the back and self induced blindness as their winning argument.
Grey –
There is no winning and losing, really. The facts of what happened are those facts and no others. We are all flying blind, with maybe 1% of the necessary information. The ones flying LEAST blind are the ones doing the empirical science on this topic – which no one who has posted comments here, including me, has done. (Unless someone is here under an AKA.and hasn’t admitted it.)
The wise scientist in such a case starts at the beginning – the fundamental evidence – and begins by trying to collect it, measure it, put it into some semblance of order, and then he sees if it leads to more evidence. Premature conjectures on any side are almost certain to lead to wrong scenarios. That includes gradualism when it is a catastrophic event. And it includes catastrophism when it is a gradualist process. Premature includes selecting ONE out of four or more scenarios when not enough evidence has bee collected and collated. It mostly includes thinking that enough evidence is in, when the subject is complex and only 7 years into it.
One immature thing on the part of the Daulton Gang is that this is so complex that some early conjectures have had to be modified – but the D-Gang keeps on harping no things left behind long ago. The YDB team knew that going in some of it was not going to pan out, but they put it into the first paper, anyway. They thought that those somethings were okay, but the evidence led elsewhere. The Carolina bays was one of those. You don’t find the Carolina bays in more recent papers.
I think it is maybe premature in 2014 for Kennett to say it’s proven. But it was WAY more premature for anyone to ejaculate in [2009] and 2010 that it was dead as a door nail. Upon reading Kennett’s pronouncement above, I knew WHY he did it – to thumb his nose at the Daulton Gang for their silly early pronouncements.
Like global warming, we simply do not have enough evidence at this moment. Probably. I only just got hold of the full new paper, so I don’t know the FULL extent of the evidence yet.
However, one thing is clear: ALL of the “forensic” evidence that exists has been developed empirically by Kennett and that team.*** All the rest is people pontificating based on what they THINK they know and that others – according to them – do not know. I will include myself in that – though, because I HAVE read the YDB team’s papers since 2007, up to this one, I AM at least somewhat informed of empirical evidence that most in these comments here do not know. And if Don Eastbrook is smart, he will read them, too. If he doesn’t, he has no place to comment, because this post is about that paper, when all is said and done. And that paper is additive to the earlier ones.
This hypothesis is a game changer, if it is true. Those who try to squeeze it [into] the old paradigm are doomed to miss all sorts of things in it and THINK that they are superior because of that non-fit telling them that it is wrong. Without rearranging one’s mind about what the previously known evidence (seen in its older paradigm) CAN mean – in a changed context, all sorts of wrong conclusions will be made. Not CAN be made – WILL be made.
And since the empircal evidence at the microscopic level is panning out – OVER and OVER and OVER again – the likelihood of this new catastrophic context is becoming more and more likely to be true. Which is WHY people are coming around to it – pretty much one scientist at a time. I say “scientist” and not “geologist” or “astronomer” or “anthropologist” or “archaeologist”, because since 2007 this has ALWAYS been an interdisciplinary hypothesis, covering all of those and more. Every scientist who comes to this has to go OUTSIDE his own specialty in order to capture the entirety of it. And on those other ‘outer’ disciplines for each, he/she starts out mostly ignorant and has to learn new things.
*** IMHO, people who failed to replicate because they failed to follow spelled-out protocols cannot be considered to have done empirical analysis. In chemistry class, failure to follow protocols gives one a D or an F.
Grey –
Good stuff and a good summary for you – straight from the current paper:
How is that for a fair presentation – even mentioning the skeptical papers?
I would draw attention to the NGRIP ice core – where it actually has the platinum peak and the start of the YD right there at the same point in the ice layers. And that this is exactly what Firestone predicted 7 years ago in his paper that started all this.
The important thing about all their evidence is three-fold:
1. The impact materials
2. The spikes right at the underside of the black layer
3. The carbon dates keep on pointing to 12,800 years ago.
What the impact did is for people to determine later. First they have to show strong enough evidence of an impact AT THAT TIME. It doesn’t matter for no what else the ice cores show. The first order of business is to not screw up the impact evidence, to get it solid as hell.
BTW, if you want to read how this all started, Firestone wrote a book called “The Cycle of Cosmic Catastrophes.” It is available on Amazon.com. It is a very good science book. He just wanted to find out why there was a bump in the Carbon14 calibration curve.
Typo – should read ” It doesn’t matter for now what else the ice cores show.”
The reason I say that is that they need to keep their sights on doing things in proper order. The ice core stuff will still be there later and they will have to deal with it then. Now is not the time.
@Don Easterbrook 8:47am:
“A comment on the temperature fluctuations and the validity of the Greenland ice cores. Be aware that the abrupt warming and cooling of the late Pleistocene was not confined to the YD but began about two thousand years before the YD and well before the postulated cosmic impact event. These earlier temperature fluctuations were as large or larger than those of the YD. These large, abrupt temp fluctuations do not depend only on the ice core evidence. The ice core data is confirmed by well documented advances and retreats of glaciers on a global scale, the CET temp records, and a host of other temp proxies.
The bottom line remains that you cannot explain the multiple, intense temp fluctuations of the late Pleistocene (YD and older) by cosmic impact. ”
Don,
No one can have been involved with this for even three weeks without being aware of the abrupt warming and cooling in the very end of the Pleistocene.
I’ve already stated here that if the YDIH is “forensically” shown to have happened, then I agree that they are going to have to try to explain those other severe warmings and coolings. ESPECIALLY, IMHO, the warming at the end of the YD. All of those are as clear as the nose on ones’ face.
But all of that is putting the cart ahead of the horse. They are in the stage of empirical evidence collecting, measuring, and collating. THAT evidence says an impact happened. To assess WHERE that impact can fit into an overall scenario – that step comes later, if the forensics keep on saying “Impact materials – SPIKE – AT THE YDB”.
These people are not STUPID. They are not sophomores in high school. Some are eminent in their fields – Goodyear, Anderson, West, Firestone, Schultz, and sometimes Vance Haynes. With your PhD you should be discussing this all with THEM, not hanging around WUWT and trying to educate me.
The facts of this WHOLE things are this: SOME researchers and others think this has legs. SOME OTHERS don’t. It is obvious that if they disagree on this that it is
1. Not settled science
2. Supported by at least SOME of the evidence, never mind your opinion and mine.
3. Up to those researching it to proceed?
4. Up to their skeptics then to examine and TEST their measurements, yes?
It is NO the skeptics’ place to pontificate on their own feelings about it, but to TEST the results. PER the specified protocols. And if they disagree with the protocols, THEN is the time to challenge the methodology.
All this here is blather. If you disagree with their methods, take it up with them.
The wrap-up the original post says …
Settles the debate?! D’oh!
Well their hypothesis might challenge the sun and the moon and the stars, but Walter Alvarez, who knows a thing or two about tweaking paradigm-noses, figured their data … supported nothing.
So of course, they got rid of him.
Steve,
Threadbombing, name-calling, upper case shouting, none of these will win a scientific argument. Neither will talk of attack dogs (not to mention revenge of the attack chickens).
One of the hardest things in science is the ability to remain open minded about a hypothesis even after having invested much time and effort supporting it. Die-hard clinging to a hypothesis wont make it any more true or false.
Many AGW warmists are going to have to learn this painful lesson in the years ahead, it is good if we at WUWT can give them some leadership by example with this.
At the end of the day, there are two essential positions in the climate debate. You may be surprised to learn your position is on the side of the AGW warmists. These two positions are:
(1) The “static” climate position (or the Gavin Schmidt position or the AGW missionary position): climate by itself is static, passive and peacefully at equilibrium (like the brains of those who hold this absurd position) and climate CHANGE – a shocking and scandalous anomaly – can only come from an external forcing agent – and it is in your interest financially and politically for this agent to always be man-made;
From the static position if you see a climate change you can complacently jump immediately to the conclusion of human interference with climate.
(2) The “dynamic” climate position (the scientific position): climate as a dissipative nonlinear heat engine is never anywhere near equilibrium, it possesses internal dynamics driven primarily by ocean circulation patterns which can oscillate chaotically and thus variation over many timescales is the expected norm.
From the dynamic position if you see climate change you conclude nothing about any external forcing since your evidence for external forcing needs to be exceedingly strong, in the context of continual natural and normal internally driven climate variation.
Now WUWT is an anti-AGW web site in its overall stance. However many who post here, including Steven Garcia, but also the “peleton” of cyclists arguing for driving of climate by solar cycles, planetary orbital cycles, bolide impacts etc. These scientists are by and large opposed to AGW but their position is essentially the static position since they argue that climate must be forced from outside in order to change. So this position is in fact close to those who argue that only CO2 can change climate.
The alternative position to this is the dynamic position which will eventually be shown to be the correct position, since all that needs to be known about how the ocean can drive climate fluctuations over decades, centuries and millenia has been already well understood for many years.
The eventual general acceptance of the dynamic climate position will be slow but inevitable, it will depend on whether scientists holding the static position can honestly confront the evidence and understand the nonlinear thermodynamics underlying ocean driven climate dynamics, and have the inner strength to turn away from the useless and false static position even if they have invested much time and energy – even entire careers – in the static error. Or if they will just have to slowly die off to unbind the truth for future generations.
What “drives” climate on the scale of tens to hundreds of thousands of years is well established, ie Milankovitch Cycles. IMO orbital and rotational effects also influence climate shorter term, on the scale of hundreds to thousands of years, at least, and possibly decades.
On our water planet, ocean oscillations are also important, but are not totally sui generis. Changes in solar irradiance play a demonstrably large role (as modulated by orbital and rotational mechanics), especially UV, and solar magnetism as well.
Steve,
There is no evidence dispositive of an impact, hence no reason other than blind faith for imagining that one happened at the YD.
The paper discussed in this post simply rehashes the same material already thoroughly debunked since 2007 when this cockamamie hypothesis was first hatched. The YDIH Team has its true believers, or trough-feeding rent-seekers, just as does the Catastrophic Man-Made Climate Change Team. No amount of actual evidence can or will dissuade them.
Your ranting and raving only shows how weak your case is. By “weak”, I mean “non-existent”.
The pack attack, the appeal to authority and the bellicose false accusations. Boy are these guys afraid.
Most prob the same mob that denied the Missoula flood, plate tectonics and the Atkins Diet.
“There is no evidence of an impact” denial and false argument all rolled into one cheap shot
You & Steve are clearly projecting. If indeed you & Steve are two separate individuals.
There is no evidence of an impact. Evidence has to be reproducible. No one but the Team finds any evidence of an impact. All independent studies have shown their supposed “evidence” non-existent, including that conducted by Dr. Alvarez, the author of the K/T impact hypothesis, now a well-supported theory.
You’ve even adopted the CACA Team’s language & character assassination. It’s ludicrous to compare the existence-free YDIH with the Bretz Floods (apparently you’re unaware that there were many, not just one) & plate tectonics.
You’ve got nothing. Nada. Zilch. Zip.
There is no “pack attack” There is just the recognition by scientifically literate commenters that this “hypothesis” is yet another crock masquerading as science.