From the UNIVERSITY OF TEXAS AT AUSTIN
Researchers at The University of Texas at Austin have found that a well-known period of abrupt climate change 12,000 years ago occurred rapidly in northern latitudes but much more gradually in equatorial regions, a discovery that could prove important for understanding and responding to future climate change.
The research, published Sept. 2 in Nature Communications, focuses on the Younger Dryas, a cooling period that started when the North Atlantic Current, an ocean current, stopped circulating. The event caused Earth’s northern hemisphere to enter into a deep chill, with temperatures in Greenland dropping by approximately 18 degrees Fahrenheit in less than a decade.
The event also caused rainfall to decrease in places as far away as the Philippines. However, whereas temperatures in Greenland responded quickly to the ocean current shutdown and subsequent reboot 1,000 years later, it took hundreds of years for rainfall in the Philippines to be affected and to recover.
“We found that the temperature in Greenland is like a small ship that you can stop and turn quickly because of the influence of sea ice in the region, while rainfall in the tropics is like a big ship that takes a long time to course correct,” said Jud Partin, a research associate at the University of Texas Institute for Geophysics (UTIG) who led the study.
The changes in temperature and rainfall are linked to a common cause: the slowdown of the ocean currents in the North Atlantic, which affect climate and temperature as they move warm water from the Gulf of Mexico toward the Arctic. As the world warmed after the last ice age, glaciers melted and diluted northern seawater with freshwater. The resulting change in ocean water density disrupted the current and, in effect, the climate, causing a period of global cooling.
The event also inspired the premise of the 2004 disaster flick “The Day After Tomorrow,” which exaggerates the speed and strength of the cooling by depicting the planet entering an ice age in a matter of weeks after the ocean current collapses.
Although other studies well document the changes in temperature and precipitation around the world, this new study concludes that these changes do not occur or recover at the same rate, as had been previously assumed.
Understanding the relationship between temperature and precipitation in the wake of climate change is particularly important because it previews what could happen if the planet’s ice sheets continue to lose mass and add freshwater to the North Atlantic.
At a conference in Paris during July of more than 2,000 climate scientists, the potential collapse of the North Atlantic Current’s circulation was identified as a possible catastrophic consequence of climate change.
“A slowdown of the ocean circulation is a double-edged sword: If we see some temperature changes associated it … and somehow are quick to act and alleviate the change, then we have the potential to stop it before it impacts rainfall globally,” Partin said. “The longer the circulation event lasts means that it will take that much longer for rainfall to recover.”
The researchers discovered how rainfall in the Philippines was affected by the Younger Dryas event by analyzing minerals deposited in a stalagmite growing from the floor of a cave in Puerto Princesa Subterranean River National Park in Palawan. They found that it took more than 550 years for drought conditions to reach their full extent in the region, and about 450 years to return to pre-Younger Dryas levels after the North Atlantic Current began circulating again. The record suggests rainfall was about 25 percent lower than present levels during the cold snap.
They then compared these findings with previously published ice core data. According to these records, it took a decade or less for temperatures in Greenland to drop by approximately 18 degrees Fahrenheit once the current collapsed and about 40 years to rebound after it returned.
Partin conducted the work with UTIG Director Terry Quinn and collaborators from the National Taiwan University and the University of the Philippines-Diliman. UTIG is a research unit of The University of Texas at Austin Jackson School of Geosciences.
Computational models of the Younger Dryas temperature and precipitation also provided insight into the role of sea ice in Greenland’s abrupt temperature change.
“Sea ice around Greenland acts as a ‘switch,’ causing that region to respond more quickly than the rest of the planet does by insulating the air from heat stored in the deep ocean,” said Yuko Okumura, a UTIG research associate and a co-author on the study.
###
The study was funded by a grant from the National Science Foundation.
So it happened naturally before, but man is causing it now, and we have the power to stop it. Pull the other one.
They studied temperature and precipitation. Hopefully, they got that bit right. The rest is pure speculation using models based on … Dinsdale’s rules. So of course they found what they found. There was nothing else there (ie, in the models) to find.
Dinsdale’s rules?
1 comment up.
And research identified the cause then, and research has identified the cause in the industrial era…mans burning of fossil fuels, the resulting 40% increase in atmospheric CO2, and a corresponding increase in the greenhouse effect. Well established science.
“Well established science.”
No it isn’t.
Stop making stuff up.
@catweazle666
Made up? No, you’re the one making things up: http://climate.nasa.gov
warrenlb
Appeals to authority are not science. There is no published scientific research that has proven the existence or magnitude of anthropogenic warming. If established dogmatic theories fail to match observations from the real world, nothing has been established. Furthermore, catweazle666 hasn’t made anything up, his claim refutes a wild assertion that has yet to be proven. The onus is not on him/her to prove that CAGW is unproven.
@Rob Morrw
Absolute baloney. NASA and every Science Academy confirms AGW. Evidence you’ll find on the NASA link I gave you—unless you are illiterate. When Science concludes AGW, it’s up to a Science D**r to publish his contradictory evidence, which none have done.
Warren,
Why do you keep referring to supposed sources which all here know do not say what you claim?
If you imagine that there are actual data supporting the repeatedly falsified hypothesis of AGW, please present them here. If the data are so abundant, why can’t you ever do as asked over an over again and state what they are, yourself?
Your scientific betters here have shown you evidence after evidence against the failed hypothesis of AGW, for which facts you have no answer. What makes you so anti-science as to reject incontrovertible evidence against AGW while being unable to provide a single shred of real data in support of the fantasy?
Please start by explaining why the planet cooled so strongly all during the first 32 years of postwar CO2 rise. Next kindly tell us why the planet has stopped warming (as it did briefly in the 1980s and ’90s) and is once again cooling despite even more rapid gains in this century.
Thanks.
warrenlb,
The webage you linked to offers no proof, as proof is defined in a scientific context. The first two items of AGW confirmation on the “evidence” page are nothing more than appeals to authority:
“Scientific evidence for warming of the climate system is unequivocal.”
– Intergovernmental Panel on Climate Change
Scientific Consensus
“Ninety-seven percent of climate scientists agree that…” blah blah
The rest of the page also contains no evidence, as evidence is defined. Evidence of the validity of a theory tends to come from observation. Since CAGW theories are incapable of producing a unique forecasting result, they have very little predictive power. And the forecasts produced by averaging of CAGW model outputs have failed to match observation. Perhaps you would be kind to point out the proof that I am clearly too inept to find.
@Gloria Swansong
So you too are taking the position of the monkey covering it’s eyes to make sure it can’t see the evidence, so it can claim it’s not there. You do not impress.
X@Rob morrow
Try ‘evidence’ on the NASA menu. It’s really not that hard to find. And ‘proof’ is for math, not science.
@Rob Morrow
Select ‘Facts’ then ‘Evidence’ on the menu.
Warren,
For the umpteenth time, there are no actual data in evidence to support your baseless assertion of AGW.
Please post them here is you have them. You keep your eyes firmly shut to reality.
Why won’t you reply to the indisputable fact that rising CO2 for most of the time since 1945 has been associated with global cooling rather than warming?
warrenlb: “Select ‘Facts’ then ‘Evidence’ on the menu.”
Warren old bean, you wouldn’t recognise a fact if it scampered under your foetid, slimy bridge, leapt up, and sank its fangs into your snout!
warrenlb says:
NASA and every Science Academy confirms AGW.
As usual, warrenlb misrepresents the issue. There is indirect evidence that anthropogenic global warming exists, and like many commenters here, I accept that AGW is occurring.
But it is simply too minuscule to measure. That’s why there are no empirical, testable measurements of AGW. There’s a Nobel Prize waiting for the first person who produces replicable, verifiable, accurate data that directly measures the fraction of man-made global warming (MMGW) out of total global warming from all sources, including the planet’s recovery from the LIA.
But saying some ‘authority’ or other “confirms AGW” is meaningless.
Is AGW 50% of all global warming? We don’t know.
Is AGW 3% of all global warming? We don’t know.
Is AGW 0.005% of all global warming? We don’t know!
We just don’t know. At all. But the fact that MMGW is too small to measure indicates that it isn’t a problem. And the fact that there has been no global warming at all for almost twenty years is pretty conclusive evidence that at current concentrations, CO2 is not the culprit that the alarmist crowd claims.
Honest scientists admit it when the facts contradict their conjectures. The only honest kind of scientists are skeptics. Draw your own conclusions…
DB,
IMO AGW hasn’t been observed in the real climate system because, if it exists, it is promptly counteracted by negative feedbacks.
Now, researchers recently claimed to have observed the GHE from CO2, but their work is marred by reliance on models. But for the sake of argument, even if increased CO2 is from human activity, and this observation/model reflects reality, the fact is that global temperature has not warmed despite lots more CO2 in the air.
@Gloria Swansong and DBStealey.
I don’t buy the snake oil you’re selling. When amateurs start making claims that contradict peer-reviewed science and claim they ‘can’t see the evidence’ that all peer-reviewed science sees, and all the world’s science institutions confirm, it’s time to hold on to one’s wallet.
warrenlb
Sorry, I did use “proof” incorrectly. Thanks for the help. Now if you could point to the link that shows evidence of theory matching observation that would be super. Oh, and you had better post another link that shows natural forcings are net zero at any time scale, which is a requirement of “consensus” climate theories. Saying that they are zero over long time scales and omitting them entirely from models is the same thing. Every reader here knows that your “evidence”, which you may or may not have even read, let alone understand, is entirely reliant on models which haven’t been validated by observation.
and warren,
You haven’t quoted any peer reviewed research in this thread. Instead you posted a link to NASA’s main climate page as evidence, and you are calling your fellow posters amateurs?
warrenlb,
All you’ve done is make another baseless assertion. But then, you’re an amateur.
Wake me when you find an empirical, testable measurement quantifying MMGW. Until you can do that, you’ve got nothin’ but baseless assertions, and your endless appeals to bought-and-paid-for ‘authorities.
So enough deflecting and misrepresenting. Either post a measurement quantifying AGW, or admit that all you’ve got is a conjecture.
dbstealey: “Either post a measurement quantifying AGW, or admit that all you’ve got is a conjecture.”
“Conjecture”? As good as that?
Downright mendacity would be my take.
And stupid with it.
warrenlb
September 3, 2015 at 3:47 pm
Peer review doesn’t exist in “climate science” and doesn’t work anyway. It’s all pal review and utter garbage.
If you imagine that there really is evidence for AGW, why can’t you state it in simple, declarative sentences?
Why can’t you reply to the actual, observed facts which show the hypothesis of AGW false?
What makes you think I’m an “amateur”? And even if I were, many of the greatest scientists in history were amateurs. Your appeal to bogus authority is laughable.
The charlatan, snake oil salesman Michael Mann isn’t a pimple on the posterior of a real scientist, like Freeman Dyson, if the the good Dr. Dyson, heir to Einstein, will forgive such a rude comparison.
catweazle666,
It’s hard to argue with your conclusion that scientists are mendacious. I don’t really think they’re stupid, though.
Anyway, a conjecture is the first step in the hierarchy: Conjecture, Hypothesis, Theory, Law.
It’s only the starting point; an opinion. A conjecture is an educated guess, nothing more. In general this whole debate is over the conjecture that rising CO2 is the cause of global warming.
The problem that warrenlb and his alarmist folks have is that all 4 of those levels of certainty (not that anything in science is certain) is that each of them must be capable of making repeated, accurate predictions. The higher in the scientific hierarchy, the more accurate the predictions. But they all have in common the requirement that they must be able to make accurate predictions. And not just once; the spike in global T in 1997 was a one-off event. They have been wrong ever since.
The CO2=cAGW conjecture has never been able to make repeated, accurate predictions. Their central assertion, which forms the basis for all climate alarmism, is the prediction that rising CO2 will cause runaway global warming.
That has not happened. In fact, despite steadily rising CO2, there has not been any global warming for the past 18 years, seven months. At what point will they throw in the towel, and admit that their original conjecture has been falsified? Some scientists are already saying that. But there aren’t enough of them yet.
In any other scientific discipline, the abject failure to make any accurate predictions for almost twenty years would falsify a conjecture. Normally, scientists are then supposed to go back and try to understand where they went wrong: why has their conjecture failed so spectacularly?
But that would require them to admit that at current concentrations, rising CO2 causes no measurable global warming. They would have to admit that they were just plain wrong. But since CO2=AGW is their central premise, and the source of the “climate studies” federal money hose and their job security, they have apparently decided that mendacity is preferable to the alternatives.
Also, by now they would realize that such an admission would be a climbdown from their absolute certainty that their original conjecture was right — and at this point, that’s what it would be: a climbdown. They have waited far too long; the evidence keeps piling up against them.
Instead, they should have gone with Dr. Phil Jones’ statement that if no global warming resumed for 15 years, that their conjecture was wrong. But $1 billion+ in annual grant money shouts a lot louder than the skeptics of dangerous man-made global warming. And of course the media plays a part in what is now simply a hoax.
So now they’ve switched gears. They rely on warrenlb’s ‘Appeal to Authority’ logical fallacy, and on baseless assertions, and they use other non-scientific arguments in place of the only evidence that would rescue their conjecture: verifiable measurements of AGW, and/or repeated, accurate predictions. But they don’t have any real world evidence. All they have are their repeated assertions that they’re right.
I don’t think they’re stupid at all. They know what they’re doing. Yes, it’s mendacious, and it harms science in the long term. I used to believe that NASA was above reproach. I used to look up to all priests, and especially the Pope. I used to believe that cops were honest.
But like Lily Tomlin famously said: No matter how cynical you get, it is impossible to keep up.
dbstealey: “I don’t think they’re stupid at all. They know what they’re doing.”
If they have effectively bet their entire credibility on a prediction that is as much of a hostage to fortune as global temperature, they are not very bright, no matter how intelligent they are in their narrow field.
Do not equate academic excellence with non-stupidity, I have known a number of incredibly academically intelligent individuals with enough PhDs and professorships to paper a decent sized living room who are truly not fit out on their own. Some of their life choices demonstrate levels of truly Olympian stupidity, in fact.
DB,
The conjecture was born falsified. The cooling after WWII despite rapidly rising CO2 falsified the AGW (thought beneficial) hypothesis proposed in the 1930s. The cooling of 1945 to 1977 also pre-falsified the AGW conjecture spewed in the 1980s and ’90s.
Gloria,
You’re right about the conjecture being falsified, but the man-made global warming narrative was on the back burner for a long time.
Like a lot of folks, I began to pay attention when the great El Nino of 1997 caused global T to rise very fast. I tried to keep an open mind, but that event was not followed in later years. CO2 kept rising, but temperatures didn’t. And then Anthony Watts started investigating the government’s Surface Station network, which showed that its numbers were simply unreliable. They were giving us tenth and hundredth of a degree temperature records, when a majority of the stations were off by 2º – 5º or more.
I worked in a Metrology lab, and we recieved all the current literature, gratis, from instrument vendors. When I began that job in 1973 global cooling was in the news. That didn’t happen, either. Now my attitude is, ‘I’ll believe it when I see it’, whether it’s cooling or warming. For almost 20 years now, it’s been neither.
The big difference now is the really huge amount of money propping up the scare. It wasn’t anything like that in the ’70’s. I have no doubt that if that money flow was cut off, the ‘dangerous man-made global warming’ scare would promptly disappear. Because it’s all based on smoke, mirrors, assertions, and endless appeals to bought-and-paid-for ‘authorities’.
DB,
In the 1970s, global cooling had already happened for three decades. The issue was whether the world would continue cooling.
The AGW conjecture of the 1930s had been shown false by the pronounced post-war cooling, yet given the short memory of AGW proponents, the already falsified proposition was revived in the 1980s. But now alleged man-made warming was considered scary rather than beneficial.
As I’ve mentioned before, a leading proponent of beneficial AGW in the 1930s, Callendar, had to admit that his conjecture was falsified by the severe cold of the 1960s, particularly the winter of 1962.
But Hansen, et al, not being climatologists, either ignored or didn’t know about the extreme cold of the ’60s and ’70s. How they could have missed the many reports by government scientists in the 1970s predicting more and worse cold, however, I don’t know.
And of course you’re right that now a vast, global conspiracy and academic-government-Green-industrial complex is supported by the AGW fantasy.
I wonder if the Single Stalagmite is as telling as the Single YAD tree and if it has a bladed end?
There is a definite problem where the sampling size = 1 or the sampling area = 1
“There is a definite problem where the sampling size = 1 or the sampling area = 1”
Certainly makes it easier to prove a point, as it eliminates any nasty sample correlation issues when N>1
It is called the New Statistics of Climate Seance and it involves a round table of half spiritualists and the other half climate seanceists with the latter being funded by huge grants from NSF, DOE, NOAA, NASA, etc., etc. of which they impart a minuscule amount of the grants (say a $million or two which is in the accounting uncertainty of the Green $Blob) to the spiritualists and their publicity agents.
All it takes is one Ouija board for each scientific conclusion. Samples of size 1 are most appropriate for this “Round Table Group”.
Perhaps they are Scientists of the Church of Scientology
Found the Hockey Stick
http://i189.photobucket.com/albums/z159/BMAONE23/hocky-stick_zps9tbemlbi.jpg
It was right in front of me
“seanceists”
I’m definitely stealing that one.
Sometimes the comments section tops the articles, lol – that is fantastic! 😀
the Church of Scientology
=====================
the Church of Scientology is tax exempt no less. You are likely not. So who has the last laugh?
if the government was giving away $1 million dollars for every one armed, one legged person, within a very short time 1/2 the country would be cutting off arms and legs.
I found a few other other things in that photo but they definitely were not hockey sticks.
I used to smoke 10 packs of cigarettes a day till I got lung cancer. Had half of my lungs removed…So now i’ve cut my smoking in half and only smoke 5 packs a day. Works out pretty good too. Saved 1/2 the money.
“A slowdown of the ocean circulation is a double-edged sword: If we see some temperature changes associated it … and somehow are quick to act and alleviate the change, then we have the potential to stop it before it impacts rainfall globally,” Partin said. “The longer the circulation event lasts means that it will take that much longer for rainfall to recover.”
Climate science can now control ocean currents.
And they say nothing about the drainage of the lake Agassiz into Hudson bay, which stopped the North Atlantic current.
More likely via what is now St. Lawrence seaway. The scour was powerful, and the extent of seafloor sediment fan supports the hypothesis. No Lake Agassiz, no possibility of another such event. Melting and calving glaciers are just too slow.
There really isn’t much support for the idea that freshwater flows from the Great Lakes or Greenland actually suppressed the NAC. That was a popular idea decades ago, much less so now. For instance see Jim Steele’s recent article on the “Arctic Iris Effect” here on WUWT.
That’s still the standard explanation for the cause of the YD (from 2008):
http://www.ncdc.noaa.gov/paleo/abrupt/data4.html
What caused the Younger Dryas?
The Younger Dryas occurred during the transition from the last glacial period into the present interglacial (the Holocene). During this time, the continental ice sheets were rapidly melting and adding freshwater to the North Atlantic. Figure 6 shows the reconstructed freshwater flux from the melting Laurentide ice sheet through the St. Lawrence River. Just prior to the Younger Dryas, meltwater fluxes into the North Atlantic increased dramatically. In addition, there was probably a short-lived period of particularly high freshwater flux about 13,000 years ago that is not shown in this figure, resulting from a large discharge of freshwater from a glacial lake in North America. Scientists have hypothesized that meltwater floods reduced the salinity and density of the surface ocean in the North Atlantic, causing a reduction in the ocean’s thermohaline circulation and climate changes around the world. Eventually, as the meltwater flux abated, the thermohaline circulation strengthened again and climate recovered.
The record from Dome C in Antarctica supports this explanation. If the thermohaline circulation were to slow, less heat would be transported from the South Atlantic to the North Atlantic (Crowley, 1992; Broecker, 1998). This would cause the South Atlantic to warm and the North Atlantic to cool. This pattern, sometimes called the “bipolar see-saw”, is observable when comparing the GISP2 and Dome C records for the Younger Dryas.
Notice the second period of large freshwater discharge following the Younger Dryas in Figure 6. Interestingly, this discharge did not cause a second major climate change similar to the Younger Dryas. One possible explanation for this is that, after the Younger Dryas, the thermohaline circulation had become more vigorous as the climate finally entered the interglacial. A vigorous thermohaline circulation might be less susceptible to freshwater discharges.
Some important datasets related to the Younger Dryas:
Alley (2000), Temperature and accumulation from the GISP2 ice core in Greenland
Hughen et al. (2000), Sediment grayscale from core PL07-58PC in the Cariaco Basin
Lea et al (2003), Sea surface temperature in the Cariaco Basin inferred from Mg/Ca of forams
Wang et al. (2001), δ18O measurements from Hulu Cave in China
EPICA Community Members (2004), δD measurements from the Dome C ice core in Antarctica
Duster (@6:55) gets it right. There were many outlets for the water coming off the ice as it melted. Two that frequently get lost are : The Columbia River on the west coast and, the Mohawk/Hudson on the east coast.
For the first search for: Missoula Floods
For the second search for: Glacial Lake Iroquois
Other flows were north to the Arctic Ocean and south to the Gulf of Mexico.
err? theres a lake up that way somewhere growing very large , I read about it some yrs ago
its swamping towns n farms
I thought it was Agazziz reforming?
anyone else know of it?
Trouble is, as Berenyi Peter has pointed out many times and Wallace Broecker would likely now agree, the thermohaline circulation cannot be a heat engine. The thermohaline circulation may not even exist in any form remotely like the fanciful “conveyor belt”.
Climate science can now control ocean currents
…. with wind turbines no less !!!!
How exactly do they KNOW that the current slowed down. Thats pure conjecture.
and somehow are quick to act and alleviate the change, then we have the potential to stop it…
I’m investing heavy in Evinrude/Johnson
Gotta love that Evinrude
If climate scientists think they can somehow control the thermohaline circulation of the oceans, then that makes about as much sense as their ability to control the earth’s volcanic activity. The ego thinks it can do a great many things, but there is a distinct line between reality and fantasy, except for the deluded.
l think Paris and european climate science needs to worry far more about a shut down of the Westerly air flow across europe then it does about a shut down of the North Atlantic drift. l really do think that climate science is barking up the wrong tree . When it try’s to pin major climate change largely down to the ocean currents.
“…to pin major climate change largely down to the ocean currents”
Did I misunderstand? I could see ocean currents causing major climate change, but I just can’t wrap my head around 0.8C over 150 years changing ocean currents enough to matter?
Where l think climate science are getting it wrong is that it believes solely changes to the ocean currents are what causes changes to the weather. l think there wrong, Am convinced that long term changes to the weather are also a major cause of change to the ocean currents. Because is climate science suggesting that the North Atlantic drift shut down during the whole of the ice age.?
“…convinced that long term changes to the weather are also a major cause of change to the ocean currents.”
Chicken & egg? I find the earth’s climate and our Sun very interesting, The less you know, the simpler it appears.
I truly wish that climate science was taken seriously. I feel the next decade will be the decider, but I’m pretty convinced that a few ppm of CO2 is not the driver they’re looking for.
Climate science reminds me of Psychoanalysis. Lots of great sounding theories that make tons of sense logically. But after 100 years of careful study, all will prove worthless.
It would be funny as heck if the did it and it threw the world into catastrophic global warming…
They
The total daily contribution to the surface mass balance from the entire ice sheet (blue line, Gt/day). Bottom: The accumulated surface mass balance from September 1st to now (blue line, Gt) and the season 2011-12 (red) which had very high summer melt in Greenland. For comparison, the mean curve from the period 1990-2013 is shown (dark grey). The same calendar day in each of the 24 years (in the period 1990-2013) will have its own value. These differences from year to year are illustrated by the light grey band. For each calendar day, however, the lowest and highest values of the 24 years have been left out.
http://www.dmi.dk/uploads/tx_dmidatastore/webservice/b/m/s/d/e/accumulatedsmb.png
Ren, I’ve pointed out to you before that without a link to your data you are just jerking our chain. I note that you have very carefully arranged things so that nobody can verify or check your work.
Please jump aboard the 21st century and start citing your data sources. For all we know, you just made this up on your computer.
w.
Willis,
It is from the DMI Greenland Ice Sheet Mass Surface Balance page
http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/
Thanks, ab. As I read it the net Greenland ice sheet accumulation in the worst year (red line, lower plot) was zero … and every year except that the ice sheet has gained mass.
Is that correct?
w.
ren, here’s why sources are important. It turns out that the graph you posted is the result of a model. Not observational results. A model.
Now, I’m not saying that means that the model is wrong, and it’s clearly not useless … but because you didn’t tell folks it was model results and you didn’t provide a link, you’ve unintentionally misled folks.
Bad plan. Folks don’t like that.
w.
Outstanding, the liberals here in Austin surely won’t like these findings…
Yesterdays article on the “Arctic Iris Effect” gives a completely different take on how these events occur. Unless what they’re talking about here is a different circumstance.
It is different. You are correct. A fresh water pulse sufficient to shut off the NA thermohaline circulation must be vast and very abrupt. paleo lake Agassiz suffices; breached ice dams. Nothing in today’s world does. Not even remotely.
And there is no evidence Lake Agassiz did so either. The freshwater shut down is based on the incorrect ocean conveyor belt that suggests changes in buoyancy drives poleward heat transport. That idea is falling apart in most circles except Rhamstorf and Mann’s. As Lozier (2010) wrote, “the conveyor-belt model no longer serves the community well—not because it is a gross oversimplification but because it ignores crucial structure and mechanics of the ocean’s intricate global overturning
“They then compared these findings with previously published ice core data. According to these records, it took a decade or less for temperatures in Greenland to drop by approximately 18 degrees Fahrenheit once the current collapsed”
This would seem to present more of a problem than global warming.
While those geniuses are manipulating ocean currents, I wish they’d go ahead and do something about Earth’s orbital velocity, because I’m getting really tired of leap years.
Plus several shed-loads.
Fortunately my red wine was on the side, not to my lips, so I don’t need a new computer!
Auto
As the world warmed after the last ice age, glaciers melted and diluted northern seawater with freshwater. The resulting change in ocean water density disrupted the current
=======
yep, that works
http://eas2.unl.edu/~tfrank/History%20on%20the%20Rocks/Nebraska%20Geology/Cenozoic/cenozoic%20web/2/Timescale_files/Quaternary%252012.jpg
This map helps to make my point in a earlier post.
They are claiming that the melting of all this ice is what caused the North Atlantic drift to shut down.
So if that is the case, than clearly the North Atlantic drift must have been running during the ice age.
So if the cause of the cold during the ice age was not the shutting down of the North Atlantic drift, then what was.!
Global warming causes global cooling – i.e. they will be blaming any future cooling on global warming, when in fact, global warming and cooling have been cyclically following each other naturally for eons.
Does this map reflect the 400 ft lower sea level that prevailed at the time?
No. It uses modern coastlines.
Yes. There are visible several indicators. One is the outline of Florida. Others are the extra peninsula and oversized channel islands off the coast of Southern California.
The map clearly uses present sea level, not glacial.
During the LGM, the Grand Banks or Newfoundland and Georges Bank off New England were exposed and the Bahamas were mostly a single island.
Across the Atlantic, the English Channel and North Sea were dry land, as was the Rockall Bank in the NE Atlantic, which is now a little rock islet.
The Arctic and Pacific Oceans were separated by Beringia, a vast subcontinent connecting North America and Europe. In SE Asia, Indonesian islands were connected to the mainland.
WHOA!! Even that far back in time there was so much hot air in the DC area that even a glacier couldn’t cross the Potomac. Good to know I’ll be able to get by (as long as I can heat this place.
Yes, and that seawater was depleted in O18 which then evaporated and showed up as a doubly depleted band in the Greenland ice cores. The Younger Dryas was actually a warm period when rapid glacial melting produced a deluge of fresh water in the North Atlantic and a false low temperature indication in the ice cores.
Dang … now there’s an interesting theory. The d18O was from the fresh water and not from an actual temperature drop. Do you have any citations on that one?
w.
Nice try pochas, but the younger dryas was established using palaeobotany, long before anyone measured isotopes.
palaeobotany
==========
lobotomy as practiced by paleontologists
@Willis, Smart Rock
From
http://www.geol.lu.se/personal/seb/Publ%202006-10/Global%20YD%20last%20edition.pdf
“The idea that a sudden fresh-water event triggered the onset of Younger Dryas, such as the diversion of the outlet of Lake Agassiz from the Gulf of Mexico to an eastern outlet with a more or less catastrophic drainage through the St. Lawrence River (Broecker,et al., 1988) and a simultaneous Baltic Ice Lake drainage (Björck,et al., 1996) into the North Sea, is a mechanism that is supported by coupled atmosphere-ocean modeling (Manabe and Stouffer, 1988). A sudden decrease in salinity in areas where NADW normally occurs would have a rapid and disturbing effect on the THC. This would seriously hamper the northwards meridional heat advection, and this model ofexplaining the sudden onset and exceptional length of the Younger Dryas has been widely acknowledged as the most plausible mechanism for the onset of the oscillation”
As stated above, the freshwater blanketing the North Atlantic would be depleted in O18 which would affect the O18 content of subsequent precipitation on Greenland. The sudden freshwater event could only come from a sudden warming. Attendant flooding of the Mississippi Valley and probably large areas of Europe would cause all sorts of confusing botanical stratigraphy.
Did anyone else happen to notice that the image shows very little sea ice in the Arctic during an Ice Age? That seems very interesting to me. I wonder if there is any basis to the drawing or if it’s pure conjecture.
on that theme it is interesting to note temperatures just below 80 degrees north have been cooler for much of the arctic summer than those above . much ice still lingering in hudson bay .
I’m starting a new ocean current rapid response engineering team. I need grants and grant-supported loans to get it started and make it operational. Never mind if it works or not. Want to see my political connections and donor track record?
If they’re taking requests can I have some nice weather (not too hot, not too cold) here in the East Midlands UK for the next 3 weeks? My family are coming over from Seattle and it would be nice to show them round without the bother of coats and umbrellas. Thanks.
After the record-breaking heat wave in Seattle this summer, a nice cool English fall may be quite welcome.
ExSSNcrew
Bangor sub base, WA. Did some MDSU diving ops up there in the 80s. Mostly on the degaussing facilities. Really interesting day up there one time during weaps onload and the jarheads didn’t expect us to be driving by in our dive boats. Fun times.
Oh, it is definitely going to be cool if this forecast is correct :
http://www.telegraph.co.uk/news/weather/11840665/UK-weather-polar-plume-means-icy-conditions-this-weekend.html
If the MET says “There be Sun” Bring an umbrella. If the MET says “It be Dry” wear your Mac’s and Wellies. If the MET says Warm Winter, Buy extra Salt and perhaps a Snow-blower or a couple of good shovels.
Better yet, Bryan, – say –
Tomorrow will be quite like today.
Right as often as the Met Office and Dame Ringo.
Auto
johnbuk , I think we both know that only a climate scientist, or someone who works for the East Midlands Tourist Office, would ever claim it might be too hot in the East Midlands in the next 3 weeks.
So now we have spatial two-point correlation as causation. It’s nice to add another dimension. Or is that one-point with a model on the other end?
Good grief, not that nonsense again.
“…They found that it took more than 550 years for drought conditions to reach their full extent in the region, and about 450 years to return to pre-Younger Dryas levels after the North Atlantic Current began circulating again. The record suggests rainfall was about 25 percent lower than present levels during the cold snap…”
So 50 years of cold weather is a “cold snap?” And a 25% drop in rainfall is “a drought?”
A cold snap, by definition: “a sudden onset of a relatively brief period of cold weather.”
A drought: “a long period of time during which there is very little or no rain.”
These people have lost the ability to speak English. I strongly suspect that the thousand year dry “snap” disappears if you include some error bars.
I love all the ‘coulds’ that the speculative scare mongering reports come up with.
If my sheep started to hunt foxes I ‘could’ look forwards to lambing seasons when I no longer have to worry about foxes taking new-born lambs.
The chances of that are Nil and as my grandmother used to say ‘if wishes were horses then tinkers would ride’.
That for me about sums up ‘climate science’ – a basket-case of wishful thinking.
Sorry – a typo – should have read ‘I love all the ifs and coulds’ ….
I’m quite curious- what physical data show traces of changes in the circulation of ocean currents? Is it the content of sediments? What physical clues would such changes leave behind?
Climate Science the place where hubris and incompetence meet. Can we stop calling it science now? The climate predictions should be right next to the horoscopes. Although horoscopes may be more accurate. Like if Jupter is up in Venus’s business then it’s going to get warmer or something or however the lingo goes.
http://wattsupwiththat.com/2015/09/01/the-arctic-iris-effect-dansgaard-oeschger-events-and-climate-model-shortcomings-lesson-from-climate-past-part-1/
Each and every time I see an article about abrupt climate change I am going to bring it back to the ARCTIC IRIS EFFECT which Jim Steele presented. This is far and away the best explanation for all abrupt sudden climate changes.
“They found that it took more than 550 years for drought conditions to reach their full extent in the region, and about 450 years to return to pre-Younger Dryas levels after the North Atlantic Current began circulating again.”
If this is a cave that depends for its timelines on water dripping from the ceiling then it could have changed very quickly in the Philippines but it may have taken a long time for the aquifer to dry up, which it would do by slowly losing its flow volume. Then when it started raining again it would a long time for the aquifer to recharge and leak again into the cave at ‘full flow’. For this reason I am not sure this proxy has the sharpness of resolution that is available from an ice core.
Is there any indication that this cave has such a sharp resolution and that it is capable of recording the temperature quickly? They state that the deposition of minerals was tracked, which is to say it is a flow-dependent proxy building up thin or thick layers per year or per decade. Have they assumed in their analysis that the flow is from a short, low capacity aquifer? It seems so. Maybe they didn’t think of it. The rainfall may have changed as abruptly as in Greenland and it would still give the pace they report.
Crispin, It the ‘leak’ might also have healed up during the dry period with salts in the shrinking water in the aquifer and it took, possibly a earthquake to refracture it. You know that most of these climate scientists are physicists and not geologists. They even have the temerity to wax strongly on botany. Recall the recent post on planting trees in Urban centres to cool off UHI. There they said the cooling by trees was caused by evapotranspiration, like sweat on human skin, without apparently being aware that part of the coolness in the shade is the endothermic photosynthesis and partly albedo from the canopy (~ 0.2, small but not insignificant).
Surely, their error bars will have taken this into account.
HAHAHAHAHAHAHAHAHAHAHAHAHAHA!!
I still haven’t figured out how deep ocean water that runs zero to three degrees C can warm the air.
It cannot. You can stop figuring on that. Laws of thermodynamics, physics heat flow (flux) and such.
I thought that the causes of the Younger Dryas event were still hotly debated.
As to the claim that there was a big surge of cold water from the NA continent, that too has been proposed, but never demonstrated using real world data. Nor is it proven that a surge of fresh water would stop the N. Atlantic conveyor, or that there would be a dramatic cooling if it did.
MarkW, read up more on YD. Was going to have an essay on YD in the book, but after months of evening/weekend research decided the science was (for me) sufficiently convincingly settled by many papers and counter papers to skip it. That science is pretty well settled.
Mark
Yes its not the North Atlantic drift that keeps europe warm, that’s down to the Westerly air flow across the Atlantic. As shown by the winter of 1962/63 in europe, when blocking shut off the mild westerly winds.