Research into ancient global cooling published in Science

Jun 03, 2011

Thirty-eight million years ago, tropical jungles thrived in what are now the cornfields of the American Midwest and furry marsupials wandered temperate forests in what is now the frozen Antarctic. The temperature differences of that era, known as the late Eocene, between the equator and Antarctica were only half of what they are today. A debate has long been raging in the scientific community on what changes in our global climate system led to such a major shift from the more tropical, greenhouse climate of the Eocene to the modern and much cooler climates of today.

New research published in the journal Science, led by Rensselaer scientist Miriam Katz, is providing some of the strongest evidence to date that the Antarctic Circumpolar Current (ACC) played a key role in the major shift in the global climate that began approximately 38 million years ago. The research provides the first evidence that early ACC formation played a vital role in the formation of the modern ocean structure.

“What we have found is that the evolution of the Antarctic Circumpolar Current influenced global ocean circulation much earlier than previous studies have shown,” said Katz, assistant professor of earth and environmental science. “This finding is particularly significant because it places the impact of initial shallow ACC circulation in the same interval when the climate began its long-term shift to cooler temperatures.”

There has been a debate over the past 40 years on what role the Antarctic Circumpolar Current had in the underlying cooling trend on Earth. Previous research has placed the development of the deep ACC (greater than 2,000 meters water depth) in the late Oligocene (approximately 23-25 million years ago). This is well after the global cooling pattern had been established. With this research, Katz and her colleagues used information from ocean sediments to place the global impact of the ACC to approximately 30 million years ago, when it was still just a shallow current.

Oceans and global temperatures are closely linked. Warmer ocean waters result in warmer air temperatures and vice versa. In the more tropical environs of the , ocean circulation was much weaker and currents were more diffuse. As a result, heat was more evenly distributed around the world. This resulted in fairly mild oceans and temperatures worldwide, according to Katz. Today, ocean temperatures vary considerably and redistribute warm and cold water around the globe in significant ways.

“As the global ocean currents were formed and strengthened, the redistribution of heat likely played a significant role in the overall cooling of the Earth,” Katz said.

And no current is more significant than the ACC. Often referred to as the “Mixmaster” of the ocean, the ACC thermally isolates Antarctica by preventing warm surface waters from subtropical gyres to pass through its current. The ACC instead redirects some of that warm surface water back up toward the North Atlantic, creating the Antarctic Intermediate Water. This blocking of heat enabled the formation and preservation of the Antarctic ice sheets, according to Katz. And it is this circumpolar circulation that Katz’s research concludes was responsible for the development of our modern four-layer current and heat distribution system.

Katz points out that the larger cooling trend addressed in the paper has been punctuated by many short, but often significant, episodes of global warming. Such ancient episodes of warming are another significant aspect of her research program, and play an important role in understanding the modern warming of the climate occurring on the planet.

“By reconstructing the climates of the past, we can provide a science-based means to explore or predict possible system responses to the current climate change,” Katz said.

Explore further: Suomi NPP satellite spots birth of Tropical Cyclone Kate

More information: “Impact of Antarctic Circumpolar Current development on late Paleogene ocean structure,” Science DOI: 10.1126/science.1202122

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User comments : 17

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Bigblumpkin36
3 / 5 (2) Jun 03, 2011
So if the ice caps melt the earth go into a cooling faze or will the oceans currents shift or both?
omatumr
1.4 / 5 (11) Jun 03, 2011
Thirty-eight million years ago, tropical jungles thrived in what are now the cornfields of the American Midwest . . .


Miriam Katz and Science are to be congratulated for acknowledging that the past climate offers "a science-based means to explore or predict possible system responses to the current climate change".

That kind of information [1-3] was ignored by Al Gore and the UN's IPCC in promoting the story of CO2-induced global warming.

1. Suns motion and sunspots, Astron. J., 1965, 70, 193-200 (1965)

2. Prolonged minima and the 179-yr cycle of the solar inertial motion, Solar Physics110, 191-220 (1987)

3. "Super-fluidity in the solar interior: Implications for solar eruptions and climate"
Journal of Fusion Energy 21, 193-198 (2002)

http://arxiv.org/.../0501441

4. "Earth's Heat Source - The Sun", Energy & Environment 20, 131-144 (2009)

http://arxiv.org/pdf/0905.0704

With kind regards,
Oliver K. Manuel

Ethelred
4 / 5 (8) Jun 03, 2011
Spam spam spam spam
Spam spam spam spam
Spammity spam Cranking out spam

The Sun disagrees with you.

It does NOT have a rigid iron surface as that is impossible for a plasma of any composition. That you refuse to see this is not a sign of sanity as your position is utterly indefensible.

The Sun does not have a neutron star in it as the smallest neutron star possible is more massive than the Sun.

Any hydrogen gas on a white dwarf or a neutron star must eventually go BANG on that multi billion gravity surface.

There is no evidence for neutron repulsion. YOUR students table does not in way show that anything other than the Pauli Exclusion principle is involved.

None of those students are supporting on this so clearly they don't agree with your idea either.

There is ONE person that supports Oliver.

An anti-global warming crank.

Ethelred
ted208
1.7 / 5 (11) Jun 04, 2011
Ethelred
Take your meds and stop eating Spam spam spam spam, its making you cranky. Read the Article and Oliver K. Manuel comments and links then come back with something intelligent say. Try to see through the fog created by the CAGW gangsters try some skeptic websites like Watts-up and you might find a glimpse of the real world and the ever change natural climate. Also explore the Earths climate history and how its affected every great civilization through warm and cold periods then come back and say this is unprecedented warming!
Gilbert
4 / 5 (8) Jun 04, 2011
teddy

I beleive you will find if you also research the other side of the fence you will find a bit of evidence supporting that too.

perhaps the mistake you are making is that you are thinking that they are saying that the current global climate is
"unprecedented warming". whereas evidence.. from real observations.. is pointing to a trend that we are at the start of. not a current huge crisis.. but a future crisis.
Now also you probably live in the United States, a country situated in such a place that the observations have not changed much, I hope however, that you realise that you live in a world much bigger than your country
MarkyMark
not rated yet Jun 04, 2011
Spam spam spam spam
Spam spam spam spam
Spammity spam Cranking out spam

The Sun disagrees with you.

It does NOT have a rigid iron surface as that is impossible for a plasma of any composition. That you refuse to see this is not a sign of sanity as your position is utterly indefensible.

The Sun does not have a neutron star in it as the smallest neutron star possible is more massive than the Sun.

Any hydrogen gas on a white dwarf or a neutron star must eventually go BANG on that multi billion gravity surface.

There is no evidence for neutron repulsion. YOUR students table does not in way show that anything other than the Pauli Exclusion principle is involved.

None of those students are supporting on this so clearly they don't agree with your idea either.

There is ONE person that supports Oliver.

An anti-global warming crank.

Ethelred

Instead of responding to that cranks (with a very dodgy name) spam why dont you just press the Report Abuse link?
PinkElephant
3.7 / 5 (3) Jun 04, 2011
@Ethelred,

You're generally correct, however this:
the smallest neutron star possible is more massive than the Sun
Is not necessarily true, at least in theory. For instance:

http://www.mendel...on-star/

The Chandrasekhar limit of 1.4 solar masses refers to the pre-collapse mass of a stellar precursor. In the collapse, a neutronium core is formed, but depending on how asymmetric and/or violent the collapse is, the amount of material ejected vs. trapped in the remnant may vary a lot.

Of course in practice, I'm not aware of any neutron star observations where the remnant is actually lighter than the Sun. So maybe there are constraints on processes that create neutron stars, which prevent formation of neutron "dwarfs".

And even if such dwarfs were to exist, at a minimum they must be so rare that modern astronomy hasn't managed to detect them yet despite the tremendous quantity of data already obtained.
Ethelred
4.5 / 5 (8) Jun 04, 2011
And even if such dwarfs were to exist,
They would still have a surface gravity of over a billion gravities and any large volume of hydrogen would fuse explosively long before forming anything resembling the photosphere.

Teddy
I have read Oliver's crap. How about YOU read it. I was pointing out that ONLY a Global Warming denier backs him. That's it. ONE person that happens to be engaged in crankery themselves.

Now it possible to have a fantasy about global warming without being a crank but the South African that is backing Oliver IS a crank.

No we don't know everything about what causes global warming BUT at present the ice is melting and frankly I live fairly close to sea level. It is stupid to not try to find out why the ice is melting even if we can't do anything about it.

Oliver is a Crank. Like all science cranks he attacks science wherever he can because he is under the delusion that somehow that will make his nonsense real.

Ethelred
Shootist
1.8 / 5 (5) Jun 04, 2011
Ethel

You do not know Dr. Manuel's motivation.

You may disagree with him, but don't become Sagan to his Velikovsky. Velikovshy might have been a crank, but Sagan was an ass.

http://www.jerryp...vsky.htm

omatumr
1 / 5 (6) Jun 05, 2011
This interview with Dr. Ivanka Charvátová from the Geophysical Institute of the Czech Academy of Sciences (Prague) shows that other scientists also disagree with the global warming story promoted by Al Gore, the UN's IPCC, and an army of government-paid climatologists:

www.klimaskeptik....rom-gfu/

Gravitational interaction of orbiting planets with the Suns central neutron star apparently jerk it around inside the glowing ball of waste products (H/He-rich photosphere) like a yo-yo on a string.

The Sun is not a giant ball of Hydrogen, but it and other star generate and discard tons of Hydrogen each year from neutron-decay: Neutron => Hydrogen

Gilbert
5 / 5 (1) Jun 05, 2011
yes omatumr,
we agree that Al gore's message is exaggerated, however don't you think it's better he use this message on those less educated to counter all the corporate propaganda out there. Even if you are right, don't you think it is still worthwhile to have the industries that are very negligent pull up and be responsible for a myriad or other reasons, not just for "lowering carbon", but for human rights, natural habitat protection, chemical waste reduction, huge increases in efficiency, renewable energy, job creation and a whole lot more?

Isn't it worth letting the plebs believe in exaggerated climate models for all that? even if its not happening?
Ethelred
5 / 5 (5) Jun 05, 2011
You do not know Dr. Manuel's motivation
Oliver IS a Crank. And worse. His constant attacks on science are not likely to be grounded in anything but his ideas being rejected by rational scientists. He is clearly pretty bitter about it and frankly I don't care one wit how the well deserved rejection effects him.

It is quite possible, even likely, that Oliver actually believes the crap he is pushing about Global Warming and the many scientists that he insults on a weekly if not daily basis with his attacks on their honesty and competence. The man lived a lie for all his life. He has no business calling anyone dishonest. His competence scientifically is nonexistent outside a very narrow field and he is outside of it. He isn't even remotely competent at all in either of the fields he posts on. Which is the idiocy that is the Iron Sun and Global Warming where he is denier and just as unwilling to discuss GW rationally as he is unwilling to discuss Neutron Repulsion rationally.>>
Ethelred
5 / 5 (5) Jun 05, 2011
I do not need to know his motivations perfectly to know that he is not competent in either area. If he is right on GW it is purely an accident. Yes the Sun is variable. So is the CO2 level. But HE thinks showing the Sun is variable will somehow prove it has a Neutron Star in it and rigid iron surface and that neutron repulsion will become something other than the Pauli Exclusion Principle. If you think this not, at the very least, a major part of the motivation behind his behavior you are not being realistic.

Velikovshy might have been a crank, but Sagan was an ass.
Velikovksy was an ass. Sagan was correct even if he was arrogant and few scientists are willing to debate Cranks and religious fanatics at all. Sagan was correct to take him on. If Pournelle has a problem with that its HIS problem and I don't agree with him on it. Neither Sagan or Pournelle were/are perfect people. BOTH were/are vastly superior in honesty, decency and competence to Oliver. Heck so was Velikovsky.>>
Ethelred
5 / 5 (7) Jun 05, 2011
Now if you have a problem with the Global Warming theory feel free to discuss it with me. Oliver is not going to do that rationally with anyone. The only thing I go on with GW is the ice is melting and a LOT of cities are port cities. IF the Sun was the major cause of the heating that is observed it should have an effect rather similar to the climate prior to the Little Ice Age, tropical and mid latitude warming with minimal melting at the highest latitudes. If CO2 is having a significant effect it should have more effect at the poles. This seems to be what is happening. It would be cool if the Brits were able to have vineyards again but if most of the port cities go under those vineyards are just not going be enough compensation.

Ethelred
Ethelred
5 / 5 (3) Jun 05, 2011
shows that other scientists also disagree with the global warming story
Certainly there are scientists that do. I think even Gore knows that. Has to by now. Then again even Bush came to the conclusion that GW is occurring.

army of government-paid climatologists
Ivanka Charvátová is also government paid.

Gravitational interaction of orbiting planets with the Suns central neutron star
Can't happen since there is no neutron star in the Sun. Now the churning idea is reasonable BUT since the heat reaching the surface of the Sun come from reactions that took place a million years ago, according to theory that actually follows known physics, it seems that there might be a bit of lag between the churning and the heat released from the photosphere.

waste products (H/He-rich photosphere)
She didn't say that despite you spamming her. She mentioned you but not one word about a neutron star.>>
Ethelred
5 / 5 (3) Jun 05, 2011
Wolf Minimum (1270-1350) 160 - 170
Spörer Minimum (~1430-1520) 190 - 190
Maunder Minimum (~1620-1710) 170 - 130
Dalton Minimum (~1790-1840) ? why not already happening?

160+170+190+190+170+130 = 1010 / 6 = 168

The 130 is a bit off from the rest without that the average is 176

Beginnings 520 / 3 = 173

Either way its close but not the the same as the 179 in the interview.

1790 + 179 = 1969 average
1790 + 160 = 1950 shortest beginning to beginning
1790 + 130 = 1920 shortest ending to ending
1790 + 190 = 1980 longest interval of any kind

So where is that minimum? The latest solar minimum did go a couple of years more than normal BUT that just ended and we still don't have new minimum UNLESS there is something causing the temperature to be high anyway. CO2 perhaps?

However a long term minimum should have few if any sunspots for decades and that isn't happening at the moment.>>
Ethelred
5 / 5 (3) Jun 05, 2011
And where did this thing come from in the interview?
We agree that in the first half of the 21st century the solar activity might be lower and even the temperatures might go down.
That doesn't follow from her numbers. Her numbers produce the mid to late 20th century for a new minimum. Funny how that got ignored. Then again the interviewer didn't want to find errors since the site is a denial site.

Its an interesting concept and I suspect it is at least partly true HOWEVER the timing of the minimums have a problem with the present lack of a minimum which should have started 30 or more years ago.

Ethelred

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