Ancient warming greened Antarctica, research finds

Jun 17, 2012
This artist's rendition created from a photograph of Antarctica shows what Antarctica possibly looked like during the middle Miocene epoch, based on pollen fossil data. Image credit: NASA/JPL-Caltech/Dr. Philip Bart, LSU

(Phys.org) -- A new university-led study with NASA participation finds ancient Antarctica was much warmer and wetter than previously suspected. The climate was suitable to support substantial vegetation -- including stunted trees -- along the edges of the frozen continent.

The team of scientists involved in the study, published online June 17 in Nature Geoscience, was led by Sarah J. Feakins of the University of Southern California in Los Angeles, and included researchers from NASA's Jet Propulsion Laboratory in Pasadena, Calif., and Louisiana State University in Baton Rouge.

By examining wax remnants in sediment core samples taken from beneath the Ross Ice Shelf, the research team found along the Antarctic coast 15 to 20 million years ago were 20 degrees Fahrenheit (11 degrees Celsius) warmer than today, with temperatures reaching as high as 45 degrees Fahrenheit (7 degrees Celsius). Precipitation levels also were found to be several times higher than today.

"The ultimate goal of the study was to better understand what the future of climate change may look like," said Feakins, an assistant professor of Earth sciences at the USC Dornsife College of Letters, Arts and Sciences. "Just as history has a lot to teach us about the future, so does past climate. This record shows us how much warmer and wetter it can get around the as the heats up. This is some of the first evidence of just how much warmer it was."

Scientists began to suspect that high-latitude temperatures during the middle Miocene epoch were warmer than previously believed when co-author Sophie Warny, assistant professor at LSU, discovered large quantities of pollen and algae in taken around Antarctica. Fossils of plant life in Antarctica are difficult to come by because the movement of the massive ice sheets covering the landmass grinds and scrapes away the evidence.

Rendering of drilling operations during the ANDRILL campaign in Southern McMurdo Sound, Antarctica, October - December 2007. Image credit: University of Nebraska-Lincoln

"Marine sediment cores are ideal to look for clues of past vegetation, as the fossils deposited are protected from ice sheet advances, but these are technically very difficult to acquire in the Antarctic and require international collaboration," said Warny.

Tipped off by the tiny pollen samples, Feakins opted to look at the remnants of leaf wax taken from sediment cores for clues. Leaf wax acts as a record of climate change by documenting the hydrogen isotope ratios of the water the plant took up while it was alive.

"Ice cores can only go back about one million years," Feakins said. "Sediment cores allow us to go into 'deep time.'"

Based upon a model originally developed to analyze hydrogen isotope ratios in atmospheric water vapor data from NASA's Aura spacecraft, co-author and JPL scientist Jung-Eun Lee created experiments to find out just how much warmer and wetter climate may have been.

"When the planet heats up, the biggest changes are seen toward the poles," Lee said. "The southward movement of rain bands associated with a warmer climate in the high-latitude southern hemisphere made the margins of Antarctica less like a polar desert, and more like present-day Iceland."

The peak of this Antarctic greening occurred during the middle Miocene period, between 16.4 and 15.7 million years ago. This was well after the age of the dinosaurs, which became extinct 64 million years ago. During the Miocene epoch, mostly modern-looking animals roamed Earth, such as three-toed horses, deer, camel and various species of apes. Modern humans did not appear until 200,000 years ago.

Warm conditions during the middle Miocene are thought to be associated with carbon dioxide levels of around 400 to 600 parts per million (ppm). In 2012, carbon dioxide levels have climbed to 393 ppm, the highest they've been in the past several million years. At the current rate of increase, atmospheric carbon dioxide levels are on track to reach middle Miocene levels by the end of this century.

High carbon dioxide levels during the middle have been documented in other studies through multiple lines of evidence, including the number of microscopic pores on the surface of plant leaves and geochemical evidence from soils and marine organisms. While none of these 'proxies' is as reliable as the bubbles of gas trapped in ice cores, they are the best evidence available this far back in time. While scientists do not yet know precisely why carbon dioxide was at these levels during the middle Miocene, high , together with the global warmth documented from many parts of the world and now also from the Antarctic region, appear to coincide during this period in Earth's history.

Explore further: Hurricane Edouard right environment for drone test (Update)

More information: Hydrologic cycling over Antarctica during the middle Miocene warming, DOI: 10.1038/ngeo1498

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po6ert
2.6 / 5 (25) Jun 17, 2012
you mean to say that the world didn't come to an end because of high levels of co2. climate chanfes contiually. when will we learn the lesson of canute the dane?
Sonhouse
3.4 / 5 (24) Jun 17, 2012
you mean to say that the world didn't come to an end because of high levels of co2. climate chanfes contiually. when will we learn the lesson of canute the dane?


Tell me one person who ever said the WORLD would come to an end with climate change?

It's not the planet which has the problem, it's PEOPLE you asswipe.
MikPetter
3.4 / 5 (15) Jun 17, 2012
Worth noting sea level was at least 50m higher at this time. Both extremes of climate change, hot and cold have profound changes on the global ecology and biogeochemical cycles. The difference this time is that we are choosing the path
Jonseer
3.4 / 5 (19) Jun 17, 2012
you mean to say that the world didn't come to an end because of high levels of co2. climate chanfes contiually. when will we learn the lesson of canute the dane?


Spoken like a true know nothing about global warming.

NO THEORY, NOBODY claims the world will end due to global climate change.

The threat of climate change induced by our actions is to HUMANITY, not the planet.

All it says is it is getting warmer MUCH faster than it would otherwise thanks to our influences, and too fast for humanity to adapt without immediate, extreme measures like moving whole cities to higher land, and allowing wholesale population migrations from threatened lowlands to safe higher land.

Because we are basically doing nothing, HUMANS could likely suffer a global catastrophe that could set civilization back 1000s of years.

The Earth however will do fine, and should the worst come to pass go on as always and not even notice the end of humankind.
Vendicar_Decarian
3 / 5 (18) Jun 17, 2012
The following graphic summs things up pretty well.

http://www.global..._Rev.png

At no time during the Miocene was the temperature rise as rapid and disastrous as today.
Osiris1
1.2 / 5 (9) Jun 17, 2012
Yep, now comes the great race for Antarctic territory. It WILL be a race dominated by great military powers with China leading and the rest following, not because they want to, but because they HAVE to or be relegated to forever third world status or worse.....invasion, domination, and partition and maybe forced resettlement of vast numbers of immigrants displacing the local of the weak present residents by stronger and more fit foreigners....law of the jungle survival of the fittest and not the nicest. Nice guys and 'politically correct' guys will finish last. Dead last!
kivahut
2.8 / 5 (9) Jun 17, 2012
Yay! Antarctica sucks right now. Some lovely green around the edges would make it much better.
R_R
1 / 5 (19) Jun 17, 2012
More utterly useless science due to the fact that pole shift 12,000 years ago has been systematicly covered up. It was warm on this half of Antartica 15 million years ago right up to 15 thousand years ago because the previous south pole was 2000 miles closer to Australia. All ice sheets here are under 12,000 years old.
Vendicar_Decarian
3.9 / 5 (14) Jun 18, 2012
Another devo American living in LA-LA-Land...

"More utterly useless science due to the fact that pole shift 12,000 years ago has been systematicly covered up." - RR

jscroft
1.5 / 5 (16) Jun 18, 2012
What fossil fuels were those dinosaurs burning, I wonder?
ROBTHEGOB
2.1 / 5 (11) Jun 18, 2012
iscroft: the dinosaurs were probably driving Cadillac Escalade's.
Noumenon
2.6 / 5 (15) Jun 18, 2012
[thanks to our influences, ] too fast for humanity to adapt without immediate, extreme measures like moving whole cities to higher land, and allowing wholesale population migrations from threatened lowlands to safe higher land.

Because we are basically doing nothing, HUMANS could likely suffer a global catastrophe that could set civilization back 1000s of years.


This type of over hyped bedwetting hysteria is scientifically unfounded wide-eyed speculation,... and it is what is rejected by humanity, and is the reason such emmergency action is NOT being taken right now.

There must be some actual effect for humanity to react to, because it is not in anyone's best interest to adjust based on speculative theory. It is costly to "immediately" move "whole cities to higher land", and quit ridiculous and most certainly unnecessary all at one time. Climate change (which is natural) occurs gradually,... and any migration will like wise be gradual and barely noticable over generations.
rubberman
3.2 / 5 (13) Jun 18, 2012
"There must be some actual effect for humanity to react to, "

You mean something that actually effects a large swath of humanity right? Because of my job I have had to react to the changes happening in the arctic for a few years now. I am not going to post a bunch of links to pictures of roads and buildings in northern communities that have sank into melting permafrost...but I could.
aroc91
3 / 5 (8) Jun 18, 2012
The following graphic summs things up pretty well.

http://www.global..._Rev.png

At no time during the Miocene was the temperature rise as rapid and disastrous as today.


You can't determine that at all from that graph. That graph has a 10 million year scale. There's clearly no way to see the ~100 year scale we deal with today.
rubberman
3.3 / 5 (14) Jun 18, 2012
The following graphic summs things up pretty well.

http://www.global..._Rev.png

At no time during the Miocene was the temperature rise as rapid and disastrous as today.


You can't determine that at all from that graph. That graph has a 10 million year scale. There's clearly no way to see the ~100 year scale we deal with today.


Fortunately there are ALOT of sources of info. regarding the numerous warming and cooling events of the last 250 million years...none of which show anything close to the current rate of warming. The rate of PETM warming .7 degrees C per 1000 years, it took 10000 years to warm up 7 degrees. At this rate it will be less than 1000 years this time. "Some like it hot" by Robert Palmer springs to mind.....
timothyearl_spicer
1.6 / 5 (7) Jun 18, 2012
Has anyone considered if the earth was off tilted by a comet how long it would take to rebalanced? or even that of the poles flipping? (by the way, even then, has anyone considered what sets off the poles flipping, like solar activities?). when they drilled for the information, what was the added info of what it was like before then by an added half million years?
Noumenon
2.5 / 5 (13) Jun 18, 2012
"There must be some actual effect for humanity to react to, "

You mean something that actually effects a large swath of humanity right? Because of my job I have had to react to the changes happening in the arctic for a few years now. I am not going to post a bunch of links to pictures of roads and buildings in northern communities that have sank into melting permafrost...but I could.


You're reacting right? If you never heard of AGW, you would still likewise react to existing circumstances.

Humanity, in large mass, is not going to suddenly discover at 8:20pm on a Tuesday, environmental effects, that immediately change their life styles.

If anything occurs at all, it will do so very gradually, over generations of time,.. so that most may not even be conscious of it, apart from propaganda by leftist charletons abusing the issue.
Noumenon
2.5 / 5 (13) Jun 18, 2012
You can't determine that at all from that graph. That graph has a 10 million year scale. There's clearly no way to see the ~100 year scale we deal with today.
....there are ALOT of sources of info. regarding the numerous warming and cooling events of the last 250 million years...none of which show anything close to the current rate of warming.


That's because they CAN'T show such a rate of increase, as there is no such sub-century resolution in the data, ...to show that it never occurred at current rates, nor to show how the global environment responds.
rubberman
3.2 / 5 (13) Jun 18, 2012


That's because they CAN'T show such a rate of increase, as there is no such sub-century resolution in the data, ...to show that it never occurred at current rates, nor to show how the global environment responds.


This is true. However, since the PETm is regarded as the largest and longest lasting warming event since the dinosaur extinction it has been studied with enough detail to know it's rate of warming (mentioned above)and it's duration (250,000 years). Therefore, regarding the current rate of warming, if it continues, it is geologically unprecedented.
Noumenon
2.3 / 5 (12) Jun 18, 2012
Therefore, regarding the current rate of warming, if it continues, it is geologically unprecedented.


This is an unsubstantiated claim, or at least is speculative.

The above point was, that there is no sub-century resolution in the data, to say that warming never occurred at the current rate in the past, in a sub-century time period.

The data is just averaged over thousands of years (the rate), which is useless in extrapolating in such short time periods. We are lost in short time period cycles.
NotParker
2.2 / 5 (13) Jun 18, 2012


That's because they CAN'T show such a rate of increase, as there is no such sub-century resolution in the data, ...to show that it never occurred at current rates, nor to show how the global environment responds.


This is true. However, since the PETm is regarded as the largest and longest lasting warming event since the dinosaur extinction it has been studied with enough detail to know it's rate of warming (mentioned above)and it's duration (250,000 years). Therefore, regarding the current rate of warming, if it continues, it is geologically unprecedented.


The last interglacial, the Eemian, warmed by about 10C.

http://www.ferdin...ian.html

Hippos roamed the UK and Germany.

The Eemian ended. The ice sheets returned. The same will happen with the Holocene.
R_R
1 / 5 (11) Jun 18, 2012
but analysis of a 30-by-50-mile rise in the ice sheet near the Ross Ice Shelf called Siple Dome suggests that this feature was not overrun by a massive ice sheet in the past.....Another line of evidence that throws the ice sheet's ancient bulk into question is the discovery that the ice sheet was still growing as recently as 8,000 years ago. The reconstruction assumed that the ice sheet reached its maximum growth 20,000 years ago and has only been in retreat since then.
R_R
1 / 5 (11) Jun 18, 2012
So we are told that giant ice fields covered the poles during the so called ice ages but in west antarctica not one shred of evidence exists that the ice fields were ever larger then today, no eratic boulders higher up the hills, no glacial end piles farther out then today. But evidence that contridicts is merely ignored or ridiculed by brainwashed savants like Vendicar.
Vendicar_Decarian
3.2 / 5 (9) Jun 18, 2012
Iscroft seems to be burning the stupidity candle at both ends.

"What fossil fuels were those dinosaurs burning, I wonder?" - IscrofTard
schwarz
3.7 / 5 (7) Jun 19, 2012
"
This type of over hyped bedwetting hysteria is scientifically unfounded wide-eyed speculation,."

Words of a complacent, ignorant person who has no idea where his last meal came from or what it took to produce it. When climate change starts to compromise the productivity of the world's breadbasket regions, you will see just how wrong you are.
Jbagby2012
1.7 / 5 (3) Jun 19, 2012
The magnetic pole shift is well documented. I wonder, however, if in addition to the magnetic pole shift the axial precession of the poles changes significantly over millions of years. If so, that could have a significant impact on the climate of Antarctica in the Miocene.
R_R
1 / 5 (8) Jun 19, 2012
Ya I get it, arn't you clever savant boy. Its clever fellows like you that keep us unprepared for the very real threat of impact. Hope the next one lands on your head.
R_R
1.6 / 5 (10) Jun 19, 2012
PS Folks, the reason there is no evidence of a larger ice cap in west antarctica during the so called ice ages is the same reason there is no evidence that ice existed in sibera and north alaska at this time, because there was no ice age! There was ploe shift! Dont follow the piper.
rubberman
3.5 / 5 (8) Jun 20, 2012
R_R - You are talking about true polar wander, not a "pole shift". What you are proposing happens naturally by approximately 1 degree every million years. A "shift" at the rate you speak of would be blatently evidenced by a large number of geologic and environmental markers and would require a major impact or spectacular celestial event in order to cause it. Jbag is correct. Magnetic pole shift has no verifiable effect on climate.

http://en.wikiped...noxes.29
NotParker
1.7 / 5 (6) Jun 20, 2012
R_R - You are talking about true polar wander, not a "pole shift". What you are proposing happens naturally by approximately 1 degree every million years. A "shift" at the rate you speak of would be blatently evidenced by a large number of geologic and environmental markers and would require a major impact or spectacular celestial event in order to cause it. Jbag is correct. Magnetic pole shift has no verifiable effect on climate.

http://en.wikiped...noxes.29


"The time spans of chrons are randomly distributed with most being between 0.1 and 1 million years with an average of 450,000 years. Most reversals are estimated to take between 1,000 and 10,000 years. "

http://en.wikiped...reversal

1,000 years.
R_R
1.3 / 5 (12) Jun 21, 2012
Hi Rubberman, the reason a huge ice cap covered north america 12000 years ago and then simply up and vanished was due to sudden pole shift, I can tell u the pole moved 28 degrees from hudson bay and I can more then back that up against anyone walking this planet. Unfotunately its like the human race just cant go there.
barakn
4 / 5 (8) Jun 23, 2012
R_R, multiple people (thermodynamics in http://phys.org/n...ion.html ) tackled your theory that the Earth's rotation was reversed by an impact at Hudson bay. In particular I showed you how to calculate the energy necessary and thus the size of the impactor. I fudged the calculation in your favor everywhere I could by optimizing the impact angle, overestimating the efficiency in which impactor momentum would be transferred to the Earth's angular momentum, overestimating impactor density to minimize its width, and choosing an impactor speed at the high end of the range to maximize the kinetic energy to mass ratio. I ended up with an asteroid too big to fit in the hole. It also unleashed enough energy to sterilize the planet's surface. You had every opportunity to point out mistakes in my reasoning and to provide more detailed calculations.
barakn
4.5 / 5 (8) Jun 23, 2012
What did you do instead? Called me a clod, suggested other people get their money back on their physics degrees, did just about everything EXCEPT prove the physics wrong. Until you can prove your scenario is physically possible, you're just smoking crack along with all the other crackpots.
Vendicar_Decarian
3.7 / 5 (6) Jun 23, 2012
ParkerTard's own reference graphic shows how CO2 rose during that period to create most of the warming experienced.

"The last interglacial, the Eemian, warmed by about 10C." - ParkerTard

Poor Mentally diseased ParkerTard. Or Sunshinehours1 as he is known on other systems.

Vendicar_Decarian
3.7 / 5 (6) Jun 23, 2012
I am always astonished that mental midgets like R-R publicly pontificate on such matters, oblivious to how absolutely impossible their crack pot ideas are.

They have no concept of the scales of things. No clue as to how to estimate them. No capacity to evaluate them. As a result they just jabber anti-science nonsense.

"the reason a huge ice cap covered north america 12000 years ago and then simply up and vanished was due to sudden pole shift" - R-R
Vendicar_Decarian
3.7 / 5 (3) Jun 23, 2012
26,000 years for one cycle, 2,000 years for one age.

Next age = Aquarius.

Current Age = Pisces

"axial precession of the poles changes significantly over millions of years." - Jbag
R_R
1.4 / 5 (10) Jun 24, 2012
Barakn, your not interested in finding the truth. I gave u scenarios which u ignored, typical of your brainwashed kind, now get back to your calculater and figure how much ur university owes u.
R_R
1.4 / 5 (10) Jun 24, 2012
Vendicar, not once have u asked me a question about my work because u hav a closed mind, so stay stuck in first gear like the rest of your brainwashed kind.
NotParker
1.7 / 5 (6) Jun 24, 2012
The last interglacial, the Eemian, warmed by about 10C.

And those with an IQ over 100 can see that temperature rise came first, causing CO2 to outgas from the oceans.

Blue line goes up (temperature), pink (CO2) follows about 800 years later.

And yellow (methane) follows about 1200 years later.
http://www.ferdin...ian.html
R_R
1.4 / 5 (10) Jun 24, 2012
The previous pole was centered at hudson bay for millions of years before pole shift 10500 BC, marked very obviously by the canadian shield, home of a normal sized ice cap. Temp fluctuations would have expanded and contracted it some but never was there no ice cap there. I defy any of u genius phds to provide evidence north america was ice free during the so called Eemian interglacial. Put up or shut up. Ill show u what garbage ur science is!
R_R
1.4 / 5 (10) Jun 24, 2012
PS I will make it real easy for u genious'. There was no ice cap in Europe previous to 10500 BC. If u rather, show some of that boat load of evidence u have Europe was covered by ice during ur imajinary ice age.
Vendicar_Decarian
3 / 5 (6) Jun 24, 2012
Since when have delusions been "work"?

"not once have u asked me a question about my work" - R_R
R_R
1.5 / 5 (8) Jun 24, 2012
Ya thats what I thought. Always the same.
Vendicar_Decarian
3.4 / 5 (5) Jun 24, 2012
I will ask again...

Since when have your delusions been "work"?
R_R
1.4 / 5 (9) Jun 24, 2012
I will answer again....

You keep repeating there was an ice age as u have been told but u cant produce evidence to back that up. Thats because there is no evidence. A porrot can repeat what it is told as well.
Vendicar_Decarian
3.4 / 5 (5) Jun 24, 2012
I will ask again...

Since when have your delusions been "work"?

Does mental illness run in your family as it does in ParkerTard's family?
Modernmystic
1.6 / 5 (7) Jun 29, 2012
you mean to say that the world didn't come to an end because of high levels of co2. climate chanfes contiually. when will we learn the lesson of canute the dane?


Tell me one person who ever said the WORLD would come to an end with climate change?

It's not the planet which has the problem, it's PEOPLE you asswipe.


http://wattsupwit...nhinged/

...
barakn
4.3 / 5 (6) Jun 29, 2012
Barakn, your not interested in finding the truth. I gave u scenarios which u ignored, typical of your brainwashed kind, now get back to your calculater and figure how much ur university owes u.

Translation: My name is R_R, and I don't have enough of an education to determine whether my own theory passes a physics smell test, but rather than seeking help from those around me, I'm just going to make fun of their educations.
TheGhostofOtto1923
3.9 / 5 (18) Jul 01, 2012
Tell me one person who ever said the WORLD would come to an end with climate change?
-Close enough?

"man-made events could also threaten the survival of intelligent life on Earth, like catastrophic global warming"
http://en.wikiped...et_Earth

-I think this is usually what 'end of world' is referring to-
TheGhostofOtto1923
3.8 / 5 (17) Jul 01, 2012
"It has been suggested that runaway global warming (runaway climate change) might cause the climate on Earth to become like Venus, which would make it uninhabitable. In less extreme scenarios it could cause the end of civilization, as we know it."
PussyCat_Eyes
1 / 5 (5) Jul 01, 2012

Tell me one person who ever said the WORLD would come to an end with climate change?

It's not the planet which has the problem, it's PEOPLE you asswipe.


http://wattsupwit...nhinged/

... - ModernMystic

Yeppers....people in high places are getting unhinged, but people like Vendicar_De Idiot and his friend, TheGhostofOtto1923 and his Nazi loving sock puppet, TheGhostofOtto1932, have been unhinged for a long time already.

It kind of reminds me of Hank Johnson...you remember him? The Congressman from Georgia said ""My fear is that the whole island (Guam) will become so overly populated that it will tip over and capsize," Johnson said."
Later on, Johnson backpedaled, saying that he was joking. The person he had said it to was Admiral Robert Willard, head of the U.S. Pacific Fleet.
http://www.cbsnew...544.html
Vendicar_Decarian
5 / 5 (3) Jul 02, 2012
Johnson is clearly mentally ill.

http://www.youtub...czIgVXjg

You have to wonder how American's can be so stupid to vote such a man into a position of power.

This is not a failure of Johnson. It is a failure of the American People.

""My fear is that the whole island (Guam) will become so overly populated that it will tip over and capsize," Johnson said." - PussyCatLies
Vendicar_Decarian
5 / 5 (3) Jul 02, 2012
Conservation of angular momentum.

It invalidates your life's work.

You can learn about it in grade 8.

Please do so.

"Vendicar, not once have u asked me a question about my work because u hav a closed mind" - RR
Vendicar_Decarian
5 / 5 (2) Jul 02, 2012
Modern Mystic provides a very good talk by Hansen.

http://www.youtub...embedded

He summs up the problem very nicely.

I add...

http://www.youtub...=related
Vendicar_Decarian
5 / 5 (2) Jul 02, 2012
Not advisable since it will be at the cost of the desertification of the worlds grain belts. Now ongoing in the central and south U.S.

"Yay! Antarctica sucks right now. Some lovely green around the edges would make it much better." - KluckCluck