It seems Antarctica once had vegetation and had a lot of rain.
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 › Full image and caption
PASADENA, Calif. — 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 plant leaf wax remnants in sediment core samples taken from beneath the Ross Ice Shelf, the research team found summer temperatures 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 Antarctic ice sheet as the climate system 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 sediment cores 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.
“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 Miocene epoch 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 carbon dioxide, 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.
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This research was funded by the U.S. National Science Foundation with additional support from NASA. The California Institute of Technology in Pasadena manages JPL for NASA.
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In case you are wondering (as I did) this is the orientation of the continents 20 million years ago during the Miocene period.
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This is grerat news! What we need to do, however, is to storm the citadel that is education. In the UK, at least, intelligence and learning are the antithesis of education, whose main goal is compliance. Until we get a foothold there, kids will come out of factory-schools believing that the fairy-tails peddled by the IPCC and government departments are true.
None of these speculations can explain the Piri Reis map, which is known to antedate Columbus, and is more accurate on then-unexplored parts of the world than the known regions. It shows Antarctica as it would exist without ice.
[snip. Fake proxy server. ~dbs, mod.]
But, but, but the end of this post seems to say that CO2 caused the warmth? Surely that can’t be true…
“While scientists do not yet know precisely why carbon dioxide was at these levels during the middle Miocene, high carbon dioxide, 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.”
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I think these guys failed the test were you have to put the shaped objects into their matching holes.
They are looking right at yet still missing that maybe, just maybe, the heightened CO2 levels were the result of the warmer temps. OY!
And human produced CO2 had NOTHING to do with it!
… “thought to be associated with CO2 at 400 to 600 ppm …”
Except CO2 was mostly around 250 ppm during this time period.
http://img338.imageshack.us/img338/5300/co2last25mys.png
Temperature vs CO2@3.0C per doubling over the last 40 million years for a little more perspective. I think the temperature estimates here are probably very consistent with what this study found.
http://img716.imageshack.us/img716/1079/tempsvsco240mya.png
Some of the other developments such as ocean currents and continental arrangements which changed over the time period.
http://img844.imageshack.us/img844/6939/tempgeog45mlr.png
Sorry about the “CO2 @ur momisugly 3.0C”. hadn’t realized that would create a link.
“It seems Antarctica once had vegetation and had a lot of rain.”
Rain is the wildcard?
http://wattsupwiththat.com/2012/06/16/younger-dryas-the-rest-of-the-story/#comment-1012401
The Warmist will never except that modern climate conditions can be as variable and changing as it always has, it would just ruin their dream of a UN one world government and all that lovely money flowing into thee power elite and socialist pocket’s. It was never about climate otherwise the earth climate history would be enough to be put this hoax to bed before it even got started.
Yes they do. They know it was high because the temperature was high. What they don’t know is why the temperature was high, and whether CO2 played a significant role as a cause as well as an effect.
“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 Antarctic ice sheet as the climate system heats up. This is some of the first evidence of just how much warmer it was.”
Hmmmm… sounds like we have quite a ways to go before we experience ‘unprecedented’ warming. Climate scientists seem to have jumped the gun.
Meanwhile, that’s quite an interesting article. I appreciate the graphic that showed where they were taking cores. All I could think was “That’s gonna’ be one HECK of a rebound when the ice melts off Antarctica!”
I seem to remember that Captain Scott found coal down there on his last expedition.
Where are the airplanes and rockets? NASA=National (ok I get that part of this study), Aeronautical ( sorry I don’t see what this has to with aeronautics, and I have degree in aeronautics), and (ok I get “and”), Space (gee I don’t see how drilling a hole in the Earth has anything to do with space), Administration (Ok so they they are a bureaucratic arm of government). Why is NASA doing these studies at all?
“At the current rate of increase, atmospheric carbon dioxide levels are on track to reach middle Miocene levels by the end of this century.”
Is there something significant about this statement? I supposed I am supposed to connote some dire meaning. Climate science!
“scientists do not know why carbon dioxide was this high” — must be all of them prehistoric SUVs. Heard Fred Flintstone used to drive a hummer.
TomT says:
June 18, 2012 at 6:44 pm
Where are the airplanes and rockets? NASA=National (ok I get that part of this study), Aeronautical ( sorry I don’t see what this has to with aeronautics, and I have degree in aeronautics), and (ok I get “and”), Space (gee I don’t see how drilling a hole in the Earth has anything to do with space), Administration (Ok so they they are a bureaucratic arm of government). Why is NASA doing these studies at all?
I think it has something to do with their primary task of ‘Muslim Outreach’ http://washingtonexaminer.com/politics/2010/07/nasas-muslim-outreach-al-jazeera-told-first/12338 😉
“By the end of this century climate change will reduce the human population to a few breeding pairs surviving near the Arctic.” – Sir James Lovelock, Revenge of Gaia
Good news! This article shows the “few breeding pairs surviving” will find mild conditions on Antarctica. It’s not as worse as we thought! 🙂
400 to 600 ppm of CO2, everything else equal, will warm the planet, but the question is how much?
If the only important difference between the earth today, and 15 million years ago, was the difference in CO2 levels, then we might well get to the warmth of 15 million years ago. And the large rise in sea levels that would likely occur if Antarctica warmed to the degree in this study.
But there were important differences in ocean circulation patterns that have been argued to have caused the earth to be warmer in the relatively recent past than today, at about the same CO2 levels. One such difference, noted in the map above, is that Central America was not yet completely land, there was a substantial water gap between N and S America. This gap, through which one ocean flowed into another (can’t do that today), and some differences in the Arctic, have been argued to make most of the earth warmer about 3 to 4 million years ago, when CO2 levels were about the same as today. Complex, but it has to do with distribution of heat circulation.
A paper which doesn’t look at that argument, but merely shows that the world was warmer in the mid-Pliocene (3.5 to 3 million years ago) is Dwyer and Chandler, “Mid-Pliocene sea level and continental ice volume based on coupled benthic Mg/Ca palaeotemperatures and oxygen isotopes.” Phil. Trans. R. Soc. A (2009).
This paper shows that at a time when CO2 levels were about what they are now, sea levels varied between 20 to 25 meters higher or lower than today (65 meters lower than today at 3.3 million years ago), with a majority of the time below today’s levels. A look at the graphics in the paper appears to show periodicities not too different that the 100,000 year cycles between interglacials. In other words, it looks like Milankovitch cycles might have been in operation, but because the earth was warmer, the cycles didn’t put us into ice ages, and the peak of the “interglacials” of the mid-Pliocene had sea levels about 20 to 25 meters higher than today.
So we can look at the research in the paper featured in this blog entry, showing the edges of Antarctica being just warm enough to have some stunted trees, and we can think of the warmth of that time having two reasons for being warmer than today. First, the earth was warmer because land forms caused different ocean circulation patterns, and so (as in the Dwyer/Chandler paper) the earth was warmer even when CO2 levels were similar to today. Second, the earth was warmer due to higher CO2 levels of 15 million years ago.
Clearly, if Antarctica got warm enough to have stunted trees, sea levels would be substantially higher than today, a big problem. But we can’t take the results of this paper as being for an earth analogous to today’s. Obviously, we have to avoid sea levels substantially higher than today, but we need to get the science right before we bankrupt economies. We really should make it a priority to do so.
O / T JoNova’s site is now up and running again.
http://joannenova.com.au/
Bet it looked a lot like Viking era Greenland
I love this stuff!!! It causes one to pause and think for a bit. Sadly, I couldn’t get very far without this phrase screaming at me……. “Just as history has a lot to teach us about the future, so does past climate.”
I’ve too much beer in me to be too charitable. Sorry if this sounds mean, but,…… Hey! Here’s an idea, would could actually consider past climate as …..mf’ing HISTORY!!!! Well, we could……
I’ll go back and read for a bit, and check the supposed time frame, but all of these paleo studies…. the ones that go back millions or hundreds of thousands of years…. …. does the continental drift come into play on any of this?
“The ultimate goal of the study was to better understand what the future of climate change may look like,”…
Putting the cart before the horse a little bit, aren’t we? And well, howdy-doody, we suddenly have a window into its PAST. Those nasty Miocene Humans, messing with the climate. Oh, and gee, those oceans didn’t boil after all, now did they, Jim? Jim? Uh…oh never mind.
Did they ever find out what screwed the climate up and made it so cold after it was so nice and warm and toasty? I hope they don’t let that happen again.
Bill Illis says: “Except CO2 was mostly around 250 ppm during this time period.”
Bill, I have never seen any data that look like your chart before. Where does it come from and why is it that you say paleosols aren’t reliable?
On the topic of this study: The question of what was happening near the poles always seems to preoccupy those looking at the paleo record who want to pant scary scenarios for future warming. But this always exaggerates the size of the changes, since polar climates have always been very variable.
During the Eocene, for instance, there is a significant problem with models trying to explain the polar warmth while simultaneously not warming the tropics too much. The magnitude of this problem was worse before there was an extensive effort to get the tropical data to be warmer than the present, because it used to be models gave too cold of poles and too warm of tropics. The data naturally got “fixed” to better agree with models, so that now models apparently can match the tropics…but only if their poles are still much too cold.
It would not at all surprise me if the evidence from the Miocene also indicated a significantly reduced equator to pole temperature difference. The way “climate scientists” speak of this, it is as if they are not interested in asking why this should be the case: temperature changes are basically assumed to follow the Budyko-Izrael distribution automatically.