Study explains early warming of West Antarctica at end of last ice age
CORVALLIS, Ore. – West Antarctica began emerging from the last ice age about 22,000 years ago – well before other regions of Antarctica and the rest of the world, according to a team of scientists who analyzed a two-mile-long ice core, one of the deepest ever drilled in Antarctica.
Scientists say that changes in the amount of solar energy triggered the warming of West Antarctica and the subsequent release of carbon dioxide (CO2) from the Southern Ocean amplified the effect and resulted in warming on a global scale, eventually ending the ice age.
Results of the study were published this week in the journal Nature. The authors are all members of the West Antarctic Ice Sheet Divide project, which was funded by the National Science Foundation.
The study is significant because it adds to the growing body of scientific understanding about how the Earth emerges from an ice age. Edward Brook, an Oregon State University paleoclimatologist and co-author on the Nature study, said the key to this new discovery about West Antarctica resulted from analysis of the 3,405-meter ice core.
“This ice core is special because it came from a place in West Antarctica where the snowfall is very high and left an average of 20 inches of ice or more per year to study,” said Brook, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “Not only did it allow us to provide more accurate dating because we can count the layers, it gave us a ton more data – and those data clearly show an earlier warming of the region than was previously thought.”
Previous studies have pointed to changes in the Earth’s orbit around the sun as the initial trigger in deglaciation during the last ice age. An increase in the intensity of summer sunlight in the northern hemisphere melted ice sheets in Canada and Europe starting at about 20,000 years ago and is believed to have triggered warming elsewhere on the globe.
It previously was thought that Antarctica started its major warming a few thousand years later, at about 18,000 years before present. However, the new study shows that at least part of Antarctica started to warm 2,000 to 4,000 years before this. The authors hypothesize that changes in the total amount of sunlight in Antarctica and melt-back of sea ice caused early warming at this coastal site – warming that is not recorded by ice cores in the interior of the continent.
“The site of the core is near the coast and it conceivably feels the coastal influence much more so than the inland sites where most of the high-elevation East Antarctic cores have been drilled,” Brook said. “As the sunlight increased, it reduced the amount of sea ice in the Southern Ocean and warmed West Antarctica. The subsequent rise of CO2 then escalated the process on a global scale.”
“What is new here is our observation that West Antarctica did not wait for a cue from the Northern Hemisphere before it began warming,” Brook said, “What hasn’t changed is that the initial warming and melting of the ice sheets triggered the release of CO2 from the oceans, which accelerated the demise of the ice age.”
Brook said the recent increase in CO2 via human causes is also warming the planet, “but much more rapidly.”
They fail to mention any role for the most important GHG (water vapor). It seems they’re really arguing that solar insolation is almost completely responsible, and that increased atmospheric CO2 is an effect, rather than a cause, of warming.
Very cyclical this CO2
http://www.daviesand.com/Choices/Precautionary_Planning/New_Data/IceCores1.gif
They are out to lunch. First of all the CO2 increases are a result of the warming,not the cause. One can see that clearly by looking at past temperature changes versus CO2 changes. Temperature change leads CO2.
Secondly the earth reverted back to very near ice age conditions during the Younga Dryas and also had many substancial cooling periods prior to the start of the Younga Dryas and the end of the maximum last glaciation extent, some 20,000 years ago.
So they are COMPLETLY on the wrong path because the earth did NOT emerge from the maximum of the last ice age and stay warm, instead it reverted back many times to very cold conditions once it emerged from the maximum of the last ice age with the Younga Dryas being the last such cold period post the maximum of the last ice age.
Although, another significant cold event took place just 8200 years ago.
Yet CO2 is on the rise through out this time and according to them had a large part in emerging the earth out of the last glaciation, and yet the temperature record shows CLEARLY many sharp pullbacks , which means their argument for a CO2 increase /temp. increase does not hold up. If it did the temperature (severe pullbacks)would not have occurred post the maximum of the last glaciation as CO2 was on the increase according to them.
If anything they have proven that other factors must be at work,to explain the many temperature severe pullbacks since the maximum extent of the last glaciation.
They have proven the opposite of what they are trying to prove.
These people are absolutely in love with CO2. Their logic is basically: orbital forcings caused ONLY the poles to warm which then caused some minor degasing of CO2 from the oceans and this forcing from the extra CO2 caused the rapid melt of continental glaciers between 20,000-12,000 years ago. Fail.
It would be interesting to see what temperature sensitivity to CO2 is needed to increase the global average temperature by at least 8 degrees C AND melt 120 m of ocean sea level equivalent glaciers.
@Salvatore Del Prete:
“They have proven the opposite of what they are trying to prove.”
I agree, and you presented the evidence better than my attempt above.
However, since they did not even know that the earth was not emerging from the last glaciation period when they identified the event as being 22,000 years ago, what else could one expect from them? They are totally clueless about the past history of the earth, and yet they seem to think that CO2 did all of the warming to get the earth into the Holocene. Yet they are alleged “scientists.”?
The field of climatalogy is in need of new innovative approaches and thinking.
The field of climatolgy today is in a very sad state of affairs and the explanations out there are on grade school levels for the most part.
This article being a perfect example.
The 1’s are the atmosphere and the single o is the carbon dioxide. The one 0 is heating up all the 2499 1’s?
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I just can’t believe it!
How does this crap contineu to get through peer review??
There is not one shred of evidence or model data, or anything that shows that the rate of temperature rise “increased” ..ie., was amplified due to CO2!!
All I see is the same old song and dance. Climatewackos interjecting an assumption into data, for which the data do not speak. One of the reviewers should have questioned this! [of course, we all know this is what happens when your buddies review your study with you while you are all having a beer].
Nice “picture worth a thousand words,” there, Kelvin Vaughan (1:44PM). Indeed, belief alone, not reasoning, is the key to selling CAGW. “400 ppm” is like, 400cc (of a medicine) in the public’s mind or something, lol. They don’t even THINK about the rest of the million parts.
Gullible: [AAAHCHOO!] I feel mitherable.
Numbskull: Try “Contac 400” for your cold.
G: Why?
N: Look here. I’ll show you. [breaks open a capsule and they watch for awhile (quite awhile, actually; it’s fascinating!) as all the tiny, colorful, o’s bounce across the table and onto the floor…………..]
G: I don’t know, Numbskill, they look awful small. They just kind of disappear into the carpet.
N: BUT THERE ARE 400 OF THEM!
G [brightens]: Oh, yeah. Hand ’em over. I’ll take 6 to be on the safe side.
It just needs some editing. Specifically, the following four sentences should go, as they are simply the obligatory carbon-centric nonsense put there to please their bosses, the NSF:
…and the subsequent release of carbon dioxide (CO2) from the Southern Ocean amplified the effect and resulted in warming on a global scale, eventually ending the ice age.
The subsequent rise of CO2 then escalated the process on a global scale.”
“What hasn’t changed is that the initial warming and melting of the ice sheets triggered the release of CO2 from the oceans, which accelerated the demise of the ice age.”
Brook said the recent increase in CO2 via human causes is also warming the planet, “but much more rapidly.”
Once you take those out you’ve got, well, something. A grade-schooler could probably do better, but at least they tried.
In response to: Edim – August 15, 2013 at 6:15 am
Edim, I agree, ice core CO2 ppm data is at its best, highly suspect and unreliable.
Near-surface CO2 ppm is highly erratic due to H2O vapor in the air which is the reason Keeling moved to atop Mona Loa. And one doesn’t know if glacial ice was formed by falling snow or wind blown snow …. or how much or when, or if any, of the top snow/ice layer has melted from one decade to the next.
And Esim, for a graphical picture of your stated “seasonal (bi-yearly) temperature cycle causing changes in CO2 ppm” take a look-see at this copy of a Keeling Curve graph @ur momisugly
http://i1019.photobucket.com/albums/af315/SamC_40/keelingcurve.gif
….. and therein you will also see Henry’s Law in action whereby the ingassing/outgassing of the CO2 is determined by the temperatures of both the ocean water and the surface air and/or the partial pressure of the CO2 between the water and the air. And that steady 50+ years increase in CO2 ppm is due to the steady increase in the average temperature of the ocean water during the same 50+ years.
The scientific facts, calculations and conclusion concerning the claims of CO2 causing AGW.
Note: the near-surface atmospheric H2O vapor (humidity) ppm ranges between 1.5% and 4%, except in desert areas, and with the 4% being Tropical conditions.
FACTS:
Concentration of atmospheric “greenhouse” gases
Carbon dioxide (CO2) 394 ppm — 0.0394% —– Specific Heat Capacity – 0.844 kJ/kg K
Water vapor — (H2O) 40,000 ppm – 4.0000% — Specific Heat Capacity – 1.930 kJ/kg K
The average mass of the atmosphere is about 5 quadrillion (5,000,000,000,000,000) metric tons.
CALCULATIONS:
Thus, any portion of the Tropical atmosphere that contains 394 ppm of CO2 and 40,000 ppm of H2O vapor then the quantity of H2O vapor molecules is 101.5 times greater than the quantity of CO2 molecules.
And the Specific Heat Capacity of H2O vapor is 1.086 kJ/kg K greater than the SHC of CO2 or 2.3 times greater. Which means that in any portion of near-surface Tropical air, regardless of what the thermometer temperature is, each H2O vapor molecule will, at any given time, contain 2.3 time more thermal energy than will each molecule of CO2.
And 101.5 times more molecules of H2O vapor that has 2.3 times the heat holding capacity of the CO2 molecules …. means that said total H2O vapor in said portion of the Tropical atmosphere is 233.5 times more effective at “warming” the atmosphere than is the total CO2 in said portion of the Tropical atmosphere.
CONCLUSION:
If both atmospheric H20 vapor and CO2 are considered “greenhouse” gases and there is on average 101.5 times as much H2O vapor with 2.3 times as much Specific Heat Capacity as there is CO2 in the atmosphere ….. then an increase of even 500 ppm of CO2 to a total of 894 ppm should not really be significant relative to any increase in global warming due to a “greenhouse gas effect” because the H2O vapor would still be 44.7 times greater and/or be 102.8 times more effective at “warming” the atmosphere than is the total amount CO2 in the atmosphere,
And thus, the overwhelming amount of H20 vapor in the atmosphere as compared to the amount of CO2 that is intermixed with it will completely overshadow any warming effects of the CO2 by a factor of 102.8 and thus render it impossible for anyone to be blaming and/or attributing any of said “warming” on said CO2.
And/or, the increased “warming” effect of the near surface atmosphere that would be caused by an additional 500 ppm of CO2 would be so miniscule as to be unmeasurable via Surface Station thermometers.
Now the above factual commentary is not obvious to the casual viewer/researcher during periods of full or partial Sunshine due to the incoming Solar radiation. But it does become obvious as night time approaches and/or during daytime whenever thick cloud cover quickly moves in and blocks the incoming Sunshine.
Near-surface temperatures quickly cool a few degrees when above said cloud cover occurs.
Near-surface temperatures in desert areas of extremely low humidity (H2O vapor ppm) cool very quickly at night time.
Whereas, near-surface temperatures in non-desert areas of 1.5% to 4% H2O vapor (humidity) DO NOT cool very quickly at night time and thus will remain “warm” to “hot” long into the night time hours..
Also, in temperate zones, the Month of September is noted for “hot” days and ”cool” nights simply because the Month of September is also noted for its low humidity (H2O vapor ppm).
Now in closing, if it were true what the proponents of CO2 causing AGW have been claiming, … that the past 100 ppm increase in atmospheric CO2 ppm is responsible for a 1 (one) degree C increase in average surface temperatures …… then a July increase of 20,000 ppm in H2O vapor (humidity) would increase the surface temperatures enough to burn the socks off your feet while standing in knee deep water.
I do not believe it is possible for anyone to measure the heating effect of the lesser quantity of gas (CO2) in a mixture of two different gases when the quantity of the greater volume of gas (H2O vapor) is constantly changing from hour to hour and day to day. Especially when said greater volume of gas has a 100+- times greater “warming” potential for said mixture than does the lesser volume of said gas in said mixture.
F. Ross says:
August 14, 2013 at 9:33 pm
Did the author(s?) give any consideration to the possibility of geothermal activity in W. Antarctica?
Probably not; after all, what else could it be but CO2?
My thoughts exactly!
Also, didn’t that wee scamp Sami Solanki at the Max Plank Instiute conclude that the Sun is burning brighter now than at any time than it did 11,500 years ago, back in what was it ’08/’09? rather a coincidence for me, if it burned as bright back then, causing the seas to warm etc! Just saying. All you scientists out there have said plenty on this paper, which I suggest should be fully collated, cut into little A5 rectangles, have a small hole placed in the top left (or right – no wish to upset anyone), & hung on a nail in the smallest room in the lab building!
At the height of the last glaciation C02 was at 4000 ppm. That means of course that most f the commentary on carbon is absolutely wrong.
Did you rea;lize that they also discovered a mountain higher than Everest?
Quote
– West Antarctica began emerging from the last ice age about 22,000 years ago – well before other regions of Antarctica and the rest of the world, according to a team of scientists who analyzed a two-mile-long ice core, one of the deepest ever drilled in Antarctica.
……..
“This ice core is special because it came from a place in West Antarctica where the snowfall is very high and left an average of 20 inches of ice or more per year to study,” said Brook, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.
End of quote.
Now an average of 20 inches per year for 22 000 years is 440 000 inches. Divide by 12 to get feet. This is 36 666 ft. Divide by 5280 to get miles, hey presto, West Antarctica has a mountain 6.944 miles high.
Beats Everest, though this doesn’t quite make the 40 000 ft and 6 inches height of Rum Doodle. Never mind, just as good fiction.
“rea;lize” should of course be “realize”. However, if the “20 inches of ice or more per year” is in fact ‘more’, it may well have beaten Rum Doodle.