Meanwhile today while CO2 is increasing, the Antarctic ice cap is also increasing.
Bill Illis writes about it:
Ice sheets formed in Antarctica about 35 million years ago when CO2 was about 1,200 ppm. Ice sheets also formed in Antarctica about 350 to 290 million years ago when CO2 was about 350 ppm. Ice sheets also formed in Antarctica about 450 to 430 million years ago when CO2 was about 4,500 ppm. The more common denominator is when continental drift places Antarctica at the south pole.
Below, Antarctica today.
New data illuminates Antarctic ice cap formation
From a Bristol University Press release issued 13 September 2009
A paper published in Nature
New carbon dioxide data confirm that formation of the Antarctic ice-cap some 33.5 million years ago was due to declining carbon dioxide in the atmosphere.
A team of scientists from Bristol, Cardiff and Texas A&M universities braved the lions and hyenas of a small East African village to extract microfossils from rocks which have revealed the level of CO2 in the Earth’s atmosphere at the time of the formation of the ice-cap.
Geologists have long speculated that the formation of the Antarctic ice-cap was caused by a gradually diminishing natural greenhouse effect. The study’s findings, published in Nature online, confirm that atmospheric CO2 started to decline about 34 million years ago, during the period known to geologists as the Eocene – Oligocene climate transition, and that the ice sheet began to form about 33.5 million years ago when CO2 in the atmosphere reached a tipping point of around 760 parts per million (by volume).
The new findings will add to the debate around rising CO2 levels in the Earth’s atmosphere as the world’s attention turns to the UN Climate Conference in Copenhagen which opens later this year.
Dr Gavin Foster from the University of Bristol and a co-author on the paper said: “By using a rather unique set of samples from Tanzania and a new analytical technique that I developed, we have, for the first time, been able to reconstruct the concentration of CO2 across the Eocene-Oligocene boundary – the time period about 33.5 million years ago when ice sheets first started to grow on Eastern Antarctica. “
Professor Paul Pearson from Cardiff University’s School of Earth and Ocean Sciences, who led the mission to the remote East Africa village of Stakishari said: “About 34 million years ago the Earth experienced a mysterious cooling trend. Glaciers and small ice sheets developed in Antarctica, sea levels fell and temperate forests began to displace tropical-type vegetation in many areas.
“The period culminated in the rapid development of a continental-scale ice sheet on Antarctica, which has been there ever since. We therefore set out to establish whether there was a substantial decline in atmospheric carbon dioxide levels as the Antarctic ice sheet began to grow.”
Co-author Dr Bridget Wade from Texas A&M University Department of Geology and Geophysics added: “This was the biggest climate switch since the extinction of the dinosaurs 65 million years ago.
“Our study is the first to provide a direct link between the establishment of an ice sheet on Antarctica and atmospheric carbon dioxide levels and therefore confirms the relationship between carbon dioxide levels in the atmosphere and global climate.”
The team mapped large expanses of bush and wilderness and pieced together the underlying local rock formations using occasional outcrops of rocks and stream beds. Eventually they discovered sediments of the right age near a traditional African village called Stakishari. By assembling a drilling rig and extracting hundreds of meters of samples from under the ground they were able to obtain exactly the piece of Earth’s history they had been searching for.
Further information:
The paper:Atmospheric carbon dioxide through the Eocene–Oligocene climate transition. Paul N. Pearson, Gavin L. Foster & Bridget S. Wade. Nature online, Sunday 13th September.
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we have, for the first time, been able to reconstruct the concentration of CO2 across the Eocene-Oligocene boundary – the time period about 33.5 million years ago when ice sheets first started to grow on Eastern Antarctica. “
Professor Paul Pearson from Cardiff University’s School of Earth and Ocean Sciences, who led the mission to the remote East Africa village of Stakishari said: “About 34 million years ago the Earth experienced a mysterious cooling trend. Glaciers and small ice sheets developed in Antarctica, sea levels fell and temperate forests began to displace tropical-type vegetation in many areas.
“The period culminated in the rapid development of a continental-scale ice sheet on Antarctica, which has been there ever since. We therefore set out to establish whether there was a substantial decline in atmospheric carbon dioxide levels as the Antarctic ice sheet began to grow.”
Like much in the Earth’s climate, what is cause? and what is effect?, is not clear.
We know atmospheric CO2 levels decline as the climate cools due to greater soluability in water. Whether declining CO2 was a contributing cause of the formation of the Antarctic icecap is unclear. More likely, declining CO2 levels acted as a weak positive feedback as the climate cooled.
The most important feedback would have been the ice accumulation itself. Once the icesheet started to form, the Earth’s climate would have rapidly cooled.
In fact, it’s something of a mystery how we avoid runaway cooling and ending up with a snowball Earth.
http://en.wikipedia.org/wiki/Snowball_earth
Bill Illis,
Curious to know if you think the large meteorite that hit earth about 35 million years ago (that created the now buried mile-deep and 50 mile across Chesapeake Bay Impact Crater…
…was one of the causes of the cooling that suddenly began at about the same time?
Thanks.
Chris
Norfolk, VA, USA
Well, at least there is an admission here that Earth’s climate does change, even dramatically sometimes, without mankind’s doings – oops, I meant to say personkind’s doings. Or are they going to go drill another hole somewhere in Africa and thereby discover that there was a huge preindustrial population ‘way back then, and all the people froze during a severe tropical winter? Maybe they all stopped breathing, and then Antarctica froze over? Or are they confusing cause and effect once again?
I find it intesting that the group is so focused on Antartica. Is this the last bastion of deniability. Deniability is a loosing cause in the artic now. Satellite pictures can now show that there is definite shrinkage of north polar ice.
http://earthobservatory.nasa.gov/IOTD/view.php?id=8239
Even antartica is following AGW theory. Above is Nasa’s map of temperature change since about 1980. Its just cold in Antartica and really not melt seriously for awhile. The northern artic is a different case. 6 feet of sea level rise swamps some of the most agriculturally productive land in the world. Plus just now being studied is acidification of the world’s oceans.
After awhile denial will no where to turn when antartica also goes.
grandpa boris (17:11:04) :
William, let’s ignore for the moment the unlikely outcome of the “global melt”. If the ice shields of Greenland and Antarctica melt, what will be exposed is not usable land, but the base rock scoured clean. It will take tens of thousands of years for that rock to become fertile soil
If we could collect, compost, and stockpile all the bovine excrement being put out by the climate alarmist propagandists, when the ice disappears from Greenland and Antarctica, we ought to to have sufficient quantities of nice organic topsoil to cover both places to a depth that matches preColonial Iowa.
Wow – talk about revisionist? A whole new version of history according a specific religious dogma of CO2 and global warming. The theory of Continental Drift is now superseded by religious CO2 dogma.
You have to wonder what will be next? Perhaps after all it wasn’t fruit that Adam ate from the Garden of Eden…perhaps he opened a can of Coca Cola and was the first to poison the planet with CO2!!!!!!!!!!
As a process engineer, let me state that any comparison to any period when Antarctica was not located at the south pole is 100% irrelevant.
Jeff Green
i dunno much about the artic, is it following a similar trend too the arctic? And six foot sea level rises have flooded the best land already!!! i did not know that! Living on an island nation in the pacific we often miss out on all the sea level news here! Its probably a conspiracy by big oil keeping us in the dark.
Yes this climate change stuff is a worry, i mean the earth has had a totally stable climate forever, then man comes along and starts measuring it, and we realise we are heading for thermogeddon(or during the 50s/60s trend the icealypse was nearly upon us. I propose we stop measuring stuff 🙂
The problem I have with research of this type is in the summary or conclusion. Where is the link , the casaulity, between “declining” CO2 and the formation of the Antarctic?
Have our researchers really gotten to the point where they won’t conclusively state a position that isn’t linked to CAGW, or isn’t a predetermined outcome?
Too many assumptions to mention. Who knows what went on in the past? Unique, unverifiable events of history are just the gossip of the “science” world.
Re: Adam from Kansas (13:49:54)
I, too, am a Christian but I would like for you to convince me (and I am completely open to be convinced) that a short time frame for all historical events are necessary based on Genesis 1. Go to http://www.mtgileadchurch.net and email me if you want to correspond.
Adam from Kansas says:
And, whose idea is this exactly? It is certainly not the idea of scientists who know very well that CO2 levels have been higher and the earth’s temperature warmer in the past. However, CO2 levels are at the highest they’ve been in at least 750,000 years (as ice core data show) and likely the highest in millions of years which means, among other things, that homo sapiens were not around to experience those previous higher CO2 levels. (And, by the way, just for the record, being a Christian does not preclude accepting the modern science of geology and even biology…In fact, the Catholic Church accepts it.)
J.H. Folsom says:
It does nothing of the sort. We certainly have more than enough coal to raise CO2 levels to 760ppm and beyond. Furthermore, what we are apparently talking about is the CO2 level when ice sheets first formed. If ice sheets across all of Antarctica were to completely melt then sea level rise would be something like 70 m, which needless to say, is a much larger sea level rise than anybody has been contemplating (because noone has been expecting the East Antarctic ice sheet to melt) and would be much more than a slight problem!
In fact, it seems rather frightening that 760ppm is the level at which this occurs…and one can only hope that there is hysteresis in the system (which is quite possible because of ice-albedo effects) so that it is not completely reversible and it will take a higher level than 760 ppm of CO2 to melt the entire Antarctic ice sheet. Otherwise, frankly, we are pretty much screwed!
Peter Plail (14:08:41) :
Can any geologists out there confirm that “geologists have long speculated that the formation of the Antarctic ice-cap was caused by a gradually diminishing natural greenhouse effect”.
No, but I have a few blank periods in my memory like back in the 60’s drinking overproof rum with a coke chaser in the Palace Grand in Dawson City YT. I do remember that the coke cost more than the rum.
Berry R
Best post I’ve ever seen on here …
@ur momisugly Smokey (15:44:54) :
By volume (rounded), the gas concentration of air includes 78% nitrogen (N2) and 21% oxygen (O2) with the remaining made up of gases including argon (1%), water vapor (0-1%), carbon dioxide (.04%), and other trace gases. The greenhouse effect from natural greenhouse gas concentrations prior to the Industrial Revolution has kept the Earth’s surface about 33 degrees C warmer than with an atmosphere with no greenhouse gases. Although greenhouse gas concentrations appear to be small, their effect is certainly not.
There is a common misconception that the concentration levels of carbon dioxide are so small that they could not possibly be causing global warming. As mentioned previously, the natural greenhouse effect (from gas concentrations before the Industrial Revolution) has kept the Earth’s surface about 33 degrees C warmer than with an atmosphere with no greenhouse gases. Pre-Industrial Revolution CO2 levels ranged between 190 ppm and 300 ppm. Today they are rapidly approaching 400 ppm. Because levels of carbon dioxide are well above natural levels, it should not be hard to see how these increases could cause temperatures to rise at least a few degrees C in the future. The 0.7 degree C warming since 1880 has already caused many problems, especially to ecosystems. A 2 degree warming would be quite catastrophic in many ways.
And yes, I know about the CO2 saturation effect.
@ur momisugly ron from Texas (17:32:26) :
You stated: They’re called volcanic eruptions. One decent blow-up puts as much CO2 in the air as all of man’s contribution to date.
False. Not even close to being true yet this is the type of nonsense that Ian Plimer spouts.
See:
http://tamino.wordpress.com/2009/08/19/co2-and-the-volcanoes/
http://www.grist.org/article/volcanoes-emit-more-co2-than-humans/
The earth and sun were not in the same relative positions in our galaxy way back then. Does this have any effect on the cloudiness and temperature?
Joel Shore,
Antarctica glaciated over when CO2 was 211 ppm, 1,400 ppm, 350 ppm and when it is was 4,700 ppm. Which level are you going to be frightened about?
It is more frightening to think that climate scientists do not know these basic geologic history facts yet people are still listening to them.
“If the ice shields of Greenland and Antarctica melt, what will be exposed is not usable land, but the base rock scoured clean.”
And due to the rock of Greenland being lower in the center than the edges, there will be a very large lake. I don’t remember the current topography of Antarctica.
Aha, I have the perfect thoery:
IGM.
Irregardless Global Modeling.
Irregardless of how many computers are used for Global Modeling, Anthropogens cannot Guarantee a Warm planet.
When you think about it, we are really getting shortchanged. 50 years, that’s it.
The Romans and Medieval Europe got hundreds, ancient civilizations got 1,000s of warm years.
All we got is a 50-year Tee Shirt.
Jeff Green (18:48:28),
The alarmist contingent always concentrates on the North polar ice cover, while studiously ignoring the South Pole, which has been consistently cooling. Globally, averaging the Arctic and the Antarctic shows global cooling:
click1
click2
click3
click4
click5
Global warming over all is non-existent. Data confirms that the planet is cooling. Deal with it.
AnonyMoose (20:10:23) :
Sound like a great inland sea, a Super Lake Tahoe.
I don’t recall ever seeing the topography of Antarctica.
Who the heck wants to run seismic surveys in 70 below or worse.
Scott Mandia (19:54:42) :
Already caused many problems? Like what?
And beneficial in equally indeterminable ways.
Yet choose to ignore it.
Another cart before the horse garbage from Nature the AGW biased journal…
I did a little more digging on the date the Drake passage opened and when widespread, as opposed to mountain glaciers started in Antarctica. If there is consensus on the dates of either of those things it must be fairly recent. The slide-show/animation that someone linked to earlier shows the passage developing exactly at 33 million years ago. If true, that makes linking the glaciers to falling CO2 even more problematic than the date I had read earlier (26 million years ago).
There was also apparently a cluster of asteroid or cometary impacts at about this time, and apparently some geologists link the climate changes around the Eocene/Oligocene boundary (which is geologist-talk for this time period) at least partly to those impacts.
Oops forgot the link to that last bit of info:
http://specialpapers.gsapubs.org/content/452/97.abstract
Peter Plail (14:08:41) :
Can any geologists out there confirm that “geologists have long speculated that the formation of the Antarctic ice-cap was caused by a gradually diminishing natural greenhouse effect”.
I can’t speak for all geologists but I can say that most geologists are skeptics. So much so that Real Climate has a thread devoted to geologists:
http://www.realclimate.org/index.php/archives/2008/08/are-geologists-different/
But I digress. It seems the simplest answer is that [CO2] follows its solubility equation, and so as Antarctica cooled, CO2 would be sequestered and the concentration would fall. No mystery here.
This study reminds me of the recent discoveries of ancient trees in glacial moraines. The news media has been reporting this as evidence of dangerous and unprecedented warming. My geologist and forestry colleagues instead ask: why was it so warm so long ago that forests grew where today there is only alpine tundra?
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VBC-4V2PSYN-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1011873521&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=c8cdbd7496416e73e46941bd4b3425b6
http://web.unbc.ca/~menounos/www/2008GL033172.pdf
If you follow the links you will see that thousands of years ago there were forests where today there is alpine tundra and/or alpine glaciers. The question for me is not why is so warm today, but rather why was it so warm so long ago that there were forests where today trees cannot grow? As for Antarctica, we know it cooled, but CO2 was not likely the cause. In fact there may have been a warm spell recently where CO2 would have been the same as today:
http://findarticles.com/p/articles/mi_m1200/is_v129/ai_4164401/
As to the causes of the warmings and coolings I can say I favour a solar cause, but Leif has convincing arguments that this may not be the case. Perhaps the Earth has major climate oscillations that we have not even begun to understand, or maybe the sun has some tricks up its sleeve that we have not yet seen. I won’t speculate, but I can say the science is never settled.