800,000 years of Greenland's abrupt climate variability

Sep 08, 2011

An international team of scientists, led by Dr Stephen Barker of Cardiff University, has produced a prediction of what climate records from Greenland might look like over the last 800,000 years.

Drill cores taken from Greenland's vast ice sheets provided the first clue that Earth's climate is capable of very rapid transitions and have led to vigorous scientific investigation into the possible causes of abrupt climate change.

Such evidence comes from the accumulation of layers of ancient snow, which compact to form the ice-sheets we see today. Each layer of ice can reveal past temperatures and even evidence for the timing and magnitude of distant storms or . By drilling cores in the ice scientists have reconstructed an incredible record of past climates. Until now such temperature records from Greenland have covered only the last 100,000 years or so.

The team's reconstruction is based on the much longer ice core retrieved from Antarctica and uses a mathematical formulation to extend the Greenland record beyond its current limit.

Dr Barker, Cardiff School of Earth and Ocean Sciences said: "Our approach is based on an earlier suggestion that the record of Antarctic temperature variability could be derived from the Greenland record.

"However, we turned this idea on its head to derive a much longer record for Greenland using the available records from Antarctica."

The research published in the journal Science demonstrates that has been a systemic feature of Earth's climate for hundreds of thousands of years and may play an active role in longer term climate variability through its influence on ice age terminations.

Dr Barker added: "It is intriguing to get an insight into what abrupt climate variability may have looked like before the Greenland records begin. We now have to wait until longer Greenland records are produced so that we can see how successful our prediction is."

The new predictions provide an extended testing bed for the climate models that are used to predict future .

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More information: The research paper titled "800,000 years of abrupt climate variability" is published in the journal Science today.

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User comments : 19

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GSwift7
2.7 / 5 (14) Sep 08, 2011
We now have to wait until longer Greenland records are produced so that we can see how successful our prediction is.


Only if that is true, can the following be true:

The new predictions provide an extended testing bed for the climate models


If I'm reading this right, then all they did here is look at the Antarctic ice cores and then assume that the climate in Greenland follows some kind of predictable pattern in relation to Antarctica. I'm prety sure we know that isn't the case though, don't we? You can't really validate what they have done here until you get some other proxy from Greenland to look at and compare to, but then you don't need to make up a simulated record because you would have an actual field observation.
plaasjaapie
3 / 5 (8) Sep 08, 2011
So where's the beef of this article? This is barely an abstract.
Simonsez
2.5 / 5 (16) Sep 08, 2011
Clearly, human industry has been the cause of all this rapid climate change in the past 800,000 years.
GSwift7
2.3 / 5 (12) Sep 08, 2011
The new predictions provide an extended testing bed for the climate models


This comment is just too rich to ignore. It's got my attention like the way your tounge always goes to the spot where a missing tooth should be.

If I had a climate model, which I don't, but IF I had a climate model, and IF I tested my climate model against the above simulated dataset, I don't think I would be overly concerned if my model didn't agree with the simulated dataset.

Or should all the modelers rush out to get this dataset and then modify their climate models so that they produce results that match the above referenced simulated dataset? That doesn't sound like a good idea to me, but oh well.
william_r_thomas
2.7 / 5 (14) Sep 08, 2011
I have as much faith in climate models as I do in fortune cookies.
omatumr
1.5 / 5 (15) Sep 08, 2011
800,000 years of Greenland's abrupt climate variability . . .


Is a tiny fraction of Earth's continuously changing climate [1-4] and continuously evolving life [5] because the Sun is a variable star unlike the constant heat source assumed in AGW model of Earth's climate and SSM model of a supposedly constant Sun [6].

1. "Sun's origin, composition, source of energy", LPSC (2001) 1041
www.omatumr.com/lpsc.prn.pdf

2. "Super-fluidity, solar eruptions and climate", JFE (2002) 193
http://arxiv.org/.../0501441

3. "Earth's heat source", Energy/Environ 20 (2009) 131
http://arxiv.org/pdf/0905.0704

4. "Neutron repulsion", The APEIRON J, in press (2011)
http://arxiv.org/...2.1499v1

5. "Origin and evolution of life", J Mod Physics 2 (2011) 587
http://dl.dropbox...5079.pdf

6. "Bilderberg Sun", Solar Physics 3 (1968) 5
http://adsabs.har....3....5G

With kind regards,
Oliver K. Manuel
Former NASA PI for Apollo
Shootist
2.5 / 5 (15) Sep 08, 2011
Drill cores taken from Greenland's vast ice sheets provided the first clue that Earth's climate is capable of very rapid transitions


It has been known for decades that the southern coast of, the country formerly known as, England transitioned from deciduous forest to tundra in < 100 years.
MDG
4 / 5 (4) Sep 09, 2011
Agree with some above posts.
What a load of Codswallop.
"Scientists" have already dissociated the Northern Hemisphere weather events from the Southern... IE, Foxtail Curve, discounted all northern hemisphere historical warming / cooling data, relying instead on extrapolated data from Tasmanian Tree rings (Weighted 200:1 or something)..
Now they tell us that they are actually linked....

Who can say that the Antarctic record is complete as it is, there may have been a time of Nett melting therefore hundreds of thousands of years of data would be missing, and it is too old for C-14 to indicate....
gmurphy
2.7 / 5 (12) Sep 09, 2011
@Shootist, citation please. The article is about the Antarctic, not England. @GSwift7, your critiques are obvious, in todays hostile environment towards climate science http://www.guardi...techange , climate scientists are acutely aware that "sceptics" such as yourself will tear apart any perceived weaknesses in a frenzy of self-righteousness. Strange how this scepticism was conspicuously absent when Roy Spencer's flawed climate paper was pompously paraded as the "evidence" that finally disproved CO2 induced global warming.
looseyarn
1.5 / 5 (8) Sep 09, 2011
Sadly the denialists present also in here want Texans to burn.
Magnette
5 / 5 (2) Sep 09, 2011
Drill cores taken from Greenland's vast ice sheets provided the first clue that Earth's climate is capable of very rapid transitions


It has been known for decades that the southern coast of, the country formerly known as, England transitioned from deciduous forest to tundra in < 100 years.


It still is called England as far as I'm aware!

Unfortunately the same level of study has never been carried out here so there is no evidence for comparison.
GSwift7
2.3 / 5 (6) Sep 09, 2011
Strange how this scepticism was conspicuously absent when Roy Spencer's flawed climate paper was pompously paraded as the "evidence" that finally disproved CO2 induced global warming


I posted criticism of the Spencer and Brasswell 2011 paper on sites that covered it, however, that paper was somehow not announced on this site, even though it was a big enough news story to make it onto Slashdot.

In Spencer's recent response to the Dessler paper, which criticizes the Spencer paper, I was happy to note that Spencer did not address Dessler's valid point about ENSO. I hardly see how you can fairly accuse me of playing one side more favorably than the other. I treat both with caution. As with any paper that attempts to refute the majority of other work in the field, the Spencer paper should be viewed with extreme caution. He does make a few points that deserve further discussion, hence the ongoing dialogue between Spencer and Dessler. It's okay for scientists to disagree.
GSwift7
1.8 / 5 (5) Sep 09, 2011
It still is called England as far as I'm aware!

Unfortunately the same level of study has never been carried out here so there is no evidence for comparison


http://noc.ac.uk/...rf/about

I strongly disagree. There are innumerable proxy studies of the history on and around England. We know a TON more about the history of England than we do about Antarctica. The reason you don't hear much about studies of the history of England is because it's old news. There are no ice cores from England, but there are many other types proxy studies of the area.

I don't see how anyone can say that the above story is solid science. The guy says, in his own words, that the results need to be confirmed before the method is proven valid. Until then, it's untested.

We now have to wait until longer Greenland records are produced so that we can see how successful our prediction is


Get off the agenda and just read what he said. This isn't pro or anti AGW in any way.
Nanobanano
2.8 / 5 (6) Sep 09, 2011
Comparing Antarctica and Greenland and trying to make predictions of one based on the other is faulty reasoning.

Antarctica is centered almost symetrically on the south pole. Greenland is centered quite a distance assymetrically from the pole, and the pole is covered by ocean; quite a different scenario.

I don't believe it takes thousands of years to drastically change greenlands climate. I think it can happen in as little as a few hundred, and there is some circumstancial evidence elsewhere on the earth to support the idea.

The precession of the earth's axis can cause the Sahara to go from desert to lakes and grasslands in as little as a few hundred years, though the cycle only happens once every 20,000 years or so. Archeological evidence shows that just several thousand years ago, humans swam in very large inland fresh water lakes in the Sahara, and before that, there were even salt water oceans and lakes inland in the Sahara...
Nanobanano
2.3 / 5 (6) Sep 09, 2011
cont...

There is also archeological evidence that a permanent land bridge once connected England and Europe, and just a few thousand years ago; including ancient submerged forests under the sea, and even remains of ancient human tools and structures under the seas.

This did not require millions or even hundred thousands of years. It happened in just a few thousand to ten thousands of years at most. I suspect the lower end of the estimate, because salt water tends to corrode stuff faster than air or fresh water.

The point I'm getting at is NATURAL climate change on a continental scale, and quite literally from one extreme to another, does not take eons. It can happen in a matter of a few decades or a few centuries: from inland fresh water lakes the size of the American Great Lakes, to barren, lifeless desert in 200 years or so...and at a time when total world human population may have been a million or less...No AGW required...
Nanobanano
2.1 / 5 (7) Sep 09, 2011
And these did not even happen because of "catastrophism". These changes happened because of natural, purely "Earth-only" precession, which little or nothing to do with meteors or volcanism.
GSwift7
1 / 5 (1) Sep 13, 2011
Comparing Antarctica and Greenland and trying to make predictions of one based on the other is faulty reasoning.

Antarctica is centered almost symetrically on the south pole. Greenland is centered quite a distance assymetrically from the pole, and the pole is covered by ocean; quite a different scenario


At this point, there's no way to know if it is faulty reasoning or not. Using the Antarctic cores as a psudo-proxy for Greenland may be perfectly valid. However, as the good Dr points out, it must be verified by an actual proxy of that time period from Greenland. However, that kinda negates the need for a psudo-proxy, if you have an actual proxy, right? lol. I would compare this to the method of using yesterday's weather to predict tomorrow's weather. Adjacent days do tend to be alike. However, you can't really say whether it works until you see what tomorrow's weather actually is, but by then you don't need to predict tomorrow's weather because you already know.
GSwift7
1 / 5 (1) Sep 13, 2011
Using a psudo-proxy of Greenland to test climate models is definitely a wasted effort though. In this case, the psudo-proxy is 100% based on the Antarctic ice cores. So, why would you use the psudo-proxy to test the models? Just take the Antarctice ice cores and test the models against those (which has already been done). Testing the model against a psudo-proxy of Greenland which is based 100% on the Antarcitc ice cores is just a repeat of testing the models against the Antarctic ice cores directly, only adding a layer of uncertainty because you don't know if the psudo-proxy is accurate or not.
GSwift7
1 / 5 (1) Sep 13, 2011
You could do the opposite though; If you have high confidence in the climate model, then you can use it to test the psudo-proxy of Greenland. Do the climate models support the method of using Antarctica to create a psudo-proxy for Greenland, or do the climate models suggest that the climates of Antarctica and Greenland are not strongly coupled? I don't know the answer to that question, but I'm sure that people in that area of research have looked into that question and already have an opinion.

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