Via a Euerekalert press release
Past climate of the northern Antarctic Peninsular informs global warming debate
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  IMAGE: The American icebreaker RV/IB Nathanial B. Palmer is shown off the South Shetland Islands. The drilling rig is clearly seen on the rear deck.Click here for more information. |
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The seriousness of current global warming is underlined by a reconstruction of climate at Maxwell Bay in the South Shetland Islands of the Antarctic Peninsula over approximately the last 14,000 years, which appears to show that the current warming and widespread loss of glacial ice are unprecedented.
“At no time during the last 14 thousand years was there a period of climate warming and loss of ice as large and regionally synchronous as that we are now witnessing in the Antarctic Peninsula,” says team member Dr Steve Bohaty of the National Oceanography Centre, Southampton (NOCS), home of the University of Southampton’s School of Ocean and Earth Science (SOES).”
The findings are based on a detailed analysis of the thickest Holocene sediment core yet drilled in the Antarctic Peninsula. “By studying the climate history of the past and identifying causes of these changes, we are better placed to evaluate current climate change and its impacts in the Antarctic,” says Dr Bohaty.
As part of a 2005 research cruise aboard the American icebreaker RV/IB Nathanial B. Palmer, the scientists drilled down through the sediments at Maxwell Bay, a fjord at the northwest tip of the Antarctic Peninsula. They drilled down as far as the bedrock, obtaining a nearly complete 108.3-metre sediment core.
Back in the lab, they performed a battery of detailed sedimentological and geochemical analyses on the core. Radiocarbon dating showed that the oldest sediments at the bottom of the core were deposited between 14.1 and 14.8 thousand years ago, and sedimentation rates at the site varied from 0.7 to around 30 milimetres a year through the Holocene; that is, the geological period that began around 11,700 years ago, continuing to the present.
They conclude that ice was grounded in the fjord during the Last Glacial Maximum – the height of the last ice age – and eroded older sediments from the fjord. Later, the grounded ice retreated, leaving a permanent floating ice canopy.
The evidence points to a period of rapid glacial retreat from 10.1 to 8.2 thousand years ago, followed by a period of reduced sea-ice cover and warm water conditions occurring between 8.2 and 5.9 thousand years ago. An important finding of the study is that the mid-Holocene warming interval does not appear to have occurred synchronously throughout the region, and its timing and duration was most likely influenced at different sites by local oceanographic controls, as well as physical geography.
Following the mid-Holocene warming interval, the climate gradually cooled over the next three thousand years or so, resulting in more extensive sea-ice cover in the bay. But the researchers find no evidence that the ice advanced in Maxwell Bay during the so-called Little Ice Age in the sixteenth to mid-nineteenth century.
The Antarctic Peninsula area has warmed 3 °C in the past five decades, with increased rainfall and a widespread retreat of glaciers. “Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
The study was supported by the US National Science Foundation Office of Polar Programs.
The authors are: K. T. Milliken and J. B. Anderson (Rice University), J.S. Wellner (University of Houston), S.M. Bohaty (NOCS/SOES) and P.L. Manley (Middlebury College, Vermont).
Publication:
Milliken, K. T., et al. High-resolution Holocene climate record from Maxwell Bay, South Shetland Islands, Antarctica. Geological Society of America Bulletin 121, 1711-1725 (2009).
http://gsabulletin.gsapubs.org/content/121/11-12/1711
Far from home, a massive ice slab implies global cooling — how else could it last such a long distance floating in the ocean?
Must be one of these:
http://nsidc.org/data/iceshelves_images/ross_w_loc.html
The image shows many lesser and several greater pieces of the Ross Ice Shelf. Dated January 2003
What is a sheet of brittle ice supposed to do when the water it is floating on lifts and falls? This is not complicated nor a trick question.
Did your CSS die for some reason? The WUWT website template is broken….
REPLY: no problems I’m aware of. – A
SO what if these studies had to also post the grant application and the conditions of the grant as part of their study results? If all corporate funded studies are invalid because of the source of funding, does not the same logic apply to all government funded studies?
You’ve got to be kidding. It never ends.
It really is worse than we thought.
Mike L. and Anthony
An hour or so ago I had a strange rendering of one of the threads but switched to another and back again and it was fine. Has been fine since.
Noelene (17:58:31) :
The seas haven’t been this cold to support Icebergs that far away from the Poles in a very long time. Yes, it’s worse than they thought. Trouble is, nobody taught them how to think it through. I’ve a bit of advice for them: When in a dim room, remove your sunglasses before you stumble over the furniture and suffer needless injury.
“Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
We are supposed to take their word for it. Yet none have demonstrated the link between the weather alteration observed in the Peninsula and the greenhouse effect and its CO2. What is known though is the renewed strength of MPHs coming from Antarctica and the correlative increase of warm air advection along the mountain ranges of the Peninsula, with increased snow and warming associated to this advection of warmer air.
Indeed this is linked to a global phenomenon but unfortunately for these researchers, this on the contrary demonstrates the effects of a rapid mode of circulation linked to cooling not warming. But the meteorological ignorance of these people knows no bound and is at the root of their so called “obvious culprit”.
That such ad hoc conclusions would be thrown to the face of science shows the utter opportunism and how these people despise and insult the intelligence of their readership. Shame indeed!
John F. Hultquist (20:23:24) :
Mike Lorrey (19:51:35) :
Did your CSS die for some reason? The WUWT website template is broken….
REPLY: no problems I’m aware of. – A
I’ve also noticed this kind of thing a few times over the years- but not only on this site. It just seems to be one of those things that happens in web land from time to time.
Ed,
The Vostok CO2 concentrations shown in your link are interesting:
http://s852.photobucket.com/albums/ab89/etregembo/?action=view¤t=Vostok-2.jpg
The graph shows a range of up to 2 ppm over the past 10,000 years. I assume there’s an error here ?
In the abstract they say, “There is no evidence for an early Holocene climatic reversal, as recorded farther south at the Palmer Deep drill site.” So what was found at the nearby site?
A little google search on the Palmer Deep Drill site found:
http://www-odp.tamu.edu/publications/178_SR/chap_34/chap_34.htm
“All studies performed to date are in agreement in recognizing the Little Ice Age as a prominent episode in the latest Holocene from 0.7 to 0.2 ka”
So much for a single core in one unusual location. And we now know without a doubt that it is an unusual site because it did not show the little ice age. Therefore none of their conclusions are valid.
Dr A Burns (21:01:26) :
The graph shows a range of up to 2 ppm over the past 10,000 years. I assume there’s an error here ?
Doh! Yeah that’s temp, thanks for pointing that out!
Ed
Dr A Burns (21:01:26) :
I wish the CO2 contained that high of a resolution!
Ed
Gary P (21:23:24) :
Wow. They actually found the source of the Yamal tree. Now, that’s significant. All you have to do to restore the Garden of Eden is to take the Yamal tree and plug it into Palmer deep drill site hole.
Antarctica lights up, hydraulic cyclinders active, and underneath the ice canopy is the city of Atlantis, where they greet us with “What took you so long? We’ve been waiting 14,500 years to be rescued”.
“the current warming and widespread loss of glacial ice are unprecedented”.
Wow, look at all the scientific disaster reports over the last few years — what the hell were these so called scientists doing for the previous 50 years?
Google for World Climate Report for 30 January 2009 ‘Antarctica Again’. This review shows that most of Antarctica has not warmed since the early 1970s.
The exception is a small atypical region, the narrow Antarctic Peninsula which juts far out from the continent, and may contact a warm current as a result, according to Duncan Wingham. Google for ‘Polar Scientists On Thin Ice’, National Post Canada, 2 February 2007.
“‘Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,’ say the researchers.”
It’s just lazy and lame.
OT but Roman Warm Period has been deleted from Wiki
http://en.wikipedia.org/wiki/Roman_Warm_Period
1984, anyone?
Noelene,
thanks for the heads-up on the Macquarie iceberg. There is a verygood possibility that it could pass off the south east coast of New Zealand just as a bunch of them did three years ago at this time of year. If you check out the SST anomalies for most of this year there has been a lerge pool of cold water off our (N.Z.) south east coast, even colder than the water that was there in 2006.
Apart from the mad so and so’s who will want to copy the couple who went out by helicopter and got married on one of the bergs, I will predict now that we will also see a repeat pronouncement from the local greens that this is more evidence of global warming. Once again they will completely miss the point that if it weren’t for the cold water below and to the S.E. of us then the bergs wouldn’t survive this far north.
I suppose while they are listening to this fable of the Antarctic Peninsula being the Antarctic they will also miss the fact that the sea ice extent around the Antarctic has greatly increased over recent years. Correct me if I am wrong but this must add to the chances of bergs making it to lower latitudes than normal.
The greens and other simple minded folk will also miss the fact that this was not an infrequent event as recorded from the 1890’s through to the beginning of the 1930’s. Therefore by their logic if global warming is the cause of icebergs making it to latitude 43 south as happened in 2006, then there must have been stronger global warming at the beginning of the 20th century!
Anyway, the helicopter pilots of the east coast South Island will be rubbing their hands, not just because it has been very cold down there this year, but at the prospects of more adventures on floating ice islands, no matter how dangerous it may be.
Cheers
Coops
It is funny that they drilled in the one area that ice levels are worried most while everywhere else is ok
http://www.dailytelegraph.com.au/travel/news/ice-cap-could-be-widening/story-e6frezi0-1225700056004
“Atmospheric warming trends linked to global climate change are an obvious culprit for the observed regional climate changes,” say the researchers.
…So climate change is caused by climate change. Brilliant. Is this from the University of Mickey Mouse?
“Now everything is ‘linked’ by mysterious, undefined and un-named mechanisms”.
…Well, global warming has now been defined as a religion.
Dear UK government,
We at The National Oceanography Centre, Southampton (NOCS), home of the University of Southampton’s School of Ocean and Earth Science (SOES} have traveled a long way to the northern Antarctic Peninsular and taken an ice core sample. From this single sample we have managed to delete from the Earth’s climate history some inconvenient facts such as the Little Ice Age, the mid-Holocene global warming interval and the Medieval Warm Period.
Can we have our next research grant now?
Surely this is the volcanic part of Antarctica. Is this the reason for temperature increase?
“We are supposed to take their word for it. Yet none have demonstrated the link between the weather alteration observed in the Peninsula and the greenhouse effect and its CO2.”
Good point Antonio San
In published articles, the authors usually provide details of some work they have done and their deductions. If there is space, they wiill often add some discussion.
It is usually the case that the discussion doesn’t follow their analysis, but seeks to give some broader context. As such, the discussion is no more than personal opinion. It doesn’t follow from observation or data, and therefore cannot be elevated to “science”.
However, the discussion is frequently sympathetic to the AGW hypothesis. So the inclusion of discussion points gives the false impression that there is more evidence for the AGW hypothesis.
Further, the non-scientific discussion has a contaminating influence, as the article may then be added to the “count-me-in” list when seeking to measure the relative weight of scientific evidence (as per Oreskes).
Here is an example of discussion in the Caillon et al (2003), the paper which reported a 800 +/- 200 year lag at Termination III, and often cited on both sides of the debate:
“This confirms that CO2 is not the forcing that initially drives the climatic
system during a deglaciation. Rather, deglaciation is probably initiated by some insolation forcing (1, 31, 32), which influences first the temperature change in Antarctica (and possibly in part of the Southern Hemisphere) and then the CO2. This sequence of events is still in full agreement with the idea that CO2 plays, through its greenhouse effect, a key role in amplifying the initial orbital forcing.”
The first point (CO2 is not the inital forcing) does not follow from the analysis being reported. It is fair to say that CO2 following temperature gives some direction to causality arguments, but it looks like Caillon et al do not want to leave the matter at that.
The second point (warming probably initiated by insolation) is clearly speculative and certainly doesn’t come from their analysis.
The conclusion of this paragraph (this sequence is in agreement with the idea the CO2 plays a key role in amplifying the initial forcing) is both speculative AND it doesn’t follow from the data and analysis.
Maybe this would be useful?
http://www.john-daly.com/stations/s-orkney.gif
Probably not relevant for this article but : does ice have a viscosity, by which I mean, do some layers flow faster than others? If that is the case, then how is that taken into account when analysing a sample taken by drilling vertically?
“the current warming and widespread loss of glacial ice are unprecedented”
So what! Where’s the evidence that man’s activities have caused it bar a coincidental rise in C02, of which barely 4% is attribuatable to mankind?
Interesting full page article in the UK’s regional paper the WEestern Morning News, serving Devon & Cornwall & parts of Somerset. It is by a former BBC weatherman in which he debuncks that whole AGW theory. I will try to get a link for it asap but I am the one who can just about switch one of these puter thingies on!