From the British Antarctic Survey
New climate history adds to understanding of recent Antarctic Peninsula warming
Results published this week by a team of polar scientists from Britain, Australia and France adds a new dimension to our understanding of Antarctic Peninsula climate change and the likely causes of the break-up of its ice shelves.
The first comprehensive reconstruction of a 15,000 year climate history from an ice core collected from James Ross Island in the Antarctic Peninsula region is reported this week in the journal Nature. The scientists reveal that the rapid warming of this region over the last 100 -years has been unprecedented and came on top of a slower natural climate warming that began around 600 years ago. These centuries of continual warming meant that by the time the unusual recent warming began, the Antarctic Peninsula ice shelves were already poised for the dramatic break-ups observed from the 1990’s onwards.
The Antarctic Peninsula is one of the fastest warming places on Earth – average temperatures from meteorological stations near James Ross Island have risen by nearly 2°C in the past 50 years.
Lead author Dr Robert Mulvaney OBE, from British Antarctic Survey (BAS) says,
“This is a really interesting result. One of the key questions that scientists are attempting to answer is how much of the Earth’s recently observed warming is due to natural climate variation and how much can be attributed to human activity since the industrial revolution. The only way we can do this is by looking back through time when the Earth experienced ice ages and warm periods, and ice cores are a very good method for doing this.”
Dr Mulvaney continues,
“We know that something unusual is happening in the Antarctic Peninsula. To find out more we mounted a scientific expedition to collect an ice core from James Ross Island – on the northernmost tip of the Peninsula. Within the 364m long core are layers of snow that fell every year for the last 50,000 years. Sophisticated chemical analysis – at BAS and the NERC Isotope Geosciences Laboratory (part of British Geological Survey) – was used to re-create a temperature record over this period.
“For this study we looked in detail at the last 15,000 years – from the time when the Earth emerged from the last ice age and entered into the current warm period. What we see in the ice core temperature record is that the Antarctic Peninsula warmed by about 6°C as it emerged from the last ice age. By 11,000 years ago the temperature had risen to about 1.3°C warmer than today’s average and other research indicates that the Antarctic Peninsula ice sheet was shrinking at this time and some of the surrounding ice shelves retreated. The local climate then cooled in two stages, reaching a minimum about 600 years ago. The ice shelves on the northern Antarctic Peninsula expanded during this cooling. Approximately 600 years ago the local temperature started to warm again, followed by a more rapid warming in the last 50-100 years that coincides with present-day disintegration of ice shelves and glacier retreat.”
Co-Author Dr Nerilie Abram formerly from British Antarctic Survey and now with the Research School of Earth Sciences, at The Australian National University says,
“The centuries of ongoing warming have meant that marginal ice shelves on the northern Peninsula were poised for the succession of collapses that we have witnessed over the last two decades. And if this rapid warming that we are now seeing continues, we can expect that ice shelves further south along the Peninsula that have been stable for thousands of years will also become vulnerable.”
Olivier Alemany, from the French Laboratoire de Glaciologie et Géophysique de l’Environnement was part of the expedition. He says,
“The international polar science community has collected and analysed ice cores from Antarctica and Greenland as part of an effort to reconstruct the Earth’s past climate and atmosphere. Our team wanted to understand how the recent warming and the loss of ice shelves compared to the longer term climate trends in the region.”
This research makes a significant contribution to the understanding of the role that Antarctica’s ice sheets play in influencing future climate and sea-level rise. It was funded by NERC (Natural Environment Research Council).
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Regarding that rapid warming of 2C in the last 50 years, just remember that most weather stations in the Antarctic are near humanity, and humanity requires warmth to survive. For example:
The Antarctic peninsula is the most populated place in Antarctica.
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I had a look at their detailed data in the Supplemental versus the high resolution Antarctic summit ice core numbers.
The Pennisula appears to have warmed up earlier out of the ice age than the summit and the warming was more pronounced around 12,000 years ago. It also does not vary as much as the Summit (which is important for those taking the proxy data and turning it into temperature reconstructions – some climate scientists do not seem to understand that different locations have different formula).
The Older Dryas cooling event (14,300 years ago) starts about the same time in the Pennisula and the Summit but the Pennisula does not show any kind of Younger Dryas cooling event (12,800 years ago) – it was already warming very fast at this time. This is something someone should look at since we are trying to understand this/these event(s).
Otherwise quite similar for the last 8,000 years.
Of course if they really wanted to nail down the possible local temperature bias of the huts and sensor locations, they could set up a matrix of 6 or 8 sensors spaced out away from the station and get contemporary readings from all of them and see if there is a heat island effect from the proximity.
Even a single additional sensor station 1000 meters from the station would help characterize any possible bias in the measurements. Given how much they spent to put all that hardware on the ice, you would think the additional cost of one more temperature sensor would be a trivial concern, and simple way to validate the sensitivity to local heat island effects from the structures.
Why don’t any of these outposts seem to have redundant sensors?
Larry
A few weeks ago my article on temperatures was carried here;
http://wattsupwiththat.com/2012/08/14/little-ice-age-thermometers-historic-variations-in-temperatures-part-3-best-confirms-extended-period-of-warming/
I observed a 400/500 year warming tremd from CET which was confirmed by a warming trend from 1753 by BEST.
This coincides with the 600 year warming trend observed in the Antarctic. BEST, Hadley and Giss merely plugged into a warming trend that was already well established and didn’t indicate the start of it. It predates enhanced co2 by many centuries. Is anyone looking for the cause?
tonyb
Robuk
August 23, 2012 at 5:44 am
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If you had bothered to read any of the comments you would have known that the press release was changed because of an email sent by ScousePete.
ScousePete is being very generous. It is obvious that the “error” was the standard deliberate attempt to spin a research paper in order to better support the cause. Got to keep headline propaganda going or else the brain washed masses will forget. Lefties see everything through the lens of their agenda and are willing to lie(etc.) for it. Most don’t even know that they are doing it because their ability to think and remember has been so compromised by the Marxist world-view that they have been programed to have. /soapbox
The catastrophic warnings have been lapped up by my dear relative. Penguins are dying. The ice cap is melting. We are all going to fry on land and boil in the oceans. You know what? It gets my dander quite up and my Irish feathers terribly ruffled when a good and decent woman is fooled by dishonest rhetoric of the kind we are seeing in the latest emails and correspondance FOIA stash. The way these charletans work at twisting the words for greater impact! For shame! And to put a point on it, this isn’t mainstream media I am talking about, but the very people who are degreed in research!
Those that work at this attempt to rile the populous to unnecessary worry and those that let it slide without protest ought to be tarred and feathered and run out of town on the rails. You are, as a bunch and in total, no longer good enough to sweep the floor of research, let alone have your writings see the light of day.
And these are my kind words!
Question for the experts:
http://en.wikipedia.org/wiki/File:SouthPoleStationDestinationAlpha.jpg
Amundsen-Scott South Pole Station, Destination Alpha side (one of two main entrances), 2009, resolution up to 4,483 × 2,989px available.
I was looking at the pics for the station at the Wikipedia entry for a Stevenson Screen, saw something else.
See the thing at the front left corner hanging off the roof of the building on a short mast? It doesn’t look like a light, there’s nothing else like it elsewhere around the building (that I can see). It looks like it’s open at the bottom for air circulation, with an opaque white shield.
Is that a temperature sensor?
Sorry, but there are major problems with both the recent climate data, and that which is retrieved through core samples. We know of data tampering on the continent, so I pay this zero attention.
tonyb says:
August 23, 2012 at 8:08 am
Is anyone looking for the cause?
Little doubt about that Tony, if the fluid far down below the Antarctica is so faithfully following the sun, I can’t see a solid reason why the fluid surrounding the Antarctica, which is directly exposed to sun (in more ways than one) should not do the same.
http://www.vukcevic.talktalk.net/SSN-dBzA1.htm
Unfortunately climate science at the moment is so preoccupied with CO2 as a toddler who discovered ‘sucking dummy’, an awful lot of chewing on no substance .
Hello Climatologists!!
Does the observation that bits of Antarctica were warmer than today 10,000+ years ago raise any interesting questions in your minds?
Here’s some that spring to mine:
– what caused the warmer climate to occur?
– what caused it to stop and cool down?
– if it cooled down until 600 years ago, what caused it to stop cooling and start warming again?
– how representative is Antarctica as a proxy for the rest of the globe? If you think it is a good one, how can you demonstrate it is? If not, how do you demonstrate that it is bad?
Seems to me that answers to these questions might be highly relevant to our understanding of past climates.
And given the timescales involved and the lack of increased CO2 due to fossil fuel burning at the relevant times, a thorough and demonstrable explanation of these pre-existing changes is essential groundwork before one can sensibly estimate any recent CO2 based contribution. It is not really good enough to assume that all of these other effects suddenly stopped in 1960 or thereabouts. You have to show that you have really got a handle on them first. IMO this work has yet to be done. Here is the opportunity.
Because of all of the artic melting and in the mountains, we will be flooded on earth and there will be catastraphic floods on the on all of the continents. That is why the Mississisppi river is shut down right now and vessels can NOT navigate the waters. The Great Lakes are down (at least Lake Michigan). We are in a terrible drought in the US. See what all the melting is doing.
Definitely check out the Supplemental, good stuff. The peninsula seems to be the austral Greenaland, a place where all trends are amplified and everything happens in a big way. The climb out of the LGM is practically vertical! Recent warming “not unprecedented”, you don’t say!
Interesting that more recent trends are antiphase with other Antarctic cores and that snow depth has increased exponentially in response to recent warming without apparently reacting to the prior maximum or the climb out of the LGM.
Interesting to think about what causes an unconformity in an ice core…
And ENSO is only 5000 years old? Tisdale will be pleased with the temperature response. I would have expected it is a lot older than that. Off to the ODP data on this one.
We know so little.
Read O’Connell et al. 2010 who sent Steig packing… The Peninsula is not Antarctica. As for today’s warming cause, this is dynamic warming as a result of increased warm air advection from more frequent and powerful MPHs and catabatic winds (Leroux). There was even some record snowfall on the peninsula as a result.
The warming started 600 years ago and is not unprecedented. But just wait, that’s not what we will hear from the hothead bloggers or the “science” journalists.
I’ve read that ice cores can’t be used to measure temperatures for the most recent 50, or 100, or 150 years, because the snow hasn’t compacted enough.
Latimer
I asked much the same questions just above your comment.Whilst I was therefore theoretically first I will gladly share with you and Vuk the £5 million research grant I am expecting any time soon from Big Oil or Big Wind in order to explore the basic question;
Why did it start warming 500 years ago?
tonyb
tonyb:
At August 23, 2012 at 8:08 am you ask
Your question shows you don’t understand global warming science. Obviously, the warming started because the penguins began operating their power station which is situated in the same place as Trenberth’s heat. And it must be there because nobody has found it and, therefore, there is no need to look for it.
(just in case, /sarc)
Richard
@Kadaka; “See the thing at the front left corner hanging off the roof of the building on a short mast? It doesn’t look like a light, there’s nothing else like it elsewhere around the building (that I can see).”
Surveillance camera housing?
High winds do not remove all contaminations. Radiative transfers are nearly unaffected by wind. Only conductive transfers are.
bug zapper?
From rogerknights on August 23, 2012 at 9:29 am:
The GISP2 reconstruction was extended by new techniques to much closer than 50 years.
GISP2 Ice Core 4000 Year Ar-N Isotope Temperature Reconstruction
Abstract and data:
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2-temperature2011.xls
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2-temperature2011.txt
Listing:
http://www.agu.org/pubs/crossref/2011/2011GL049444.shtml
Leif has a copy:
http://www.leif.org/EOS/2011GL049444.pdf
The freely-available archived data (first two links) go to 1993.
@tonyb
Very happy to concede precedence to you!
But worth noting as an excellent example of great minds thinking alike.
Would it be mischievous – as an aside from all the important stuff – to wonder what is the ‘consensus’ explanation for the considerable deviation between these results and the notorious hockey stick which told us once and for all and absolutely definitively that the warming only started a hundred years ago? There is a 500 year discrepancy that ain’t going to go away without some fancy footwork somewhere.
And can I draw your – and anybody else who’s interested’s – attention to a couple of climate science socials being organised by Bishop Hill’s courtiers in London and Oxford:
http://bishophill.squarespace.com/blog/2012/8/23/london-bh-pub-meet.html
All welcome of whatever persuasion within the climate world. Civility and good fellowship the only prereq.
After the last one Richard Betts, an IPCC lead author wrote
‘I came away feeling that the extreme polarisation of the climate debate in the last 10-15 years could have been avoided if only everyone had just gone down the pub together in 1998!’
The statement is made that “the rapid warming of this region over the last 100 -years has been unprecedented”
But wait a minute–later it says “the Antarctic Peninsula warmed by about 6°C as it emerged from the last ice age.” We know from ice cores that the last Ice Age ended VERY abruptly, warming as much as 15 °C in only 100 years. So how can warming in the past 100 years be “unpresedented?” What kind of double talk is this?
The implication is that the ANTARCTICA warmed by this amount, but the study is only for the Antarctic Peninsula, which holds a minor amount of the glacial ice in Antarctica and is surrounded by ocean water that has warmed recently (the Antarctic Peninsula warming is undoubtedly more a matter of the warmer ocean water surrounding the peninsula than general Antarctic atmospheric warming). In fact, the temperatures recorded at the South Pole and at Vostock since 1957 show NO WARMING at all for that past 55 years!
The bottom line here is that this study does NOT show that the Antarctica ice sheet is warming at all.
Latimer
Fashion and wishful thinking. It provided the answer required at the time to justify the continuance of the ipcc and the development of climate science.
Tonyb
Meanwhile back at the webcam pools shrinking fast.
August 19
http://psc.apl.washington.edu/northpole/NPEO2012/WEBCAM2/ARCHIVE/npeo_cam2_20120819004549.jpg
August 23
http://psc.apl.washington.edu/northpole/NPEO2012/18.jpg
Tony the answer is simple.
First penguin’s droppings that landed there, started the ever stronger methane positive feedback, a bit warmer, more penguins survive, more droppings, more methane, more warming, and so on and on. (sarc/ off)