“… abrupt climate change has been a systemic feature of Earth’s climate for hundreds of thousands of years…”
From Cardiff University
800,000 years of abrupt climate variability
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 volcanic eruptions. 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 temperature record 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 (8 September) demonstrates that abrupt climate change 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 climate variability.
The collaborative research was funded in part by a Leverhulme Trust Philip Leverhulme Prize awarded to Dr Barker at Cardiff University. The prize recognises the achievement and potential of outstanding researchers at an early stage in their careers but who have already acquired an international reputation for their work. The Natural Environment Research Council and National Science Foundation in the United States also funded the research.
Website: www.cardiff.ac.uk
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What, no graphs? Lots of spin, little meat. How well do Antarctic and Greenland records correspond, anyway? At least Barker mentions the need for validation, but there’s nothing about when these “longer Greenland records” might be produced.
Shhh, Katherine, don’t jinx the process…they’re talking about natural and abrupt climate change! Don’t want NEC and NSF to realize their mistake! /sarc
So, these guys used a model to produce “a prediction of what climate records from Greenland might look like over the last 800,000 years”.
Katherine asks:
“How well do Antarctic and Greenland records correspond, anyway?”
Short answer – they don’t!
There are significant, unexplained phase differences. In addition, the available data can be interpreted several different ways. In one scenario, Greenland was almost ice free during the peak of the last ice advance. In fact, the evidence is quite strong that the current ice cap did not form until after the ice sheets began to retreat. (There are other interpretations of the data.)
Meanwhile, The Age reports on the “dramatic shrinking” of Greenland. Might it be possibly be natural, Fairfax?
http://www.theage.com.au/environment/climate-change/dramatic-shrinking-of-greenland-glacier-20110908-1jyym.html
I am sure politicians and pretend scientists had a quick fix back 800M ago also. ….Oh wait…
This research is building on the known see-saw effect of alterations in the Atlantic ocean currents of the MOC.
Ice core data show that cooling in the Arctic is accompanied by warming in the Antarctic. This research roots that in changes in ocean circulation. –
“Dr Stephen Barker, Cardiff University’s School of Earth and Ocean Sciences and lead author on the paper, said: “During this period very large and abrupt changes in temperature were observed across the North Atlantic region. …
The new study suggests that abrupt changes in the north were accompanied by equally abrupt but opposite changes in the south. It provides the first concrete evidence of an immediate seesaw connection between the North and South Atlantic. The data shows, for example, that an abrupt cooling in the north would be accompanied by a rapid southerly shift of ocean fronts in the Southern Ocean, followed by more gradual warming across the south.
Dr Barker explains: “The most intuitive way to explain these changes is by varying the strength of ocean circulation in the Atlantic. By weakening the circulation, the heat transported northwards would be retained in the south.”
The significance of this is that past natural climate change has included very rapid events (A1 meltwater pulse) which can happen as small forcings alter the climate if Atlantic ocean currents are altered.
It indicates that similar events in response to the warming from the extra energy retained by the increasing CO2 are not impossible, and very rapid change cannot be excluded from the potential effects of AGW.
The problem I have with the CO2 story is that ice ages always start (last 800 000 years) with CO2 levels high and temperature high. And when temperature is extremly low and CO2 level can not support terrestrial plant life anymore (lower as 200 ppm ) temperature suddenly goes up.
Don’t they tell us this should be the other way round.
http://www.eea.europa.eu/data-and-maps/figures/antarctic-temperature-change-and-atmospheric-carbon-dioxide-concentration-co2-over-the-past-800-000-years
“At year 18,000 and counting in our current interglacial vacation from the Ice Age, we may be due– some say overdue– for return to another icehouse climate!”
http://www.geocraft.com/WVFossils/last_400k_yrs.html
Katherine, you didn’t read it properly. They have produced
.
SO of course no graphs yet – they;re just predicting what the records will look like when they get round to producing them.
Cardiff says, “…scientists have reconstructed an incredible record…”
Incredible, eh? Their honesty is to be applauded. But they should be working on their credibility.
It’s a model, it might be a model we like, but it is still a model and until we see the empirical evidence backing it up we should all be sceptical.
@- Robertvdl says:
September 12, 2011 at 1:46 am
“The problem I have with the CO2 story is that ice ages always start (last 800 000 years) with CO2 levels high and temperature high.”
For the last 3 million years ice ages have been ended by increased solar energy recieved by the northern hemisphere in spring as a result of the axial and orbital variations – the Milankovitch cycles. CO2 is a FEEDBACK on this initiating factor.
-““At year 18,000 and counting in our current interglacial vacation from the Ice Age, we may be due– some say overdue– for return to another icehouse climate!””
Going by the Milankovitch cycle its at LEAST 30kyrs until the next glacial maximum. But there is a element of truth to the claim we chould be entering a new ice-age soon. In most previous interglacial periods after the (very!) rapid warming the climate cools again within a few thousand years. Not to the level of the glacial maximum, but to an intermediate level.
However in this interglacial period after a conventional fall in temperatures after the melt maximum ~8000 years ago it has recently started to warm BACK to those post-melt highs, behavior NOT seen in the 800,000 years of past glacial cycles seen at your link.
“… ice core temperature record retrieved from Antarctica and uses a mathematical formulation to extend the Greenland record beyond its current limit.”
Uhm, that’s a model isn’t it ?
“The new predictions provide an extended testing bed for the climate models that are used to predict future climate variability.”
Uhm, so the extended ice core ‘model’ gives them predictions (guesses) to ‘test’ the predictions from the climate models ?
Oh, I get this game …
Why wouldn’t you want to become a climate ‘scientist’ ?
Chrs JJ. Thanks Anthony, mods and posters.
The Greenland ice core records provide temperature data over the last few 10,000s of years. They clearly show the temperature peaks of the Minoan Warm Period, the Roman Warm period and the Medieval Warm period.
http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png
The Vostok ice core record from Antarctica provides a temperature (also CO2 concentration) map over a much longer period, about 400,000 years. The Vostok record is derived from an ice core drilled over 3km deep into the Antarctic ice sheet. It clearly shows the regular succession of ice ages interspersed with inter-glacial periods about every 100,000 years.
http://commons.wikimedia.org/wiki/File:Vostok-ice-core-petit.png
[Notice the excellent correlation between CO2 level and temperature in this graph]
We can see from this ice core record that our present inter-glacial, the Holocene, is no warmer than previous ones. In fact, according to the IPCC, it is not yet as warm as the Eemian, 100,000 years ago, Moreover, the IPCC’s Arctic Impact Assessment Report states that “the last interglacial was slightly warmer everywhere than at present…during the Eemian the winter sea-ice limit in Bering Strait was at least 800 km farther north than today, and that during some summers the Arctic Ocean may have been icefree.The northern treeline was more than 600 km farther north”.
Inter-glacial periods tend to last between 15,000 and 20,000 years. We have been in the present one for about 18,000 years. So, as Professor Svensmark says “Global Warming – enjoy it while you can”.
Robertvdl says:
September 12, 2011 at 1:46 am
The problem I have with the CO2 story is that ice ages always start (last 800 000 years) with CO2 levels high and temperature high. And when temperature is extremly low and CO2 level can not support terrestrial plant life anymore (lower as 200 ppm ) temperature suddenly goes up.
Don’t they tell us this should be the other way round.
————
Hmmmm. So Robert your saying a bunch of protohumans were burning massive amounts of fossil fuels 800000 years ago?
Jack Jennings says
Uhm, so the extended ice core ‘model’ gives them predictions (guesses) to ‘test’ the predictions from the climate models ?
Oh, I get this game …
———–
Nah , you still have not figured out the rules of the game. The prediction will be compared to ice cores from Greenland that they extract in the future.
Professor Barker’s team made a prediction based on a model. He then says we have to wait for data to see how the prediction holds up.
Shouldn’t we applaud his intent to test model results with real data?
@- Scottish Sceptic says:
September 12, 2011 at 2:48 am
“It’s a model, it might be a model we like, but it is still a model and until we see the empirical evidence backing it up we should all be sceptical.”
Is it a model ?
I can find no mention of a model in the press release or abstract.
What has been done is to look at the overlapping records at Greenland and Antarctica and identify the see-saw relationship with cooling in the north accompanied by warming in the south.
A mechanism for this pattern is hypothesised, the alteration in the Atlantic MOC, and the prediction made that when (efforts are ongoing) the Greenland record is extended further back the same see-saw pattern will be seen; BECAUSE the same cause, variations in the Atlantic MOC are the cause of the very rapid climate changes seen in the Northern hemisphere.
We have very detailed multiproxy records of climate oscillations in the last 20k years. Greenland isotopes is only one of them. Problems arize though when just about all other records tell another story. One example is the much ignored Hubberten et al 2004
http://www.uib.no/People/ngljm/PDF_files/Hubberten_et_al_2004,_QSR.pdf
Now just goto page 8 / 1340
“Most of the Late Weichselian (Sartanian), namely
from about 24 to 15 ka BP, was characterizedby the
lowest levels of xerophilic insects, virtual disappearance
of steppe species, and dominance of Arctic tundra
inhabitants (Fig. 6). That definitely indicates lower
summer temperatures than in the Middle Weichselian,
but still warmer temperatures than today.”
Obviously when the last glacial maximum here had warmer summers than today, what then can be true of the isotope thermometer of Greenland? And there is plenty plenty more where this is coming from.
“The new predictions provide an extended testing bed for the climate models that are used to predict future climate variability.”
Ah, I wondered why there was no mention of C02, but now I see this “research” is all in defense of the sacrosanct C02-based climate models. More CAGW pseudoscience, driven by prize money from some Trust, and funding by NERC and NSF.
“”””” The team’s reconstruction is based on the much longer ice core temperature record retrieved from Antarctica and uses a mathematical formulation to extend the Greenland record beyond its current limit. “””””
That word “current” is superfluous. The Greenland ice core record IS at its limit, so far as we know.
So does this new “Climate Guesser” circuit also work to guess the previous climate on Venus and Mars as well, or is it strictly limited to guessing earth climate.
So now that they can guess the Greenland ice core climate record back to 800,000 years, why not guess the Antarctic ice climate record back to say8 times its present limit, or 6.4 million years ?
Talk about arm chair science. Now we don’t actually have to observe anything in these inhospitable places, but we can just sit at home and guess the data. Nyquist must be rolling in his grave.
The links in the above article is to the Cardiff main page.
The link to the article on Greenland Ice is at:
http://www.cardiff.ac.uk/news/articles/800000-years-of-abrupt-climate-variability-7263.html
Dr. Richard B. Alley has in the past also made the same comment, that climate changes can be abrupt, happening within a decade. He even has a book on it. http://press.princeton.edu/titles/6916.html
In a Scientific American piece back in 2004 this is discussed…where, of course, global warming makes it even worse… and in that paper Alley’s study is referenced. ..”Intense, abrupt warming episodes appeared more than 20 times in the Greenland ice records…
ref:
Abrupt Climate Change: Inevitable Surprises. National Research Council, Committee on Abrupt Climate Change. Richard B. Alley, chair. National Academy Press, 2002.
and:
“Greenland Ice Cores: Frozen in Time,” by Richard B. Alley and Michael L. Bender; Scientific American, February 1998]
http://www.chicagocleanpower.org/alley.pdf
…let’s keep in mind that Alley is at Penn State….
It is clear that none of the previous comments made have read, let alone understand the Barker paper. Try reading it first. It is in the current issue of Science Express (AAAS). These comments lower the standard of `What`s Up`.
It is clear that none of the previous commentators have read, let alone understood the Barker paper. Try reading it first. It is in the current issue of Science Express (AAAS). These comments lower the standard of `What`s Up`.
Well, if the ice and climate could change quickly and massively without humans around, just imagine how bad it’ll be with us driving climate change on top of it! It’s worse than we thought!!!
You just know that’s how this will be reported.