From CO2 Science, another peer reviewed paper with a paleoclimatology reconstruction based on cores containing plankton shells, show that both the Medieval Warm Period (MWP) and the Little Ice Age (LIA) can be seen in Indonesia. In the past, critics have said these events to be “regional” implying they occurred only around Europe, due to lack of historical records in other regions of the world.
Since the Oxygen18 isotope dating method seems well proven, it would seem this study has a good basis for its claims. Even RC’s Gavin Schmidt likes it.
Co2 Science writes:
From the authors’ Figure 2b, adapted below, we calculate that the Medieval Warm Period was about 0.4°C warmer than the Current Warm Period.
The Makassar Strait (Wikipedia)
Foraminifera samples.
Description
Oppo et al. derived a continuous sea surface temperature (SST) reconstruction from the Indo-Pacific Warm Pool (IPWP), which they describe as “the largest reservoir of warm surface water on the earth and the main source of heat for the global atmosphere.” This history — which was based on δ18O and Mg/Ca data obtained from samples of the planktonic foraminifera Globigerinoides ruber found in two gravity cores, a nearby multi-core (all at 3°53’S, 119°27’E), and a piston core (at 5°12’S, 117°29’E) that were recovered from the Makassar Strait on the Sulawesi margin — spans the past two millennia and, as they describe it, “overlaps the instrumental record, enabling both a direct comparison of proxy data to the instrumental record and an evaluation of past changes in the context of twentieth century trends.” Reconstructed SSTs were, in their words, “warmest from AD 1000 to AD 1250 and during short periods of first millennium.”
Reference
Oppo, D.W., Rosenthal, Y. and Linsley, B.K. 2009. 2,000-year-long temperature and hydrology reconstructions from the Indo-Pacific warm pool. Nature 460: 1113-1116.
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Unlike plate tectonic theory – which brought together disparate material into a unified and explainable whole – global warming has required the discrediting of the Medieval Warm Period, the Urban Heat Island effect, and solar fluctuation in order to make its case. My scepticism has risen in direct proportion to the amount of past climate evidence that the AGWers have demanded be discarded.
Excellent account of the LIA and the superimposed (coincidental?) impact of Icelandic eruptions given by Prof Dawson in “So foul and Fair a Day”.
http://europe.theoildrum.com/node/6387
Some convincing evidence for natural climate cycles comes form Scott Stine’s description of Owen’s Lake (California) being dry 800 years ago. It filled up with water during the LIA, a nice environment for those escaping Hell in Europe to settle.
I think its safe to say anyone who does not have an axe to grind knows that the current warming is not unprecedented.
Also proofs of the same from south america:
http://www.springerlink.com/content/m11m129238u61484/
euan mearns (12:16:26) :
The same case of a dry lake being filled durin the Maunder Minimum:
To the last two peaks of large inflow of meltwater, radiocarbon dates corrected to sidereal ages, are AD 1280/1420 and AD 1443/1656. These ages agree with two cold episodes clearly recorded in dendrological studies from the Patagonian Andes and were correlated to the Little Ice Age. Thus, older Holocene episodes of large inflow of water to the basin were correlated with the Neoglacial Advances defined by Mercer (1976) for the Andes.
http://www.springerlink.com/content/m11m129238u61484/
(cited above)
I read that way of thinking a lot, but It doesn’t make sense under the scientific point of view. If you claim that The MWP and the LIA were regional, you have to prove it, otherwise it shouldn’t be a scientific argument.
The obvious question now-in these “interesting times”- is: Are solar minimums (minima) ,low solar magnetic field epochs, related to volcanic eruptions-lowering temperatures-/big earthquakes ?
@John Egan: I wouldn’t bring plate tectonics into this. It’s a very whacky idea that gained prominence because the older theory couldn’t explain the mechanism. Plate tectonics has changed explanations countless times on its own mechanics and will change again. If you look at the geometry, PT is physically impossible for long distances. In fact, PT fell out of favour with the people responsible for bringing it to prominence. Also, subduction doesn’t exist on other planets. And it doesn’t exist on Earth either even though plenty of “scientists” will try to claim otherwise.
Oxygen 18
http://earthobservatory.nasa.gov/Features/Paleoclimatology_OxygenBalance/
A quick explanation
Peer-reviewed to boot!
(Not that it’s important anymore – at least not for the IPCC),
FoxNews covers the IPCC’s F-graded report.
http://www.foxnews.com/scitech/2010/04/19/united-nations-climate-global-warming-ipcc/
Concerning MWP, it was consensus that it existed – until the Hockey-Stick Bros. came around and tried to airbrush it out.
This is yet another arrow through the heart of the bogus AGW tales.
Make that 501
http://www.populartechnology.net/2009/10/peer-reviewed-papers-supporting.html
blacks whitewash (12:17:48) :
I think its safe to say anyone who does not have an axe to grind knows that the current warming is not unprecedented.
—-
Indeed. Ever since this all started being about axe-grinding agendas I have relied on this little summary as a guide. Yes, from Nature, but back when it wasn’t compromised by politics, and also in a paper not directly dealing with climate change per se.
I must ask this extremely well informed group commenting here if this still rings true or whether new research has somehow changed this:
“The Greenland (Arctic) and Vostok (Antarctic) ice cores are particularly informative, offering fine temporal resolution and continuity. This has revealed surprising oscillations of climate on a millennial scale within the main 100-kyr cycle. The Greenland Ice Core Project (GRIP) identifies some 24 interstadials through the last ice age with average temperature rising rapidly by ~7 C over just decades. Further ice and sediment cores from around the world are demonstrating the global scale of these major climatic events.”
From: Hewitt, G. 2000. The genetic legacy of the Quarternary ice ages. NATURE, Vol. 405, 22 June 2000 (www.nature.com)
Again: “with average temperature rising rapidly by ~7 C over just decades.”
So did the IPCC gang rebore the ice and find something different?
Do you think we could get a key or legend describing the different coloured lines in the graph??
Woah! Lets not get too excited… these are “proxies” aren’t they?!? Or are there “good proxies” and “bad proxies”???
Yep, it’s definitely getting tougher for those deniers of MWP and LIA. btw, C3 put up a purrr-ty version of same chart, which was on their site earlier in the day.
http://www.c3headlines.com/2010/04/new-climate-data-reveals-modern-warming-to-be-only-lukewarm-versus-medieval-roman-periods.html
MrX (12:34:53) :
“I wouldn’t bring plate tectonics into this. It’s a very whacky idea …”
Oh yeah? Got a better theory?
With all the proof, this is our real problem according to Joe Bastardi for his latest blog post:
“It does show the folly of man thinking he has all these grand plans and is in control. But in the battle, and with the latest NOAA release upping the ante even more than man is causing all this
( it’s open season in spite of all we have seen, the ice cap returning, the leveling of temps, Climate Gate… my prediction this Congress would be right back at it with the Cap and Trade after they got health care, though not meteorological, is spot on. see this: http://www.alertnet.org/thenews/newsdesk/N19159977.htm )
we find that nothing will stop the zealots. They even go so far as to blame global warming for volcanoes. There are no limits, and a willing public, many of them under 40 and knowing no better than what they have been told the last 20 years, is not willing to dig in and look”.
http://www.accuweather.com/ukie/bastardi-europe-blog.asp?partner=accuweather
blacks whitewash (12:17:48) :
I think its safe to say anyone who does not have an axe to grind knows that the current warming is not unprecedented.
Hey there, climategatestuff aka blackwhitewash! Where you been?
Nah, the Mann-made disinformation campaign has run a long time, gone very deep, and is still spreading wide. It’s going to take awhile to get the truth out to the innocently deceived, of which our school systems are currently programming even more as we speak. Then we have the assorted types of the brainwashed to deal with, from the forcefully indoctrinated (“They kept sending me to Save-the-Earth seminars!”) to the willfully-following (“Now I understand why everyone deserves to die.”)
Yup, we got a job ahead of us.
I’ve never understood how anyone could believe that when it was warm enough to support farming in Greenland over the course of two or three centuries, this was just a local condition.
Or maybe no one really believes it. If they did, they’d be queueing up around the block with fancy models to explain an effect like that.
Urederra (12:29:54) :
“… If you claim that The MWP and the LIA were regional, you have to prove it, otherwise it shouldn’t be a scientific argument.”
Actually, this amounts to a classical falsifiable hypothesis. The accumulating evidence of correlated warm episodes in other parts of the world falsifies the regional limitation.
“Oxygen18 isotope dating method”
Novel! I prefer to use radiocarbon for dating.
[sarc]
Since this wasn’t reviewed by the relevant people it is irrelevant …
[/sarc]
MrX (12:34:53) :
@John Egan: I wouldn’t bring plate tectonics into this. It’s a very whacky idea that gained prominence because the older theory couldn’t explain the mechanism. Plate tectonics has changed explanations countless times on its own mechanics and will change again. If you look at the geometry, PT is physically impossible for long distances. In fact, PT fell out of favour with the people responsible for bringing it to prominence. Also, subduction doesn’t exist on other planets. And it doesn’t exist on Earth either even though plenty of “scientists” will try to claim otherwise.
Well. There you go. Everything I was taught in school, out the window in one fell swoop.
Thanks, MrX, for enlightening us. I guess it’s time to start all over from square 1. In the meantime, how about providing some proof of your hypothesis? It should be an interesting read.
Are there any climate changes that cannot be explained by a simple cyclical oscillation of all the air circulation systems latitudinally ?
@Duster
I know. What I mean is that it cannot be said that MWP and LIA are regional phenomena without proving it. And somehow the proponents of the AGW theory haven’t done much to prove it, other than saying “nope, that’s regional”