Sorry no graphics, no abstract or paper (not published yet, due Friday the 27th, I hate it when they do this) the Penn State press release was rather spartan. So I’ll provide this one showing Mann’s previous work where the Medieval Warm Period doesn’t much show up at all:
So here’s the question, the press release below mentions sediments. Place your bets now on whether the Tiljander sediment series remains inverted or not. (h/t to Leif Svalgaard) – Anthony
Past regional cold and warm periods linked to natural climate drivers
Intervals of regional warmth and cold in the past are linked to the El Niño phenomenon and the so-called “North Atlantic Oscillation” in the Northern hemisphere’s jet stream, according to a team of climate scientists. These linkages may be important in assessing the regional effects of future climate change.
“Studying the past can potentially inform our understanding of what the future may hold,” said Michael Mann, Professor of meteorology, Penn State.
Mann stresses that an understanding of how past natural changes have influenced phenomena such as El Niño, can perhaps help to resolve current disparities between state-of the-art climate models regarding how human-caused climate change may impact this key climate pattern.
Mann and his team used a network of diverse climate proxies such as tree ring samples, ice cores, coral and sediments to reconstruct spatial patterns of ocean and land surface temperature over the past 1500 years. They found that the patterns of temperature change show dynamic connections to natural phenomena such as El Niño. They report their findings in today’s issue (Nov. 27) of Science.
Mann and his colleagues reproduced the relatively cool interval from the 1400s to the 1800s known as the “Little Ice Age” and the relatively mild conditions of the 900s to 1300s sometimes termed the “Medieval Warm Period.”
“However, these terms can be misleading,” said Mann. “Though the medieval period appears modestly warmer globally in comparison with the later centuries of the Little Ice Age, some key regions were in fact colder. For this reason, we prefer to use ‘Medieval Climate Anomaly’ to underscore that, while there were significant climate anomalies at the time, they were highly variable from region to region.”
The researchers found that 1,000 years ago, regions such as southern Greenland may have been as warm as today. However, a very large area covering much of the tropical Pacific was unusually cold at the same time, suggesting the cold La Niña phase of the El Niño phenomenon.
This regional cooling offset relative warmth in other locations, helping to explain previous observations that the globe and Northern hemisphere on average were not as warm as they are today.
Comparisons between the reconstructed temperature patterns and the results of theoretical climate model simulations suggest an important role for natural drivers of climate such as volcanoes and changes in solar output in explaining the past changes. The warmer conditions of the medieval era were tied to higher solar output and few volcanic eruptions, while the cooler conditions of the Little Ice Age resulted from lower solar output and frequent explosive volcanic eruptions.
These drivers had an even more important, though subtle, influence on regional temperature patterns through their impact on climate phenomena such as El Niño and the North Atlantic Oscillation. The modest increase in solar output during medieval times appears to have favored the tendency for the positive phase of the NAO associated with a more northerly jet stream over the North Atlantic. This brought greater warmth in winter to the North Atlantic and Eurasia. A tendency toward the opposite negative NAO phase helps to explain the enhanced winter cooling over a large part of Eurasia during the later Little Ice Age period.
The researchers also found that the model simulations failed to reproduce the medieval La Nina pattern seen in the temperature reconstructions. Other climate models focused more specifically on the mechanisms of El Niño do however reproduce that pattern. Those models favor the “Thermostat” mechanism, where the tropical Pacific counter-intuitively tends to the cold La Niña phase during periods of increased heating, such as provided by the increase in solar output and quiescent volcanism of the medieval era.
The researchers note that, if the thermostat response holds for the future human-caused climate change, it could have profound impacts on particular regions. It would, for example, make the projected tendency for increased drought in the Southwestern U.S. worse.
Other researchers on the project were Zhihua Zhang, former postdoctoral fellow in meteorology now at the National Oceanic and Atmospheric Administration; Scott Rutherford, Roger Williams University; Raymond S. Bradley, University of Massachusetts; Malcolm K. Hughes and Fenbiao Ni, University of Arizona; Drew Shindell and Greg Faluvegi, NASA Goddard Institute for Space Studies, and Caspar Ammann, National Center for Atmospheric Research.
The National Science Foundation, the U.S. Department of Energy, NOAA, and NASA supported this work.
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Anthony,
A quick one, if Greenland was warmer but the Pacific colder, then one way of doing that is to re-orient the Earth’s rotational axis by an EM (non gravity) interaction by the Earth with an interloper.
The trouble with working out palaeo climates is defining a 3-D benchmark for the Earth’s celestial orientation over time. No one on Earth could have done this, yet we have to physically account for the Egyptian records that report the sun rising in the west while it, before, the east.
I err – Earth based scientists could have by observing astronomical data, but then those observations assume the Lyellian paradigm that since Creation, nothing much has changed.
After a quick look at the paper:
good point: seems to provide all (at least a bunch) data and code and method (22 Meg of compressed data and stuff as supplementary info). Even if it may contain errors or so, I think it is a progress.
Bad point: hide the decline… more … (figure 1) proxies reconstruction stops in 1850 (about) then go to only instrumental record. I don’t know yet if there is a reason why explained in the paper. To be checked further.
ha, and I am always impressed that error interval is the same in 1800 and around than in 500, begining of the reconstruction, and all along the reconstruction… reminds me of my first year of study, when calculating errors was the very annoying point of the experiment, just add +/- 1 to all data points.
Your Global Warming Thanksgiving 🙂
http://biggovernment.com/2009/11/26/your-global-warming-thanksgiving/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+BigGovernment+(Big+Government)
This is what is really going on with climate (I think):
http://climaterealists.com/attachments/database/The%20Missing%20Climate%20Link.pdf
1047485263.txt and 1062618881.txt
Around the 2003 time frame, Michael, Scott, Tom, Phil, Malcolm, Raymond, Keith, and another Tom, get together to redefine the WMP and LIA, and the dates these occurred.
Phil says:
” I agree with all the points being made and the multi-authored article would be a good idea, but how do we go about not letting it get buried somewhere. Can we not address the misconceptions by finally coming up with definitive dates for the LIA and MWP and redefining what we think the terms really mean? With all of us and more on the paper, it should carry a lot of weight. In a way we will be setting the agenda for what should be being done over the next few years.”
Interesting.
Quite evidently the intention is to make the MWP and the LIA and similar events out to be purely local phenomena.
There has been some debate about the extent of these events before but if the Michael Mann says these are regional variations, then we can safely ignore them and he is exonerated for leaving them out of his earlier charts/data. Of course, if it were true, he would have had to have known this before he published his earlier works, not wait till now.
Of course, there is one interesting point.
If these were purely regional phenomena and had no overall or significant global effect then we won’t see them in the CO2 records, will we?
That is to say, if the warming of the climate translates into warmer oceans which then release CO2 and similarly if cooling allows more CO2 to be taken up by the oceans (the CO2 change following temperature) then we will only see the CO2 signature of the MWP and the LIA if they are significant and global in impact.
Hmm. And what do we find?
@ur momisugly Robinson (01:14:21) “news, a new hatchet job on “climate contrarians” has appeared in The Telegraph. ”
Wow! That’s quite a stunning piece of propaganda (by an apparently unattributed writer) in the Telegraph Blog. It appears to be nothing other than a list of who you really must hate if you wish to be a true AGW believer.
Its fascinating the way it starts with a bogeyman in the form of a silly photo of a windblown George W. Bush, which the writer designates as: “arguably the greatest global warming sceptic of all time” ! If that was true it would sure raise him up a few notches in my estimation.
It would be interesting to know who concocted this list. It does look like a rather desperate press release to rally the faithful and I wonder will it appear in similar forms in other MSM sites?
Apologies if someone has already pointed this out but this is complete nonsense
“The researchers found that 1,000 years ago, regions such as southern Greenland may have been as warm as today”
Southern Greenland was FAR WARMER 1000 years ago than it is today. Those fields the Vickings plowed are under hundreds of feet of ice.
Don’t they have editors?
Has anyone noticed that Mann’s proposed paper is pretty much a ‘copy’ of my writings over the past year and a half save that he still thinks the air warms the oceans and not vice versa ?
I can see in the additional document (access freee PDF), that they still show temperature curves using proxies before 1850 with a 95% confidence interval, and the instrumental temperature record after 1850…without any confidence interval.
This is an obvious trick, as usual. Proxies should be used all the way, it is misleading to interrupt a time serie and continue with another. And where is the temperature record uncertainty? We all know temperatures are adjusted like proxies, days are missing, records cover only small areas of earth. Uncertainty should be there this is unacceptable!
It would be great if someone could use the data joined with this article to draw a temperature reconstruction chart using proxies before AND after 1850.
I don’t have matlab and can’t use it, but I can see in the spatial reconstruction they still have data after 1850 coming from proxies (?)
“The spatial reconstruction. Column 1 is year, columns 2-2593 are gridboxes. Years 1850-2006 are the PC-filtered instrumental data(retaining 7 PCs). (note this is a large file and has been gzipped)”
Of course, I’m a big believer in the natural variability provided by the ENSO and the North Atlantic (which can be about +/- 0.5C to 0.6C together – but is more often much less than these two extremes).
Mann has actually written papers about these before. Phil Jones recently co-authored a paper using the ENSO and a new measure they created for the influence of the North Atlantic (which is just a white noise series that has no impact).
So Mann’s sole purpose, like Phil Jones, is a pre-emptive strike. Get out in front of other researchers trying to go farther back in time looking at the ocean cycle influences, and come up with some “modest” cycles, that are much, much smaller than the current warming of course using some sort of “new math”.
It is predictable.
Will: “I have just noticed on YouTube that the video featuring Mann in “Hide the decline” http://www.youtube.com/watch?v=nEiLgbBGKVk has been removed from the “Most Viewed List”.
It was in the top 10 earlier today and with 163000 views should now be at the top.
What goes on ?”
It quite clear what’s going on! Google is part of the Alarmist movement and is diddling with the presentation of information to suit THEIR purposes. They’ve also been doing it with their search engine to minimize the search exposure of Climate Gate.
Anthony,
The Vikings were successfully farming (not just grazing sheep) in Southwest Greenland during the Medieval Warm period. I challenge anyone doubting it was warmer then than now to go over there and give it a try.
In reading the Paleoclimate chapter in the IPCC Fourth Assessment Report (AR4): I think it’s important for your readers to understand that Mann & Jones are at the heart of it and thus the upcoming meeting in Copenhagen. Also, in the public statements you cite from East Anglia U. and CRU note their emphasis to serving global warming public policy rather than a commitment to unbiased science. If the IPCC and others begin to question their data-goodbye to their funding. Makes sense.
Thanks for your web site!
Jet Halon
AGW: The Road to Erewhon*: A correlation?
Harvard: Liberal Iffy Ignatieff and O’s Harvard Crimson: Red-Green Magical Mann-Holdren Fraud.
…-
“What was so blasphemous about their paper?”
“A Blast From the Past
A Harvard Crimson article from 2003 described what fate befell two Harvard scientists who dared to challenge Global Warming.
A study by two Harvard researchers quietly published last January in a small research journal has set off a political storm that has led to debate on the senate floor and internal wrangling at the Environmental Protection Agency (EPA). The study, co-authored by two scientists at the Harvard-Smithsonian Center for Astrophysics, concluded that the 20th century has been neither the warmest century of the past millennium nor the one with the most extreme weather.
The two scientists were subsequently excoriated in the strongest terms by Michael Mann and John Holdren, now Barack Obama’s science czar. The Crimson describes the reception they got.”
“What was so blasphemous about their paper?”
>>> “Cambridge, MA – A review of more than 200 climate studies led by researchers at the Harvard-Smithsonian Center for Astrophysics has determined that the 20th century is neither the warmest century nor the century with the most extreme weather of the past 1000 years. The review also confirmed that the Medieval Warm Period of 800 to 1300 A.D. and the Little Ice Age of 1300 to 1900 A.D. were worldwide phenomena not limited to the European and North American continents. While 20th century temperatures are much higher than in the Little Ice Age period, many parts of the world show the medieval warmth to be greater than that of the 20th century.”
http://pajamasmedia.com/richardfernandez/2009/11/26/a-blast-from-the-past-3/#comments
…-
WUWT?
>>> “Mann has a new paper: he apparently discovers the Medieval Warm Period”
>>> “I’ll provide this one showing Mann’s previous work where the Medieval Warm Period doesn’t much show up at all:”
http://wattsupwiththat.com/
…-
*Erewhon – Google Books Result
by Samuel Butler – 2002 – Fiction – 192 pages
Erewhon (an anagram for “nowhere”) is a faraway land where machinery is forbidden, sickness is a punishable crime, and criminals receive compassionate medical …
books.google.ca/books?isbn=0486420485
Unabomber & Maurice Strong’s Manifesto: Red-Green.
Erewhon: “a faraway land where machinery is forbidden”.
How I read this is not that Mann has discovered the medieval warm period, but that he cannot get rid of it and instead calls it an anomaly and ignores the warmth of that period with claims that climate was not global back then. They had long-term regional weather instead!
It will take a lot more baby steps like that for him to extricate himself from the biggest scientific fraud of the last 200 years!
Dear Anthony,
for a recent article I have prepared a map of locations showing evidence for the MWP. Maybe you find that helpful. (here is a Goole translation of the according article)
(exasperated sigh)
Will someone PLEASE explain the principle of teleconnection to Prof. Mann?
Jeff
SABR Matt (20:59:27):
I will say this one more time.
If the tropical Pacific cools when the northern climes warm…that means the Earth’s energy budget system NORMALIZES itself. It means there is NO THREAT of runaway warming…it means warm forcing has NEGATIVE FEEDBACK…and it means the AGW crowd has been crowing about NOTHING for years.
As I understand it a ‘feedback’ would be something that alters the total heat content of the system – you’re just talking about redistributing it (by bringing colder water up from the deep ocean). The increased heat resulting from an enhanced greenhouse effect would in that event be going into the deep ocean and would manifest itself as La Niña events having less of an impact in future years. Unless you can suggest a mechanism by which this redistribution of heat actually causes an increase in top-of-atmosphere radiation, you can’t really be challenging AGW on this basis.
This is a Gonzo Scheme,as opposed to a Ponzi. Scientists becoming the authors of the story,not just reporters and allying with big money,Governments and media. .This is manipulation of the masses on a giagantic scale. If it’s possible to donate to the Nippc as mentioned by professor Singer in the video above,that’s where my charity money is going this year.As things progress and it becomes apparent that the BBC had a written policy that the ‘Science is settled’ and AGW sceptics were not to be given equal airtime,this organ of the State will be severely and permanently damaged.Really a wonderful result for independent thought!
Steve has a blog post on this. He says he’s speechless. I find that very hard to believe, after all that’s happened!
“…if you question the reliability of paleoclimate data, or say that it’s been “inverted,” what’s YOUR basis for estimating the magnitude of the medieval warm period?”
Who has questioned the reliability of all paeleo-evidence?
Besides, there are written accounts, e.g. of the Viking settlements, and also archaeological evidence of human activities that would be weather -dependant? Pass that bottle of Chateau Labrador, vintage 1050.
Also, c. 1000, the Vikings were regularly sailing through the Arctic Ocean, in the process of colonizing the river valleys of Russia and Ukraine.
Just a wicked, wee thought.
I just googled “Google ClimateGate”, the quotes are essential, and got 223 results.
Given that this forum gave birth to the name, well done daddy BullDust, does anyone have any ideas how to push this number up?
Maybe this is a pointless and stupid idea anyway but it’s what the warmists have been doing for years!
It may provide a bit of fun in the days leading up to Wonderful Copenhagen and who knows it may help to educate some.
“Off-topic, I know. But you may be amused by this:
Gore Flees in Panic from Chicago Book Signing”
When I said that I was waiting for Lyndon LaRouche, I thought I was kidding.
Who’s next up, David Duke?
This is why I respect L
SvaalgardSvalgaard. If I am correct he has no opinions about AGW ect or he may even be a complete AGW’er or not but his transparency is what is credible and I fully respect that. I wish “the team” had been like that. The truth will win in the end. That is all that matters.REPLY: VG his name is spelled “S v a l g a a r d” just so you know. I fixed above. – Anthony