WUWT readers may recall yesterday where Dr. Mann was so eager to list this paper on his resume/CV, he broke the embargo set for 15:00 EST June 20th, today, at which time this blog post appears.
As much as this is an editorial target rich environment, I’m going to publish this press release and paper sans any editorial comment. There’s plenty of time for that later. Let’s all just take it in first. Below, figure 2 from the Kemp et al 2011 paper. It should look familiar. Note the reference in Figure 2 to GIA (Glacial Isostatic Adjustment) adjusted sea level data, which has recently been the subject of controversy, it was first noted here on WUWT.
First the press release:
Contact: Evan Lerner
215-573-6604
Penn researchers link fastest sea-level rise in 2 millennia to increasing temperatures
PHILADELPHIA — An international research team including University of Pennsylvania scientists has shown that the rate of sea-level rise along the U.S. Atlantic coast is greater now than at any time in the past 2,000 years and that there is a consistent link between changes in global mean surface temperature and sea level.
The research was conducted by members of the Department of Earth and Environmental Science in Penn’s School of Arts and Science: Benjamin Horton, associate professor and director of the Sea Level Research Laboratory, and postdoctoral fellow Andrew Kemp, now at Yale University’s Climate and Energy Institute.
Their work will be published in the journal Proceedings of the National Academy of Sciences on June 20.
“Sea-level rise is a potentially disastrous outcome of climate change, as rising temperatures melt land-based ice and warm ocean waters,” Horton said.
“Scenarios of future rise are dependent upon understanding the response of sea level to climate changes. Accurate estimates of past sea-level variability provide a context for such projections,” Kemp said.
In the new study, researchers provided the first continuous sea-level reconstruction for the past 2,000 years and compared variations in global temperature to changes in sea level during this time period.
The team found that sea level was relatively stable from 200 B.C. to 1,000 A.D. During a warm climate period beginning in the 11th century known as the Medieval Climate Anomaly, sea level rose by about half a millimeter per year for 400 years. There was then a second period of stable sea level associated with a cooler period, known as the Little Ice Age, which persisted until the late 19th century. Since the late 19th century, however, sea level has risen by more than 2 millimeters per year on average, which is the steepest rate for more than 2,100 years.
To reconstruct sea level, the research team used microfossils called foraminifera preserved in sediment cores from coastal salt marshes in North Carolina. The age of these cores was estimated using radiocarbon dating and several complementary techniques.
To ensure the validity of their approach, the team members confirmed their reconstructions against tide-gauge measurements from North Carolina for the past 80 years and global tide-gauge records for the past 300 years. A second reconstruction from Massachusetts confirmed their findings. The records were also corrected for contributions to sea-level rise made by vertical land movements.
The team’s research shows that the reconstructed changes in sea level during the past millennium are consistent with past global temperatures and can be described using a model relating the rate of sea-level rise to global temperature.
“The data from the past help to calibrate our model and will improve sea-level rise projections under scenarios of future temperature rise,” research team member Stefan Rahmstorf said.
In addition to Horton and Kemp, the research was conducted by Jeffrey Donnelly of the Woods Hole Oceanographic Institution, Michael Mann of Pennsylvania State University, Martin Vermeer of Finland’s Aalto University School of Engineering in Finland and Rahmstorf of Germany’s Potsdam Institute for Climate Impact Research.
Support for this research was provided by the National Science Foundation, the National Oceanic and Atmospheric Administration, United States Geological Survey, the Academy of Finland, the European Science Foundation through European Cooperation in Science and Technology and the University of Pennsylvania.
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Here’s the abstract:
Climate related sea-level variations over the past two millennia
Andrew C. Kempa,b, Benjamin P. Hortona,1, Jeffrey P. Donnellyc, Michael E. Mannd,
Martin Vermeere, and Stefan Rahmstorff
We present new sea-level reconstructions for the past 2100 y based on salt-marsh sedimentary sequences from the US Atlantic coast. The data from North Carolina reveal four phases of persistent sea-level change after correction for glacial isostatic adjustment.
Sea level was stable from at least BC 100 until AD 950. Sea level then increased for 400 y at a rate of 0.6 mm/y, followed by a further period of stable, or slightly falling, sea level that persisted until the late 19th century. Since then, sea level has risen at an average rate of 2.1 mm/y, representing the steepest century-scale increase of the past two millennia. This rate was initiated between AD 1865 and 1892. Using an extended semiempirical modeling approach, we show that these sea-level changes are consistent with global
temperature for at least the past millennium.
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Figure 1: Two points in salt Marshes in North Carolina are used as the basis for the study:
Materials and Methods
Sea level in North Carolina was reconstructed using transfer functions relating the distribution of salt-marsh foraminifera to tidal elevation (7, 12). Application of transfer functions to samples from two cores (at sites 120 km apart) of salt-marsh sediment provided estimates of PME with uncertainties of <0.1 m. For each core a probabilistic age-depth model (10) was developed from composite chronological results and allowed the age of any sample to be estimated with 95% confidence. In Massachusetts, plant macrofossils preserved in salt-marsh sediment overlying a glacial erratic, were dated using AMS 14C and pollen and pollution chronohorizons (Fig. S1). The modern distribution of common salt-marsh plants was used to estimate PME. Sea level was reconstructed by subtracting estimated PME from measured sample altitude. Corrections for GIA were estimated from local (13) and US Atlantic coast (15) databases of late Holocene sea-level index points. Detailed methods are presented in SI Text.
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They compare data at points around the world to the new SL hockey stick (in pink in the background):
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Conclusions
We have presented a unique, high-resolution sea-level reconstruction developed using salt-marsh sediments for the last 2100 y from the US Atlantic coast. Post-AD 1000, these sea-level reconstructions are compatible with reconstructions of global temperature, assuming a linear relation between temperature and the rate of sea-level rise. This consistency mutually reinforces the credibility of the temperature and sea-level reconstructions. According to our analysis, North Carolina sea level was stable
from BC 100 to AD 950. Sea level rose at a rate of 0.6 mm/y from about AD 950 to 1400 as a consequence of Medieval warmth, although there is a difference in timing when compared to other proxy sea-level records. North Carolina and other records show
sea level was stable from AD 1400 until the end of the 19th century due to cooler temperatures associated with the Little Ice Age. A second increase in the rate of sea-level rise occurred around AD 1880–1920; in North Carolina the mean rate of rise was 2.1 mm/y in response to 20th century warming. This historical rate of rise was greater than any other persistent, century-scale trend during the past 2100 y.
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The full paper is available here: PNAS_Kemp-etal_2011_Sea_level_rise
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Mike Jonas says:
June 20, 2011 at 3:38 pm
Thanks Mike! Nice summary of comments….
Should plot CO2 concentration from 1800 to 2011.5 vs sea level. You will see sea level rise started nearly 100 years before significant CO2 increase. Also during the 2000s the sea level and CO2 diverge once again. Bogus science once again by Mann’s team.
Luckily, the 2008 Mann inverted-proxy temp. reconstruction didn’t overlap the neatly grafted instrumental temp., much less diverge a little later, eh? At least he didn’t use that last 70 yr. period of man – caused sediment erosion this time to “help” the remainder turn up to fit the instrumental?
Also, apples to oranges aside, my lying eyes tell me A to B that prior to the “Summary” reconstruction, proxy + instrumental [huh?] of N. Carolina, the original reconstructed sea levels, without instrumental, increase even when reconstructed temps.are stable or decrease, so we’re in one helluva mess.
At 2 mm/yr. as of 2000 it might be hard for coast dwellers to even get much of a head start on the coming CAGW Apocalypse, so I’m recommending they just get their affairs in order and put the documents in wax sealed bottles – and hope that the end of 1860 – 2000 flattening of sea level rise has continued to date. Otherwise, they’re libel to think they’re already under water.
@- Jim Barker says:
June 20, 2011 at 4:32 pm
“I thought that some actual statisticians, some time ago, showed that by mis-application, statistics could make hockey-sticks out of any data set, even phone numbers from any phone book. Without even any need to cherry-pick.”
True, but the size of the ‘hockey stick’ blade produced by such mathematical missapplication is at least an order of magnitude smaller than the rise found in the actual data.
The earth is rising faster than the water all over the Earth, what more could we want? It should continue to rise until the next Glacial period begins.
ferd berple says:
June 20, 2011 at 4:40 pm
A great post with a sensible observation.
Below is what I posted at Bishop Hill a couple of days ago.
“The Dieppe maps are a set of maps produced in Dieppe, France in the 16th century, thought to provide clues towards the Portuguese exploration of Australia’s east coast two hundred years before Captain Cook and even earlier than the first confirmed sighting of Australia by Jansz in his 1606 expedition along the eastern coast of the Gulf of Carpentaria. The maps show part of what might be Queensland, and name the land mass “Java a Grande “”
This map shows clearly Hervey Bay and Fraser Island and the smaller islands in Hervey Bay.
On my living room wall hangs, framed, two 19th century maps of Hervey Bay used by my Great Grandfather. The serveys were done by Captain Owen Stanley, and Matthew Flinders, and these 2 maps show the smaller islands in Hervey Bay as well.
Duck, Picnic, and Little Woody Islands are today are less than a meter above the high water mark.
Further, in my 67 years of fishing and collecting bait along the foreshore, I have not seen any change. I still collect shell fish for bait from the same rocks as I did 60 years ago.
My Question is, if the seas have gone up and down as much as we are led to believe, how come these low lying islands still exist after 500 years and seemingly unchanged.
If the seas have gone up and down, it hasn’t been by much !
Science will out man the Mann – my prediction
Also, doesn’t the team say there is a ~30 year lag between when the CO2 is released into the environment and the time the warming shows up? I believe that’s the rational for why even if we stop emitting CO2 today we are going to be doomed to another 30+ years of ever increasing warming. Thus, since there is lag between CO2 release and temperature increase, should compensate the CO2 vs sea level graph by offsetting the CO2 rise by 30 years as well.
From the article’s PNAS listing:
Thus Mann’s sole contribution was data analysis, the press release (technically?) incorrectly lists him as performing research.
Well, it’s easy to see why they wanted the help of the world-renowned statistician and signal analysis expert Michael Mann, especially if they were looking for a result that was spectacularly alarming thus highly noteworthy. Mann is well known for finding rock-solid definitive signals in noisy data. He’s so good, he could find a rattlesnake in the noise from a tire leaking air.
This paper looks and feels familiar – in the same way that most new bands first ‘hits’ are always similar sounding.
I have one message for Mr Mann
CHANGE THE FLIPPIN RECORD!
It all sounds like more pseudo-science from the hockey team.
I do like the mention of a “Tump point”. According to my SOED, one meaning of the word “tump” is:
“Trivial writing, bad prose. (E20)”. How apt.
R.S.Brown says: “Dag nabbit !! I still can’t use pasted to put stuff in the comments box.”
You’re not alone. I have to constantly remind myself to use keyboard shortcuts/hot keys to paste with the new WordPress commenting.
Mark Nutley says:
June 20, 2011 at 12:14 pm
Shock horror not only is it worse than we thought it is, gasp, another hockey stick. What a pile. Will now read the paper but fully expect my initial reaction to be correct 🙂
Great all we need now is a ball and we can have a game.
Hmmm. Isn’t that interesting. I’ve just scrolled through the comments and I didn’t notice any trolls defending this paper.
Where are the unconformities in these cores? In both cores, the average rate of accumulation of peat is 1 mm per year. It is beyond belief that these 1.5 and 3 meter stacks of muddy peat remained undisturbed by wildlife for 3000 years. A single turtle scooping out a nest or a heron chasing dinner would easily displace 2 inches of peat — oops there goes 50 years of data….
Where are the hurricane storm surges? I’m not asking much: One Cat 4+ hit every 50 years on average. That means there should be over 40 of them in each core.
The C14 error bars in Fig. 1 average about 200 years. These are likely not instrumentation problems. They are probably more indicitive of the degree of bioturbation of the peat. every layer of the core is a churned mix of the top 20 cm of peat. Instead of a nice undisturbed tree core to analyze tree rings, the authors are faced with trying to make dendochron sense from a pile of sawdust turned into press board.
Core B, btw 1.45 and 1.15 m (30 cm) spans according to the C14 data about 900 years, so the RSL rate is only 1/3 of the average. They couldn’t bring themselves to change the slope of their line from 300 to 1200 AD, which would probabably point to a fall in GIA after correcting for subsidence.. They could only increase their error band. You sure don’t see and change in slope in Fig 2 RSL plot — nice and straight, constand rate of change.
Do we have another instance of “hiding in plain sight”? Core B (Turning Point) on Fig 2 RSL has a minimum date of 800 AD. But if you go back to the B chart of Fig 1, the minimum error bar goes to 600 AD. But if you honor the C14 data, you ought to carry it left to about 300 AD. Interesting that the RSL graph inset (B) sits atop where these earlier data points for Core B should plot, say 400 AD at RSL 1.4 m. The curves would not look like the agree so well any more.
Wouldn’t have worked anyway, ’cause you misspelled it!
Heh.
___________
Use FireFox with the CA script in GreaseMonkey, and you get all that stuff in a nice icon menu.
No further comment…
Well said! And a nice selection of visuals.
Very interesting, thanks!
He’s a “one trick poney” with these hockeystick graphs.
Just another brick in the wall of evidence that Michael Mann is more concerned with producing disinformation than in doing science. But what about his co-authors? This is garbage from the gitgo on so many levels than it leaves you wondering why all the whores are gathering in the food court.
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This paper is utter pap and yet another example to those with open minds of the nonsense that Team AGW is spouting. Once again they rely on the laughable Church and White tide gauge data which has never been corroborated by any other researcher. The proxies they use do not corroborate with each other but nevertheless they have somehow managed to come up with a linear trend. The two sites they have chosen do not corroborate each other but somehow they have concluded they are a model for the rest of the globe. To achieve this astounding result they had to give all the data to a person who is known not for his ability as a statistician but because of his involvement in highly contraversial analysis techniques, despite recent advice that this kind of data should in fact be analysed by proper statistiticians.
If this research was given to me by a student I would simply throw it back in his face. It is lazy and ill-conceived and appears to have been thrown together deliberately in order to support a pre-determined outcome.
It doesn’t surprise me that Penn State is involved in this fiasco again, but what does surprise me that other reputable scientists are so willing to sit back and watch this kind of dreadful hysterical tripe be publised without so much as raising their eyebrows. Meanwhile those that do stand up to attack this kind of bullshit are branded as “dangerous deniers” that put the lives of millions at risk and have their reputations trashed in the mass media.
“tallbloke says:
June 20, 2011 at 12:53 pm
According to Manns new sea level curve, the Romans built inland ports in southern England.
WUWT?”
I think Mann may have misinterpreted a telephone conversation with Jones, where reference was made to the Cinque Ports, which of course, hadn’t sank at all, but rather had been left high and dry by receding tides.
Another example of the vagaries of our common language, enhanced by the English predilection for borrowing words from our continental neighbours.
Bob Tisdale says:
June 21, 2011 at 1:49 am
Hmmm. Isn’t that interesting. I’ve just scrolled through the comments and I didn’t notice any trolls defending this paper.
Should I be pleased you no longer consider me a troll?
I took issue with the accusations of cherry picking and particularly wirth the guy who seemed to think that two photographs somehow prove that the 4 inches or so of warming claimed for the last 50 yesars an’t possibly have happened.
I have a serious question for you all: Irrespective of what you think of Mann et al, why do “regular commentators” here not call each other on obvious nonsense like that? It would strengthen your case if you did.
Chris from Hervey Bay echoes my earlier opinion. If the sea level really is rising over time, we MUST see it happen. Yet there is anecdotal evidence from many of little change over 50, 100, 150 years. I have no particular axe to grind – if it’s rising so be it. But where is the practical evidence? I would be most interested in a website where people from all over the world can post details of their own experiences, either for or against. Rather than statistical manipulation and proxy projections, we could get a first hand account of what is really happening.
The bottom line is that it matters not if the sea level is rising, the land is falling, somewhere is rebounding or whatever, the risk facing humanity has to be something solid. Where in the world do we see strong evidence of a rapidly increasing sea level? I have no idea, I am only talking of my own personal experience. But it seems others have this same experience.
On many beaches as has been pointed out, a 6 inch rise will represent feet of difference in terms of high water marks, so it must show up.
Mustn’t it?