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.
======================================================================
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.
======================================================================
They compare data at points around the world to the new SL hockey stick (in pink in the background):
======================================================================
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.
========================================================================
The full paper is available here: PNAS_Kemp-etal_2011_Sea_level_rise
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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 ……………..
Let me try this………….If the sea level was stable between approx. 1400 and the end of the 19th century, why would the Dutch increase the height of the sea-dikes? I have a picture from the North of Holland indicating sea wall enhancement since 1570 to present. somehow it does not want to upload. (Help?)
A potted summary:
The sea-level data stops 10 years ago. [comment by RHS]. The team used only tide-gauge data, ignoring satellite data. Recent data is available, is more accurate [KnR], and shows that the rate of sea-level rise has slowed and appears to have started falling. [latitude]. The team also used just one area for its sea-level, North Carolina [Al Gored], without reference to whether the land there rose or fell. [Wil]. The coastline there consists of ever-shifting sands, so is particularly unreliable for estimating sea-level. [Wade]. The N. Carolina area is actually in the far field zone of the Laurentian ice sheet, which means that it is currently falling. [Chris Hall]. Land nearby is known to be subsiding. [The Englishman].
Salt-marsh foraminifera micro fossils essentially show the rate of land erosion, not the rate of sea-level rise. [Floor Anthoni].
The graphs show sea-levels rising throughout several hundred years of cooling, yet the paper claims a consistent link between temperature and global sea-level. [stumpy].
Past sea levels are grossly understated (evidence supplied). [dtbronzich].
The acceleration in sea level rise occurred between 1865 and 1892… When it jumped from -0.1 mm/yr to 2.1 mm/yr. Meaning that the acceleration in sea level rise started long before atmospheric CO levels climbed above the low 300′s. [David Middleton]
The rate of sea-level rise is quoted as 2mm per year. That is ony 2m in 1,000 years. [Foxgoose]. (I would also note that the Colorado Uni sea-level data shows sea-level rise of more than 3mm per year in the 20th century.)
The supplemental information for the paper is full of divergences and exclusions. [Steven Mosher]. (I would also add that it is full of uncertainties.)
The paper did not have to be subjected to normal peer-review. [MarcH].
And I haven’t got to the end of the comments yet – let alone new ones coming in as I typed. Apologies to anyone whose pertinent comment I missed.
What’s scary is that stuff gets peer reviewed and published…
To quote jv
“Looks like Mann’s modeling software is good for all kinds of things. Add air you get a hockey stick shaped warming graph, add water and you get a hockey stick shaped sea level rise. I suspect he is selling the idea that if you add enough money you can get a hockey stick shaped stock market graph as well.”
Ah: so that’s where he got them from. Let’s see: here’s an experiment we can directly measure:
– start buying shares, now. Sit on them. There will be an oopsy-daisy up and down around 2017 (the end of the first, smaller “hockeystick”) with a short recession until 2020 but we stay on the roller coaster maybe buying more shares over this period. Then we sit, riding the second larger hockey stick, and sell ALL over the last quarter 2025.
2026 will be a repeat of 2008 … and the end of the hockeystick :-).
The Englishman says: June 20, 2011 at 12:45 pm
“It is a pretty good bet that land subsidence in the North Carolina coastal plain is due to heavy pumping of ground water from aquifers referred to in various places in these web pages, namely the Black Creek and Upper Cape Fear aquifers.”
Looks the same hockey stick as in Venice , Italy
“Venice was built on marshlands, a sedimentary island within a lagoon off the coast of Italy. Attila the Hun invaded Italy in 452, forcing many inhabitants to flee to the coast. A small group of islands in the center of a lagoon were collectively called Rivo Alto, or “high bank.” The area soon expanded, and Ri’Alto became the center of Venice.
Venice has always been slowly sinking. Over the last 1,000 years, it has sunk by around seven centimeters for every century, but recent reports have stated that in the last century alone, the city of Venice has lowered by around 24 centimeters. This may have more to do with global warming and the melting polar ice caps than with Venice sinking into its own foundations.”
http://www.wisegeek.com/is-venice-sinking.htm
But
Six hundred years ago, Venetians protected themselves from land-based attacks by diverting all the major rivers flowing into the lagoon and thus preventing sediment from filling the area around the city. This created an ever-deeper lagoon environment.
During the 20th century, when many artesian wells were sunk into the periphery of the lagoon to draw water for local industry, Venice began to subside. It was realised that extraction of water from the aquifer was the cause. The sinking has slowed markedly since artesian wells were banned in the 1960s.Some recent studies have suggested that the city is no longer sinking.
http://en.wikipedia.org/wiki/Venice
Also strange that there was a 0 mm sea level rise during the Roman warm period.
http://www.klimaatfraude.info/images/10000GISP2.JPG
And after all that work (harde har har) and fuss (omg) one can still walk to the beach and not notice anything going on over the course of a lifetime. Silly Millimeters/Silly Mann. Of one thing we can be certain of: The certainties are robustly uncertain. Assume.
“It seems that the more missions are added to the melting pot, the more uncertain the altimetric sea level change results become.”
Old Chinese proverb: Man with one watch knows what time it is. Man with two – not sure.
They have apparently not read Houston and Deans work that is more up to date and finds SLR decelerating.
http://www.jcronline.org/doi/pdf/10.2112/JCOASTRES-D-10-00157.1
The World Climate report web site has updated Houston’s result.
http://www.worldclimatereport.com/index.php/2011/04/07/sea-level-rise-still-slowing-down/
Thanx, Tallbloke, I’d missed that. Good question… when will Mann produce his mosquito paper? $1.8 million would translate into a couple of thousand hours of research. Maybe it’s on hold because he can’t get a hockey stick out of it.
Is there any way of finding out who actually peer reviewed this paper? (I know it’s supposed to be kept under wraps – but would anyone here like to be charged with having to ‘pass’ this work – and more importantly, would said reviewers be happy to be tarred with the same brush?)
Honestly, I think reviewers should be given as much, if not more hassle, as the author(s) when something is shown to be wrong/misleading/etc, etc – after all – aren’t they supposed to be doing a ‘proper’ job and checking the work?
How is 30 year smoothing done on the end points?
If the Greenland ice sheet is losing mass, are the coasts near greenland showing a lowering of sea level as should be expected, due to gravitational forces?
How does the temperature hockey stick, which is known to be faulty, reinforce the validity of a sea level hockey stick? Two wrongs apparently do make a right.
I have real doubts about the data obtained beneath the water in North Carolina for the obvious reasons. That land is low lying, often soft and swampy, often disturbed or rearranged by storms, and recently frequently remodeled by man. Another proxy should have been chosen. I also doubt the accuracy of the dating techniques to such fine resolution. I almost appears that he used his temperature hockey stick to calibrate seal level proxies. I also find it odd that, during the LIA, when cooling occurred, there was no corresponding drop in sea level according to his proxy. Isn’t that a bit of a problem?
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.
The British Admiralty charts have been digitized and are widely available to verify or disprove sea level change. They can be displayed on a computer using widely available charting software. These are reproductions of hand drawn charts of the oceans of the earth, drawn during the golden age of discovery before the age of industrialization.
The depths along the coast lines were drawn to an accuracy of 1 foot by men largely in wooden rowboats, using weighted sounding lines dropped over the side. The charts show who did the survey, the year, and the ship they sailed on. Many of the names are well known from history. The weighted lines used a wax plug on the end to collect samples of the bottom, and the charts tell you if it is sandy, muddy, rocky, etc. The charts also show incredible detail ashore, with mountains and streams marked, with forest and swamps and grasslands drawn in.
In many respects the work that went into these charts meets of exceeds the technological achievements of NASA in the exploration of space. These charts were by and large the charts used by all countries of the world, including the US when they created their own mapping agencies. If the charts were later resurveyed, this will be noted along with the date.
Locate one of these charts for your area. The depths are almost always drawn in reference to low low tide. This will be noted on the charts. What is noteworthy is that they don’t say “adjusted to correct for sea level change”.
Go out at low low tide. If there has been sea level rise, then the drying rocks shown on the charts should no longer be drying. they should be covered. You are looking for a symbol that looks like a cross with a dot between each of the arms of the cross. See how many of these are still there today. Each one is evidence that sea level rise, even after recovery from the LIA and 150 years of industrialization is not significant. There are tens of thousands of such rocks on the Admiralty Charts from around the world. Any meaningful survey of global sea level rise should start with these rocks, as they are by far the most accurate and extensive record on earth of pre-industrial sea levels.
But of course these surveys will not be done, as they will not prove that what is wanted. The research being done is not to establish to truth, but rather to collect evidence to “prove” sea levels are rising. Any evidence that shows the opposite will be discarded – the exact opposite of how science is supposed to be conducted.
Imagine that you were on trial for murder and the police found 2 sets of finger prints on the murder weapon. Yours and someone else. However, they discarded the second set of finger prints, and reported to the courts and the press that your finger prints were found on the murder weapon. This is climate science. Only the evidence that convicts is being reported. The evidence that something else might be responsible is discarded.
Do a global tide gauge composite, excluding all Atlantic tide gauges.
Lots of comments & havent read them all so sorry if someone has already stated the obvious below:
1) The authors explicitly state the inflection point to higher sea level rate begins between 1865-1892
2) This pre-dates any significant increase in CO2 from industrialization
3) I conclude that this is conclusive evidence that this change in rate of sea level must have a natural cause
4) The global temp record appears to tie the sea level curve fairly well at first glance – it is reasonable to assume they are related via thermal expansion of water (I am sure someone could do that calculation & see if they tie)
5) Given point 4 & point 3, it seems obvious that any change in global temps over the last 100 + years also must be driven primarily by natural causes.
Seems to me this paper pretty much kills CO2 as the dominant force in global temp changes, given the timing of on set of sea level change.
This feels a lot like Al Gore pointing out the correlation between CO2 & temps from ice core data, but failing to recognize that temps rose before CO2 – good correlation, wrong conclusion.
Obviously, plenty of posters have brought up potential technical problems. I am sure that will be a discussion that will go on for years; I will let other expand on that.
I have to say I feel a bit sorry for Mann – it really wouldn’t matter what he did research-wise from this point forward. He will be discredited out of hand by many for his past problems, regardless if this is solid work or not. That is obvious reading the comments on here. He should probably consider a career change.
Graphing the modern instrument record on to the reconstructed data where have we seen that before? Never mind I know the answer.
Whether it is faster than at any time in history or not sea level is not rising at an alarming rate, so what difference does it make.
In one of the charts, the tide gauge data for North Carolina and South Carolina are plotted as an insert – as usual buried inside thick dark lines so that one cannot really see it.
But it appears to be this chart from a Kemp 2009 paper (same lead authors – same methodology).
http://geology.gsapubs.org/content/37/11/1035/F3.large.jpg
Big bump around 1945 that was not exceeded until around 1990 – not unlike the AMO cycle which impacts the Carolinas of course.
Also note that it doesn’t really match the reconstruction – not unlike Mann’s original hockey stick.
It is just Kemp getting Mann on board with a similar hockey stick-type reconstruction.
http://geology.gsapubs.org/content/37/11/1035.abstract
So……. the temperature during the “Medieval Climate Anomoly” was within 0.3 degrees celcius of current values (plus or minus 0.2 degrees) with no explanation as to why the temp was that high a thousand years ago.
Then….. the temperature during the Little Ice Age was 1 degree celcius below current values with no explanation as to why the temp was so low then.
And…. we are instructed that both temperature and sea level began thier inexorable rise in the mid to late 1800 hundreds, prior to any possible influence from human generated CO2.
So even if I accepted the methodology and conclusions (which at this point I don’t) it would seem that we have, at best, an exposition of natural variability in climate. The study gives absolutely no joy to those who promote AGW as it really is a case of premature uptick.
A recent interview with Dr Vincent Gray ( former IPCC reveiwer turner sceptic ) also highlights studies on “non” sea level rises
http://www.financialpost.com/story.html?id=55387187-4d06-446f-9f4f-c2397d155a32
I like this quote :
Everybody knows that the Pacific island of Tuvalu is sinking. Al Gore told us that the inhabitants are invading New Zealand because of it.
“Around 1990 it became obvious that the local tide-gauge did not agree — there was no evidence of ‘sinking.’ So scientists at Flinders University, Adelaide, were asked to check whether this was true. They set up new, modern, tide-gauges in 12 Pacific islands, including Tuvalu, confident that they would show that all of them are sinking.
“Recently, the whole project was abandoned as there was no sign of a change in sea level at any of the 12 islands for the past 16 years. In 2006, Tuvalu even rose.”
I found at least one major problem already with the temperature data. Mann did not use the available HADCrutv3 data. It appears that he had a 0.5C offset in the data. Might be a splicing issue, but the offset is real from the available data.
http://theinconvenientskeptic.com/2011/06/what-instumental-record-did-mann-use/
ferd berple says: June 20, 2011 at 4:40 pm
Excellent comment! All one needs is a firm historical record and one’s eyes to disprove this fraud.
Well done.
What have we been seeing most recently? Deceleration, flattening and now falling. It’s worse than we thought. Head for Al Gore’s $8 million new beach front villa!!!!!!
http://www.jcronline.org/doi/abs/10.2112/JCOASTRES-D-10-00157.1
http://crozon.colorado.edu/
http://www.ncdc.noaa.gov/paleo/pubs/ipcc2007/fig68.jpg
http://www.ipcc.ch/ipccreports/tar/wg1/409.htm
After the hottest decade on the record, tied hottest year on the record, Greenland meltdown, glacial Armageddon, Antarctic ice sheets melting, snowfalls a thing of the past – sea level rate rise in decline.
We must act now! Me thinks someone is lying.