Further Problems with Kemp and Mann

Guest Post by Willis Eschenbach

In my previous post I discussed some of the issues with the paper “Climate related sea-level variations over the past two millennia” by Kemp et al. including Michael Mann (Kemp 2011). However, some commenters rightly said that I was not specific enough about what Kemp et al. have done wrong, so here’s what further investigation has revealed. As there is no archive of their reconstruction results, I digitized their estimate of reconstructed global sea level rise as shown in their Figure S2 (A). First, here is their Figure, showing their reconstruction of sea level.

Figure 1. Kemp Figure S2 (A) SOURCE 

I digitized the part of their graph from 1650 onwards, to compare it to recent observation. Figure 2 shows those results:

Figure 2. Kemp 2011 reconstructed global sea level change, 1650-2000 

So what’s not to like in these latest results from Kemp and Michael Mann?

The first thing that seems strange is that they are claiming that globally there has been a sea level rise of 200 mm (8 inches) in the last fifty years (1950-1999). I know of no one else making that claim. Church and White estimate the rise 1950-2000 at 84 mm (three and a quarter inches) mm, and Jevrejeva says 95 mm (three and three-quarters inches), so their reconstruction is more than double the accepted estimates …

The next problem becomes apparent when we look at the rate of sea level rise. Figure 3 shows the results from the Kemp 2011 study, along with the MSL rise estimates of Jevrejeva and Church & White from worldwide tidal gauges.

Figure 3. Kemp 2011 reconstructed rate of global sea level rise, 1650-2000, along with observations from Jevrejeva (red circles) and Church and White (purple squares).

Kemp et al. say that the global rate of sea level rise rose steadily since the year 1700, that it exceeded 3mm per year in 1950, that it has increased ever since, and in 2000 it was almost 5 mm/year.

Jevrejeva and Church & White, on the other hand, say it has never been above 3 mm/year, that it varies up and down with time, and in 2000 it was ~ 2 mm/year. In other words, their claims don’t agree with observations at all.

In addition, the Kemp 2011 results show the rate of sea level rise started increasing about 1700 … why would that be? And the rate has increased since then without let-up.

So we can start with those two large issues — the estimates of Kemp et al. for both sea level and sea level rise are very different from the estimates of established authorities in the field. We have seen this before, when Michael Mann claimed that the temperature history of the last thousand years was very different from the consensus view of the time. In neither case has there been any sign of the extraordinary evidence necessary to support their extraordinary claims.

There are further issues with the paper, including in no particular order:

1. Uncertainties. How are they calculated? They claim an overall accuracy for estimating the sea level at Tump Point of ± 40 mm (an inch and a half). They say their “transfer function” has errors of ± 100 mm (4 inches). Since the transfer function is only one part of their total transformation, how can the end product be so accurate?

2. Uncertainties. The uncertainties in their Figure S2 (A) (shaded dark and light pink in Figure 1 above) are constant over time. In other words, they say that their method is as good at predicting the sea level two thousand years ago as it is today … seems doubtful.

3. Uncertainties. In Figure 4(B) of the main paper they show the summary of their reconstruction after GIA adjustment, with the same error bands (shaded dark and light pink) as shown in Figure S2 (A) discussed above. However, separately in Figure 4(B) they show a much wider range of uncertainties due to the GIA adjustment. Surely those two errors add in quadrature, and end up with a wider overall error band.

4. Tidal range. If the tidal range has changed over time, it would enter their calculations as a spurious sea level rise or fall in their results. They acknowledge the possible problem, but they say it can’t happen, based on computer modeling. However, they would have been better advised to look at the data rather than foolishly placing their faith in models built on sand. The tidal range at Oregon Inlet Marina, a mere ten miles from their Sand Point core location, has been increasing at a rate of 3 mm per year, which is faster than the Kemp reconstructed sea level rise in Sand Point. Since we know for a fact that changes in tidal range are happening, their computerized assurance that they can’t happen rings more than a bit hollow. This is particularly true given the large changes in the local underwater geography in the area of Sand Point. Figure 4 shows some of those changes:

Figure 4. The changes in the channel between Roanoke Island and the mainland, from 1733 to 1990.

Note the shallows between the mainland and the south end of Roanoke Island in 1733, which are noted on charts up to 1860, and which have slowly disappeared since that time. You can also see that there are two inlets through the barrier islands (Roanoke Inlet and Gun Inlet) which have filled in entirely since 1733. The changes in these inlets may be responsible for the changes in the depths off south Roanoke Island, since they mean that the area between Roanoke and the mainland cannot easily drain out through the Roanoke Inlet at the north end as it did previously. Their claim that changes of this magnitude would not alter the tidal range seems extremely unlikely.

5. Disagreement with local trends in sea level rise. The nearest long-term tide station in Wilmington shows no statistically significant change in the mean sea level (MSL) trend since 1937. Kemp et al. say the rise has gone from 2 mm/year to 4.8 mm per year over that period. If so, why has this not shown up in Wilmington (or any other nearby locations)?

6. Uncertainties again, wherein I look hard at the math. They say the RMS (root mean square) error in their transfer function is 26% of the total tidal range. Unfortunately, they neglected to report the total tidal range, I’ll return to that in a minute. Since 26% is the RMS error, the 2 sigma error is about twice that, or 50% of the tidal range. Consider that for a moment. The transfer function relates the foraminiferal assemblage to sea level, but the error is half of the tidal range … so best case is that their method can’t even say with certainty if the assemblage came from above or below the mean sea level …

Since the tides are so complex and poorly documented inside the barrier islands, they use the VDatum tool from NOAA to estimate the mean tidal range at their sites. However, that tool is noted in the documentation as being inaccurate inside Pamlico Sound. The documentation says that unlike all other areas, whose tidal range is estimated from tidal gauges and stations, in Pamlico Sound the estimates are based on a “hydrodynamic model”.

They also claim that their transfer function gave “unique vertical errors” for each estimate that were “less than 100 mm”. This implies that their 2 sigma error was 100 mm. Combined with the idea that their VLSI error is 50% of the tidal range, this in turn implies that the tidal range is only 200 mm or so at the Sand Point location. This agrees with the VDatum estimate, which is almost exactly 200 mm.

However, tides in the area are extremely location dependent. Tidal ranges can vary by 100% within a few miles. This also means that the local tidal range (which is very local and extremely dependent on the local geography) is very likely to have changed over time. Unfortunately, these local variations are not captured by the VDatum tool. You can download it from here along with the datasets. If you compare various locations, you’ll see that VDatum is a very blunt instrument inside Pamlico Sound.

That same VDatum site give the Pamlico Sound two sigma errors (95% confidence interval) in converting from Mean Sea Level to Mean Higher High Water (MHHW) as 84 mm, and for Mean Lower Low Water as 69 mm.

The difficulty arises because the tidal range is so small. All of their data is converted to a “Standardized Water Level Index” (SWLI). This expresses the level as a percentage of the tidal range, from 0 to 100. Zero means that the sample elevation is at Mean Lower Low Water, 100 means it is at MHHW. The tidal range is given as 200 mm … but because it is small and the errors are large, the 95% confidence interval on that tidal range is from 90 mm to 310 mm, a variation of more than three to one.

Their standardized water level index (SWLI) is calculated as follows:

SWLI = (Sample Elevation – MLLW) / (MHHW – MLLW) x 100     (Eqn. 1)

When adding and subtracting amounts the errors add quadratically. The sample elevation error (from the transfer function) is ± 100 mm. The MLLW and MHHW two sigma errors are 69 mm and 84 mm respectively.

So … we can put some numbers to Equation 1. For ease of calculation lets suppose the sample elevation is 140 mm, MLLW is 0 mm, and MHHW is 200 mm. Mean sea level is halfway between high and low, or about 100 mm. Including the errors (shown as “±” values) the numerator of Eqn. 1 becomes (in mm)

(Sample Elevation – MLLW) = (140 ± 100 – 0 ± 69) 

Since the errors add “in quadrature” (the combined error is the square root of the sum of the squares of the individual errors), this gives us a result of 140 ± 122 mm

Similarly, the denominator of Eqn. 1 with errors adding in quadrature is

(MHHW – MLLW) = (200 ± 84 – 0 ± 69) = 200 ± 109 mm

Now, when you divide or multiply numbers that have errors, you need to first express the errors as a percentage of the underlying amount, then add them in quadrature. This gives us

(140 ± 87%) / (200 ± 55%) *100

This is equal to (.7 ± 103 %) x 100, or 70 ± 72, where both numbers are percentages of the tidal range times 100. Since the tidal range is 200 mm, this means that the total uncertainty on our sample is about 72 percent of that, or ± 144 mm. So at the end of all their transformations, the uncertainty in the sample elevation (± 144 mm) is larger than the sample elevation itself (140 mm).

All of that, of course, assumes that I have correctly interpreted their very unclear statements about the uncertainties in their work. In any case, how they get a Tump Point two sigma error of about 40 mm (an inch and a half) out of all of that is a great mystery.

Those are my problems with the study. Both the rate and the amount of their reconstructed sea level rise in the last fifty years are much greater than observations; tidal ranges in the area are varying currently and are quite likely to have varied in the past despite the authors’ assurances otherwise; and their methods for estimating errors greatly underestimate the total uncertainty.


[UPDATE] One other issue. They say regarding the C14 dating:

High-precision 14C ages (8) were obtained by preparing duplicate or triplicate samples from the same depth interval and using a pooled mean (Calib 5.0.1 software program) for calibration.

This sounded like a perfectly logical procedure … until I looked at the data. Figure 5 is a plot of the individual data, showing age versus depth, from Supplementary Tables DR3 and DR4 here. They have used the “pooled mean” of three samples at 60 cm depth, and three samples at 80 cm depth.

Figure 5. Age and depth for the Sand Point samples in the top metre of the core. Red squares show C14 dates. Horizontal black bars show the 2-sigma uncertainty (95% confidence interval).

Look at the 60 cm depth. The three samples that they tested dated from 1580, 1720, and 1776. None of their error bars overlap, so we are clearly dealing with three samples that are verifiably of different ages.

Now, before averaging them and using them to calibrate the age/depth curve … wouldn’t it make sense to stop and wonder why two samples taken from the exact same one-centimetre-thick slice of of the core are nearly two hundred years different in age.

The same is true at the 80 cm depth, where the ages range from 1609 to 1797. Again this is almost a two hundred year difference.

What am I missing here? How does this make sense, to average those disparate dates without first figuring out what is going on?


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John A

Yep, the Curse of Mann strikes again.
Willis you should write this up as a comment and send it to the journal

John Marshall

Sea level rise is a strong reason to give some people money claiming that they can do something about saving coastal communities.
A few months ago the BBC news did a report on east of England floods which, in 1953, inundated low lying coastal areas of Lincolnshire and South Yorkshire due to a storm surge during a spring high tide. Over 300 people died that night.
In the report the BBC stated that due to Environment Agency data sea levels had risen 1.5m since that date intimating that flooding was imminent. I complained to the BBC for reporting such rubbish stating that sea levels had in fact risen by 174mm maximum, 3mm per year for 58 years, assuming that the 3mm rate was unchanging. I also complained at the possible panic and fear instilled into the people of the local area.
I had no reply from the BBC.
The Environment Agency, our EPA and just as stupidly bound to all this false science, insisted that their sea level rise data was accurate.


You are a weapon of mass destruction. ;O)


“Never screw up a good story by checking the facts”. I think you might have mistaken Mann for a scientist, he is not a scientist he is a activist/journalist/story teller.
+1 for the John A suggestion.

….which basically says the peers who reviewed this paper have jacksquat qualification to do so, or are thouroughly besotted by the star power of hockey sticks. Or both.

Berényi Péter

I have already posted it at Cooks’s site, but got no meaningful response (other than to post it at RealClimate, which I would never do because of their unreasonable and politically loaded moderation practice).
We can check it [Kemp’s claim] with the Interactive Sea Level Time Series Wizard of the CU Sea Level Research Group.
Sand Point (A): 35.87N 75.64W – sea level rise (1993-2011): 0.496 mm/year
Tump Point (B): 34.99N 76.36W – sea level rise (1993-2011): 1.049 mm/year
These are satellite data, so sea level rise at the Atlantic coast of North Carolina is specified relative to the true geoid here. You can see current local rate (for the last two decades) is small.
On the other hand if you check nearby tide gauges in the region, some show quite substantial rates of sea level rise for the same period, like the one at Hampton Roads (5.6 mm/year, close to Norfolk, Virginia). These rates are not measured relative to the geoid, but to local coastal elevation, therefore the difference is due to land subsidence.
This rate is much higher than the (GIA related) secular rate specified by Kemp 2011 (0.9-1 mm/year). Recent acceleration of subsidence on the coastal plain is most likely due to groundwater depletion (sediment compactification occurs as pressure in coastal groundwater table is decreased by overexploitation). There is also a high local variability in this rate, because it depends on both nearby drilling history and structure of local layers at depth. Unfortunately Kemp at al. do not even try to address this effect.
You can check the background in this USGS report:
USGS – science for a changing world
Professional Paper 1773, First posted November 8, 2010
Groundwater Resources Program
Groundwater Availability in the Atlantic Coastal Plain of North and South Carolina
Edited by Bruce G. Campbell and Alissa L. Coes
This interpretation is consistent with the fact the bulk of local sea level rise acceleration (relative to coastal elevation) happened in the late 19th century, when industrial scale drilling for groundwater became feasible.
It means Kemp at al. possibly detected a local signal unrelated to global sea level change, but caused by recent local anthropogenic effects on coastal elevation.

From the USGS report:
“As of 2004, large volumes of groundwater being pumped in the CCPCUA ([North Carolina] Central Coastal Plain Capacity Use Area) had affected groundwater levels and flow regimes (State of North Carolina, 2004) in the aquifers and confining units underlying the area. As the simulated groundwater flow budget analysis indicates, groundwater continues to be removed from storage in many of the hydrogeologic units, and groundwater level declines continue to occur. Until these reductions in groundwater storage are lowered or stopped, groundwater availability will continue to decline in this area.”
For example PSMSL station DUCK PIER OUTSIDE is not too far (less than 30 km) from Sand Point (where secular coastal land subsidence rate is said to be 1 mm/year). If you calculate rate of sea level change relative to the tide gauge station there between the end of 1992 and beginning of 2010, it turns out to be 4.86 mm/year. On the other hand satellite data at the same location and for the same time period show 1.16 mm/year.
It means land subsidence rate at Duck Pier is 3.7 mm/year during the last two decades, almost four times the secular rate due to GIA alone. The additional 2.7 mm/year is probably caused by decreasing pressure in the groundwater table adjacent to the coast. And this (clearly anthropogenic, but local) phenomenon is a new one, caused by excessive drilling and pumping in the region (which, unlike fast increase in global atmospheric CO2, started in the late 19th century indeed).


I never thought I would ever see this on a single page.
Prof. Nils-Axel Mörner, Michael Mann, The Maldives, sea level rise and a greenhouse. ;O)
A lot of warmists are having a problems with the rate of sea level rise which appears to have decelerated over the past 80 years. The rate of sea level rise is showing itself to be very un-cooperative despite the ‘necessary adjustments’ and an ‘acceleration’ global ice meltdown.

And, a recurring question – how have the numerous hurricanes altered the coastline, particularly the barrier islands?
How many cuts were opened, or how many passages filled in? These would also alter the water flow and tidal variations.
As an example, one can look at barrier islands in other places – one is Ship Island off the Miss Coast.
In 1969, Hurricane Camille with its 30-foot (9.1 m) tidal surge cut the island into 2 separate islands, to form East Ship Island and West Ship Island. The gap is known as the Camille Cut.
In 1998, Hurricane Georges washed away a mile of East Ship Island’s beach.
In August 2005, Hurricane Katrina almost completely submerged East Ship Island. West Ship Island received most of the damage as Katrina’s 30-foot (9.1 m) tidal surge wiped out the visitor and employee facilities on the island as well as the island’s pier and board-walk.
In 2008, Ship Island was surveyed just 2 weeks after Hurricane Ike. Scientists had a difficult time finding the island. The eastern half of the island had completely disappeared, leaving only parts of the western half. It is unknown whether the island was eroded by Hurricane Ike, or more likely Hurricane Gustav that hit just 2 weeks earlier.
So if one island has had that kind of damage, how did the barrier islands of N Carolina fare?
Here’s a map of the hurricanes that have affected the N Carolina coast since 1970:

Craig Loehle

Move along, these are not the error bars you are looking for…


Coming from an Analytical Chemist with a strong background in statistics, this is no different than any of the other crap pushed by this group. The measurement system is simply no where near robust enough to support the claims they want to make. Furthermore, it’s not really the measurement system’s fault, it’s the fault of the noise in the system that the “scientists” are trying to measure and the “scientists” overextending the measurement system. Complicit blame should also go to any/all reviewers of the work in peer-reviewed journals.
If climate were a hard science like the physical sciences (chemistry and physics, specifically), their standards would be forced to be much higher. We had a really good group doing environmental analytical research and their data always looked like shotgun patterns with r squared values somewhere around 0.55 where everyone else in the department that dealt w/more controlled systems had r squareds always north of 0.99 unless they were brave.

Beth Cooper

Build on the rock,
And not upon the sand.


Some people here may have missed what appears to be physically impossible claims of the paper.

Ralph Stea

If the glacio-isostatic adjustment comes from Peltiers earth model then it is flawed. The Peltier model fails to predict post-glacial sea-level change in the periphery of the Laurentide Ice sheet (New England) no matter what ice configuration is used.

Rob Dawg

They have inadvertently discovered Anthropogenic Ground Level Subsidence.


My first reaction reading Mann’s sea level paper was why in the world would anyone be tracking sea level rise on barrier islands? These are not stable geologic entities as they are built up and destroyed by sand and silt movement. I know the areas Dr Mann looked at were on the bay side of the island but I would think sand dune height, water table rise and fall could easily lead to the rise and fall of the entire island by both natural and civil/developmental effects. In other words I am asking the basic question, is Dr. Mann’s paleo tide Gage the equivalent to potting a tidal yard stick on a floating dock?


An excellent review as always – thank you Willis. Why did the formal peer review process not pick up these points?
As a UK resident I’m afraid that is all I’m prepared to say here in view of the Mann v Ball defamation suit. However even in the UK we can still think what we like of the integrity of Dr Mann’s statistical offerings – and of course US citizens have freedom of speech to comment as they wish.


Re: John A

Willis you should write this up as a comment and send it to the journal

A good idea except that Willis has had to guess many of the parameters due to the poor quality of the paper. This means that any miss-interpretation by Willis will be pounced upon by the team and used to justify disregarding it in its entirety. The journal will also give Kemp and Mann the last word and you can be sure that would simply ignore Willis’es results due to unavoidable errors and perform their own calculations, that have nothing to do with Willis’es points, but proves, beyond doubt, that some entirely unrelated point in the paper is correct.
If Willis were to write a comment he would have to have the full co-operation of Kemp and Mann and be provided with all the details he is having to guess at. That will happen in the middle of the next ice age when Hell freezes over.

Willis Eschenbach

I’ve put an addendum at the end of the article that discusses a conundrum with the radiocarbon dating.

Dave Springer

It appears that after conducting some good science in local paleo sea level reconstruction using well established methods the authors go on a witch hunt where the witch’s name is anthropogenic carbon dioxide. Their paper falls to pieces at that point. Local relative sea level change can be extreme and have jack shit to do with steric sea level change and everything to do with land rising or falling relative to the ocean. That’s not to say humans aren’t contributing to isostatic sea level change. Look at New Orleans fercrisakes. No one denies that human activities are causing that region to sink like a stone orders of magnitude faster than steric sea level rise. Land use changes that change the characters of the soil and water table near coastlines have dramatic effects such as what’s happening to New Orleans and the land use changes need not be near the coast at all but can happen far inland by changing the flow rate and sedimentation loads of rivers which eventually drain into the ocean. One or two millimeters per year in subsidence is SO easily caused by land use changes it’s simply not possible to separate it out from other factors in a paleo reconstruction using just a couple of salt marsh cores within geologic spitting distance of each other and both in heavily used industrial and agricultural regions. Repeating this study in a few places where land use change can be ruled out as a factor needs to be done before even a tentative conclusion can be reached.

Papa Bear 38

There are several references to GIA (Glacial Isostatic Adjustment) in your critique. Unfortunately, a poorly directed search on Gore’s interwebz thingy will be dominated by the utterly irrelevant Gia Carangi – proof that we are indeed doomed (it is MUCH worse than we thought). It would be very good to put in a reference such as http://sealevel.colorado.edu/content/what-glacial-isostatic-adjustment-gia-and-why-do-you-correct-it in the article.

They publish in PNAS and the member of the academy sponsoring the article gets to cherry pick the reviewers for the article. Namely, no substantial peer review at all in some cases.


I do not understand why Mann has not been laughed out of science. In both cases, temperature and sea level, his work is horrible and goes against the accepted (at the time) scientific consensus. This paper would make a laughing stock out of an undergrad, but he gets it published in a respected journal.
Someone tell me why this is so.

henrythethird says:
June 26, 2011 at 4:52 am
And, a recurring question – how have the numerous hurricanes altered the coastline, particularly the barrier islands?

Sean says:
June 26, 2011 at 6:09 am
My first reaction reading Mann’s sea level paper was why in the world would anyone be tracking sea level rise on barrier islands?

The only other state that has had more hurricane strikes than North Carolina is Florida. If you look at a map, you will see why. North Carolina sticks out and catches many hurricanes. North Carolina also catches some Nor’easters, extratropical lows, that can do as much damage and sometimes more damage than a hurricane. The barrier islands of North Carolina are known as the Outer Banks, and the area inside the barrier islands are known as the Inner Banks. The Outer Banks are formed by the Gulf Stream current. In fact, the ocean water is much warmer at the southern part of North Carolina than the northern part. Because of the constantly shifting sand, people have called the Outer Banks the graveyard of the Atlantic. Blackbeard the pirate knew where the shallow sands were, which is why he made his hideout inside the Outer Banks. In the northern part of the Outer Banks is a town called Nags Head. The locals used to tie a lantern around a donkey, which they called a nag, and had it walk on the beach. Ships at night would see the lantern and would assume it was a lighthouse. Because the light was small, ship captains thought the lighthouse was far away, so they sailed toward the light, only to wreck on the sand and be plundered. I personally have seen the shifting sands in my lifetime. I remember when Cape Hatteras lighthouse was at its original position, before it was moved, and I remember seeing the sands give way over the years. My family used to go to Cape Lookout lighthouse, when it was still owned by the Coast Guard, and camp at the base of the lighthouse. Cape Lookout is inside a barrier island, so it is not directly on the ocean. I remember seeing a marker in the water that today is now on land. And my last Outer Banks story is about Jockey’s Ridge state park. This state park is in Nags Head and is a series of sand dunes. The dunes are always changing, old sand is blown into the Albermare sound, new sand is blown in from the ocean.
There is a point to my stories. I believe Michael Mann chose North Carolina for a reason. And not because of the history and the lighthouse tours. A place with as much shifting sand and as many hurricanes as North Carolina is an excellent place to say sea level is rising. Did Michael Mann account for erosion due to hurricanes and Nor’easters? Doubtful. The sands shift so much that there will be noticeable changes in 5 years. I believe Michael Mann chose North Carolina because it provided the results he was looking for. Much like choosing the trees that fit your agenda and discarding those that do not. Put data in a database, don’t ask why the values are what they are, and claim a hockey stick. There is no part of the North Carolina coast that is not affected by the shifting sands. I have another story about that. Wilmington, NC was a major port in the American Civil War. To get to the Wilmington port, ships had to enter the mouth of the Cape Fear river and pass by a place called Fort Fisher. The confederate army made a sand fort at Fort Fisher to survive Union army bombardments. When the confederate army made the sand fort, it was adjacent to the Cape Fear river. Today it is several hundred feet from the river. Every tidal gauge in North Carolina should not be trusted.


And this is supposed to be a peer-reviewed paper? Doesn’t say much for the reviewer given what seem to me to be fairly basic flaws. You would have thought that they would have learnt from the hockey stick fiasco that anything they publish will be subject to independent scrutiny. Maybe since they ‘know they are right’ they don’t care?

George Tetley

Having flown around the world ( from London to Auckland 47 times ) I have some idea as to how much water is contained in our oceans, IF, I repeat, IF our planet was affected by a gravitational pull of say 2 milligrams to the left, the oceans, climate , weather, earths magnetic core would all respond in different ways. Now if this has already been through the Met offices new super, super, super computer I have yet to read the results. But I think that those that composed this theory ( and it is only a theory ) are walking on water ( which I,with all reading this would pay good money to watch )


Kemp says sea levels have been rising since 1700. This clearly cannot be caused by human CO2 production as there was no significant CO2 production in 1700.
This would argue that since sea levels have been rising since 1700, temperatures must have started rising around 1700. And since we know from the ice cores that CO2 follows warming, we can conclude the increase in CO2 that started in 1850 most likely is a result of the warming that started in 1700.
The Kemp study shows two things:
1. Sea level rise started BEFORE industrialization started.
2. CO2 rise stated AFTER warming started.
Therefore, because cause cannot follow effect, sea level rise and warming cannot be the result of CO2, they must be indicators/drivers of CO2.


Sean says:
June 26, 2011 at 6:09 am
My first reaction reading Mann’s sea level paper was why in the world would anyone be tracking sea level rise on barrier islands? These are not stable geologic entities as they are built up and destroyed by sand and silt movement. I know the areas Dr Mann looked at were on the bay side of the island but I would think sand dune height, water table rise and fall could easily lead to the rise and fall of the entire island by both natural and civil/developmental effects. In other words I am asking the basic question, is Dr. Mann’s paleo tide Gage the equivalent to potting a tidal yard stick on a floating dock?
Answer to why. Easy a paid vacation at the beach! Probably tax payers money to boot.


Sean says:
June 26, 2011 at 6:09 am
My first reaction reading Mann’s sea level paper was why in the world would anyone be tracking sea level rise on barrier islands? These are not stable geologic entities as they are built up and destroyed by sand and silt movement.
Perhaps the houses built on these sands are extremely valuable and the owners are extremely rich and influential? Perhaps these same land owners are hoping to show that their properties are at risk due to human causes, not natural causes, and thus get the government to pay to protect them? Perhaps the universities in question are hoping that these same wealthy landowners will then reward them with hansom endowments in return? Perhaps the researchers in question are hoping that these endowments will pay for even more rewarding research?
Or perhaps the study had to be done in an area of shifting sands because there is no place on earth with a stable, rocky coastline that would minimize/eliminate the effects of land use and weather on tidal records.
No place like this for example:


Well done sir. You need a youtube video to go with your essay.

mike g

Does this Mann fellow ever do anything that looks like science instead of this kind of claptrap? How could this kind of crap survive peer review except that the peer-review process is completely broken, at least for climate science, if not for all science.

Ex-Wx Forecaster

This study appears to be so badly done, I can only hope it finally puts an end to the Reign of Mann the Duplicitous.
I’m not qualified to address the quantitative processes used to make the Sea Level Hockey Stick, but I have a few qualitative questions about the location of this study:
1) The geomorphology of North Carolina is that of a submergent coast. Was this addressed in the Kemp, et al study? It would help if they released their data.
2) Post-glacial, isostatic rebound seems to be treated by many as though entire continents evenly rebound from the most recent Pleistocene glaciation. In fact, they don’t. On North America, there is a large area, centered on the Canadian Shield, which continues to uplift as it rebounds. But, the uplifting area is at least partially surrounded by a band of subsiding land, which was buoyed upward by the weight of the nearby, icebound continental mass pressing downward into the mantle, and is also part of isostatic rebound. Last time I looked, North Carolina lay within the band of subsidence. Does it? If it does, at what rate is the Carolina coast subsiding during rebound? These questions would have to be addressed before any claim of sea level rise based on information from the study area could be validated.
3) Land subsidence due to groundwater withdrawal is a problem in the North Carolina coastal plain. Did the authors address whether or not their study area is completely outside the coastal plain subsidence area? This is especially important since subsidence effects from groundwater withdrawal have been increasing in the latter half of the 20th Century.
4) The site lies near a river mouth and is underlain by deep sediment deposits, much of which is Holocene in age. How deep are the sediments? Unconsolidated sediment will consolidate under its own weight–are the sediments beneath the study area measurably consolidating? If so, how quickly?
These are just the first things that popped into my head when looking at the location that Kemp, Mann, and others used as a proxy for worldwide sea level changes. Since any of the four would give the impression of sea level rise, it is particularly important, if true sea level changes are sought, to adequately address these issues. If instead, one only wishes to “prove” to a perceived gullible public that sea level is rising at an accelerated rate, then, by all means, chose one spot on a submergent, deep-sediment shoreline where natural consolidation is being augmented by active groundwater mining, and where isostatic rebound subsidence my be contributing to your cause.

mike g

huishi says:
June 26, 2011 at 7:04 am
… This paper would make a laughing stock out of an undergrad, but he gets it published in a respected journal.
I don’t think it is appropriate to call the subject journal a “respected jorunal” any longer.


Figure one shows the results of using an erroneous temperature reconstruction, put into an erroneous sea level model, disagreeing with an erroneous sea level reconstruction.
The temp reconstruction is wrong because it’s validation statistics are crucially dependent on misuse of the Tiljander proxy. The sea level model is wrong for reasons discussed extensively at:
The sea level reconstruction is wrong for reasons discussed here:

If you want to read a good short piece on why Mann’s work is without a doubt a work of poor assumptions writ large, ie assumptions that disagree with known science, read the limk. (If it works).
http://www.csam.montclair.edu/earth/eesweb/valenti/EATECh10Coasts.ppt#256,1,Slide 1


Fig 5. Bioturbation could explain the results. Worms and such drilling up and down mix the sample irregularly. Accuracy in 14C dating depends on isolation of the sample from external sources of carbon.


Sean says:
June 26, 2011 at 6:09 am
My first reaction reading Mann’s sea level paper was why in the world would anyone be tracking sea level rise on barrier islands?
Because North Carolina has gone from a fly-over state, to a must win……
….Obama only won it by around 15,000 votes
If Ohio had a coast, we could expect the same doom papers….
No one can say how political climate science is……and ignore the obvious


Looking at Fig. 2 it looks like the Holy Law Dome CO2 Ice Core Data. All blind faithers in CO2 as the main driver of temp change in the last 1 or 2k years manage to make their graphs look like a plotting from Law Dome Data. Because it has to look like a Law Dome graph or the faith is undermined. Maybe the Law Dome data was smeared into this paper’s data directly (unlikely) or through use of borrowed data, controls, etc. (not unlikely).


Willis –
I ALWAYS learn something from you (eg., errors in quadrature). I don’t know how you do it – your dissection is impressive as hell. Many many thanks for what you do.

richard verney

Beth Cooper says:
June 26, 2011 at 5:14 am
Build on the rock,
And not upon the sand.
Not entirely sure what Beth meant by this, but I envisage that I agree with her.
It is a prerequisite of any meaningful study into sea level rise that one uses a stable coast line as the point of reference. Given what I nderstand to be the geography of the location selected, it is obvious that the location selected is unlikely to have a stable coast line. That being the case, it was plain dumb to select this area as the point of study and any results would necessarily be of local relavence only, and wider extrapolation dangerous. The study appears to be built upon (shifting) sand.

Sea level is influenced by water held in storage and only Chao et al. (Science 320:212-234) have bothered to make the correction. They found that the corrected sea level curve became linear for at least the last eighty years and had a slope of 2.46 millimeters per year.

Jeff Mitchell

It is real clear Mann is not a scientist, but rather an activist exploiting a fad. His defensiveness with his data and methods clearly show he knows stuff is wrong with his process and conclusions. If he was really interested in the truth, how the ocean levels really work, he’d pass out drafts of his paper to others to check his work before he published garbage and be made a fool. There are several people that post here that would have been happy to do that for him, for free. But no, he had to publish it without that feedback that he is now getting that would have earlier prevented this embarrassment. The result is that the peer review process now has additional evidence that it doesn’t stop scammers, the reputation of a journal has been lowered, and he is still apparently an idiot for not taking simple precautions and checking his work out before publication.
No science, just investing in his false religion.


You can also see that there are two inlets through the barrier islands (Roanoke Inlet and Gun Inlet) which have filled in entirely since 1733. The changes in these inlets may be responsible for the changes in the depths off south Roanoke Island, since they mean that the area between Roanoke and the mainland cannot easily drain out through the Roanoke Inlet at the north end as it did previously. Their claim that changes of this magnitude would not alter the tidal range seems extremely unlikely.”

It would seem to be a certainty that the tides would be severely attenuated by the lack of these inlets, since any incoming tide would have to follow a much longer path to arrive at Roanoke Island.
Sometimes it seems everything Mann touches is based on delusional. Apparently he wants to write his name bold across the scientific heavens, so he goes where no rational man has gone before. n doing so, he continually goes against “consensus,” then argues that HIS position is the consensus. Result? Anyone who defends the previous consensus (remember the MWP in the early IPCC report?) becomes the deniers.


Tropical Pacific Sea Level DROPPED From 1958 – 2007, New Study Shows


I forgot:
H/t Notrickszone

LOL! This paper was NOT peer reviewed in any traditional sense. It was edited by a pre-arranged editor!
See editor comment and the star behind it below the author listing, the fine print says it had a “pre-arranged” reviewer.


In my part of the world, Canada, large parts of two provinces (Quebec and Ontario and felt as far away as Toronto and Windsor, Montreal, Boston, Chicago, Syracuse, N.Y., and Cleveland.) experienced a 5.0 earthquake. This earthquake was caused by a geological phenomenon called “isostatic rebound,” said University of Toronto geologist Russell Pysklywec.
Most of North America was buried under two kilometres of ice 10,000 years ago, he explained. Since then the Earth has been slowly rebounding back to its pre-ice age levels. Now considering Willis’s paper, granted many figures were best guess scenarios, and as so many others have commented on here from hurricanes, islands forming and being wiped out, new inlets opening and closing in that particular region – it is doubtful Mann’s paper would pass any reputable university level laugh test.
Moreover, due to the above isostatic rebound earthquake in Quebec/Ontario it appears we are scientifically unable to tell what the pre-ice age level of North America’s land mass was or wasn’t at this point in time not to mention pre-ice age sea level. Furthermore more evidence points to the massive earthquake off the Japanese Northern coast moving Japan approximately 12 feet closer to North America while dropping the Japanese coast experts say that the huge shake, caused by a shift in the tectonic plates deep underwater, also threw the earth off its axis point by at least 8 centimeters. The March 11 earthquake that hit eastern Japan was so powerful it pulled the entire country out and down into the sea. The mostly devastated coastal communities now face regular flooding, because of their lower elevation and damage to seawalls from the massive tsunamis triggered by the quake. More evidence of quake effects and coast line movement throughout history are all available for anyone who has some understanding of the historical world.
With plate tectonics in play rising some coastal areas and dropping others throughout the world, not to mention weather forced changes in reference to land mass and coastal regions – Mann’s paper and all others to this point in time seem to exclude every other natural event at work on the planet as if land were an immovable object excluded from every other natural phenomena. Therefore, no paper on sea level is worth the paper its written on to this point in time in my opinion. I am also of the opinion whether seas are relatively warm or cold also has a very well known effect on water levels – which I do not see mentioned in any paper to date and what exactly are the warm/cold rise/fall.

Septic Matthew

Willis, I have a small comment on style. You wrote: the estimates of Kemp et al. for both sea level and sea level rise are very different from the estimates of established authorities in the field.
You don’t really recognize “authorities” in their field. The fact that new estimates contradict old estimates should lead one to examine the old estimates as well. That said, the Kemp et al estimates are not very, ahem, “firm”, having been written in sand. Kemp and co-workers have a long research project in this geographic spot, they are milking the data for all they can get, in the usual academic way. There will be more in the future and their method may be adopted for other regions. Maybe in the end all of the collaborative efforts will produce something more sound. Think of all the work that followed the first flawed MBH papers.
Meanwhile, I did mean that only as a comment on one weak sentence. Your two posts show good work. I appreciate it.
As before, may I recommend that you write your work up as a technical comment for the journal that published Kemp et al? I’d be interested in reading what you have to write about the responses of the editors.
John F. Pitman wrote: If you want to read a good short piece on why Mann’s work is without a doubt a work of poor assumptions writ large, ie assumptions that disagree with known science, read the limk. (If it works).
For a long thorough discussion of statistical and data issues in Mann’s work, read The Annals of Applied Statistics, vol5, March 2011, pp 5 – 123. Data, code and other supporting material can be had from the Institute of Mathematical Statistics: http://www.imstat.org.

Septic Matthew

Peter Berenyi wrote: It means Kemp at al. possibly detected a local signal unrelated to global sea level change, but caused by recent local anthropogenic effects on coastal elevation.
Has anybody asked Kemp directly what he (or co-authors) thinks about the disparity between their rate estimates and those from the satellite data?

Jan v J

@richard verney
q.v. Luke VI 48&49