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.
w.
[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?
Yep, the Curse of Mann strikes again.
Willis you should write this up as a comment and send it to the journal
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.
Willis,
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.
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:
http://www.edf.org/article.cfm?contentid=5376
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.
HF
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.
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.
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
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.
I’ve put an addendum at the end of the article that discusses a conundrum with the radiocarbon dating.
w.
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.
Willis,
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.
The area is ideal for coastal proxy research. /sarc
403 hurricanes hitting North Carolina
Largest Earthquake in North Carolina – 1916 [Magnitude 5.20]
Land subsidence on the coastal plain
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.
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?
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:
http://www.john-daly.com/
@wade
Well done sir. You need a youtube video to go with your essay.
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.
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.
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:
http://climatesanity.wordpress.com/critique-of-a-semi-empirical-approach-to-projecting-future-sea-level-rise-by-rahmstorf/
and
http://climatesanity.wordpress.com/critique-of-global-sea-level-linked-to-global-temperature-by-vermeer-and-rahmstor/
The sea level reconstruction is wrong for reasons discussed here:
http://www.worldclimatereport.com/index.php/2011/06/24/local-vs-global-sea-level-rise/
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.
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.
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.
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.
THIS IS NOT REAL SCIENCE!
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.
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.
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?
@richard verney
q.v. Luke VI 48&49
Does anyone know what Kemp’s scientific reputation was before Mann? Cause I’ll discount anything I read from him after.
@richard verney
Although
Matthew VII 24-26
may be better (more literal).
Frauenfeld, O.W., Knappenberger, P.C. and Michaels, P.J. 2011. A reconstruction of annual Greenland ice melt extent, 1784-2009. Journal of Geophysical Research 116: 10.1029/2010JD014918.
Background
The authors write that the “total annual observed melt extent across the Greenland ice sheet has been shown to be strongly related to summer temperature measurements from stations located along Greenland’s coast, as well as to variations in atmospheric circulation across the North Atlantic,” and they indicate that the total extent of Greenland ice melt “has been increasing during the last three decades,” with the melt extent observed in 2007 being “the greatest on record according to several satellite-derived records.” Therefore, one could well ask, if these several observations might not constitute a manifestation of what climate alarmists typically describe as one of the major consequences of the supposedly unprecedented rate and degree of recent global warming?
What was done
In an exercise designed to broach this question, Frauenfeld et al. created, as they describe it, “a record of total annual ice melt extent across Greenland extending back approximately 226 years by combining satellite-derived observations with melt extent values reconstructed with historical observations of summer temperatures and winter circulation patterns.”
What was learned
The three U.S. researchers report discovering that “the recent period of high-melt extent is similar in magnitude but, thus far, shorter in duration than a period of high melt lasting from the early 1920s through the early 1960s,” and they say that the greatest melt extent over the last two and a quarter centuries did indeed occur in 2007. However, as they go on to say, “this value is not statistically significantly different from the reconstructed melt extent during 20 other melt seasons, primarily during 1923-1961.”
What it means
Frauenfeld et al. conclude that “there is no indication that the increased contribution from the Greenland melt in the early to mid 20th century … resulted in a rate of total global sea level rise that exceeded ~3 mm/yr.” And they note that this observation suggests that “Greenland’s contribution to global sea level rise, even during multi-decadal conditions as warm as the past several years, is relatively modest,” which is a far, far cry from the catastrophic result climate alarmists claim should occur in the face of their unprecedented global warming claim.
It’s not that they don’t care, it’s that the know any rebuttal will most likely not get past the gatekeepers. If it does, it will be so butchered as to be a non-rebuttal.
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.
This is the surreal world of CAGW in a nutshell…
Take a set of disparate values and calculate an average…
These can be any old numbers provided they have been selected by THE TEAM
Then calculate an anomaly to obscure the underlying values…
Then claim the result represents the GLOBAL situation…
Works with temperatures and sea level every time…
This technique has a name:
Calculate Random Average Post-normal
O.K. Time for the easy version again.
Is sea level going up, down, or sideways?
Inquiring minds want to know.
The reading of a tide gauge is a result of many changes. No. 2415 in the link below is the sea level trend of Osaka over more than 100 years, and shows a 2.6-METER SEA LEVEL RISE. Actually this reflects the land subsidence due to building construction and aquifer depletion, which are conspicuous in the developing times (1920-40s and 1950-70s). Other places (sorry in Japanese) show similar subsidence effects, but a few places exhibit general sea level fall, of which no one is sure about the true causes.
http://cais.gsi.go.jp/cmdc/center/graph/kaiiki5.html
The place-to-place variability is evident also in the places below:
http://cais.gsi.go.jp/cmdc/center/graph/kaiiki3.html
Based on these observations I feel tide gauge records tell nothing about the global sea level trend.
Thank you Berényi Péter for the reference to USGS PP 1773. I enjoyed reviewing the text and graphics of the report while enjoying a Sunday afternoon beer! I was able to learn a little about some hydrogeology on the other side of the continent, and as a bonus, I spotted a few hockey sticks!
The exceedingly well documented paper provides groundwater data from hundreds of wells on the Atlantic Coastal Plain between Virginia and Georgia (including the barrier islands of North Carolina). Also included is a discussion of the hydrogeology of the region provided as background for the ultimate purpose of the paper (groundwater modeling intended to address future water supply issues related to the development of groundwater resources).
Cursory review of the hydrogeologic data combined with application of fundamental engineeering principals suggests that if the tidal gauges utilized in the Kemp report were going to be subject to ground water extraction related ground settlement then it would be most likely due to water extraction from the youngest, shallowest and most consolidation-prone Pleistocene sediments. The maps provided in the report indicate that the extent of the shallowest confined aquifer (Yorktown Aquifer) includes the entire area of the North Carolina barrier islands. And intersetingly enough, when you get to the end of the report, the modeled well hydrographs for the Yorktown Aquifer take the shape of inverted hockey sticks! Water levels remain nearly unchanged from 1900 to about 1940 and then begin to decrease exponentially (coincident with the timing of known development of the aquifer) to about 1990 and then bounce around at the new lowered level up to the present time.
Consolidation of the dewatered aquifer materials would be expected to be relatively rapid after the time of drawdown. However, consolidation of the fine grained (clayey) sediments in the overlying aquiclude would be expected continue for a long period of time after the pore pressures were reduced by dewatering due to their relatively impermeable nature (i.e. it takes a long time for the water to get out of the low permeability materials). My guess is that this condition has resulted in some engineering issues for public works and private developments on the islands and is probably well documented in local agency records and consultant reports. Someone familiar with the local area could probably shed some light.
I’d research it on the internet if I had more time today. However, my beer is done!
RoHa says:
June 26, 2011 at 5:24 pm
Indeed it is.
w.
Jeff Alberts says:
June 26, 2011 at 2:37 pm
“It’s not that they don’t care, it’s that the know any rebuttal will most likely not get past the gatekeepers. If it does, it will be so butchered as to be a non-rebuttal.”
===
Oh Noes, they do care, yet fear if the truth be spoken, the words will be twisted to foster the agenda.
How’s that?
Thanks, Willis. It’s all clear to me now.
John A says: June 26, 2011 at 3:30 am
“Willis you should write this up as a comment and send it to the journal”
HOW ABSURD!
Willis, you should be Paid to write this up and send it to the journal.
It is hard to imaging we’re talking about these trivial variations like they were some kind of serious problem. This is a non-trival climate induced variation: http://en.wikipedia.org/wiki/Lake_Agassiz and it was not a problem. Unemployed people without shoes or a roof over their heads or SUV’s in the drive did quite well all around the world while this kind of thing was happening. It is called adapting. It is part of the cycle of life on Earth. When did half a degree and 6″ of sea level rise become a crisis?
Berényi Péter says:
June 26, 2011 at 4:26 am
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.”
Bingo! It took me less than an hour to figure out what was behind their data and I wrote it up a week ago on the first Mann/Kemp thread. The big clue was a great acceleration in rate of sea level rise circa 1880. This is entirely inconsistent with anthropogenic CO2 driving steric sea level rise. That factor is a consistent linear rise that began in the late 18th century not the late 19th. Isostatic subsidence caused by unloading of northern glaciers is also not consistent with a spike in rate of sea level rise like that as that will also be more or less linear over thousands of years. Thus I wondered what else was happening around 1880 to explain the spike. A bit of digging revealed that between 1850 and 1900 North Carolina’s gigantic tobacco industry was established engendering huge land and water use changes which would almost certainly effect the coastal aquifer. Aquifer level change can and does cause isostatic sea level change.
The authors and reviewers of this latest hockey stick paper are clearly not competent earth scientists. No competent earth scientist would have overlooked what was glaringly obvious to me and I’m not even an earth scientist just a well-read layman.
Willis
Kemp et al state in their conclusions:
“According to our analysis, North Carolina sea level was stable from BC 100 to AD 950. …rose at a rate of 0.6 mm/y from about AD 950 to 1400 as a consequence of Medieval warmth, …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.”
Where do you get 200 mm in 50 years? The data shows that rise in 100+ years, due to the 2.1 mm/year rate Kemp indicates.
I can find no statement in Kemp et al of a 5 mm/year increase, as you claim – can you please point out where this is stated?
The problem with salt marsh sediments is that they only record when sea level is rising, and have now way of recording when it is falling. So it is no big surprise that you can take a core at 80cm depth and get carbon dating at 1600yrs and 1800yrs simultaneously. All it means is that sea level was probably more or less the same over that period. So if you can’t measure any increase in sea level over a 200year period, the tehnique can’t be very good can it?
RoHa says:
June 26, 2011 at 5:24 pm
O.K. Time for the easy version again.
Is sea level going up, down, or sideways?
Inquiring minds want to know.
All three. Especially in a force 9 or above.
Hoser says:
June 26, 2011 at 9:15 am
Consider this little guy:
http://www.vims.edu/~jeff/fiddler.htm
Read it all.
Anyone whose ever visited the salt marshes will know that these things are everywhere.
@KR
“I can find no statement in Kemp et al of a 5 mm/year increase”
It’s derived from the graph. The last 2 dots are in 1990 and 2000 with a 50mm difference between them, i.e. 5mm/yr. This is more than double previous claims from Team AGW based on tide guage data.
RE: Carbon dating,
I see three issues.
1) given the nature of the area, the odds of a smooth top down distribution of samples, oldest on the bottom, youngest on the top, is problematic at best. Storms churning up the sand, in between storms, animals churning up the sand.
2) I’ve always read that it was improper to do C14 dating on entities that grew in water. This is because of the accumulation of CO2 in the water. BOth from the air, and from sediments washed into the water. Water will always contain a complete mish mash of both young and old CO2, so the ration of C12 to C14 is completely unpredictable.
3) Many of their samples are taken after the beginning of the Industrial Revolution. All of that ancient carbon released into the air makes any attempt at C14 dating meaningless at best.
@KR
By the way, if you really want to see how useless this proxy is then take a look at figure S6 of the original source paper (in the supporting literature) which from 1900 in effect shows the tide guage data superimposed on the salt marsh proxy. The tide guage data (which is tightly constrained in its error bands) is roughly linear from 1900 to 2000 whilst the salt marsh proxy shows a “hockey stick” curve totally absent from the measured data. It can hardly be said to be predictive therefore.
Ryan @ 71
I looked at Fig. S6 – the North Carolina data, a pretty smoothed out curve from the 193 points of data, is still within 1-1.5 standard deviations of the tidal gauge data. The tidal gauge data is well constrained, the NC reconstruction much less so.
In terms of predictive capability, I would definitely go with the tidal gauge data, as it’s far more precise. But in terms of long term reconstruction of the last 2K years, I believe (just my opinion, mind you) that the point of the paper is to establish that foraminiferal data provides a reasonable estimate. And that longer term sea level rise rates do correspond to best estimates of past temperatures.
“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.”
Two possible explanations jump out:
1. A centuries long period of extremely slow sediment depositation. That’s probably not impossible.
2. The samples are from ‘lag deposits’ (aka ‘Tempestites’). Lag deposits form when something — often a tropical storm — reworks sediments, eroding fine material and concentrating the coarser/denser material in a layer at the base of the redeposited sediment. Some lag deposits are widely known because the concentrated material is spectacularly rich in vertebrate bones and teeth — i.e. it forms a ‘bone bed’. It’d be hard to overlook a real bone bed type deposit, but maybe these lag deposits — if that’s what they are — are less obvious.
If I recall correctly, there isn’t much discussion of the geology/geological setting in the Kemp paper.
I try to restrain myself from posting comments on these sea level threads, but occasionally my sense of frustration overwhelms my personal resignation to being a lone voice in the wilderness and I am moved to try again.
It is entirely pointless to engage in these tendentious disputes about whose millimeter or tenth of a millimeter speculations about what the global sea level is doing, because measuring the the sea level to that kind of precision both a logical and physical impossibility.
I have linked to this document on numerous occasions
http://www.osdpd.noaa.gov/ml/ocean/J2_handbook_v1-3_no_rev.pdf
It is the data product handbook for the Jason-2 satellite which is the latest and greatest of the satellites which have provided the altimetry data for all those lovely graph of how GMSL has been proceeding upward at of 3mm/yr for thirty years. Due to continuing improvements in the technology it is probably at least an order of magnitude better, and more likely two, than the TOPEX/ POSEIDON units from the beginning of the record. When it comes to accuracy the handbook has this to say
2.3.1. Accuracy of Sea-level Measurements
Generally speaking OSTM/Jason-2 has been specified based on the Jason-1 state of the art,
including improvements in payload technology, data processing and algorithms or ancillary data
(e.g: precise orbit determination and meteorological model accuracy). The sea-surface height shall be provided with a globally averaged RMS accuracy of 3.4 cm (1 sigma), or better, assuming 1 second averages.
Even that claim is likely a statistician’s fantasy, because they also admit to not being able to determine significant wave height to better than 0.4 METERS! Since significant waves are present over most of the world’s oceans most of the time, I find there accuracy claims a bit difficult to resolve.
But aside from the technical difficulties involved in the metrology, which have admittedly been subject to profound improvements, there still exists a fundamental logical conundrum when it comes to attempting to measure GMSL. When you have an object isolated in space, it is possible to measure its dimensions with incredible precision, but GMSL is a measurement of height which by definition must be made in reference to some fixed datum and their is nothing on the actual physical planet that is reliably fixed at the millimeter level. Archimedes is widely misquoted as saying “Give me a lever and a place to stand and I’ll move the world”. When it comes to measuring GMSL we suffer from the same problem as Archimedes, there is literally no place to stand to make the measurement.
The current sats are tied into the GPS satellite fleet in ways that greatly increase the accuracy of their orbital ephemeris but the whole system is still referenced off ground sites which are subject to their own displacements, which are supposedly accounted for based on measurements from the GPS sats that they are referencing. It’s equivalent to setting up a contractor’s level in a row boat and trying to take readings off a level rod that’s in another rowboat, at least at the millimeter level of precision they are claiming to achieve.
To get around this both systems are actually based off the reference ellipsoid and the geoid, two completely arbitrary and artificial human constructs which are only vaguely related to the physical reality of the planet. The sea level anomalies posted in the data are actually anomalies from the reference ellipsoid and the undulations of the geoid, and since the advent of the GRACE and GOCE satellites has demonstrated that the geoid is neither constant or well modeled, the geoid model they are using now is significantly different from the one used at the beginning of the record. Even if we were able to magically surmount all these difficulties and arrive at an accurate measure of the Global Mean Sea Level, it would still be worthless information because the seas are not level and changes in the global mean will tell us nothing reliable about what will happen at any particular piece of local coast. I could go on much longer but my anger has dissipated and I’m running out of rhetorical gas, but just for my sake can we give it a rest.
KR says:
June 27, 2011 at 7:05 am
Hi, KR. They were careful not to state it anywhere. As I said in the head post, they haven’t released their actual results for the “Summary of North Carolina Sea Level Reconstruction”. Because of that, I had to digitize them from their Figures.
This is all too typical of AGW activists like Mann. They’re willing to give you vague generalities like “the mean rate was 2.1 mm/y in response to 20th Century warming”, trusting that folks won’t go through the hassle of asking them for the data or even thinking about things too closely. And all too often in the past they’ve been right, people didn’t pay much attention. Now, we do.
As an example of thinking about things closely, they show a rapidly accelerating rate of sea level rise throughout the 20th century … so, KR, if the average over time is a bit over two, and it is rising exponentially, shouldn’t we expect that the final values will be a bit more than twice the mean value? And guess what? It’s just under 5. … But there’s not an observational dataset anywhere that supports that, including their own proxy results.
So if you wait for them to announce that their ballyhoo’d results don’t agree with observations, you’ll have a long wait. That’s the kind of thing you either have to find out for yourself, or wait for someone like me (or you if you’re willing to think critically about climate claims) to notice, that their results are way off the rails.
w.
PS – I also suspect that they are moving the pea under the thimble a bit in their statement above. I think the first part refers to the trends of their “Summary of North Carolina Sea Level Reconstruction” line, while the final sentence refers to the trends of the individual data points in the 20th century shown in Figure 1 of my previous post.
Willis
I found out (by, gasp, asking one of the authors) that the authors had submitted additional information and code, but that PNAS hasn’t linked it to the article yet – they are working on that. I believe it’s reproducible without that extra data, but I do understand that mileage may vary.
The curve you are looking at is a very low order polynomial fit to the assorted data – the steep curve in the end of the 20th century is a result of fitting it to the severe change in slope at the end of the 19th century, and hence the overshoot at 2010. I personally would have preferred them to place four linear fits to the different slopes they had identified, based upon breakpoint analysis, but given that some of the changes (MWP, LIA) weren’t all that abrupt, I would have to play more with the stats to see which gave a better fit.
Table S1 in the supplemental data does give the raw values with variances, albeit without the GIA and site offsets – it’s not that hard to drop that into Excel and reproduce the raw datapoint curve and do your own fits.
—
My biggest issues with this column, and with your previous post on the subject, is that rather than starting from the assumption that the authors (of which Mann is again 4th of 6, not the lead) were honestly presenting data, you led out with innuendo and accusations of malfeasance. Where you had questions or points that you thought lacked clarity, you did not ask the authors for clarification (yes, I know you and Mann don’t get along, but there are 6 authors here), or read the references, or look at similar literature (all basic methods for clarifying what you are reading), but instead proceeded with more innuendo and accusations. The transfer function you complained about in the previous post, for example? Reference number 7, fully detailed, yet you didn’t bother to check the references, and just claimed it to be undisclosed with more innuendo. Yes, you would have to pay to read the article where it was published – not all journals are free, and everyone I know has to cough up the subscription prices for numerous journals to keep current.
You simply and straightforwardly attacked a paper due to (in my opinion) who one of the authors was, and because it presented a ‘hockey stick’ – regardless of the fact that the data was processed in a well established fashion for sea level reconstructions. That’s not science, Willis – that’s an agenda.
Given that approach, I really don’t expect you to treat the authors, their methods, or their data with any actual consideration of what’s presented, but rather with more polemic. I have to say that I’ve seen much better from you, and have enjoyed previous discussions on this site – I am quite disappointed.
RoHa says:
June 26, 2011 at 5:24 pm
“O.K. Time for the easy version again.
Is sea level going up, down, or sideways?
Inquiring minds want to know.”
It’s only the sand that’s going up, down, and sideways; with every good storm. The C14 samples only tell us that warmmongers do not possess inquiring minds. In fact, I doubt any warmer will dare to take more than a cursory dismissive glance at this page. Even the trolls won’t touch it.
KR: “In terms of predictive capability, I would definitely go with the tidal gauge data, as it’s far more precise. But in terms of long term reconstruction of the last 2K years, I believe (just my opinion, mind you) that the point of the paper is to establish that foraminiferal data provides a reasonable estimate.”
I think that you can clearly see that it has NO capability for hindcasting since you can look at the tide gauge data for the last 100 years and if you had used the North Carolina data and zeroed it for the present day then by 1900 you would already be seeing a drop of 50% more than the real measured data. If it is 50% out in hindcasting over 100 years then how accurate will it be after 2000 yrs????? You couldn’t use this data to give any clue about the sea level – you couldn’t even tell if the sea level was higher or lower (and this is BEFORE we get into the size of those massive error bars – bearing in mind that you need to go out BEYOND those marked to reach just a 90% confidence interval).
It really is time you opened your mind to the possibility that this paper is a pile of bull-crap.
I make you the same offer I made the others. Come back with the details of their three “transfer functions” and their raw data, and we can move forward. Your claim that it is reproducible without complete details of their methods and their data lacks credibility.
And blaming the lack of archiving on PNAS? Very weak … the archive for these datasets exists already, and responsible authors know that and accordingly they archive the data themselves. Blame PNAS because they haven’t archived their own data? It is to laugh … and not only that, but you believed their excuse and didn’t pursue it any further. Another successful interaction in the world of climate science obfuscation, you came away as empty-handed as you arrived but you think you got something … “(gasp)”, as you say, indeed.
Yes, and you might even believe that they chose that particular polynomial fit by chance or something, rather than picking it because of its “ski-jump” shape. Others of us are more … well let me say “cautious” in these matters.
But my point stands. Regardless of exactly how they did it, they have produced a reconstruction which does an abysmal job of “reconstructing” present temperatures … and your advice is to just ignore that? Why on earth should I ignore it?
KR, since their whiz-bang “Summary of North Carolina Sea Level Reconstructions” gets the present horribly wrong, I think I’ll pass on believing what it says about two thousand years ago. Perhaps you can explain how a reconstruction that does a very bad job reconstructing today should be believed regarding yesterday … but until you do explain that, I’ll say that if it gets today wrong there is absolutely no reason to believe it about the past.
I see that part of the problem is that you are conflating “raw data” with “results”. Raw data is their measurements. Results are what they think the measurements mean. So no, Table S1 doesn’t give the raw data. It gives some of their results. To date they have published neither the raw data nor the “Summary Reconstruction”.
I assume nothing, I look at the past. Michael Mann has lied, concealed critical parts of his work and data, and destroyed evidence. Given that history, if you start out with any other assumption about anything his name is on, you are being unbelievably naive. And anyone who wants Mr. “Delete the Emails” Mann, Mr. “CENSORED_TO_1400” Mann, Mr. “Asking me for my data is intimidation” Mann on their scientific team is equally irresponsible.
So yes, call me crazy but I do expect Michael Mann to do as he did in the past. Do you have any information that he’s changed his ways, or turned over a new leaf? Because if not, you’re a fool not to suspect him and the people he works with of putting their thumb on the scales.
And that’s not my “assumption”. That’s an honest reading of Mann’s documented history. You can start out by assuming Mann is honest if you wish … me, I like to stick closer to the facts.
I looked at both the references and the similar literature. And no, reference number 7 did not give the details of the three transfer functions that they used in the Kemp 2011 study. If you think that they are in reference number 7, I invite you to tell us exactly what the three transfer functions are, and how the three transfer functions differ from each other … I await your answer. However, I fear that you’ll neither admit you were wrong, nor will you be able to produce the three transfer functions and point out their differences. So surprise me.
Oh, please, stop attacking my motives, KR. You don’t have a clue about my motives, and you just look petty when you attack them. I discussed the paper and came to negative conclusions for several perfectly valid scientific reasons.
1. Lack of transparency. They didn’t publish their data. They didn’t publish their code. They didn’t publish their “transfer functions” (despite your claims to the contrary). They didn’t publish their results for the “Summary Reconstruction. They separated out the GIA and other errors rather than adding them all together to give a total error (making it look like their errors are smaller than they are).
2. Results that do not agree with reality. Their “Summary Reconstruction” claims a sea level rise of 8″ since 1950, and says that the rate of sea level rise has been above 3mm per year since 1950 and is now 5mm per year.
3. Poor choice of location. Why would anyone try to establish sea level in an shifting maze of islands and marshes, some sinking and some rising, with changing salinity and varying tidal ranges, in an area where GIA is a huge issue and the nearest long-term tidal records disagree strongly? Is the light better there or something? *
4. Inadequate handling of the question of historical changes in tidal range (they assume there were none, when observations show that they are occurring as we speak in that very area). Their own data shows that the Sand Point site was like the mainland sites for hundreds of years … then like the barrier island sites for hundreds of years … then back to the mainland pattern. They claim these large changes in salinity occurred without any change in the tidal range, which seems very doubtful to me.
Now you might not agree with what I say are problems with their science … but claiming that I’m just making it all up because of a personal vendetta looks like an attempt on your part to avoid dealing with the issues. Might not be one … but that’s how it looks.
Deal with the facts and let your fantasies about my motives go. Do you think the location choice was good? Do you think they should have archived their data? Do you think we’ve seen six inches of sea level rise since 1950? Do you think there have been no changes in tidal range at Sand Point in 2,000 years, despite large changes in both the barrier islands and the channel between Sand Point and the mainland?
Those are the questions here, not whether my motives are pure or not.
Sorry to disappoint you … but attacking my motives means nothing about whether my scientific claims are correct. And arguing “ad hominem” like that just makes you look like you don’t think you can win by discussing the science.
To echo your words … I expect better from you than an ad hominem attack.
w.
PS – As I indicated somewhere above, I used to write to scientists regularly to ask them to archive their data. After a long string of unqualified failures using that method, these days any study where the authors haven’t already archived the data just gets rough treatment … so sue me. I’m done with begging scientists to follow the scientific method. If they don’t follow it, I no longer write them. I just point out, very publicly, that they are not following the scientific method. It’s not like they haven’t been warned, the necessity of archiving of data has been highlighted many times. And as I said, the fact that the PNAS vanity press doesn’t require that may be why they published there (along with the total lack of critical peer review).
I do note that you wrote the authors … and what did you get, KR?
Did you get any data? Did they actually reveal anything? Did they send you their code, or reveal their transfer functions?
Not according to your account. According to you, all they did was blame PNAS … you may want to reconsider your actual results from writing to them. After far too much of that same kind of excuses and tap-dancing, you might see why I’ve given up on that path. I say publish [the code and data] or perish.
PPS – * “Is the light better there” refers to an old Sufi story. A man is wandering around under a street light looking down at the ground. A bystander asks what he’s doing. “I dropped my house keys.” The bystander helps him look for a while and when they don’t find the keys he says, “Are you sure you dropped them here by the street lamp?”
“No,” the man replies, “I lost them down the street, but the light is so much better here”
Willis – Sadly, just the polemical response I expected.
Another successful interaction in the world of climate science obfuscation…
…you might even believe that they chose that particular polynomial fit by chance or something, rather than picking it because of its “ski-jump” shape. Rather than a better statistical fit across the several thousand years with minimum assumptions? Hmmm….
Michael Mann has lied, concealed critical parts of his work and data, and destroyed evidence.
And no, reference number 7 did not give the details of the three transfer functions that they used in the Kemp 2011 study. Actually, it specifically gave the depth/species ratios you were whining about as ‘made up’ in your last post.
Lack of transparency. They didn’t publish their data. They didn’t publish their code. They didn’t publish their “transfer functions” (despite your claims to the contrary). Heh. Give it a week or so on the ‘code’ publishing – the author I contacted, Vermeer, was quite surprised that the data wasn’t linked yet. And the transfer function you complained about is published – in a clear reference you apparently hadn’t looked at until I mentioned it. Besides – reading the paper, I believe I could (with some time in the swamps) replicate and test this paper’s results, the major real concern with a well written paper.
[various complaints about the science] It’s clear that you have either (a) not read the methods, or (b) do not understand them. The authors have specifically addressed concerns about GIA, wetland modification, etc., using methods standard to the field of Foraminifera sea level reconstructions, but you are simply emphasizing uncertainties without addressing how the authors approached them. Weak sauce…
So yes – I have questioned your motives, based upon what you have written – an attack post lacking in scientific content. As I said before, you have attacked a paper by Kemp et al (with Mann a contributing, but not lead author) on sea level from paleo records with additional work to see how it matches up to temperature reconstructions – apparently (since I don’t read minds) because one of the authors is a convenient Ad Hominem target, and more importantly because it clearly indicates climate change. Again – not science, but polemic. And the scientific validity of polemic is, well, zero.
KR, you keep making claims about the availability of enough information for replication, you definitely talk a good fight.
Yet when I ask the simplest of questions (what are the Kemp three transfer functions and the differences between them) you waffle, you duck and weave, you pronounce from on high, you make claims about what I have read, you question my motives and make scurrilous attacks …
But where are the details of the three transfer functions, KR? You’re great at making unsupported claims, and you are clearly expert at spewing all kinds of nasty innuendoes and ad hominem attacks, but when it comes to describing the transfer functions you suddenly develop lockjaw that’s as total as that of the authors …
Funny, that.
w.
PS – Stop the bullsh*t about how “the transfer function [I] complained about is published – in a clear reference you apparently hadn’t looked at until I mentioned it.” You can say that over and over, it proves nothing.
As I told you when you made that claim before, if that is so, then PRODUCE THE THREE TRANSFER FUNCTIONS and explain the differences between them. Anything else is just handwaving.
KR says:
June 28, 2011 at 6:13 pm
Actually, that’s just nasty misinformation from your dark fantasies. Do a search on “made up” in my last post, and what do you find? Nothing. The only thing “made up” is your specious claim. I didn’t say they made things up. I said they ignored things, and that they re-used the Tiljander proxies upside down again in the most laughable long-running scientific idiocies on record. I said that they should archive their data and code. But I didn’t accuse them of making things up, that’s on you.
Thanks for the opportunity to cite my last post, though, some folks might not have read it. I love free publicity like that.
w.
Has there been any research on how tectonic plate movement might influence sea level?
My guess, is that most of the change measured, can be explained that way…
Makes a lot more sense than temperature at least…
KR: you know something, I agree with you on the Dr Mann thing. Kemp et al. have put their own names to this pile of poop and therefore they are all tarred with the same brush. It is unfair to single out Dr Mann as being particularly corrupt in this case – the whole team on this paper are liars.
Normal practice in attempting to use a proxy to extend our understanding of something outside the instrumental record would be to ensure the proxy fits well within the period of the instrumental period. This is something they have bent over backwards to avoid doing with all manner of graphs that attempt to obscure the truth by failing to superimpose the hindcasts as they should. Figure S6 of the supporting document is as close as they get to showing it done properly and it shows that the proxy is widely inaccurate going back 100 yrs. It can’t possibly be relied upon to hindcast back 2000years – that should have been the only conclusion of the paper but they claimed the opposite. They are LIARS. All of them are LIARS. There is plenty of reason to believe that the way the paper has been presented is to cover up the fact it is based on a LIE, from the way they have tried to obscure the weakness of the proxy to hindcast within the instrumental period to the way they have tried to use change point regression analysis in a manner in which it can’t be reliably used, to the way they have used claimed “tide gauge data” which is actually 50% computer modelling based on assumed global temperatures, to the way they sought to avoid a genuine peer review process.
This paper is a travesty of the truth. It should be studied and picked apart by anybody with an interest in the truth until every lie within it has been exposed. It should be held up as a tragic example of how low certain scientists will stoop to promote certain false ideas. It should be used to pillory all the scientists that had the audacity to put their names to it. These people should never have the right to put their name to any scientific paper ever again, let alone any paper that is specific related to AGW. They are condemned by their own words and actions.
Willis,
The earliest mention I can find of the transfer functions is this Horton et al 2006 paper (no Kemp). No SI. Free download from NC state site:
http://dcm2.enr.state.nc.us/slr/Horton%20et%20al%202006%20diatoms.pdf
Discussion section is about development and use, lots of details, type of transfer function used mentioned, but the elusive actual transfer function isn’t there. From the conclusions:
There is mention of assorted caveats with using the method, and possible “cherry picking” among parameters for the best results which might be justified. Well, they say they were first, thus I shall presume the usual warnings against using the “first of” something apply.
This was referenced by:
Engelhart, S.E., B.P. Horton, and A.C. Kemp. 2011. Holocene sea level changes along the United States’ Atlantic Coast. Oceanography 24(2):70–79, doi:10.5670/oceanog.2011.28.
Free download, no SI. Transfer functions not mentioned by name, but much discussion of the methodology of relative sea level (RSL) reconstructions with math on error calculations. From the Concluding Remarks:
Hope this helps.
Curious. Someone comes up with something “new” and “scientific,” and from that comes a rotating assemblage of co-authors churning out a nigh-endless stream of numerous papers for numerous journals which are basically just different presentations of the same data. Has such credential-padding long been a behavior in science, or is this an example of the spreading of Hockey Team Publishing Syndrome?
Re: my previous post:
Sure, after I proofread it ten times and finally posted, I see in the first quoted section that when I corrected the mush from the bad copy-and-paste from the pdf (multiple columns mash together), I somehow duplicated some text while goofing it a bit. Oh well, mistake noted, original source with correct text linked and available.
kadaka (KD Knoebel) says:
June 29, 2011 at 5:22 am
Thanks, KD. I’ve tried tracing the paper’s claims back in various forms and forums. Lots of general mentions of the transfer functions … but no details of any of the actual transfer functions used by Kemp et al. Despite that, some people here keep claiming that there’s enough info to see if the authors made any mistakes, and that the transfer functions are in fact available … but they are strangely unable to produce the actual functions.
w.
Willis,
I’m beginning to think these “transfer functions” are not something that can be printed out and analyzed. Following the Horton trail I found this 2005 paper, free download of this “postprint” version (note: link given for data repository on pg 30 doesn’t work):
http://repository.upenn.edu/ees_papers/39/
From page 11:
Reference citation:
Searching by the names yielded many mentions of the program with different version numbers, years (<2000), and often "unpublished software." It's apparently discipline-specific and used to make educated guesses about environmental variables like moisture and salinity based on the amounts of assorted micro-critters like diatoms.
Just tonight I Googled this (used only "Juggins", didn't see this with both names):
http://www.staff.ncl.ac.uk/staff/stephen.juggins/software.htm
CALIBRATE was an old DOS program by Juggins, elsewhere I've seen it mentioned as a C++ program. Some time ago it was replaced by C2, Windoze (XP, Vista), which also replaces another program mentioned in that Horton paper (M.A.T.). Free download and use, limitation is max 75 samples without license.
Thus the vaunted "transfer functions" may be nothing more than an input file of a proprietary format used for a piece of proprietary software. Black box functioning, just the results for output. Also, see this discussion. Alternatives in R and something called “paltran” are mentioned, one R package is “rioja” which is also by Juggins. But, the paltran version doing WA-PLS gives different results than rioja or C2. Not a good sign when a method can’t be properly replicated by others.
The WA-PLS method was laid out in much mathematical detail in a much-cited book chapter circa 1993 (Hydrobiologia), link to paywall of just that chapter. But what appears to be the same chapter appeared in another book (Multivariate Environmental Statistics), free download of chapter:
http://www.biometris.wur.nl/NR/rdonlyres/71EBBDE7-DE7B-4956-9BEA-2B807C34A8EF/52117/terBraak1993JugginsBirksVoetWAPLS.pdf
So if you could acquire the “transfer functions” you may just have some files for an old piece of DOS software that you’d also have to dig up, and still not know exactly what was being done without getting the source code or much likely-verboten reverse software engineering. Going by the licensing of C2 and the Kemp2011 SI saying the North Carolina dataset has 193 surface samples, you may also need the paid-for version which might not be available if you need the original CALIBRATE program.
You may have better luck waiting for KR to provide that “freely available” info. 😉
Willis, FYI:
Just stumbled upon this thread … over at Prof. Rahmstorf’s blog ‘KlimaLounge’ he pointed me to an archive of data and code since I was interested in the proxy-DCA too:
http://www.pik-potsdam.de/sealevel/en/data.html
Unfortunately the Kemp reconstruction part is missing from the archive (confined to the results of his RSL reconstruction) so I guess they’ve documented their part of the work package. I just asked Rahmstorf wether he knows if Kemp will fill in his part of the documentation as well.
Anyway let’s wait and see what will be available when they’ve finished adjusting the documentation part of the paper.
Wolfgang Flamme says:
July 1, 2011 at 6:58 pm
Yes, I’m still waiting for the input data and code for the Kemp sea level reconstruction. They’ve given the outputs of that reconstruction but not the inputs.
w.