Buy

Books
Click images for more details

Support

 

Twitter
Recent comments
Recent posts
Currently discussing
Links

A few sites I've stumbled across recently....

Powered by Squarespace
« Non-blogging | Main | Speccy on Beddington »
Friday
Jul222011

John Droz on sea level

John Droz, writing at WUWT, has a very interesting article on a battle of wits over sea level rise. As I noted after the Cambridge Conference, I have made a mental note to pay more attention to this aspect of the global warming debate. There are some remarkable stories in this area. The conclusions of the paper Droz is writing about are startling enough

To reach the multimeter levels projected for 2100 by RV requires large positive accelerations that are one to two orders of magnitude greater than those yet observed in sea-level data.

The story of the counterarguments from Profs Rahmstorf and Vermeer is rather remarkable too.

 

PrintView Printer Friendly Version

Reader Comments (71)

Please can somebody explain how it is possible to discover an acceleration trend measured in hundredths of millimetres per year per year, when the basic data goes up and down by about 4500 (15 feet) every twelve and a bit hours because of the tides. And even that figure varies by 20% within a fortnight.

I have long thought about this problem and have never seen a satisfactory answer, Simply put, I don't believe that it is possible. Perhaps someone can explain how it's done.

Jul 22, 2011 at 8:09 AM | Unregistered CommenterLatimer Alder

You can do it by recording the peaks over a long period of time, once you have enough data you can remove the noise and reveal the trends.

What is much more intertesting is how Rahmstorf and Vermeer are arguing with a straight face that the outputs of their Model showing an accelerating sea level increase trump observational data showing a deaccelerating sea level increase.

Just one more example of observational data which does not support the data being ignored and the Model outputs being tooted as fact. Surreal.

Jul 22, 2011 at 8:19 AM | Unregistered CommenterBreath of Fresh Air

There is acceleration indeed, but in the way they try to artificially "hide the decline"! Earlier this year, University of Colorado managed to apply an artificial up correction to the satellite sea level measurements. Now, it has done it again. When real sea level measures are going down, they introduced another correction, and imagine: the sea level rise rate went up!!!
Please see the details at:
http://ecotretas.blogspot.com/2011/07/more-hiding-decline.html

Ecoretas

Jul 22, 2011 at 8:28 AM | Unregistered CommenterEcotretas

Yet old tide gauges are parked at the seaside and speak little of sea level change in the oceans.

Similar questions could be asked about sources and sinks of CO2. How is the growth of the biosphere or the emissions from the seas measured and how accurate might they be? Human emissions may be but a fraction of their error bars...so I guess we do need the models because the data can't be trusted.

Jul 22, 2011 at 8:41 AM | Unregistered CommenterAlan Reed

Modelled projections are once again shown to be wrong by observation.


1. Global temperature projections are wrong.

2. Tropospheric temperature projections in the tropics are wrong.

3. Oceanic heat content projections are wrong.

4. Sea level projections are wrong.


It would appear that Climate Scientists are stuck in the lower levels of a horror computer game unable to save the virtual world they themselves have created.

CAGW is all in the mind.

Jul 22, 2011 at 9:37 AM | Unregistered CommenterMac

Rule one of climate science if the model and reality differ in value , its reality which is wrong .
When you have a rule like that you can see how they can not only come up with such figures but justify them too.

Jul 22, 2011 at 9:49 AM | Unregistered CommenterKnR

There's a recent article in The Australian reporting similar

Sea-level rises are slowing, tidal gauge records show
ONE of Australia's foremost experts on the relationship between climate change and sea levels has written a peer-reviewed paper concluding that rises in sea levels are "decelerating".

The analysis, by NSW principal coastal specialist Phil Watson, calls into question one of the key criteria for large-scale inundation around the Australian coast by 2100 -- the assumption of an accelerating rise in sea levels because of climate change.

http://bit.ly/qsMpJe

Jul 22, 2011 at 10:08 AM | Unregistered Commenterandyscrase

Hands up if your surprised that climate science fiction outweighs facts?

Well in the eyes of climate science fiction writers

Jul 22, 2011 at 10:50 AM | Unregistered CommenterShevva

Shevva:

Climate science fiction is a very good description of the consensus.

Jul 22, 2011 at 11:22 AM | Unregistered CommenterMac

I'm staying with the Hughes-Josh duck.

Jul 22, 2011 at 12:15 PM | Unregistered CommenterRoger Carr

I find it surprising that anyone is attempting to study sea level change using tide–gauge data.

As long ago as 1992, Professor Morner of Stockholm University wrote:

The mean global sea-level changes today and in the near past (and by that also in the near future) have not been able to establish in a satisfactory way, either by mathematical treatments of tide-gauge data, by geophysical modelling or by geological considerations.

He went on to propose a new method of studying sea level changes based on accurate measurement of the Earth's rotation:

We here propose a new means of studying global mean sea level; viz. changes in the Earth's rate of rotation (the variations in the length of the day). Any global change in sea level must be seen in the Earth's rate of rotation as this is a direct function of any change in its radius.

And he finishes:

The recording of LOD [length of day] changes is a powerful tool for monitoring and predicting global sea level changes.

Abstract available here: http://www.jstor.org/pss/4298049

It is now possible to measure the Earth's rotation with extremely high accuracy, so there ought to be no argument about the rate of sea level change.

Jul 22, 2011 at 12:58 PM | Unregistered CommenterScottie

Every time we look at the quality of climate science we find it's even 'worse than we thought'.

Jul 22, 2011 at 1:27 PM | Unregistered Commenterstan

Have we already forgotten that the sea levels are rising faster and faster but this is masked by the land rising as faster as well, opening up the basins and thus lowering the sea levels? So, you see, the sea levels are rising at an accelerating rate, but it cannot be measured either directly or by proxy via the length of the day, because the land is rising, opening up the sea basins to compensate. What is so hard to understand about that?

Jul 22, 2011 at 1:36 PM | Unregistered CommenterRedbone

Morner's article can be found at 'What We Agree On. posted May24 2011. Its well worth a read.

Jul 22, 2011 at 4:02 PM | Unregistered CommenterEddy

"Please can somebody explain how it is possible to discover an acceleration trend measured in hundredths of millimetres per year per year...."
Jul 22, 2011 at 8:09 AM | Latimer Alder

Models dear Latimer..dear Latimer...models dear Latimer....models...

(with apologies to http://www.youtube.com/watch?v=tlICWoBb5Ik&feature=related )

Seems rather apt and in these insane "green" times we must keep our sense of humour! I have said it before! Here in the Mediterranean some bu**er has a bucket!

Jul 22, 2011 at 4:05 PM | Unregistered CommenterPete H

oops! hope hat made it through Bish! Shpelling in my email wrong nut it got through!

Jul 22, 2011 at 4:06 PM | Unregistered CommenterPete H

Question: Why does anyone care about sea level if the problem is not in relation to coastal area?

Some folk seem to think this is an almost metaphysical concept, and that somehow actually measuring the sea level using tide gauges doesn't count.

Measuring LOD and implying sea level from that is lunacy - it tells you precisely nothing about whether the sea is encroaching or receding, which in my view as all anyone should care about.

Adding adjustments to cope with the ocean basins getting larger is equally mad - if this results in genuine reduction of levels, then good - report that fact for what it is, a FACT!

Jul 22, 2011 at 4:12 PM | Unregistered Commentersteveta_uk

Breath of Fresh Air

You can do it by recording the peaks over a long period of time, once you have enough data you can remove the noise and reveal the trends.

I assume you are being facetious, because there are far too many types of noise and errors to get the precision needed to see parts of a millimeter per year.

Models dear Latimer..dear Latimer...models dear Latimer....models...

The only reliable and sure way, Pete H. That is why it is the backbone of Climate Science [Fiction]. And you don't have get your feet wet to collect any data.

So, you see, the sea levels are rising at an accelerating rate, but it cannot be measured either directly or by proxy via the length of the day, because the land is rising, opening up the sea basins to compensate.

Exactly -- the land is actually a large duck and is following the Hughes-Josh Model. The nice thing about this model is you don't need a computer. All you need is a large basin, water and a rubber duckie. Then add a very large chunk of ice. The rubber duckie will rise as the ice melts [assuming that the ice block was large enough to not float when added and actually increases the level of water when melted].The land acts the same way.

Jul 22, 2011 at 4:31 PM | Unregistered CommenterDon Pableo de la Sierra

What an amazing coincidence...

Sea levels are rising.

Land levels are rising.

This happens in such a way that the two exactly cancel each other out and the planet's diameter remains constant, so Length of Day is unaffected.

Isn't science fun in the Alice in Wonderland world of climate science!!!

Jul 22, 2011 at 4:48 PM | Unregistered CommenterScottie

Scottie, the other coincidence is that chinese power stations are churning out massive amounts of CO2 causing catastrophic global warming, but at the same time are churning out sulphur that has a cooling effect that exactly cancels out the warming :)

Jul 22, 2011 at 5:17 PM | Unregistered CommenterPaulM

I saw a 3D map of the globe some time ago with an exaggerated vertical (surface) scale, so that variations in land and sea level were more obvious. Because of gravitational anomalies, the sea surface was anything but smooth, with tens, possibly hundreds of metres difference between the oceans. It seemed a bigger potential source of variation than anything the climatologists have proposed...

Jul 22, 2011 at 5:19 PM | Unregistered CommenterJames P

Chris Huhne in the news again:

http://www.independent.co.uk/

Chris Huhne quizzed again over speeding new

Energy Secretary questioned over claims that he made his ex-wife take speeding points for him.

* Police let witness visit brothel and take heroin

Not clear if the second point is connected ;)

Jul 22, 2011 at 5:33 PM | Unregistered Commentersteveta_uk

Measurement of a wobbly surface (waves & tides) on a wobbly thing (length of day, planetary motions) by a wobbly gadget (orbit errors, gravity model) referenced to a moving thing (tide gauge inaccuracies, land subsidence/heave) can show teeny-tiny changes in no time at all really and the news is bad......

Jul 22, 2011 at 6:01 PM | Unregistered Commentersimpleseekeraftertruth

"The recording of LOD [length of day] changes is a powerful tool for monitoring and predicting global sea level changes." It is now possible to measure the Earth's rotation with extremely high accuracy, so there ought to be no argument about the rate of sea level change.--Scottie

But what about the Pacific Warm Pool 'bulge' (ENSO driven)? Wouldn't that affect LOD?

"I saw a 3D map of the globe some time ago with an exaggerated vertical (surface) scale, so that variations in land and sea level were more obvious. Because of gravitational anomalies, the sea surface was anything but smooth, with tens, possibly hundreds of metres difference between the oceans. It seemed a bigger potential source of variation than anything the climatologists have proposed..."--James P

Better take another look at that map.

Jul 22, 2011 at 6:10 PM | Unregistered Commenterjorgekafkazar

Has any climatologist yet managed to identify a piece of land that is now submerged due to sea level rise in the last 10-20 years? Or is even threatened?

Jul 22, 2011 at 6:22 PM | Unregistered Commentergolf charley

golf charley;

"Or even threatened?"

Not a lot really and none so far.

Jul 22, 2011 at 6:36 PM | Unregistered Commentersimpleseekeraftertruth

jorgekafkazar:
"But what about the Pacific Warm Pool 'bulge' (ENSO driven)? Wouldn't that affect LOD?"

In his 1992 paper, professor Nils Morner acknowledged there could be other explanations, but he concluded for such an explanation to be correct, it would imply there had been no global rise in sea levels during the last 150 years.

The decadal changes in rotation swing around a sinusoidal, about century long, mean trend that might represent such a global sea level factor. This factor is consistent with a sea level rise in the order of 11 cm in 100 years (which is a fraction of often claimed values for the hypothetical greenhouse generated sea level rise today and in the near future).

This can be taken as a measure of the maximum possible rise in global mean sea level during the last 150 years. It can, however, not be excluded that it represents the interchange of angular momentum with a more slowly moving oceanic intermediate or bottom water currents. If so, there would be no significant global rise in mean sea level during the last 150 years.

Jul 22, 2011 at 6:43 PM | Unregistered CommenterScottie

"It is now possible to measure the Earth's rotation with extremely high accuracy"

Didn't John Harrison invent such a device? I think I've got one on my wrist...

WRT Huhne speeding, I find it hard to believe that the police are having such trouble investigating it. Surely it's a simple matter of record when he was booked and who got the penalty points?

Jul 22, 2011 at 7:27 PM | Unregistered CommenterJames P

All these comments about sea and land levels rising remind me of a program I saw on TV just last week. It was all about Sweden and my wife and I really enjoyed it.

The program commentator was with a Swedish guide on top of a hill, on an island.

The guide commented that all the land had been covered by ice during the last glacial period.

Then she said, that the hill they were standing on had risen 268 mtrs since the ice retreated and in fact it is still rising!

No mention of global warming was made. Isn't nature wonderful?

And I hope I'm not around during the next glacial.

Jul 22, 2011 at 7:34 PM | Unregistered CommenterPeter Walsh

@golf charley

Whale-Skate Island:

http://en.wikipedia.org/wiki/French_Frigate_Shoals

Jul 22, 2011 at 8:21 PM | Unregistered CommenterBilly Liar

Jul 22, 2011 at 7:34 PM | Peter Walsh

That was coast on the dreaded BBC channel. Their other favorite messiah, Prof Cox, also made some really interesting comments in his series for them when he suggested that climate had been warmer in the past and that it changed continually. The potato producer-director didn't realise what he ahd said though, it was toooooo subtle for her. Have you noticed how many hers there in senior positions at the BBC? particularly for documentary programs.

Jul 22, 2011 at 9:38 PM | Unregistered Commenterstephen richards

When we determine rates of sea level rise, we do not calculate it year by year. As highlighted by the reply by Bob Dean and John Houston, we need to consider the average rates over long periods to reduce the impact of noise.
Think of the problem as measuring the thickness of a page in a book. Rather than trying to directly measure one page, we measure the thickness of a chunk of pages and divide by the number of pages. The bigger the chunk of pages we measure, the more confidence we tend to have that we have a good estimate of the page thickness. Unfortunately, some seem to think that they have a fancy system that can remotely sense the thickness of the page from its' ability to insulate the fish and chips, and from that they can extrapolate to the book thickness

Jul 22, 2011 at 10:50 PM | Unregistered CommenterWillem de Lange

Billy Liar, thanks for the link, but it mentions coastal erosion being the cause.........

South and East coasts in the UK are in retreat, but that is also erosion not sea level rise.

The historic "cinque ports" were abandoned because they "silted up". Doesn't that suggest a change in climate, ie less rain to keep the harbours free of sediment? Or a fall in sea level, or even a rise in land level?

Jul 22, 2011 at 11:30 PM | Unregistered Commentergolf charley

@golf charlie

It's just a sand dune in the sea; you know that, I know that, but it doesn't stop the climate change fetishists from attributing its coming and going to sea level rise.

http://www.heatisonline.org/contentserver/objecthandlers/index.cfm?ID=4658&Method=Full&PageCall=&Title=Hawaii%20Sees%20Varied%20Impacts%20of%20Climate%20Change&Cache=False

There is an information board put up by Hampshire County Council at Titchfield Haven which says something along the lines of 'The village of West(?) Wittering was lost to the sea in Saxon times'. Sea level rise, land falling or longshore drift? You choose.

Personally, I think sea level has been both higher and lower than at present on the south coast of the UK in the last 2000 years.

Jul 23, 2011 at 12:29 AM | Unregistered CommenterBilly Liar

James P Jul 22, 2011 at 7:27 PM

"WRT Huhne speeding, I find it hard to believe that the police are having such trouble investigating it. Surely it's a simple matter of record when he was booked and who got the penalty points?"

Perhaps they have been instructed to persue the investigation with the same dilligence that they were originally told to persue the hacking scandal ;)

Jul 23, 2011 at 7:28 AM | Unregistered CommenterPFM

@breath of fresh air

'You can do it by recording the peaks over a long period of time, once you have enough data you can remove the noise and reveal the trends'

H'mm

As a generic statement about finding signals in noisy data, I'm sure you are right.

But tide gauges record to the nearest centimetre. Even asssuming that you could accurately adjust fro all the noise (and weather conditions affect the tidal height quite a lot), how do you get to an acceleration measured in hundredths of a millimetre? A thousand times smaller than the resolution of your basic measuring instrument, and several million times smaller than the semidiurnal variation of the basic data.

Note also that even the most accurate tide gauge can only take about 75,000 readings of high tide per century. and the supposed 'acceleration; will only have begun to occur in the last 25,000 of those.

I make no claims to be a signal processing expert (I'm a Chemist by training) , but the orders of magnitude here seem quite awry. Please convince me that such accuracy is actually possible.

Jul 23, 2011 at 7:31 AM | Unregistered CommenterLatimer Alder

@golf charley

'The historic "cinque ports" were abandoned because they "silted up".

So the cinque ports were very badly named. They didn't sink at all. Exactly the opposite.

(Sorry :-( .. .Nurse! ..More coffee for Mr Alder! Intravenous if needed)

Jul 23, 2011 at 7:35 AM | Unregistered CommenterLatimer Alder

Most sea level experts disagree with Rahmstorf - the general view is that SLR doesn't relate neatly to global mean temperature, and his projections are generally held to be rather extreme by the mainstream climate science community.

Jul 23, 2011 at 10:59 AM | Unregistered CommenterRichard Betts

Richard Betts, Latimer and Billy Liar

Rahmsstorf smacks of dubious statistical selection and manipulation to support a theory for which there is no real world evidence.

I am a yottie, and have sailed in waters relying on charts prepared by the Admiralty in the 1800's. Some of them are skewed in relation to modern GPS coordinates, and plate tectonics has moved land up and down, otherwise, the sea is still in the same place

Jul 23, 2011 at 11:21 AM | Unregistered Commentergolf charley

"the sea is still in the same place"

And so are the ducks.

Jul 23, 2011 at 11:41 AM | Unregistered CommenterJames P

James P, I think the retreat of the white cliffs of Dover could be due to ducks tunneling under the chalk. The collapsing cliffs, fill the sea, and cause sea level rise. Any chance of a research grant?

Jul 23, 2011 at 12:30 PM | Unregistered Commentergolf charley

golf charley - so you mean it's all down to quacks in the cliff-face?

Jul 23, 2011 at 1:39 PM | Unregistered CommenterLC

LC, correct, why do you think shovellers were so named?

Jul 23, 2011 at 1:48 PM | Unregistered Commentergolf charley

Similarly, ducks can be blamed for decreasing arctic sea ice. Consider...

The eider duck, famous for its insulating "down" was hunted. The ducks would sit on the ice, near open water. Their body heat would locally warm the ice causing it to melt. As the ducks were hunted, their numbers declined, therefore less ice melt.

With cheaper and synthetic materials available for insulation, the hunting of eiders declined, the species recovered, and therefore more ice melted.

If in doubt, look to a ruddy duck as the cause, and remember you can't get "up" from a duck, only down, whereas climatology has everything up, and nothing down.

Jul 23, 2011 at 2:05 PM | Unregistered Commentergolf charley

golf charlie

"The collapsing cliffs, fill the sea, and cause sea level rise."

That is the duck filled hypothesis.

Jul 23, 2011 at 2:28 PM | Unregistered Commentersimpleseekeraftertruth

Church & White 2011 also has a graph of a simple average of tide gauges that updates the tide gauge average plot posted by Droz.

http://i.minus.com/idFxzI.jpg

(Bigger version of CW11 chart: http://oi51.tinypic.com/28tkoix.jpg)

Unlike 150+ year old single site thermometer records, tide gauge records are much more numerous and dispersed over a wider global area and they contain less decadal noise for the good reason that sea level has a lot of inertia attached to it along with a self-leveling nature. Nor are they subject to all manner of controversial adjustments over time. I simply do not see much variation from simple linearity in the vast majority of single site tide gauge records:

http://i.minus.com/idAw6Y.gif

Sea level is also something very simple for laypersons to comprehend, as is the story of how, rather shockingly, actual coastal sea level is not actually reported but instead a "corrected" virtual sea level is being incorrectly labelled as "sea level" by climatologists. You're in this debate way too deep if you don't comprehend the profundity of such a brazen hoax being presented with an attitude of high seriousness by Team members. That one graph, a simple average of tide gauges falsifies claims that ice melt is creating a surging sea and that falsifies claims that recent warming represents a massive trend change instead of a boring extenuation of the pre-CO2 emissions trend.

Arguing all year about the arcane mathematics of centennially chaotic temperature is dusty work when you already have the ideal experiment under wraps, with no statistics or politics or debate over poorly documented "corrections" being attached to it. That this simple graph doesn't clear this debate up tells me both sides have subconscious agendas and a desire to turn the weather in to a addictive armchair culture war. Finding this to be madness, a sense of deep disgust means I am now reducing my former extremely active online activism via news sites to a bare minimum. The tendency for skeptics to gather in echo chambers full of hundreds of daily posts while allowing activists from SkepticalScience and RealClimate to dominate the comments of online climate news stories also made me lose faith in skepticism as a grassroots movement worth participating in. I'm not flying solo any more, in the face of all indifference. I think skeptics have won the battle now anyway, not through online blogging but via the real world social effect of the few people who took the time to read the books that were finally produced, along with the slightly awkward support of skeptics by Fox News. What is needed next is a professional documentary or two. I could make one, since I do have the full equipment and expertise required and a trained voice, but it's too much to stomach, minus a $100K donor, and if I did make a new movie I'd honestly want it to be about something more interesting than the weather and less depressing than the madness of crowds.

"We are one good prime time documentary away from a mass exodus from the Act!-now!-or!-Fry! camp." - Joanne Nova, 23 July 2011

-=NikFromNYC=- Ph.D. in Carbon Chemistry (Columbia/Harvard)

Jul 23, 2011 at 2:44 PM | Unregistered CommenterNikFromNYC

Responding to NikFromNYC (Jul 23, 2011 at 2:44 PM)

Well said, Nik.

Jul 23, 2011 at 2:55 PM | Unregistered CommenterRoger Carr

NikFromNYC

Thanks for posting the link to Church & White. John Church has an extremely solid reputation. He's CLA of the sea level chapter in IPCC AR5 WG1.

Jul 23, 2011 at 3:06 PM | Unregistered CommenterRichard Betts

NikFromNYC

Its not about 'the science', never was. How should spectators respond when watching this theatre of the absurd? Lacking the required existential philosophy to participate fully, we can only contribute to the reviews. The real tragedy is that science is currently hijacked: by what, we can only surmise while waiting patiently for the show to eventually close.

Jul 23, 2011 at 3:15 PM | Unregistered Commentersimpleseekeraftertruth

Richard Betts, do you understand why I previously used the term "scaremongering" to describe some of the IPCC predictions, especially when the "scientists" prefer data from models over real observations?

Nik, you would struggle to get such a documentary broadcast in the UK

Jul 23, 2011 at 3:38 PM | Unregistered Commentergolf charley

PostPost a New Comment

Enter your information below to add a new comment.

My response is on my own website »
Author Email (optional):
Author URL (optional):
Post:
 
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>