New study finds sea levels rising only 7 in. per century – with no acceleration

Fig. 3.  Global sea level reconstruction since 1807, blue shadow represents 5 and 95% confidence intervalfrom CO2 Science: The authors write that “satellite altimetry measurements since 1993 have provided unique information about changes in global and regional mean sea levels,” suggesting a mean rate of rise of 3.2 mm/yr for global sea level over the period 1993-2012 (Boening et al., 2012; Cazenave et al., 2012), which “notably exceeds the estimate of 1.8 mm/yr sea level rise for the 20th century (Bindoff et al., 2007).”

So which rate is closest to the truth?

What was done

In a study designed to answer this question, Jevrejeva et al. (2014) say they “renew the global sea level [GSL] reconstruction by Jevrejeva et al. (2006), using monthly mean sea level data collected by the Permanent Service for Mean Sea Level (PSMSL) covering the observations from 1807 to 2010,” thereby improving the GSL reconstruction by increasing data coverage “by using many more stations, particularly in the polar regions, and recently processed historic data series from isolated island stations,” as well as by extending the end of the reconstruction from 2002 to 2009.

What was learned

Quoting the five researchers, “the new reconstruction suggests a linear trend of 1.9 ± 0.3 mm/yr [7.5 inches per century] during the 20th century” and “1.8 ± 0.5 mm/yr [7 inches per century] for the period 1970-2008.”

Fig. 3.  Global sea level reconstruction since 1807, blue shadow represents 5 and 95% confidence interval

Fig. 3.
Global sea level reconstruction since 1807, blue shadow represents 5 and 95% confidence interval

What it means

Although some regions have recently experienced much greater rates of sea level rise, such as the Arctic (3.6 mm/yr) and Antarctic (4.1 mm/yr), with the mid-1980s even exhibiting a rate of 5.3 mm/yr (Holgate, 2007), this newest analysis of the most comprehensive data set available suggests that there has been no dramatic increase – or any increase, for that matter – in the mean rate of global sea level rise due to the historical increase in the atmosphere’s CO2 concentration.[Therefore, there is no evidence of any human influence on sea levels]

The paper:

Trends and acceleration in global and regional sea levels since 1807. Global and Planetary Change 113: 11-22. Jevrejeva, S., Moore, J.C., Grinsted, A., Matthews, A.P. and Spada, G. 2014.

 

Abstract

We use 1277 tide gauge records since 1807 to provide an improved global sea level reconstruction and analyse the evolution of sea level trend and acceleration. In particular we use new data from the polar regions and remote islands to improve data coverage and extend the reconstruction to 2009. There is a good agreement between the rate of sea level rise (3.2 ± 0.4 mm·yr− 1) calculated from satellite altimetry and the rate of 3.1 ± 0.6 mm·yr− 1 from tide gauge based reconstruction for the overlapping time period (1993–2009). The new reconstruction suggests a linear trend of 1.9 ± 0.3 mm·yr− 1 during the 20th century, with 1.8 ± 0.5 mm·yr− 1 since 1970. Regional linear trends for 14 ocean basins since 1970 show the fastest sea level rise for the Antarctica (4.1 ± 0.8 mm·yr− 1) and Arctic (3.6 ± 0.3 mm·yr− 1). Choice of GIA correction is critical in the trends for the local and regional sea levels, introducing up to 8 mm·yr− 1 uncertainties for individual tide gauge records, up to 2 mm·yr− 1 for regional curves and up to 0.3–0.6 mm·yr− 1 in global sea level reconstruction. We calculate an acceleration of 0.02 ± 0.01 mm·yr− 2 in global sea level (1807–2009). In comparison the steric component of sea level shows an acceleration of 0.006 mm·yr− 2 and mass loss of glaciers accelerates at 0.003 mm·yr− 2 over 200 year long time series.

Full paper with figures is available here: http://www.sciencedirect.com/science/article/pii/S0921818113002750#f0015

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Gregory

Is there any way to tell in which areas the coast and sea bed dropped, accounting for these changes?

Steve Case

Gregory said at 6:09 pm
Is there any way to tell in which areas the coast and sea bed dropped, accounting for these changes?

Try this link:
http://www.psmsl.org/train_and_info/geo_signals/gia/peltier/

Latitude

Someone tell Gov Brown that he can leave his wading boots and life preserver at home
now. And scrap those plans for relocating LAX.

Reblogged this on Power To The People and commented:
@TomSteyer Buys @HarryReid http://freebeacon.com/blog/tom-steyer-buys-harry-reid/ All the money on earth can’t control #climate only God http://youtu.be/OP3bRZl8Xmk

Brad

This is going to raise h*ll with the alarmists… Bummer!

They never got the memo, “It’s worse than we thought. Or else.”

Steve Case

If you look up Colorado Univeristy’s Sea Level Research Group
http://sealevel.colorado.edu/
on the Internet WayBack Machine
https://archive.org/web/web.php
and look up the data from March 27 2004 (#version_2004_rel1.2) and do an analysis you will find that in 2004 the rate of sea level rise for 1992.928 – 2003.842 was 2.6 mm/yr.
Today (#version_2014_rel3) you will find that the rate of sea level rise for that same time series 1992.96 – 2003.819 is 3.5 mm/yr. A change of nearly a millimeter per year.
The historical data has been rewritten.

@Steve Case I noticed once that the rate seemed to increase between datasets, too. You can play with the URLs and go back at least 3 years, ex:
http://sealevel.colorado.edu/files/2014_rel3/sl_ns_global.txt
http://sealevel.colorado.edu/files/2011_rel1/sl_ns_global.txt
I plan to make a page that will let you analyze rates between different versions of their dataset over the same time period of data, I just haven’t gotten around to it yet.

From what I understand about things like the viscosity of water & gravity, the actual rate of sea-level rise can’t vary between locations on any long-term basis. Now, you do have things like isostatic rebound & subsidence, but those should tend to average out over a large enough number of tide gauges.
That is, unless the Earth itself is changing size.
*cue spooky music*

joshv

The paper does quote an acceleration, but for the period 1807-to 2009, which seems an odd period to quote as we’d be most interested in whether or not anthropogenic emissions had caused an acceleration in sea level rise. Comparing 1900-1950 and 1950-2009 would seem sufficient.

SIGINT EX

“So which rate is closest to the truth?”
NONE !
They are error ! and the papers are dog-s[..]t (a lower and more disgusting form of Bulls[..]t) !
[language. Mod]

Gamecock

Stark Dickflüssig says:
May 20, 2014 at 6:45 pm
That is, unless the Earth itself is changing size.
*cue spooky music*
===================
The underlying assumption is that the basin is a fixed size, which is preposterous. There are 15,000 volcanoes in the oceans. Tectonic plates are sliding all over the place. Rivers dump mountains of sediments into the seas. MSL is a concept, not a value.

Rud Istvan

Tide gauges without GPS for tectonic uplift/subsidence can say nothing on average. And GPS without local correction is not designed to be this accurate. And the rates found here disagree with the NASA sat altimetry data that everybody else uses. Just wrote for the next book about that.
All of which just proves the uncertainty monster is alive, well, large, and very scary.

Well I wouldn’t exactly say that “this newest analysis of the most comprehensive data set available suggests that there has been no dramatic increase – or any increase, for that matter – in the mean rate of global sea level rise due to the historical increase in the atmosphere’s CO2 concentration.”
The authors themselves say:
“We estimate an acceleration of 0.02 ± 0.01 mm·yr− 2 in global sea level by the conventional method, defining the acceleration as the second derivative of sea level with time (twice the quadratic coefficient), measured in mm·yr−2.”
“long term estimates of time variable sea level acceleration in 203 year global reconstruction are significantly positive, which supports our previous finding (Jevrejeva et al., 2008a), that despite strong low frequency variability (larger than 60 years) the rate of sea level rise is increasing with time.”
“The contribution from two components of sea level—melting of glaciers, and thermal expansion of the ocean, provide evidence of acceleration of 0.006 mm·yr− 2 and 0.003 mm·yr− 2 respectively (Fig. 16) since 1800. …At the same time steric sea level rise during the 20th century is determined mainly by increased anthropogenic forcing (Gregory et al., 2006).Greenland mass loss since 1840 shows an acceleration of 0.002 mm·yr− 2 (Box and Colgan, 2013). We cannot fully account for the 0.02 mm·yr−2 acceleration in the GSL12 reconstruction with these contributions alone. Accelerating mass loss from Antarctic and Greenland ice sheets since 1992 [Rignot et al., 2011] is an additional source of the recent sea level acceleration.”
They also point out that the choice of glacial isostatic adjustment datasets make a difference in the estimates and that better estimates are needed, especially in the Arctic and Antarctic.

bushbunny

I wish I could find the letter from BOM some years ago. They stated that sea levels would rise 177MM by 2050. It could have been 2100 for all I can remember. So where is the panic. Land does sometime sink, not much. Well done those people?

rogerknights

Figure 3 seems to show a leveling off in the past ten years or so (!).

Here’s the full text of the paper:
http://nora.nerc.ac.uk/504181/

Neville

Bush Bunny, a number of recent SL studies show a deceleration in SLR and the current rise is about 177mm or about 7 inches by 2100. ZIP difference to the 20th century.. And the 2014 Leclercque et al world glacier study shows that glacier retreat has slowed since 1950 or exactly the opposite to CAGW theory. IOW there’s ZIP evidence to show for CAGW at all.

Marcos

somewhere on the Colorado University Sea Level site I saw where it says that their numbers are not meant to be used to gauge the relation of sea level to land. I cant seem to find it now…

Michael P

I very much like that the seal level rise estimated in this study very closely matches the SF tide gage rate of 1.92 mm/yr since 1897. The NOAA data for SF also shows no discernible acceleration over time and the last 10+ years look look a decrease in rate (could be flat or dropping).

bushbunny

Neville yes I know, this letter, that I can’t find, but it wasn’t destroyed, is millimetres less than CM.
I seem to have found deaf ears with Tony Windsor stating this fact. He wiped me off years ago and I was once one of his staunch supporters and workers.

tommoriarty

I have been searching for a sea level rise at the end of the 20th century that would reconcile the 20th century’s average rise rate of 1.8mm/year with the satellite era average of about 3mm/year.
My findings so far have been published in a series of posts, with more to come. An index of these posts can be found here…
http://climatesanity.wordpress.com/the-search-for-acceleration/

Rick Cina

No Correlation Between Man-Made CO2 and Sea Level Rise Acceleration
According to the latest IPCC report (2013), sea levels rose at a rate 1.7 mm per year, or at a rate of 6.7 inches per century, between the years 1901 and 2010.
If Antarctica is melting faster because of man-made CO2, we should have necessarily seen a steep acceleration of sea level rise in the scientific record since about the 1950s to the present, as anthropogenic CO2 began it’s steep rise in the late 1940s, early 1950s, as shown on this epa.gov graph:
http://www.epa.gov/climatechange/images/ghgemissions/TrendsGlobalEmissions.png
But we don’t see that. Instead, peer-reviewed scientific papers tell us that, from the 1950s to the 2000s, sea level rise rates have slowed, or decelerated.
http://onlinelibrary.wiley.com/doi/10.1029/2006GL028492/abstract
The rate of sea level change was found to be larger in the early part of last century (2.03 mm/yr 1904–1953) in comparison with the latter part (1.45 mm/yr 1954–2003).
So, from 1904 to 1953 (50 years), CO2 ppm levels increased by ≈15 ppm, and sea levels rose by 2.03 mm/yr.
From 1953 to 2003 (50 years), CO2 ppm levels increased by ≈75 ppm, and sea level rose by 1.45 mm/yr.
Thus we can conclude that sea level rise decelerated by 40% during the same span of years that CO2 levels were increasing by 500% (15 ppm to 75 ppm), an inverse correlation.
This establishes a strong lack of correlation between CO2 amplification and sea level rise acceleration.
And if there is a lack of correlation between CO2 amplification and sea level rise acceleration, then it cannot be said that CO2 absolutely causes sea level rise acceleration. Further, it may be concluded that man-made CO2 does not cause accelerated rates of ocean heating, ice sheet and sea ice melt, or surface temperature heating.
Further peer-reviewed papers (abstract summary highlights) that have determined a deceleration trend since anthropogenic CO2 emissions began rising:
http://multi-science.metapress.com/content/q7j3kk0128292225/
For the last 40-50 years strong observational facts indicate virtually stable sea level conditions….contradicting all claims of a rapid global sea level rise, and instead suggests stable, to slightly falling, sea levels.
http://www.bioone.org/doi/abs/10.2112/JCOASTRES-D-10-00141.1
The analysis reveals a consistent trend of weak deceleration at each of these gauge sites throughout Australasia over the period from 1940 to 2000.
http://www.sciencedirect.com/science/article/pii/S0378383912000154
However, long term tide gauges, recording sea levels worldwide, as well as along the coastline of Australia, and within the bay of Sydney, do not show any sign of accelerating sea level rises at present time.
http://multi-science.metapress.com/content/k3xg21881l4k0161/
The paper shows that locally and globally measured data, collected over short and long time scales, prove that the claim of sea level sharply accelerating is false.
http://www.eike-klima-energie.eu/fileadmin/user_upload/jaeger/Moerner_Parker_ESAIJ2013.pdf
We revisit available tide gauge data along the coasts of Australia, and we are able to demonstrate that the rate may vary between 0.1 and 1.5 mm/year, and that there is an absence of acceleration over the last decades.
http://www.bioone.org/doi/abs/10.2112/JCOASTRES-D-10-00157.1
We analyze monthly-averaged records for 57 U.S. tide gauges in the Permanent Service for Mean Sea Level (PSMSL) data base that have lengths of 60–156 years…and 25 gauge records having data spanning from 1930 to 2010 are analyzed. [W]e obtain small average sea-level decelerations.
http://multi-science.metapress.com/content/575k5821r2w23t73
Morphological and stratigraphical observational facts in the Sundarban delta provide data for a novel sea level reconstruction of the area. This sea level documentation lacks traces of a global sea level rise. This implies totally new perspectives for the future of Bangladesh. No longer are there any reasons to fear an extensive sea level inundation in the near future.

Alan

All this stuff is hard to believe for a numbnuts like me. The seas are constantly moving up and down – waves and swells, and moving around with tides, the land is rising and falling in different places, and so presumably is the seabed, so for someone to measure the total to within millimetres boggles the imagination, if they could get it within the nearest couple of feet with any accuracy I would be surprised. (sorry for the long sentence)

Geoff Sherrington

Stark Dickflüssig says: May 20, 2014 at 6:45 pm
That is, unless the Earth itself is changing size.
…………….
In 2011 I emailed Xiaoiong Wu from JPL about this hypothesis and what had become known recently. The main exchange is below.
There are features beyond satellite measurement range, such as the precise size and shape of ocean floors, that are not yet known well enough to enter into the complete solution of the sea level rise equations. There are features like the East Pacific Bulge whose size is enough to change surface sea levels with little movement of its own, but I’m not sure that there are any estimates of how fast it is changing – if it is.
There are other known unknowns like the heat input from hydrothermal vents, again poorly characterised. In summary, so little is known abut the deeper 50% of the oceans and their floors that it is dangerous science to state very much at all about mechanisms affecting sea level change. That’s even without the unknown unknowns that can pop up when study gets more intensive.
However, Prof Lu’s response was about surface measurements. Sorry for the (condensed) length.
………………………
From: Wu, Xiaoping
Sent: Tuesday, September 27, 2011 10:16 AM
To: Geoff Sherrington
Subject: Re: Radius of the Earth
Hi, Dear Mr. Sherrington:
I know of nobody that has produced or performed an independent study like what we did. Previous attempts have been blurred by the presence of several geophysical processes that are known to exist, such as GIA and the fact that the geodetic network is not evenly or densely distributed.
On the question of G, you are right that we have not analyzed it. But several papers from Lunar laser ranging and Mars tracking data have clearly shown that G is a constant to the relative precision of 1X10^(-13)/year. This number is too small to be significant when compared with measurement precisions. So, G is really a constant. And these measurements are much less affected by any possible expansion of the solid Earth. Also, if you look at the scale difference between VLBI (very long baseline interferometry, which is not subject to the influence of the GM) and satellite laser ranging, there is no evidence of variability of G at the level of 0.16 mm/yr level.
I agree that the geological processes are very hard to quantify. That is why we approached the problem with a neutral point of view. But again, in the satellite analyses, GM has been considered constant. It is very hard to believe that the Earth’s mass is changing.
From: Geoff Sherrington
Date: Mon, 26 Sep 2011 16:41:17 -0700
To: Wu, Xiaoping
Subject: Re: Radius of the Earth
Dear Professor Wu,
Thank you for the paper and your reply. As noted, I have no firm position on whether the Earth is, or has been, expanding. However, I have had the experience of long personal discussions with the most advanced thinking available on the subject at the time, in the 1970- 1990s. (Prof Carey passed away in 2002).
(cuts)
The single question that I have is: Has anyone close to you performed a clean-sheet analysis of satellite positioning with a prime aim of looking for evidence? It is possible that your impressive refinement of orbital numbers has proceeded with no direct thought that G or g might be variable because you have not examined it as a prime possibility, but as an incidental effect. I doubt that this would happen at your level, but the circular logic problem can be devilish.
Geoff Sherrington.
From: Wu, Xiaoping
Sent: Tuesday, September 27, 2011 4:51 AM
To: Geoff Sherrington
Cc: Buis, Alan D.
Subject: Radius of the Earth
Dear Mr. Sherrington:
Thank you for your interest in our published research. For your information, I am attaching a pdf version of our paper. While I cannot speak for all JPL scientists, so far I have not heard any objections from them on this paper. But in science, it always takes time for people to scrutinize previous research and build consensus gradually.
We don’t have much assumptions in this particular paper on geology. However, most of the geodetic (satellite) data have been processed by several centers assuming the gravitational constant G is constant. That assumption is supported by overwhelming evidence from Mars tracking and lunar laser ranging. Currently, the estimated dG/dt is around 1X10^(-13) G per year. This number is smaller than the measurement uncertainties and not significantly different from 0.
As a scientist, I would not call our result in stone. It is the most recent confirmation that the solid Earth is not expanding beyond our measurement accuracy using a rather comprehensive method.
…………….
GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L13304, doi:10.1029/2011GL047450, 2011
Accuracy of the International Terrestrial Reference Frame origin and Earth expansion
X. Wu,1 X. Collilieux,2 Z. Altamimi,2 B. L. A. Vermeersen,3 R. S. Gross,1 and I. Fukumori1

Geoff Sherrington

Sorry, typo, should be Xiaoping not Xiaoiong.

NikFromNYC

NASA’s web site still presents a Climategate worthy deletion of tide gauge data in the ehole satellite era:
http://postimg.org/image/uszt3eei5/

I’ve read the paper. They don’t find there is no acceleration; as said in the abstract
” We calculate an acceleration of 0.02 ± 0.01 mm·yr- 2 in global sea level (1807–2009).”
Furthermore
“3.1 ± 0.6 mm·yr- 1 from tide gauge based reconstruction for the overlapping time period (1993–2009)”
What they do find is that acceleration varies over time. It was negative from about 1950 to 1975, and positive from about 1980 to 1995 (Fig 15). Since then it is patchy, but of course the periods available to fit a quadratic are smaller, with noisy results.

phlogiston

One can see from fig 3 why 1850 is such a convenient date to begin climate science, for the warmists.

Skiphil

oh, c’mon! Everyone knows that sea level rise is wildly out of control….. only cranks would deny it!
p.s. Did you know that the whole UNFCCC => IPCC process was launched, via activist scientists at WMO and UNEP workshops, claiming that SLR should now be somewhere between 5.5 cm and 24 cm per DECADE?? (closer to 24 cm based upon humanity’s rather tepid response to demands to slash emissions etc.).
yup, that is what they were fear mongering about when lobbying to create the IPCC:
http://judithcurry.com/2014/05/20/climate-scientists-joining-advocacy-groups/#comment-562577

Peter Miller

Is this another example of the observations say this and the models say that, so the observations are wrong?
I am obviously speaking from the alarmist point of view.

Skiphil

oh, the report from which that figure with 1987 projections of SLR is linked here:
http://judithcurry.com/2014/05/20/climate-scientists-joining-advocacy-groups/#comment-562125
based upon humanity’s failure to do much under the instruction of our betters, we ought to be approaching the higher rate of 24 cm per decade of SLR anytime now….. that is what the IPCC was created to forestall !!

Skiphil

btw, speaking of activist scientists, Peter Gleick is listed as one of the 1987 workshop participants!
(Appendix I, p.44)
no wonder he goes nuts over this stuff, it really is his life’s work and he takes all dissent or opposition quite …. personally …. and seriously.

tty

Steve Case says:
Try this link:
http://www.psmsl.org/train_and_info/geo_signals/gia/peltier/
I would not recommend using the Peltier GIA. The ICE-5G model is known to be grossly inaccurate, particularly in Antarctica.

tty

Regional linear trends for 14 ocean basins since 1970 show the fastest sea level rise for the Antarctica (4.1 ± 0.8 mm·yr− 1) and Arctic (3.6 ± 0.3 mm·yr− 1).
And this by the way is pretty conclusive proof that there has been no major decrease in the amount of ice on Greenland or Antarctica. When an ice-cap is losing mass sea level will go down in the vicinity, both because land will be raising because of the decreased load of ice, and because the gravitational attraction of the ice-mass pulls up the sea-level around the icecap. The latter effect is surprisingly strong and means e. g. that even a complete melting of the Greenland ice-cap would have little effect on the relative sea-level in northern Europe.

John Peter

“Nick Stokes says:
May 20, 2014 at 10:53 pm
I’ve read the paper. They don’t find there is no acceleration; as said in the abstract
” We calculate an acceleration of 0.02 ± 0.01 mm·yr- 2 in global sea level (1807–2009).”
As I understand this, on average sea levels have accelerated 0.02+/- 0.01mm year over 202 years or 4.04mm in total added to global sea levels. I for one is not losing any sleep over that. Bearing in mind the uncertainty over measurements even today this figure is probably no better than a guess. Like in all other measurements underpinning CAGW there is no dangerous acceleration to be found anywhere.

John Peter says: May 21, 2014 at 12:05 am
“As I understand this, on average sea levels have accelerated 0.02+/- 0.01mm year over 202 years or 4.04mm in total added to global sea levels.”

No, it is .02 mm/yr/yr, A rise of 4.0 mm/yr in the rate.

Nick Stokes says:
May 20, 2014 at 10:53 pm
I’ve read the paper. They don’t find there is no acceleration; as said in the abstract
” We calculate an acceleration of 0.02 ± 0.01 mm·yr- 2 in global sea level (1807–2009).”

Yes, but 1807 is not a very interesting date. There is no acceleration (by “eye-meter”) since 1860.

Greg

joshua says:
@Steve Case I noticed once that the rate seemed to increase between datasets, too. You can play with the URLs and go back at least 3 years, ex:
http://sealevel.colorado.edu/files/2014_rel3/sl_ns_global.txt
http://sealevel.colorado.edu/files/2011_rel1/sl_ns_global.txt
===
Good man! Any idea if we can access with/without inv. barometer frig as well?

Greg

daveburton says:
Here’s the full text of the paper: http://nora.nerc.ac.uk/504181/
Nice work Dave. I had a quick hunt and did not find it. I should have looked here first. WUWT is more use than Google!

Greg

Anthony, how about getting this link added to the article? http://nora.nerc.ac.uk/504181/

sibeen

Nick Stokes says:
May 21, 2014 at 12:37 am
No, it is .02 mm/yr/yr, A rise of 4.0 mm/yr in the rate.

Nick, how can that match up with the paper’s figure of a current rate of rise of 1.9 mm/yr?

phlogiston

Almost uniform sea level rise since 1850 with recent slight deceleration – as RGB recently put it, “comes dangerously close to falsifying the whole CAGW hypothesis”.
They can’t claim accelerating ice loss and missing heat hiding in the sea with ZERO signal from sea level rise.

sibeen says: May 21, 2014 at 1:29 am
“Nick, how can that match up with the paper’s figure of a current rate of rise of 1.9 mm/yr?”

No the paper doesn’t say that. It says the rise 1993-2009 is 3.1 mm/yr.
They get acceleration by fitting a quadratic. There are examples in their Fig 16. The initial slope is negative, and the final slope exceeds 3.1 mm/yr.

Greg Goodman

Jevrejava is by no means a GW sceptic to read some of her comments, but I do think that she is a serious scientist. I have been waiting years for her to update here 2006 paper which had a data cut-off in 2002.
This is a very detailed paper and will take some time to digest.
One thing I do find rather questionable is the “acceleration” findings. Looking at their figure 16 where they fit quadratics to data from two other papers, it is clear that the data has some periodic content and that the quadratic is fitted over a peak-tough-peak section
this will give a positive “acceleration” that is probably not representative of what is really happening.
It’s just another version of the warming cosine fallacy:
http://climategrog.wordpress.com/?attachment_id=209
That is rather disappointing.
The regional breakdown is very interesting and requires more inspection. NE Pacific and NE Atlantic are nearly flat and NW or each ocean are amount the steepest gains.
Is this really steric components leading to sea levels of less dense water piling up on one side of each basin or a problem with the GAIA [sic] adjustments
Also lesser increase in southern Atlantic and Pacific. Large water mass , less warming?
Certainly plenty to chew on here. Looks like the most thorough and detailed study of sea levels to date. Though surely not with some faults, it looks very informative.

Greg Goodman

See fig 11 showing that some of the “acceleration” is due to GAIA adjustments. ( In theory glacial rebound can not be accelerating. This means there is a problem somewhere).
It’s flat before 1850, goes to an increase of about 0.5 mm/yr during 1850-2000.
That’s a fairly sharp acceleration around 1880. Seems fairly const rate of change since 1900. Perhaps someone ought to fit a quadratic to that too.
If I take the midpoint if each period 1825 and 1925 that’s 0.5mm/yr/century, or 0.005 mm/yr^2
Compare that to the figures they derive from fig 16 : 0.006 and 0.003 mm/yr^2
It should be remembered that GAIA adjusted sea rise may help calculations but are irrelevant to what matters to populations in coastal areas which most of the scare-mongering and wild claims are based on. No-one gets flooded out by an “corrected” sea level , it’s wet kind of sea level that matters.

Greg Goodman

” Fitting a second order polynomial to the GSL12 for the period
1880–2009 gives an acceleration of 0.001 mm·yr^2 , which is much
smaller than the 0.009 mm·yr−2 reported by Church and White”
“Using 10,000 Monte Carlo simulations we estimate a 5–95% confidence interval of 0.01–
0.04 mm·yr^2 for the 0.02 mm·yr^2 acceleration.”
I think that’s what is often referred to as not “statistically significant”. They don’t give any error estimation for the 1880-2009 “acceleration” of 0.001 mm·yr^2 but it is clearly it is not significant.
They seem to make a bit too much of this “finding” but at least they are thorough and above board. The data is presented with all the warts for anyone who wants to see how they got there.

Greg,
“In theory glacial rebound can not be accelerating. This means there is a problem somewher”
In theory it isn’t. The left side of Fig 10 shows that. The right side shows how that is affected by data gaps (I’m not sure why). I think Fig 11 reflects that.

Greg Goodman

To put this another way 0.001 mm·yr^2 = 10 mm/century/century
ie in 100 years time sea level (may be) rising 10 mm / century faster than it is now.
I don’t think even Bangladesh need to worry about the “acceleration”.
Indeed if we look at their figure 7 the tide gauge record shows NO change in sea level since about 2003. This seems to reflect the temperature “hiatus”. This is in contrast to the politically correct satellite record.