Sea Level Rise Accelerating? Not.

Guest Post by Willis Eschenbach (NOTE UPDATE AT END)

There’s a recent and good post here at WUWT by Larry Kummer about sea level rise. However, I disagree with a couple of his comments, viz:

(b) There are some tentative signs that the rate of increase is already accelerating, rather than just fluctuating. But the data is noisy (lots of natural variation) and the (tentative) acceleration is small — near the resolving power of these systems (hence the significance of the frequent revisions).

(c) Graph E in paper (5) is the key. As the world continues to warm, the rate of sea level rise will accelerate (probably slowly). 

This question all revolves around whether the rate of sea level rise is relatively steady, or whether it is accelerating … so how do we tell the difference?

Well, how I do it is to fit two models to the data and see which one works better. The first is a straight-line model (a linear fit), and the other is an accelerating model (a “quadratic” fit). Figure 1 shows an example of some pseudo-tidal data which in fact has an accelerating rate of sea level rise. I’ve created it by simply adding an accelerating trend to an actual tidal record.

tide pseudodata accelerating

Figure 1. Artificial pseudodata of a tidal gauge recording an accelerating rate of sea level rise.

As you can see, the blue line showing an accelerating (quadratic) fit matches the data much better than the linear fit (red). How much better? Well, that’s measured by something called “R-squared” (R^2). This is a value between zero and one which measures how well the given line explains the dataset.

The R^2 for the blue line (0.88 ± 0.02) is much larger than the R^2 for the red line (0.77 ± 0.02). And since the difference between the two values is greater than the sum of the standard errors of the two values, we can say that the difference between them is statistically significant. In other words, in the Figure 1 case, we can say that there is a statistically significant acceleration in the dataset.

So that is what I planned to look at—whether the difference between the R^2 for the linear and the quadratic fits is greater than the sum of their standard errors.

With that as prologue, let me discuss my methods. I took the full tidal dataset from the Permanent Service for Mean Sea Level. It has 1,505 tide station records in it. However, as with most historical datasets, there are lots of gaps and stations with short or spotty records.

So I had to use a subset of the data. Because the long lunar tidal cycle is just over fifty years, you need at least that much data to get a serious estimate of the rate of sea level rise. And we are interested in any recent acceleration. So I limited my analysis to tidal stations with data starting before 1950 and ending after 2015. This cuts the list down to 171 stations which cover the period of interest.

However, some of these are missing a lot of data, some with over half of the data gone. I wanted enough data to have faith in the analysis, so I further limited the dataset to those stations having 95% or more of the data during 1950-2015. This further reduced the number of tidal stations to 63. Figure 2 shows a sample of 10 of these.

typical tide gauge records

Figure 2. Typical records which fit the criteria of the ex-ante data selection process (95% data coverage from 1950-2017)

Now, my Mark 1 Eyeball says that if there is acceleration there, it is minor … but let’s look at the numbers. Here is a scatterplot of the R^2 values of the linear fit versus the R^2 values of the quadratic fit:

comparison fits linear quadratic

Figure 3. Scatterplot, R^2 of the linear fit vs. the R^2 of the accelerating (quadratic) fit. Dots above the diagonal line are stations where the R^2 of the accelerating (quadratic) fit is larger than the R^2 of the linear fit.

As you can see, in almost all cases the gain in the goodness of fit when we go from linear to quadratic fits is trivially small, invisible at this scale. And when I examined the gain in R^2 versus the standard errors for each of the 63 stations, in every single case the accelerating fit was NOT statistically better than the linear fit.

In other words, not one of these datasets shows statistically significant acceleration.

And that is why at the top I said that I disagree with the following statement from the other post, viz:

There are some tentative signs that the rate of increase is already accelerating …

Simply not true. Figure 3 shows clearly that the tidal gauges contain no such “tentative signs”. NOT ONE of these 63 full tidal datasets shows statistically significant acceleration, and more to the point, most of them show only a trivially small difference between acceleration and a simple linear fit.

The other statement I disagreed with was:

As the world continues to warm, the rate of sea level rise will accelerate (probably slowly) …

Look, this is just the same nonsense that the alarmists have been peddling for the last thirty years, that in the future the sea level rise will accelerate, that New York will be underwater, and the like … but it has been thirty years since the first bogus prognostication was made, and there is still no evidence that the sea level rise is accelerating.

Look, I’m all in favor of taking care about the future … however, call me crazy but I need EVIDENCE before I start hyperventilating about Miami sinking into the ocean.


5 PM, the dreaded global warming has cooled down now. Me, I’m going to post this and then go outside to lay some pavers in the new level space I just made with my own sweat. Plus a rented backhoe. I could have hired someone, but why should illegal immigrants have all the fun? I like living in the hills … but this is the first and only flat spot on my land, so I’m making it nice.

the patio

What a universe!

Best to everyone,

w.

PS—The Usual: When you comment, please QUOTE THE EXACT WORDS YOU ARE DISCUSSING, so that we can all be clear about your precise subject.

DATA—I’ve put the 63-station data here, as a CSV file so that anyone can use it in Excel or any other program.

[UPDATE] Over at Tamino’s website, where since about 2009 I’m barred from commenting because I was asking inconvenient questions, he points out that there is a simpler and more accurate method for finding out if a dataset contains acceleration. This is to see if the squared term in the quadratic equation is statistically significant after correction for autocorrelation, duh … he is correct.

My thanks to him for pointing this out, although I do have to deduct points for his repeated ad hominem attacks on me in his post … haters gonna hate, I guess.

Using his method I identified seven of the sixty-three stations as having statistically significant acceleration and three stations with statistically significant deceleration. However, the average value of their acceleration is 0.015 ± 0.012 mm/yr2 … which is not statistically different from zero. Here are the stations and their accelerations:

       VLISSINGEN         BALTIMORE            SMOGEN          KEY WEST         KETCHIKAN

           0.0605            0.0542            0.0676            0.0477           -0.0543

WEST-TERSCHELLING        SANDY HOOK            JUNEAU             SITKA         KWAJALEIN

           0.0979            0.0510           -0.1052           -0.0573            0.1258

I note that one station he says has significant acceleration doesn’t appear in this list (Boston). I find that the p-value of the acceleration term for Boston is 0.08, not significant. I suspect the difference is in how we account for autocorrelation. I use the method of Koutsoyiannis, detailed here. I don’t know how Tamino does it.

I would also note that the average acceleration of the entire 63-station dataset is 0.014 ± 0.008, still not statistically significant. And if this turns out to be the long-term acceleration, currently the rate of rise is on the order of a couple of mm/yr, or 166 mm (about 7 inches) by the year 2100. IF this increases at 0.014 mm/yr2, this will make a difference of 48 mm (under two inches) this century.

Curiously, in the previous fifty-year period 1900-1950 there are only three sites with significant acceleration out of 38 datasets covering the period, and none are in the first list:

NEW YORK (THE BATTERY)              HARLINGEN                SEATTLE

                0.0976                -0.1182                 0.0959

Whatever any future sea level acceleration turns out to be, it is very unlikely to put the Statue of Liberty underwater anytime soon …

Man, I love writing for the web. All my errors get exposed in the burning glare of the public marketplace of ideas, I get to learn new things, what’s not to like?

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Heath
July 20, 2017 5:59 pm

Your more likely to see the water control systems break down and South Florida return to Everglades before the sea swamps Miami

Another Ian
July 20, 2017 6:04 pm

Willis
Typo?
data starting before 1950 and ending after 1915.

Reply to  Willis Eschenbach
July 21, 2017 8:04 am

The Jevrejeva data derived from tide gauges was discussed in a post by David Middleton a few days ago. That data goes back to 1820 and also reports an acceleration.
I used a 48 month gaussian filter on the rate of change of mean sea level to remove the short term fuzz.comment image
As Jevrejeva 2014 reports there is an acceleration but it happened BEFORE 1900 and thus had nothing to do with human CO2 etc. In fact, it was almost a step change from decreaseing sea level ( negative change ) to rising sea levels which occurred around 1860.
Jevrejeva 2014 confirms that there is NO acceleration in the 20th century.

Reply to  Willis Eschenbach
July 21, 2017 8:10 am

So looking at that data we see that if you blinker the analysis suitably ( eg. post 1950 because you are looking human attributable effect, and don’t want to to find anything contrary to that idea, as IPCC does with global temps ) you will find evidence of acceleration.
However, it is abundantly clear that this is no more that the preceding wiggles which can only be attributed to natural causes.
There was a notable ( natural ) acceleration around 1860 but the last 150y has basically being hovering around the same steady rate of rise, oblivious to the alleged effects of AGW, GHE etc.

Reply to  Willis Eschenbach
July 21, 2017 8:14 am

If we chose to study 1920 – 1950 we can find a deceleration which is probably a little stronger than the later acceleration. There are no grounds for suggesting the later variability is due to human causes.
Since attempts to explain the lack of catastrophic global warming over the last two decades seems to centre on the idea that all the heat is hiding in the oceans, it is BIG problem that the oceans don’t seem to have noticed yet.

Steve Case
July 20, 2017 6:06 pm

This is sea level week (-:
There’s been a flurry of “sea level is accelerating” stories in the “Popular Press” in the last week or so, most cite that the rate of sea level rise has doubled or more since 1970 or thereabouts. Prior history seems to be ignored. So what do long running tide gauges say about the rate for the last several decades?
http://oi66.tinypic.com/1zv7rwg.jpg
The median value shows a tiny increase compared to 1950.

Joe Born
Reply to  Willis Eschenbach
July 20, 2017 7:52 pm

Good job, Mr. Eschenbach. But Steve Case got to the heart of the matter. Yes, you can find acceleration if you take the right interval and the right data set.
But, as Mr. Case recognized, you could have found that much acceleration half a century ago, too–and it was followed by deceleration. In other words, the question isn’t whether there’s been some acceleration. Of course there has been, if you pick the right interval and time scale. The question is whether that acceleration gives us much insight into the future, which is what we’re really concerned with. The answer is no.
‘Twas ever thus. As Mark Twain said over a hundred years ago:

In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oölitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.

jclarke341
Reply to  Willis Eschenbach
July 21, 2017 5:15 am

Love the Twain quote, Joe. Thanks! The ‘money’ line: “One gets such wholesale returns of conjecture out of such a trifling investment of fact.” That describes man-made climate change science to a ‘T’.

talldave2
Reply to  Steve Case
July 21, 2017 7:10 am

Despite the obvious flaws, probably still a better rough temperature proxy there than GISS models, too.

Editor
July 20, 2017 6:09 pm

What a quandary! Do I side with Willis or Larry?
I’m gonna lean towards not accelerating…comment image
And, it wouldn’t matter if it was…comment imagecomment image

Dave
Reply to  David Middleton
July 21, 2017 6:10 am

David these are purportedly from a Liverpool University study, please could you show us the graph from the original paper, as you did in 2008 , The abstract of this 2014 paper stated that the sea level acceleration was calculated to be small 0.02 mm /yr^2.
Also the dip at 1860 does not appear in the Liverpool , Stockholm or Amsterdam data, nor in the data from Jevrejeva in 2008
Your dip states that the sea behaved differently in northern Europe to the rest of the data.Yet you in a post earlier lauded Liverpool as one of the best tidal study group in the world.
Ref SJevrejeva st al Global and Planetary Change vol113, p11 (2014)

Reply to  Dave
July 21, 2017 6:52 am

“Liverpool” has nothing to do with anything. You keep asking why individual tide gauge stations don’t look like a eustatic sea level reconstruction. That’s like asking why a 2×4 doesn’t look like a house.
Tide gauges reflect eustatic (water moving up and down) and isostatic (land moving up and down) sea level changes.
A reconstruction of global eustatic sea level is an average of many tide gauges after the isostatic component has been removed.
The tide gauge at Amsterdam shows no sea level trend before 1823, a step-shift up, and then no trend until 1875. Stockholm exhibits a steady 4 mm/yr drop in sea level.comment image
Jevrejeva 2008 looks like this…
http://www.psmsl.org/products/reconstructions/figure1.gif

The “virtual station” GSL calculated from 1023 tide gauge records [Jevrejeva et al., 2006], optimally solves the sampling problem of station locations. Detailed descriptions of these time series are available from the data page at the PSMSL. All data sets were corrected for local datum changes and glacial isostatic adjustment (GIA) of the solid Earth [Peltier, 2001]. The reconstruction preserves volcanic signatures [Grinsted et al., 2007] and also has published standard errors [Jevrejeva et al., 2006].
Authors extend the record backwards from 1850 using three of the longest (though discontinuous) tide gauge records available: Amsterdam, since 1700 [ Van Veen, 1945], Liverpool, since 1768 [Woodworth, 1999] and Stockholm, since 1774 [Ekman, 1988]. We remove the linear part of each record, which contains the land movement component, by comparing each time series with the existing GSL for the period of overlap.

http://www.psmsl.org/products/reconstructions/jevrejevaetal2008.php
Jevrejeva 2014 looks like this…comment image

Authors have used 1277 tide gauge records of relative sea level (RSL) monthly mean time series from the Permanent Service for Mean Sea Level (PSMSL) database [Holgate et al, 2013]. Detailed descriptions of the RSL time series are available from the data page at the PSMSL. No inverted barometer correction was applied. RSL data sets were corrected for local datum changes and glacial isostatic adjustment (GIA) of the solid Earth [Peltier, 2004].

http://www.psmsl.org/products/reconstructions/jevrejevaetal2014.php
It’s not *MY* dip. The “dip” is in the reconstruction…

There is a noticeable difference between reconstructions for the early period of observations around 1850 (Fig. 6, panel b) due to additional historical time series becoming available for use in the present study.

http://nora.nerc.ac.uk/504181/1/1-s2.0-S0921818113002750-main.pdf

Reply to  Dave
July 21, 2017 7:22 am

Here’s an animated comparison of Jevrejeva 08 and 14…comment image
The pre-1850 error range is large in both reconstructions. The error ranges generally overlap. The difference appears to be in the data selection pre-1850.

Steve Case
July 20, 2017 6:19 pm

If you go to this PSMSL page
http://www.psmsl.org/products/reconstructions/gslGPChange2014.txt
and plot out column “D” from 1861.29 the trend is flat, no acceleration.

Steve Case
Reply to  Steve Case
July 20, 2017 6:39 pm

Quick & dirty – Here’s what that looks like:
http://oi66.tinypic.com/iz1g2g.jpg

Reply to  Steve Case
July 20, 2017 6:48 pm

Yep.

John Coghlan
July 20, 2017 6:21 pm

Spot on Willis, but that’s not surprising since you usually are !!

ЯΞ√ΩLUT↑☼N
July 20, 2017 6:24 pm

Sea levels rose sharply some 12,000 years ago as we came out of the last ice age began using trendy SUV’s. It seems the only way to solve this catastrophic dilemma is to have millions of wind-powered snow making machines create another mile-high glacier over Canada (sorry).
Gotta keep the SUV’s though.. Station wagon’s are just so yesterday.

Cold in Wisconsin
July 20, 2017 6:27 pm

Since the manipulate the land based temperature records, why have they not started manipulating and adjusting the tide gauge records? With terrestrial temperature readings they “adjust” the station data but leave the satellites alone. With sea level measurements they now adjust the satellite measurements but leave the tide gauges alone. It won’t be long before they control all of the data and there will be no sanity check.

ЯΞ√ΩLUT↑☼N
Reply to  Cold in Wisconsin
July 20, 2017 6:40 pm

The ever upward adjustment of their data is in correlation to their bank accounts.

Voltron
July 20, 2017 6:35 pm

Having done quite a bit of stats in my time as a undergrad psych, I found two things, guilt is a strong motivator for behaviour change (and I sat through a number of lectures about how guilt could be used to get people to be ‘more green’) and that stats can be massaged to produce a result. Even if you don’t get a statistically significant result, you can always throw in the line that the data is “trending towards significance” and that’ll probably be good enough for people with an agenda to push. Nice to see some numbers here reflecting some cold math and not bias

Steve Case
Reply to  Willis Eschenbach
July 21, 2017 3:56 am

A further note. Forrest, I’m sorry, but an exponential function will not work at all in this application. Inappropriate choice. Think about it. If you can’t say why it won’t work, just ask.

Not everyone thinks so (-:
Paleoclimate Implications for Human-Made Climate Change
James E. Hansen and Makiko Sato

http://www.mahurangi.org.nz/wp/wp-content/uploads/2014/12/Figure-7-v2.jpg
Fig. 7. Five-meter sea level change in 21st century under assumption of linear change (Alley, 2010) and exponential change (Hansen, 2007), the latter with a 10-year doubling time.

Larry Hamlin
July 20, 2017 6:40 pm

Excellent post.
Thanks Willis.

ferdberple
July 20, 2017 6:41 pm

So Willis, you did some sailing. Probably using charts surveyed well over 100 years ago. More likely 200+. So in all that time did you ever see a chart datum corrected for sea level rise? Did you ever see any chart that was obviously wrong due to what you now recognize as sea level rise?

ferdberple
Reply to  Willis Eschenbach
July 20, 2017 7:16 pm

Hi Willis, fathom charts were drawn to the nearest foot for water less than one fathom. It has been my experience they were drawn to a level of accuracy few could duplicate today. Bligh’s charts of Tonga are astounding accurate, drawn in the 1773? While aboard the Bounty.
But what really interested me was drying and awash rocks as we sailed, which are of course extremely dangerous so you pay attention to any errors. The problem is there were none. which suggests sea level rise is a non event.

Reply to  ferdberple
July 20, 2017 6:54 pm

I’ve worked one particular field in the Gulf of Mexico for 4 different companies since 1988. Neither the water depth of the platform nor any of the wells drilled from it has changed. Of course, we only measure to the nearest foot… So Gorebal Warming-related sea level rise is below our resolution… 😉

ferdberple
Reply to  ferdberple
July 20, 2017 7:46 pm

I would expect sailors 200+ years ago could tell you within a foot MLLW. Anything your life depends on you tend to get very good at (those that don’t die). And this applied in spades for those sailors that charted the earth. I expect every sailor appreciates what it is like sailing uncharted waters. The level of skill involved. Even back 15 years, after 20 afloat I routinely predict the change in weather better than our local weather service, without even thinking about it.

Tsk Tsk
Reply to  Willis Eschenbach
July 20, 2017 7:08 pm

I’ll take adjusted r-squared for $1000, Alex.
“With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.” – John von Neumann
“String Theory is just power fitting the Universe.” – Tsk Tsk

Javert Chip
Reply to  Willis Eschenbach
July 20, 2017 8:26 pm

Tsk Tsk
+6.022 X 10^^23 & Supersymmetry died at CERN

nobodysknowledge
Reply to  Willis Eschenbach
July 21, 2017 2:12 am

I have thought that an exponential function is the best choice for acceleration. It`s like putting money in the bank and let it grow (with constant interest). Most scientists talk about exponential growth when it comes to acceleration. So I cannot see why it will not work.

Ray in SC
Reply to  Willis Eschenbach
July 21, 2017 5:24 am

Forrest,
Willis said; “If you think an exponential is a better function to use than a quadratic, how about you ACTUALLY USE IT ON THE DATA THAT I GAVE YOU and post your results here. That way we can see if you actually have a point.”
The data is available so show us how an exponential, a cubic, or whatever function you choose has a better fit. Otherwise, what is your point?

ferdberple
July 20, 2017 6:46 pm

So the world authority on sea level rise is in Colorado, about as far from the sea as any place on earth. Pretty much describes the results they generate.

AJB
Reply to  ferdberple
July 21, 2017 6:41 pm

Hmm, have you read this per chance …
“Is the detection of accelerated sea level rise imminent?” doi:10.1038/srep31245
https://www.nature.com/articles/srep31245

AJB
Reply to  ferdberple
July 21, 2017 7:48 pm

Since using their own numbers the mean acceleration is currently negative (and utterly meaningless anyway given the noise) we can presumably safely assume the answer is emphatically no.
I guess we’ll just have to rely on rulers and numerological barking dogs for an opinionated coin flip having first deducted the odd volcano, etc. here and there by whatever dubious means. Meanwhile the world keeps on turning and churning, just as it did yesterday.

afonzarelli
July 20, 2017 6:53 pm

http://www.realclimate.org/images//sea_level_rise_vs_temperature.png
The rate of sea level rise is tied to the surface temperature above an equilibrium state temperature. Seeing how global temps have paused, the rate of sea level rise has also paused. The future largely depends on the success of AGW theory. (don’t bet the beach front house on that)…

Geoff Sherrington
Reply to  afonzarelli
July 20, 2017 8:06 pm

So what is the quantitative rise or fall in sea level for a temperature change of 1 deg C?
For the 3 cases when that 1 deg C is from satellite microwave, from surface air temperature and from sea temperature.
Why can there not be a simple equation linking rise/ fall to temperature somewhere?
Why cannot the oceans emulate a liquid in glass thermometer?
Geoff

afonzarelli
Reply to  Geoff Sherrington
July 20, 2017 9:18 pm

comment image
Hi, Willis, graphs like rahmstorf are dime a dozen. Here’s another one albeit much more crude. (rahmstorf is highly smoothed to get what they got) Remember, these are derivative plots, the RATE of sea level rise, not the accumulation there of. i can at least see the rate of accumulation speeding up and slowing down and then up again in your graph. Is that particular data set available in a derivative plot?
Let me know, if possible, where you think rahmstorf (and the rest) might be going wrong here. Thanx…

GregK
Reply to  Geoff Sherrington
July 21, 2017 1:44 am

Geoff,
That’s a bit difficult to work out.
The oceans are a bit more complicated than liquid in a thermometer.
Varying depths, currents, bits of land that poke out into them, how long it takes to warm up…
First how much ocean are you warming by 1 degree C ..a column of 1 metre, 10metres, 100 metres, 1000 metres, 6000 metres?
It’d take a while to warm up 6000 metres of water by 1 degree C
Here’s a go at it…page 6 is the immediately relevant bit but includes lots of assumptions
[The author admits it’s a very simplistic approach but it gives you an idea of what’s involved]
The calculations suggest a 17cm rise if temperature increases 3 degrees.
http://cosmo.nyu.edu/Shoshana_Sommer.pdf

Geoff Sherrington
Reply to  Geoff Sherrington
July 21, 2017 5:31 am

Greg K
Thanks for he references, though I note I did a Google months ago and found some of same.
Fundamentally, when a photon enters the sea it will change the energy of the sea almost instaneously. In this state, it expand or contracts. If you select a vertical column of water from a larger region of systematic change, that should emulate a LIG thermometer. Mixing, stratification, density, salinity should not really influence this emulation. Therefore, it should be possible to derive said equation linking sea level and temperature changes.
I would have thought this a fundamental equation for oceanography, but despite several searches I have not been able to find that equation. Most papers go straight to Their change with time. I want time out of the equation like it is when you stick a thermometer under your tongue. You do not have to wait hours to your tongue to equilibrate.
The oceans do not have temporary energy storage buffers where the effect of a photon can be stored, hidden, until the ocean works out what to dobwith it.
BTW, I have similar lack of success when I try to find out if oceans cool at night, how fast, and by what mechanism: and the reverse case in daytime.
Geoff

Reply to  Geoff Sherrington
July 21, 2017 9:08 am

The red curve in Fonz’s graph from Rahmstorf 2007 is based on Church & White (2006), a PSMSL reconstruction… I don’t think any two PSMSL reconstructions have looked alike. Jeverejeva et at, 2014 does indicate local variations in the rate of SLR which could be due to fluctuations in the rate of warming…comment image
The long-term rate since ~1860 has been about 1.9 mm/yr. There have been alternating 20-40 year sequences of ~3 mm/yr and ~1 mm/yr.

Gloateus
Reply to  Geoff Sherrington
July 21, 2017 11:45 am

Geoff Sherrington July 20, 2017 at 8:06 pm
If (a big If) MSL has in fact risen 350 mm since 1850, and if (an even bigger If) average global temperature has indeed increased 1.0 degree C since then, then the answer to your question should be about 350 mm.
However the effect is probably not a direct linear relationship, so who knows? Sea level was higher in the past when it was warmer during the Holocene and previous interglacials, with the continents in about their present arrangement, and if prior epochs, periods, eras and eons, when the continents were arranged differently, so there is at least a general relationship.

Gloateus
Reply to  Geoff Sherrington
July 21, 2017 11:47 am

The high sea level of the Cretaceous however owed to thermal expansion and ridge growth due to rapid sea floor spreading, as well as to the hot and equable climate of that period.

afonzarelli
Reply to  Geoff Sherrington
July 21, 2017 4:52 pm

comment image

afonzarelli
Reply to  Geoff Sherrington
July 21, 2017 5:01 pm

Sea level rise from the depths of the last glacial until the present interglacial is about 130 meters(!) Being generous, if we divide that number by 5C (thought to be the maximum global temperature difference from the last glacial to this interglacial) we get about 25 meters per degree celsius. That means it takes a long time for everything to equilibrate with a change in surface temps…

Menicholas
Reply to  Geoff Sherrington
July 21, 2017 5:44 pm

The world ocean is all connected, and so sea level change in one place is propagated to every other location over some period of time, but how fast does this occur?
At the same time this is occurring, currents are moving water around, as are the tides. And the wind is doing so as well. And all three are doing so in a separate and different and complicated manner, which is constantly changing for every point on Earth and for every second of every day (take a look at a detailed representation of the eddies and curlicues of the Gulf Stream, frinstince).
On top of this, going on at the same time, the Sun is shining on some areas of the ocean, some places brightly and at a direct angle, some places not so brightly and not as direct an angle, and this changes constantly due to clouds and the turning of the Earth, and varies as well by latitude, and the effect of latitude is constantly varying as the Earth proceeds in it’s orbit.
Near Antarctica this time of year, little Sun is hitting the southern ocean, and it is being swept by roaring winds of a cold temperature and varying humidity, which is sucking varying amounts of heat from the water from conduction and evaporation.
Near the Tropic of Cancer, the Sun is shining directly down and strongly warming the Ocean.
So the water is all the time contracting in some places, expanding in others, moving around, mixing up, and swirling hither and yon…and each of this changes is causing the volume and the level of the water to change, and these changes are being propagated outward at some speed or another…which speed probably varies as well.
So…you want an amount of rise or fall of the ocean for a certain change in temp?
Which temp is that?
Is that the average global surface temp?
The one which does not measure enthalpy but just a thermometer reading? Which takes no account of wind? Or anything else. And this temp…is it the fiddled with temp, or the straight reading?
Is there a “true” global average temp, which we would know if we were smarter and less smarmily political and had more thermometers and read them more accurately…or is the entire concept of global temp hokum, as some say it is?
Or are we comparing some local temp with some local sea level?
Plainly, given the above motions and variations, doing such locally would be a fools errand to try and measure.
Theoretically speaking, and all else being equal…is that the basis of the question (How much does the ocean height vary with a certain change in temp?)?
All else is not equal, and never will be on a round planet which is spinning and rotating and warmed on one side and cooled on the other and subject to all manner of jostling and pushing and pulling.
The dance may be too complicated to ever make into a diagram that can be eyeballed and reckoned with at a glance.
http://3.bp.blogspot.com/-euS8dNkoD7g/Uv3LDkxy2TI/AAAAAAAAAso/ObWFGy7BHBI/s1600/DanceSteps.jpg

Menicholas
Reply to  Geoff Sherrington
July 21, 2017 6:03 pm

“Sea level rise from the depths of the last glacial until the present interglacial is about 130 meters(!) Being generous, if we divide that number by 5C (thought to be the maximum global temperature difference from the last glacial to this interglacial) we get about 25 meters per degree Celsius. That means it takes a long time for everything to equilibrate with a change in surface temps…”
There is no equivalence between global average temp and sea level.
At some points in time, water from the oceans is accumulating on land and the ocean falls, and at other points in time, the water frozen onto land is melting, on average, and the volume of the ocean is increasing and presumably sea level is rising.
But wait a second there…we can look at temp reconstructions and see that at some certain “global temperature”, the Earth may be heading towards a glacial maximum and ice is increasing, or heading into and interglacial and ice is melting.
I think that trying to picture the Earth as an idealized cartoon diagram and drawing sweeping conclusions is silly, personally. Too many things are going on in too many places which may or may not be directly correlated or not, and the degree or lack thereof may be changing over time.
Besides…do we actually know if Antarctica and/or Greenland are gaining or losing ice?
Are there some years yes and some years no?
Ya gotta be crazy to think the people who purport to be studying this and telling everyone “the facts” are even able to know, let alone credible enough to believe.

July 20, 2017 7:04 pm

Great analysis
Thanks

JBom
July 20, 2017 7:08 pm

I would hazard that the Alarums, are more interested in issues of belief and spirituality than issues of measurement and the portrait of measurement by graph [Chart] (a method of René Descartes [Latin, Renatus Cartesius])!
“(c) Graph E in paper (5) is the key. As the world continues to warm, the rate of sea level rise will accelerate (probably slowly).”
Indeed! And Not! In this statement there is the presumption given without evidence or proof, “As the world continues to warm”.
Evidence shows this presumption false!
Only the Believers and Spiritualist will ignore evidence (i.e. measurement) because their God does not communicate Truth by measurement or Observation. For them “Truth” is revealed! … late at night … in a closet … sitting on a toilet … having sexual intercourse with a same-sex partner … watching a re-run of “Seinfeld” at 04:30 GMT (their way of getting instructions from God before the sun rise)!
But is not … TOPEX POSEIDON … measurement? … the monk cries.
Ah Ha! The “adjustments” … “the adjustments” … to confirm the desired … belief! Belief Must Rule! and Belief will be fed … to appease … Belief!
Belief

JohnWho
Reply to  JBom
July 20, 2017 7:26 pm

JBom –
I would politely ask that you rethink what you’ve said, ’cause a lot of truth has been discerned over the years while sitting on a toilet.
/grin

Rick C PE
July 20, 2017 7:40 pm

When a trend is essentially linear as Willis’s analysis indicates, fitting higher order polynomials will produce equations with very small coefficients for the higher order terms (x^2, x^3, …). Often these coefficients will be on the order of 10^-5 or -6. The result is essentially to approximate a simple linear fit.

Javert Chip
Reply to  Rick C PE
July 20, 2017 8:31 pm

Forest
Quaint Forest? What an old-fashioned word to use.
A little upset you didn’t pass the Willis test?

ferdberple
July 20, 2017 8:01 pm

Actually, sea level rise is very similar to global warming. Just like temperature, the daily change in sea level height due to orbital mechanics is much greater than any observed effect that might be due to humans.
It is only by removing mathematically the daily and seasonal variations in temperature and sea levels that one can claim that what remains is in any way significant. Otherwise it would be too small to notice.

KTM
July 20, 2017 8:04 pm

If a single tree can prove “global” warming, why not a single tide gauge?
http://www.psmsl.org/data/obtaining/rlr.monthly.plots/145.png

Lance Wallace
July 20, 2017 8:45 pm

Jevrejeva reported in her 2014 article an average rise of 1.9 mm/year/, with an acceleration of 0.002 mmyear/year, using a quadratic equation to get the acceleration. I took her data and verified the 1.9 mm/year, as well as the 0.002 mm/year/year acceleration. (I used a different method, not a quadratic equation but a fit to the first differences, which should give the same answer.) However, the uncertainty of the fit to the first differences was more than half of the value, meaning the acceleration was not significantly different from zero.
https://dl.dropboxusercontent.com/u/75831381/Jevrejeva%20sea%20level%20change.xlsx

Bill Illis
Reply to  Lance Wallace
July 21, 2017 6:58 am

I took ALL the tide gauges in the PMSL database and how each individual one changed each year from 1909 to 2009 (recognizing that they come and go.) 30,966 individual annual measurements
What you see is that there GROUPS which are either dropping fast, or rising fast or staying stable. This is glacial isostatic adjustment. Some tide gauges are rising at 12 mms per year and at least one is falling at 12 mms/year (and then some which have eroneous readings and vary too much to be valid).
This means that by simply cherrypicking which tide gauges to use, you can get ANY number you want and any acceleration value you want.
This is what Church and White have always done (a large number of gauges but picked in just the right way and never the same from study to study). The best method is to adjust each individual one for GPS land movement (which appears to be fairly stable) and then use as many as you can and use the same gauges over as long a time as possible.comment image

Reply to  Bill Illis
July 21, 2017 8:27 am

That is why the only correct sample is the subset of PSMSL that is both long record (>60 years) and diff GPS corrected for vertical land motion. There are about 70 such tide gauges out of about 148 with diff GPS. NH bias, but no reason to think that matters to global SLR given the bathtub effect. They show 2.1-2.2mm/year and most definitely no acceleration.

Gloateus
Reply to  Bill Illis
July 21, 2017 12:08 pm

Use Australia for the SH component. Little to no postglacial land adjustment there, thanks to so little glaciation during the last “ice age”.

Menicholas
Reply to  Lance Wallace
July 21, 2017 6:34 pm

“…0.002 mm/year/year acceleration.”
“…meaning the acceleration was not significantly different from zero.”
0.002 millimeters is 2 micro meters. 2 millionths of a meter.
Per year.
Or zero.
Hmmm…
Well just how big is two micrometers?
Can we think of some familiar objects of this size?
Well, a red blood cell is about 2 to 4 times this size…too big.
One wavelength of visible light is between about 1/3 and 2/3s of a micrometer…too small.
A human hair? Varies…are we talking blonds or brunettes? But at an average of 80 micrometers, we are way off anyways.
In any case, a micrometer is a distance too small to see.
Which means it might as well be zero for all the effect it will have on anything real.
But what gets me is this…someone trying to claim, with a straight face, that the body of water pictured below and extending clear around the never still Earth, the change in height of this, over a year, can be discerned to a level comparable to lining up ten virus particles in a row?
http://archive.sailingscuttlebutt.com/photos/04/bigwaves/1.jpg
This is actually pretty funny.
I wonder if it was an intentional joke?
https://youtu.be/i7WWrGxv1eg

JPinBalt
July 20, 2017 9:02 pm

Let’s see … if the annual 2 mm rise continues consistent with the last 150 years of data, and the top of the Statue of Liberty is 326 feet above water or 99,365 mm, then best calculation is that it will be under water in 49,683 years if you extrapolate current conditions.
Only problem is that we will be halfway into the next ice age by then with a mile of ice above where Chicago is now, so do not see from where the water could come being locked on land. Maybe you could walk in the cold from Manhattan to Statue of Liberty which would be on a big hill, but also enough time for another species of humans to evolve.
http://lh3.ggpht.com/-xi4vhYwxuGE/UJAZrxRnYHI/AAAAAAAABVI/isS6k-W6Qrk/NewImage.png

Gloateus
Reply to  JPinBalt
July 21, 2017 12:10 pm

And of course the world is not going to continue warming steadily for tens of thousands of years. There will be ups and downs, then descent into the next glacial epoch.

James at 48
Reply to  Gloateus
July 21, 2017 10:01 pm

“Killer AGW” activists claim we have defeated the glacial – interglacial oscillation. Endless interglacial. That’s what they purport.

catweazle666
Reply to  Gloateus
July 23, 2017 9:26 am

““Killer AGW” activists claim we have defeated the glacial – interglacial oscillation.”
Sounds like UK Chancellor of the Exchequer Gordon Brown’s 2003 claim that he had eliminated ‘Boom and Bust’.
That ended badly…

A C, of Adelaide
July 20, 2017 9:03 pm

I always think back to Akasofu’s 2010 temperature graph – if you have an oscillation superimposed on a linear trend – there will be times when it appears that there is acceleration and times that there appears to be a deceleration. The underlying trend is linear, ie not accelerating and sinusoidal, ie not accelerating.
As far as I see – this apears to be the same here, with the sea level data. 75-80 year oscillation superimposed on linear trend.
You would need to extract both those trends to see if there is a significant divergence.

Mydrrin
July 20, 2017 9:20 pm

Perhaps it’s at least partly cyclical, so likely not going logarithmic.
[imgcomment image[/img]

Mydrrin
Reply to  Mydrrin
July 20, 2017 9:26 pm

how do I add an image/graph to my post?

Mydrrin
Reply to  Willis Eschenbach
July 20, 2017 10:05 pm

Thank-you.

Reply to  Mydrrin
July 21, 2017 8:33 am

Sliding averages are a kind of running mean and bear all the same defects: a lot of noise shorter than filter period gets through ( look at all those spikes ) ; spurious peaks and troughs because of on inverted lobes in the filter frequency response.
If you want to filter that data you get a better result with a 48 month guassian. Compare.comment image

TimTheToolMan
July 20, 2017 10:54 pm

Willis quotes

(c) Graph E in paper (5) is the key. As the world continues to warm, the rate of sea level rise will accelerate (probably slowly).

I dont understand how they come to this conclusion as it simply doesn’t follow. Increased rate of sea level rise is dependent on the energy flow increasing but the temperature is dependent on the energy accumulating. Totally different and one doesn’t imply the other.

George Tetley
July 21, 2017 1:11 am

Sailing from San Diego to Auckland New Zealand, anyone telling me that sea levels are increasing 1.3mm a year needs a head Doctor !
(water, water everywhere and all the boards did shrink )

Wil Pretty
July 21, 2017 1:22 am

Willis
The aspect that i find difficult is that the sea level rise shows an abrupt change in 1850 and then a linear increase. The oceans are a large body of water. I cannot envisage a forcing that would generate such a response. I would expect the forcing to be sinusoidal. That would not generate such a response.

Hans Henrik Hansen
July 21, 2017 1:29 am

A (stupid?) question: Have your data been corrected for ‘uplift/subsidence’ (where the gauges stand) ??
In Denmark, where I live, such vertical movements are substantial – see example here:
http://www.fotoagent.dk/single_picture/10852/25/mega/Figur_4.JPG
(scale in mm per year)
I suppose there are similar movements where ‘your’ (63) gauges are located(?).

Reply to  Willis Eschenbach
July 21, 2017 7:27 pm

Juneau is rising at ~14mm/yr due to isostatic rebound.

JJM Gommers
July 21, 2017 1:37 am

On the site of the Dutch Government local sealevel rise is depicted linear at a rate of 1,9 mm/year(1890-2014) and includes a statement of no acceleration. A footnote on global sealevel mentioned acceleration.

Prolefed
July 21, 2017 1:47 am

Willis – thank you for your interesting post. I work in coastal engineering based in the UK, obliged to apply SLR scenarios that reflect the accelerating SLR hypothesis to scheme design. Compliant but sceptical, I point colleagues to the UC global mean SL satellite data record (’93 – ) which eyeballs no acceleration trend. Is this dataset too short to apply your statistical approach to, or did you simply go for the longest dataset(s) available?

Prolefed
Reply to  Willis Eschenbach
July 21, 2017 2:19 am

Thank you Willis – I wasn’t expecting a reply so soon – get some rest!

Robert from oz
July 21, 2017 3:01 am

And here’s me thinking I was the only one that had problems with that post and by the sound of it probably the least schooled .
Thank you for your work Willis and stellar job on the retaining wall , hope you put drainage in for the forthcoming Armageddon.

M Seward
July 21, 2017 3:41 am

I must say I find fitting relatively simple matehematical formulae to long term data of what is implicitly a very, very complex mechanism’s outcome is a bit reckless. In the example given we have the quadratic fit used to postulate that the trend for sea level rise on the out years ahead is ‘accelerating’ whereas a quick glance says that in about 1963 it had just stopped falling. Longer period data tells as this is nonsense so on what basis is the quadratic a meaningful ‘model’.
The worst, the dumbest, the most moronic example of this sort of frogshite ‘science’ was in apeper on sea evel rise where that tracked the western Pacific MSL over a reasonable time and loa and behold there was a periodic variation they attributed ( quite logically and correctly it seems) to the Pacific DEcadal Oscillation. Then the wheels fell off. They fitted a line to the data and got an uptrend! DOOM, we’ll all be droended etc. The trouble was the oscilating pattern clearly started on a trough and finished (after several cycles) on a peak so the ‘uptrend’ was just a conbstruct of that bit of idiocy. They would have got the same result if the data conformed to a pure sine wave which must have zero uptrend by definition.
Anyway whenever I see linear fits I just turn the page these days. Now a Fourier series I can come at but even that is dependent on getting a long enough data set.

Geoff Sherrington
July 21, 2017 4:34 am

Units and terminology please?
……………..
Sea level rise is a distance. A distance between a measured point and a reference point. A convenient unit is millimeters, mm.
This distance is not constant over time. The first derivative of distance with respect to time is velocity. Convenient units might be mm per year.
This velocity is not constant over time. The first derivative of velocity, being the second derivative of distance, with respect to time is acceleration. Units here are mm per year per year.
(Please excuse the lack of formal scientific notation for the units, a bit complicated for Word Press).
……………
There is no reason to mention the word “rate” because its use is confusing. I wonder what Larry Kummer really means by “the rate of sea level rise will accelerate”. Likewise with you Willis, “an accelerating rate of sea level rise”. Are we moving to the third derivative of distance? Heavens, no, do not go there. It is named the “jerk”.
I am being more than pedantic. For example, “rate” by itself has to be qualified to have meaning, like rate with respect to time, rate with respect to weight, rate w.r.t wavelength and so on through the physics library.
………………
The full meaning of sea level changes can be captured by the proper, basic, scientific variables of distance, velocity and acceleration, so why not use them and only them?
…………..
Also, a minor disagreement about choice of a quadratic to fit a non-linear response curve. Some recent papers have proposed that the global sea level curve is sigmoidal, with a velocity v1 from say 1900-60, a lower or even negative velocity v2 1960-90 or whenever, followed by a return to the original velocity v1 1990-today. There is no “one curve fits all different hypotheses”, but the quadratic is one of the worst fits for such a sigmoid.
………….
Never mind, Willis makes the point that no acceleration is seen in tide gauge data from goodness of fit studies over multi-decade terms like these. That is what is important.
Geoff

Menicholas
Reply to  Geoff Sherrington
July 21, 2017 6:54 pm

“Never mind, Willis makes the point that no acceleration is seen in tide gauge data from goodness of fit studies over multi-decade terms like these. That is what is important.
Geoff”
This thread and umpteen more like it demonstrate very well the principle that it takes far longer to debunk a load of BS than it does to spew it.
The ocean is right where it has always been, and although it acts up occasionally, it always goes back into it holding pen eventually.
The average position varies slightly over time, but it changes every day by far more than the average has changed over the lifetime of me, you, our parents, grandparents, great grandparents, and who knows who else.
But people who are good at making crap up and convincing others it is true, can run circles around dry facts like “Where is the ocean”?
Same as it ever was.
https://youtu.be/I1wg1DNHbNU

July 21, 2017 4:57 am

a comprehensive analysis of selection bias in tide gauge measurements between 1807-2010 indicated that (a) sea levels are only rising at a rate of about 1 mm/yr (as of 2010), and (b) a total of 65% of the world’s tide gauges have recorded stable to falling sea levels.
http://notrickszone.com/2017/06/05/sea-levels-are-stable-to-falling-at-about-half-of-the-worlds-tide-gauges/#sthash.ZzzcusEg.dpbs

July 21, 2017 5:30 am

Another long term view:
http://climate.mr-int.ch/images/graphs/sea_level.png
Note the steep rise-rate around 1800, and the multi-decadal rise-rate oscillations (over an increasing trend).

Hugs
July 21, 2017 5:47 am

there is still no evidence that the sea level rise is accelerating.

Willis, what do you think what is the reason that the recent years are a bit warmer, say less than a degree C than what the temps were when our great-grandparents were born, but that the seas rise so linearly as they do?
I think it is odd to see how linear the sea level change is. Freaking odd! I don’t see any good reason behind it.
I come up with two explanations. The land-based temps have little to do with ocean heat uptake and glacier melt. And of course, the linearity can be accidental, since it will not be linear forever. But assuming land-based air temp at 2m has been risen, is that just something that does not correlate with sea level rise?

tmlutas
July 21, 2017 6:06 am

Great analysis, but a pity that it seems to be episodic. By that I mean that it takes significant human work to do and isn’t likely to be done on an ongoing basis in an affordable manner. Isn’t this something that would better be done every month automatically with summaries for the general population that could be absorbed within a few seconds at most and ideally in the sub-second time frame?
And yes, I’m actually interested in setting up something like that. Contact me if you’re interested.

Menicholas
Reply to  tmlutas
July 21, 2017 8:20 pm

Yes, we need month to month updates for something which has not changed appreciably in a hundred and fifty years.

tmlutas
Reply to  Menicholas
July 25, 2017 4:33 pm

Yes, you do, because if you do that in an automated way, when somebody claims otherwise *as alarmists are claiming right now* they won’t be taken seriously.
The cheaper computing power gets, the more these sorts of calculations need to be done. Anything done once when it’s expensive should be done regularly when the task becomes trivially cheap because of reduced computing costs.

Joe - the non climate scientist
July 21, 2017 6:20 am

Church & White along with other studies show a rapid acceleration of the rate of sea level rise.
The tide gauges have gone from approx 1mm per year circa 1880’s to 2.0mm circa today. While the satelite measurements have gone from 3.0mm to approx 3.2-3.3mm circa today. Both the tide gauges and the satelite measures show a doubling of the rate of approx 100-150 years.
The acceleration is cited in the numberous studies appears to be mostly from the switch from tide gauges to satelite measurements. The remaining acceleration appears to be from the short term cyclical changes.

Reply to  Joe - the non climate scientist
July 21, 2017 10:41 am

Actually they don’t. The two Church and White papers I have studied used bith different time frames and different subsets of tide gauges. Apples to oranges. See my recent guest post on SLR and closure for more details.

chris y
Reply to  Joe - the non climate scientist
July 21, 2017 2:46 pm

Houston, J. R. and Dean, R. G., “Sea Level Acceleration Based of U.S. Tide Gauges and Extensions of previous global-gauge analyses,” J. of Coastal Research, Vol. 27, No. 3, pp 409 – 417 (May, 2011).
They used 57 U.S. tide gauge records from PSMSL with lengths of 60 – 156 years. They found a small deceleration from 1930 – 2010.
For global extent, they extended Douglas (1992) by 25 years, and analyzed revised data of Church and White (2006) from 1930 – 2007 and obtained small decelerations similar to the U.S. records.
Acceleration: -0.012 mm/yr^2 for U.S. or Global.

bitchilly
Reply to  Joe - the non climate scientist
July 21, 2017 4:50 pm

the notion of accurately measuring millimetres of sea level rise never mind thousandths of millimetres no matter what equipment is used is to me a nonsense.as usual a great expose of the numbers by willis ,but i fear the numbers at the outset bear no relation to reality,a consistent trend in climate science i believe.

Menicholas
Reply to  bitchilly
July 21, 2017 8:22 pm

How many tide gages and for how long use such a method?

steve in miami
July 21, 2017 7:34 am

The scatter plot is interesting, but I think it would be more definitive to plot linear vs linear+quadratic. N’est Pas?

July 21, 2017 7:53 am

Most interestingly, they have just found the missing sea level acceleration
https://www.scientificamerican.com/article/satellite-snafu-masked-true-sea-level-rise-for-decades/?utm_source=pdb&utm_medium=email&utm_campaign=07202017&variable=a553eadb90dd3b52fbf8d01481e04811
obviously if the data don’t match your dogma, you torture them, until they confess.

Martin Smith
July 21, 2017 8:14 am

Hi Willis. I think this analysis shows that your analysis is incorrect. Can you comment?
http://tamino.wordpress.com/2017/07/21/sea-level-rise-is-accelerating/#more-9358

Doug MacKenzie
Reply to  Martin Smith
July 21, 2017 9:55 am

Tamino throws in a red herring by declaring acceleration in Boston and deceleration in Juneau is evidence that Willis’s analysis is incorrect. But the claimed deceleration at Juneau is claimed to be caused by the reduced glacier mass attracting less ocean water. This case has been presented a number of times, always without reference. However, if you calculate from Newton’s law F=Gm1m2/r^2 for an estimate of the glacier melt and it’s average distance from shore, and apply some hydrostatics, you will find this claim to be highly exaggerated. Like most warmunist stuff, a small investment in truth yields a major return in catastrophic predictions, plus a major return in donations to the website.

Tom Dayton
Reply to  Doug MacKenzie
July 21, 2017 10:13 am

Doug: Gravitational effects of melting ice on local sea levels now is well established. An easy way to enter the literature is to search for peer reviewed papers by Jerry Mitrovica. Here is a brief lay explanation: http://nautil.us/issue/33/attraction/why-our-intuition-about-sea_level-rise-is-wrong

Andrew Cooke
Reply to  Doug MacKenzie
July 21, 2017 11:36 am

Tom Dayton, that was some painful reading. I always hurt mentally when I read a journalist’s interpretation of a discussion with a scientist. That was a lot of generalization and not a lot of detail and it, as usual, raises more questions than it answers.
How does this specifically have to do with Juneau? Is there an exceptionally large glacier nearby? Is it melting fast enough to show a true gravitational effect? Is the shape of the land nearby sufficient to justify this explanation? If this was all due to gravitational effects from local glaciers does that mean that only gauges near a glacier are showing this phenomenon? Are there any gauges in the tropics showing this downward slope? What’s the excuse for those?

Tom Dayton
Reply to  Doug MacKenzie
July 21, 2017 12:04 pm

Andrew, my suggestion was for you to search for the peer reviewed literature, which has details. Instead of complaining about the lack of detail in the brief lay explanation I was nice enough to point you to, why don’t you read the actual literature?

Doug MacKenzie
Reply to  Doug MacKenzie
July 21, 2017 2:31 pm

Tom, you make my exact point…referring to articles with no calcs….maybe you should study Mitrovica’s calcs yourself before you start sending me “lay information”. I did similar calcs for university physics assignments 40 years ago. And gravity, despite being “real physics” doesn’t explain the amount of Juneau deceleration. Try again.

Martin Smith
Reply to  Willis Eschenbach
July 22, 2017 1:11 am

Thanks Willis. Are you sure you used Tamino’s method? He doesn’t include it in his post. What method did you use to correct for autocorrelation?
Thanks.

Martin Smith
Reply to  Willis Eschenbach
July 22, 2017 3:59 am

Sorry, I didn’t see your update. Thanks.

bitchilly
Reply to  Martin Smith
July 21, 2017 4:52 pm

i am sure willis can/has commented,though i fear it would be a waste of time with the individual concerned.

July 21, 2017 8:28 am

Willis is mistaken—sea level rise is accelerating. See this post from Tamino: https://tamino.wordpress.com/2017/07/21/sea-level-rise-is-accelerating/

Andrew Cooke
Reply to  johnrussell40
July 21, 2017 10:01 am

I decided to follow the click bait, although I try to not do that very often. What followed was an interesting bit of “Willis is ‘insert insult here’ ” followed up with a discussion in statistical analysis. The p- value is then trotted out along with comments about how that is used to determine that sea level rise is accelerating.
How about this. Why don’t you show your full design of experiments. If you are going to trot out the p-value, you need to make sure you define the H0 and H1. Why? Because the p-value only is important if it allows us to reject the H0 or Null Hypothesis. I may be wrong but Willis’ H0 appears to be that it is a linear fit only. That means that the H1 would be that it is either statistically the same or the quadratic fits. That means the very low p-value would support the H1, which might be why Willis used the R^2 instead of the p-value.
Of course I could be wrong……..but if I am it is because no one has taken the time to express what their H0 or H1 might be. Don’t play around with p-values unless you plainly express your H0 and H1 values.

Michael Jankowski
Reply to  johnrussell40
July 21, 2017 4:00 pm

Tamino is a mistake himself.

Editor
July 21, 2017 8:34 am

Global Absolute Sea Level can not be determined from uncorrected Tide Gauge data. Tide Gauge data relates only and exclusively to Local Relative Sea Level. The relationship between each local Relative Sea Level and Global Absolute Sea Level is unknown without a great deal of additional data.
All Tide Gauge data, to be used outside of its proper place — determining local Relative Sea Level — must be first corrected with reliable precise information on the vertical movement (up and down) of the land to which the gauge is attached. The only truly reliable data on this comes from the NOAA CORS system.
Even when corrected, Tide Gauge data only speaks to the question of what the sea level is doing locally. Global Eustatic Average Sea Level ( “eustatic” refers to global changes in sea level relative to a fixed point, such as the centre of the earth) can not be determined from Tide Gauge data — nor can rates or rise or fall of global sea level.
Tide Gauge measurements are in effect measuring from a moving platform — the land — which moves up and down on its own, independent of the sea surface. The sea surface also moves up and down on short term cycles (tides) and long-term changes. The local long term changes are not linearly connected to Global Sea Level rise or fall. Local sea level may fall while global levels rise, and vice versa.
That said, all human related sea level problems are LOCAL. It only matters where the sea touches the land. New York cares not what the sea level is doing in Hong Kong, no NY subway is flooded by sea level rising in Hong Kong. If local sea levels are rising and it is a problem for that locality then whether or not Global Sea level is going up or down is irrelevant.

aporiac1960
Reply to  Kip Hansen
July 21, 2017 11:12 am

“That said, all human related sea level problems are LOCAL.”
Which is why all of the forecasts concerning sea level that have come out of decades of climate research have thus far have been of nearly zero practical use.

July 21, 2017 9:04 am

Why are so many of your R^2s in Figure 3 less than 0.5? Doesn’t this analysis similarly indicate that the linear trends are not statistically better than pure intercept models?

Reply to  drf5n
July 21, 2017 9:56 am

Good point !

Gloateus
July 21, 2017 11:19 am

Sea level is still lower than it was during the Medieval, Roman and Minoan Warm Periods and Holocene Climate Optimum.comment image

Gloateus
Reply to  Gloateus
July 21, 2017 11:59 am

Eemian interglacial sea level in the continental US, without benefit of a Neanderthal industrial age in Eurasia:
http://www.tobiasbuckell.com/wordpress/images/2013/01/NewImage3.png

Steve Fitzpatrick
Reply to  Gloateus
July 21, 2017 3:11 pm

Don’t know where that image came from, but it is mistaken. Maximum sea levels were 5 to 7 meters above those of today. Image shows all of Florida submerged. But look at an elevation map of Florida: http://ete.cet.edu/gcc/style/images/uploads/Sea%20level%20risk-FL.png
More than half the state is higher than 10 meters above sea level, and some 40-50 meters above sea level. Florida was not all under water during the Eemian.

Menicholas
Reply to  Gloateus
July 21, 2017 9:18 pm

That map shows a tongue of water extending up almost all the way to Illinois, past places that are 300 feet above sea level.
Although it also shows Philadelphia, at about 40 feet, not under water.

David
July 21, 2017 11:34 am

I guess one thing I have never heard people talk about is how we are draining ground water, that used to never be used. We pull millions of acre feet of water out of the ground every year that finds its way to the oceans. This water used to not be on the surface! I have a well from an aquifer that is essentially not refilling and has enough water for our little area for about 50-100 years.

Gloateus
Reply to  David
July 21, 2017 11:37 am

The effects of ground water irrigation on sea level has been discussed on this blog fairly often.

July 21, 2017 11:54 am

Hmm. You seem to be unaware that simply comparing R^2 values is no way to compare how well two models characterize the process that generates a set of data. That should be pretty obvious from just LOOKING at your Figure 1.

TimTheToolMan
Reply to  Patrick Shoemaker
July 22, 2017 12:24 am

Patrick wrote

Hmm. You seem to be unaware that simply comparing R^2 values is no way to compare how well two models characterize the process that generates a set of data.

in response to Willis’ article where Willis wrote

So that is what I planned to look at—whether the difference between the R^2 for the linear and the quadratic fits is greater than the sum of their standard errors.

So Willis wasn’t even trying to characterize the process generating the data. That wasn’t even his aim. He even said he was fitting the data.

Frank
July 21, 2017 12:18 pm

Willis: I think the “standard method” for detecting acceleration in SLR is to perform a fit to
h = at^2 + bt + c
and then look at the confidence interval for a. And that requires correcting for autocorrelation (in the residuals). I’ve tried this with the satellite altimetry record (before the recent correction) and found a small acceleration with zero barely within in the 95% ci. In that case, the R2 for the linear and quadratic fits were essentially the same (0.97 and 0.98).
More importantly, currently SLR is about 1″/decade and we need to experience an acceleration of 1 inch/decade/decade to reach about 1 m of SLR by the end of the century. Even the high end of the 95% ci was well below this value.

July 21, 2017 1:18 pm

Willis, thank you for your essay.

RAH
July 21, 2017 1:38 pm

Ok. Though this is a statistical methods argument this truck driver has a more direct question.
Where the hell is the water coming from? Most of the Antarctic is gaining SMB. Though Greenland ice sheet SMB was decreasing a little it is now gaining. Neither can account for the amount of SLR it seems to me.
Thermal expansion and ground water are accounting for the bulk of the rise?

Reply to  RAH
July 21, 2017 2:24 pm

Thermal expansion and creative accounting are apparently the two main drivers of SLR… 😉

afonzarelli
Reply to  RAH
July 21, 2017 3:56 pm

comment image

stevefitzpatrick
Reply to  RAH
July 21, 2017 4:44 pm

Thermal expansion, ground water pumping, and melting of high altitude glaciers are all contributors. There probably is some net accumulation of ice in the Antartic, but I think Grace data continues to indicate net loss in Greenland. That said, claims of more than a meter sea level rise before 2100 are utterly bonkers…. more likely is somewhere under 50 cm by 2100. The Statue of Liberty is safe…. though the liberty the Statue celebrates is truly threatened by those who insist people must “fundamentally change” how they live their lives to ‘avoid catastrophe’. It’s just science being subverted and corrupted to advance green/left policies..

RAH
Reply to  stevefitzpatrick
July 22, 2017 4:05 am

Thank you to those that responded.
GRACE data on ice masses overlaying areas like some in Greenland which have ongoing active geological/ Geothermal processes seems to have been less than optimal.
Afonzarelli.
Your chart runs to 2014 but there has been more than one paper published since then which has indicated the SMB of Antarctica is actually growing slightly. That would indicate that the contribution from Antarctica would be negative.
As for the Steric contribution that would correlate with the higher SSTS.
I guess over all one should expect that if that chart ran to the present the total would be somewhat less?

Brian
July 21, 2017 1:52 pm

Forrest,
It’s not clear that you understand what Willis is doing. You are correct that a linear model might not be the best model for sea-level rise, but Willis isn’t trying to model sea-level rise. He is looking for evidence of acceleration.
As you may or may not know, any finite and continuous function can be represented by a power series. So whatever the correct model for sea level is, it can be represented by the series d(t) = a0 + a1*t + a2*t^2 + …. a0 would be a constant sea level, a1 is a constant change in level, a2 is a constant acceleration, etc. If there is any acceleration in the data, it will show up as a nonzero a2, no matter what the correct model is. That’s why the linear vs. quadratic fit is the right test to do.
It’s true that such a fit would not work prior to 1950, but it does allow Willis to conclude–correctly–that there is no evidence of acceleration between 1950 and 2015. That’s all his post is about and he did the test the way it should be done.

Brian
Reply to  Brian
July 22, 2017 10:10 am

Forrest,
I can see that you don’t understand what I’m talking about. I am not presenting some “ideas.” I am stating basic mathematical facts, known to anyone with a decent knowledge of calculus.
If sea level can be calculated at all (which you are assuming when you speak of a model), it is certainly a continuous and finite function of time. If sea level is definable at all (such as the average of sea-level gauges around the world), it is calculable for every moment in time. Since it is nonphysical for the sea to suddenly be, say, three inches higher without going through intermediate heights (such as 1 inch, 2 inches, etc.), it is certainly continuous. And since it is also nonphysical for the sea level to be infinitely high, it is also finite. Any accurate model of sea level, then, would also be continuous and finite. Again, these are not ideas, just simple facts based on common sense and basic calculus.
So why is Willis justified in stopping at the quadratic term? Because he’s only looking for evidence of acceleration. Suppose the actual model is more than quadratic. The we could rewrite the series as
d(t) = a0 + a1*t + (a2 + a3*t + a4*t^2+..)*t^2.
The third “constant” (the part in parentheses), which now depends on time, is the true acceleration. For Willis’s best fit, it will be calculated as a single number, basically the average acceleration over the chosen time interval. But it will be nonzero if there is any acceleration at all. If it is zero, then all true constant terms (a2, a3, a4, …) must be zero also.
Take a look at Willis’s update based on Tamino’s criticism. The direct approach is to see if the term in parentheses is actually zero. It is. But what Willis did originally is still correct, if less direct.

seaice1
July 21, 2017 4:17 pm

Your analysis seems to show that an accelerating fit is perhaps marginaly better than a linear fit (a few more points above the line than below it), but essentially both are just as good. It seems that this simplistic analysis is unable to differentiate between linear and rising, and it is not possible to distinguish between them using this method.
Thus an accereraing sea level is just as likely as a linear one, from this analysis.
This seems to show that this is not a good way to distinguish between linear and rising rates.

1sky1
July 21, 2017 4:48 pm

Those interested in a professional view of what Walter Munk calls the “enigma’ of sea level should read: http://www.pnas.org/content/99/10/6550.full
Those seriously interested in the question of accelerating SLR on a global scale will recognize that a sparse sampling of tide gauge records examined only via regressional methods applied on a time-scale dictated solely by data availability doesn’t provide a scientifically satisfactory answer.
On a Friday afternoon, I can’t take the time to replicate a longer comment explicating these two issues, which totally disappeared, because WUWT was “not responding” to my submission.

afonzarelli
Reply to  1sky1
July 21, 2017 5:08 pm

1sky1, they’ll eventually show up… (it’s been happening to everybody of late)

1sky1
Reply to  afonzarelli
July 22, 2017 4:20 pm

I’ll believe it when I see it. Another comment disappeared on this thread early this afternoon.

July 21, 2017 7:05 pm

Willis is an a-hole.

There is no such thing as a” lunar tidal cycle is just over fifty years”

No wonder he can’t get anything published. he’s an idiot.

Reply to  Steve Heins
July 21, 2017 7:10 pm

The Metonic cycle is 19 years.

afonzarelli
Reply to  Steve Heins
July 21, 2017 10:43 pm

Willis may be a lot of things, but one thing he ain’t is an idiot. (watch your manners steve)…

Menicholas
Reply to  Willis Eschenbach
July 22, 2017 1:00 pm

The “here” link does not seem to work.

Rob Bradley
Reply to  Willis Eschenbach
July 22, 2017 3:24 pm

Willis fails again….
“In addition, there is a cycle which is three of the 18-year cycles, so it’s just over fifty years (54 years 34 days, if you’re interested).”

The Nodal tide cycle is 18.6 years, so please try multiplying 18.6 by three. The answer is 55.8.
..
http://geology.geoscienceworld.org/content/1/3/141
..
But seriously, there is no 50/54 year cycle. Three revolutions the minute hand on a clock is not one minute, it’s THREE.

Reply to  Willis Eschenbach
July 22, 2017 6:00 pm

“a short “Communications Arising” in Nature magazine?”

Congratulations on getting a comment published.

Maybe if you try real hard, you can get an article published.

Menicholas
Reply to  Willis Eschenbach
July 22, 2017 7:10 pm

Whoof…tough crowd.
Rob and Steve must be great fun at parties.

Reply to  Willis Eschenbach
July 23, 2017 12:02 pm

Thank you Willis for your link to Communications Arising.
..
I especially like this sentence: “Critical comments on recent Nature papers may, after peer review, be published online as Brief Communications Arising”

Please note I highlighted the most important word in the description for you. A “comment” is a “comment” even if it is “peer reviewed”

Reply to  Willis Eschenbach
July 23, 2017 9:11 pm

Wow, so your comment got cited?

It’s still just a comment. That’s what the link says……”Communications Arising” are peer reviewed comments.

Reply to  Willis Eschenbach
July 23, 2017 9:23 pm

PS, if it took you all that time effort and energy to get a simple comment published, can you imagine how many YEARS it would take you to get a real research article published in Nature?

July 21, 2017 8:06 pm

Rising sea vs. water pump. Pump won. Dutch drained the sea in Flevoland (1,419 sq. km.)
King Canute at work. Who’s laughing now?comment image

July 22, 2017 3:23 am

I suspect the difference is in how we account for autocorrelation. I use the method of Koutsoyiannis, detailed here. I don’t know how Tamino does it.
I think Tamino models the autocorrelation as ARIMA(1,1) noise.
https://www.researchgate.net/publication/265467321_Time_and_tide_analysis_of_sea_level_time_series

1sky1
Reply to  Phil.
July 22, 2017 2:20 pm

After modeling the sample autocorrelation as an ARIMA(1,1) process, Tamino proceeds with the quaint notion that geophysical power spectra need to be compensated for autocorrelation, akin to the compensation of confidence intervals for linear regression. Since the power density of a random signal is defined by the Wiener-Khintchine theorem as the Fourier transform of its acf, his ensuing chain of calculations and conclusions is inane.
Koutsoyannis fares scarcely better, because he posits an AR(1) process a priori as characterizing the acf, thus making it totally dependent upon the sampled value at lag one. This greatly oversimplifies most geophysical data, especially when wave motion is involved.
Acceleration is intrinsically a high-frequency phenomenon, since it is determined by the second derivative in the case of analytic functions. In the practical case of discretely sampled signals, its power transfer function is distinctly high-pass, being proportional to sin^2 in the baseband interval 0 to pi/2. If we are to discuss acceleration of SLR scientifically, an objective choice needs to be made for any smoothing to be applied to best display the salient signal characteristics. The smoothing supplied by linear regression over the length of available data does not meet that requirement.

Menicholas
Reply to  1sky1
July 22, 2017 6:52 pm

Oh, the “dazzle them with bullsh!t” approach, is it now?

Menicholas
Reply to  1sky1
July 22, 2017 7:06 pm

No matter how you slice it, or how many times you pass your high dollar value word salad through the vegematic slicer dicer, the Mark 1 eyeball still shows the truth, plain as daylight.
No acceleration is evident.

Reply to  Phil.
July 22, 2017 6:05 pm

Sorry that should be ARMA(1,1).

1sky1
Reply to  Phil.
July 24, 2017 12:25 pm

See the smoothed 15-yr rate of change of sea level:comment image
If there were no accelerations and decelerations, the plot would be nearly flat.
To rank amateurs, most scientific descriptions are just “high dollar value word salad.”

Kurt in Switzerland
July 22, 2017 5:11 am

Reposted from a comment to the Larry Kummer article from 20 July:
Perhaps the author(s) are unaware of the Gregory et al. assessment from a few years ago:
http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00319.1
Abstract
Confidence in projections of global-mean sea level rise (GMSLR) depends on an ability to account for GMSLR during the twentieth century. There are contributions from ocean thermal expansion, mass loss from glaciers and ice sheets, groundwater extraction, and reservoir impoundment. Progress has been made toward solving the “enigma” of twentieth-century GMSLR, which is that the observed GMSLR has previously been found to exceed the sum of estimated contributions, especially for the earlier decades. The authors propose the following: thermal expansion simulated by climate models may previously have been underestimated because of their not including volcanic forcing in their control state; the rate of glacier mass loss was larger than previously estimated and was not smaller in the first half than in the second half of the century; the Greenland ice sheet could have made a positive contribution throughout the century; and groundwater depletion and reservoir impoundment, which are of opposite sign, may have been approximately equal in magnitude. It is possible to reconstruct the time series of GMSLR from the quantified contributions, apart from a constant residual term, which is small enough to be explained as a long-term contribution from the Antarctic ice sheet. The reconstructions account for the observation that the rate of GMSLR was not much larger during the last 50 years than during the twentieth century as a whole, despite the increasing anthropogenic forcing. Semiempirical methods for projecting GMSLR depend on the existence of a relationship between global climate change and the rate of GMSLR, but the implication of the authors’ closure of the budget is that such a relationship is weak or absent during the twentieth century.
Notice the final sentence. Such honesty is rare these days.

July 22, 2017 6:24 am

I’ve been having a running debate on this on Twitter with those who think there is acceleration. When I posted that not one surface station shows acceleration, the rebuttal from some is GLOBALLY together they show acceleration. So, 300 cars with a speed of 50kph collectively show an acceleration to 100kph, even though not one speedometer shows anything but 50kph. Got it.
Another demanded I show all stations to see there is no acceleration. I post a handful from around the world and state categorically that’s all I need to do to show not one station shows acceleration. That for there to be acceleration at some stations and not others would mean those with no acceleration are some how defying gravity.
Yep, in the world of AGW alarmists the laws of physics dont apply.
They also look for ANY acceleration at all, as if even a tiny little temporary acceleration is proof there will be a 2 meter rise by 2100. Again, this shows their complete lack of understanding and their desperation for anything to grasp.
To get to 2 meters by 2100 would require an acceleration (compound growth) of 3.7% per year. The least understood concept is compound growth. All compound growth has a doubling period. Each doubling period is the same as all previous doubling periods combined. This means that by 2099 sea level would have to be rising 8cm in that one year alone. Impossible.
Lastly, if you look at their graphs they show a rate of 1.7mm per year until 1990, then suddenly in that year, the rate of rise DOUBLED (100% acceleration) to a stable 3.3mm per year. No explanation how that could happen.
(I’d like to post some graphics, but have no idea how to do that, can someone post how, pls?)

Menicholas
Reply to  J. Richard Wakefield
July 22, 2017 1:14 pm

If you have a link that is a jpeg from a host website, just copy the web address on a separate line where you want the graphic.
You cannot post graphs you have saved on your computer…they have to be in the form of links to a website.
Or so I believe.
Up top, just below the site name, there is a row of tabs…one is to a test page…use it to test out what you want to do to see if it will work.
I am no eggspurt, but I know those few things.
As for sea level rise…the amount they claim is ludicrous…not based on evidence, just makin’ stuff up.
Many predict rates of rise that would rival meltwater pulse 1A.
Personally, I have mostly given up on arguing with people I do not know on social media sites.
It is truly pointless.
But sites like this and a few others are different…they are places that people can go for non-fake news, and false statements should not go unchallenged.
Even at congressional hearings run by guys like Ted Cruz, or news network programs like Tucker Carlson…many false statements go unchallenged, just slide on by, perpetuating all matter of *insert your favorite phrase for crap that aint true*.

Reply to  Menicholas
July 22, 2017 4:01 pm

Thanks, lets see if that works.comment image

Reply to  Menicholas
July 22, 2017 4:03 pm

It does so here is another. This is what surface stations should look like if the rate doubled in 1990:comment image

Reply to  Menicholas
July 22, 2017 4:06 pm

This graphic is common showing sea level rate accelerating instantly in 1990. With some comments I’ve added.comment image

Menicholas
Reply to  Menicholas
July 22, 2017 6:49 pm

Oh I get it…you hate children.
Why do you hate children?
/sarc off

Yawrate
July 22, 2017 7:47 am

I have perhaps a stupid question. Could not plate tectonics contribute to sea level variation?

Reply to  Yawrate
July 22, 2017 7:53 am

It does, which is why Alaska’s land is rising (sea level falling).

Yawrate
Reply to  J. Richard Wakefield
July 22, 2017 8:04 am

And what about those ever growing mid oceanic ridges?

Menicholas
Reply to  J. Richard Wakefield
July 22, 2017 1:19 pm

There are spreading centers, but also subduction zones.
Some seem to think Earth is expanding.
What it comes down to is, the total change in the level of the ocean over the past 150 years would not be even detectable if all you went by was pictures or where the beaches are.
Except for places where land has been displaced vertically by geologic forces, and where erosion has taken place…there is no place in the world where anyone could live in 1867 that they cannot live now because the ocean is too high. No one’s house has been flooded due to gradually rising oceans.
Storms…different story.

Prolefed
July 22, 2017 9:06 am

Has anyone applied ‘Tamino’s method’ to the UC satellite data record?

July 22, 2017 10:19 am

Whatever any future sea level acceleration turns out to be, it is very unlikely to put the Statue of Liberty underwater anytime soon …
As long as we don’t get any storms. Sandy closed Liberty Island for 8 months (75% 0f the island was flooded) and much of the infrastructure was destroyed. Here’s the dock before and after.comment image

Menicholas
Reply to  Phil.
July 22, 2017 1:21 pm

We will get storms. No matter what.
Did you have an idea that events which have always occurred can be stopped by political decree or virtue signaling obeisance?

Reply to  Phil.
July 24, 2017 7:08 am

Menicholas July 22, 2017 at 1:21 pm
We will get storms. No matter what.
Did you have an idea that events which have always occurred can be stopped by political decree or virtue signaling obeisance?

Flooding of Ellis Island and Liberty Island haven’t ‘always occurred’. Perhaps the rise in sea level there of a foot or so over the last century had something to do with it?

Svend Ferdinandsen
July 22, 2017 12:10 pm

You could use the Holgate-9 series of stations, as those stations are well known and spread around the globe.

Svend Ferdinandsen
Reply to  Willis Eschenbach
July 23, 2017 11:46 am

The best i can do is ask you to look at http://climate4you.com/
And specifically sea level and this one: http://climate4you.com/images/Holgate-9_Since1900-NEW.gif
It is mentioned which stations are used.
I belive it is the same stations all the time, so even if the rate could be a little different from other compilations, the change of rate must be usefull and valid.

Rob Bradley
Reply to  Willis Eschenbach
July 22, 2017 6:36 pm

1) ” that the longer cycle is about three of the 18-year cycles.”
2) “there is no Nodal tide cycle.”

Therefore there is no 54/55 year cycle

(basic logic Willie) …

PS, Google is your friend, I suggest browse the 1660 results you get for a search on “Nodal tidal cycle”

PPS, the solar system is darn good clock. We have things called “days,” and “years” based upon the clock like precision of the movements of the planets. The orbit of the moon is quite predictable.

Menicholas
Reply to  Rob Bradley
July 22, 2017 7:26 pm

Rob, if you read the post and the actual words Willis used, you will see he referred to the saros cycle, which is a period of 223 synodic months.
This cycles has been known since ancient times, and was what allowed certain cultures and not certain others to be able to predict eclipses.
Willis did not refer to the somewhat longer period known as the nodal tidal cycle. You seem to have translated one into the other inside your own head…those words are yours, not his.
BTW…223 synodic months is an interval known to great accuracy.
It is “approximately 6585.3211 days”.
Or, more simply, 18 years, 11 days, and 8 hours.
Three times that gives an even number of days.
And that three saros cycle period is exactly the number Willis cited.
I do not even have to break out my mark one pencil to do that multiplication.
Although I did do something you seemed unable or unwilling to do…I looked up stuff before I decided i was remembering correctly and criticized anyone.
You should try it sometime.
https://en.wikipedia.org/wiki/Saros_(astronomy)
https://en.wikipedia.org/wiki/Lunar_standstill

Rob Bradley
Reply to  Rob Bradley
July 22, 2017 7:43 pm

Menicholas: re-read the post, and focus on this: “Because the long lunar tidal cycle is just over fifty years”

See the word “tidal?”

You claim “if you read the post and the actual words Willis used, you will see he referred to the saros cycle”
….
Nope, he mentions that in a comment, but not in the post. Do you know the difference between the post, and the comments?

Menicholas
Reply to  Rob Bradley
July 22, 2017 7:53 pm

Ba-zing!
Ooh, you got me there!

Menicholas
Reply to  Rob Bradley
July 22, 2017 8:02 pm

I think it is worth noting that your rude comment was attached to his comment (did i use the right word…um, yup, I think so this time), not to the headline post.
Notice when you make a comment on a post, or on another comment…just what the little oblong button thingy says that you hit in order to …um…POST IT…says?
That one right down there on the bottom right as you POST your next rude-ass COMMENT to me.
See it?
What does it say?
If I had known this was grammar N@zi day, I would have peer reviewed each word of the comment I um…posted.
My bad.
So, your rude ass comment you posted in which you pulled the phrase no one else had mentioned out of your, uh, hat and attributed it to someone who had not said that…that was a reference to the top article?
But the words you quoted were not from up top.
So, like all warmistas…you just make crap up all day long.
It is like a reflex with you guys, aint it?

Rob Bradley
Reply to  Rob Bradley
July 22, 2017 8:12 pm

If you have a point, could you please make it?

There’s not much point in talking about sea level, which is measured with tidal gauges, and confusing it with an eclipse(s) that follows a saros cycle. Maybe you should direct your ire at Willis, since his sloppy writing and confusion about different cycles would best be solved with your help.

Menicholas
Reply to  Rob Bradley
July 22, 2017 9:01 pm

Just admit it…you did not know the difference between saros and nodal tide cycles. Or that there was one.
You conflated them and made a false attribution.
It is right there in black and white for all time.

Rob Bradley
Reply to  Rob Bradley
July 23, 2017 7:05 am

If it will make you happy Menicholas, I will admit that Willis did confuse the two.

Menicholas
Reply to  Willis Eschenbach
July 22, 2017 7:48 pm

“And the 54+ year cycle returns even more closely to the same point.”
I love this graphic animation, which illustrates the variation between one eclipse and the next one in that saros series:
http://eclipse.gsfc.nasa.gov/SEsaros/SEsaros136.html
Turns out NASA is still good for something.
A few somethings…just not anything related to climate.

Menicholas
Reply to  Menicholas
July 22, 2017 7:49 pm

Oh, wrong link.
This is the one:comment image

Menicholas
Reply to  Menicholas
July 22, 2017 10:19 pm

I do not know why it is that little square, but when I click on it I get the GIF from a wiki article.
it is the progression over one saros series of the path of each eclipse n the series.
Interesting pattern.
I wonder if each saros has a similar pattern?

Menicholas
Reply to  Menicholas
July 22, 2017 10:19 pm

Do you not see the GIF if you click the link?

crackers345
July 23, 2017 7:03 pm

Willis, to get the acceleration, did you remember to multiply the quadratic coefficient by 2?

Martin Smith
July 24, 2017 12:22 am

Willis, it looks like you have simply assumed that the 50+ year cycle you refer to has a significant effect on tides. I don’t think you have justified that assumption, so it looks like you have simply declared it so that you can ignore 95% of the 1,505 tide stations. Is there a paper that shows the effect of this cycle on tides?

Martin Smith
Reply to  Willis Eschenbach
July 24, 2017 11:26 am

I apologize for giving you that impression, Willis, but I was careful not to accuse you of anything. If you reread my comment, you will see that I did not accuse you. I said that your blog post “looks like” you are trying to ignore most of the data because you did not include the justification which you have just now provided. However, the word “lunar” does not appear in the paper you provided. The word “moon” does appear exactly once, and it does appear in the context of an 18.6 year cycle, but there is no mention at all of a 50+ year cycle, so you still have not justified your claim that this 50+ year lunar tide cycle is of significance. I’m afraid it still looks like you are trying to ignore most of the data. I’m not accusing you; it “looks” that way to me because I can’t see that you have justified your assumption.
But you are certainly wrong about your readers not having a clue what your motives are. We have all your blog posts.

Martin Smith
Reply to  Willis Eschenbach
July 24, 2017 11:51 am

From reading only two comments from me, do you really think you can reasonably make this claim?: “It looks like Martin Smith spends most of his time ignoring the truth and spreading lies”
You actually have not justified your claim that there is a 50+ year lunar tide cycle that has a significant effect on sea level rise. You haven’t done that, but your argument depends on it.

Martin Smith
Reply to  Willis Eschenbach
July 24, 2017 1:10 pm

>They say you need fifty years in order to get accurate estimates of “the tidal amplitudes and phases”
No they don’t.
I accept that you will not address the point I raised, so I will conclude by stating my understanding of your analysis: You throw out almost all the SLR data, and then you conclude from the remaining small fraction of the data that the SLR data do not show a statistically significant acceleration in SLR.

Martin Smith
Reply to  Willis Eschenbach
July 24, 2017 9:11 pm

Willis, here again is my understanding of your analysis:
You throw out almost all the SLR data, and then you conclude from analyzing the remaining small fraction of the data that the SLR data do not show a statistically significant acceleration in SLR.
You did throw out almost all the SLR data. That’s a fact. Did you conclude from analyzing the remaining small fraction of the SLR data that the SLR data do not show a statistically significant acceleration in SLR? Is that your conclusion, based on the data you analyzed?

Reply to  Willis Eschenbach
July 25, 2017 5:40 am

I’ve got an interesting debate going on at your friend’s site. Seems they dont like the fact that sat data shows a doubling of sea level in the 1990-1993 period and flat since. https://tamino.wordpress.com/2017/07/24/boston-sea-level/#comment-99191
Too bad you’re banned. Guess I will be too soon.

Martin Smith
Reply to  J. Richard Wakefield
July 25, 2017 5:46 am

J, why don’t you prove your claim (I think you mean doubling of sea level rise rate, not doubling of sea level) instead of just declaring it?

Reply to  Martin Smith
July 25, 2017 9:08 am

The doubling of the rate of rise, from 1.7mm up to 1990 to 3.4mm afterwards comes from the sat data. Surface station data shows no doubling. The sats are wrong.

Martin Smith
Reply to  J. Richard Wakefield
July 25, 2017 9:11 am

No it doesn’t, J. Tamino has explained where and why your claim is wrong. I won’t repost Tamino’s work here, but you now know why your claims are wrong, so it is really disingenuous to make the same claims here.

Reply to  Martin Smith
July 25, 2017 9:57 am

No he has not. He’s trying to shoehorn an acceleration curve onto a clear straight line data set. It is his OPINION that fits better than a straight line.
Here is the sat data, again. How you dont see a straight line is beyond me. Interesting how your side has turned into the deniers.comment image?itok=amqLr7zW

Martin Smith
Reply to  J. Richard Wakefield
July 25, 2017 10:40 am

J, the straight line you see is computed by simple linear regression. It always computes a straight line through any set of data. The straight line is the trend. There is always a straight trend line through the data. It is the trend. It always exists, but it says nothing about whether sea level rise is accelerating.

crackers345
Reply to  J. Richard Wakefield
July 25, 2017 11:07 am

Re: “the sats are wrong”
local sea rise from local gauges is contaminated by local changes in land height, which can be significant. sats are clearly superior.

Reply to  crackers345
July 25, 2017 1:15 pm

If they are superior, how come a calibration went unnoticed for 20 years? Sat data is rot with a lot of uncertainty and noise.
“In addition, the amplitude of the residual trend pattern is significantly lower than the expected error in trend patterns from satellite altimetry (in the order of 2 mm/yr to 3 mm/yr) and therefore suggests that satellite altimetry measurement is still not accurate enough to detect the anthropogenic signal in the 20 year tropical Pacific sea level trends. ”
https://tel.archives-ouvertes.fr/tel-01317607/document

Martin Smith
July 25, 2017 11:32 pm

“Sat data is rot with a lot of uncertainty and noise.”
Remember that, next time you tout satellite data as the best temperature data we have.

Reply to  Martin Smith
July 26, 2017 10:09 am

I’ve never relied on sat temp data. The only measurements I accept are the direct ones on the ground.

Martin Smith
Reply to  J. Richard Wakefield
July 26, 2017 10:15 am

Good for you. Then you know there was no “pause” or “hiatus” in global average temperature rise, and you know the global average temperature rise is accelerating.

Reply to  Martin Smith
July 26, 2017 11:36 am

And what is the rate of this acceleration? Do we expect the earth’s temp to double in the next few decades?
No, I dont see temps “accelerating” anywhere on the planet. If anything Tmax is down or flat:comment image

Martin Smith
Reply to  J. Richard Wakefield
July 26, 2017 11:48 am

I don’t know what your graph represents, J, because you don’t provide any links or citations. Clearly, it is not the global average temperature, which is what you and I are talking about. Apparently your graph shows the summer maximum temperature for somewhere. It says nothing about the global average temperature, which, again, is what you and I are talking about. Here is the complete explanation you are missing. It shows the global average temperature is rising, and the rise is accelerating. But no, I have not done the statistical analysis Tamino has done. The data are also available for each graph:
http://data.giss.nasa.gov/gistemp/graphs_v3/
And here is the statistical analysis by Tamino:
http://tamino.wordpress.com/2017/01/18/global-temperature-the-big-3/
So I say to you again: Good for you. Then you know there was no “pause” or “hiatus” in global average temperature rise, and you know the global average temperature rise is accelerating.

Martin Smith
July 26, 2017 9:03 am

Willis, won’t you answer my question? Here is my understanding of your analysis:
You throw out almost all the SLR data, and then you conclude from analyzing the remaining small fraction of the data that the SLR data do not show a statistically significant acceleration in SLR.
You did throw out almost all the SLR data. That’s a fact. Did you conclude from analyzing the remaining small fraction of the SLR data that the SLR data do not show a statistically significant acceleration in SLR? Is that your conclusion, based on the data you analyzed?

Reply to  Martin Smith
July 26, 2017 10:10 am

You have to throw out incomplete data, or records of too short a period. You cant include them because it incorrectly skews the results.

Martin Smith
Reply to  J. Richard Wakefield
July 26, 2017 10:17 am

I think we should allow Willis to answer for himself, J.

Reply to  Martin Smith
July 26, 2017 10:13 am

For example, in Canada only 13 stations in the Environment Canada’s database have a complete record of temps going back to 1900, even though at the height EC had 1300 stations in the mid 1980s. Now they are down to less than a third of that. Hence when looking at an as complete record as possible one can only use the 13 stations.

Martin Smith
Reply to  Willis Eschenbach
July 26, 2017 9:47 pm

No, Willis, not the “same” noise issues, different noise issue. But yes, all satellites face noise issues. The noise issues for “passive microwave reading satellites” are probably worse, yes? Multiple altitudes; multiple frequencies; clouds… That’s harder than bouncing radar waves off the ocean, isn’t it? Clouds don’t bother radar so much, do they? And there is only the one sea level to measure. There waves and wind conditions, of course.
But let’s return to our discussion. Will you answer my question? Here is my understanding of your analysis:
You throw out almost all the SLR data, and then you conclude from analyzing the remaining small fraction of the data that the SLR data do not show a statistically significant acceleration in SLR.
You did throw out almost all the SLR data. That’s a fact. Did you conclude from analyzing the remaining small fraction of the SLR data that the SLR data do not show a statistically significant acceleration in SLR? Is that your conclusion, based on the data you analyzed?

Martin Smith
Reply to  Martin Smith
July 26, 2017 11:50 pm

Willis, you wrote: “…but that doesn’t mean that all satellite datasets are equally bad as you are claiming.”
I did not claim that. In fact, I claim the satellite datasets used for inferring temperature are much more noisy than the satellites used for measuring sea level. I don’t know for sure, of course, but doesn’t it seem reasonable given the more complicated problem for inferring temperature from irradiance data measured at different frequencies for different altitudes, and given the problem of clouds getting in the way?
And now you write: “I already answered that, perhaps you weren’t paying attention.”
No, you didn’t. Will you answer my questions? You throw out almost all the SLR data, and then you conclude from analyzing the remaining small fraction of the data that the SLR data do not show a statistically significant acceleration in SLR.
You did throw out almost all the SLR data. That’s a fact. Did you conclude from analyzing the remaining small fraction of the SLR data that the SLR data do not show a statistically significant acceleration in SLR? Is that your conclusion, based on the data you analyzed?

crackers345
July 26, 2017 10:45 pm

willis, when you did a rank2 polynomial
fit, did
you multiply the quadratic coefficient
by 2 to get the acceleration?

crackers345
Reply to  Willis Eschenbach
July 26, 2017 11:51 pm

thanks; for some reason
that reply didn’t reach me;
or I
missed it. cheers willis.