Guest essay by Albert Parker
Just in case somebody could be interested in understanding if the climate scientists are telling us the truth about sea level acceleleration, there is still the opportunity to verify by using the tide gauge data in the PSMSL data base.
The tide gauges measure the relative sea level in many locations worldwide, mostly in northern Europe and North America, in the best cases since the mid-late 1800s, and are therefore the best source of information to understand what is going on…
The PSMSL data base include the time series of the monthly average mean sea levels recorded by every tide gauge…
· Go to http://www.psmsl.org/products/trends
· Use as start year 1900 and end year 1975 and then zoom and window over one selected area, for example Europe (but the United States and Canada or Australia and New Zealand work fine as well …)
· These were the relative sea level rates of rises about Europe in 1975 – this is a print screen of today 17 March 2016
· The above relative rates of rise are obtained by linearly fitting all the monthly average mean sea level data 1900 to 1975. The relative rate of rise is the slope of the fitting line.
· Now, let see what happened during the last 40 years …. Just move the end year to 2014 …
· These are the relative sea level rates of rises about Europe in 2014 – this is a print screen in March 2016
· The above relative rates of rise are obtained by linearly fitting all the monthly average mean sea level data 1900 to 2014.
· Surprise, surprise, no major changes …..
· Do you spot any significant change?
· Those that are claiming the sea levels are rising sharply than ever before at an accelerating rate are simply not telling the truth.
· This may realize (for now) downloading and analyzing the PSMSL data, or even analyzing the data online.
· In a few years’ time, also this data base will be corrupted and the truly measured data will be replaced by computations or reconstructions.
· Below same results for the US and Canada, plus Australia and New Zealand … just in case …
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So, tide gauges restricted almost entirely to N. Europe and USA coasts give us a reliable indication of GLOBAL sea level change do they?
How about using satellite-based instruments with global coverage instead?
“So, tide gauges restricted almost entirely to N. Europe and USA coasts give us a reliable indication of GLOBAL sea level change do they?”
It is more or less the same countries that express the most concern, so it is fair to look at the gauges in these countries.
I can recommend this site: http://www.psmsl.org/data/obtaining/
I don’t care if the oceans contain more or less water, but i care about the level at the shores, especially my shore. I live close to the shore in Danmark as most does, but think of the time involved. How many houses may be rebuild/mowed before it is a problem.
Plus, given the fact that there is no acceleration indicated, any rise that is happening has nothing to do with man made CO2 level increases. CAGW is unscientific , correction, anti- scientific nonsense. It belongs with voodoo, naturopathy, horoscopes, politics and other disreputable pursuits.
Bingo. Sure, there are places where sea level is rising faster than other places, but those are due to tectonic changes.
The sea level rise DOES impact these areas, but even if there was zero rise from warming, they would still be grappling with tectonic sea level rise. If warming did add another 1mm per year, its really irrelevant in the big picture.
I can’t think of any example of an area that would be fully able to adapt to natural sea level changes, but can’t adapt to fossil fueled changes of 1 mm per year.
Sea Level Controversy from Nature published paper that is ignored by IPCC cult of CAGW ‘scientists’.
Maximum mass and volume estimates from melting and expansion supports a sea level rise of 0.5 mm/yr not 3.0 mm/yr.
Note the Antarctic ice sheet is gaining mass not losing mass.
ftp://falcon.grdl.noaa.gov/pub/bob/2004nature.pdf
http://phys.org/news/2015-10-mass-gains-antarctic-ice-sheet.html
OH no, more dumb layman data analysis. Before I go into that here is what rigorous analysis of tide gauge data shows.
This if from Jevrejeva 2014. She does the usual genuflections to the orthodoxy by reporting that there is evidence of acceleration. She just avoids pointing out that NONE of the acceleration happens in the 20th c. let alone the part humans are allegedly responsible. But you have to read the paper, not just the abstract as Sturmbandfuehrer Cook would surely do.
I recommend actually reading the paper.
http://nora.nerc.ac.uk/504181/
As for what is wrong with Albert Parker’s effort: firstly, Since the mean trend is calculated for each period separately and subtracted, all this shows is that *distribution* of *relative* changes between these sites has not changes. It tells us nothing about the average trend itself which may be more or less but has been subtracted out , so it tells us nothing about it.
Secondly even if we did compare long term trends over different periods. this would not tell us whether there was any real acceleration anyway since like all the obsession with “trends” in climatology it depends upon the start and end dates chosen and tells us nothing objective.
As the Jevrejeva graph shows there is a substantial circa 60y variation so comparing a short and long period can show “acceleration” even on a non trending function like a cosine.
Anthony , I realise you don’t want to commit as much time as you used to to running WUWT but please vet submitted articles for common sense. The content of this site is taking a nose dive with some of “guest essays” that have been published recently. It used to be a reliable source of good information.
Greg, the problem with averaging sea levels at different sites is similar to measuring a global mean temperature anomaly. Without measurements spread out evenly where local land movement is small, the average is meaningless. Parker has done something similar to what I was about to do before finding out that the data has already been adjusted. Few examples of changes in the rate of uplift or subsidence occurring in the second half of the 20th C would occur so the majority of data sets should show a common change in rate of sea level rise.
I would have taken 30 year linear trends of all stations going back from the present for each station and plotted a histogram of the difference between the last 30 years and the prior 30 years. Its not just the average but since the majority of stations would not have had a change in the rate of uplift or subsidence, there should be a tell tale sharp peak if it were true. As Fort Denison 2 appears to have been adjusted, I didn’t bother checking the others for myself.
There are very few locations where geology is really stable. That is what Jevrejeva”s work tries to address. She does not give an open, reproducible account of her methods, only general description, so I can not validate here work and I am not aware of anyone who has done so. However, she does make a good effort at attacking the problem. I suggest you read the paper linked above.
Linear “trends” are meaningless in the presence of cyclic variability. If we banned the word from whole field of climatology we may start to make some progress.
If you took a 30y trend ending in 2005 and a 30y trend ending in 1975 you would presumably conclude “acceleration”. All these linear “trends” are a mugs game. Anyone can click “fit trend” in Excel. That is why it is so popular.
That gives the false impression that it mean something. It doesn’t.
Tide-gauge data is used to estimate change in sea level relative to land and most of Scandinavia has been rebounding upwards since the last glacial maximum, 20,000 or so years ago.
During many millennia, mantle rock in the lithosphere was displaced southwards by the weight of the huge Fenno-scandinavian glacier. This caused a forebulge some distance from the glacier.
Map: https://search.yahoo.com/search?
ei=utf-8&fr=tightropetb&p=Fennoscandinavian+glacier&type=12037_022616
As the mantle rock flows back north, the fore-bulge continues to subside causing a rise in relative sea level. Depending where you live in northern Europe glacial rebound in the lithosphere causes land along the coasts to rise in some places and to subside in other places.
(The same phenomenon is observed in North America where land subsidence occurs in places along the northeast coast as a result of subsidence of the forebulge.)
Paper: Holocene relative sea-level change, isostatic subsidence and the radial viscosity structure of the mantle of northwest Europe (Belgium, the Netherlands, Germany, southern North Sea)
http://www.sciencedirect.com/science/article/pii/S0277379107002053
Greg:
I was under the impression that Mr. Parker merely used the online trend program provided by the non-layman PSMSL.
While I’m on the subject, Jevrejeva 2014 also calculates simple linear trends (see Fig 7, for example).
However, I am less disturbed by linear fits to the remarkably steady sea level rise over the past century than I am by Jevrejeva demonstrating “acceleration” by second order polynomial fits to records anchored in the Little Ice Age (see her Fig 16). Good greif, talk about cherry picking!
Ktm
QUOTE
I can’t think of any example of an area that would be fully able to adapt to natural sea level changes, but can’t adapt to fossil fueled changes of 1 mm per year.
END QUOTE
To fix try: –
I can’t think of any example of an area that would be fully able to adapt to natural sea level changes, but can’t adapt to possible* fossil fuelled changes of 1 mm per year.
* possible, but not yet nailed down
Auto – not a model-worshipper.
I’m aware of the problems with fitting linear trends to data where its far from a nice linear trend with a little noise but with many stations, if acceleration was occurring then it would show up in a histogram. The average wouldn’t be meaningful.
For a host of technical reasons, satellites (TOPEX/Poseidon & Jason) are NOT capable of giving accurate sea level data (its only accurate to ±25mm),
Tide Gauge Data is accurate to ±3mm. http://tinyurl.com/pfgj8sm
Explanation of tide measurement problems – Failed Experiments in Measuring Global Sea Level Change. Willie Soon – Start at 15min http://tinyurl.com/k49aaja
Worth watching all of it.
Not so fast my friend. Even if the actual gauge Is accurate to +/- 3mm – and that’s not the kind of unit that was around decades ago, so comparisons to past levels of sea level reside are difficult – it doesn’t take account any changes in elevation to the unit itself.
Look into uplift and subsidence in coastal zones. For example http://www.ngs.noaa.gov/heightmod/NOAANOSNGSTR50.pdf
“…This study computed vertical velocities for over 2700 NGS benchmarks based on leveling
data collected between 1920 and 1995. Subsidence affects coastal areas of Louisiana,
Mississippi, Texas, and Alabama. The highest rates, over 25 mm per year, occur in the
Mississippi river delta region and chenier plain of southwest Louisiana…”
What good is a tide gauge accurate to +/- 3mm if it’s installation is changing up to 25 mm/yr in elevation?
Has anyone done a study on the relative sea level changes between hard rock and soft sediment coastal areas?
Soft sediment areas should show a much higher rate of change due to the effects of drawing down the water table for irrigation, industry and drinking purposes. In addition, recently deposited, soft sediment, areas are constantly compacting under their own weight, adding to the perceived rate of change in ocean levels.
It is not surprising therefore that Holland, Belgium and the Mississippi Delta Area are showing the highest rates of change.
The adjustments to the satellite altimetry data are greater than than the millimetres being measured, so it is important the the adjustments are based on accurate model of what how the satellite system is constructed, notably the optical path length (especially the drift in time) between the satellite and the surface, and the way to splice successive satellite data. Unfortunately there is insufficient agreement on the model. Envisat/Topix/Boulder/Portugal give different answers. With satellites they get good global coverage free from tectonic factors, but insufficient precision. Tide gauges give precision but cannot give global results because the land holding the gauge goes up and down by an insufficiently accurately known amount.
The satellite measurements are made from satellites in orbits 1336 kilometers above the oceans’ surfaces. The measurements are used to report annual changes in sea level to a precision of 0.1 millimeters, or one part in 13.36 billion. Arguably, since the measurements are based on the time for microwave signals to travel from the satellite to the ocean surface and return, 0.1 millimeter precision might actually represent one part in 26.72 billion, since the microwaves travel 26.72 billion millimeters from the satellite to the ocean surface and back to the satellite.
“The measurements are used to report annual changes in sea level to a precision of 0.1 millimeters, or one part in 13.36 billion.”
When I heard in the media that they would use satellite to measure see level, I thought it was either a joke or some misinterpretation by the journalist!
And people seem to accept that “science” is so great and miraculous and magical that this can be done.
Considering that the velocity of e-m waves depends somewhat on the density of the gas they are travelling through, and satellite orbits are perturbed by gravitation and solar wind, I find it hard to believe that distance measurements can be as accurate as that.
From electronics testbench experience, one of the problems of digital instrumentation is that the resolution of an instrument may be much greater than its inherent accuracy, and this may lead to undue faith being placed on the readout.
To pretend that you can work out mean level of an ocean with a swell of several metres by reflecting a beam of the BOTTOM of the swell and guessing magnitude of the swell is FARCICAL.
This uncertainty is not something which will average out globally because the same problem exists globally. It all depends on tuning of the highly complex process of converting distance to bottom of swell to mean sea height. In short you can produce whatever results you want.
And they do.
How the heck do satellite measurements of ocean levels adjust for the effects of all of the following:
1. Orbital eccentricity,
2, Orbital decay,
3. Tides,
4. Currents,
5. Waves,
6. Ocean temperature and
7. Atmospheric pressure systems?
Also, I remember reading somewhere that the findings are all subjected to classic alarmist homogenisation techniques in order to provide sufficiently scary results.
http://sealevel.colorado.edu/content/data-processing-methods
Wow! Talk about homogenisation on steroids.
Has anyone, without a pre-determined alarmist bias, professionally reviewed these to determine their validity?
Do satellites provide any usable information?
Supposedly. Hundreds of posts at this site base analyses of atmospheric temperature on satellite data. A lot of people here believe the satellite records for this metric are superior than the thermometer records. Atmospheric temperature is a more difficult metric to winnow than sea level. By that account, the answer to your question would be: depends who’s talking.
The no sarc answer is – yes, of course. Satellites are used for intercallibration with land measurements. No data set is perfect, but the more you have the more you can narrow things down. They also measure solar irradiance effectively, and can perform observational tasks of things above the clouds better than land-based instruments – less interference.
“Hundreds of posts at this site base analyses of atmospheric temperature on satellite data.”
So???
I guess that you are one of the “polio was eradicated by a vaccine so you must get the flu shot” guy. You must be for or against vaccines!
“A lot of people here believe the satellite records for this metric are superior than the thermometer records”
Nobody here believe that satellite can sense your living room better than thermometer. The local station is the best place to measure local conditions. Global warming isn’t about the temperature in the living room. Sea level rise will flood Manhattan isn’t about the energy content of the Atlantic ocean.
“Atmospheric temperature is a more difficult metric to winnow than sea level. ”
I don’t understand.
“The no sarc answer is”
So now you are saying all the above was sarc and you didn’t mean it?
“Satellites are used for intercallibration with land measurements. No data set is perfect, but the more you have the more you can narrow things down”
So because temp satellite provide better information, we should trust other satellites that don’t even agree with each other? And how do we know which “adjustment” is valid?
There are so many unknowns…
“Atmospheric temperature is a more difficult metric to winnow than sea level. ”
I don’t understand.
Lower atmospheric temperatures are derived from radiance measurements of O2 from several different channels representing different slabs of the atmosphere, each many kilometers in depth. It’s a proxy measurement of temperature that has to derive temperature of a slab of the lower atmosphere by combining/subtracting other channels that measure well up into the stratosphere. Sea level measurements are directly measured from sea surface (infrared bounce) with a height window of a few meters (tide/swell). The processing steps for temps are more numerous and more onerous than for sea level height with respect to satellites, with an altitude difference of several orders of magnitude.
Both metrics have challenges in common, too, like satellite drift, orbital decay etc.
So because temp satellite provide better information, we should trust other satellites that don’t even agree with each other? And how do we know which “adjustment” is valid?
Satellites provide better coverage. We should not automatically defer to any one set of measurements, but calibrate against each other to narrow uncertainties. That’s why more data sets are useful. That’s why satellites are useful. They are an additional – not replacement – observation set.
Tide gauge records go back to 1850, long before anyone thought about global warming, realistically one measurement from one place would give a good indication, when you go to a clinic they measure you temperature at one ear, not all over your body.
None of the satellites show the same level, they have to be adjusted to show the same, and they have algorithms based on tide gauge levels.
Me I believe the tide gauges thank you.
Indeed, the tide gauges averaged over the globe give a solid reality check on the modern Sea level change and rate blurb. If you go back to the 1992 IPCC ‘report’ scare-campaign to governments and institutions, they made a big deal about two things, temps and sea level change, in 30 and 100 years forwards of 1992, and the rates of change predicted were frankly small and ordinary.
At the time I remember thinking is this what they’re worried about? There are higher known rates from natural regional (ice loads changing on land leading to relative isostatic change) and also global change. The figures were about what you’d expect from background natural variability, due geodynamic movement and climate variability. But they made it sound like a new global ’emergency’ was pending. I would have been surprised if such changes didn’t eventuate, both regionally and globally, in 30 and 100 years, from natural variability alone.
Nevertheless, an average of the available raw continuous tidal measurements in harbors globally does undercut and negate theoretically fanciful, or else satellite based claims. Precision of satellites does not mean much if it is not calibrated to the real world ground measurements. Otherwise you get error presented as signal. Satellite data is and always must be ‘ground-truthed’ against the actual surface measurement, otherwise the data has no reality or validity. So ground-truthing of geodetic satellites in this case is historical tidal data and VLBI site vertical movements in a region (both of which are spotty but there are enough to obtain a global average vertical movement in the +/- 1 mm level annually).
If the satellite data does not match the tide data, then it’s the satellite that is reading the tide, or rather local sea level change rate, wrongly.
Not the other way around.
If however, the global tide range varied little or not at all, but the VLBI and Topex datasets varied vertically by a much larger positive amount, even after they were calibrated properly, it would mean the Earth’s diameter was increasing, by several mm per year, not merely a relative sea level change with respect to land. In other words, the interpretation of the signal would be what’s wrong, not the data sets. So if tide gauges largely don’t change, but calibrated satellites say sea level is going up much faster than tides capture, then the earth would have to be increasing in size due to internal changes or cycles.
So is that what their sea level change data is really capturing? A global diameter change? If the tidal data says there is no significant tide level change, that would be the implication of the satellite signals.
Warmer-worriers will of course try to retrospectively rig the tide data, but if they can’t, they must downplay its relevance and disparage its accuracy and try to ignore it in favor satellites and their creative-fiction predictive change models that pretend to be the real world measure of the planet, and that the actual measurements no longer matter.
But the tidal gauges always matter, and they will always trump every other form of sea level measurement.
However, also keep in mind that in recent decades many harbors have had a lot of development springing up in, on and around them and the weight placed upon unconsolidated muds, clay and sand also makes surrounding fixed installations slowly begin to sink into the sediment and the local crust to slightly depress, which probably accounts for much of the ‘rise signal’ in modernized old harbors with many of these gauges anyway. It certainly will apply to the USA, Australia and Many European harbor gauges.
So a simplistic presumption can not be made that apparent sea level change is actually due to a thermal change of water, combined with melt water. It ain’t necessarily so, and a rise signal in a port may simply be sediment and structure settlement.
Venice and Mississippi delta area, plus coastal Bangladesh, even Jakarta and Tokyo are examples of subsidence, due to the weight change of construction, or younger sediment deposition at high rates pushing crust down, tectonic crustal down-warp, plus aquifer extractions, etc.
All is not actual sea level change. And only a relative comparisons plus an average global movement of sea level from tide gauges, can provide the reality checking needed here.
Few years back at TROPMET symposium, former Dyputy Director General of Forecasting [DDGF], Dr. P. K. Das [after retirement working in the West] was felicitated for his great achievements. He presented a big speech after the falicitation. I asked him a simple question, do our seas are rising or falling. He replied back saying, we have 12 tode gauges along our coasts and of them 4 show a fall and 8 showed no change — I quoted in my research papers & books a decade back. Later group working for IPCC reports changed this and tried to say sea level is rising. Along the Indian coasts, against CRZ rules, developmental activities destroyed the coast, Mangroves, considered as protective walls from tidal fury associated with cyclonic activity. Drilling for Oil & gas also creating subsidence in the Earth along the coasts.
Dr. S. Jeevananda Reddy
Every scientific assertion in the IPCC reports is incorrect. The assertion that ocean level rise is accelerating is only of many assertions which are obviously not supported by the data.
http://scienceandpublicpolicy.org/images/stories/papers/reprint/sea_level_not_rising.pdf
http://www.21stcenturysciencetech.com/Articles_2011/Winter-2010/Morner.pdf
“Every scientific assertion in the IPCC reports is incorrect.”
Well, at least they’re consistent…
[IPCC] – The assertion that ocean level rise is accelerating is only of many assertions…
IPCC say it is “likely” (66-100% probability) sea level rise has accelerated since 1900.
barry,
The IPCC simply does not know. Measuring MSL is notoriously difficult. The best SL measurements come from numerous tide gauges. When dozens of tide gauges are averaged, from all points around the globe, they show nothing unusual is happening. But the IPCC says it’s ‘likely’ that the long term, natural rise in sea levels is accelerating. They are paid to say that.
It’s astonishing how easily some folks just fall to their knees and begin worshiping government agencies. Have you no self respect at all?
The only honest kind of scientists are skeptics. Only a fool would blindly accept the self-serving proclamations of the IPCC, or of any similar organization with the same kind of remit. Governments hired those scientists to produce a predetermined result, and that’s exactly what the IPCC is doing. What possible reason could you have for defending that kind of scam on the public?
No argument from me that sea level acceleration is difficult and uncertain. Just pointing out that IPCC do not flat-out claim it is definite since 1900 (ie, not an ‘assertion’). I don’t think it’s well-established either. I’ve read a lot about it, though I’m no expert of course. I don’t make the common mistake of favouring one or two studies that present one side of the argument… the ol’ single-study syndrome and its derivatives.
What nonsense is that, Bill H. — Sea levels ARE truly global. Water is always level, see !!! It finds its own, accurate height automatically – as you must have learnt at primary school, Bill H.
“Water is always level, see”
No.
It’s a little more complicated in a dynamic system.
Actually, the Pacific side of the Panama isthmus is 20cm higher than the Atlantic side.
https://answers.yahoo.com/question/index?qid=20080127094848AAebPlT
The equator is 21 kms higher than the poles due to the centrifugal force of rotation. The land masses have more gravity and thus pull some of the ocean toward them. Sea level can fall or rise by 10 mms depending on whether it is warmer or colder than normal. Some areas of the planet have more gravity and thus sea level is lower etc.
These are all big problems for a satellite measuring sea level from 1336 km orbits.
The idealized geoid accounts for the flattening at the poles and other more or less regular variations in the Earth’s surface. Therefore the surface of the world ocean fits closely the shape of the ideal geoid.
But not exactly. Because the elevation of the ocean’s surface is affected by gravity. And there re irregular dimples and bulges where gravity is greater or less than average for the globe.
For example, the Maldives are located in a “gravity well” about 200-meters lower than the “surface” of the geoid. This gravity well is a more or less permanent dimple in the real surface caused by a gravitational anomaly.
The idealized geoid does not fit exactly the shape of the real Earth. This is one reason most GPS units do not measure elevation accurately, but instead display what elevation would be if the surface of land or water corresponded to the ideal geoid. To measure elevation a nd location precisely, including tectonics, special techniques are used, including reference stations.
In my opinion, tide gauge elevations should be adjusted for vertical land movement caused by plate tectonics as well as other causes of land uplift and subsidence.
No they aren’t truly global. Many things effect the level of water including the mass of the earth in the particular location. Nice informative video here on the basics of what “sea level” actually is. https://www.youtube.com/watch?v=q65O3qA0-n4
Besides the effect of gravity there is also the effect of the differences in atmospheric pressure. Perhaps the most obviouse example of this is the mound of water that rises under the very low pressures found in tropical cyclones/hurricanes and which are a major factor in causing storm surge when such storms come ashore.
Yes, I know of course that actual levels vary all over the world for all sort of reasons. That is all implied by talking about “eustatic sea level”. That is the level which is global at all times. That is what we are talking about here – not nit-picking about various local differences.
I’ll let you supply the satellite data for the year 1900.
for sure tides gauges don’t measure sea level , but satellites measurements are not direct, they must be checked or cross validated… if some claims are made that sea live rise accelerates you can expect to see an acceleration in tide gauge measurments too… I know it is quite complicated because for instance thermal expansion, but….you only have one set of measurement of sea level…it must be validated.
Bill H March 19, 2016 at 3:18 pm said:
…How about using satellite-based instruments with global coverage instead?
Satellite data would be great if the data would only hold still:
http://oi58.tinypic.com/331k5ya.jpg
Since 2004 the Colorado University’s Sea Level Research Group has adjusted the rate of sea level rise upwards by almost a full millimeter per year.
Didn’t they stop measuring ‘actual’ sea level, and switched to a WAG of what it would be if the land under the ocean wasn’t sinking due to the additional weight of the water due to sea level rising.
Didn’t they stop measuring ‘actual’ sea level, and switched to a WAG of what it would be if the land under the ocean wasn’t sinking due to the additional weight of the water due to sea level rising.
Kinda. They now measure sea level as a function of volume. Isostatic rebound is still occurring from the last ice age, as land upwells and ocean basins deepen from the loss of the great ice sheets of that period. This has a negative effect on mean sea level height. They adjust for that at +0.3mm/yr. The reason they do this is in order to estimate global climatic changes, rather than just averaged sea level height. It’s a simple matter of subtracting 0.3mm for geodetic sea level if that’s the metric wanted. For local sea level, other factors come into play (local and regional land rise/subsistence).
Hello Steve. Hope you’re well, my old sparrer.
The GIA adjustment, which they started applying a few years back, accounts for some of the difference in your chart. It’s difficult to make out the chart is representing, though. The chart title is sea level 2004 to 2014. But the X axis starts 1994 and stops at 2004 (?). The rel1, rel1.2 don’t refer to different methodologies as far as I can tell. That’s the shortened form of the language they use for each of the data updates they do a few times a year (2004: Release 1, Release 2… 2005, Release 1, Release 2…. 2010 Release 1, Release 2 etc).
I trust we don’t have to traipse through the criticism of data improvements routine. Everyone does it (UAH, RSS etc). Data revision is an everyday fact and good practice. If the question “is the data perfect?” is never asked and acted on, that would be supremely sloppy science.
It’s worth pointing out that there are several other institutes processing the satellite data that come up with very similar results to CU. NOAA provide sea level estimate from satellites without GIA factored and get 2.9mm/yr +/- 0.4.
http://www.star.nesdis.noaa.gov/sod/lsa/SeaLevelRise/
Bill, there are tide gauges in the SH, such as in Sydney and Auckland, that have over 100 years of data and also show no increase in the rate of SLR. The problem with tide gauges for the alarmist camp is that they are an exact measurement and therefore cannot be adjusted in the same manner as the satellite data, which is really only an artifact of adjustments in any case.
And Cape Town.
Tide gauge measurements may be adjusted depending on the purpose. Tide gauges only measure local sea level change referenced to the gauge. If the gauge itself is on land that is rising or falling, then it’s not a measure of geodetic sea level change over time.
Say you want to know if global averaged sea level is changing. You know that tide gauges are not altitude static, that tide gauges are not geospatially equidistant, and that you can’t assume local land altitude changes cancel each other out. How would you go about estimating a global average?
barry says:
… you can’t assume local land altitude changes cancel each other out.
You can if you have enough of them. With a few hundred tide gauges around the globe, some would be reporting subsidence, and some would show uplift. Averaging all of them would work because on average, the earth’s land areas cannot show a net rising or subsidence. If that happened the globe would either become bigger, or smaller. That is very easy to determine, and in fact, the globe’s diameter remains stable.
Thus, a large enough tide gauge network would show what MSL is actually doing.
But don’t wait for the UN/IPCC to spend the little money it would take to construct several hundred more tide gauges. That would show what the sea level is actually doing. They do not want that, because they know it’s very likely that there is no acceleration in MSL. So they will continue to publish their pseudo-science in hopes of scaring the public.
There is no reason to assume biases would cancel each other out. Tide gauge data is sparse, especially prior to 1950 – there are not ‘hundreds’ that stretch from 1900, not even one hundred. And they are not evenly distributed around the globe. Long-term records are concentrated in Northern US and Northern Europe, where rebound from the last ice age is lifting the land. There’s barely a handful in the Southern hemisphere with long records. But I wouldn’t assume anything about overall bias from that. Detailed analysis needs to be done.
Assuming data is perfect, or that biases would cancel out without actually checking would be very sloppy research.
barry,
Maybe I wasn’t clear enough. I’ll try again.
The UN/IPCC has an enormous budget. For only a modest expense, it could establish tide gauges in hundreds of locations covering the globe.
The readings would average out subsidence and uplift, leaving the true ∆MSL.
But they won’t do that, for the reasons I gave. They do not want an accurate reading of change in sea level. I think it would show that their remit is entirely political, covered with a thin veneer of science so the3y can sell their alarmism to the public.
So measuring the rate of filling of water at one end of the bath gives us a reliable indication of the rate of increase of the depth of water at the other?
Bah ! Humbug!
For a bath? Well, yes, if you know the dimensions of the bath, or even if you know the dimensions of the bath above the waterline at some point in the filling.
Quite a bit more complicated for the bath the continents are wallowing in, though!
We use one CO2 measurement from one location to give us the GLOBAL CO2 content of the atmosphere.
Well, it makes sense to measure SLR at the coast, rather than at the middle of the ocean. Satellites aren’t interested in the coasts.
Bill,
Satellite data only goes to 1979. To see if there is an acceleration, you need older data. If sea levels aren’t rising at the same rate everywhere (all continents share the same oceans) then you have to see what the LAND is doing. Land movement, up or down, is NOT considered part of sea levels rising.
No real news here, but a nice way to present things, and alerting people to PSMSL availability is a real plus!!!
In areas that have remained tectonically inert, neither sinking nor uplifting since the middle 1800s, while CO2 has shown a 40% increase, the inert zones clearly show an unchanging linear rise of about 1.2mm/yr.
No acceleration in the rate of sea-level rise whatsoever. (repeat the last sentence 3X!!!). For isostatic background, etc., if you have a chunk of time available, check out the first 30 minutes of this January 26, 2016 National Press Club presentation – the whole event runs 2hrs + with Q&A:
Thanks for that extremely lucid presentation, maybe the best I have seen on sea-level rise. I would send it around, but I found the talk by the Larouche woman, setting up the totalitarian Red Chinese government as some kind of utopian ideal, fanciful and even offensive. Though she did seem to agree that the ‘green revolution’ of the ’60s and ’70s was anti-progress, anti-intellectual, and anti-human, which is true, a point which should be made more often.
/Mr Lynn
But the UK Met Office says it is.
“How about using satellite-based instruments with global coverage instead?”
Because the coasts are all that matter to folk that live on land?
Different folk have different interests. If you want to answer questions on a global scale, reading your local tide gauge isn’t going to tell you anything.
Um, the two maps of Australia look the same ‘cos they are the same…
The linked site contains this caveat:
“Note that these measured trends are not corrected for local land movement. Furthermore, no attempt has been made to assess the validity of any individual fit, so results should not be treated as a publication quality values suitable for use in planning or policy making.”
Tide guages have two problems. One is isotatic rebound from the last glaciation. Visible along western Europe and NA east coasy. Two is tectonics, very visible along PNW north America (especially Alaska). Both are correctile by finding the long term tide guage subset that is reasonably geostationary. That can be done using differential GPS over some years. Answer is about 1.8-2.0 mm/ yr rise measurement/ geostationary uncertainty), and no SLR acceleration in the last 45.
Interestingly, this number does not give rise to the so called divergence problem. The sat altimetry valuess do. Suggests the sat altimetry has reasonable precision but not reasonable accuracy. Especially since explicitly not measuring shorelines.
If the concern is that a warming planet will flood coastal areas, then it is IMPROPER to subtract out the isostatic rebound.
If the lands is rebounding and making floods less likely, GREAT. What really matters is the sea level measured at the coast, not the volume of the ocean.
If I have purchased property in Nova Scotia based on the idea that the AGW’ers tell me it will be oceanfront next week; who do I sue now that the ocean is farther away?
“If the concern is that a warming planet will flood coastal areas”
Yes and no. The concern is future flooding caused by sea warming, not present flooding.
“then it is IMPROPER to subtract out the isostatic rebound.”
Present sea level is a proxy for present sea warming. It is proper to subtract coast change.
Present sea warming is used to check models used for future sea warming. Absolute sea level is relevant.
What is the optimal ocean volume?
It’s an absurd question, yet some seem to think that the change in ocean volume is the key concern. It just isn’t.
The sea level gauge at The Battery New York has shown a straight line increase since Lincoln was president. Today’s sea level is no more good or bad or right or wrong than it was in 1850.
Even if there is a small component related to warming, it is dwarfed by the natural changes. At least in new York city, which is often cited as a place where sea level rise from climate change could have major impacts, the tide gauge record shows that it truly is irrelevant.
gauge
According to the IPCC (2013), sea levels rose at a rate of 1.7 mm/year (6.7 inches per century) for the 1901 to 2010 period, but 3.2 mm/year (12.6 inches per century) during the 18-year period between 1993 to 2010, a rate similar to that obtained from 1920 to 1950.
—
http://www.climatechange2013.org/images/report/WG1AR5_Chapter13_FINAL.pdf
“It is very likely that the global mean rate was 1.7 mm yr–1 between 1901 and 2010 for a total sea level rise of 0.19 m. Between 1993 and 2010, the rate was very likely higher at 3.2 mm yr–1; similarly high rates likely occurred between 1920 and 1950.”
—
Problematically, in recent decades the source contribution estimates for recent decades from published studies add up to half (or less) of this claimed rate for 1993 to 2010.
According to recent estimates, the contribution to sea level rise from thermal expansion was 0.64 mm/yr (2.5 inches per century) for the period between 2005-2013 (Llovel et al., 2014, see below). The contribution from the Greenland (GIS) and Antarctic (AIS) ice sheets was 0.59 mm/yr (2.3 inches per century) for the 1992-2011 period (Shepherd et al., 2012). The contribution from global glaciers and ice caps that are not the GIS or AIS was 0.41 mm/yr (1.6 inches per century) for 2003-2010 (Jacob et al., 2012).
—
Llovel et al., 2014
http://www.nature.com/nclimate/journal/v4/n11/full/nclimate2387.html
Over the entire water column, independent estimates of ocean warming yield a contribution of 0.77 ± 0.28 mm yr−1 in sea-level rise … the deep ocean (below 2,000 m) contributes −0.13 ± 0.72 mm yr−1 to global sea-level rise [0.64 mm/yr total].
—
Shepherd et al., 2012
http://science.sciencemag.org/content/338/6111/1183
Since 1992, the polar ice sheets [Antarctica and Greenland] have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.
—
Jacob et al., 2012
http://www.nature.com/nature/journal/v482/n7386/abs/nature10847.html
Here we show that GICs [glaciers and ice caps], excluding the Greenland and Antarctic peripheral GICs, lost mass at a rate of 148 ± 30 Gt yr−1 from January 2003 to December 2010, contributing 0.41 ± 0.08 mm yr−1 to sea level rise.
—
These sources add up to about 1.6 mm/year, which is the equivalent of a little over 6 inches per century. Interestingly, this is the same or slightly less than the rate for the entire 1901 to 2010 period (1.7 mm/year, IPCC), meaning that sea level rise has not accelerated in recent decades according to the summation of source estimates.
Additionally, if we include the Zwally et al., 2015 paper, which indicated that net gains for Antarctica negatively contributed to sea level by -0.28 mm/year between 1992-2008, sea level rise contributions drop down to 1.3 mm/year, or 5 inches per century in recent years.
Newport, RI yearly avg, 1900-2014
http://www.psmsl.org/data/obtaining/rlr.annual.plots/351_high.png
Wasn’t there a paper in the Journal of Geophysics – Oceans in August 2010 with the same conclusion – no acceleration of sea level rise in the past 100+ years?
Looks like the Climate “Change Scientists”, if we can call them that, are again caught red handed!
Ha ha
Yes. It was politically rejected. So sad.
The only changes I noticed between the sets of tide guage maps was that the Canadians had a new one on their west coast.
“In a few years’ time, also this data base will be corrupted and the truly measured data will be replaced by computations or reconstructions.”
============
Which will lead to another “pause” when the fudged data comes more into line with measurements.
Talk about tangled webs.
MASS HALLUCINATIONS ACROSS EUROPE
February 7th, 2025
Scientists today are reporting on one of the most intriguing cases of a shared hallucination to have ever been recorded., All across Britain and Northern Europe peole have woken up to find they have been hallucinating ‘snow’ – and apparently its feels just like the ‘real thing’. as Mrs Crombie from Abergavenny says , ‘I opened my door and there it was, snow, just like I remembered it’.
However climate scientists have reassured the public,that it isn’t snow, it’s just a group hallucination: ‘It’s basic philosophy of science’, said Professors Green, ‘Occam’s Razor is the principle. For it actually to be snow we would have to rewrite the whole science of climate, and invalidate years and billions of research, Occam’s razor says that the far more simple explanation is a simple shared hallucination’.
A Mr Monckton, of Brenchley, in his dotage was heard to mutter “Eppur sta nevicando” before he was put in an ambulance and taken back to his re-education centre.
Scientists have said that this sort of hallucination is what happens when people listen to ‘deniers’ and is further proof that anyone in a liberal tolerant society should maintain an extreme level of vigilance and intolerance towards anyone who challenges Accepted Science.
‘Otherwise who knows where we would be, if we just relied on so-called ‘common sense’, and our subjective experience, to tell us what is going on’.
Looks like the Climate “Change Scientists” have been caught red handed again!
Ha ha
Why compare 1900-1975 with 1900-2014, rather than with 1975-2014?
That would highlight the acceleration better.
Exactly so, by compare 1900-1975 with 1900-2014 the accelerated rate of rise over the more recent decades is diluted into the earlier longer period. Comparing 1900-1975 with 1975-2014 Does show a faster rate of rise in the second period.
I’m left wondering why Albert Parker chose to do the comparison in the was he did.
– In the Maldives, a group of Australian environmental
scientistscriminals uprooted a 50-year-old tree by theshoreline, aiming to conceal the fact that its location indicated that sea level had not been rising.
Scientists pursue the truth, even inconvenient to their favored hypothesis.
Criminals conceal evidence that could endanger their livlihood.
So what’s the global average using the tidal gauges? Is it more than 5-7 increase in inches by 2100 if it continues as is? I didn’t see that in the article. I didn’t see Nils Axel Morner (sea level data expert) quoted in the article. Maybe I missed it…Isn’t it data that we want, rather than models?
I have always wondered about ocean currents and their drivers, and what the effects are on local sea levels. Any ideas?
There is an opportunity here for climate watchers to take snapshots of the entire raw data sets and put them in independent long term archives. It would be proof against the type of editing and adjustment of the past which trashed the surface temperature records.
For example, people go on and on about the pause/not pause, and it was warmer/not warmer than 1998. but people seldom look back further. The way the period 1900-1975 was portrayed in 1980 is totally different from the way it is portrayed today.
Independent archives of the raw data would put a stop to a lot of that nonsense.
See also the results of the SEAFRAME gages.
Ian
Since I live on the coast and I think the sea level rise bed-wetters are a bunch of liars, I prefer to just go and look at it to know what’s going on.
Me too here in Cape Town Phil; nothing changed in 60 years. These guys think we are dupes.
One well documented benchmark shows about 4 inch increase since it was placed in 1841
Location in a geologically stable area.
http://www.john-daly.com/deadisle/index.htm
Photos of the Statue of Liberty construction on Bedlow’s Island show no change in sea level since 1880s by direct observation.
Photos of sea level at the Brooklyn bridge towers in 1880s show no change in sea level since then.
“In a few years’ time, also this data base will be corrupted and the truly measured data will be replaced by computations or reconstructions.”
we landed on the moon
Even though satellite sea level data has been manipulated over the years
http://oi58.tinypic.com/331k5ya.jpg
it does provide useful information. The changes mostly affect the slope of the graph, so it’s possible to plot out the changes to the overall rate over time:
http://oi63.tinypic.com/2vinjnd.jpg
Regarding the 2nd chart it’s a question of whether or not the uptick since 2012 is going to continue or not.
Just ten years were plotted out because the earlier and shorter time spans are distorted by short term variations.
Link to the data:
http://sealevel.colorado.edu/files/2016_rel1/sl_ns_global.txt
Looks like very noisy data with changes of 6 mm in a month
Steve Case:
Was there a single correction that accounts for all/most of the recent acceleration or was it a Karl-esque multi-stage rocket process?
And what about the tectonic moves on the deep bottom of the seas?
Let’s imagine a long range of underwater volcanoes beginning erupting and spitting huge volumes of lavas on their slopes or whatever uprising of the bottom. An uprising of one meter of the bottom on millions square kilometers for one century may bring a consequent uprising of the sea levels too.
Will the oceanographers be able to notice when a 4302 meters depth became 4301 instead in the same place half a century later? I don’t think so.