From the UNIVERSITY OF HAWAII AT MANOA
Historical records may underestimate global sea level rise
New research published in Geophysical Research Letters shows that the longest and highest-quality records of historical ocean water levels may underestimate the amount of global average sea level rise that occurred during the 20th century. Dr. Philip Thompson, associate director of the University of Hawai’i Sea Level Center in the School of Ocean and Earth Science and Technology (SOEST), led the study.
“It’s not that there’s something wrong with the instruments or the data,” said Thompson, “but for a variety of reasons, sea level does not change at the same pace everywhere at the same time. As it turns out, our best historical sea level records tend to be located where past sea level rise was most likely less than the true global average.”
A team of earth scientists from the University of Hawai’i at Mānoa, Old Dominion University, and the NASA Jet Propulsion Laboratory worked together to evaluate how various processes that cause sea level to change differently in different places may have affected past measurements. One particularly important concept is the existence of “ice melt fingerprints”, which are global patterns of sea level change caused by deviations in Earth’s rotation and local gravity that occur when a large ice mass melts. Each glacier, ice cap, or ice sheet has a unique melt fingerprint that can be determined using NASA’s GRACE satellite measurements of Earth’s changing gravitational field.
During the 20th century, the dominant sources of global ice melt were in the Northern Hemisphere. The results of this study showed that many of the highest-quality historical water level records are taken from places where the melt fingerprints of Northern Hemisphere sources result in reduced local sea level change compared to the global average. Furthermore, the scientists found that factors capable of enhancing sea level rise at these locations, such as wind or Southern Hemisphere melt, were not likely to have counteracted the impact of fingerprints from Northern Hemisphere ice melt.
“This is really important, because it is possible that certain melt fingerprints or the influence of wind on ocean circulation might cause us to overestimate past sea level rise,” said Thompson, “but these results suggest that is not likely and allow us to establish the minimum amount of global sea level rose that could have occurred during the last century.”
The investigation concludes that it is highly unlikely that global average sea level rose less than 14 centimeters during the 20th century, while the most likely amount was closer to 17 centimeters.
The full paper can be found here, and more information about sea level change can be found on the University of Hawai’i Sea Level Center website and the NASA sea level change website.
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So, an extra 3 cm. Is this any bg deal, especially when a realistic margin of error is added to measurements which are instrinsically very difficult to perform accurately.
Big deal or not, they’re likely to use this as an excuse to adjust sea-level measurements higher and then claim there’s been an unprecedented acceleration in sea-level rise.
I’d like to see Dr Philip Thompson’s inverted barometer correction going back to the beginning of the 20th century.
Then we can start talking.
It’s funny how, according to GRACE, the water always piles up in the middle of the ocean where there are no tide gages.
May, Could, Might, Likely, Unlikely, Possibly, If, But, Blah, Blah, Blah
As I said before, “It’s wurst that we thought.” The stuff that goes into the sausage making of the Eschatological Cargo Cult of the CAGW is nothing that you want to learn about.
How do you misunderestimate something that you already know exactly what happened.
It’s the future that we most often misunderestimate.
g
Is “misunderestimate” a generalization for both “over underestimate” and “under estimate” while excluding “exactly underestimate?”
And in a few more years they will discover that we have been wrong about hydrostatics and that in fact water runs up hill. More not likelys and coulds. Must be grant time.
As was mentioned in “Cadillac Desert”, “In California, water runs uphill – towards money.”
Boy, they can’t get anything right, can they? And always worse than they thought.
Seems to be turning out that they themselves are worse than what WE thought they were.
Yeah. And I thought they were pretty bad.
Gotta get it right Joel. It’s not sea level rise that is wurster, it’s THEIR estimates of what it was that wer wurster.
Capiche ?
At my age I’m shrinking faster than SLR.
Which begs the question, why should we listen to them THIS time?
Ah Joel, if the report said “No sea level,” raise” no more money!
So if it rose less than we thought in the past it must be worse now.. LMAO and how do we make a fluid body rise in one spot and not distribute evenly. It would seem we are defying the laws of nature now.
Prof Humlum explains it at the excellent Climate4you website:
“Temperature-driven ocean water expansion will therefore not in itself lead to lateral displacement of water, but only lift the ocean surface locally. Near the coast, where people are living, the depth of water approaches zero, so no temperature-driven expansion will take place here (Mörner 2015). Mechanism 3 is for that reason not important for coastal regions …”.
The sea level change in the middle of oceans could be due to thermal expansion while that around Greenland may be due to deglaciation.
That’s in addition to change due to glacier melt of course.
Baloney ! at the coast the water level REACHES zero, and most people live on the dry side of the water, and not the wet side.
g
Call the Guiness Book of World Records! This is the stupidest answer ever given! The middle of the ocean expands its depth and that has no effect at the coasts? Ridiculous!
I dont buy that argument. The surface of the oceans must be in level perpendicular to the gravity.
The gravity changes hardly by some warmer water, so the mid ocean expanded water flows out and also into the coasts. I wonder how Mörner could come up with that idea.
It IS worse now – not the Sea-Level, but its reporting!
In tectonically inert areas, which neither subside or experience uplift, SLR hovers around the 12cm per century range, and now that Antarctica is gaining snow and ice that reduces SLR by 0.23mm per year (see Zwally, Li et al Journal of Glaciology, Vol. 61, No. 230, 2015), the net rise is subject to further reduction, as opposed to increase.
Svend wrote, “The surface of the oceans must be in level perpendicular to the gravity,” and George wrote, “They’re right at sea level. How could they be taller?”
Gravity balances mass, not volume. So, when a section of the open ocean expands due to temperature change, the water does not “run downhill” to another, cooler, part of the ocean. Rather, it bulges up, in place. The most dramatic example is ice:
http://burtonsys.com/climate/iceberg_1521870c_annotated.jpg
The displacement of that ice is exactly the same when it melts. No lateral water flows result, and sea-level is not affected elsewhere (other than through an insignificant effect on salinity).
Here’s some more information:
http://www.sealevel.info/resources.html#steric
how do we make a fluid body rise in one spot and not distribute evenly
http://image.made-in-china.com/2f0j00KeNTPWQnZhku/Water-Slide-Hill-Side-WS-038-.jpg
Happens all the time. That’s how the satellites spot great pools of warm water. They’re “taller” than the surrounding waters.
They’re right at sea level. How could they be taller ??
g
“They’re right at sea level. How could they be taller ??”
It is a mistake to think the sea is flat. The sea is about 13 miles higher at the equator than the poles, for instance. Sea level rise varies with position, as well. That is how the average sea level can increase but nowhere becomes flooded.
Fluid in a rest state will displace laterally in a container. The rub is that the ocean is not a giant glass of room temperature water. Lots of different external forces are acting on it constantly–it’s never in a rest state.
Didn’t one researcher statistically prove that elevators go up 67% of the time?
No it’s 57% one for each State of the USA, and one for each gender not counting hermaphrodites.
g
Wait until they figure out that it is just like the Gilligan’s Island episode where Gilligan’s kept moving the professor’s gauge stick
+++ i remember that one:-)
I spent some time at sea,
Can’t wait for UAH and RSS to take their 1979-onward satellite data and use it for 1879-1978 conclusions about temperature trends.
One bright day in the middle of the night,
Two dead men got up to fight.
Back to back they faced each other,
Drew their swords and shot each other.
If you don’t believe the story’s true
Ask the blind man, he saw it too!
At the risk of boring people (sorry), I’m reminded of my dear departed Mother’s variation – perhaps predated to the 19th Century!?! An unexpected summary of the CAGW phenomenon:
One dark night in the middle of the day
A fire broke out in the ocean.
A blind man saw it.
A deaf man heard it.
A man with no legs, ran to fetch the engine.
The engine came with two dead horses, ran over two dead cats and half killed them!
With the NOAA sea level rise maps showing worldwide variations in SLR, almost everywhere has subsidence or rise. How does one tell the difference, and sort out true SLR?
In real science, sea level is either regional or eustatic (globally apparent sea level change). Eustatic sea level change is when ALL (or at least all but the extreme exception) regional sea levels are all rising or falling, i.e. end of last glacial period. Otherwise, it is said that sea level is at stand still. The important thing to remember in this is that sea level is actually just a relative term, as the shifting of sediments and changes in ocean floor bathymetry are constantly changing the volume of the Earth’s basins — sometimes significant enough to cause eustatic change themselves.
In pseudoscience, sea level is imagined as a quantitative measurement entirely due to the crysosphere, and the number given is derived by statistics and then said to be rising or falling compared to an arbitrarily chosen 19th century average. From that single basic misunderstanding and ignorance, there you have it, one branch of climastrology.
You don’t. It’s like global average temperature, a figment of academia.
Isn’t this a variation of trying to rationalize why the actual data is not as high as you hoped it would be?
Will they now “adjust” the data to meet their expectations?
Special offer for climate scientisits : Cherry picker for sale.
wait a minute…I’m in the market for a good cherry picker – I’ve loads of trees that need pruning! A good cherry picker would be very handy.
As I was saying…. I spent some time at sea. Well actually I spent a lot of time at sea. To tell the truth I spent most of my working life at sea. The thing is this. A ship at sea, will develop an easy rolling action, and an easy pitching action. So in fact the ship sort of corkscrews. And of course everyone in the ship knows all about this and lives with it, easily and comfortably. Whether it is walking along a long, long deck, where the ship can be seen to be flexing longitudinally as well as corkscrewing, or eating the very fine soup they serve in ships, or sleeping soundly in a bed which is always arranged in a fore & aft position. But wherever, or whenever, we always experience sudden, unexpected jerks (even of mighty vessels) or shakings, or bl**dy great bangs, slamming of the forefoot down into an unexpected sea. You imagine the movement, you name it, all ships will have done it thousands of time before the idea entered your head. What is happening is that the sea is constantly moving up and down, and sideways, and whatever way it wills, without cease.
When the great ships move, the sea moves equally and oppositely.
continuing “As I was saying”.
When the sea moves in such unpredictable manners, how on earth does one measure the change in the sea level height? To within centimetres?
No, no, Peter! To millimeters!
It’s always “worse than we thought”. Clearly, the problem is in the thinking. Evidently thinking is not a strong suit for climate scientologists.
+1
How come with CAGW its ALWAYS worse than we thought? And yet meanwhile we enjoyed a beautiful summer here in Texas, the best since…well the end of the other El Ninos.
One would think if EVERYTHING is worse than we thought, someone would have noticed without a (pseudo) scientific study!
This month, so far, not too shabby, either…
So our best and longest established measures are understating sea level rise but his new and short term measures are much better than the best. Say what? Rubbish!
Ah so a glacier melts in the Himalayas or the Alps and the closest coast line has a “melt fingerprint”.
FFS, maybe there is an LSD fingerprint on their brains, but pretending that there are measurable gravitational effects on regional sea level from glacier melt is laughable. Did they account for gravitational changes in groundwater, sedimentation, biomass, volcanism, and human infrastructure? I’d love to know what numbers they used to show the biomass-fingerprint for the Northern Hemisphere vs South, and what numbers did they use for Antarctic melt for that matter.
If the data don’t fit the theory, change how the data is collected. Science.
“If the data don’t fit the theory, change how the data is collected. Science.”
Talk to Hubble and Einstein.
https://www.cfa.harvard.edu/~dfabricant/huchra/hubble/
http://www.neatorama.com/2006/12/19/four-things-einstein-got-wrong/
When Einstein developed his theory of gravitation, usually called general relativity, he found a problem. The universe, which he thought was static, could not be static according to his equations. Instead of predicting that the universe was changing, he modified his equations to introduce a cosmological constant that would support his theory. When physicist Edwin Hubble discovered that the universe was not static but was expanding, Einstein called his cosmological constant “the greatest mistake of my life”.
And yet, I’ve never seen you admit any mistake, Mosh.
To quote you, “Raw data is crap data.”
How many thousands of times have you modified your data?”
People who live in government funding glass houses shouldn’t throw stones.
Mosh has a point.
The theory was put forward, and then we went looking for the data to support it.
The most astonishing thing is, that while the theory was looking a bit dodgy in the beginning, it has turned out that all of our old, previously collected data was wrong, and has had to be adjusted.
Everywhere we look, it is obvious that the data has NOT been keeping up with the theory, and armed with the knowledge of what the data should be, it is a relatively simple matter to find the faults.
Even as we predict the dire theorized outcomes, and these are contradicted by actual events, we find it a simple matter to remodel the situation, and soon enough, we can come up with a new set of dire outcomes to match the observed results.
It ain’t rocket science.
markx said:
“Mosh has a point.
The theory was put forward, and then we went looking for the data to support it.
The most astonishing thing is, that while the theory was looking a bit dodgy in the beginning, it has turned out that all of our old, previously collected data was wrong, and has had to be adjusted.”
If more people understood the logic behind that statement, we’d see a lot more genuinely skeptical thinking applied to both sides of the argument.
Mosh: Your link to changing values for the Hubble constant was fascinating, especially the error bars. We need to remember that statistics can only tell us about random error (in measurements), not systematic errors in converting those measurements into H0.
I hope to see a plot of ECS versus time that declines. A factor of 2 would be enough.
Dear Reg: Edwin Hubble was an astronomer, not a physicist (though astronomers understand and work with physics). He discovered a systematic galaxy redshift proportional to their distance…but he never interpreted it as a redshift due to Doppler shift (of recession velocity, implying universal expansion). The Doppler shift explanation was a supposition, which crystalized into “settled science.” Hubble argued against it.
For the rest of the story, read the work by Halton Arp.
Actually, Mosher, Einstein changed his theory because he didn’t like the conclusion. He DID NOT change any data.
And, unlike some, when data came in that showed his personal belief was wrong, Einstein promptly admitted it.
Face it, Mosh, not only are a lot of people smarter than you, they also tend to be honest.
Putting this into perspective, the PSMSL tide gauge network shows an average sea level rise (SLR) of 1.4 mm per year – roughly the thickness of a dime. Based upon the results of this study, you’re looking at a rate of 1.7 mm per year or 0.3 mm per year difference – the thickness of a business card.
Per PSMSL, most of the sea level rise is concentrated in the Baltic and Adriatic seas, South East Asia and the Atlantic coast of the United States, accounting for an average of 3.8 mm per year, representing 35% of global tide gauges. Sea levels were stable in 61% of gauges, and fell on average of 6 mm per year in the remaining 4% of gauges. All based upon gauges with long records.
This begs a statistical question… Given that some adjacent tide gauges showed opposite sign of SLR. And given sufficient samples (there were approx. 725 gauges in the network at its peak), wouldn’t the central theorem apply, making the need to adjust for some selected locations, as this study does, unnecessary?
“The data do not support our hypothesis. After a lot of head-scratching, we have developed a hypothesis about where to find data to support our other hypothesis. So our original hypothesis is supported by the data our hypothetical new method would have produced. QED.”
If they are so concerned about an error of only 3 cm. or so over a considerable period, could they explain how they are scientifically, accurately and adequately measuring the annual average sea/ocean surface levels, even for the last 30 years or so, let alone for, say 100-250 years. Everywhere and to varying extents and variously at different times, the sea surface swells with the crossing winds, its level adjacent to land varies with the changing tides, the sea bed level varies over time due to subsidence, ocean currents’ scouring and even geological/volcanic actions, and the sea water volumes alter with the extent of ice in the Arctic and Antarctic. From this they somehow calculate to a fine degree local annual average sea level changes with some supposed high level of accuracy and consistency sufficient to provide credible, meaningful and “substantiated” sea level changes. Then they somehow separate out the minute sea level changes supposedly caused by global warming and climate change.
Credible? Or am I somehow missing something, or misunderstanding something?
I gotta tell ya man that last 3cm is a bitch!
I know what i would say to any geologist who presented me with a model which showed all the high points of a variable far away from any actual data point……..
These alarmists have no shame.
Never bet the over-under in a rigged game.