Guest post by David Middleton
When the observations don’t match the models, adjust the observations…
Satellite snafu masked true sea-level rise for decades
Revised tallies confirm that the rate of sea-level rise is accelerating as the Earth warms and ice sheets thaw.
Jeff Tollefson
17 July 2017
The numbers didn’t add up. Even as Earth grew warmer and glaciers and ice sheets thawed, decades of satellite data seemed to show that the rate of sea-level rise was holding steady — or even declining.
Now, after puzzling over this discrepancy for years, scientists have identified its source: a problem with the calibration of a sensor on the first of several satellites launched to measure the height of the sea surface using radar. Adjusting the data to remove that error suggests that sea levels are indeed rising at faster rates each year.
“The rate of sea-level rise is increasing, and that increase is basically what we expected,” says Steven Nerem, a remote-sensing expert at the University of Colorado Boulder who is leading the reanalysis. He presented the as-yet-unpublished analysis on 13 July in New York City at a conference sponsored by the World Climate Research Programme and the International Oceanographic Commission, among others.
Nerem’s team calculated that the rate of sea-level rise increased from around 1.8 millimetres per year in 1993 to roughly 3.9 millimetres per year today as a result of global warming. In addition to the satellite calibration error, his analysis also takes into account other factors that have influenced sea-level rise in the last several decades, such as the eruption of Mount Pinatubo in the Philippines in 1991 and the recent El Niño weather pattern.
The view from above
The results align with three recent studies that have raised questions about the earliest observations of sea-surface height, or altimetry, captured by the TOPEX/Poseidon spacecraft, a joint US–French mission that began collecting data in late 1992. Those measurements continued with the launch of three subsequent satellites.
“Whatever the methodology, we all come up with the same conclusions,” says Anny Cazenave, a geophysicist at the Laboratory for Studies in Space Geophysics and Oceanography (LEGOS) in Toulouse, France.
[…]
“As records get longer, questions come up,” says Gavin Schmidt, a climate scientist who heads NASA’s Goddard Institute for Space Studies in New York City. But the recent spate of studies suggests that scientists have homed in on an answer, he says. “It’s all coming together.”
If sea-level rise continues to accelerate at the current rate, Nerem says, the world’s oceans could rise by about 75 centimetres over the next century. That is in line with projections made by the Intergovernmental Panel on Climate Change in 2013.
“All of this gives us much more confidence that we understand what is happening,” Church says, and the message to policymakers is clear enough. Humanity needs to reduce its output of greenhouse-gas emissions, he says — and quickly. ”The decisions we make now will have impacts for hundreds, and perhaps thousands, of years.”
- Nature
- doi:10.1038/nature.2017.22312
So… They accomplished accelerated sea level rise by slowing down the past…
Of course, Bill Cosby invented the word “riiiiight” in a sketch about accelerated sea level rise…
Oddly enough, Dr. Nerem and company predicted that they would soon detect the irascible acceleration in sea level rise. So, I guess the soon-to-be-detected acceleration will be tacked on the the adjusted acceleration and Bill Cosby will probably not get credit for the inundation of our coastlines when they are submerged under 7.5 meters of adjusted sea levels.
Until then, sea level rise looks just as tame as it ever did…
Featured Image: Cartoons by Josh
Adjustments to satellite sea level data started between 2000 and 2003.
To my knowledge, they’e adjusted:
Argo temperature data from the ocean
Satellite (RSS)
Land temperature
They changed the way the measure the arctic sea ice area
And now the satellite sea level data.
It would be very informative if WUWT could summarize every single climate metric adjustment made in a short article.
The number of changes to the CAGW story is approaching the scale of an Encyclopedia.
Ha ha ha ha ha ha ha ha ha ha!
First chuckle of the day.
I can tell you exactly what sea level did in the year 2013, 2012 and 2011 according to the tide gauges.
It actually fell by -0.345 mm in 2013, rose by 4.25 mms in 2012 and rose by 2.79 mms in 2011.
This is from 150 tide gauges that are co-located with GPS stations (that have around long enough so that we have verifiable vertical land movement numbers).
From 1960 to 2013, the 150 tide gauges measured an average absolute sea level rise of 130.026 mms total or 1.944 mms/year. 53 years
From 1960 to 2012, the exact same 150 tide gauges measured absolute sea level rise of 130.371 mms total or 1.988 mms/year. 52 years.
So, 150 GPS-adjusted tide gauges says sea level fell by 0.345 mms in 2013. That is not acceleration people.
In 2013 sea level altimetry said sea level fell by -1.10 mms. GPS adjusted tide gauges -0.345 mms.
In 2012, sea level altimetry said sea level rose by +7.60 mms. GPS adjusted tide gauges +4.25 mms.
In 2011, sea level altimetry said sea level rose by +6.66 mms. GPS adjusted tide gauges +2.79 mms.
———————————
The sea level altimetry from 2010 to 2013 +13.5 mms. 150 GPS adjusted tide gauges +7.05 mms.
Take their numbers and divide by two.
The data can be obtained here:
http://www.sonel.org/-Sea-level-trends-.html?lang=en
and,
https://www.aviso.altimetry.fr/en/data/products/ocean-indicators-products/mean-sea-level.html
I realized I can use this methodology for the whole satellite adjustocene period.
1992-2013 Adjusted satellite sea level rise – 67.2 mms – 3.20 mms/year
1992-2013 GPS adjusted tide gauges – 44.7 mms – 2.12 mms/year
Fakenews adjustments – the new GOLD standard everyone should be quoting from now on – 2.12 mms/year from the tide gauges.
————————–
1960-1992 GPS adjusted tide gauges – 58.3 mms – 1.82 mms/year
So there might be some slight acceleration but 2.12 mms.year is a long way from 2 feet of sea level rise as in 280 years away.
You’re right. Over-precision.
I’m just stating the mathemtical average of 150 tide gauges which all have numbers quoted to 4 decimal places in mms. The satellite number are always quoted to 2 decimal points on a millimeter baiss which is rather ridiculous considering the satellites have no hope of getting within 50 mms if you ever saw the YouTube video on sea level. The error margin is probably close to 1 metre although it is oftem quoted in papers as within 1 mm.
Just imagine trying to visualize a change in the height of the never still sea by one one-hundredth of a millimeter!
This would be hard to do in lab with a beaker of water.
Considering we have actual physical landmarks in and on the ocean which were photographed in the neighborhood of a hundred years ago, compared to these same landmarks photographed today, show very little if any discernable variation…this has got to be the backstop of any reality check on sea level.
No one will have their home flooded based on what is happening in the mid ocean, let alone the sea floor.
For problems to occur, the ocean will need to be on land in places where it never was in the past.
Let someone show where this is demonstrably occurring or verifiably has occurred.
I’m sure I saw a reply from someone that a convict made tide mark in Tasmania still matches current levels and one in Sydney same same .
As for age I thought it was 150 or so years old .
Maybe this will help. A mean tidal mark carved into the rock face in the early to mid 1800’s in Tasmania. http://morningmail.org/isle-of-the-dead/ It’s a bit too static for most climate scientist to comment on these days though.
http://morningmail.org/wp-content/uploads/2015/05/isle-of-the-dead.jpg
The general assumption seems to be that only thermal effects and glacier melt influence eustatic sea level but there other factors at play. The sediment dumped into the oceans by the world’s rivers has a measurable effect, although less than 0.5mm. But totally unknown is the net effect of the ocean floor interchange between the positive effects of water from sea floor vents and the movement of water in and out of subduction zones.
MR. You are forgetting the contribution of groundwater. Any ideas?
MR, I looked into groundwater. In the scale of things, it is de minimus. Most ground water is not declining measured by water well depths. That which is (Ogallalla, Punjab) is de minimus. Simple arithmetic applied to ground water facts.
On Galveston Island, more than 1/2 of the tide gauge sea level rise is due to groundwater withdrawal.
The Pier 21 and Pleasure Pier tide gauges exhibit 2′ per century of SLR. Subsidence due to groundwater withdrawal from 1906-2000 was about 1.5′.
The groundwater of the Perth floodplain has been harvested so much that the Fremantle sea levels have shown to be above the levels of other West Australian gauges: https://pindanpost.com/2012/12/15/perth-is-still-sinking/
Other gauges on the West Australian coast show levels falling since 2011 https://pindanpost.com/2017/04/13/falling-sea-levels/
Well, whatever is causing the slow and steady rise of the ocean sure is steady, isn’t it?
For over a hundred years and no matter if we are cooling or warming, mountain glaciers advancing or receding, Greenland, Antarctica…Aral Sea…all a wash, apparently.
And if you go back more than a century you see shoreline changes in both directions.
Sedimentary geology wouldn’t exist without a buttload of shoreline changes in both directions… 😎
Subsidence and plate tectonics, don’t count in the equation?
They are major factors in the equation.
Why no attempt to corroborate their claims with other sea level measurement data,from tidal gauges, etc? As far as I know, satellite measurements are not very accurate compared to the other methods. So I don’t know what they are doing and why they are doing it the way they are.
And, once again, they act as if they have an inkling of what will occur for the distant future. We can be certain that technology guarantees that “things won’t be the same,” and anyone with eyes in his head can see the coming transformation of personal conveyance to electric cars and the obvious advantages of molten salt nuclear reactors for providing power. To the exxtent that carbon effects anything, it won’t be doing so for the long term, regardless of whether these alarmists take any actions or not.
I was just wondering, can children cut themselves on Occam’s razor? If so, then maybe this is what happened to many current climate scientists, as they elevated the idea of choosing the least complicated explanation from a collection of possible explanations to absurd heights. The least complicated explanation, then, is the one you help engineer via adjusting things to fit expectations.
Might I suggest that a course in razor safety is in order, as part of all advanced degree requirements.
How about 0.75 M of supposed “rise” instead of 7.5 M ?
“At this point, what difference does it make?” We’re living in the Adjustocene!
Here’s the relevant paragraph:
“The team eventually identified a minor calibration that had been built into TOPEX/Poseidon’s altimeter to correct any flaws in its data that might be caused by problems with the instrument, such as ageing electronic components. Nerem and his colleagues were not sure that the calibration was necessary — and when they removed it, measurements of sea-level rise in the satellite’s early years aligned more closely with the tide-gauge data. The adjusted satellite data showed an increasing rate of sea-level rise over time.”
This is a textbook example of the “begging the question” fallacy. They note a discrepancy between the tide gauge and satellite date, presume that the tide gauge data is more accurate (the first unproven assumption) then presume that the calibration built into the satellite sensor, to correct for defects that occur over time, aren’t necessary (the second unproven assumption), eliminate that calibration and and conclude that the old data was bad because this changes the trend to get closer to the tide gauge data.
Reanalysis = Confirmation Bias = No Clue = Political Corruption = Abandoning Science and the Scientific Method,
“The rate of sea-level rise is increasing, and that increase is basically what we expected,” says Steven Nerem, a remote-sensing expert at the University of Colorado Boulder who is leading the reanalysis.
Since the temperature increase is not at the level they expected, if the sea-level rise IS what they expected, wouldn’t that imply the model of the sea-level rise is incorrect?
They are all over the map regarding ice as well.
Is Antarctica gaining or losing ice?
What about Greenland?
Mountain glaciers?
Is the ocean warming?
Are we pumping ever more water out of the ground over time?
Are some large inland seas and lakes being drained or not?
We know that the trends in all of these that we have numbers on has varied quite a bit over the past hundred to hundred and fifty years…and yet tide gages show a very steady trend, with any short term variations easily attributable to ocean currents and wind fields and such.
So how is it that sea level rise has been very steady while the factors noted above which are thought to cause the variation in sea level have been either all over the map, showing reversing trends, showing first no trend and then recently a sharp trend on one direction…
In fact before the Adjustocene Epoch began, published graphs of sea level over time did not show a steady trend of rising sea level at a steady rate.
As with most of the fields of inquiry that have been smudged and smeared by the dirty hands of the climate mafia, exactly what the heck is happening with sea level is less certain now than ever.
These people do not illuminate, they obfuscate.
They make it impossible to have much of any idea what is actually happening.
it would appear the manufacturers of all types of sensors used by nasa and various other governmental organisations employ complete and utter idiots. it seems all the sensors involved in measuring climate phenomena like water temps, wind speeds, storm occurrence,air temps etc do not work . when will the government be suing the manufacturers of all this equipment for selling them sensors under false pretences ?
any sensor designers/manufacturers care to shed some light on this apparent lack of ability ?
Remember that these sensors generally do not measure ocean height, water temp, etc directly. They measure such things as average radar returns over a given area with a given transmission frequency and pulse type and IR radiation in specific bands. These can be measured quite precisely. Interpreting them to derive the physical phenomena being studied is quite a different matter and is the scientist’s problem, not the instrument maker’s. If a pixel in an IR sensor gives a value of X, how much of that is due to temperature and how much to reflected light from the Sun? What exactly should be assumed for the emissivity of the surface and how does it deviate from the theoretical blackbody curve?
In the case of measuring ocean height, it is silly to even think of trying to directly measure an average “plane” to submillimeter accuracy when the measurement is affected not only by every wave, storm, and passing boat but the solar wind, Earth’s very non-smooth gravitational field, and the occasional micrometeorite. Needless to say, there’s a lot of averaging being done.
It’s all very difficult. Satellite and launch vehicle technology is difficult, but most of the overruns and delays in a space program are due to instruments. Often these are one-off builds at the edge of technology that no one has ever done before. If it has been done before, the next one is expected to be more precise with greater capabilities.
Remember, in this case, you are trying to measure something on a certain spot on the ground or air or water at a certain time and angle. Since satellites drift, you may not be exactly sure of the point where you are observing from, either. The measurements are often done indirectly, measuring some secondary item which corresponds to what you are wanting to measure. It is expected that there will be difficulties, overruns, and even sometimes failures. It really is amazing that we can do this stuff at all.
GIGO. Garbage in Gospel out.
Again I note the scientific invalidity of sea level change data in the absence of a great deal of required measurement of the deep oceans that are the lower 50% of the global ocean system. E.g. we have inadequate measurement of whether sub ocean crust is moving, of whether the deep ocean temperature is effectively constant (it cannot be totally constant with volcanism), of deep sea density constancy and so on. Would you drink a cup of microwaved soup without first testing for hot pockets near the base of the cup? Although stirring is a remedy, it is not a proper remedy for use in science, nor is spin. Geoff
By admitting that one little adjustment to one sensor on one satellite can change the entire record of what they are measuring, as this satellite-measured sea level rise paper does, they are saying right out in the open how subjective and speculative is the entire process they are engaged in.
I mean seriously…the entire crew of them where all wrong about everything for many years and no one had any idea…until someone noticed something needed to be adjusted just so?
And once that was done…viola!
GBAFB!
It does not get any more ludicrous.
Skeptic are hardly required…they completely undermine their own credibility by admitting that everyone in the whole field was clueless for years and years.
If the satellite in space gathering data which is then processed and a result synthesized, does not verify with the actual steel pole anchored into the ground in the actual ocean measuring the actual height, well…
Of course, there is no way, absent some independent verification, to know if they were wrong before, or if they are wrong now, or both.
You do not need to know anything about climate science or sea level or satellites to see what is going on…all you need to do is apply what is known about human nature, from every other aspect of our life experience, to this particular situation.
How often are the people who are constantly changing their story the ones who know what they are talking about. How often are they the ones who are trustworthy? How often are such people being honest and frank?
GBAFB means exactly what?
Check the urban dictionary.
It means :Give Me A ******* Break.
It’s been looked at. From memory, I think that the data — especially on ground water extraction and replenishment — is dubious. But I’m pretty “they” concluded that in the modern era increases in sea level from ground water extraction probably have been just about offset by increased surface storage of water in reservoirs.
“…increases in sea level from ground water extraction probably have been just about offset by increased surface storage of water in reservoirs…” Wha? Ground water extraction reduces land height and so does adding a reservoir.
“Ground water extraction reduces land height…” The question was how much does extracting ground water raise sea levels (when the used water eventually runs off to the ocean), an effect that is at least partially offset by reservoirs temporarily removing water from the cycle.
David: There is nothing wrong with scientists identifying real problems with their data and re-analyzing that data to adjust for an unambiguous problem. (Take TOB bias in temperature records for a relatively simple example.) The problem with satellite altimetry is that it requires dozens of adjustments made by humans who believe they know what should be happening to SLR and suffer from confirmation bias when making corrections. Every paper ends concludes with a statement saying that the “SLR budget is closed”. Here is the new and old data:
rate: +3.2 ± 0.4 mm/yr (AR5) has now become 2.6 or 2.9 ± 0.4 mm/yr
acceleration: −0.057 ± 0.058 mm/yr2 (unmentioned by AR5) has become +0.041 ± 0.058 mm/yr2
The smaller rate is based on corrections from GPS, the larger of a model for GIA.
Acceleration is still not statistically significant. But what does statistical significance mean, when such large systematic errors continue to be discovered after nearly a quarter-century of development? There have been at least two other corrections of this size.
We should be pointing out that the size of the SYSTEMATIC ERROR being corrected tell us the conclusion is fairly unreliable! This is a massively complicated program requiring dozens of adjustments made by humans with confirmation bias.
In the case of tropospheric temperature, RSS and UAH have independently developed competing methods for analyzing MSU data. However, the five groups reporting SLR rely on a common set of calculations about the orbit of satellites. And those calculations involve some fairly large correction factors, including one for humidity below the satellite from 0 to 40 cm. It doesn’t take much of a bias in this correction to change SLR by 1 mm/yr.
That GIA adjustment is 0.3 mm/yr, about a 10% increase in the actual rate. Colorado’s explanation: “The correction for glacial isostatic adjustment (GIA) accounts for the fact that the ocean basins are getting slightly larger since the end of the last glacial cycle.”
So what they’re reporting as sea level rise isn’t the level of the sea anymore.
Just noting that the average vertical uplift of the GPS stations is 0.41 mms/year. This is the simple average of all 500. So, the GIA adjustment is probably about right.
It doesn’t mean that the sea level is rising by this rate however, but that the land is rising by 0.3 or 0.4 mms per year. In effect, it is a “global warming motivated” adjustment only. The oceans are not in fact rising by the 0.3 mms/year but maybe the ocean volume is.
http://www.sonel.org/-Vertical-land-movement-estimate-.html?lang=en
Bill: If I understand correctly, GIA is supposed to correct for the subsidence of the ocean floor that accompanies glacial isostatic rebound under land. Subsidence of the ocean floor can’t be measured by GPS on land. Subsidence would cause sea level to fall if thermal expansion or net melting weren’t occurring. However, the papers at the CU SLR website suggest that many factors (including the changing moment of rotational inertia) other than simple subsidence are included in GIA.
I think both GPS and a model for GIA everywhere on the planet can be used to correct for vertical land motion at sites used to calibrate satellite altitude. IMO, there is no reason to believe a GIA MODEL when you have GPS OBSERVATIONS, but the GIA models is only a 10% reduction in previously reported SLR over 2.5 decades, while GPS says the correction is twice as big.
I agree 100%. The adjustments to all of the data, surface and satellite, are almost certainly valid.
The problem is that the “doomsday” predictions wouldn’t exist without the adjustments and fraudulent model scenarios like RCP 8.5.
++++
David: Climate scientists cite the ability of AOGCMs to reproduce the historic record of warming as evidence that these models can be trusted to forecast future warming. I’m not aware that the ability of models to hindcast current or past SLR has ever been cited as evidence that models can project future SLR rise from melting ice caps under any scenario (RCP 8.5, 6.2 or 4.5).
If so, it doesn’t make any difference if current SLR is 3.2, 2.9, or 2.6 mm/yr (+/- 0.4) or some other smaller value compiled from tide gauges corrected for vertical land motion. GPS corrected tide gauges should have much less potential for systematic error, but are less precise because they take measurements at fewer locations than satellite altimetry. Local weather (winds) affects local sea level, making tide gauge data far noisier than global data.
The problem with satellite altimetry is that a new major systematic error has been uncovered every few years. The corrected rate of SLR for any period can easily fall outside the 95% ci confidence interval previously reported for that period. Five years from now, the current rate of SLR for the period 1993-2016 could be 2.0 or 4.0 mm/yr.
An analogy: When measuring temperature over land, put your thermometer in the sun on the ground. To get the true temperature, you need to correct for the constantly varying intensity of solar radiation, the thermal emissivity of the thermometer, the rate at which horizontal wind from varying directions carries heat away from thermometer, and the rate at which vertical convection cools the hot surface. That is what they do with satellite altimetry; make large corrections for humidity (40 cm worth when converted to distance), and for wave height based on wind speed from re-analysis data.
The sea level at Fremantle in Western Australia has risen about 20cm over the last 100 years but, due probably to ground water extraction, the land is currently subsiding at 2 – 4mm/year.
[see discussion by Jo Nova – http://joannenova.com.au/2017/05/sea-level-rise-hysteria-can-be-cured-by-looking-at-tide-gauge-data/%5D.
At Port Hedland in Western Australia the daily tidal range is around 6 to 7 metres but tide measurements suggest no increase in sea level whatsoever since the late 1960s
http://www.bom.gov.au/ntc/IDO70000/IDO70000_62590_SLI.pdf
Perhaps the satellite sensor pointing at Port Hedland isn’t working
So the satellites used to agree with the only physical data source, tidal gauges. Now the climate charlatans are going to work to either “back adjust” the tidal gauge record or claim the gauges don’t matter.
We live in a shameful increasingly unhinged age.
“Whatever the methodology, we all come up with the same conclusions.”
And what conclusions are those? They always find what they are looking to find: “The rate of sea-level rise is increasing, and that increase is basically what we expected.”
Surprise surprise.
In this short video on ‘Sea Level’ the author claims they can only measure to the nearest Metre not Millimetre. Listen at the end of the Video.
DI,
Once again, we are confronted with the unanswered question of the justifiable, stated-precision of a variable whose deviation from a spheroid appears to be about two orders of magnitude (measured in meters) and even with a significant variation from a geoid, with a superposition of ‘rogue’ waves that can be up to 30 meters, and tides that are routinely about one or two metes in amplitude, all modulated by smaller waves that are out of phase. It seems that the unstated assumption is that one can assign any desired precision as long as there are a lot of measurements. And there isn’t even any mention of the Nyquist sampling rate criteria for the periodic waves: https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem
OK now there is justification to say….
Sea levels are rising at an increasing rate and all coastal cities will be under water before we know it…
Doesnt matter if they can justify an increase of an extra 0.000001 MM a year, the narrative is alive and can be exploited by the press and turned into we are all going to drown/die.
And of course they are right, we are all going to die sometime in the future.
Gavin and his cabal needs to be fired… urgently. Fake scientist make fake news. GK
Sea level acceleration? Doesn’t look like it
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The Adjustocene can only last so long. Already, the adjustments are as big as the signal in many data series
Link to image
http://postimg.org/image/avf10ulfn/
What, if any, was the final word on this study? I haven’t read all the comments here; apologies if this has already been addressed…
Earth’s surface water change over the past 30 years: ‘Nature Climate Change’ 8/2016
“Earth’s surface gained 115,000 km2 of water and 173,000 km2 of land over the past 30 years, including 20,135 km2 of water and 33,700 km2 of land in coastal areas…””We expected that the coast would start to retreat due to sea level rise, but the most surprising thing is that the coasts are growing all over the world,” said Dr Baart.””
http://www.nature.com/nclimate/journal/v6/n9/full/nclimate3111.html
http://www.bbc.com/news/science-environment-37187100
If correct; does this not ‘debunk’ the meme?
Cheers!