Guest essay by Eric Worrall
The United Nations has just warned the world that last year sea level rise hit an unprecedented 3.7mm.
Climate change is making the seas rise faster than ever, UN warns
28 March 2019
By Adam Vaughan
Sea levels across the world are rising faster than ever, the United Nations has warned, meaning we urgently need to increase action on climate change.
In a report released on Thursday, the World Meteorological Organization (WMO), a UN agency, painted a dire picture of all the key indicators of global warming.
The last four years were the warmest on record, concentrations of carbon dioxide in the atmosphere are at record levels and rising, and a global average sea level rise of 3.7 millimetres in 2018 outstripped the average annual increase over the past three decades.
The findings in the group’s annual State of the Climate report will bolster efforts by António Guterres, the UN secretary-general, to make governments commit to more ambitious carbon cuts at a landmark summit in September.
“There is no longer any time for delay,” wrote Guterres in a foreword to the report.
Last year was the fourth warmest on record, bringing the global temperature 1°C warmer on average than before the industrial revolution.
Read more: https://www.newscientist.com/article/2198091-climate-change-is-making-the-seas-rise-faster-than-ever-un-warns/
…
The WMO Press Release is available here, the actual report is available here.
Of course the report predicts more rapid sea level rise in the future. From page 16 of the report:
Over the period January 1993 to December 2018, the average rate of rise was 3.15 ± 0.3 mm yr-1, while the estimated acceleration was 0.1 mm yr-2.
Even if the UN estimate is correct, starting from 3.15mm per year this would result in a sea level rise of around:
d = vt + 0.5at2
d = 3.15 x 80 + 0.5 x 0.1 x 802
d = 572mm or just under 2ft of sea level rise by the end of the century.
I hope you all have your coastal evacuation plans ready. If this unprecedented rate of sea level rise per year continues, our children’s children might have to deal with 2ft of additional sea level by the end of this century. How will our grandchildren or great grandchildren cope with economic burden of constructing an extra foot or two of sea wall?
Not seeing it.
http://sealevel.colorado.edu/content/2018rel1-global-mean-sea-level-time-series-seasonal-signals-retained
Yep. In fact NOAA has been revising their long term trend (measured by satellite) downward over the last year or so from a high of 3.4 mm/yr to 3.3 then 3.2 and now 3.1 mm/yr. Apparently the U.N. isn’t au fait with the latest data which shows the opposite of what they claim. Sea level rise appears to be slowing, not accelerating.
https://sealevel.colorado.edu
https://climate.nasa.gov/vital-signs/sea-level/
Of course tide gauge data shows a lower rate of sea level rise and the slowing is likely due to the rebound from the large El Niño of 2016, but that’s far too technical for the simplified and perverse worldview of alarmists.
When you have a satellite radar with a wavelength of 2.5 cm, you cannot measure 0.1 mm accuracy. You just take two measurements, get the difference, divide by time, and run out as many irrelevant decimal places as you like. So for the Jason satellite series, sea level rise has never been observed.
Single pulse accuracy is 1.2 meters. 1000 pulse accuracy is 4.7 cm.
“1000 pulse accuracy is 4.7 cm.”
Hardly as both the satellite and the Earth have move between pulses.
You have 1000 pulse measurements across a line in the sea NOT at one spot. Can it indicate the sea level hight — sort of, probably but not particularly accurately as you have pointed out.
Now factor-in all those lunar and terrestrial gravitational effects on the sea levels, and things really start to get iffy.
Assuming an unbiased estimator, then with single pulse accuracy of 1.2 meters, 1000 pulses would have an accuracy of 1.2 mm. Estimators of a mean scale in accuracy as 1 over the number of samples.
Estimates of the standard deviation of a measurement, on the other hand, scale as 1 over the square root of the number of samples, which would be 3.7 cm if the 1.2 meters is the standard deviation of the standard deviation of the estimate.
Donald
I’d like to see how you calculated that number. I would like to know the sigma 1 uncertainty of the result for 5 and for 1000 measurements.
Does the calculation include a test to see if the 1000 measurements have a Normal distribution?
The Jason satellite work is an amazing inspiration for remote sensing students. I do feel they should communicate more “about the numbers”, not just the numbers.
Radar ranging takes millions of “measurements”. Your act of recording a dozen of them, and then making the decision to record a thousand of them instead, does not make it allowable for you to state that your measurement is more accurate. Its about a second year statistics comprehension quiz question.
Topex to Jason 1 drift is 100 mm. Jason 1 to Jason 2 drift is 75 mm. Each one is successively increasing the sea level reported by that amount.
Where are the university professors that teach physics and chemistry when it comes to criticizing measurement calculations. They would not let their students get away with ignoring significant digits and error budgets. Why do we never hear any criticisms from them about government agencies and U.N. agencies who massacre the very techniques and scientific application of measurement they teach? They should be ashamed!
If you take a single measurement, then your accuracy is limited. If you take multiple measurements, your measurements will display a distribution, that becomes more and more accurately centered around the true mean. This is true even if you round off your measurements.
The problem with the satellite measurements is that they are returning an unknown systematic error, which may be from adjustments made for estimated water vapor.
Steve O
The fundamental problem is that with SL and temperatures, you are not measuring the same thing multiple times. In the case of SL, one is measuring a range of heights that are perturbed over time by the tides, on top of which is superimposed ‘noise’ resulting from winds and low-pressure systems transiting the radar footprint. Where is the report of the standard deviation on that annual distribution? Precision and accuracy are related, but they are really two different problems. 1,000-pulse PRECISION may be 4.2 cm, but that doesn’t address the issue of systemic bias resulting from errors in the known altitude of the satellite, nor does it address the influences of tides, winds, and atmospheric pressure.
Multiple measurements of a chaotic surface actually increase the width of the distribution, even though they may seem to close in on an average. It’s not really possible to reduce the uncertainty through multiple measurements.
A trivial example: There’s no distribution around a single measurement but there is with 2 and more with 3.
A visual example:
Terrestrial telescopes observe stars with long exposure times to increase the number of photons observed. But they have to contend with the chaotic atmospheric fluctuations. The longer the exposure the blurrier the image becomes. This can only be eliminated by putting telescopes on high mountains or in space, not by increasing observational samples.
Wrong, you can only reduce random error through multiple measurements. You cannot reduce systematic or instrumental error. And in the end you must take square root of squares of all your error types, so the total error cannot be smaller than the instrument resolution.
I suspect satellite radar is using pulse compression, which can achieve much higher resolutions.
It is just fascinating how “sea level” is presumed to be a thing that can be measured at all. It is like measuring the level of a boiling pot of water. To “measure” it requires dampening or you cannot get any reading that is meaningful.
Also 0.3mm/y of that “rise” is a fictitious GAIA adjustment which assumes that the ocean basins are getting deeper. Even if true, that has ZERO effect on actual sea levels at any coast in the world.
The 3.7mm figure is given as 2017-2017 : a one year rise, ie. it is noise not a long term, underlying rise which can be related to “climate change”.
UN are getting more and more desperate that their power grab is failing. They disingenuously present a one year wiggle in statement about “climate”.
So when you have a noisy signal and you take the average over 30y , probably something like 50% of the individual year-to-year changes with “outstrip” the long term average. The other 50% will “understrip” the average.
Next time the wiggle goes downwards will their “State of the Climate” report give us the great news that that year’s sea level rise understripped the average annual increase over the past three decades?
Call me cynical but some how I doubt it.
Greg, the desperation comes from arising expectation that doing nothing about CO2 will show there is nothing catastrophic in “climate change”.
If they can get even a faulty agreement like half the Paris Accord in place, then they can take credit for a cooling period that appears about to take place anyway
I want to add, that it’s nice to know you guys and gals didn’t waste your money on a college degree! I have 3 girls and all three have art degrees. I’ve spent over $500K on them. It cost me a lot of money, so we’ll see, just how well they do.
I have enough left over to hopefully keep my 1994 Lexus running! Lol!
Jim, none of the three worked to help pay their way?
https://climate.nasa.gov/vital-signs/sea-level/
ground data says 1.6 mm year
Latitude
“ground data says 1.6 mm year”
Maybe you mean, like so many others, the rate for 1880-present?
The tide gauge rate you can obtain from the PSML data for 1993-2018 is about 3.2 mm/yr.
Again, a 25-year period (1993-2018) does not capture longer cyclical period changes. What are the past SLR cyclical changes? Multi-decadal periods up or down?
My pontoon is ready and waiting. Two by two we will march on board. Ships A-HOY!
Sea level has been rising for 200,000 years and will continue. I don’t exactly know how much rise since then, but 140 meters maybe? (I’m the least expert in the world.) probably why ancient civilizations are discovered under water. It’s a decent guess we’ll get about 5” of rise this century. As long as Greenland stays inside the Arctic Circle where it’s pretty darn cold, I expect. I’ve never been to Greenland, but seen pictures of it – it looks cold. I do know, it has 2,000’ of ice at its center. Again…seems like a lot of ice. According to Mario at mariobuildreps.com and his exceptional team of mathematicians, it will take about 4,000 years for Greenland to be devoid of ice (a great website, I might add). Not my problem…I just want to wake up tomorrow and pay my taxes! Lol
Nils-Axel Mörner says that the raw signal from Jason satellites is zero, and that the 3mm rise consists entirely of adjustments. In any case, Jason accuracy is 4cm, so the correct answer is always 0±4cm. Everyone who has studied physics knows – you are never allowed to ditch instrumental inaccuracy. It can’t be reduced regardless how many times you do the measurements – only the random error can be reduced in this way.
Erast Van Doren
That should be 4cm precision, not accuracy. The accuracy really isn’t known. Comparison to tidal gauges suggest the accuracy is very low.
Please see the following:
https://wattsupwiththat.com/2017/04/12/are-claimed-global-record-temperatures-valid/
https://wattsupwiththat.com/2017/04/23/the-meaning-and-utility-of-averages-as-it-applies-to-climate/
Speaking of accuracy, is there any relevant information on the positional accuracy of the Jason satellites themselves? The assumption is that they are in precise fixed orbits controlled or monitored by DORIS, but if measurements down to fractions of a millimeter are being claimed we surely have to know the orbital accuracy as well (presumably also to fractions of a millimeter) and whether further compensatory corrections have been made. Not my subject, but interested to know if there are any astrodynamicists out there.
If you are born today you will be 80 before you need to move you beach house. But you don’t actually need to be a “Climate Scientist” whatever that is suppose to mean, to correlate the recent news of Greenland’s reversal and Ice cap growth in conjunction with reversing sea level rise base on recent NASA data. Yet so few people use common sense.
After retiring early I looked into getting a degree in Climate Science but could’t find a nearby college that offered that education. Strange when considering all the bluster about who is qualified to speak out on Climate Science. Where do all those voters come from who make up this 97%. I simply wanted a vote but couldn’t figure out how to register. Seems it is a secret society voting thing.
These people are so transparently dishonest that it is an insult to everybodys’ intelligence. Just think about how “dumbed down” a person has to be to suffer from climate change anxiety as reported in an alternate post.
One problem is that few of the millions or even billions of people who might be exposed to the statement “The sea rose 3.7 mm last year!” can even picture 3.7mm, or comprehend how minuscule such a rise would be, even if were true. But they sense they should be alarmed.
Most domestic panes of window glass are 4mm thick.
Sasha
António Guterrez was sick the day they did mats at his school. He thinks it’s 3.7 many metres.
LOL
Are the foreign panes thicker?
John Bell
I strongly suspect that the UN pains in the @ss are thick.
Less than half the width of 8 mm film. Less than 1/4 the width of 16 mm film. A smidge over the width of 35mm film.
Any questions?
OOOOOPssss! That should be “a smidge over 10% of the width of 35mm film”.
Sorry. Did not proofread first. My bad.
Jason 3 says garbage to that.
The article linked just gives the number it says nothing of the source … anyone know the source of this junk.
http://www.drroyspencer.com/2019/03/is-satellite-altimeter-based-sea-level-rise-acceleration-from-a-biased-water-vapor-correction/
Couldn’t predict too much else the UN will need to build boat docks or similar around the UN Building in NY.
If you wonder what I am talking about check out my blog.
https://thedemiseofchristchurch.wordpress.com/2016/05/06/un-headquarters-and-usd1-2-billion-upgrade-and-rising/
Cheers
Roger
I still think we ought to give property to Trump and let him build condos, and ship the UN to Central Africa, so the stripey pants set can see what real problems are like.
It is junk…the coastal gauges don’t reflect an increase…this is pure rubbish, per normal UN standard operating procedures. Even if it did tic up a 10th of a millimetre or two, who cares.
Did they average that 3.7 mm globally or how did they arrive at that number? SLR is local, and in some places is going down as land rises. Or did they just pick one place on the planet where it is rising at 3.7 mm because the land is subsiding? But they get their headline and that is how they win with the great unwashed masses and the people who feverishly want to believe in this alarmist climate religion of doom. There is a lot of money and power at stake over the citizenry in all this.
Fixed bridges on the IntraCoastal waterway have a clearance of 65’, (some are higher) and sailing boats designed for US East coast sailing generally have a mast height of around 64’6” max. Add a VHF antenna to the top and you tend to ping the bridge. The bridge height was fixed decades ago so if the sea level rise is as much as were being told then soon few boats will fit under the bridges, or maybe sea level doesn’t affect the ICW!
One man’s dystopian marine future …
https://www.rogerebert.com/reviews/waterworld-1995
Is another man’s adventure!
I look forward to my great grandchildren being born with webbed toes.
Hmmmm, look for Colorado University’s Sea Level Research Group to update their webpage
http://sealevel.colorado.edu/
that hasn’t been updated for well over a year.
They don’t dare because Jason 3 data is flat they will have to published a reduced rise .. from memory it will drop to like 2.9mm/year.
No a message they want to post.
It’s the University of Colorado.
“Last year was the fourth warmest on record, bringing the global temperature 1°C warmer on average than before the industrial revolution.”
Even if this claim was true and there had not been the widespread reduction of historical temperature records, no man or beast would have noticed a 1 degree C increase (or decrease) in temperature, even if it had occurred overnight. The people in the pre-Industrial era would have been greatly encouraged to hear that their great-great-great-great-grandchildren would be spared the grinding winters that they had themselves suffered.
Looking at António Guterrez, Secretary-General of the United Nations, I would have to say that I would not have bought a used car from him. With no scientific backing or quoted data, a claim of a rise of 3.7-mm. in the seas, is quite vacuuous. There has been no such increase in high or low tide records in Sydney Harbour last year. Where is their evidence?
The BBC were at it again last night in their Blue Planet series of CAGW alarmism. Accurate quote “The temperature of the world’s oceans has risen by one degree in the last 50 years.” (They usually use Centigrade in their pronouncements, but 1.8 degrees Fahrenheit would have been “better”. They never say Celsius of Kelvin because they know it would have no mental impact. )
An unforgivable and nonsensical generalisation, again. If I had the time I’d do the heat calculation, but I have better things to do and too few years left to pander to their corporate idiocy.
Is it just me, but does eyeballing the graphs indicate rising sea levels have been leveling over the past few years?
Satellites with an accuracy in the centimeters (at best) measuring SLR to the tenth of a millimeter? I’ve read the various apologia, but it is still all arm-waving.
To the best of my knowledge, tidal gauges (adjusted for local land rise and fall) show no such acceleration, much less the 3+ mm/yr rise derived from satellite measurements. Will the UN IPCC’s AR6 sort this out?
They have been levelling because Jason 3 has seen very little rise. Jason 3 processes waves height differently to the old Jason 1 & 2 and what seems to have been happening is wind strength around the world had increased and thus you got increased wave height. As Jason 3 doesn’t see the increased wave heights the sea level rise data has flattened.
Exactly. Ask an alarmists – can you measure thermal expansion of a table with a tape measure? Nope. The expansion is in the range of a 0.1mm, while tape accuracy is ca. 1mm. Doesn’t matter how many times or how many tables you measure – the answer will always be zero.
Australia has a long running coastal sea level monitoring program with 16 standardised sites dotted around the coast. If the WMO global data is correct then Australia is being inundated 27% faster than the rest of the globe with an average annual rate of 4.7mm/yr.
http://www.bom.gov.au/ntc/IDO60201/IDO60201.201902.pdf
This data is corrected for ground movement.
There is no acceleration. The rate was 4.75mm/yr a decade ago. So good news if you have an existing waterfront or bad news if you are on elevated ground and living in hope of rapid sea level rise to attain a waterfront.
As always all the acceleration is anywhere you don’t have a sensor or direct measurement 🙂
Given their impeccable reputation for honest nonpartisan data-keeping I’m sure the BOM stats are correct for the continent as a whole, however the Sydney tide gauge record from 1890 shows a linear trend of +0.74 mm/yr:
http://www.climate4you.com/images/Sydney-NEW.gif
On the same page @ climate4you Fremantle since 1900 on the other side of the continent shows a linear trend of +1.67 mm/yr.
There is a big gap between say +1 mm/yr (splitting the difference) and 4.75 mm/yr.
You don’t actually believe something coming out of BOM?
NOTICE the lack of mention of the +/- 0.4mm error! Also the sample period is three decades only???? What kind of scientists are comming up with this and WHY are scientists not offering themselves up for cross examination. As usual the “bad news” is given by a politician.
Jon Scott
“…lack of mention of the +/- 0.4mm error!”
It isn’t actually an error. It is a range of uncertainty of the nominal measurement. That is, it is a bound on the precision.
Clyde,
I’ve been researching university web pages on significant digits and uncertainty propagation, and one of them made your point. The author had a bit of a sense of humor, too. He said “error” was a “terrible” word, and that’s why it’s called The Heisenberg Uncertainty Principle, and not “The Heisenberg Error Principle.”
Thirty years on the high side of an approximately seventy year cycle? In a world recovering from the depths of the Little Ice Age?
Ignore the bigger picture, and focus on the fear factor.
BECAUSE as with all other land based sea level monitoring NO allowance is made for isostasy. This is nothing less than wilful. That is why the northern coast of Australia is “sinking” quicker than else where. Nothing to do with sea level it is land level change!
“The United Nations has just warned the world that last year sea level rise hit an unprecedented 3.7mm …”.
=========================================================
The linear trend 2005 – 2017 was +3.81 mm/yr so the supposed rate of sea level rise, according to satellite data, must be slowing:
http://www.climate4you.com/images/SeaLevelSatellites-NEW.gif
Chris Hanley
“The linear trend 2005 – 2017 was +3.81 mm/yr so the supposed rate of sea level rise, according to satellite data, must be slowing…”
Certainly it isn’t. Because if it was, then the linear estimate for 2005-2017 would have to be lower than that for 1993-2017. But… 3.81 seems to be a little bit higher than 3.16, isn’t it?
Please have a look at the picture you yourself referred too…
I was being a bit mischievous.
What a beautiful word…
3.7 mm! We’re doomed!
PAY NO ATTENTION to the ~3,000mm sea level rise from tropical storm surge making landfall, behind the curtain.
Gah! No! You mean we only have what, 80 ish years to built a 3 to 4 brick high sea wall to save us !? Lordy me I might need a bit of a lie down.
Most of your houses will have been replaced by then … in any city try a guess at how many +100 year old buildings exist.
For good old New York there is actual data to look at
https://www.citylab.com/life/2013/09/map-shows-ages-million-buildings-new-york-city/6932/
In good old London, England, most of the housing stock is considerably older than 100 years.
The Palace of Westminster (the seat of our government) dates back to the 11th Century.
Interestingly it’s built on the banks of the River Thames and is in such a state of disrepair that it will soon undergo major refurbishment costing some £5bn. Judging by past government projects that’s liable to be £10bn by the time they are finished (I kid you not).
Being that SLR is ‘accelerating’ that would seem an awful waste of money as at full tide the river is mere feet below the level of the Palace which suggests one of two things:
1. Wild assessment of SLR are just so much crap and the British government is well aware of it.
2. Despite supporting the grossly expensive Climate Change Act, our government officials don’t know what it means (entirely likely).
If it helps visualize it this is New York 108 years ago
Wonderful video. Anyone who likes it should check out Jack Finney’s 1970 best-seller, “Time and Again,” a time-travel trip back to 1882 NY City.
Here in Australia, we had a science commentator claim 90 metres-a metre a year!! The guy was out by a factor of over 100! 2 orders of magnitude. Going by a logorithmic progression, since it would not be a millimetre every 3 days at this rate starting now, the rate would be a millimetre a day by year 2100. This is clearly a fantasy.I am calling this one-it is clearly a load of bovine excrement. To claim that one high reading is proof positive is NOT science.
A good appreciation of what globally happens is given by NOAA’s tide gauge data trends:
https://tidesandcurrents.noaa.gov/sltrends/sltrends.html
Click on ‘Global’ to have them all visible. As we can see, the majority of the gauges show a trend below 3 mm/yr. Notable exceptions are US’ east coast and East Asia, especially Japan.
What would be of further interest of course is to collect all the data and to see which places clearly show an acceleration in consecutive trends.
when corrected for local land subsidence (high accuracy long-series GPS makes this possible to do very accurately) sea level is only rising at about 1-2mm around the globe (eg in antipodean locations as far afield as Dunedin in NZ and New Lynn in UK both are at ~1.1mm/year. The Satellite data is unsupportable. Given large known thermosteric sea water expansion contribution (~1mm/year) and also large ground water extraction component (up to 0.5mm/year) it means that ice caps are not in fact shrinking to any significant degree.
Most inconvenient
But but … the Carteret atoll needs to be evacuated! It’s was halfway done already in 2015, so surely that and next Tuvalu (“Tuvalu is the most vulnerable country to the effects of climate change” -the UN). /sarc
[I don’t want to sound harsh. Should Tuvalu start disappearing into waves (which it is not doing as of now), I’m all in for adapting to sea level rise. I even support modest economical support in building sea walls, moving people to better locations, and developing economy of Tuvalu so that it can solve the challenges. Carteret’s example shows though, that some places are pretty difficult to help. An unmitigated population bomb voids any attempts to improve living conditions in absence of education, contraceptives, heath care and working economy.
But don’t talk shit about Tuvalu disappearing into ocean when there is no real sign of that happening.
Sea-level at Funafuti, capitol of Tuvalu:
(1994-2018)
(1978-1999)
As a matter of fact the sea-level at Tuvalu seems to be exceptionally stable, except for brief periods of very low sea-level during strong Ninos.
My understanding was that Tuvalu and most Pacific atolls have actually gained land mass over the last couple of decades due to wave action etc. Sorry, can’t quote the reference but most likely an article on http://www.notalotofpeopleknowthat.wordpress.com They’re not disappearing, they’re actually getting bigger.
Hugs
It’s difficult not to agree, especially when one never visited the corner in question.
The gauge ‘1839’ at Funafuti shows 4 mm/yr for 1994-2018, and 3.5 when excluding “sea-level during strong Ninos”.
Thus the layman can only say: “It looks like everywhere else”… and “Time will tell”.
The 3.7 mmyr-1 value for 2018 was obtained by fitting a quadratic function to the sea-level data (only satellite era and only satellite data, and probably including a more or less fictitious “GIA correction”).
I. e. the acceleration was obtained by assuming that there is an acceleration, not by actual measurement. There is nothing in the report to show that this quadratic function was a better fit than e. g. a linear regression. And of course the data are entirely unsullied by actual measurements of relative sea-level changes.
tty
Sorry: you have it all wrong.
1. The first line you read when accessing
http://sealevel.colorado.edu/files/2018_rel1/sl_ns_global.txt
is: Date 2018_rel1 GMSL w/ seasonal signals and GIA removed (mm)
2. Here is a comparison of that data with
https://www.psmsl.org/data/obtaining/rlr.monthly.data/rlr_monthly.zip
for the sat period 1993-2017:
https://drive.google.com/file/d/165M66btxeC5apsmo-h3XNgCBB4S_rEGI/view
3. Successive OLS estimates till 2017 for the sat altimetry:
1993-2017: 3.16 ± .02
1998-2017: 3.34 ± .02
2003-2017: 3.46 ± .04
2008-2017: 4.26 ± .06
Acceleration: 0.07 mm / yr². Very low indeed; but what is, is.
3. “And of course the data are entirely unsullied by actual measurements of relative sea-level changes.”
Some valuable proof at hand, tty?
So the ‘acceleration’ is less than the total error band, since at least 2003. Wow! (In what is the highly suspect ability of satellites to measure such small differences at all.)
There is only one sea level that matters and that is what the tide gauges show relative to land. Anything else is irrelevant as far as ‘threats’ go.
https://drive.google.com/file/d/165M66btxeC5apsmo-h3XNgCBB4S_rEGI/view
Anomalies.
You seem to belong to those people still ignoring what anomalies exactly are.
Bindidon
Sorry: you have it all wrong.
Read the WMO report:
https://library.wmo.int/doc_num.php?explnum_id=5789
Especially p. 16.
It does not use any of the sources you name.
You can find the data actually used here:
http://www.esa-sealevel-cci.org/node/284
Read the text underneath the curve. it says “The curve has been corrected for the GIA effect”.
Any comments?
Oh yes! I sent a data request by email to
Sea Level CCI
So we will see how the sources differ.
“Last year was the fourth warmest on record, bringing the global temperature 1°C warmer on average than before the industrial revolution.”
But before the industrial revolution we were in a cold period. so what is the problem?
Odd. isn’t it. If we went back a true 1C (rather than the 1C supposedly in the ‘data’) we would struggle to feed the world’s population.
As it is despite all the supposedly worsening extreme weather nearly every harvest of every type gets bigger year on year (with the odd local hiccup obviously).
Netherlands is for a large part below sea level. We take extra special notice of it and have been doing so for centuries.
Our sea level, measured by tide gauges, was lower by a whopping 72 mm in 2018. Granted mostly due to wind conditions but no acceleration detected here.
recent report is very clear on that.
https://www.deltares.nl/app/uploads/2019/03/Zeespiegelmonitor-2018-final.pdf
I’ve wondered why the satellite used to measure SLR only has a resolution of 2.5cm and not .1mm and then I remembered the prediction made by James Hansen in 1988. If the SLR had been 20 feet as predicted, then the 2.5cm resolution would have been adequate. Just an example of why you have to take scientific predictions with a grain of salt. I mean, you wouldn’t want to build billion dollar desalinization plants in major Australian cities based on a prediction by Tim Flannery that the rains will never return. Or destroy a perfectly good power grid because you think burning coal is going to melt the planet.
Lysenkoism is practised by our governments using failed predictions of prostituted climate scientists. Hundreds of billions of dollars have been wasted on this nonsense that could have been used for better good.
This is where the falsehoods start.
As tenuous an idea as a average global temperature
The report is at:
https://gallery.mailchimp.com/daf3c1527c528609c379f3c08/files/82234023-0318-408a-9905-5f84bbb04eee/Climate_Statement_2018.pdf
Page 16 has sea level in 2018 3.7mm higher than 2017
Sorry but nobody measures a rise in sea level of 3.7mm.
“Sea levels across the world are rising faster than ever, the United Nations has warned, … global average sea level rise of 3.7 millimetres in 2018 outstripped the average annual increase over the past three decades.”
Hmmm. So “ever” means any time over the last three decades. I always wondered how long “ever” was.
This means any list of the best U.S. Presidents “ever” must choose from either George H.W. Bush, Bill Clinton, George W. Bush, Barack Obama, or Donald Trump.
I was recently in Auckland NZ. I was enjoying a moment on one of the quasi private beaches that dot the bay at the end of every cul de sac around the coast road.
I noticed the sea rise by about 50 mm without any obvious reason. Then into view came a huge cruise liner generating a little bow wave.
It got me thinking how do you actually measure sea rise or sea level?
The variables that impact the site of the gauge or the signal from satellite ranging are real and some obvious others not.
Do the measurements take account of wind direction heaping the sea surface up local to the point of measurement? Do the measurements take account of the seismic effect of a minor movement out at sea causing the local ocean to rise by a few mm? Do the measurements compute tide variation with planet alignments? Do the measurements allow for wave length and scale? Do the measurements account for plate tectonic movement up and down local to the point of measurement.
The passing of large sea going ships is an obvious influence how is this factored in?
How about salinity changes following heavy outflows from large river systems.
The variables are almost infinite. So how reliable are these reported levels? Is it even possible to capture all the potential influences on the measurement and make allowance in the averages for them?
Over a year, noise swamps out the signal for sure. Over decades the signal, if above the noise, can be ascertained. In any case, historically, SL change has been much greater in both directions just within the past few millennia. SL was over 100 meters lower just 10 or 12 thousand years ago. On average it had to rise in 10’s of mm/year to get to where it is today.
It is just the opposite of what they say. Since October 2015 sea level rise has been below average. And if I am right it will continue being below average for a decade or two.
Holá Javier! ¿Eres serio sobre eso?
https://drive.google.com/file/d/1BFCiHTjEkj8LfNTIJFOqKpCyfeDOEegB/view
What would you have told us in… 2002? The same song?
Anyway: which average did you mean? Gauges 1880-2013 or gauges 1993-2018 or altimetry 1993-2017?
The graph you post shows that SLR since 2015 is at least flat, which is what Javier said, it being below the average of 1993-2018.
Earthling2
Are you eye-balling?
Averages:
– Gauges 1993-2018: +6.90
– Altim 1993-2017: +6.64
2015 looks a bit flatty indeed, but is WAY above average. What about a look at other places in the plots?
I wonder how they expect sea level to stay fixed when it never has. So last year was 0.25 mm above average and margin of error? A normal world. If you want sea side, accept the risks that go with it.
Amazing sea level acceleration despite loss of Greenland ice decelerated since 202 and gained ice the last 2 years. http://landscapesandcycles.net/sea-level-rise-conundrums-greenland-s-cycles.html
Satellites suggested sea level acceleratedby 3.5 mm/yr from 1993 to 2003. Then same analyses of new data had sea level rise decelerate to about 2.5 mm/yr.
Then the a flurry of various adjustments. These guys are so dishonest
Jim Steele
Thanks for the link inside to the Belgian paper.
What now concerns your comment above: I don’t understand exactly what you mean.
Why should Greenland’s SMB upshift automatically mean an SLR deceleration?
Aren’t there not enough other sources?
Who’da thunk it.
https://www.cntraveler.com/story/on-the-baltic-coast-of-sweden-and-finland-sea-levels-are-falling
Anyone want to calculate the displacement? Coz I can’t be arsed.
If you are interested there is a map here:
https://www.smhi.se/kunskapsbanken/oceanografi/landhojning-och-havsvatttenstand-1.3437
It is the same around Hudson Bay:
All because land has not yet rebounded after the ice melted 10,000 years ago.
From the article: “The last four years were the warmest on record,”
Does it look to you like the last four years were the warmest on record?
The UAH satellite chart:
http://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_January_2019_v6.jpg
Tom Abbott
“Does it look to you like the last four years were the warmest on record?”
No. Certainly not about 5 km above surface, and more than certainly 5 km above the oceans.
But maybe 2 m above? (I mean measurement, and not Dr Ryan Maue’s reanalysis).
Is that 2m above asphalt, concrete, shingle, next to air conditioners, truck exhausts, and surrounded by increasing human development, with the “benefit” of subsequent adjustments? Or do you think it might be better to base your temperature data and conclusions on measurements taken a little further removed from human influence?
Fenlander
“Is that 2m above asphalt, concrete, shingle, next to air conditioners, truck exhausts, and surrounded by increasing human development, with the “benefit” of subsequent adjustments?”
Do you have the simplest idea of
– How many stations are really affected by this huge list of errors?
– How are actual temperature measurements made by stations processed?
My humble guess: no you don’t. Because if you did, you wouldn’t ask that way.
*
Recently, we were fortunate enough to look at one of the many stations you very probably would suspect of being a victim of their location:
Hmmmh. USCRN station ‘Stovepipe Wells’
USW00053139 36.6019 -117.1450 25.6 CA STOVEPIPE WELLS 1 SW CRN 74613
looks indeed suffering of the sum of all these drawbacks you mentioned above.
But as I looked at this poor station’s immediate neighbour, I found this:
USR0000CHNM 36.5625 -117.4736 2097.0 CA HUNTER MOUNTAIN CALIFORNIA
As you can see, the two stations differ in altitude by a lot. Two thousand meter! Should their temperature record not differ similarly?
But when you compare their temperature departures from a common mean, you see this:
https://drive.google.com/file/d/1PFes9vlKFlELCnflL-WINhr0mkPlK_nf/view
How is that possible?
It is simply due to the fact that these departures are computed station by station, instead of being computed out of an anonymous average of things having nothing in common.
Thus two stations – one near a supermarket near sea, one in a very rural environment in the mountain – will indeed show very different absolute temperatures. But their departures from a common mean can be very similar.
Has everyone forgotten how desert water bags work? Why do I get the impression of a well-known, common, inescapable effect of water is being ignored? Latent Heat of Evaporation which is clearly shown in a desert water bag.
Desert water bags were traditionally made from a porous material like canvas, flax or linen. The bags were tightly woven to keep water in, but porous enough to allow a small amount to seep through the bag. A motorist could hang the bag on the outside of his vehicle or sling it across the hood during a drive, and the forward motion would evaporate the water that had seeped through the bag, cooling the water inside. As the water seeps through the porous cloth, the bag is covered in a film of, this water will then evaporate. Hikers even carried them to have cool water on trips in the desert areas or in warm areas. The process of evaporating takes energy from the system (called latent heat). This cools down the bottle. In a very dry environment, the surface water will even evaporate in the sun in a calm area without a breeze and provide some cooling.
This cooling effect from the latent heat of evaporation also works in an oven. This is demonstrated when you cook a roast. When you put your roast in an oven the moisture in the roast migrates to the surface. At the surface this moisture evaporates and provides a cooling effect to the roast. Just like the Desert Water bag or you when you sweat. At the point of the change in state from a liquid to water vapor there is insufficient energy in the heat energy to effect this transformation and as a result some of the needed energy is taken from the roast cooling it a small amount. I am not claiming or even trying to suggest that you can cool a chunk of meat by putting it in an oven. However, this cooling action slows down the cooking so that a roast in an oven at 350 degrees F will take much longer, remaining below 165 degrees F until the roast is DRY and can no longer have the cooling effect of evaporation. And once DRY it will quickly burn. Place a digital thermometer in a roast the next time you make one and plot the temperature every ten minutes as it cooks. Notice the shape of the curve and how quickly it increases exponentially in temperature as the roasr begins to dry. The reason you keep water in the roasting pan.
It is my opinion that this same effect is where the heat “Hiding in the bottom of the ocean” has really gone. The energy from the Sun that is hitting the surface of the ocean is not just heating the ocean it is also cooling the ocean! When the Suns energy hits the surface of the water it is insufficient to completely cause the evaporation and some of that energy is taken from the water causing the water to be cooled. Further, some of that energy could be coming from the air around the water cooling the air and then the water. And of course, these actions will be enhanced by the wind on the surface of the water.
Also, what about LAND. When the sun his land it dries out the soil. As this happens it also cools the soil until there is no longer any water to percolate up to the surface and evaporate. Usually, when there is no longer enough water to percolate up to the surface the land turns into a desert.
How much of the Suns energy is actually cooling the Globe?
Since there is more ocean area on the lower hemisphere, how is the rotation of the Earth at it’s 23-degree slant around an elliptical orbit effecting the input/output of energy into the Climate Change debate. Seems to me that using a fixed albedo number is NOT a good approximation. Especially considering the MASSIVE wind and ocean currents pumping those temperatures and energy around the globe.
And then there is the Latent Heat of Fusion/melting demonstrated in making Ice Cream in a hand cranked Ice Cream Maker. Energy/heat can be used to make things colder. Appears to me that the “Climate Scientists” are ignoring very important aspects of water. Does their Ideology prevent them from using their brain?
I have a difficult time SEEING three millimeters. Let alone applying it to the global ocean surface.
I bet that António Guterrez, Secretary-General of the United Nations, puts on more that 3.7 mm of fat to the circumference of his belly every year flying around in first class and private jets consuming food and beverages like the glutton that he appears to be.
Water vapor is highly reflective at 6 cm wave length. It is less reflective at 2.2 cm wavelength, but still rather reflective. Therefore, during times of dynamic water vapor content above the surface of the sea they must be employing a dynamic correction factor. The exact measurement is a guesstimate.
They can’t go lower wavelength than about 2 cm to further reduce the reflectivity to water vapor induced error, because at such short wavelengths water vapor begins to absorb the energy rather than reflect it. They would get no reliable returns.
Distance measurement with radar is a function of time. This applies to both distance measurement and distance resolution, which are not the same things. A pulse width of micro second provides a resolution for distance of 150 meters. They need to get the resolution for range to within the typical differential between wave tops and wave troughs, or the wave tops of the sea surface and the troughs will register the same reading. This is why Jason is obviously using a phase coherent method of measurement.
The pulse width in this case is actually greater than 100 micro seconds. This allows for sufficient illumination energy with only a handful of watts available on a satellite, because illumination energy is the pulse width multiplied by the transmitted power. The elapsed time measurement is actually made by comparing the phase of the return echo to the phase recorded by a device that is called the summer. This allows measurements from within the pulse to be made.
The accuracy of the distance measure is determined by how fine of a phase differential can be measured. Additionally, the bandwidth of the equipment will determine how sharp the transmitted pulse’s shape can be and therefore how finely it can be analyzed. 100% accuracy is only possible with infinite bandwidth, but as bandwidth increases so does the signal to noise ratio degrade. A trade off will need to be determined and yet more corrections employed. Accuracy to the 1/10 of a mm? I don’t think so.
KT66
The accuracy of the SL measurements is also influenced by the assumed height of the satellite. It can vary with the density of the atmosphere where the satellite is orbiting, which varies with the sunspot cycle. It could also be affected by water piling up under the influence of winds and increasing the gravitational attraction. Long-term shifts in the position and strength of mascons can also effect the orbital behavior of a satellite. A gravity model is used to estimate what the instantaneous height of the satellite is. But, in the middle of an ocean, there is no way to independently confirm that estimate. Thus, while the precision may be reasonably well known, the actual accuracy of the derived SL is much less less known and actually indeterminable.
Clyde Spencer
“A gravity model is used to estimate what the instantaneous height of the satellite is.”
Sure sure? Satellite laser ranging accuracy is below 1 mm, as is inbetween Lunar.
The JASON satellites use a combination of GPS, laser ranging and radio beacons (DORIS) to determine position. The claimed accuracy is about 2.5 cm, i e about 250 times the claimed precision of sea-level determination.
tty
The operative word here is “claimed.” I think that most of us here have come to be skeptical about any and all claims when it furthers the meme of CAGW.
Bindidon
Methinks you do not understand the problem. If you are doing laser ranging on a retroreflector, you get an absolute distance between the laser source and retroreflector. Easy problem! However, if you are trying to determine the (average) distance to a retroreflector on a pendulum moving in the plane of the laser beam, AND the laser is moving backwards and forwards independently, it becomes an insoluble problem unless you have an independent measure of the true position of the laser (satellite) so that you can subtract the motion of the laser.
Even GPS needs a fixed, independent receiver to get the high-precision, high-accuracy of what is called Differential GPS.
The whole ocean rising scam is their last line of defense promoting AGW after 20+ years of relatively stable land and sea temperature. The “we must act now” are cries of desperation because it’s obvious no one believes the warming narrative. The cries are getting louder, coming from more directions (Friday is childrens’ designated CC demonstration day now), and the propaganda increasing. Still CO2 in the atmosphere increases and we’re using more fossil fuels than ever. The UN sees their scam slipping away and after devoting so much time and energy (and our money) are worried. People are starting to question and that’s how this will all end. What they didn’t count on is the people’s unwillingness to lower their standard of living while others are allowed to increase theirs using the same logic.
The tide gauge data shows a constant rate of sea level rise, and the satellite data shows a different (higher) constant rate. The researchers concluded an increase in the rate of sea level rise by combining the two trends.
They trust the satellite data because it’s more technically advanced, and shows a higher rate. However, they still believe the tide gauge data for the period of prior to the sat data. Then for the period afterwards, suddenly that data is no longer trustworthy, for some unknown reason.
At some point, a clever engineer or scientist will figure out why the new method is returning errors, and the entire acceleration will go away.
That is why the “bathtub model” and global mean average should not be used … https://blogdredd.blogspot.com/2019/03/countries-with-sea-level-change-3.html … it obscures the current and future reality.
UN = “U No tell truth.” (i.e., liars and sophists)
Steve O
“The tide gauge data shows a constant rate of sea level rise…”
Where did you deduce this statement from?
I know of two tide gauge datasets:
– Church and White
– P(S)MSL
For 1880-2013, C&W data shows 1.8 mm/yr, and 3.6 for 1993-2013.
As the two authors communicated about their will to integrate altimetry data into their own series, everybody thinks of course that the C&W series didn’t start to raise before sat data came along.
This is a wrong assumption. I tried to make it visible by letting Office compute a sequence of 5-year distant linear estimates out of C&W’s data, all ending in 2013:
https://drive.google.com/file/d/1n3gyDRgvK5kbYkA1SymZfSMW5Cpw0tc4/view
I hope you’ll agree that this has few in common with a ‘constant rise’, even long time before the sat period.
Actually, I’m doing some little layman work on PMSL in order to compare it with sat altimetry:
https://drive.google.com/file/d/165M66btxeC5apsmo-h3XNgCBB4S_rEGI/view
Both time series show the same linear estimate (3.2 mm/yr). That the PMSL estimate is below C&W’s for the sat period shouldn’t wonder: the one reflects layman’s simple-minded raw data processing, the latter huge experience with tide gauge data evaluation.
In the historical tide gauge record, are there decadal periods of accelerated/decelerated SLR? Might our focus on the period beginning 1993 warp our perceptions of SLR acceleration?
Dave Fair
“In the historical tide gauge record, are there decadal periods of accelerated/decelerated SLR?”
Didn’t you access the first link in the comment you replied to?
Many commenters are carelessly using the word “accuracy” when they should be using the word “precision.” One can have a very precise measurement that is actually very wrong, such as when there is a very large systematic error or bias that has not been identified. Alternatively, making ‘corrections’ that are wrong will result in a very inaccurate result, regardless of how many significant figures are shown. Related to these issues of accuracy are unstated assumptions such as knowing the altitude of the satellite with perfect accuracy and precision.
Clyde Spencer
I know: you tell us the same stuff since years.
BUT… you never managed to show us the exact difference between the two – especially when measurements like laser ranging are concerned, a technique now used since 40 years.
YOU are the one who should give us a scientific proof of this method showing a lack of accuracy… and not the inverse.
Bindidon
I suspect that there may be an issue of English being a second language for you. If my article,
https://wattsupwiththat.com/2017/04/12/are-claimed-global-record-temperatures-valid/
is not clear to you, I might suggest that you go to Wikipedia,
https://en.wikipedia.org/wiki/Accuracy_and_precision
If the topic is available in your native language.
Accuracy and precision
https://www.google.com/search?q=accuracy+and+precision&client=firefox-b-d&tbm=isch&source=iu&ictx=1&fir=WstXoHtlyUq-RM%253A%252C2FCb1UhLUm9YoM%252C%252Fm%252F0bjjd&vet=1&usg=AI4_-kTUip80CQyUFZLh7w0AEjPagIKh9w&sa=X&ved=2ahUKEwizl5-E8ajhAhXjkOAKHXUCAY8Q_h0wHXoECAwQDA&biw=1407&bih=939#imgrc=WstXoHtlyUq-RM:
Jesus…
GregK
&imgrefurl=https%3A%2F%2Fsimple.wikipedia.org%2Fwiki%2FAccuracy_and_precision&docid=GtkhhTSTYA1uwM&tbnid=v9fnWW6dAjM1IM%3A&vet=10ahUKEwiRz4KmwqrhAhVCKKwKHfxmDx0QMwiwASg8MDw..i&w=1200&h=646&client=firefox-b-d&bih=912&biw=1336&q=accuracy%20and%20precision&ved=0ahUKEwiRz4KmwqrhAhVCKKwKHfxmDx0QMwiwASg8MDw&iact=mrc&uact=8
Targets make for a good visual example, and I have used the analogy myself. However, for things like temperature and SL, illustrations using a probability distribution along a line, such as the following, are better:
As with climate vs. weather, the only useful information re sea level is the tide gauges. Both weather and tide can be measured with sufficient accuracy to predict the local conditions for the near future. The longer we measure them the more accurate are our predictions. However, there is a time limit, beyond which we can only speculate. Even the IPCC admits this by referring to projections rather than of predictions.
Global climate and global sea level are different. Even after spending billions of dollars studying both (I can’t call it ‘research’), the only thing we have learned is that both systems are just too complex to model in the foreseeable future. My guess is that the gravy train is just too enticing to admit it.
Joe Crawford
“…the only useful information re sea level is the tide gauges.”
You are right. The altimetry period is a bit short in comparison.
But… by how much, do you think, do the two differ within their common lifetime?
so…. .145 inches.
oooohh scawy….
Hey MODS the last five (5) days I have received the old ” CAN’T DISPLAY THE PAGE” message, every time I try to access WUWT. Use DuckDuckGo
Hey now in a window I get the message “WEBSITE APPEARS NOT TO BE VALID”. I hit the Fix Connection Button and got on to leave this additional message. You should have a word with Word Press and have them talk to Microsoft.
I better rush to re-hem my flood pants or resole my shoes to be ready for the rising waters.
Here is Brooklyn, NY gauge. I know of no subsidence or up lift for this location and it’s current
https://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?id=8518750
Oops should have said the Battery tip of Manhattan
MIKE MCHENRY
The Battery
Trend 1895-2018: 3.0 mm/yr.
Trend 1979-2018: 4.3 mm/yr.
Imagine just one moment you would live here:
https://drive.google.com/file/d/1-2OcxjLuDVElTtnRn1ORIUp1Fvuc_tGa/view
What would you think about sea level ‘rise’?
What was the 1925 to 1945 trend in SLR, Bindidon?
Dave Fair
“What was the 1925 to 1945 trend in SLR?”
According to C&W:
1.7 mm/yr.
P.S. Somewhere upthread you were thinking of some possible cyclic behavior within SL data.
Here is a detrended variant of C&W:
https://drive.google.com/file/d/14StX8gooDpkKZa4OLnmldeTBN5rayTu7/view
If there was such a behavior, for sure we would see it right here.
Quebec probably experiencing glacier rebound
NOAA Technical Report NOS CO-OPS 065 report “Estimating Verical Land Motion from Long-Term Tide Gauge Records” of May, 2013 says The Battery Gauge (8518750) subsidence rate based on 151 years of data (to 2006) is 1.22 mm/yr. They also calculated subsidence/vertical uplift for about another 120 U.S. stations. Check it out.
I would suggest that the author Mr. Eric Worrall of this article check empirical data collected at tide stations with instruments in the ocean not radar data from a satellite orbiting the Earth. See “tidesandcurents.noaa.gov” Check San Francisco, California Tide station 9414290 mean sea level data from 1897 to 2018 presents sea a level trend of 1.96 mm/year which is equivalent to a change of .64 feet in 100 years.
3.7mm is a hair more than 1/8 of an inch. Seriously?
Get a grip UN. I expect not even the biggest twit at the UN could figure out how to drown in a 1/8 of an inch of sea water.
If you stood your entire live at the edge of the ocean, and were too stupid to get out of the way, you’d die of old age before the water reached you knees.
Quite honestly, any human being that can’t cope with such a small annual change will be eliminated from the evolutionary chain long before sea level change gets to them. They will be carried off by a hord of locust or a plague of frogs.
Assuming that the U.N. has got it right and that its asserted rate of sea level rise represents a real danger, why is no-one — even here — concerned with the problem of extracting the anthropogenic contribution from the natural one?
To the extent that the rise is natural, it would seem appropriate to take adaptation measures while humanity reforms its behaviour to address its part of the problem.
Has ANYONE managed to determine a believable apportionment of natural and anthropogenic forcings?
In the absence of such an apportionment, why must we be so committed to the sackcloth-and-ashes approach?
In 150 years (or 300 years) what technological advancements will be available?
If we look back 200 years for a comparison, even assuming no acceleration into the future, what can we expect? It will be surprising.
I think nuclear exchanges and the advanced weaponry we read about are much bigger problems.
Michael Mann’s estimate of SLR by the end of the century:
https://youtu.be/HdoItL_xJLo
I’m not great with math but I think he’s outside the consensus here.
was that 6 to 8 feet or 68 feet?.. guess it don’t matter, either is enough to drown him in.
6 to 8 feet. A total of 2133mm. SLR would have to be 26mm per year for the 82 years from the time of that video to 2100 to get to 7 feet.
That will be the Statue of Liberty gone then….
I remain skeptical that they can even measure sea level that closely.
How about some reading?
https://www.aviso.altimetry.fr/fileadmin/documents/data/tools/hdbk_j1_gdr.pdf
Gawd, Bindidon, do you even read the references you post?
The specifications: +/- 4.2 cm, up to +/-5.2 cm at one standard deviation. The number of adjustments, including humidity, is mind-boggling. Guesses at 1 mm accuracy is beyond belief.
Lets change our society, economy and energy systems based on UN IPCC guesses about future changes to multiple climate metrics, including SLR.
Before reading documents such as this I try a quick series of searches to try to reveal how close to reality the observations will be. Revealing. Try “assum”, “approx”. “adjust” and then be astonished by the result for “correction”.
Bindidon
While a little out of date, it is an interesting document. It claims “Each measurement of sea level shall have an accuracy of +/-4.2 cm for the GDR products and 5.2 cm for the IGDR (1 standard deviation) over 1 second averages for typical oceanic conditions of 2 m significant wave height and 11dB sigma-naught. This error budget includes the altimeter noise, uncertainties in corrections of atmospheric path delays, sea-state related biases, and orbit error.” However, it also says, “It [DORIS] includes a dual beacon receiving capability and an on-board real time function … to compute the orbit ephemeris with an accuracy of 30 cm (1 standard deviation).” It seems to me that it is a stretch to get 4.2 cm SL accuracy when the orbital ephemeris only has an accuracy of 30 cm! Further, that ephemeris appears to be derived from land-based lasers, so the orbital behavior is less well constrained over the oceans, where there is no secondary calibration.
“Trust, but verify.”
Probably the source of the 3.7 mm sea level rise of 2018 is https://climate.nasa.gov/vital-signs/sea-level/. One can get the data of the graph. I made this picture of the sea level evolution from 2016 to 2018, based on these data.
http://users.skynet.be/fc298377/Climate_nasa_graph.gif
In the year 2016, the average sea level was 44.69 mm (my calculation). The max was 47.2, minimum was 42.16. Difference between max and min: 5.04 mm.
2017: average 46.09 mm; max 50.24; min 42.51; difference: 7.73 mm. The difference between average 2017 and 2016 was 1.4 mm. In 2017, there was a significant rise but also a remarkable decrease of the sea level.
2018: average 50.03 mm; max 53.77; min 47.03; difference: 6.74 mm. The difference between average 2018 and average 2017 was 3.93 mm, due to the almost steady rise during 2018.
But the average rise of the sea level in 2015 was 10.69 mm more than the average rise in 2014! So, 2018 is certainly not exceptional regarding the acceleration of the sea level rise.
In each case, we have to follow carefully the new data!
Rik Gheysens
Thank you / dank U wel / merci for the NASA link. I confess that I was too lazy to download the most recent sat data (U Colorado’sat series actually goes only till Jan 18).
Anyway, the goal was not for me to have a look at the last 12 sat months but rather to compare an own processing of the raw PSML gauge data with the entire sat period (I chosed the data column without GIA adjustment):
https://drive.google.com/file/d/1BwiiYbbACIwwmo4av9KiWrG02iVfbcho/view
The two series differ in linear estimate by 0.1 mm/yr. Sat data shows much more homogeneity (‘skeptic’s love to say the data has been ‘tortured’).
Of interest is moreover that while NASA publishes an estimate of 3.3 mm/yr, Office shows only 3.0 mm/yr.
This of course isn’t a reason to doubt about the correctness of NASA’s data: Excel’s and Libre Office’s estimate functions for example do not account for autocorrelation in time series, let alone would they accurately handle very short time intervals, which in most cases show much higher standard errors than longer ones.
Conversely, Church and White’s tide gauge analysis shows a higher estimate for 1993-2013 (3.6 mm/yr) than does PMSL.
This, again, is no reason to think that C&W’s analysis gives us an exaggerated estimate! The difference rather is that between simple layman’s work and decades of experience in the field.
The following résumé is of my, as yet unpublished, paper entitled “Accelerating Sea Level Rise – Reconciliation of Tidal Gauge Readings with Satellite Data” by Dr Alan K Welch FRAS FBIS. It summarises an investigation into the two large sources of historic sea levels, namely Tidal Gauge and NASA Satellite databases.
The summary of this paper, reproduced below, shows what was covered and the two graphs below are copies of Figures 8 and 22 from the paper with added explanatory annotation.
WARNING – The figures may not appear, as happened when I sent a similar comment to Climate Etc. Also if they appear the labels may be misplaced due to being a Word produced from the original Excel file. The formulae can easily be input to Excel to show the trends.
Summary
“The tidal gauge sea levels follow quite closely a constant accelerating curve. Closer analysis also shows that by combining this curve with a long-period (57 year) sinusoidal function many aspects of the tidal gauge data are even more accurately portrayed. A combined equation of the form
y = (0.0063×2 – 0.2452x + 174.82) + 6sin(((50+2t)/57) π)
was derived, where t is now defined as 1800 being t=0. See figure 8 and Appendix 2. This equation was then used for short and long-term projections. During this study other possible formulae to replace the constant acceleration were also investigated.
A separate study of the NASA satellite results was also carried out when the deviation from the linear regression line was used. This arrived at a similar short-term (22 year) sinusoidal variation resulting in a combined equation given by
(3.225x – 37.377) + 3.5sin(((5+2t)/22) π)
See figure 22. Short term projections were carried out.
The 2 periods of 57 years and 22 years could be related to known ocean oscillations.”
The first graph displays: –
– The average annual Tidal Gauge Readings (red dots)
– Best fit Quadratic Curve (dotted green line)
– Combined Curve (blue line)
The combined curve picks up the following features absent in the quadratic curve: –
– The low slope (0.5 mm/year) around 1920
– Two periods of increased acceleration around 1930 and 1990
– The almost constant slope (3mm/year) during the period of the Nasa Satellites
– Deacceleration periods around 1910 and 1970
– The start of a new deacceleration period
Main predictions are
1. Reduction of slope down to about 2mm/year by 2030.
2. Slope reaching 3.7mm/year around 2060.
3. Sea level about 250mm above 2018 levels by 2100.
It can also be concluded that the basic Quadratic Curve, being based on a nearly 140-year period, is probably a true indication of the process taking place and the limited extrapolation to 2100 is more acceptable than any based on the 25-year NASA Satellite readings. The Quadratic points to a constant acceleration, which in turn points to a constant “Driving Force” what ever that is, but to remain constant over such a long period of 140 years points, in my mind, to a mainly natural cause.
The second graph displays: –
– The NASA results (blue line)
– Best fit Straight Line (dotted green line)
– Combined Curve (red line)
The combined curve shows a better fit at each end than the equivalent quadratic fit. The latter would extrapolate to much higher values by 2100. The post 2018 extrapolation points to a reduction of the slope over the next 10 years but any further extrapolation is judged questionable at this stage as the long-term findings of the Tidal Gauges must also be taken in to account.
Each combined curve contains a sinusoidal element that may be the result of the methods used in obtaining the readings. The Tidal Gauge readings have a sparse coverage and would be affected by the known “60 Year” Oscillation. Allowing for all the various ocean amplitudes and phase differences could easily result in the +/-6mm perceived oscillation. The NASA readings do not have a 100% coverage and known 20 to 30-year ocean oscillations, such as the PDO, could easily lead to a +/-3.5mm added variation.
The main conclusions are that the Tidal Gauge results are a good indication of the changes in sea level. The additional sinusoidal variations are consequences of the method of measurement and coverage. This all points to a possible additional 250mm rise by 2100. If anyone is interested in viewing my paper, I can be contacted on alankwelch@gmail.com.
Alan Welch
There is a lot to write about your comment, but I’ll restrict it to your sentence:
“The additional sinusoidal variations are consequences of the method of measurement and coverage.”
My answer is that
– you can artificially construct a set of sine waves out of any curve;
– sinusoidal variations are above all a consequence of the method of evaluation.
Too many people consider time series spatially and temporally as homogeneous data sets.
That leads per se to ill-born evaluations despite a wonderful marriage of ‘accuracy’ and ‘precision’, because some regions and periods then become unduly overrepresented.
The most typical example is that of temperature measuring stations. Whichever record is chosen: about 50% of stations are in the US.
Not considering any spatial weighting automatically results in the Globe looking like the backyard of the United States.
My understanding is that the weightings are an attempt by the data-wranglers to account for that.
Dave “Fair” (?)
One of my teachers told me over 50 years ago:
“The more ignorant a person behaves, the more quickly s/he will be ready to discredit and denigrate other persons and their work.”
Be sure I’m proud to be named a “data-wrangler” by people like you.
Who are those being discredited and denigrated by my using a lighthearted shorthand for the various worldwide groups dealing with weather data?
Bindidn
Thank you for your comments
What you describe is Fourier Analysis and, yes, you can fit any set of waves as close as you require to get better and better fits.
But my approach was to use the best fit curve, in the case of the Tidal Gauges, a 140 year quadratic, and then look at the residuals between that and the actual results . This showed up a roughly 57 year cycle which I thought was significant. I didn’t take it any further.
The combined curve then revealed many significant features of the actual readings which my figure would have shown if only I could find away of adding to my comments.
Can anyone tell be how to add figures to these sort of comments?
Finally, as I indicated, I will E Mail (alankwelch@gmail.com) the full text to anyone so they can judge better if what I write is “a sinusoidal curve too far!” or has some significance.
Alan Welch
Thx 2u2
“Can anyone tell be how to add figures to these sort of comments?”
Simply add a link to them.
In earlier times, links ending with a picture file type were automatically expanded online; but actually, only a handful of ‘special guests’ enjoy this privilege.
I don’t see how you manage to detect any cycle within the data, the one over the whole period of course excepted.
Please upload your document and associated Excel stuff by using e.g. Google Drive like I do all the time.
Blididon
Thanks for your advice
Will try to add links to my paper (PDF) and 2 pictures via Google Drive
https://drive.google.com/file/d/1e89LBXsZAqAJfmAQb7wNXVpddKZK7j-y/view?usp=sharing
https://drive.google.com/file/d/1UfuXDp1-bxLC5rzw7gapSXRqhMuJTGx3/view?usp=sharing
https://drive.google.com/file/d/1vlFt1nPRREGsh_5qvYEunOLJoMBdIYqA/view?usp=sharing
As shown in the paper the 57 year cycle showed up in the residuals and judged by eye and was not via any mathematical curve fitting. As such it is indicative to a possible extra component of the Tidal Gauge readings as shown in the figure Appendix 2.
Likewise for the 22 year cycle for the NASA results. I admit this is less obvious but the approach was followed as a possible alternative to the Nerem et al quadratic fitting and subsequent extrapolation to 2100 which I think can not be justified with only 25 years worth of readings followed by over 80 years of extrapolation.
Please indicate if files picked up OK.
Again many thanks for your useful advice.
It says that the average over the satellite altimetry period (since 1993) is 3.15+/- 0.3 mm with an acceleration of 0.1mm/yr.sqrd
Their slr statement and some critical commentary appear in para#4 of this document.
https://tambonthongchai.com/2019/03/31/wmo/
Oops para#12
“The findings in the group’s annual State of the Climate report will bolster efforts by António Guterres, the UN secretary-general,”
___________________________________________________
Doesn’t the UN have problems enough with
– unsolved remains from Balkan wars
– Hutu / Tutsi drama Ruanda; Kongo; Uganda
– Baltic states fearing aggression from the east / high self-esteem: who is willing to waste time with the Baltic states neither able nor willing to pay their NATO dues
– unsolved malaria problems
– Ebola
– Biafra children starving to death since 60 years while their corrupt “statesman” have thick bank accounts overseas, not at least in the U.S. that contributes to that accounts
– etc.pp.
“Sea Level” referenced to what immobile standard, exactly? I’m honestly curious.
Everything on, in, and around the planet is constantly moving by inconsistent amounts, if I remember my geology properly.
What standard of reference could possibly be used to provide millimeter-level precision when measuring the average surface level of ~326 million cubic miles of water sloshing around in an unevenly-shaped ‘container’ of near-fractal boundary complexity, that is constantly changing shape in frankly immeasurable ways, with plate movements in the centimeters per year range?
I find it impossible to conceptualize such a measurement having any validity at that level of precision.
Can someone explain how it is possible to take this measurement without requiring assumptions many orders of magnitude greater than the reported result?