Friday Funny – sea level rise is “set to flood UN headquarters as soon as 2100” – another self-immolation by Zoë Schlanger

While we can only hope this is true, and hopefully the flood will finally get the U.N. out of the U.S., the reality is much different.

From this article at QZ back in September, which I missed.

Sea level rise will flood the neighborhood around the UN building with two degrees warming

Leaders are gathering at the United Nations headquarters in New York City this week, where a set of climate change meetings will take place alongside the United Nations General Assembly. While they discuss ways to prevent the worst effects of climate change, the neighborhoods around the UN face a very real threat: Sea level rise is set to flood the immediate area, possibly as soon as 2100.

Right now, of every US city, New York City has the highest population living inside a floodplain. By 2100, seas could rise around around the city by as much as six feet. Extreme rainfall is also predicted to rise, with roughly 1½ times more major precipitation events per year by the 2080s, according to a 2015 report by a group of scientists known as the New York City Panel on Climate Change.

But a two-degree warming scenario, which the world is on track to hit, could lock in dramatic sea level rise—possibly as much as 15 feet. Whether it will take 100 years or longer for the total extent of the sea level rise to play out is unknown, as the rate of ice melt at the poles is harder to predict than the amount of ice that can melt with a specific amount of warming. 

This model projection photo is provided with the article:

Map source: Climate Central

The article was written by one Zoë Schlanger who in my opinion, isn’t capable of writing about climate honestly – mainly because she willfully ignores facts that are plainly evident to anyone with a a shred of journalistic curiosity.

WUWT readers may recall I wrote this article about her journalistic failures: The journalistic self-immolation of Newsweek’s Zoë Schlanger

So in this QZ article, she willfully ignores the sea level data from about a mile away at The Battery on the tip of Manhattan Island, that is publicly available from NOAA:

The relative sea level trend is 2.85 millimeters/year with a 95% confidence
interval of +/- 0.09 mm/yr based on monthly mean sea level data from
1856 to 2018 which is equivalent to a change of 0.94 feet in 100 years.

Note that the trend is steady, there’s no acceleration seen in the data.

NOAA calculates 0.94 feet rise in 100 years for the graph. Since we have 80 years left to 2100, we’ll calculate 0.94 feet x 80/100 = 0.752 feet or about 8 inches by 2100.

That’s a far cry from six feet by 2100.

But for people like Zoë who can’t handle graphs, a picture says a thousand words. Spot the sea-level rise over the last 100 years:

114 thoughts on “Friday Funny – sea level rise is “set to flood UN headquarters as soon as 2100” – another self-immolation by Zoë Schlanger

  1. Sea levels 2-meters lower today than 3,000 years ago. Today’s mild thaw up out of the coldest era of the past 8,000 years the Little Ice Age…I expect Sun Cycles 24-27 to drop sea levels an inch or so….

    • I have often referred to the UN ignoring their own warnings.

      Here is my blog where I look into the UN with their recent spending and no attention to anything that may be in their policies.

      https://thedemiseofchristchurch.wordpress.com/2016/05/06/un-headquarters-and-usd1-2-billion-upgrade-and-rising/

      Like I say in the blog, “At least they could install a jetty or other such facility”, (to impress readers), even though it is evident the UN does not give rising sea levels any real credence.

      Cheers

      Roger

    • As a non scientist, but a curious guy who has been seriously looking at this scam, I have a serious question on sea level rise from the “melting polar ice caps”. Do ANY of the “scientists” claiming this sea level rise realize the the AVERAGE DAILY TEMPERATURE of the continent of Antarctica is 59 degrees BELOW ZERO F? How in H is 5 degrees of warming going to melt that block of ice?

    • I’d like to see the experiment whereby the delegates are placed in a tank with sharks to see what the effect of climate change might be if said delegates refused to leave the rising sea level.

    • Yeah. I don’t know if I can wait that long. The useless twats at the U.N. would be arguing whether or not to vacate the building until they drowned.

      Mods. Why don’t any of my posts-post? This is a constant issue.

      • It’s the same for everyone John, every comment gets before getting posted. And those with the wrong mix of words that offend the algos go to a moderation bin. Anthony announced a couple of weeks back WUWT will be moving to a register-to-post arrangement in the new year, to address these moderation and trroll issues.

    • They should relocate immediately – as per the precautionary principle they expect us to follow with their mindless “science”.

      P.S. and good riddance.

    • You have to worry that, if the UN floods, where does all the sewage that will be released from that building as a result, go? And I don’t mean what is in the lavatories.

    • I like this site, a lot, but every now and then a radical ‘right libertarian’ strain of political comments interfere with the ‘climate science’.
      I think people who hate the UN are silly, this is an imperfect organisation but the intent is good and there are many functions of the UN that are totally brilliant, such as the ITU and WHO.
      I personally find this strain of ‘USAmericans hating the rest of the world’ as exemplified by these sort of derogatory comments awful and it exposed the gross xenophobia that is the USA.
      Please, you are a tiny part of a gigantic global community, do not isolate yourselves, join in. In particular there is nothing special about USA or its people, you are all plain ordinary, like all the rest of us.

  2. We should play this up and advocate that Trump purchase the building and all support facilities for $0.10 on the Dollar value. The UN can then be relocated to Geneva where sea level rise won’t impact their structures.

  3. Just to be sure, as a precaution, the UN should relocate now. ASAP.

    I would support the US paying to relocate them to N. Korea, where they will be best able to reduce their carbon footprint.

  4. Who is this Zoë Schlonger, anyway?
    According to her map, it looks like Clinton, (Bill? Hillary?) and even young Chelsea will be drowned. I don’t suppose they’d have enough sense to walk up hill.
    Maybe that would be sad, but I’m not holding my breath.

  5. A discernible correlation between sea level rise and the UN, is evidence of a first-order forcing of [catastrophic] [anthropogenic] climate change. It may already be too late to debureaucratize the institution.

  6. Given the rate at which gargantuan, UN-sized bureaucracies operate, the UN might not have enough time to relocate before it’s too late. 😉

    • Given the increasing size of the UN and its parasites, isn’t that end of Manhattan in danger of tipping over?
      (I think Rep Hank Johnson of GA would be the one to answer that.)

  7. I once read an scientific paper that claimed that even if all the ice in Greenland melted, and that would add about 23 feet of sea level to the global ocean, that the local sea level around Greenland and northern Europe and norther NA wouldn’t go up at all and might even fall slightly, due to the gravitational attraction that the GIS plays on the local gravitational Geoid. The melted water would slowly migrate towards the equator, and then at some point would collect at the antipode of Greenland (on the opposite side of the planet) I wish I could find a link to that older scientific paper. I hope some smart folk here can elaborate if there is any truth to this.

    Sea level isn’t flat, as many of us here know. As measured from the centre of the Earth. For instance, the Pacific is about 18″ higher on the Pacific side of the Panama Canal than the Atlantic side, due to all kinds of factors including tides, currents, winds, salinity etc, but mostly gravitational geoid. It is a complicated equation for sure. But the alarmists assume the ocean is just a big bath tub and water in equals rising oceans everywhere. If this isn’t true, or even if the general principal is true I described above, then what we need to worry about in the northern hemisphere is Antartica melting, and not the GIS. And with an average temperature below -50 in Antartica, it ain’t melting anytime soon. It may even be acquiring mass which would then lower sea levels x2 in the northern hemisphere. Sea level scare tactics have to be the weakest of all, since as we see in the two pictures above, there isn’t much difference in sea level in the last 125 years. Nothing to be ‘alarmed’ about. But it is fascinating science, and I hope to learn more.

    • True, but the zone where sea level would sink does not extend as far as New York. the “zero line” is somewhere in Nova Scotia.

  8. It is very much en vogue and stylish these days for leftists to write scary articles like that, quite trendy. Imagine lying like that for a living and thinking you are doing some good some how because someone some where is going to…what…give up a nice life style and live in a mud hut? I doubt it.

  9. “This is what Catastrophic Sea Level Rise Looks Like” …

    I don’t see much sign of sea level rise from between those two photos, but I just noticed it sure looks like the Statue of Liberty used to be just black and white. Sometime after 1898 it acquired color. I was really confused about this but I found an explanation here:

    October 29, 1989 (from Scientific Progress Goes ‘Boink’, page 23 / The Indispensable Calvin and Hobbes, page 151)

    Q. How come old photographs are always black and white? Didn’t they have color film back then?
    A. Sure they did. In fact, those old photographs are in color. It’s just that the world was black and white then. The world didn’t turn color until sometime in the 1930s, and it was pretty grainy color for a while, too.
    Q. But then why are old paintings in color?! If the world was black and white, wouldn’t artists have painted it that way?
    A. Not necessarily. A lot of great artists were insane.
    Q. But… But how could they have painted in color anyway? Wouldn’t their paints have been shades of gray back then?
    A. Of course, but they turned colors like everything else did in the ’30s.
    Q. So why didn’t old black and white photos turn color too?
    A. Because they were color pictures of black and white, remember?

    So maybe CO2 is really responsible for the greening (and blue-ing and red-ing) of the planet?

    Science sure is wonderful.

    (Sorry, but I could not locate an image of that Calvin & Hobbes cartoon — it’s a classic).

  10. Anthony Watts

    1. It is imho evident that the lady’s article is based on global data, and not on that of the local tide gauge in NY.

    Sea level is a rather global affair; we cannot simply deduce the estimate for New York’s future solely from what its local tide gauge tells us.

    *
    2. “Note that the trend is steady, there’s no acceleration seen in the data.”

    Sorry, but this is not correct. You see no acceleration because you look at a linear estimate. Applying a quadratic fit to the gauge’s data would be the right way.

    Please download the gauge’s data, from NOAA or PSMSL:
    12; 40.700000; -74.013333; NEW YORK (THE BATTERY)

    enter it into a spreadsheet calculator and let the guy compute the trends for periods starting with e.g. 1900, 1950, 1980, and 1993 (the beginning of the sat altimetry period).

    You should obtain the following linear trends, in mm/yr:
    1900-2018: 3.04 ± 0.05
    1950-2018: 3.05 ± 0.11
    1980-2018: 4.23 ± 0.25
    1993-2018: 3.84 ± 0.47

    I suppose you will agree that if there was no acceleration, all trends would be nearly equal (like they indeed are for 1900 >< 1950), regardless the period's starting year.

    The tide gauge at 'The Battery' shows, for 1993-2018, a trend higher than the satellite altimetry data of both NASA (3.0 ± 0.04) and NOAA (2.87 ± 0.03 mm/yr).

    Rgds from Germany
    J.-P. D.

    • Thanks Bindidon, no one else on this site is capable of performing simple mathematics.

      Using your logic (and calculations): since the trend from 1993-2018 is less than the trend from 1980-2018, then you agree that sea level rise is decelerating?

      Further, let’s use your highest trend to evaluate the author’s catastrophic flooding scenario.

      4.23 mm/year x 81 years = 343 mm.

      Metric to Imperial conversion is too difficult for me. Does 343 mm equal approximately six feet?

    • “Sea level is a rather global affair”

      Not at all. It varies widely geographically depending on the reason for the rise:

      https://www.researchgate.net/profile/Jonathan_Bamber/publication/49608511/figure/fig4/AS:668403400458258@1536371197715/Relative-sea-level-variations-due-the-gravitational-and-Earth-rotational-effects-of-ice.png

      “Sorry, but this is not correct. You see no acceleration because you look at a linear estimate. Applying a quadratic fit to the gauge’s data would be the right way.”

      Only if you know that the sea level rise is a quadratic process. Remember, you can fit a quadratic to a completely random data set and get an “acceleration” (or “deceleration”).

      “I suppose you will agree that if there was no acceleration, all trends would be nearly equal (like they indeed are for 1900 >< 1950), regardless the period's starting year."

      No, because the acceleration might instead be in subsidence, not in sea-level rise. Which seems likely as Sandy Hook GPS recorded a subsidence of 1.83 +- 0.29 mm/year in 1995-2006:

      https://www.sonel.org/?page=gps&idStation=1895

      but 2.65 +- 0.26 mm/year in 2006-2017:

      https://www.sonel.org/?page=gps&idStation=1896

      Which suggests that the absolute sea-level rise is fairly steady at about 2 mm/year, in New York as elsewhere.

    • Yeah… not exactly. Did you notice that in December of 2008 sea level DECLINED and did so several times over the next few years yielding a recent trend over the last decade of essentially ZERO? It all depends on when you start and end your analysis. Over the entire record, there are brief periods of acceleration followed by deceleration and sea level decline. The overall, long term trend is the best trend for estimating future sea level rise and it stands as posted, 2.85 mm/yr.

      • stinkerp

        “Over the entire record, there are brief periods of acceleration followed by deceleration and sea level decline.”

        That’s evident, stinkerp!

        This is the reason why you have to take numerous gauges into consideration, and to build an average of their (VLM corrected) data.

        See replies to tty and Pillage idiot for data and graphs.

          • Remember that when the “biggest piece of ocean in the world” is not rising [falling, actually] then the chance of world SLR is pretty remote.

            And when the world’s tide gauges have not had long term GPS chips on them, they are not a counter argument.

            Fort Denison, BTW, is sinking slightly, making current MSL even lower.

          • spangled drongo

            “Remember that when the ‘biggest piece of ocean in the world’ is not rising [falling, actually] then the chance of world SLR is pretty remote.”

            Falling actually? Sure sure?

            I hope you at least did not deduce that from the one Fort Denison station!
            If you didn’t : where then did you get that from?

            Don’t tell me you got it from (No?)TricksZone:
            https://tinyurl.com/u8n7h5s

            This info is based on 100+ year gauge stations, i.e. exactly ten for the whole Pacific! Ten of over 250 available Pacific PMSL sites (330 at U Hawaii), of which over 100 remain when you exclude those which couldn’t contribute to the reference period I use (1993-2013).

            *
            “And when the world’s tide gauges have not had long term GPS chips on them, they are not a counter argument.”

            You can’t simply pretend that. You have to scientifically contradict the VLM corrections applied by using the nearest GPS station(s) around the gauges.

            Here are all PMSL stations you can obtain for the Pacific (from 50N down to 60S, and from 145E to the coastal line of North/South America:

            https://drive.google.com/file/d/1Tm_hpC1oRBdShSjJ-wBo7w8kb2g9cuHR/view

            Here is a plot with as comparison Grant Foster’s data for the Globe (a more professional elaboration, with OLS-based anomaly construction):

            https://drive.google.com/file/d/1I2OygDuLhB_N0Ra5cOQfwXKzkCdC1q8R/view

            The red data has a higher trend, yes! But no: it is not due to the stations’ lifetime, but to my severe exclusion of stations unable to provide sufficient data for the reference period.

            Trend for 1880-2018: 2.2 ± 0.03 mm/year (like Jevrejeva, i.e. too high compared with Foster).
            For 1993-2018: 2.6 ± 0.12 mm/year (OK).

            So, sorry: no falling trend in the Pacific.
            Estimated acceleration since 1950: 0.03 ± 0.004 mm/year². Not very much!

            Rgds
            J.-P. D.

          • Bindidon

            First calculate how much Ft Denison is actually sinking. That will wipe out any “official” SLR there.

            “If you didn’t : where then did you get that from?”

            If you had been involved in sea front infrastructure and other marine construction, general observation etc. for over 70 years around the pacific, as I have, you would see evidence of current highest tides being up to a foot lower than they were in the ’40s and ’50s based on very accurate benchmarks that in turn were based on local council assessed, MSL benchmarks.

            You would see evidence of ocean-front homes that were being washed out to sea 50 years ago now changing hands for tens of millions.

            You would see evidence of ocean beaches with hundreds of acres of extra sand that just wasn’t there in those times.

            You would see evidence of surf board riders complaining that their favourite point breaks no longer work because today there is too much beach.

            When the evidence from Pacific atolls, and people like Nils Axel Morner who have spent lifetimes more specifically involved, agree with what I list above, world SLR based on conjured satellite altimetry, is something to be very sceptical about.

          • spangled drongo

            “First calculate how much Ft Denison is actually sinking. That will wipe out any “official” SLR there.”

            I can do that. But it’s now 3:15 AM at UTC+1…

            At the end of the Bothnian Gulf between Sweden and Finland, the gauges are raising, raising… 10 mm/year! That’s the reason why people evaluating sea levels actually use vertical land movement data based on GPS.

            *
            “… world SLR based on conjured satellite altimetry, is something to be very sceptical about.”

            Sorry: I didn’t mention sat altimetry anywhere.

            But the comparison of the two methods is as it is:

            1. 1880-2015
            https://drive.google.com/file/d/1QsWSiByU9jZONeW0ixkrocumRCPvIBWl/view

            2. 1993-2015
            https://drive.google.com/file/d/1v77IZgLwKsdob0YfgMQZVm6sS1AUKW1Q/view

            I have made a similar job, even if not so professional as theirs, and can only confirm their results.

            I hope you don’t belong to these strange people pretending that tide gauge data is manipulated worldwide since 1993 in order to give a fit to altimetry data…

            Rgds
            J.-P. D.

          • The fact that long term tide gauge data is consistent speaks for itself.

            But have you considered that when tide gauge data isn’t fully audited and corrected for vertical land movement that for the satellites to agree they would have to be somewhat fiddled with?

            Your graphs don’t show the “errors” of Envisat.

            The main thing people can do is pay attention to local HATs and sea fronts over long periods and the truth will eventually dawn on them.

            The most believable graph is a wet one.

          • spangled drongo

            “The fact that long term tide gauge data is consistent speaks for itself.”

            Consistent with what? What do you mean here?

            Anyway: like there is no perceptible difference between CONtiguoUS temperature data coming from the best, pristine USHCN and USCRN weather stations and all the 18000 around them, you might be surprised by this graph below, in which I compared the data of all available PMSL tide gauges with those having a lifetime of at least hundred years:

            https://drive.google.com/file/d/1UsJgaymQYMGiR1Vxc6cghgzBI5baeor0/view

            The trend and standard error differences are negligible. And this is a bit strange when you compare the 100y+ distribution with the rest:

            https://drive.google.com/file/d/1_XDvRE3E5qzy0vAgv2fli36wGYktiV1F/view

            “But have you considered that when tide gauge data isn’t fully audited and corrected for vertical land movement that for the satellites to agree they would have to be somewhat fiddled with?”

            Here you become really disingenuous. How can you pretend that?

            Look at the work made by Dangendorf & al., and please manage to learn out of it, instead of insinuating and discrediting.

            Good luck.

          • Bindidon

            Thanks for confirming the consistency in the long term tide gauges.

            But you feel that satellite altimetry also covers vertical land movement?

            Was that what Envisat was up to?

            Wow!

    • Bindidon,

      I don’t think you followed your logical chain to completion. Look at this from a purely Physics 101 perspective: our starting time and relative velocity are zero at 1900. By 2018, 119 years later, the velocity should be (we’ll use your rate for the period) 3.04 mm/y ±0.05mm. Since the graph is in meters, we’ll set the velocity at 0.00304 m/y.
      I believe the correct equation to use here is v=at. For delta v = 0.00304m/y and time t = 119y we have
      a = v/t = 0.00304/119 = 0.000025m.y^2 = 2.5E-5m/y^2

      That’s the acceleration that gives us a 3.04 mm/y delta v. But what kind of s curve do we have?

      If s = 1/2at^2, then s = 1/2 (0.000025 * (119^2) ) = 1/2(0.000025 * 14161) = 1/2( 0.354) = 0.177 m. That’s half the observed rise.

      It seems obvious that if the entire series from 1900 to 2018 is used to get the rate of 3.04 mm/y, the acceleration needed to get there in that time period does not produce the observed s, and the curve looks nothing like the straight line seen in the data plot.

      The plot of the Battery tide guage is not logarithmic; it’s just a straight s=vt plot, no more.

  11. Evacuate the U.N. immediately. Problem solved. I suggest Amsterdam, as much of that prosperous, highly productive, and well-populated country is already below sea level.

  12. Six feet = 1,829 mm, so that sea level rise between now and 2100 would have to accelerate to 22.9 mm/year, about 8 times faster than the average sea level rise rate at the Battery over the last 170 years.

    But if Zoe Schlanger wants to prove her point, let’s send her on a one-way trip to Greenland with a blowtorch, and see how much ice she can melt over the next 80 years.

  13. It looks possible that in the next century or two the world will lose the ability to power its cities and that they will descend into ruin, therefore sea level rise will be of little consequence. It is a choice of sinking into anarchy sooner or later and my choice is to put it off for as long as possible. Making full use of uranium in nuclear power stations would help to keep civilization going as long as possible, hopefully buying us enough time to get nuclear fusion to work. What is the maximum amount of nuclear power stations that it would be sensible for the planet to have to make best use of uranium ? Ideally how many 2 GW nuclear power stations should be built ?

    I watched Youtube video , “Bill Gates on AI, Climate, Carbon Tax, Nuclear Power, China” from November 21st 2019. Bill Gates talked with Bloomberg Editor-in-Chief John Micklethwait at Bloomberg’s New Economy Forum in Beijing. He thought present design nuclear power stations were noncompetitive and too prone to human error. How can people who think climate catastrophe is likely turn round and complain that nuclear power is too expensive ? Is it actually wisest to mostly rely on gas power stations for the next few decades while gas from fracking is abundant & cheap then switch to more nuclear power later ?

    • Alex

      “What is the maximum amount of nuclear power stations that it would be sensible for the planet to have to make best use of uranium ? Ideally how many 2 GW nuclear power stations should be built ?”

      I don’t go here into the tremendous waste problem caused by nuclear plants during electricity production and upon dismantling. All over the world, the waste remaining after fuel rod reprocessing, and all decommissioned plants still await final solutions.

      Here is a paper discussing that (it is dated 2011).

      https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6021978

      He thinks that 15000 (fifteen thousand) 1 GWel nuclear plants would be necessary to get rid of fossil fuel use.

      This of course doesn’t mean to simply get rid of it within the current electricity production, but to get rid of ALL fossil fuel use, including worldwide traffic etc etc.

      According to a BP study, Mankind consumed around 14 billion oil units or 160 petawatthours of energy in 2018. 80 percent of this was covered by burning fossil fuels such as coal, oil and gas.

      “… hopefully buying us enough time to get nuclear fusion to work.”

      It’s a bit hard to be optimistic here:

      – we currently can’t implement nuclear fusion other than using the deuterium/tritium mix: that means breeding tritium out of lithium in blankets, and very aggressive neutrons;

      – research and development on the tokamak system started around 1957, the current prototype ITER is far away from working, won’t do much more than solving the plasma containment problem, and its successor DEMO, thought to integrate the tritium breeding blanket management, is not expected to present results before… 2080.

      Hmmmh.

  14. Sea level changes on the east coast of the USA are also caused by the same forces that speed up and slow down the Gulf Current that moves northward near the coast. Local sea level changes are not a trivial problem.

  15. In the immortal words of John Mc Enroe ‘‘ they cant be serious !!’’
    Insane predictions just keep coming & coming with no reference nor mind paid to what real world geological data has & is continuing to tell us….
    Never mind the facts….

  16. Were there not predictions by Hasen that NY, and also the home of “Real Climate”, to be under many feet of water 20 years ago?

    • As Neal Gaiman once wrote about an english housing development:

      “Everybody agrees that the only sensible thing is to blow the whole thing sky high, but the residents thinks it should be evacuated first”

  17. As a non scientist, but a curious guy who has been seriously looking at this scam, I have a serious question on sea level rise from the “melting polar ice caps”. Do ANY of the “scientists” claiming this sea level rise realize the the AVERAGE DAILY TEMPERATURE of the continent of Antarctica is 59 degrees BELOW ZERO F? How in H is 5 degrees of warming going to melt that block of ice?

  18. The problem with the NASA satellite readings and their interpretation is that 27 years is too short a period in which to ascertain a plausible acceleration. The Tidal Gauge readings cover well over 100 years and their pointing to an acceleration of about 0.012 mm/year2 could be judged as a serious correct figure. The figure of about 0.09 mm/year2 as derived in Nerem et al, 2018 can be shown to be due to the methodology used and not inherent in the data set. It is this level of acceleration that leads on to many of the extreme sea level rises banded around by alarmists, papers and TV.
    The following is a step by step showing why the high accelerations are false.
    Step 1 is to apply a linear fit to the satellite readings.
    https://drive.google.com/file/d/1rJUTVNYhB7oM73sBURE5yffiFgUxCZzf/view?usp=sharing
    resulting in a rise of sea level of about 3.3mm year.
    Step 2 is to fit a quadratic
    https://drive.google.com/file/d/1I9uJi3bqG2QAvluCS-1J_J6O3bC20fwe/view?usp=sharing
    resulting an acceleration of nearly 0.1 mm/year2.
    Step 3 fits the linear fit plus a sinusoidal variation of 3.5mm amplitude and 22-year period.
    https://drive.google.com/file/d/1aOrEk_X3YW_BxW3wM8f4-AN445cHaVjn/view?usp=sharing
    showing just as reasonable fit as the quadratic.
    Step 4 is to generate a set of data based on the linear plus sinusoidal equation and to fit a quadratic curve.
    https://drive.google.com/file/d/1hgVSmISXHZ_DH3eFHOCtcC76sZL-sa3u/view?usp=sharing
    resulting in an acceleration of 0.0844 mm/year2, not much smaller than that obtained by in the original Nerem approach.
    Finally, the 2 approaches are shown on a plot of residuals, these being the difference between the actual reading and the linear line.
    https://drive.google.com/file/d/1l1izgwQZEhseNuO3c4BP4R8zL3sFpD6E/view?usp=sharing
    Inspection of these 5 plots indicates how the high predicted accelerations are consequences of the method and that the Tidal Gauge values may be more indicative of the long-term behaviour.
    If the satellite readings had started 11 years earlier then after about 25 years we could have been looking at a just as false deacceleration and alarmists raising Hell about a new Ice Age.

  19. Commenter alankwelch presented above some thoughts which in my opinion are
    – unnecessary complicated
    and
    – manifestly incorrect.

    Neither is the sat period ‘too short a period in which to ascertain a plausible acceleration’, nor is it correct to say about the tide gauges that their ‘acceleration of about 0.012 mm/year2 could be judged as a serious correct figure’ when we compare them to altimetry’s acceleration.

    There is absolutely no need to bring into play some ‘sinusoidal variation of 3.5mm amplitude and 22-year period’.

    *
    It is perfectly sufficient to compare apples with apples, instead of comparing apples with oranges, and to introduce a posteriori some artificial and redundant orange-apple converter.

    And that we can do by comparing (linear or quadratic) tide gauge trends with sat trends within the same period as that of sat altimetry.

    We can’t compare tide gauge trends and accelerations computed for the period 1880-2018 with altimetry trends and accelerations computed for the period 1993-2018: that makes no sense at all.

    Here is a graph showing two different evaluations of the PMSL tide gauge data set (Dangendorf & al. for the period1900-2015; Foster for 1880-2018), together with NOAA’s sat altimetry (for 1993-2018):

    https://drive.google.com/file/d/1QsWSiByU9jZONeW0ixkrocumRCPvIBWl/view

    Dangtendorf’s time series manifestly is the result of a very intensive homogenisation work, whereas Foster’s has a rawer character with much higher deviations from its mean (which nevertheless is very near to Dangendorf’s).

    Linear trends for Dangendorfs and Fosters common historic tide gauge period (1900-2015), in mm/year:
    – Dang: 1.40 ± 0.01
    – Foster: 1.43 ± 0.01

    Linear trends for Dangendorfs, Fosters and NOAA’s common sat era period (1993-2015):
    – Dang: 2.80 ± 0.02
    – Foster: 2.89 ± 0.08
    – NOAA: 2.72 ± 0.03

    And finally we see a chart showing, for their common sat era period, the three time series, with their respective quadratic fits (2nd order polynomials) computed and drawn by the spreadsheet calculator:

    https://drive.google.com/file/d/1v77IZgLwKsdob0YfgMQZVm6sS1AUKW1Q/view

    We immediately see that the polynomial curves and the quadratic coefficients for the two tide gauge series and the sat series, and thus their respective acceleration factors, are nearly identical.

    Rgds
    J.-P. D.

      • Thank you for your comments and the very useful data sets and graphs you supplied. I agree that the comparisons over the period 1993 and 2015 show the same trends, although the accelerations derived from the 3 formulae do vary between .0614 and .0984 mm/year2. These figures are the coefficient of the square term multiplied by 144 as I believe you worked in mm and months x=0 being the start of 1993.
        Having said that I still feel the approximate 25 year period is still too short when decadal oscillations or part of decadal oscillations may be playing a role. In the paper “Is there a 60-year oscillation in global mean sea level?” by Don P. Chambers,1Mark A. Merrifield,2and R. Steven Nerem they quote “Until we understand whether the multi decadal variations in sea level reflect distinct inflexion points or a 60-year oscillation and whether there is a GMSL signature, one should be cautious about computations of acceleration in sea level records unless they are longer than two cycles of the oscillation or at least account for the possibility of a 60-year oscillation in their model. This especially applies to interpretation of acceleration in GMSL using only the 20-year record of from satellite altimetry and to evaluations of short records of mean sea level from individual gauges.”
        The point in introducing a small sinusoidal variation was to show how easily a variation like this could result in the higher accelerations as obtained by Nerem et al, 2018 when no long-term acceleration is present.
        I covered a lot of this in my paper
        https://drive.google.com/file/d/17lXnNtsLSlzSOx7tRvbDPwYMDibpvXKG/view?usp=sharing
        which I hope now is void of earlier typos. The appendix 2
        https://drive.google.com/file/d/1UfuXDp1-bxLC5rzw7gapSXRqhMuJTGx3/view?usp=sharing shows the influence of a 60 year-ish decadal oscillation as is also shown in the paper by Dangendorf & al you listed.
        As its now DEC 23 I wish you a merry Xmas and all the best for 2020.

        • alankwelch

          Thank you so much in turn for this convenient and constructive reply.

          I agree with you in all visible points, and will certainly have some closer look at your paper.

          Merry Xmas / Frohes Fest / Joyeux Noël

          J.-P. D.

        • I forgot to mention a little detail. You wrote above

          “I agree that the comparisons over the period 1993 and 2015 show the same trends, although the accelerations derived from the 3 formulae do vary between .0614 and .0984 mm/year2.”

          Correct. But did you notice that these accelerations contradict your comment, as the least one is NOT that coming from tide gauge data but that obtained out of altimetry data?

          Of course we agree: the difference is very small, but that is exactly what I’m happy to see you confirming.

          Tide gauges and altimetry work hand in hand, and only dark-minded Pseudoskeptics will pretend that tide gauge data is ‘adjusted’ to have it near to that ofr altimetry.

          cu

  20. I advocate that the UN leaves NY immediately to make sure they avoid the flood. Suggested alternative site is Lagos. Lets see the virtue signalling from there

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