Sea Level Trends Nearly Constant For The Past 100 Years

Over the past five years, sea level has risen at an average of 2 mm/year.

But as you can see, this is mainly due to the El Niño spike. If we look at the four years prior to that, the trend lowers to 1.4 mm/year.

Which is lower than the average rate (2 mm/year) for the last 100 years.

There is no ice sheet meltdown happening. Sea level rise is not accelerating. The whole story is completely in shambles.

What Is The Long Term Sea Level Trend?

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61 Responses to Sea Level Trends Nearly Constant For The Past 100 Years

  1. Brendon says:

    “There is no ice sheet meltdown happening.”

    This didn’t happen?

    Massive Arctic Ice Cap Is Shrinking, Study Shows; Rate Accelerating Since 1985

    … between 1961 and 1985, the ice cap grew in some years and shrank in others, resulting in an overall loss of mass. But that changed 1985 when scientists began to see a steady decline in ice volume and area each year.

    • “Ice loss in Greenland has had some climatologists speculating that global warming might have brought on a scary new regime of wildly heightened ice loss and an ever-faster rise in sea level. But glaciologists reported at the American Geophysical Union meeting that Greenland ice’s Armageddon has come to an end.”

      The only place the melted ice can go is into the oceans.

    • Amino says:


      You cherry picked a quote from the article. It also says this:

      “What we see during these warm summers is the extent of the melt is greater,” says Boon about the results of a five-year remote sensing study that ran between 2000 and 2004.

      The article didn’t mention anything about cold summers.

      But that’s what global warming is—it picks anything that favors alarmism and never mentions the rest of the story, because if it mentioned the rest of the story then there would be nothing to scare people with.

      • Brendon says:

        Cheery Pick? I highlighted the section of the opening paragraphs that summarised what the article was about. 50 years of data, some up some down, then from 1985 a continuing decline.

        Feel free to split it into warmer/colder summers/winters but the end result is an increase in melt.

        Steve thinks this doesn’t happen? Instead he wishes to try and divert attention to something else entirely (although he failed with that attempt too). Feel free to join his denial.

      • Amino says:

        The article does not cover ever year. It leaves out the cool years. And the study only covers 2000-2004.

        Cherry picked article. Cherry picked years. Cherry picked time frame for the study.

      • Brendon says:

        Read the article … “Close to 50 years of data show the Devon Island ice cap, one of the largest ice masses in the Canadian High Arctic, is thinning and shrinking.”

    • Go go go Stop STOP says:

      The anology that went immediately through my head: An investment advisor says he’ll double your money every year. After a year you’ve made nothing!

      You ask this “Madof” guy: “What happened?”

      Madof: “I didn’t get the first year right, but that doesn’t mean that I was wrong that I wouldn’t ‘double your money every year’!!!”

  2. Brendon says:

    HAHAHA Good one Steve. That article was in Jan 2009 .. and did Glacier melt come to an end?

    Greenland Glacier Calves Island Four Times the Size of Manhattan
    Researchers Witness Overnight Breakup, Retreat of Greenland Glacier

  3. Brendon says:

    How does that happen if, as you say, the summers are so cold!!

  4. Brendon says:

    btw: You might wish to label your second graph as “sea level change rate” to avoid more confusion. 😉

    • Brendon says:

      Scrap that, I see now he’s not trying to show the rate but instead openly cherry picking 4 years out of the data to try and get the result he wishes.

      • The last five years is “cherrypicking?”

        You are getting desperate.

      • Dikran Marsupial says:

        Yes, five years is cherry picking because it is of the same order as the characteristic timescale of ENSO. This has been discussed in the blogs at sufficient length that you ought to know that by now.

      • Dikran Marsupial says:

        BTW you could try calculating whether the trend is statistically significant or not (and not using it as the basis for any argument if it isn’t).

  5. TimC says:

    Brendon: a plot of “sea level change rate” would be a flat, *level*, line representing 2mm/century. Steve’s graph is correctly scaled. It is almost conclusive evidence that the situation since 1900 has been entirely normal; there has been no accelerated glacier melt and there is not the slightest indication of any so-called “tipping point”.

  6. R. de Haan says:

    Calving glacier ice, especially the big pieces is a very healthy sign.
    It means that the glaciers receive lot’s of snow.

    Obviously Brendan is a stout believer of all the AGW BS.

  7. Art Ford says:


    Downloaded the Colorado sea level data. Could you explain their dating convention for the layperson? For example, what is the actual date represented by “2010.6057”?

  8. Bob Tisdale says:

    Steve: You’re using the data that includes the seasonal cycle. Wouldn’t you be better off using the data with the seasonal cycle removed?
    That way you don’t have to start and stop your graphs on the same week.

  9. Some sea level acceleration was achieved by adjusting the data.

  10. TimC says:

    Alan: yes, the usual trick of unpublished/unjustified reductions in the earlier raw data. However we now seem to be getting into a litigation phase: the data and science may need to be justified before a court (the NZ High Court in the NIWA data case, the US Federal Courts for the Texas/EPA tailoring rule case etc) when normal discovery/disclosure rules will apply. That will be interesting!

  11. Scarlet Pumpernickel says:

    7 cities that are sinking LOL

  12. sentient says:

    Yes, not only is sea level rise very real and potentially quite destructive, but it’s actually worse than you think. It could happen in astonishingly little time!

    Catastrophic Climate Disruption is very, very real. Let no one dissuade you otherwise!

    Recent research suggests that there were at two warm pulses at the end of the last interglacial, the Eemian, with the last one likely responsible for a +6 meter rise in sea level, very likely achieved in less than a century, some suggest possibly in just a few decades. As this is dated to have occurred approximately 118 kyrs ago near the transition between MIS-5e and -5d, it can readily be assigned to natural “noise”.

    As six meters is roughly 20 feet, this adds some credo to Al Gore’s prognostication that humans might cause a 20-foot rise by 2100. Of course, this brings up the problem of how does one separate the anthropogenic “signal” from the natural sea level background “noise” if they are of the same amplitude?

    Perhaps more on-point is additional research targeting the end interglacials which continues to pry out more and more detailed pictures of a period or rapid climate instability that appears to have attended each of the “extreme interglacials”, or the ones that appear to have achieved similar sea level highstands as ours has, the Holocene.

    Now, with 5 of the last 6 interglacials each having lasted half of a precession cycle. The precession cycle ranges from 19-23 kyrs, and we are at the 23kyr end of that range today, so at 11,500 years old, the Holocene is more or less due for some rapid catastrophic climate disruption as we oscillate our way into the next ice age.

    So enjoy the interglacial, while it lasts!

    • TimC says:

      Err: I’m confused. Are we discussing sea-level rises (due to warming) or falls (glaciation/Milankovitch cycles) … or just hedging our bets?


  14. Alex the skeptic says:

    I live on an island which is geologically very stable. No earthquakes and no other type of geological activities, while tidal oscillations do not exceed 12 inches at most; nine inches is normal. I’ve been living on this island all my life, nearly six decades and swimming and boating is one of the few entertaining activities we have. I have found a number of what could be considered as fingerprints that mark the historical sea level variablity along the centuries, such as boat moorings, boat launches, steps cut in rock centuries ago, etc. They all point to one thing: Sea level changes during the past centuries are insignificant. I am not a scientist, but I do have a science degree and I can understand most of what is written in the climate debate. But one does not even need a science degree to measure the actual variability in sea levels. Just get down there, roll up your trousers and watch what has happened to the rocks during the last centuries.

    Now if our planet has to go into another ice-age mode due to the end of the current interglacial then let it come. No Al Gore, IPCC or superman will stop it. Not if we spend a century’s worth of our global GDP. Anthropogenic climate design will not work.

    • Dikran Marsupial says:

      I’m no geologist, but isn’t the fact that there are differences in the height of current and historical moorings (etc) an indication that your island is not “geologically very stable”? Roughly whereabouts in the world is your island?

  15. Alex the skeptic says:

    Dikran Marsupial:

    Did I mention “differences in the height of current and historical moorings (etc)…” ? No I did not. Please read again what I actually wrote and not what you think I wrote because there is a big difference. Let me help you: I said, quote, >They all point to one thing: Sea level changes during the past centuries are insignificant<

    As to where I live?

    Here we have the oldest free standing stone buildings ever dicovered. Come and visit. It will be such an enthralling experience, covering the history of the world, from the stone age to the historical handshake between Bush and Gorbachov that ended the cold war.

    • Dikran Marsupial says:

      Malta also apparently has some ancient buildings that are now underwater because Malta has been rising (it is on a boundary between continental plates), so perhaps it isn’t such a good place to look for rising sea levels.

      • Alex the skeptic says:

        Wrong: If we have buildings that are now underwater I would be the second person to know. Our sea floor has been scoured many a time for many reasons, from sunken Roman grain carriers to downed world war two aircraft and sunken battleships, mostly Italian, British and German. A lot has been found but as yet no buildings, I’m sorry to say. I gave you a link showing our prehistoric stone buildings to make you realise how geologically stable our tiny rock is. May I repeat: I could never find any indication of a significant, measurable sea level flactuation in this part of the world.

  16. Dikran Marsupial says:

    Malta is on a convergent plate boundary, thus it isn’t geologically stable, the most of the Eastern mediterranian is tectonically active.

    • Find a beach on the Pacific Ocean that isn’t tectonically active. Good luck!

      • Dikran Marsupial says:

        Not too difficult, the Midway Islands are well away from any plate boundary and the mantle plume that generated them moved away millions of years ago (long enough for isostatic adjustment to be insignificant). I would have thought they would be as tectonically inactive as you will get.

        It is pretty much only the Pacific rim that is really tectonically active.

    • Alex the skeptic says:

      @Dikran Marsupial: Read some geography. Malta is right in the center of the Med sea and not in the east Med. We hav’nt had an earthquake since 1693, and that was due to the eruption of mount Etna in sicily. Sicily is split between two tectonic plates with southern Sicily and Malta being on the same plate. The fault line here practically lies west to east, across the Med from Gibraltar through Greece and Turkey. But I would not like to turn this into a plate tectonics thread. Let’s keep on track, that is, ocean levels. Fact is that what I have been observing for the past half a decade on this little rock 21 miles x 17 miles and its sister island of Gozo (the island of Calypso in Greek mythology) is that one cannot find any real traces of any noticeable sea level rise or decline across the centuries. We have historical records that persist from the Roman period…………when humanity was prospering due to the Roman Warm Period, the warmer earth causing an increase in food production that helped the Roman empire to prosper, only to fall when the next global cooling took hold, causing famines, wars, empire downfalls, what today is referred to the DARK AGES.

      The following link shows a description and photos of Malta’s Grand Harbour, a natural harbour that has been in use for the past two millenia at least.

      These 20 centuries of history can be traced on the shoreline, fortifications and other man made structures along this great harbour (and along most of Malta’s shoreline). There are no indications of any significant changes in sea levels, at least not in this part of the world. Come and see for yourself.

      Locally we also have the catastrophic Climate Change discussion including ocean levels.
      and includes, quote >
      “Our ground water sources will be long gone before climate change happens. If nothing is done, we face the prospects of higher water tariffs every year because the country would depend solely on expensive and energy-guzzling reverse osmosis plants to satisfy the demand,” Mr Cremona said.

      The engineer warned this was not only an environmental problem but one of national strategic importance.

      “Unfortunately, there is no sense of urgency in the country to address the issue,” he insisted.

      The symposium also heard that the sea level around the Maltese islands was dropping rather than rising.

      Marine biologist Alan Deidun said data analysed by the University’s Physical Oceanography Unit, which had a sea level monitoring station at Portomaso, showed how sea levels around Malta, contrary to popular belief, had “fallen slightly”. < unquote.

  17. Alex the skeptic says:

    @Dikran Marsupial: And how about the salt pans built during the Roman times and which are still in good shape and in use? Their present level wrt to the sea level is just perfect for pumping sea water during spring, let it dry during the summer months, and harvesting the salt crystals during Autumn. No sea level changes here. If this does not convince you……………

    then maybe this will:

  18. tymcd says:

    The earth has been warming and cool for billions of years, yet somehow we are responsible for the changes that have occurred the last couple of hundred years. What an ego.

    • ChrisD says:

      It’s not ego, it’s science. There’s no conflict between natural change and anthropogenic change; they can both exist.

      The problem with “it’s all natural” is that you have to come up with a natural explanation for the warming we’ve seen for the last 35 years or so. None of the natural causes of climate change that we know about can do that. By all accounts we should have been cooling, not warming.

      • TimC says:

        If you consider this thread for a moment, if the data used in Steve’s graph is correct it is almost conclusive evidence that the situation since 1900 has been entirely normal; there has been no change in the rate of ice sheet/glacier melt, no warming-driven thermal expansion of the oceans and there is not the slightest indication of any so-called “tipping point”.

        If there had been any anthropogenic warming it would show up in this data. The simple explanation is probably that it’s all an artifice of the system of measurement.

        And the total mass of all of us 6.9 billion humans on the planet is about 1E-9 of the mass of the atmosphere. Yes, it is somewhat egotistical to think we can have much impact.

      • Alex the skeptic says:

        ChrisD says:
        October 13, 2010 at 1:55 am
        The problem with “it’s all natural” is that you have to come up with a natural explanation for the warming we’ve seen for the last 35 years or so. None of the natural causes of climate change that we know about can do that. By all accounts we should have been cooling, not warming.

        ChrisD: Try this chart and see what has been happening to our climate WITHOUT ANY anthropogenic forcings whatsover during the past 5000 years. If the planet can warm up and down naturally for 4500 years, why should’nt it warm or cool for 30 years? 30 years is nothing. It’s just a tiny weeny bit of a blip compared to this: Hit the link and scroll down to the bottom. May I recommend that you sit down beofre looking at the chart.

      • ChrisD says:

        if the data used in Steve’s graph is correct it is almost conclusive evidence that the situation since 1900 has been entirely normal….

        This doesn’t address my point at all.

        Yes, it is somewhat egotistical to think we can have much impact.

        This does, but it’s just an assertion. Things aren’t so just because you say they’re so. Comparing the mass of humans to the mass of the atmosphere is, well, I don’t know what it is. It sure doesn’t illustrate anything.

        No one that I know of disputes that CO2 is a greenhouse gas. We’re responsible for a ~40% increase in that greenhouse gas. What’s “egotistical” about saying that this can cause some warming to occur?

    • ChrisD says:

      30 years is plenty long enough to show a change in the global climate because it’s sufficient data for weather noise to average out. It’s straight statistics; no grant-hungry climate scientists are required. So the “It’s not long enough” argument goes out the window.

      So, if the climate is changing, what is the cause? Is it natural or anthropogenic? You say it’s natural. Fine. But climate change isn’t voodoo. It doesn’t happen for no reason. If it’s natural, there’s a natural reason why it changed–insolation changed, or Earth’s orbit or tilt changed, or there were a lot of big volcanoes, or whatever. If you don’t specify the reason, it’s just handwaving. It’s the doctor saying, “My diagnosis is that you’re sick. Pay the receptionist on the way out.”

      So, what’s the natural reason for the warming trend of the last 30 years or so?

      • TimC says:

        What “warming trend” is that exactly? The whole point of this thread is that if there had been any additional AGW-driven warming it would show as an acceleration in sea level rise (adjusting for natural El Nino/La Nina events), due to thermal expansion of the ocean. The data shows no such acceleration from 1900 to date – just normal, steady, recovery from LIA. There is additional “warming trend” apparent yet.

      • ChrisD says:

        What “warming trend” is that exactly?

        Well, the warming trend that all four of the major global datasets show.

        As for “normal, steady recovery from LIA”, natural forcings alone correlate nicely with temp trends up to about 1970; at that point the temps begin to rise when they should be cooling. The only way to explain this is to combine natural and anthropogenic forcings (see, e.g.,

        “Recovery from LIA” is still handwaving; it’s just a little more subtle than “It’s natural.” You still have to come up with specific natural causes for the warming we’ve observed over the last 30-40 years.

      • TimC says:

        My point is that the sea level data presented in this thread immediately casts doubt on the accuracy of the “major global datasets” you refer to, particularly whether there is any real “warming trend” at all.
        To spell it out clearly, other than natural ENSO and PDO variability, I am suggesting that there is no warming trend. Given that, asking me to assume a warning trend and then suggest a mechanism that could have caused it is nonsensical, and a probable troll. I think we are done here.

      • ChrisD says:

        Using SLR as a temperature proxy and then using that proxy to insist that all four datasets constructed from more direct temperature measurements are wrong is, well, it’s a pretty dang strange thing to do.

        Sorry, but that’s a fact. It’s a very, very strange thing to do.

      • There are only two important variables which affect sea level. Temperature and glacial mass balance.

        If sea level rise is not accelerating, then the global warming story doesn’t fly. Period. End of story.

        You can’t change the rules of science to support a religion.

  19. Martin C says:

    Chris D said, ” . . natural forcings alone correlate nicely with temp trends up to about 1970;at that point the temps begin to rise when they should be cooling . .”

    What information have that says the temps should have cooled?

    The PDO, AMO, and solar activity correlates very well with the temperature increase (see this site:

    There is further discussion about correlation and smoothing of the data to get a better correlation, but the idea still is valid.

    Now there may be others things involved too. CO2 may play a small part (very small from the information I have read).

    Getting back to seal level rise – the fairly constant rise in the last 100 years I would expect to be from the combination of in ice melt from glaciers, icecaps, and temp increase (as Steve noted); though I attribution to each I don’t know. But the thing to note is it is not accelerating.

    So, as Steve has pointed out before, if according to Hansen, the past 12 months was that hottest ever (or even second), why has the sea level dropped the past year?

  20. Pingback: Global Warming Hoax Weekly Round-Up, Oct. 14th 2010 « The Daily Bayonet

  21. cptwayne says:

    Look, the real problem is false assumptions or ignored other effects. Seal level rise is not significant or unusual at this time. Same with CO2 and the greenhouse effect. The radiative effect of CO2 for warming is about 8%, but the increased convective cooling effects of heat transfer increases the lapse rate to offset this warming. The net result is cooling, not warming for increased atmospheric CO2.

  22. cptwayne says:

    The real problem is false assumptions or ignored other effects. Sea level rise is not significant or unusual at this time. Same with CO2 and the greenhouse effect. The radiative effect of CO2 for warming is about 8%, but the increase in convective cooling effects of heat transfer (rising hot air followed by cooling) more than offsets this warming in the lower troposphere.

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