Global Sea-level Rise: Faster than Ever?

by Charles Clough

recent_sea_level_rise

Sea level rise to 2005. Image from WUWT archive for purpose of illustration. Not part of the original essay.

In yet another instance of the media jumping on the climate alarmist bandwagon, The New York Times this past February boldly headlined “Seas Are Rising at Fastest Rate in Last 28 centuries.” The article went on to proclaim “the worsening of tidal flooding in coastal communities is largely a consequence of greenhouse gases from human activity, and the problem will grow far worse in coming decades, scientists reported Monday.”

“Worsening tidal flooding”—“grow far worse”—scary words for coastal inhabitants, but do they help the reader understand what the two reports (here and here) actually said? More importantly, do they help the reader evaluate what was reported? Or does the NYT wording continue the intellectually shallow but emotionally potent sea-level terror theme of Al Gore’s movie, An Inconvenient Truth?

The two reports published in the Proceedings of the National Academy of Science (PNAS) made several claims. During pre-industrial history (prior to 1860), global sea level rose at an average rate of 0.1 to 0.3 mm/yr. From 1860 to 1900 it rose at an average rate of 0.4 mm/yr, and from 1900 to the present it has been rising at 1.4 mm/yr. The studies project for various hypothetical CO2 emission-increase scenarios during this 21st century a total rise in global sea level between 1 ft and 2.5 ft.

First, observe that “tidal flooding” is not the same as the spectacular “storm-surge” that accompanies severe coastal storms like Sandy or the fictionalized surge in the 2004 apocalyptic sci-fi film The Day After Tomorrow. Such surges can easily exceed the reports’ estimated increase in tidal flooding by ten times or more. You probably wouldn’t know that from media stories like the NYT piece. Mitigation of known storm surge damage could protect coastal communities from the worst guesses of sea-level rise for the rest of this century!

Second, forecasting sea-level rise involves even more guesswork than forecasting global warming. Actual sea-level direct measurement data exist only for a century and a half and only for a few regions of the earth. Even in the world’s best documented region, the eastern North Sea and Baltic region, tide-gage records of sea-level measurement are less than 200 years old. Estimates of sea-level changes over 28 centuries necessarily rely upon layers of interpretation of various proxies such as evidence of shoreline changes. Extensive modeling, therefore, is required as the two PNAS papers demonstrate. Each model element to some degree has to involve guesswork. Resulting estimates of sea-level rise rates vary from 1.15 mm/yr to about 3 mm/yr—a considerable variation for any long-term projections.

Third, tide gages and proxies give relative sea-level, not absolute sea-level. They show sea-level relative to the land level. Absolute sea-level measurements from satellite only began in the early 90s—too recent to establish significant trends. To obtain absolute sea-level measurements from relative measurements or proxies, scientists have to correct for many variables—vertical changes in both land and ocean basin levels, ocean salinity changes, overland glacial decreases and increases, on-shore-off-shore prolonged winds, and gravitational interactions between the earth and lunar orbits. Would readers of media headline articles know that?

Finally, there is the problem of learning how long the oceans take to reach equilibrium once there is a change in global temperature. Temperatures have been generally rising and sea-levels with them ever since the end of the ice age thousands of years ago. But there have been numerous up-and-down oscillations in this general trend, none of which is well understood. Are we in one or more of these oscillations now?

Given these caveats in the reasoning behind the claim that “seas are rising at the fastest rate in the last 28 centuries,” it comes as no surprise that renowned experts in the field like Dr. Nils-Axel Mörner of Sweden don’t take these reports seriously. Mörner challenges one of the PNAS papers, pointing out several of its conflicts with actual observations: nowhere do global tide gauges show valid increases in the rate of sea-level rise, and new satellite altimetry of absolute sea-level when carefully calibrated shows a mean rise of 0.5 mm/yr, not the modeled 1.4 mm/yr.

Since atmospheric CO2 emission levels do not correlate with such changes prior to the industrial age, the upward trend in temperature and sea level will continue regardless of the political campaign to impose economy-destroying carbon asceticism on the world’s population. Readers of such articles ought to heed the advice of Harvard oceanographer Roger Revelle (whom Al Gore claimed taught him fear of global warming’s planetary effects). Revelle’s last published article (co-authored with S. Fred Singer and Chauncey Starr) before his death was entitled “What to Do about Global Warming: Look before You Leap” (Cosmos 1 (1991): 28–33).


Atmospheric physicist Charles Clough, Bel Air, MD, is retired chief of the U.S. Army Atmospheric Effects Team at the Aberdeen Proving Ground, MD; retired Lt. Col., U.S. Air Force Reserve Weather Officer; President of Biblical Framework Ministries; adjunct Professor at Chafer Theological Seminary, Albuquerque, NM; and a Fellow of the Cornwall Alliance for the Stewardship of Creation.

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118 thoughts on “Global Sea-level Rise: Faster than Ever?

  1. “…and new satellite altimetry of absolute sea-level when carefully calibrated shows a mean rise of 0.5 mm/yr, not the modeled 1.4 mm/yr.”

    Dr. Clough,

    Thanks for this fine post. I think many here would appreciate a link to your reference for the above.

    • Ditto.

      That is quite a surprising claim, which is not much use as a bland assertion. I would certainly be interested in the source of this figure.

    • Well clearly the assertion that sea level is rising at the highest rate in the last 28 centuries, is quite bogus.

      You can clearly see just as recently as 1990, a much higher rise rate than now, or in 1915 or around 1960; much greater rates of se level rise than now.

      What total BS.

      G

    • I am also interested in knowing if the tidal gauges have always been in the exact same location, and in truth, how orbital changes of the satellites are calculated in order to measure the “absolute sea level rise.” Can I assume the satellite orbital path is somehow tied to the exact center of the Earth, thus able to actually distinguish changes in layers below it?

      I have heard there is an area near Malaysia, Indonesia, somewhere in that region, showing a strong unthrusting of the ocean floor. How, exactly do you factor out the displacement of water that such a thing would do? Would that not show up as a general rise in sea level? How many other areas of the deep seas are also showing this type of change? Are they accounted for? so many ways to raise the level of the sea relative to the land, that there really can’t be a realistic reason to proclaim sea level rise is temperature driven, much less understood.

  2. all this crap science is getting in the way of me enjoying the weather. make these fawkin’ arse holes prove
    their science. if they can’t, run them out of the industry. Hell, burn’em at the stake, off with their heads.
    put a burning bag of dog shiit on their porch and lay a fire to it. I say ‘prick’em’ real good. make fun of’em.
    show’em off to be the retards that they are…

  3. During pre-industrial history (prior to 1860), global sea level rose at an average rate of 0.1 to 0.3 mm/yr.

    This is often claimed, but ignores the ups and downs in between.

    HH Lamb, along with sea level experts of his time, are clear that these changes were significant:

    https://notalotofpeopleknowthat.wordpress.com/2016/05/13/sea-levels-in-the-holocene/

    We know that glaciers advanced strongly during the LIA, to their greatest extent since the ice age in many if not all places. We also know that the LIA was the coldest period in many areas since that last ice age.

    And we wonder why sea levels have been rising since the mid 19thC?

    I have also yet to see any evidence from tide gauges that the recent rate of rise is any higher than around the mid 19thC.

  4. Oooh! We are all going to drown! .5mm a year sea level rise–oh damn, that is less than two inches a century. Another disaster that just isn’t there;-)

  5. This nonsense was also in the Washington Post

    A group of scientists says it has now reconstructed the history of the planet’s sea levels arcing back over some 3,000 years — leading it to conclude that the rate of increase experienced in the 20th century was “extremely likely” to have been faster than during nearly the entire period.

    https://www.washingtonpost.com/news/energy-environment/wp/2016/02/22/seas-are-now-rising-faster-than-they-have-in-2800-years-scientists-say/

    This is the source of the nonsense…

    Temperature-driven global sea-level variability in the Common Era

    Significance

    We present the first, to our knowledge, estimate of global sea-level (GSL) change over the last ∼3,000 years that is based upon statistical synthesis of a global database of regional sea-level reconstructions. GSL varied by ∼±8 cm over the pre-Industrial Common Era, with a notable decline over 1000–1400 CE coinciding with ∼0.2 °C of global cooling. The 20th century rise was extremely likely faster than during any of the 27 previous centuries. Semiempirical modeling indicates that, without global warming, GSL in the 20th century very likely would have risen by between −3 cm and +7 cm, rather than the ∼14 cm observed. Semiempirical 21st century projections largely reconcile differences between Intergovernmental Panel on Climate Change projections and semiempirical models.

    […]

    Since, I know that sea level isn’t rising any faster now than it was in the early 20th century and I know that tide gauge records sufficient for global reconstructions only date back to the 1700’s… I wondered where they obtained sufficiently high-resolution proxy data to make such a fantastic claim. A brief perusal of the paper leads to one inescapable conclusion: They didn’t… They just ginned up a hockey stick…

    The increasing availability and geographical coverage of continuous, high-resolution Common Era RSL reconstructions provides a new opportunity to formally estimate GSL change over the last ∼3,000 years. To do so, we compiled a global database of RSL reconstructions from 24 localities (Dataset S1, a and Fig. S1A), many with decimeter-scale vertical resolution and subcentennial temporal resolution. We augment these geological records with 66 tide-gauge records, the oldest of which (11) begins in 1700 CE (Dataset S1, b and Fig. S1B), as well as a recent tide-gauge–based estimate of global mean sea-level change since 1880 CE (12).

    […]

    The spatial coverage of the combined proxy and long-term tide-gauge dataset is incomplete. The available data are sufficient to reduce the posterior variance in the mean 0–1700 CE rate by >10%>10% relative to the prior variance along coastlines in much of the North Atlantic and the Gulf of Mexico, and parts of the Mediterranean, the South Atlantic, the South Pacific, and Australasia (Fig. 2A). High-resolution proxy records are notably lacking from Asia, most of South America, and most of Africa. Nevertheless, despite the incomplete coverage and regional variability…

    […]

    The database is not a complete compilation of all sea-level index points from the last ∼3,000 years. Instead, we include only those reconstructions that we qualitatively assessed as having sufficient vertical and temporal resolution and density of data points to allow identification of nonlinear variations, should they exist. This assessment was primarily based on the number of independent age estimates in each record. Where necessary and possible, we also included lower-resolution reconstructions to ensure that long-term linear trends were accurately captured if the detailed reconstruction was of limited duration. For example, the detailed reconstruction from the Isle of Wight (69) spans only the last 300 y, and we therefore included a nearby record that described regional RSL trends in southwest England over the last 2,000 y (51).

    […]
    http://m.pnas.org/content/early/2016/02/17/1517056113.full

    They just spliced high-resolution tide gauge records onto low-resolution geologic proxy data.

    Koop01

    This is their sea level reconstruction. It is clearly a hockey stick.

     

    Koop02

    For a little perspective, I added their error bars and a 12-inch ruler.

     

    Koop03

    They get away with saying this, “a significant GSL acceleration began in the 19th century and yielded a 20th century rise that is extremely likely (probability P≥0.95P) faster than during any of the previous 27 centuries,” because of this.

     

    Koop04

    Even if their reconstruction is valid, all of the “rapid” sea level rise of the 20th century disappears if the reconstruction is carried back to the Holocene transgression and highstand…

    • Semiempirical = Semifantastic

      Never saw that word before, but it’s meaning is clear

    • Wow, spice fest, how very Mannian, in other words the reconstruction is not a reconstruction, it is several, all differing in proxy and resolution with massive missing pieces of the puzzle, what a logic fail of a paper

    • David, I don’t think they realize that their own graphs….show most of the rise could be called recovery

      • doesn’t this confirm Latitude’s comment (above yours) above ‘recovery’: look at the last 10-13 centuries and net rise is practically zero.

      • The 1st through 19th centuries weren’t part of the early 20th century. In the future try to learn to read.

      • Seth, that bar graph is perfectly consistent with the fact that there’s been no acceleration in the rate of sea-level rise since the first quarter of the 20th century.

    • “many with decimeter-scale vertical resolution …”
      Since the estimated SLR is less than a decimeter, how is a proxy with decimeter scale vertical resolution going to give you ANY useful information? Pure BS!

    • Didn’t someone write in WUWT that the Earth is a low pass filter and that low pass filters reduce variability, so that ALL proxy reconstructions must systematically have less variation than was really there?

  6. If anybody really knew the global seal level over the last 3 millennia and could distinguish convincingly between steric and eustatic changes, we’d have evidence-based scientific perspective As it is, we only have wildly tendentious speculation.

  7. Why did you stop the sea level chart at 2005, leaving off the last ten years of data?

    [that’s not part of the original essay, since the author didn’t provide an image, and one is required for the format we use, one was used from our files – mod]

  8. Science or pseudo-science aside, it is interesting to me that coastal real estate values are higher than comparable inland values. Seems like those that can afford homes on the coast are rejecting the hypothesis that the reported sea levels changes represent a danger to their investment. Curious, that these same folks disproportionally “believe” (as in a religion) that CO2 moving from 3 to 4 parts per 10,000 represents the single biggest threat to our planet. I guess that followers of any religion reject, by their actions, those assertions that they intrinsically know to be false. Perhaps there is wisdom in crowds after all.

    • “Seems like those that can afford homes on the coast are rejecting the hypothesis that the reported sea levels changes represent a danger to their investment.”

      Indeed. It’s quite amazing what looking out of your window can tell you.

      • Except that Hansen looked out of the window of his office and saw the ocean covering the highway.
        Just as Mary saw Gabriel and Moses saw the burning bush.
        You and I will never see these things.
        We are mere mortals.

    • PI&e wrote: it is interesting to me that coastal real estate values are higher than comparable inland values.

      A false economy in part, in the case of the USA. The National Flood Insurance Program has gone $25 billion in debt to prop up house prices in flood prone areas.

      If the owner were exposed to the correct actuarial rates for flood insurance, the story would track reality better.

      But there are certainly some suburbs where sea level rise is dropping prices:

      http://www.theherald.com.au/story/1541683/fears-sea-level-policy-may-slash-1bn-off-property-values/

      • “Flood prone areas” refers to natural disaters, not to rising sea levels. And per that silly link, anyone who can’t sell their lakeside homes can deed them to me; I’ll take their problem off their hands.

        This “dangerous man-made global warming” scare has gotten so out of hand that stories like that are actually taken seriously by some folks.

        They sound just like Chicken Little, running around in circles, clucking that the sky is falling.

        It isn’t. With Chicken Little it was just a tiny acorn — which is more than the global warming alarmists have to show for their own false alarm.

      • It really is sad when pathetic trolls can’t be bothered to read the articles they tout as proof.

        The first line of the article says it all:

        “RESIDENTS fear Lake Macquarie City Council’s controversial actions on the risks of sea level ”

        It is the actions of the City Council that are causing problems, not sea level rise.

  9. Here is a graphic of the data. Obviously, there was data selection going on here where they selected using sea level reconstructions from areas which is sinking as a result of Glacial Rebound from the last ice age.

    I always urge people to look at the base data from these studies. The authors pretend that they are completely above board but obviously someone was playing around with sea level reconstruction data and said “Heh, we can be heros if we just use these datapoints and try to pretend everything is scientific and act “all objective and everything”.

    Throw this crap out.

    Data sourced at the supplemental.

    http://www.pnas.org/content/suppl/2016/02/17/1517056113.DCSupplemental

  10. The lead-in of this article, on the first impression appears to legitimize its premise. I favor hard hitting, skepticism that characterizes the article and authors as utterly full of shit–because they ARE!

  11. Am I correct in observing that some fools are suggesting that the 20th century rise is necessarily man-made i.e. CO2 driven? Even though according to the only record extending over that period, i.e. tide gauges, the rise from 1900 to 1958 is almost exactly half the rise from 1958 to 2016.
    How does that fit with the theory of runaway greenhouse warming caused by rising CO2 emissions?
    Or was the first half of the rise natural and then the identical second half exclusively man-made.

    FFS – It’s a linear rate and completely unspectacular in historical terms.
    Their analysis seems naive – the past always looks smoother.
    We can’t even agree about the specifics of sea level rise today, when we have reliable gauges and over one hundred years of records at numerous locations.
    (Inasmuch as the consensus estimate has changed from 1mm/yr to 3.2mm/yr in just the last few decades.)
    What chance have we of obtaining measure of precise levels and rates several hundred years before any attempt to measure or document the sea level?

    The IPCC was right about this topic in the first place. Since then they have got more wrong. To quote:

    “Past changes in sea level
    From recent analyses, our conclusions are as follows:

    Since the Last Glacial Maximum about 20,000 years ago, sea level has risen by over 120 m at locations far from present and former ice sheets, as a result of loss of mass from these ice sheets. There was a rapid rise between 15,000 and 6,000 years ago at an average rate of 10 mm/yr.
    Based on geological data, global average sea level may have risen at an average rate of about 0.5 mm/yr over the last 6,000 years and at an average rate of 0.1 to 0.2 mm/yr over the last 3,000 years.
    Vertical land movements are still occurring today as a result of these large transfers of mass from the ice sheets to the ocean.
    During the last 6,000 years, global average sea level variations on time-scales of a few hundred years and longer are likely to have been less than 0.3 to 0.5 m.
    Based on tide gauge data, the rate of global average sea level rise during the 20th century is in the range 1.0 to 2.0 mm/yr, with a central value of 1.5 mm/yr (as with other ranges of uncertainty, it is not implied that the central value is the best estimate).
    Based on the few very long tide gauge records, the average rate of sea level rise has been larger during the 20th century than the 19th century.
    No significant acceleration in the rate of sea level rise during the 20th century has been detected.
    There is decadal variability in extreme sea levels but no evidence of widespread increases in extremes other than that associated with a change in the mean.”

    https://www.ipcc.ch/ipccreports/tar/wg1/409.htm

    • Am I correct in observing that some fools are suggesting that the 20th century rise is necessarily man-made i.e. CO2 driven?

      That doesn’t need to be suggested. The components of sea level rise have been under study.

      FFS – It’s a linear rate and completely unspectacular in historical terms

      About five times faster now that at the start of last century.

      No significant acceleration in the rate of sea level rise during the 20th century has been detected.

      This paper finds the acceleration significant:

      http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.178.7972&rep=rep1&type=pdf

      As does this one:

      http://link.springer.com/article/10.1007/s10712-011-9119-1

      The IPCC AR5 (The one two more recent than the one you quote) says “[I]t is likely that the rate of sea level rise increased from the 19th century to the 20th century.”

      So I think it matters as to what confidence you call “significant”.

      • Satellite SL measurements are not nearly as accurate as the average of all tide gauges. I keep explaining why, but some folks just don’t get it.

      • Amazing that the temperature of the ocean can change so much in just a decade here and there to cause all that melting. Guess there’s not much heat capacity in a gazillion tons of seawater. And the ocean seemed to know more CO2 would be burned in the future and adjusted ahead of time.

      • I read somewhere that satellite measurements were free of all the adjustments that were required for land based measurements and were therefore superior. I think the context was temperatures, but the same issues apply here. Land based measurements tide measuements must be adjusted for relative land movements.

      • seaice says:

        I think the context was temperatures, but the same issues apply here.

        Wrong as usual. Satellite temperature measurements are accurate. But averaged tide gauges are far better for sea level measurements.

      • Oh look…when you change to another methodology the rate suddenly changes.
        AND…that graph has been constructed to hide what we would see, if they had provided a continuation of the same tide gauge methodology ALONG SIDE the satellite data.
        Have you never asked yourself why they don’t want us to see the two methodologies side by side.
        How gullible would a person have to be to fall for this stunt?
        If your overweight friend told you that he had instantaneous lost 20kg since he bought some cheap second hand scales from a yard sale. And on top of that – he refuses to demonstrate the use of the new scales and the old scales, side by side. Would you believe that his claim of spectacular and sudden weight loss was real. Or would you suspect a problem with instrumentation or methodology.
        Look – it’s a STEP change in rate. AND they are hiding the comparison.
        Some people here may be excessively skeptical. I accept that.
        But – total gullibility is nothing to be proud of.
        Ask questions now and again, FFS. You might learn something about the nasty real world where people lie and cheat whilst pretending to be the world’s top climate boffins.

      • James Hansen is up to his usual tricks doctoring data and pasting two different data sets into the same graph to deceive people. That graph shows tide gauge data until 1993 then satellite data from 1993 onward.

        Was there a sudden jump from 1.4 mm/yr to 3.3 mm/yr in 1993? No.

        Did the tide gauge record end in 1993? No.

        Why wasn’t the tide gauge data after 1993 included in the graph? Because it shows no acceleration in sea level rise, but splicing two different records falsely shows a (very sudden) acceleration in sea level rise, which fits the scary story Hansen likes to tell.

        Satellite telemetry instruments and tide gauges produce different results. There are reasons for the difference but Hansen doesn’t cover that; let’s not confuse people with uncertainties.

        NASA’s “Vital Signs” website has a graph that shows the same satellite data (1993 to present) and the tide gauge data from 1870 to 2000.

        http://climate.nasa.gov/vital-signs/sea-level/

        There is a 7 year overlap. There is no acceleration from 1993 to 2000 in either record, which illustrates the fact that the different rates are a result of measurement differences, not what’s happening to sea levels.

        Though NASA does a better job than Hansen the Deceiver, they can’t resist their own deception. Only the top graph (satellite) enumerates the Rate of Change (3.42 mm per year). The bottom graph doesn’t have the annual rate listed and the axes for the bottom graph (tide gauge) are purposely chosen to make the slope of the graph appear identical to the upper one. The rate is in fact 1.54 mm per year, less than half what the upper graph shows, but neither graph shows any acceleration in sea level rise, and they don’t show a rapid acceleration between 1993 and 2000 where they overlap. So, in fact, NASA debunks Hansen’s graph. There is no acceleration in sea level rise.

      • You’ve grafted different datasets onto a single plot. Where might I have seen that before?

      • Seth, the acceleration identified in the two papers you cited predated the vast majority of the anthropogenic contribution to GHG levels. There’s been no detectable, sustained acceleration in the rate of coastal sea-level rise since the 1920s, despite a 30% increase in CO2, and a 75% increase in CH4. Every high-quality, long-term measurement record of coastal sea-level shows that.

        That means anthropogenic GHGs have caused no detectable increase in the rate of sea-level rise. In fact, most coastal sea-level measurement records show no acceleration since sometime in the 1800s. Here are a few representative coastal sea-level measurement records:

        Lauren R got it exactly right: “James Hansen is up to his usual tricks doctoring data and pasting two different data sets into the same graph to deceive people. That graph shows tide gauge data until 1993 then satellite data from 1993 onward. / Was there a sudden jump from 1.4 mm/yr to 3.3 mm/yr in 1993? No. / Did the tide gauge record end in 1993? No. / Why wasn’t the tide gauge data after 1993 included in the graph? Because it shows no acceleration in sea level rise, but splicing two different records falsely shows a (very sudden) acceleration in sea level rise, which fits the scary story Hansen likes to tell.”

        Conflating reliable, high-quality coastal sea-level measurements (from tide gauges) with dubious mid-ocean measurements (from satellite altimetry) is scientific malpractice. It creates the illusion of acceleration, when none is actually present. Tony Heller memorably called it the “IPCC Sea Level Nature Trick.”

        Oh, and by the way, Seth, your Hansen graph is out-of-date. His newer version shows a satellite rate from a more recent analysis of the satellite data, which reduces the satellite altimetry rate from 3.3 mm/yr to 2.6 mm/yr.

        At that rate of decline, we can project that in less than a decade the reported satellite altimetry rate should be down to about the same as the average coastal (tide gauge) rate (6″/century = 1½ mm/yr):

  12. Yes splice proxy data with instrument data for a hockey stick of your choosing. It must have came from Hockey Stick U.

  13. Anyone ever noticed that random crap (1) + random crap (2) … + random crap (n) tends to produce a more flat hockey stick shaft as n is increased? Just throw in more proxies and the past can be ironed smooth. The more unreliable and random – the better!!
    Eventually, the entire history of the earth’s climate could potentially be disappeared.
    1765 could be declared year zero.
    “One Sunday in 1765, Watt was struck by the idea that was to spark the Industrial Revolution.”
    And then climate change began.

  14. If the sea level was really rising over many years, wouldn’t we expect the high water mark on large objects in the sea be getting higher up? It’s not doing so. Have a look at the wall at the foot of the Statue Of Liberty, or the Great Wall of China where it reaches the sea. Have a look at roads by the seaside. Are they more flooded now in places where the land is not falling? Not where I live.

    • re:Have a look at the wall at the foot of the Statue Of Liberty

      You don’t have to trust your memory. There’s a tide gauge just across the Hudson from there with over 150 years of data.

      re:It’s not doing so

      I enjoy your optimism. Alas you’re probably mistaken.

      • Cherry-picking one spot on the planet ignores land uplifting and subsidence (but it does use tide gauges, which taken together are more accurate than satellite SL measurements).

        Here is a picture of a Mean Sea Level mark carved into stone in Tasmania in 1841. The MSL has not changed since then:

      • You are right. It is not zero sea level rise. Most people would not claim it is zero (yes, I know jaymam did). From 1890, it is about 13-14 inches over ~125 years. Notice how linear it is. That’s about 1/10 of an inch per year or 2.8 mm/year. Not sure if that has been corrected for subsidence or not. But clearly some places have seen 2.8 mm per year for over a hundred years with no acceleration. As with many things in real science, it needs to be studied much longer before we will actually know what is going on. Luckily we had a pause for a decade or two so we can study it more without panicking like fools. In New Orleans, thanks to dams/levees built by progressives over the last century, 1/2 to 2/3 of the “rise” is actually due to subsidence.

  15. It’s always useful to look at the data and graphs from authoritative sources. From NASA’s Global Climate Change “Vital Signs” website:

    http://climate.nasa.gov/vital-signs/sea-level/

    The upper graph of sea level covers 1993 to the present, measured by satellites. The rate of change is prominently displayed as 3.42 mm per year.

    The lower graph of sea level covers 1870 to 2000, measured by tide gauges. The rate of change is (purposely) not displayed and the graph axes are chosen so the trend line looks identical to the upper graph. If you do some quick math you’ll discover the trend from tide gauges (200 mm ÷ 130 years) is about 1.54 mm per year.

    The trend measured by tide gauges is less than HALF of the trend measured by satellites. No wonder they didn’t display it. Why they differ so drastically is a great question. Which is more accurate? Tide gauges are affected by land subsidence and uplift which should (but probably isn’t) factored out at each location. Satellites are affected by orbital decay and their instruments aren’t accurate enough to determine sea levels with millimeter precision from hundreds and thousands of miles away.

    Setting that discussion aside, the more important points are:

    1. Neither graph shows any acceleration of sea level rise, just an upward linear trend. So much for all the claims of accelerating sea level rise.

    2. The actual measured sea level rise projected out to 2100 is much lower (between 0.13 meters / 1.15 inches to 0.29 m / 11.45 in) than even the lowest rate, RCP2.6, projected from IPCC AR5 (2013) which is 0.26 m / 10.23 in to 0.55 m / 21.65 in).

    FYI, RCP2.6 is the fairy tale scenario where everyone magically cooperates globally to keep the temperature increase down below 1.8° C.

    • To summarise. the data on the NASA site says sea level rise from 1993 to present was 3.42 mm/yr (from satellite). The sea level rise from 1870 to 2000 was 1.54mm/yr. (from tide guages). You then say there is no evidence for accelerating sea level rise? One explanation is that sea level rise has accelerated, so that the average rate from 1993 to 2016 is much higher than the rate from 1870 to 2000.

      • Do you specialize in using two different rulers of unknown accuracy over two periods of grossly different length and then equating them?

      • Yes, by all means, let’s compare apples and oranges and then jump to conclusions after only a decade or so of “apples”.

      • The graphs on NASA’s “Vital Signs” website overlap for 7 years between 1993 and 2000. Did you see any acceleration in sea level rise during that time? Neither did I. Two different kinds of instruments affected by different parameters will yield different measurements, which is what the two graphs show. Bottom line: no acceleration in sea level rise in either graph.

    • Lauren R asks which is more accurate, satellites or tide gauges:

      Tide gauges are affected by land subsidence and uplift which should (but probably isn’t) factored out at each location. Satellites are affected by orbital decay and their instruments aren’t accurate enough to determine sea levels with millimeter precision from hundreds and thousands of miles away.

      When tide gauges are averaged together across the globe, the result is more accurate than satellite SL measurements. Averaging numerous tide gauges cancels the effects of uplifting and subsidence (if one or the other predominated, the globe would be getting larger or smaller).

      So tide gauges are the most accurate measurement of SL change.

      Tide gauges show no acceleration in sea level rise — another disconfirmation of man-made global warming claims.

    • Correction to #2 in my post above. Extrapolating the (currently) linear trend of sea level rise to the year 2100 (85 years from now):

      Tide gauge: 0.13 meters or 5.15 (not 1.15) inches

      Satellite telemetry: 0.29 meters or 11.44 inches

      RCP2.6 projection: 0.26 meters (10.24 inches) to 0.55 meters (21.65 inches)

      RCP8.5: 0.45 meters (17.72 inches) to 0.82 meters (32.28 inches)

      James Hansen predicts: 2 meters (6.5 FEET) to 5 meters (16.4 FEET)

      Most of the news articles projecting future disaster are from “studies” that use RCP8.5, except for James Hansen, the Computer Stimulator, who has his head so buried in his own computer models that he’s forgotten to look around and see what the world around him is doing.

      I predict sea level rise around the low end of RCP2.6 even without any action on the part of governments to limit CO2. I won’t be around to see it, so I hope someone checks the Wayback Machine in 2100.

  16. Paraphrasing from another document:

    Climate Researcher’s Disease. “A” releases a bit of dubious research. “B” reads the claim and puts it in his paper. “A” reads the information in B’s report and decides that his information may actually be accurate. “C” picks up “A’s” and “B’s” papers and expands on it creatively. “A” and “B” now both believe their original piece of bullshit is absolutely true. Actually, there’s not a word of truth to any of it. It’s a circle jerk!

    • Not a huge amount, but definitely a measureable amount.
      Also ground water being removed has been known to cause subsidence as well. Venice being one example.

  17. Lets see .5 mm a year sea level rise, that’s about 50 mm a century or 2 inches a century.

    But I am not worried, I have taken immediate action and ordered a pair of galoshes from Amazon .com and put them in a glass case labeled with “Break open for Global Warming Flooding Emergency”

    Geesh I hope the rubber doesn’t go bad in a hundred years.

  18. I have purchased beach front property in the Poconos. I would have been lying out on my new beach waiting for sea level rise to bring in the surf, but it was too cold this weekend as we set a score of new low temperature records in northern NJ.

  19. I didn’t see Nils Axel Morner (sea level data expert) quoted/referenced in the article. Maybe I missed it…Isn’t it data that we want, rather than models? I think he has more data than most of the other names referenced in the paper…

  20. re: Since atmospheric CO2 emission levels do not correlate with such changes prior to the industrial age, the upward trend in temperature and sea level will continue regardless of the political campaign to impose economy-destroying carbon asceticism on the world’s population.

    Whoa, dude.

    1) Rapid coupling between ice volume and polar temperature over the past 150,000 years

    2) economy-destroying?

    Looks like economic growth keeps on fine with reducing carbon emissions.

    3) carbon asceticism?

    Looks like life is better without carbon as an energy source.

    • Those statistics about growth under emissions reductions scenarios are meaningless. Compared to what?
      What was the growth in the 14 years prior to 2000, by comparison.
      Some of the rates of GDP growth are quite lamentable.
      For example, Portugal 1%, Denmark 8% – in 14 years!!!
      China has was growing at between 7% and 13% per year during the same period. Even just 7% per years is a doubling – a 100% increase over just 10 years.
      And you present a country with a 1% increase over 14 years as a country in which, “economic growth keeps on fine”.
      Plus – how do you think that these countries kept their carbon emissions in check?
      Mostly – they have been de-industrialising over the last few decades.
      And so now – China makes all their stuff. Using coal.
      They haven’t really reduced their emissions – they have simply exported them – along with their industry and their jobs.
      I live in the UK. Almost all the consumer items bought by UK are shipped in from the far east.
      The emissions still exist – only they are now taking place somewhere else.
      Check out the youth unemployment rate in Portugal. 35% in 2014.
      Many of these countries you present are teetering in the edge of economic disaster – propped up only by money printing.
      We shall see how long that will last.
      That chart of lacklustre GDP rates that you have presented is intended only for the purposes of tricking fools into believing in make-believe nonsense. But plenty will fall for it.

      • indefatigablefrog wrote: Those statistics about growth under emissions reductions scenarios are meaningless.

        They show that reducing emissions is not economy destroying.

        By providing many counterexamples of economies growing while reducing emissions.

        indefatigablefrog wrote: They haven’t really reduced their emissions – they have simply exported them – along with their industry and their jobs.

        If their industry and jobs have gone, what has grown their economies?

        indefatigablefrog wrote: That chart of lacklustre GDP rates that you have presented is intended only for the purposes of tricking fools into believing in make-believe nonsense.

        What’s your best evidence that moving away from fossil fuels as a source of energy is (and I quote the OP “economy-destroying”)?

        I’m assuming economy destroying isn’t just low GDP growth, nor even a short recession. “Destroy” means “end the existence of (something) by damaging or attacking it.)”.

        That appears to me to be the make-believe nonsense. Do you believe it?

      • Seth provides evidence that the real alarmism here is that which says carbon reduction measures will destroy the economy.

      • So maybe reducing emissions is not destroying the economy. How about if I reduce your bank account. Would you approve of that? After all, I’m not ‘destroying’ all your savings. Just the part I expropriate for my own purposes.

    • Rocky Mountain Institute is your data source for health problems/deaths from coal power plants? I did some work with those people in my composites engineering project. My business partner assessed them thusly: “They don’t know how to tie their shoes.” Biggest idiots it has ever been my misfortune to encounter. Amory Lovins is the false fraud fake flake of all time. Why don’t you donate to them?

      News flash: zero (0.0) autopsies have ever put “Exposure to coal plant exhaust” as a “Cause of Death.”

      “Seth,” your comment is an epic, epic failure…

    • Seth says:

      Looks like life is better without carbon as an energy source.

      Ridiculous. Who feeds you your misinformation? Life is immensely better due directly to fossil fuels.

      • My guess is the Sierra Club or Greenpeace – maybe even the administration or a localized government office. Sea-levels seems to be the coordinated propaganda point right now.

    • The year 2000 was when the internet bubble burst. Much of the growth in GDP after that came from the Housing bubble. What’s the GDP in the US since the EPA proclaimed that CO2 was a pollutant in 2009? That’s a more relevant question.

    • Actually modern technological civilization is based on fossil fuels. They are the biggest boon to humanity since fire. Cheap, affordable energy is the single biggest factor in improving the lives of impoverished peoples.

      So naturally, all these modern Marie Antoinettes want to put a stop to it – to ‘help’ them – while really only catering to their own warm-fuzzy self-image, with no concern all to actual consequences – or worse, to try and deny any responsibility at all with bogus, convoluted bass-ackwards logic (and colorful computer-generated charts, of course) specifically designed to spin and twist themselves into the good guys again. They’re still patting themselves on the back for ‘saving the pelicans’ with the DDT ban – which they didn’t even do, and a few hundred million human beings dead – why that’s nothing to preserve that warm fuzzy.

      Ahh, the warm fuzzy – it’s addictive – like crack. And it’s actually worse, because those who constantly project upon themselves the moral high ground will never stop.

    • GDP is a ridiculous measure of economic output. Government spending counts in GDP even if it is deficit spending. A big part of the decrease in the US has been due to the several recessions we have had since 2000 and the weak-ass recovery the last 8 years. Another big part has been due to natural gas replacing coal due to fracking.

    • Cheap energy is necessary to combat global warming or global cooling, which ever we might experience.

    • Seth, trying like hell to wreck the worlds economy and we still managed to eek out gains. You are the poster child for correlating data. Exactly what the author warns us about. Spectacular. My correlations show the longer Democrats are in the WH, the broker I get. Legislation needed!

  21. Don’t believe your lying eyes, this is just another stealth hockey stick masquerading as a straight line.

    • Yeah, but that data is completely reliable and un-adjusted and clear in its presentation and implications. It tells us quite plainly that there has been an overall approximately linear trend for 150 years. You need to find some way of confusing everything so that you can drive a whole bus full of distortion, confusion and fear into the minds of gullible journalists and then onto the populace.
      You are clearly never going to make it as a climate propagandist!!!

    • How come none of the tide gauges record the mysterious acceleration which started in 1993 when the satellite (adjusted) data comes on-line.

  22. Actual sea-level direct measurement data exist only for a century and a half and only for a few regions of the earth.
    ====================
    The British Admiralty mapped the oceans of the earth in exacting detail 200-300 years ago. These charts show sea level to the closest foot. These charts are still in use today, as most of the earth has never been resurveyed.

    These charts are regularly updated to show wrecks that have occurred since then, rocks that were missed on the original survey, and corrected to match GPS Lat and Long.

    However, nowhere on these charts, on which thousands of lives and perhaps billions of dollars in shipping relies, nowhere on these charts is there a correction for sea level rise. Go figure.

  23. In 2000, Kyra van Onselen wrote a PhD thesis (University of Delft) about “The influence of data quality on the detectability of sea-level height variations” (google ceg_onselen_20010129.PDF for full text). For anyone interested in what can and cannot be learned from studying historic sea-level data it is a must read. The most interesting conclusions are reached in chapter 4, page 89. One key question she tries to answer is when and how a possible increase in the linear trend can be detected in the data. Her conclusion is:

    “Actual tide gauge data contains fluctuations with a wide range of frequencies. It is found that long-periodic fluctuations are the main factor in determining the amount of data required to detect a linear trend in a sea-level height series. … If, after 125 years of data has been obtained, in 1990 an increase in trend occurs, the amount of (future) observations required to detect this acceleration depends on the magnitude of this increase in trend. Without prior smoothing of the data, observations up to 2100 are not sufficient to detect a small trend change from l.5 to 1.8 mm/yr. If trend increases from 1.5 to 4.5 mm/yr (smoothed) observations up to around 2050 are required.”

    To summarize: natural long-periodic fluctuations will mask even a substantial trend change until 2050, and anyone who claims to detect a trend change now is manipulating statistics.

  24. 0.5 mm is 0.020″. In other words, it is 20 thousandths of an inch. Whoever pushes out numbers like this in liquid level measurement belongs in an institution.

    Even 1.4 mm is about 1/16″. This is all nonsense.

  25. I always get a kick out of sea level estimates using tidal gauges, which operate under the very premise that the surface of the earth is a fixed datum on which anything and everything else can be measured. This assumption ignores plate tectonics, whereby the Earth’s surface rises and falls in response to interactions between adjoining plates. Perhaps I’m missing something, but it seems to me that over centuries long time-scales, this known phenomenon has to contribute to the perception via tidal gauge measurements that sea level are rising.

  26. If we can’t handle 2 feet of sea level rise, and have to shut down society in response, then we have become totally feeble. On the US West coast you would not even notice 2 feet of rise. In many places the land is rising anyway and will cancel the SL rise.

    • Even worse, that’s 2 feet over 100 years.
      Most buildings will be replaced at least once over that period of time regardless of what the sea level does.

  27. Yeah . . . NYT. It’s not news. Not one time. Not ever. It’s not what they do for a living.

    I thought everybody knew that at this point.

  28. If just a tiny fraction of one year’s spending ($1 billion+) that is wasted every year on grants to ‘study climate change’ was spent on constructing a world-wide network of a couple of hundred new tide gauges, their measurements could be averaged. That would eliminate local subsidence and uplifting errors.

    Those tide gauge measurements could then be averaged, which would provide a very accurate record of changes in the true mean sea level. It would simply require a sufficient number of tide gauges in appropriate locations around the globe.

    That network of tide gauges would eliminate the subsidence/uplift problem, since there cannot be more of one than the other. Because if that were the case, the planet’s diameter would either be increasing or decreasing, and we know that isn’t happening.

    Will the government do that? Of course not! The government does not want accurate sea level information known, because it would very likely show that sea levels are not rising much, if at all. It would also show that any sea level rise is not accelerating — which is still a claim by some in the alarmist camp.

    The sea level debate is not about science at all. This debate, like the global warming debate, is intended to pave the way for ‘carbon’ taxes. New carbon taxes would confiscate immense piles of taxpayer money, and funnel it into the government.

    That would result in a ballooning of the bureaucracy, paid for by a reduction in the average person’s standard of living. But it would do nothing at all to change either the sea level, or global warming. This entire debate is all about politics, not science.

    The only ones who don’t understand that are the eco-lemmings who have bought into the ‘dangerous man-made global warming’ scare. They have argued for so long, and so forcefully that dangerous AGW is a threat, that they cannot back down now and admit that the hated skeptics were right all along. But it’s true.

    Since the alarmist contingent lost the science debate, it’s become all politics, 24/7/365.

  29. So…beach front property prices are going through the floor? Thought not. Nobody believes this.

  30. I think we should look more closely to WHERE these sea levels do change and how much, because it could serve as an indicator how much northern ice is left..

    Gravity law tells us that due attraction the sea level near an ice cap will be higher. The first ice cap to melt will be Iceland’s, lowering Northwest Europe’s levels – not raising. It is beyond the distance of 1500 km that sea level starts to rise, how more farther away from the melting event how higher the rising will be.

    It is calculated when the ice cap of Greenland will melt, sea levels at the coasts of the UK and Netherlands will rise only 2 meter instead of 4 due this gravity effect. At other hand, all other regions farther away will have an higher rise then computer models are predicting…

    With this theory in hand we should be able to track the ice cap’s doing when we got our sea level data right. Rising levels in NorthWest Europe, little lowering levels in France, and more lowering in Portugal could mean the first ice cap to melt (in case of global warming) is actually growing.

    And to mind boggle myself: if so, how much does a growing Antarctica ice cap lower Northern hemisphere sea level and does this tamper the growing of Northern ice caps (like the couldn’t-sleep-because-of-sharing-a-too-small-blanket-with-someone effect)?

    Does this sound like making sense? ..(Couldn’t find this gravity effect on this site’s archive)..

  31. Meh. The world is experiencing a long term warming trend. You expect ice to melt when it gets warmer. It has little bearing on the case for attribution.

    The fact is that the long term trend has been the same since the exit from the LIA, and was therefore set in motion long before increasing CO2 could have been the causative agent. So, yes, temperatures are rising, and sea level is rising. But, what’s it got to do with CO2?

    Claiming CO2 caused it is not even post hoc ergo propter hoc, because it was the trend that came before. It’s more a basic failure of causality. It’s like claiming cancer causes smoking.

  32. Well,if there has been any appreciable sea level rise recently,it’s probably due to all the eco-nazi panty wetting

  33. I am extremely curious as to how proxy sea level records are deciphered with the precision necessary. Without a tide gauge, how does one determine what the exact mean sea level was at some location and time in the past? Tide lines can give you a maximum high tide, but how do know where low tide was? What effect does climate change have on wind-driven currents and how is that factored in? Subsidence and uplift of the land is also often not a gradual, linear process. The ground can shift suddenly and dramatically in an earthquake, then remain relatively motionless for centuries.

  34. Sea level at The Battery and similar long term measurements have a tab which gives a 50-year average -25 years forward and 50 years back. Many of these show the rate peaks in 1950 or nearby. Satellite graphs show the recent above-trend peak and earlier below-trend dip correlating with the recent PDO, I believe it was.

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