Sea Level

Sea Level Is Not Rising Faster Than Researchers Previously Thought

Despite alarming headlines to the contrary

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Sea Level Manhattan
marineinsight

The United Nations Intergovernmental Panel on Climate Change's (IPCC) Synthesis Report released just last November concluded:

Over the period 1901–2010, global mean sea level rose by 0.19 [0.17 to 0.21]m (Figure 1.1). The rate of sea-level rise since the mid-19th century has been larger than the mean rate during the previous two millennia (high confidence). It is very likely that the mean rate of global averaged sea-level rise was 1.7 [1.5 to 1.9] mm/yr between 1901 and 2010 and 3.2 [2.8 to 3.6] mm/yr between 1993 and 2010. Tide-gauge and satellite altimeter data are consistent regarding the higher rate during the latter period. It is likely that similarly high rates occurred between 1920 and 1950.

Global mean sea-level is increasing according to the IPCC because glaciers are melting on land and the added heat from man-made global warming produces thermal expansion in the oceans.

A new study published in Nature this week, using models incorporating fancy new statistical techniques, finds that the IPCC has slightly overestimated the rate of sea-level rise during most of the 20th century. This new study has provoked some interesting headlines. For example, the Washington Post reports, "The rate of sea-level rise is 'far-worse than previously thought,' study says" and The Independent warns, "The tides are changing: Sea levels rising at faster rate than predicted, study finds.

The new study finds between 1901 and 1990 that sea level rose by 1.2 millimeters per year instead of the IPCC rate of 1.7 millimeters per year. In other words, instead of rising by 6 inches over the course of the 20th century sea level rose only 5 inches. The Nature study reports that the rate of sea level rise increased to 3 millimeters per year between 1993 and 2010. Note that the IPCC reports an increase of 3.2 millimeters per year between 1993 and 2010.

So if the new study turns out to be correct, the rate of sea level rise in the last two decades did indeed accelerate more than the IPCC reported, speeding up from an annual rate 1.2 millimeters rather than a rate of 1.7 millimeters.

On the other hand, the new report finds a slightly lower rate of increase in the past two decades than does the IPCC (though both are pretty solidly within the error bars of the other). In any case, sea level rise is not "far worse than previously thought" and since these are not predictions but empirical data, it is also not "rising at a faster rate than predicted."

Assuming the 3 millimeter per year rate in the new study, that suggests that average sea levels will be about 10 inches higher than they are now by the end of this century, or about double the increase over the 20th century.

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  1. “Assuming the 3 millimeter per year rate in the new study, that suggests that average sea levels will be about 10 inches higher than they are now,”
    By when, Ron?

    And:
    ” In other words, instead of rising by 6 inches over the course of the 20th sea level rose only 5 inches.”
    Missing the word “century”?

  2. A new study published in Nature this week, using models incorporating fancy new statistical techniques, finds that the IPCC has slightly overestimated the rate of sea-level rise during most of the 20th century.

    Deniers!

  3. You guys are ringing the retard bell on this one. Cue Tony’s sophistry in four, three, two, one….

  4. “I guess we might have been overzealous in our eagerness to state the catastrophic nature of global warming.”

    – No One in the Environmental Movement

  5. I’m starting to think they need a new word to use instead of “study”. In my opinion, putting together a model, and comparing it’s out put to data, and deciding that the data is likely incorrect, is not really what I think of when I hear that a “study” was published. It’s more of a barely substantiated guess, that may spur a future, useful “study”, using actual data.

    1. Exactly. They threw out the coastal measurement data of sea levels, and conjured up a scientific number based on imputed average ocean levels over the surface of the Earth.

      Not only are they throwing out the coastal data, they’re overlooking the fact that’s it’s coastal sea levels people are most worried about, because they live on the coast.

  6. “Just because every prediction we make is wildly wrong, don’t pre4tend panic is not justified.”

    1. Human activity is harming the planet because human activity is harming the planet! The logic is irrefutable!

      1. My opinion has been swayed; I find what you say convincing and would like to subscribe to your newsletter.

  7. Damnit! I was counting on the sea to free me of NYC!

  8. Maybe I’m drastically oversimplifying, but do we have to believe the IPCC anyway? They cheated on measuring land temperatures by putting thermometers on hot pavement. How’d they get their ocean rise statistics?

    1. They cheated on measuring land temperatures by putting thermometers on hot pavement.

      Seriously? I hadn’t heard of that. If true, it is a new low for scientific inquiry.

      1. This was a claim by deniers. It was discredited as the temperatures are apparently corrected for the effects of the immediate environment.

        1. WTF does that mean?

          Temperature reading – hot pavement temperature = correct temperature?

          1. WTF does that mean?

            However, when processing their data, the organisations which collect the readings take into account any local heating or cooling effects, such as might be caused by a weather station being located near buildings or large areas of tarmac. This is done, for instance, by weighting (adjusting) readings after comparing them against those from more rural weather stations nearby.

            They’ve allegedly compensated for the effects of location and it is certainly doable. Still doesn’t account for 17 years of no warming.

            I just don’t think thermometer placement is a credible argument.

    2. Sorry, but I can’t take seriously estimates of sea level rise (or fall) when it’s in millimeters. I don’t see how anyone can come up with figures that small when the ocean moves much more than that from tide and wave action on its own.

  9. putting together a model, and comparing it’s out put to data, and deciding that the data is likely incorrect

    “According to my model, my model is correct. I can’t help it if the world is wrong.”

  10. So if the new study turns out to be correct, the rate of sea level rise in the last two decades did indeed accelerate more than the IPCC reported, speeding up from an annual rate 1.2 millimeters rather than a rate of 1.7 millimeters.

    This acceleration is particularly puzzling, since it occurred when global temperatures had flatlined.

    What’s the theory on why sea levels rose at a slower rate when global temperatures were trending up, and rose at a faster rate when global temperatures were steady?

    1. Essentially, from reading a summary, they estimated ice melt, and modeled sea level through it. A couple quotes: “Scientists now believe that most of the world’s ice sheets and mountain glaciers are melting in response to rising temperatures.” Hay added. “Melting ice sheets cause global mean sea level to rise. Understanding this contribution is critical in a warming world.”

      1. they estimated ice melt, and modeled sea level through it.

        As opposed to just frickin’ measuring the sea level itself? WTF?

        Melting ice sheets cause global mean sea level to rise.

        And apparently they melt faster when temperatures are stable than when they are rising?

      2. Did the IPCC or the Nature study pull that crap?

    2. Tectonic activity.

      That’s my first guess, since it’s not temperature dependant and can change the shape/depth of the sea.

      1. An expansion of terrestrial land mass through processes such as the Rift Valley spreading?

    3. Basically, they are trying to say that they’ve invalidated actual measurements, through a model…

      1. What are you going to believe? The measurements, or the experts? Do you think those measurements are smarter than the experts? Because those experts are really smart!

        /Tony

        1. I wish he had come here to say something similar. In this case it’s a recent Doc grad, and a post-doc fellow, challenging the experts. But since that challenge fits the narrative, it was published, despite a significant lack of merit.

          1. Wouldn’t matter. He’s stated on numerous occasions that the only people he trusts are scientists, with scientist being defined as someone who works for the IPCC.

            He reminds me of this dumbshit cook I used to work with who simply could not comprehend concepts or principles. We would serve several stuffed chicken dishes. Each one being a butterflied breast with some stuffing pressed into it, baked, then topped with a sauce. Well, to him each one was a distinctly separate recipe. Change the sauce or stuffing, and he had to learn it from scratch. Simply couldn’t comprehend the concept of it being the same technique with different ingredients.
            Tony is like that. He simply cannot comprehend principles or concepts. Everything has to be specific.
            Therefore if you know science and apply it on a daily basis, but it isn’t climate science and you don’t work for the IPCC, then you know nothing at all.

    4. The rise in sea levels is essentially a function of many variables, most of which affect the density of the water, some of which affect the mass of the oceans.

      This includes tectonic movements (eg the continentals shelf under me is rebounding a milimeter or so a year (IIRC: too lazy to look up) from no longer supporting the last ice age’s glaciers), local temperature changes, current/river flow changes, salinity, and temperature.

      Because ocean currents move so slowly, the transport of heat from the surface to the deep ocean takes years to play out.

      For temperature based sea rise, one would expect a significant lag between atmospheric temperature increases and the rise of sea level due to thermal expansion.

      The catastrophist religion’s prophecy is that the rising temperatures will melt ice that is currently on the land, such as the Antartic and Greenland ice sheets. This will dump a slug of cold fresh water into the nearby oceans.

      The meltic ice immediately would cause a significant rise in sea level. They fear that the cold fresh water would also stop or alter a bunch of significant ocean currents resulting in a change in heat transport that would have large climactic impacts (eg plunging temperatures in northern europe because the gulf stream isn’t warming the air reaching them).

      1. Hansen (the CAGW movements main prophet) predicted famously in the 90’s that by 2030 Manhattan would be inundated. The rise in sea level was supposed to be the primary driver of the economic harm that justified forcing fuel poverty on the world. The fact that sea level continues to rise more or less consistently at the same rate since the early 19th century has been a major thorn in their side.

        Their prophecy has made many predictions, none of which have come true, and they are truly desperate to point to something, anything, that doesn’t refute their superstitious fears.

        1. Doomsday cults are adept at moving the goalposts.

        2. Additionally, sea level rise seems to have slowed in the past decade. It’s been right around 3mm/yr for a pretty long time, and fairly certainly that in the 90’s. It’s down to about 2.5mm/yr between 2000 and 2010.

          Not only are temperatures failing to rise as predicted, ice is failing to melt, and seas are failing to rise as much as predicted.

        3. The fact that sea level continues to rise more or less consistently at the same rate since the early 19th century has been a major thorn in their side.

          The article says it is rising faster now than then.

          It should be noted the Arctic is melting, and Greenland does have SOME melting. The Antarctic ice sheet is also losing mass, although that might be based entirely on GRACE data which I do not think is totally reliable.

      2. The rise in sea levels is essentially a function of many variables, most of which affect the density of the water, some of which affect the mass of the oceans.

        The thing about models is that they are a function of their variables. The fewer variables, the more accurate the model can be.
        Modeling something like artillery trajectories has a few variables, and the results are accurate.
        Modeling something like the climate has a potentially infinite number of variables, so any model is bound to be wrong because it’s just too damn complicated to make accurate predictions.

  11. 1: How was the sea level measured in 1910?
    2: How was it measured in 2010?

    1. That’s what I mean by my comment up yonder. One could also ask:

      1. How do legitimate scientists measure sea level?

      2. How does the IPCC measure sea level?

      1. Yeah, those are good follow ups; ultimately, I’m not as concerned with the method as the consistency, as well as ensuring any natural variables (erosion, displacement, etc.) are compensated for while measuring.

        So yeah, I doubt how they measured sea level in 1910 was “good,” or correct, in any way that would allow any kind of accurate comparison.

  12. AGW is supposed to be about atmospheric warming, not ocean warming.
    It takes a hell of a lot more energy to warm the oceans than the atmosphere.

    1. Last I heard, they abandoned atmospheric warming when the atmosphere refused to cooperate, and declared that the oceans are where all the extra degrees are going. Deep ocean, mind you, not the surface waters where any bozo can dip a thermometer.

      1. But to measure ocean temps they just dip a thermometer in at noon right next to the beach, because taking a boat out is a lot of work.

      2. Too bad the recent study of the ocean categorically found no deep warming although there was some surface warming.

        1. Too bad the recent study of the ocean categorically found no deep warming although there was some surface warming.

          I’m sure no correlation was done or made with thermal (non)-expansion of the oceans either.

          They always seem to skip the really exciting model vs. model death matches.

  13. One point seven millimeters over the entirety of the ocean.

    Really? That level of precision over a body that is in constant shifting motion?

    No.

    And all due to ‘global warming’.

    No.

    Like every other bit of leftist insanity, eventually it just becomes too absurd.

    1. Not to mention specific location of the Moon, which requires knowledge of exact distance.

      1. Thinking about it a bit more, I’ve decided we don’t have the information nor tools necessary to make an accurate measure of ocean depth.

  14. the added heat from man-made global warming produces thermal expansion in the oceans.

    The oceans are disappearing the heat.

  15. Regardless of whatever petty scientific disputes may arise over predictions, models, causes, effects, and evidence, we still must give numerous third-world dictators billions in cash else we’re all doomed.

  16. I smell heretics deniers.
    /Jackland Ace

  17. my classmate’s aunt makes $66 /hr on the internet . She has been without a job for seven months but last month her payment was $18218 just working on the internet for a few hours. check it out…..
    ????? http://www.netpay20.com

  18. You racist bastards. Obama CLEARLY stated at his nomination that this was the time that would be remembered as the moment when the rise of the oceans slowed. AND HE HAS CLEARLY delivered on that promise. And you knuckle-dragging, obstructionist teathuglican RACISTS can’t even give him the credit he deserves….

    THERE IS JUST NO PLEASING YOU PEOPLE!!!!

  19. my co-worker’s mom makes $75 every hour on the laptop . She has been fired from work for ten months but last month her paycheck was $13904 just working on the laptop for a few hours. use this link………..
    ????? http://www.netcash50.com

  20. Not to worry. When the last major glaciation ended, about 11,500 years ago, the sea levels rose about 300 feet. Considering that Arctic sea ice levels are up (and the polar bears are doing just fine) and Antarctic ice amounts are greater than ever, I don’t think we have to worry about anything the IPCC has to say. In fact, over the last 2 million years, or so, scientists have established that the Earth goes into a major glaciation period for about 100,000 years, followed by an inter-glacial period of between 10,000 and 12,000 years. All of this is caused by the Sun and Earth’s orbital variations. And if you believe that human-caused CO2 causes global warming / climate change then I’m betting you believe in the Tooth Fairy, Easter Bunny, and Santa Claus, too.

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