Model Madness: Antarctica’s Effect on Sea Level Rise in Coming Centuries

From NASA JPL:

Thwaites Glacier. Credit: NASA/James Yungel

There are two primary causes of global mean sea level rise – added water from melting ice sheets and glaciers, and the expansion of sea water as it warms. The melting of Antarctica’s ice sheet is currently responsible for 20-25% of global sea level rise.

But how much of a role will it play hundreds of years in the future?

Scientists rely on precise numerical models to answer questions like this one. As the models used in predicting long-term sea level rise improve, so too do the projections derived from them. Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California, have discovered a way to make current models more accurate. In doing so, they have also gotten one step closer to understanding what Antarctica’s ice sheet – and the sea level rise that occurs as it melts – will look like centuries from now.

“Unlike most current models, we included solid Earth processes – such as the elastic rebound of the bedrock under the ice, and the impact of changes in sea level very close to the ice sheet,” said JPL’s Eric Larour, first author of the study. “We also examined these models at a much higher resolution than is typically used – we zoomed in on areas of bedrock that were about 1 kilometer instead of the usual 20 kilometers.”

The scientists found that projections for the next 100 years are within 1% of previous projections for that time period; however, further into the future, they observed some significant differences.

“We found that around the year 2250, some of these solid Earth processes started to offset the melting of the ice sheet and the consequent sea level rise,” Larour said. In other words, they actually slowed the melting down.

The team noted that a hundred years even further into the future – by 2350 – this slowdown means that the melting of the ice sheet is likely to contribute 29% less to global sea level rise than previous models indicated.

“One of the main things we learned was that as grounded ice retreats inland, the bedrock under it lifts up elastically,” said Erik Ivins, a co-author of the study. “It’s similar to how a sofa cushion decompresses when you remove your weight from it. This process slows down the retreat of the ice sheet and ultimately the amount of melting.”

Although this sounds like good news, the scientists say it’s important to keep it in perspective. “It’s like a truck traveling downhill that encounters speed bumps in the road,” said Larour. “The truck will slow down a bit but will ultimately continue down the hill” – just as the ice sheet will continue to melt and sea level will continue to rise.


This animation shows projections of ice sheet retreat in Antarctica over 500 years using the previous models (shown in green) and the new models, which take into account solid Earth processes like the elastic rebound of the Earth (shown in red). The new models show that by the year 2350, melting of the ice sheet and its corresponding contribution to sea-level rise will be about 29% less than what previous projections had indicated for this distant time period. Credit: NASA/JPL-Caltech 

The breakthrough of this study, he added, was to “reach resolutions high enough to capture as many of these ‘speed bumps’ as possible and determine their effects in Antarctica while also modeling sea level rise over the entire planet.”

The study, titled “Slowdown in Antarctic Mass Loss from Solid Earth and Sea-Level Feedback,” was published today in Science.

More information on the study can be found at:

https://vesl.jpl.nasa.gov/sea-level/slr-uplift

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121 thoughts on “Model Madness: Antarctica’s Effect on Sea Level Rise in Coming Centuries

  1. Model presented as fact through the not-so-clever use of folksy interview prose and oh-so-slippery weasel words. Those speed bumps are hard on your credibility.

    • Actually, speed bumps are an extremely poor analogy. Speed bumps actually do very little to slow down a vehicle. It’s the driver’s reaction to the speed bumps – applying the brakes – that slows you down. Without that, speed bumps simply jar your teeth loose.

      • Not to mention increased wear and tear on suspension parts and increased fuel use from the braking and accelerating needed to navigate them.

        • This tells us something significant about NASA. How many climate scientists are developing warp drives there?

      • Not if you hit them fast enough. At low speeds they can be very jarring. At high speeds they are barely felt. Try it. 45 years ago they had them on my university campus. They were high enough that my ’63 Jag E-Type would drag its undercarriage on them. But at speeds of around 45 mph, there was no dragging – and no jarring. It became the only way I crossed them.

        • Spead bumps can be made in any of several configurations: There are the narrow low ones, about 6″ high and 10″ wide, and these can be single bumps or a series of them at some interval. And groups of them can be placed near or far apart.
          Then there are the somewhat higher but much wider ones, about 8-10″ high and 3-4′ wide.
          Then there are the so-called “rumble strips” that are meant more as a signal, meant to alert a driver to something, whether a sharp turn, lane marker, road edge, toll booth, or whatever.

          There is no general rules for how a vehicle will react to such impediments.
          It depends on the vehicle, the speed of the vehicle, the type and size of the bump, etc.
          One size and type of vehicle can react completely differently to another.
          And trailers….fugget about it!
          The larger ones are meant to foil to “go faster” approach, and are often very effective at doing so.
          Groups of them at a calculated interval can cause a vehicle that may be able to ride quickly and smoothly over one, to bounce and bottom out and even to lose control, if going to fast.

        • During my undergraduate years, I was lucky enough to hire on as summer labor at the Chrysler Truck Assembly Plant in Fenton, Missouri. I held several jobs over those summers. One night, I was assigned to drive Dodge vans off of final line to storage in the Castle Yard, about a mile away.

          The intervening road was equipped with speed bumps at regular intervals. I would take a van, drive it to storage, park it, and wait for the gang van to come pick up all the drivers. I soon noticed that I was delivering vans at a far lower rate than anyone else. So I asked one of the other drivers how he did it. He said that I was making the mistake of slowing down for the speed bumps. “If you just get it up to about 60, you don’t even feel ’em!”

          The storage yard was needed because no one was buying Dodge vans (or any other cars) at the time. I think all of the damaged suspensions didn’t help.

        • KK, no need for “high speed” till “They were high enough that my ’63 Jag E-Type would drag its undercarriage on them”.

          Just don’t go at an right angle across them so the tires go BUMM BUMM

          but on some 20 degrees so the tires go BADUMM BADUMM.

          spares suspension and shock absorbers and results in sovereign gliding.

      • “Speed bumps are an extremely poor analogy”
        This is exactly what my first thought was upon reading the article through.
        Agree 100% w/ Mike and Tom.

    • Ah, the old “sofa cushion effect”. I hope they have accurate parameters for that model.

      “Precise” models? Don’t confound that with accurate models.

      We cannot even measure current changes in the ice sheet well enough to know whether total mass is increasing or decreasing, so models have NO ground zero truth. They are just uncalibrated models.

      I suppose it is a good sign that something gets published which is not just another “it’s worse then we thought”.

      • Greg, you are right. I have a scale that is precise, i.e., if I get on in three times in a row, I get the same weight each time. But, the problem is the scale is off by 5 pounds.

        • Bill

          Repeatability, accuracy and precision are different aspects of scale performance. Precision refers to the minimum reported change in mass, for example 20g or 1/4 pound. Accuracy is as you note, related to the reported number being correct. Repeatability is separately reported and for which there is a separate standard rating method.

          Climate models show high precision, high uncertainty, low reproducibility and unknown accuracy. Ice melting and rebound are more predictable than the weather, but that doesn’t help much.

          If there was a solid long term warming trend, ice melt might be predictable a century out, but three? A LOT can happen in three centuries. Look at the last three. Tremendous variability.

          Personally I don’t see why so much fuss is made about sea levels. We are not short of space for humans to live, nor resources, nor inventiveness. The “alarm” is entirely about losing buildings that will be long gone in a century anyway, and perhaps some vague fears that foreigners will relocate – i.e. that they will not prefer to create islands or dikes as the Dutch did.

          According to the alarmist narrative the Dutch should have all trekked into Germany five hundred years ago upsetting and overthrowing the dominant paradigm with their “foreignness”. Instead, they made one of the nicest, richest countries in the world out of a swamp. (It is called the Netherlands for a reason.)

          We should learn from history.

      • precise numerical models

        Someone (John Tukey ?) said something like:
        It is better to have an estimate to the right questions than a precise answer to the wrong question.

        • Exactly.
          I am sure all of these models are assuming as a starting condition that there will be steady warming for the entire time period in question.
          There are many very good reasons to think that Antarctica will gain ice mass in a warmer and more humid world.
          And there are few reasons to think that we will have anything like a steady warming trend in the future, whether over decades, centuries, or over several centuries.

        • Jeff

          That is true in the case of such a device, but I think that is not the item on the floor. A model of ice melting is a lot less certain than a model of paint drying, and twice as boring.

          Given that there is “this model”, then they must have run hundreds of these “1 km resolution” scenarios. So, why are we not hearing about the uncertainty, the sigma 1 value of their spread of results? Is it Normally distributed? Does it have fat tails? Is the median result (average of runs) statistically unlikely with either high or low values more likely? We have to know much more about the model outputs.

          If the model gives the same result each time it is run, it is not model in the usual sense of the word, it is a set of formulas that for any set of inputs gives a single output. In engineering that is a “model” of sorts, but is not accepted until it is validated and given an uncertainty.

          So where are the historically trained inputs and the modern era forecasts from that? If the model cannot be validated it is a “just so” story. I don’t want to demean their work, but we must not attribute to their method skill it is not known to have.

          For example, if the resolution is 1km, the volcanoes should be included both historically as a contributor to melting, and as a future influence. Were they?

          A “precise model” of isostatic rebound is probably a joke in geological circles. It is more like, “It tells me precisely what I expected.”. That kind of “precise”.

      • The “precise” models of anything climate belie the fact that the cumulative error reaches its ultimate limits within as few as 10 years or less. That means they can predict nothing useful. Any mention of 300 years is simply imaginative thinking.

  2. Did they include the onset of the next glaciation in the model? A 300 year projection appears to me a tat little bit overconfident.

    • Instead of glaciers, has anyone looked at water added by being pumped out of aquifers? https://www2.ljworld.com/news/ku/2018/dec/28/heading-out-to-measure-aquifer-levels-crew-expects-to-see-some-decline-from-previous-year/
      Is this higher amount of water and funneling by dikes causing more land erosion?
      Is usable land lost to sinkholes on the rise?
      Is that offset by frakking pumping water into the ground?
      Are we doing enough to dredge river deltas too recover this lost soil?
      How long until climate warriors find this post and add these ideas?
      I see this article discussing above ground ice, but I live near 2019 & 2011 Missouri river flooding, hear about Ogalla Aquifer depletion and Katrina flooding.

      • Ajcross

        Yes the pumped water volume is tracked as a contributor to sea level rise. I was surprised to see it absent in the list above (in the article).

        If the Mississippi floods could be channelled into the Ogallala aquifer, perhaps it would be re-balanced. Easily and permanently.

        • I agree.
          Imagine if even a small fraction of the money spent on worthless climate related studies and wasteful and damaging RE schemes was instead spent on things like constructing rapid infiltration basins for the purpose of recharging aquifers?
          Or setting aside land for diversion of flood waters?
          There are a large number of easily solvable problems that have gone wanting for lack of funding, because global warming/climate change hysteria has sucked all the money away from nearly every other environmental concern.

    • There are certainly a lot of unanswered questions in regards to this new model. Antarctica is so cold that temperatures could rise many degrees and the snow would still fall, and the ice would remain. In fact, the South Pole is currently one of the driest places on earth partly because of how cold it is. The air simply can’t hold water vapor. Any warming would cause significantly more water vapor over Antarctica and thus more precipitation (snow). Is this taken into account in the models?

    • +10 …my second thought as well after wondering how a truck going down a slope while hitting speed bumps can stay on the road.

      • I know!
        Speed bumps do not slow a vehicle, they are meant to force a driver to brake, slowing the vehicle the way it was meant to be slowed.
        If a bump was large enough to slow a vehicle on a slope by any appreciable amount, it would have to be first of all a gradient that was steep enough to overcome all frictional forces, IOW a very steep slope that was producing acceleration merely by gravity, and it would have to be so large it would disrupted the travel of the vehicle, send it bouncing, and likely lose control.
        I think the person who made that analogy has never driven a truck down a slope and hit a speed bump. And only one of my reasons for thinking this is that speed bumps are now placed or designed to do that.
        I would like to hear from someone who has designed or constructed a runaway truck ramp.

  3. LOL so now we are talking about things in 2250 and 2350 based upon conditions today.

    You would think that even the most stupid among us, would realize a quick hindcast of 250 years back in history would tell you the problems in trying that.

    So should we now call Climate Scientists “Fortune Teller”, “Seers” or perhaps “Oracles”.

    Not a large step for Mosher he can add that to his made up titles.

    • Climate Seers

      Climate and the AlGoracles sounds like a really crappy band from the 50’s

    • The thing about these people is, they have accepted, and expect others to, that CO2 is indeed the thermostatic control knob of the atmosphere.
      In fact, they assume it so thoroughly and completely, as well as believing [CO2] will be on an ever upward trajectory, that they do not even bother stating this as a precondition of their modelled “studies”.
      These are people, many of them, who are such good liars, they now believe their own lies.

  4. Antarctica averages more than 40° below zero, so a few degrees of warming obviously won’t melt it.

    In fact, it could have the opposite effect. If sea ice coverage declines in the Southern Ocean, snowfall accumulation on the ice sheet will increase. Evaporation from the open water increases “lake/ocean-effect snowfall” (LOES) downwind. Some of that snow falls on the ice sheets and glaciers, increasing ice accumulation, and offsetting meltwater losses.

    Snow accumulation has a large effect on grounded ice mass, which in turn affects sea-level. In both Greenland and Antarctica, snowfall is the most important factor affecting ice sheet mass balance, greater in magnitude than melting, sublimation, or iceberg calving. In fact, in Antarctica, snowfall accumulation is approximately equal to the sum of those other three factors.

    Multiple studies have found that snowfall accumulation in Antarctica has, indeed, been increasing:

    https://web.archive.org/web/20180104195908/https://www.washingtonpost.com/news/energy-environment/wp/2018/01/03/large-antarctic-snowfall-increases-could-counter-sea-level-rise-scientists-say/

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL075992

    https://www.clim-past.net/13/1491/2017/cp-13-1491-2017.html

    https://www.nature.com/articles/354058a0

    https://www.nature.com/articles/s41558-018-0356-x

    • I doubt that the %age of SH ice is large enough to have an effect irrespective on direction of change. However, warmer water will evaporate more, probably leading to more precipitation on the Antarctic continent.

      SH sea ice has been generally increasing over the length of the satellite record. That is why the never talk about it. Now that NH has not got any lower since they started screaming about its supposed “runaway melting” they have switched to SH but again avoid the inconvenient sea ice, instead focusing on ice sheets.

      They just move the goal posts from one statistic to another as trends change.

      • “Antarctica averages more than 40° below zero, so a few degrees of warming obviously won’t melt it.”

        It’s melting at the peripheries. Via contact with warmer waters where the glacier noses are grounded under water.

        “Multiple studies have found that snowfall accumulation in Antarctica has, indeed, been increasing:”

        It’s expected to.
        Warmer air will carry more moisture.

        “SH sea ice has been generally increasing over the length of the satellite record. That is why the(y) never talk about it. ”

        Antarctic seas are not bounded by land as is the Arctic ocean then each winter ice is free to be wind-blown and expand in area. So there is another function in the mix besides temp. The stronger the wind the further ice can expand before warmer waters melt it.
        The winds around Antarctic have been increasing. Increasing mid-latitude warmth has increased the meridional DeltaT and hence the strength of the jet and so the strength of Depressions circulating the continent.

        https://phys.org/news/2019-04-year-ocean-heights.html

        • Which increasing mid-latitude warmth might that be?
          Over what time period?
          Are you referring to tropospheric or ground based temps? Sea surface or land only?
          Are you conflating the southern hemisphere with the northern?
          Conflating the SH with the entire globe?
          And are you assuming that the highly modelled, adjusted, massaged, “corrected”, extrapolated, infilled, and homogenized time series graphs that are present these days, are somehow an accurate representation of reality?
          Assuming that the people doing all of these adjustment shenanigans have somehow stumbled what the actual case is, making a series of highly biased WAG’s regarding things that were never even measured, or else measured and then “corrected” as much as 100+ years ex post facto?

    • Dave B

      Your third link holds that at the warmest places snow accumulation is the equivalent of 125 cu km per year 2001-2010. This is far more than the historical average gain since 1800. (There is a net gain.)

      The second paper holds that the ice on the continent is melting, which is not the case. There is iceberg calving, but that is a pittance compared with the mass gain in East Antarctica. That is increasing at 5% per year, they report. From everything thing I can find, the ice mass on the continent is increasing, and is not nearly warm enough to melt within thousands of years, if ever. Ever is a long time, of course. Let’s say a few million years.

      Something that is theoretically possible is that the pole, the rotational axis of the lithosphere, changes. This is not impossible. In other words, Antarctica could move north and the ice would melt rapidly. Einstein believed it was possible but we don’t know what conditions would trigger it. It would be sudden. It last happened in 6300 BC with a shift of about half a degree. That wouldn’t change the ice much, if at all.

      In the meantime melting ice-driven catastrophes are not credible.

      • Yes, there are five distinct processes which affect grounded ice mass balance in Antarctica and Greenland:

        1. Snowfall accumulation. This is the largest, most important factor, on both ice sheets, by far.

        2. Sublimation: equivalent to evaporation, but from ice rather than liquid water. It is the reason your ice cubes shrink in the freezer. It is also the reason you can “line dry” clothes up north in the winter (though it’s a slow process): the wet clothes first freeze hard, then gradually soften up as the ice sublimates.

        3. Surface melting and runoff. This only happens if air temperatures rise above 0°C, for long enough that enough ice melts to start flowing off the ice sheet (and/or though it, via crevasses). It happens sometimes in Greenland, so it is significant there, but it’s negligible in Antarctica, except a little bit, occasionally, on the Peninsula.

        (#1 thru #3 are what make up the “surface mass balance” that DMI reports for Greenland.)

        4. Submarine melting, where ice is grounded below the waterline. The freezing/melting point of seawater is about –2°C, and ice doesn’t melt at that temperature, so the ice-seawater interface can be very stable. But if the water temperature is above 0°C then it will erode the ice.

        5. Iceberg calving at glacier termini. This is mostly governed by glacier flow rates, which are governed by many complex factors. There are people who hypothesize that “marine ice cliff instability” could cause an acceleration of this process; that’s at best speculative, if not downright fanciful.

  5. When I was a boy, I measured my rate of growth over a period of 6 months and extrapolated that by the year 2500 I would be 84 feet tall. Tall enough to enact my master plan to once and for all rid the world of green beans and peas (I threw up in my mouth a little bit just thinking about peas) and play center field for the New York Yankees.

    Everything was going according to plan until around 1979 when I turned 18. An anomaly, to be sure. I’m overdue for a major growth spurt. Any day now.

  6. If your a physicist talking about “elastic” rebound your hubris is showing. Go and talk to a geologist. There is “rebound” and a simple negligent conclusion to jump to for it, is not good enough. There is actual material outflow in the upper mantle when pressure is applied to an area of the earth’s surface. The viscosity at a depth of 100km is ~10^20 Pa.s (pascal-second).

    This means that material flows out from underneath the growing ice mass in this extremely viscous medium. Indeed, sometimes more-liquid material (magma that feeds volcanic activity, as that under West Antarcica Ice Sheet and that displaced seaward causes eruption on the seafloor. Recently such volcanic activity has also been discovered southeasterly offshore Greenland.) The better analogy is if you pushed a block of ice down into the water and then let it go -nothing elastic about that.

    “Rebound” is a flowing back (not of the same material where volcanic activity has been involved). This is simply due to the earth gravity effect restoring equilibrium that makes all the large cosmic bodies round in the first place – nothing elastic in that! The imprecision in terminology in climate science (the “folksy” language) in a science paper is imprecision in understanding. It is not a niggle to point this out.

    • Actually there is both an elastic and a non-elastic component to isostatic rebound. The elastic part is quite fast. There is a good description here:

      http://www.skb.com/publication/18722/R-01-41.pdf

      The great weakness in this study is that it does not take into account that West Antarctica is geologically (and rheologically) very different from formerly iced areas in the northern hemisphere (except possibly Iceland).

      • ttyIndeed, the transmission of seismic waves is elastic. Under a sudden shock this higly viscous medium behaves elastically – it oscillates. Slow rates of loading and unloading, not at all so!

      • Hey , what a couple of orders of magnitude between modellers?

        They are only claiming they have a precise model. Not an accurate one 😉

        The main thing is to adjust the parameters for which you have very little real data until your models gives an answer which looks to be about what you expected to find. Then you know it is “right”.

        • Are they providing precise numbers with a highly uncertain uncertainty?

          I am glad they made the effort and that a 1 km resolution gave a different projection from the 20 km resolution. We learned something useful about models.

  7. Well, I wouldn’t call this pure BS, but it is very far from being a “precise numerical model”. That is pure BS. For one thing no numerically precise glacier model yet exists, though they are probably a lot better than climate models (glaciers being intrinsically much simpler physically).

    However their claim for greater precision by using a finer grid-size is nonsensical, for the simple reason that there is simply no GIA (=Global Isostatic Adjustment) data with a resolution anywhere near 1 km, particularly not in Antarctica, where there is very little bedrock available for measurements. Such resolution would hardly be feasible even in Scandinavia where we have 200+ years of high resolution GIA data.

    The GIA model they use is, to their credit, probably the best one there is (see link below) but it has nowhere near enough resolution. And if you check that model, here is the real problem:

    “There are limitations in our approach. For example, we do not account for lateral heterogeneity in viscosity, as our 1‐D Earth structure model represents some azimuthal average. This fact creates a bias that retrieves structure more appropriate to cratonic mantle, where most of the signal is generated and measured (Caron et al., 2017; Nordman et al., 2015). This is problematic when regional viscosity is significantly different, and there has been robust Neoglacial or Little Ice Age mass transfer (e.g., Richter et al., 2016). For example, near the coast of Marie Byrd Land where the upper mantle viscosity is thought to be very low, possibly near 1018 Pa s, our ensemble predicts 1.96 ± 0.65, 1.33 ± 0.49, and 1.64 ± 0.60 mm/yr of uplift, while the observed values are 12.1 ± 2.22, 22.6 ± 2.71, and 37.0 ± 5.5 mm/yr, respectively. “

    The paper is about the coast of Marie Byrd Land. Where their GIA model is admittedly an order of magnitude wrong. And the crux of the whole paper is the effect of the isostatic adjustment.

    Paper here:

    https://science.sciencemag.org/content/early/2019/04/24/science.aav7908?intcmp=trendmd-sci

    GIA model paper here:

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL076644

    • A precise numerical model does not mean it is correct. It can be precisely wrong. Nothing beats a little good data, and we don’t have enough yet to make these kinds of “precise” projections.

    • My precise numerical model predicts that the total mass of ice in Antarctica is 4.242424242424242 e42 nmu

      This is an exactly correct value but unfortunately the conversion factor from new mass units to grams is not known.

  8. “The breakthrough of this study, he added, was to “reach resolutions high enough to capture as many of these ‘speed bumps’ as possible and determine their effects in Antarctica while also modeling sea level rise over the entire planet.”

    Translation:
    We fed our prejudices in minute detail into a supercomputer.
    We did not hind cast to check for model accuracy.
    We did not have any of the code certified for accuracy and verify results.
    We happily used Antarctica rebound from future ice loss. Based on Confirmation bias.

    That is; NASA JPL used GIGO as their operation mantra; Garbage in, Garbage out.

    NASA JPL should be embarrassed.
    Such a waste of supercomputer time.

    • Hindcasting is not really possible. The coast of Marie Byrd land was only mapped during the 1940’s.

      Though it might be a good idea to test-run the model on the deglaciation of Iceland after the Younger Dryas where there is reasonably good data and a reasonably similar geology.

      The code might be certified, but there are really no data with the required resolution, so it really doesn’t matter whether the code is good

    • “… while also modeling sea level rise over the entire planet.”” for hundreds of years periods. I weep.

  9. One word: “validation”.

    How did they validate this model?

    Did the even try to validate this model?

    • Validation by noble cause was invoked for the good of the people. The model confirms the biases of the consensus of the respondents. 🙄

  10. Here in Québec we currently experience unusual flooding. Politicians, média, etc repeat ad nauseam « Climate Change » …until one journalist asked one climate specialist from Ouranos which is a « Mannesque » institute who whispered: « Our models predict the opposite »

  11. How can they predict on such a long run the Sun activity, the volcanic activity, the impacts of oceanic pseudo oscillations, atmospheric circulations, Milankovitch cycles, etc. ?

    The fact is that we can’t even correctly predict what will be the next ENSO (El niño or La niña, its strength ?) …
    and NOT ONE of the former climate related doomsday predictions turned to be right.

    Did they even bother to acknowledge that they can’t take those unknown into account ?
    In these conditions, a model precision is meaningless and claiming otherwise is either idiotic or snake oil salesman’s practice.

    My BS meter is skyrocketing.

  12. It’s an obvious attempt to give the model more credibility today, by finally showing something that is not as bad as we first thought, several hundred years from now.

    However, the models do NOT have any credibility when it comes to SLR or temperature rise and some studies show that Antartica is still gaining ice mass, meaning it’s currently reducing sea levels.

  13. Come along now JPL, this is nowhere near alarming enough. Speed bumps? Seriously, WTF?? How is that supposed to induce panic? Better to say that the weight of the ice is the only thing that keeps continent of Antarctica in place, and when all the ice has melted in 2030 the whole thing will succumb to the pressure from beneath and flood the planet with molten magma. We don’t want no prissy “speed bumps”, we want impending doom, and much sooner than 2250 for gods sake. Did you not read the memo?

  14. The same ole same ole. They live in their virtual computer generated climate and we live in the real climate. They claim their models can accurately project out decades and now even centuries when we see that weather model ensembles more often than not can’t get it right even a month out. But nothing will persuade the true believers. An exchange I had with one of the faithful over at Dr. Spencer’s blog when the dreaded “Polar vortex” was descending upon us in the Midwest: http://www.drroyspencer.com/2019/01/dangerous-record-breaking-cold-to-invade-midwest-chicago/

    Rah says:
    February 1, 2019 at 1:29 AM
    Less than a month ago the US and European weather models were forecasting most of the Midwest and Eastern US to have higher than average temps during this period. But we are to believe that climate models projecting what conditions will be years and decades out are accurate and base policy decisions having huge effects on the fate of our nation and people on their projections? I think not.!
    bobdroege says:
    February 1, 2019 at 1:04 PM
    Back in the 40s F for the weekend, so on average for the period, may be higher than normal.
    Grew up in Chicago area, it was know to go for a month without going above freezing.
    And climate models and weather models are apples and oranges.
    rah says:
    February 1, 2019 at 9:24 PM
    bobdroege says: “And climate models and weather models are apples and oranges.”
    Both exist to attempt to project or forecast future conditions accurately. That’s apples and apples PERIOD!
    And I don’t care what the average in Chicago will be for “the period” because it is irrelevant to my point.
    The point of my message was that if weather models can be so terribly wrong when forecasting less than 30 days into the future then climate models which are projecting much further into the future are much more likely to be terribly inaccurate. After all climate is just the prevailing weather conditions of a particular area or region over a longer period of time.
    Thus it is foolish to make public policy based on the output of climate models.

  15. There are two primary causes of global mean sea level rise
    ===========
    1.adjustments
    2.more adjustments

  16. The number of useless eaters living off Climate Change is really astounding.
    But, somebody has to absorb the excess wealth produced by our modern industrial economy. And, verily, this type of useless eater will reduce the production of wealth by our modern industrial economy, and so, using my precise computer model, climate change science will be extinct in, say, 50 years.

  17. No matter what happens, it’s going to be 100% positive for humans. Climate change concerns can now come to a complete halt.

  18. Pretty tough to fight back when the alarmists have all of government and their resources behind their efforts. Kudos to scientists out there who legitimately practice the art of science in their efforts to inject some legitimacy into the process.

  19. Fred
    Good quip.
    These “modellers” live in a world of fantasy within which they can’t distinguish between real and unreal.
    I’ve been a professional in the financial markets for more than 50 years and see the same thing.
    At around 1964 economists began to have access to mainframe computers and the “modelling” started. Samuelson and others really believed they could end recessions.
    This was little different to the reasoning behind the formation of the Federal Reserve System. Bankers in the early 1900s knew that financial setbacks preceded recessions. The Fed, as “lender of last resort” would prevent the setbacks and this would prevent recessions.
    There has been 18 recessions since the Fed started intruding in January 1914.
    But the belief in a central bank with supernatural powers continues.
    The problem is “modelling” and the same blunders prevail in climate as has prevailed in economics for generations.
    Sad.

    • Ah yes Fortran punch cards and a DEC10 were going to solve all the problems of the world with econometrics and now it’s eco-metrics. Economic theory couldn’t even predict the next economic boom or bust let alone unprecedented stagflation the consensus being before that you either had inflation or deflation. High unemployment with high inflation? Can’t happen until it did just like The Pause eh chaps?

      The only correlation you can really trust is computer development and human hubris.

  20. “We found that around the year 2250…

    even further into the future – by 2350

    Why are they even bothering?

    We only have 12 years to save the planet – Washington Post

    We have 12 years to act on climate change before the world as we know it is lost. – The Independent

    We have 12 years to limit climate change catastrophe, warns UN – The Groaniad

    BBC Two‏
    Verified account

    @BBCTwo
    Follow Follow @BBCTwo
    More
    With just 12 years left to save the planet, here’s @RachelParris on why we CAN’T let the world go floppy!

    Looks like a consensus to me.

  21. Aside, from the questions I have about the model specifics, it is worth noting that computer simulations and mathematical/statistical models are important tools in science and engineering. In fact, modern engineering would be impossible without them. This site’s dedication to model bashing has become a major discredit to the important business of climate skepticism.

    • I retired a few years ago after spending most of my working life in aerospace where, among other things, I worked with developing, testing and using computer models. Admittedly they were for modelling flight operations and logistic processes which are a lot simpler to model than climate.
      Even so we thought we were pretty good when our predictions were within 20% of the actual results, and so did our customers.

      And I am a climate model basher. Among other things because models with more than two, or at the very most three, parameterized variables are utterly useless. The reason: you can get any result you want by “tuning” your parameters (and within quite reasonable ranges). You are only fooling yourself.

    • So SLC Dave you defend using climate models with a limited and poor history of accuracy as a viable foundation to base governmental policy on? Really?

      • Why don’t you read what he actually wrote?
        He said nothing of the sort.

        What he’s complaining about is something that I have often complained about. Many people here assume that since climate models are worthless, therefore all models are worthless, and nothing could be further from the truth.

        • Somehow I have3 missed “this site” bashing models used in engineering or for most other purposes other than climate. Wanna show me where “this site” did that?

          • Once again, would you please read what was written.
            I said nothing about “this site” bashing non-climate models.

    • I’m another who uses models in my work – electronic circuits.
      Models are often optimised to (and do) perform better (i.e. closer to reality) under certain conditions than others. It will do exactly what the model builder wants it to do.
      They are very useful but results must always be verified by building the circuits.
      Often experience suggests which condition is (and which is not) more likely to yield a helpful result.
      And even then if it doesn’t match, shoulders are shrugged and another idea is tried.

      In the case of climate models my layman’s impression is that they have been designed with an over-emphasis on the effect of CO2 in order to get some aspects to be closer to reality.
      And even then they aren’t very.
      And if they don’t match shoulder shrugging won’t fix the effects that the preposterous solutions to the non-issue are (already) having.

      Don’t build your climate house on model sand!

    • SLC Dave

      I look at results from Monte Carlo simulations for making some financial decisions.
      There are lots of other great uses.

  22. “Antarctica’s ice sheet is currently responsible for 20-25% of global sea level rise.”

    Not if Antarctica is currently gaining ice mass as a NASA study suggests. On the other hand there are large lakes beneath the Antarctic ice that must feed groundwater to the ocean. The gold standard of SLR remains Walter Munk (now emeritus) at Scripps: An Enigma, too little, too late, and too linear; meaning we are missing something.

    A good candidate for the missing something is groundwater.

    • “Not if Antarctica is currently gaining ice mass as a NASA study suggests”

      Depends is snow accumulation exceeds ice lost at contact with warmer waters.

      https://climate.nasa.gov/news/2836/antarcticas-contribution-to-sea-level-rise-was-mitigated-by-snowfall/

      “A new NASA-led study has determined that an increase in snowfall accumulation over Antarctica during the 20th century mitigated sea level rise by 0.4 inches. However, Antarctica’s additional ice mass gained from snowfall makes up for just about a third of its current ice loss.

      “Our findings don’t mean that Antarctica is growing; it’s still losing mass, even with the extra snowfall,” said Brooke Medley, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, which was published in Nature Climate Change on Dec. 10. “What it means, however, is that without these gains, we would have experienced even more sea level rise in the 20th century.”

    • MarkW
      “Until you understand how everything affects everything, you don’t know nothing.”
      So because we don’t know everything about some things, what we think we do know about these “some things”…… is wrong? HUH??? That is such a classic BS skeptic tactic.

      • Simon:

        It is “staggering”.
        Like mankind has got where we are by knowing everything before we acted.
        Staggering indeed.
        What’s the point in any study of possible future events then?
        Given that we cannot know “everything”.
        We don’t know the weather forecast will be correct exactly for us next tuesday.
        But we know a hell of a lot more than if there were no weather forecast.
        Such that, say, we can make appraisal of contingencies based on probabilities.

      • Not BS, reality.
        Unless you understand ALL of the feedbacks in a system, trying to describe how the system will respond to a perturbation is an exercise in futility.
        Either that or a deliberate lie by people who should know better.

  23. Stop the presses on the multi-century forecasts! The science isn’t settled.

    These papers are surprising news, contrary to the doomster narrative. I doubt that either will be mentioned in the mainstream press or the liberal websites (that report every doomster paper as gospel). Red emphasis added.

    Non-uniform contribution of internal variability to recent Arctic sea ice loss” by Mark England in Journal of Climate, in press.

    “Over the last half century, the Arctic sea ice cover has declined dramatically. Current estimates suggest that, for the Arctic as a whole, nearly half of the observed loss of summer sea ice cover is not due to anthropogenic forcing, but due to internal variability. …”

    A new 200‐year spatial reconstruction of West Antarctic surface mass balance” by Yetang Wang et al. in JGR Atmospheres, in press.

    “High‐spatial resolution surface mass balance (SMB) over the West Antarctic Ice Sheet (WAIS) spanning 1800‐2010 is reconstructed by means of ice core records combined with the outputs of the European Centre for Medium‐range Weather Forecasts ‘Interim’ reanalysis (ERA‐Interim) and the latest polar version of the Regional Atmospheric Climate Model (RACMO2.3p2). The reconstruction reveals a significant negative trend (‐1.9 ± 2.2 Gt yr‐1 decade‐1) in the SMB over the entire WAIS during the 19th century, but a statistically significant positive trend of 5.4 ± 2.9 Gt yr‐1 decade‐1 between 1900 and 2010, in contrast to insignificant WAIS SMB changes during the 20th century reported earlier. …”

  24. The National Institute for Standards and Technology could end this contretemps in a week. The entire farcical “issue” of Global Warming/”Climate Change” is all based on ignoring the rules of data that all engineers learn. Calibrate the instruments! All of them, thermometers, satellite altimeters, GRACE satellites, ARGO buoys, right down to the buckets used by the Royal Navy to measure ocean temps starting in 1851.

    Guess what: NONE of these have been calibrated, with the possible exception of the United States Historical Climate Network. NONE of the models have been validated. NIST pro’s must be either bemused or disgusted by what they witness, but they remain silent, not wanting to be politicized.

    We let them do their jobs, and they are quite good at this, it all goes away quickly. “Climate Scientists” must secretly be terrified by this prospect. The Hockey Stick was publicly flamed by McIntyre, who would be a really good NIST guy. They have lots more McIntyre’s.

  25. Stop the presses! The science isn’t settled.

    Both of these papers are contrary to the doomster narrative. I doubt that either will be mentioned in the mainstream press or the liberal websites (that report every doomster paper as gospel). Red emphasis added.

    Non-uniform contribution of internal variability to recent Arctic sea ice loss” by Mark England in Journal of Climate, in press.

    “Over the last half century, the Arctic sea ice cover has declined dramatically. Current estimates suggest that, for the Arctic as a whole, nearly half of the observed loss of summer sea ice cover is not due to anthropogenic forcing, but due to internal variability. …”

    A new 200‐year spatial reconstruction of West Antarctic surface mass balance” by Yetang Wang et al. in JGR Atmospheres, in press.

    “High‐spatial resolution surface mass balance (SMB) over the West Antarctic Ice Sheet (WAIS) spanning 1800‐2010 is reconstructed by means of ice core records combined with the outputs of the European Centre for Medium‐range Weather Forecasts ‘Interim’ reanalysis (ERA‐Interim) and the latest polar version of the Regional Atmospheric Climate Model (RACMO2.3p2). The reconstruction reveals a significant negative trend (‐1.9 ± 2.2 Gt yr‐1 decade‐1) in the SMB over the entire WAIS during the 19th century, but a statistically significant positive trend of 5.4 ± 2.9 Gt yr‐1 decade‐1 between 1900 and 2010, in contrast to insignificant WAIS SMB changes during the 20th century reported earlier. …”

  26. I have a very precise, accurate, highest resolution model that says you are a witch!

    Must be more truer than ever!

    I mean… It’s a MODEL!

  27. I would think that a truck hitting speed bumps while traveling down an incline would soon lose stability, and run off the road.

  28. Other than the above thought, my assessment of future conditions is that the current Warm Period will give way to cooling either side of 2200. These guys are nuts to think that the climate system will never cool again.

  29. Are they providing precise numbers with a highly uncertain uncertainty?

    I am glad they made the effort and that a 1 km resolution gave a different projection from the 20 km resolution. We learned something useful about models.

  30. Catch-22 for all you melting glacier alarmists: the faster a glacier runs out into the water and calves huge icebergs, the more ice that will have to be melted by the warm ocean waters. Thus, the thermal expansion will be partly checked by more ice. Furthermore, that cooler water means more CO2 will be absorbed by the ocean’s water, and HEAT WILL NO LONGER BE TRAPPED AT THE SAME RATE! [1] Ergo, sea level will not rise as much as they fear.

    Ba-BAM! In your face, alarmists.

    [1] – the author of this comment personally rejects the notion that CO2 in the atmosphere “traps heat” and that small shifts in atmospheric CO2 concentrations drive major climate shifts on planet Earth.

  31. I have just purchased a block of land with a beautiful vies on the North Face of Mt Everest so I no longer need to worry about these impending sea level rises.

  32. As this paper come from the Jet Propulsion Laboratory does this mean it is a load of hot air?

  33. It appears you ignored the effect of magma intrusion from sub aerial volcanoes on sea level?

    This must be around 2.8 x10^12 cubic metres pa, if population is roughly 100,000 over 1Km high, in their main/established phase of 28×10^6 m^3 pa average emissions. Less if we low ball this established estimate to 50,000, close to the population of Pacific Atols we can see above the surface, never mind the rest that didn’t make it the average 10,000 oceanic feet – just for scaling cred. The estimate I use for active oceanic volcano population is the University of Oregon’s, their average emission volume of 28×10^6m^3 p is from Scott White’s paper. This is certainly in the right order/space, on the facts we have measured, so know.

    Crucially the low ball 50,000 population arithmetic delivers a surface displacement upwards of 3 or 4 mm pa over 362×10^12m^2 ocean surface area, less depending on how much the 7Km wafer thin oceanic crust is depressed by the added weight of the sea floor, pulled into the visco elastic upper mantle by gravity, hence the 10-30 KBar pressure under it.

    Just saying. Following the agenda of others as to causes while also ignoring significant real effects can create unsupportable beliefs ;-). Favouring what you think is causing the effect at the expense of what you consider insignificant, or exclude arbitrarily, rather than allowing all possible effects to be separately assessed by the experimenter is Cargo Cult Science 101, as applied in climate science. Doing the arithmetic objectively quickly quantifies this significant effect, left totally ignored, or falsely denied as “insignificant” without the evidence of arithmetic. No it isn’t. Details here if you are interested, in Table 3, all input data and maths is transparent in the text.

    Call me sceptical … but no denier of the provable facts.

    So corrections of fact with references and arithmetic are very welcome.

    I may be wrong, It’s easy to fool yourelf. But I believe sub aerial volcanoes havesome significance for our problem.

    PS I do realise the sea floor is being subducted into the mantle so that basalt and limestone deposits are continuously recycled out of new volcanoes as CO2 and water vapour in the radioactively heated furnace beneath. But the volume involved in the necessary planetary crack filling is a few ten’s of 10Km^3 pa, far less than the sub aerial magma emission of 2,800km^3 from volcanoes that penetrate the faults in tectonic slabs. (74,000km of divergent plate boundaries, x 0.00007m pa average x 7km deep = 36Km^3 ……….. and yup, I ignored flood basalts from the join). This is not even in my number, because it is filling a gap. The number I calculate is for the estimated population of sub aerial volcanoes alone.

  34. KK, no need for “high speed” till “They were high enough that my ’63 Jag E-Type would drag its undercarriage on them”.

    Just don’t go at an right angle across them so the tires go BUMM BUMM

    but on some 20 degrees deviant so the tires go BADUMM BADUMM.

    spares suspension and shock absorbers and results in sovereign gliding.

  35. Re. speed bumps. In the early 1950 tees my brother and I rode a BSA
    650 cc twin bike over most of Australia. Back then outside of the Towns
    and Cities it was all dirt roads. We used to say that at night little green
    men came out and dug all the pot holes and the bumps, which naturally
    occurred.

    We found that if we kept our speed at 60 mph it was not too bad, the bike
    would ride from the top of one bump to the top of the next one, and the
    suspension took it ok. Of course cornering could be interesting.

    Oh happy days.

    MJE VK5ELL

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