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Earth Science

Scientists Cut Greenland Ice Loss Estimate By Half 414

Posted by samzenpus
from the not-so-bad-after-all dept.
bonch writes "A new study on Greenland's and West Antarctica's rate of ice loss halves the estimate of ice loss. Published in the journal Nature Geoscience, the study takes into account a rebounding of the Earth's crust called glacial isostatic adjustment, a continuing rise of the crust after being smashed under the weight of the Ice Age. 'We have concluded that the Greenland and West Antarctica ice caps are melting at approximately half the speed originally predicted,' said researcher Bert Vermeeersen."
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Scientists Cut Greenland Ice Loss Estimate By Half

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  • Global warming? (Score:2, Insightful)

    by Anonymous Coward

    Quick! Change the name!

    CLIMATE CHANGE!

    Yeaaah! Then we'll be able to claim we're right, even when we're wrong! woo!

    • Re:Global warming? (Score:4, Interesting)

      by fiannaFailMan (702447) on Thursday September 09, 2010 @12:10PM (#33524186) Journal

      Quick! Change the name!

      CLIMATE CHANGE!

      Yeaaah! Then we'll be able to claim we're right, even when we're wrong! woo!

      Correct me if I'm wrong, but wasn't it actually the right wing and their petrochemical backers who popularized the phrase "climate change" to squeeze the words "global warming" out of the debate?

  • Great news! (Score:4, Insightful)

    by Arancaytar (966377) <arancaytar.ilyaran@gmail.com> on Thursday September 09, 2010 @04:08AM (#33518368) Homepage

    This estimate change means climate change has once again been proven wrong! Right? Right?

    (Hint: No.)

    • Re:Great news! (Score:5, Insightful)

      by Thanshin (1188877) on Thursday September 09, 2010 @04:16AM (#33518406)

      This estimate change means climate change has once again been proven wrong! Right? Right?

      (Hint: No.)

      No, it's just a change in one of the thousands of indicators. However that's only for the people who actually care for the science of climate change.

      For the rest, this estimate will prove just about anything between the third coming of the messiah and the imminent destruction of the Earth by magnetic core spin reversal.

      • by interkin3tic (1469267) on Thursday September 09, 2010 @05:22AM (#33518722)

        For the rest, this estimate will prove just about anything between the third coming of the messiah and the imminent destruction of the Earth by magnetic core spin reversal.

        Hey now! Some of us just believe one or the other, that this is a sign of Jesus' return, or that the Earth's magnetic core is going to stop. It's only a lunatic fringe of our organizations that believe ice loss means Jesus is coming to stop the Earth's magnetic core!

        • Science! (Score:4, Funny)

          by DarthVain (724186) on Thursday September 09, 2010 @09:17AM (#33521220)

          "....and what also melts?"

          "Cheese?"
          "small stones!"
          "toasters!"
          "witches"

          "That's right! Witches. Now who doesn't like Witches?"

          "Water?"
          "DUCKS!"
          "Jesus?"

          "Correct! Jesus hates witches... and what happens when messiah returns?"

          "Frogs?"
          "Mice?"
          "The Destruction of Earth!"

          "Very good, the destruction of earth! Now what does the earth do now?"

          "Rotates around the sun?"
          "Hosts Life?"
          "Spins?"

          "Yes it spins! Therefore when it is destroyed, it will stop spinning. What is created by spinning?"

          "Centrifugal force?"
          "large rats?"
          "Magnetism!"

          "Correct, it creates magnetism, which must cause the destruction of earth due to its stopping by Jesus because he hates witches. Quid Pro Quo."

          "Applause!"

      • Re:Great news! (Score:4, Insightful)

        by OeLeWaPpErKe (412765) on Thursday September 09, 2010 @05:46AM (#33518824) Homepage

        Actually it just means that once again the new prediction for sea level rise falls outside of the 95% confidence interval reported in the IPCC reports. Again. Imagine the chances. They've made 3 predictions, all with 95% confidence intervals, and the new prediction falls out of all 3 of them (just like their next prediction fell outside the 95% range for their previous prediction, both for sea level rise and temperature, so actually we should square the 5%). So if their chances are accurately calculated, that they're this wrong should happen once in 10y * 1 / ( 5% * 5% * 5% ) = 80 000 years.

        I'm not a global warming denialist, mind you ... this obviously means that for the next 80 000 years the IPCC will not make a single wrong prediction !

        Actually this is really smart of those scientists. You see, once every 80 000 years they will make 3 sequential predictions, each wrong. It's like, really smart of them to do it right away, then they can be right for the next few dozen millenia ! Brilliant !

        • Re:Great news! (Score:5, Insightful)

          by ShakaUVM (157947) on Thursday September 09, 2010 @06:31AM (#33519090) Homepage Journal

          >>They've made 3 predictions, all with 95% confidence intervals, and the new prediction falls out of all 3 of them

          That's why I especially like one prediction they did (in AR4, I think) that included no change in the predicted models for 10 years out within the error bars (which was something like +0C to +4C).

          So even if there's no climate change, it verifies climate change.
          But if there's +5C change, then, by golly, global warming has been falsified! The results didn't match prediction.

          In all seriousness, though, I think there's a real paradox in what we consider falsification and verification in science if the above two statements are both true.

          • Re:Great news! (Score:5, Informative)

            by Chris Burke (6130) on Thursday September 09, 2010 @09:32AM (#33521498) Homepage

            So even if there's no climate change, it verifies climate change.
            But if there's +5C change, then, by golly, global warming has been falsified! The results didn't match prediction.

            In all seriousness, though, I think there's a real paradox in what we consider falsification and verification in science if the above two statements are both true.

            Yes, there's a problem with what you consider falsification. Falsification applies to theories, not to observations.

            If the temperature rises 5C, it would falsify the theory by which we model and predict global warming. However, the observation of global warming would be stronger than ever. So, we'd have to change our theories.

            It's similar to how experiment falsified the Caloric theory of heat because the result did not match predictions, but did not falsify the concept of heat. Observations that did not match Newton's Law of Gravity did not "falsify" the observation that gravity exists.

            On the other hand, a temperature change of 0 degrees, that would validate the theory by which we model and predict global warming. However the observation would be of no global warming for that period. It would be correct to say "there was no global warming in this ten year period". Just remember that unlike a theory or model, this would not "falsify" the previous observations of warming.

        • Re: (Score:3, Insightful)

          by Thanshin (1188877)

          I'm not a global warming denialist, mind you ... this obviously means that for the next 80 000 years the IPCC will not make a single wrong prediction !

          You're not very strong at probability either. ;)

      • "No, it's just a change in one of the thousands of indicators...."

        After reading up on post-glacial rebound, it appears the conclusion that the ice is melting half as fast is completely backwards.

        So, lets assume that a 1000m thick glacier melted down to 500m over the last 50 years, judging by elevation readings on the surface of the glacier. But now we add a rise of 250m of the underlying rock due to post-glacial rebound over that same 50 year period. That means the glacier actually thinned by 75%, not the 5

        • Re: (Score:2, Informative)

          by Anonymous Coward

          yes, you missed something: the details of glacial/crust rebound.
          They explained that all movement isn't just moving up - some is sideways, some is down.
          what is happening is that N. America is rebounding up for the last 20,00 years and this
          has actually pulled Greenland over/down.

      • Re: (Score:3, Insightful)

        by Anonymous Coward

        What about the people that suggested the 'accepted truths' were extremely alarmist and that using such hyperbole to get a point across would be incredibly damaging to future efforts at swaying hearts and minds towards making things better?

        Do we get an apology for being called deniers?

    • We all know from measurements that the north pole (and Greenland) was warmer than average - we know that from direct measurements.
      We all know that the ice is still melting (but slower than we thought).

      So, I conclude that all our books regarding heat transfer must be wrong ;-)

      • Re:Great news! (Score:5, Insightful)

        by TapeCutter (624760) * on Thursday September 09, 2010 @05:02AM (#33518642) Journal
        "We all know that the ice is still melting (but slower than we thought)."

        Given we know the rate of ocean rise with a high level of certainty. The interesting thing about this estimate is that it has flow on effects to other estimates, such that the amount of ocean rise due to thermal expansion could be higher than previously thought which could mean that the oceans thermal inertia is not as slow as we thought.
        • Re: (Score:2, Insightful)

          by OeLeWaPpErKe (412765)

          Since when do we know that ? Sure we know what we see on a few coastlines (quite a few, granted). We do not, however, have anywhere near accurate 3d heatmaps of the ocean, so we have no clue at all what is causing the variations, since to say the least, the ocean is an interesting place when it comes to temperature variations (and not just temperature variations, there's acidity, salinity, and a dozen other things that all influence eachother).

          • Estimates for total sea level rise are from both tidal gauges and sattelites, the largest error bars for these mesurements I can find are +/-0.7mm/yr

            There are two major components that contribute to the observed rise, thermal exapansion and melting ice. If the estimate for the molten ice component goes down then given the estimated rise in sea level has not changed the estimate for the thermal expansion component must go up, no?

            I don't see why you need 3D thermal heat maps to calculate a simple percen
        • Re:Great news! (Score:4, Interesting)

          by Psychotria (953670) on Thursday September 09, 2010 @06:00AM (#33518892)

          The amount of ice is dependant on altitude. I am sure that the climatologists know this, but just because the rate of melt at sea level is increasing doesn't mean that the amount of melt at moderate or high altitude is as well. If the average global temperature increased then the average air pressure would decrease meaning that snow and ice at higher altitudes would increase (due to the freezing point of water being dependant on air pressure). Therefore there will be an increase in snow/ice as you move up in altitude. So, the rate of melt might even remain constant.

          • Re: (Score:3, Informative)

            by Psychotria (953670)

            Correction: the average pressure would increase

          • Re:Great news! (Score:5, Insightful)

            by paeanblack (191171) on Thursday September 09, 2010 @07:53AM (#33519656)

            If the average global temperature increased then the average air pressure would...

            It would do nothing along the lines of what you are thinking. The atmosphere is not enclosed in a rigid container (external force), but held by gravity (body force).

            The average pressure at sea level is the gravitational weight of the atmosphere divided by the surface area of the earth. The classical mass of the atmosphere is independent of average temperature.

            Yes, local temperature changes cause local pressure changes. This does not mean global average temperature changes cause global average pressure changes.

      • Re:Great news! (Score:5, Informative)

        by elbow_spur (749878) on Thursday September 09, 2010 @06:07AM (#33518934)
        > We all know that the ice is still melting (but slower than we thought).
        This year we are going to see a new record low for arctic sea ice --- surpassing even the dramatic 2007 decline.
        http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png [uiuc.edu]
        What's really startling is that this year, both the NE and the NW passages are completely open. This animation tells the story
        http://arctic.atmos.uiuc.edu/CT/animate.arctic.color.0.html [uiuc.edu]
        Typically, shipping through the NE passage relies on Russian icebreakers. Judging by the satellite photos, at this point the icebreakers aren't needed
        Source: cryosphere today http://arctic.atmos.uiuc.edu/cryosphere/ [uiuc.edu]
        • Re:Great news! (Score:5, Informative)

          by dtjohnson (102237) on Thursday September 09, 2010 @09:12AM (#33521102)

          This year we are going to see a new record low for arctic sea ice --- surpassing even the dramatic 2007 decline.

          No one can say with certainty what 'might' happen...but it can be said
          what has already happened with arctic sea ice extent...and you are
          wrong. Arctic sea ice extent this year is greater [uaf.edu]
          than it was on the same date in 2007 AND 2008.

             

          • Re: (Score:3, Insightful)

            by ScentCone (795499)
            Please do not disturb him with annoying distractions such as observations of actual ice.
  • Not really! (Score:3, Insightful)

    by sd4f (1891894) on Thursday September 09, 2010 @04:17AM (#33518408)
    I think it just means that in reality, science hasn't got all the right answers, all of the time, and science should be treated, as it was always intended, with a grain of salt.
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      It means that science is not to be confused with religion and changes in estimates of anything should be studied and understood and not used as a pretext to dismiss science itself as unreliable. If you prefer 'stability' over the truth then you either need religion or counselling. Or both.

    • Re:Not really! (Score:5, Insightful)

      by interkin3tic (1469267) on Thursday September 09, 2010 @05:33AM (#33518768)

      science should be treated, as it was always intended, with a grain of salt.

      Are we talking "grain of salt" as in "not taking it so seriously" or "understanding that some changes to scientific theory and predictions are bound to occur."

      Not taking science seriously, such as thinking maybe the law of gravity won't really apply this time so you can jump off that building, or not really caring whether or not global warming is occurring is dangerous and fairly illogical. Understanding that scientific theories often change with new facts, but that those changes don't mean the whole thing is bunk, that's good.

      • by EdZ (755139)
        More that the phrase "scientific consensus" is a load of balls, science doesn't work that way. There is no 'consensus', just an as-yet-undisproven theory that most accurately explains the current observations and makes testable predictions. That most scientists will accept that this theory as 'correct' [tufts.edu] is a byproduct of the theory being accurate, not the other way round. Questioning whether a theory is correct (i.e. attempting to find observations that do not correlate with the theory's predictions) is the
        • Re: (Score:3, Insightful)

          What do you mean "science doesn't work that way"? Peer review is a vital part of science. You can't prove a theory 'correct', but that is not a claimed goal anyway. Scientific consensus on a theory just tells you that a given theory matches the data provided up to that time. The longer a theory stands the more data is accumulated that either supports or data com,es out that the theory needs to be revised.

          In the case of TFA they revised how fast Greenlandic ice is melting, but it is still melting at non-tr
        • Re: (Score:3, Insightful)

          by oiron (697563)

          That there are people who blindly ignore evidence in their attempt to smear a theory with inconvenient predictions muddies the waters, and results in our current state where anyone who so much as questions any data or theory on anthropogenic climate change is an "anti-science global warming denier", and the slightest correction to data is "proof of the gubernment conspiracy", with BOTH of these being a detriment to actual climate science.

          Those who raise new questions (like this study) are skeptics who advance the scientific method. Those who keep bringing up the same old "but they believed in global cooling in the 1970s" crock are deniers. There's a difference.

      • by PopeRatzo (965947) *

        Are we talking "grain of salt" as in "not taking it so seriously" or "understanding that some changes to scientific theory and predictions are bound to occur."

        No, we're talking "letting climate scientists do their work without turning every single datapoint into a cudgel with which to pound lumps on your political enemy.

        Especially if your expertise in climate science consists of learning to compile a Linux kernel.

        Have you noticed that nearly everyone with a lick of sense has learned to completely stay away

    • Re:Not really! (Score:5, Insightful)

      by Tom (822) on Thursday September 09, 2010 @07:53AM (#33519660) Homepage Journal

      I think it just means that in reality, science hasn't got all the right answers, all of the time, and science should be treated, as it was always intended, with a grain of salt.

      I don't think you understand what science is.

      This paper is science. There is not the slightest reason to disbelief in science even the tiniest bit because one prediction has been replaced by a better prediction - because that is exactly what science is all about. Science is a highly successful method of getting ever closer to whatever the "right answer" may be, by falsification, replacement, improvement.

      That real revolution in thinking has not yet made it into our ape brains. We enjoy the successes it has given us, from technology to medicine to psychology, diplomacy, social sciences, practically everything around you except sunday church and friday flirting is heavily influenced by science. But few of us have made scientific thinking our home. When was the last time you stopped yourself in a fight with your girlfriend to re-examine the facts and try to actively falsify your hypothesis about her reasons?

      Our ape brains want to verify, we feel more secure if we think we are right. Science wants to falsify, to show that the model is wrong, in as much detail as possible, so we can make up a new one that is better.
      Or in less individual and more social terms: Religion starts by postulating a few facts, and then killing everyone who disagrees. Science starts by postulating a few axioms, and then trying as hard as possible to show that they're wrong. On those that survive, we build more theories, again trying hard to show they're wrong.
      For geeks: Science is like crypto. An untested cipher is considered weak until enough time has passed and enough people have tried breaking it that everyone else accepts that "we" as a hole don't - at least yet - know a way to do it, so for the moment it's a good cipher.

      So to bring it all full circle: This is an improvement of the climate change models, and disproves them in the same way that finding a good attack on RSA breaks cryptography. It doesn't, breaking ciphers is an important part of cryptography.

  • Scientists (Score:3, Funny)

    by Hognoxious (631665) on Thursday September 09, 2010 @04:18AM (#33518422) Homepage Journal

    Scientists are wrong again, just like they were about magnets.

    • Re: (Score:3, Insightful)

      by Thanshin (1188877)

      Scientists are wrong again, just like they were about magnets.

      Just as wrong as they were about every single thing except those they've not yet been proven wrong about.

      The method's kind of based on being provable wrong so, everything's going as planned. Nothing to see here unless you know how to interpret the new data.

      i.e.: The news are, on themselves, useless but as a heads up for the result that will come shortly.

    • Re: (Score:3, Insightful)

      by Crypto Gnome (651401)
      Scientists are always wrong.

      That is, until one of them gets it right.
  • by BlueParrot (965239) on Thursday September 09, 2010 @04:35AM (#33518512)

    Some bright researchers managed to refine a previous model and come up with better and more accurate predictions. You may want to note how, contrary to some "skeptics" beliefs this wasn't suppressed or refused publication or any other such shenanigans. In the word of a famous person "When I'm proven wrong I change my opinion, what do you do ?".

    • by Yvanhoe (564877)
      That's why there is a culture clash when they have to work with politicians. By changing opinions, scientists increase their credibility, by doing he same, politicians lose it. Expect fights.
    • by ShakaUVM (157947) on Thursday September 09, 2010 @06:26AM (#33519062) Homepage Journal

      Some bright researchers managed to refine a previous model and come up with better and more accurate predictions. You may want to note how, contrary to some "skeptics" beliefs this wasn't suppressed or refused publication or any other such shenanigans. In the word of a famous person "When I'm proven wrong I change my opinion, what do you do ?".

      An honest skeptic would look at the Greenland melt data and say that there wasn't enough evidence. An honest Al Gore would have looked at the Greenland melt and put large error bars around his predictions. Dishonest people on either side refuse any results that disagree with their presumptions.

      I recall watching CSPAN and seeing climatologists talking about how the Greenland melt rate would be 10 times greater than we'd expected, because of the wet pancake effect or something. I'm not an AGW skeptic, though I *am* critical of idiots like that, that claim more evidence than there is. He's up there scaring senators, and... he's wrong. (Or probably is - the Greenland melt is an active area of research.) I'm also critical of people like Sarah Palin who think that human beings can't possibly, ever, affect the climate.

      Unfortunately, it seems most people are dishonest dogmatists for one side or another.

    • by argStyopa (232550)

      All very well and good. It's how things are supposed to work in science. I'm delighted that the models are being refined.

      Of course, one might also note that shrill histrionics, cries of impending certain doom, and politically motivated proto-religious hyperbole aren't necessarily "science at work".

  • TFA says Greenland is subsiding due to mass moving to North America. I was thinking that due to the melting, the crust would be rising and thus hiding the apparent ice loss.

    Very interesting...

  • It is time for the global cooling crowd to make a comeback and breathe some fresh air into the stale old climate debate.
  • OK, so people are trying to argue that this paper supports one view or another in a trivial manner. I don't think it's that simple.

    I can't even being to interpret what this means without a lot more reading. I'm not even sure I know all the questions that need to be asked. But here's a couple which occur to me immediately...

    1. This is a new method of measuring ice loss, and from what I can tell is rather hard to interpret given the interacting phenomena. There are long established methods which are far simpl

    • by Yvanhoe (564877)
      1. speed of ice flows give you the mount of ice that leaves the system. You also need to register the amount that enters it. It is expected to see ice flows in Groenland, the question it to know if the ice is renewed through snow/rain.

      2. How do you measure sea levels ? It is also a very hard matter when you want to reach a centimeter or millimeter precision. Shores erode, oceanic beds move tectonically. Satellites can measure the distance between the gravitation center of Earth and the sea's surface but
  • Conveyor (Score:3, Insightful)

    by overshoot (39700) on Thursday September 09, 2010 @06:37AM (#33519114)
    Looks like I can reset my clock on the anticipated shutdown of the Atlantic Conveyor.

    Less fresh water in the North Atlantic means the thermohaline convection effect will be keeping Europe warm and wet for a while longer. In the short term, that's good. In another sense, though, I suspect it's not so good: it's going to take something dramatic to move climate change out of the "we'll worry about that when we don't have anything more important" category.

  • Check for yourself (Score:3, Insightful)

    by thethibs (882667) on Thursday September 09, 2010 @04:06PM (#33527456) Homepage

    This is something anyone on Slashdot should be able to do. First, go get the GISP2 ice core data at

    ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt [noaa.gov]

    Pull the data into Excel or R or your favourite tool and plot the most recent 10,000 years (period since the end of the last ice age). You'll find it easier to interpret if you convert the age to years AD and BC and normalize the temperatures to make them relative to current.

    You'll see that the Mann Hockey Stick is right where it's supposed to be. What's surprising is how tiny it is (said the actress to the bishop).

    What I find most interesting is that, since 8000BC, it's only been as cold as it is now three times, and for each time only 200 or so years. So is it going to get warmer? Yeah, that's a safe bet if we don't get an ice age first. It's going to get a lot warmer before it gets to what's been normal and comfortable for most of modern human history.

    Does Mann demand an explanation? No--there's nothing exceptional about the current trend--it doesn't require an exceptional explanation. It's just the climate being the climate.

    The next thing I did was superimpose the rise and fall of the great human cultures in both the Old World and the Americas, with a focus on equatorial civilizations. With a couple of exceptions, they all get their start during warming periods. A few, the Hittites, both Romes, Islam, see their fortunes literally rise and fall with temperature.

    But don't take my word for it. It's an hour's work to see for yourself.

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