09 February 2012

Glaciers are not melting as fast as was thought

Excerpts from an article in The Guardian:
The world's greatest snow-capped peaks, which run in a chain from the Himalayas to Tian Shan on the border of China and Kyrgyzstan, have lost no ice over the last decade, new research shows. The discovery has stunned scientists, who had believed that around 50bn tonnes of meltwater were being shed each year and not being replaced by new snowfall...

The scientists are careful to point out that lower-altitude glaciers in the Asian mountain ranges – sometimes dubbed the "third pole" – are definitely melting. Satellite images and reports confirm this. But over the study period from 2003-10 enough ice was added to the peaks to compensate. The impact on predictions for future sea level rise is yet to be fully studied but Bamber said: "The projections for sea level rise by 2100 will not change by much, say 5cm or so, so we are talking about a very small modification." Existing estimates range from 30cm to 1m.
This is going to lead to lots of misunderstandings, because there are a variety of nuances and caveats in the interpretation of the data.  Posted here so those interested in climate change controversy can start reading up on the new findings.  What amazes me is the methodology -
The new study used a pair of satellites, called Grace, which measure tiny changes in the Earth's gravitational pull. When ice is lost, the gravitational pull weakens and is detected by the orbiting spacecraft...
It's hard for me to comprehend how the effects of gravity created by mountains can be altered by superimposed snow accumulation, or how such differences can be measured.  I'm not doubting, mind you - just having trouble comprehending.

Addendum:  A hat tip to whoever posted in the Comments the link to this video, which discusses this phenomenon (and these results) in detail.

24 comments:

  1. Well I think it's more about glacial ice than snow. Ice has much more mass. That said, I don't really understand it either.

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  2. I hope the miusnderstanding and confusion is felt mostly on the side of those who originally claimed "the science is definitive, there can be no questioning of the science!!"
    As a warming hysteria skeptic, I've always felt that the "nuance and caveats" were stronger than the conclusions drawn. The systems in question always seemed more complex and intertwined than the was allowed by the ALGORE's simplistic (and very profitable it turns out) declarations of impending doom.

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    1. The planet *is* warming, so the science remains quite correct. All this says is that in certain areas the loss of ice was less then expected. You see, that's how science works, it corrects itself and adjusts as new facts are discovered. You will notice that it's those same scientists who are giving you this info, not the skeptics or the right wing think tanks they work for. The denial "scientists" (who usually have oil company ties) are still quite rightly dismissed.

      http://en.wikipedia.org/wiki/Science

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  3. I am always struck that any data which leads to questioning of the global warming doomsayers requires "nuances and caveats in the interpretation of the data".

    When data that is claimed to support global warming is presented any attempt to examine the "nuances and caveats in the interpretation of the data" is rejected.

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  4. The quest to understand how the Earth's climate works is still quite a young field of science, still very much in its data-gathering period, so I'd stay pretty skeptical about any sort of forecast (good or bad) for the moment. But these findings can't be a bad thing (I imagine).

    To get back to Grace though (since at least that is something we can say we do understand), any mass added to a certain point on the Earth will increase the gravitational pull around this point. A satellite passing overhead will "feel" that as a small increase in the force pulling it towards the ground.

    Now what has to be understood is that there is a two-way relationship between that force and the speed at which it travels forwards.
    You can think of it as when you spin a sling, the faster it moves the harder it pulls. It's the exact opposite thing that happens with satellites, the more the Earth pulls on them, the faster they move (hence near-earth satellites move much faster than say, GPS or telecom satellites).

    So if you put two satellites in formation on the same orbit and very precisely measure their relative distance, you can see a change in the mass as a "bump" in the distance measurement (as the 1st satellite speeds up and is then caught up by the trailing one).

    With this method and the incredible precision with which Grace can do these distance measurements, it can detect changes in mass of the order of one part in one billion.

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  5. Replies
    1. Nice link, Steve. People should click on it. Most relevant to this discussion are the graphs that clearly show overall that ice is melting. The title of Stan's post is unfortunately misleading, in that glaciers are definitely melting. The only new info, and surprise, is that the ice is mostly melting at lower altitudes, while the stuff at the tops of mountains hasn't changed much.

      But is this really surprising? We in the northern latitudes are all familiar with how snow melts. When spring comes, the snow melts first in the warmest areas -- in sunny spots, off poorly-insulated roofs, next to windows, the ocean, etc. And the snow lingers in cold spots -- in shady spots, near frozen lakes, in deep valleys, etc. Is it any surprise that -- despite global warming -- snow might linger longer at the colder tops of mountains?

      -Chuck

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    2. Is that the same NASA that made all those promises about how cost effective the shuttle was going to be? Is that tha same NASA that killed 14 astronauts? Is that the same NASA that could not polish the Hubble Mirror correctly. Is that the same NASA that lost a Mars satellite because the failed to convert metric to English measurments?

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  6. I don't think anyone disagrees that the Earth is warming, thankfully, otherwise we'd still be under ice. The question has always been 1) is Man the major cause of the warming (I'm skeptical), 2) can Man avert the warming (I'm skeptical) and 3) if Man can avert the warming, should he (I'm skeptical of that last one, too). I think we downplay the benefits of the warming since the ice melted and don't fully appreciate how good we have had it.

    The percentage of CO2 in the atmosphere is so, so small... and then Man's contribution to that percentage is so small.. and the question of whether CO2 increases because it's warming or whether it's warming because of the increase in CO2... is quite debatable.

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    1. Pretty much everything you mentioned is covered here by these guys that are pretty smart...NASA. Shall we listen to the folks that successfully put man on the moon, rovers on Mars, and are sending things out into deepest space, or paid "skeptics" and denialists who collect their paychecks and grant money from oil companies and think tanks?

      Climate Change: Evidence"

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    2. Dan, while I really can't answer your last question (if Man can avert the warming, should he) very well, let me try. The climate IS changing, and that can mean that if small areas of this planet suffered drought in the past, that could very well mean that large areas of the planet could suffer through drought in the present, and in the future (such as our current winter here in the United States, as opposed to the winter that Europe is going through), and usually drought is accompanied by heat waves (aka Texas, summer, 2011).

      So to answer your first two questions, which is worse? Do we act as if Man is NOT the major cause of climate change, and so therefore do nothing, and therefore greatly increase the negative effects if Man IS the major cause of climate change. OR, do we act as if Man IS the major cause of climate change, and possibly reduce the negative effects, even if Man is not the major cause? I say lets act as if Man is the major cause of climate change, because at least that way, we (or our ancestors) can say that we did everything in our power to prevent the changing climate.

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    3. "I say lets act as if Man is the major cause of climate change, because at least that way, we can say that we did everything in our power to prevent the changing climate."

      Civilization as we know it is predicated on hugely inefficient energy sources - particularly coal and fossil fuel energy generation (~33-50% efficiency before accounting for line loss and the inefficiencies of the devices consuming the electricity) - and even renewable sources require an initial energy investment (which almost invariably is coming from non-renewable sources).

      Taking responsibility for climate change starting right-this-minute would mean a radical re-imagining of what it means to be a human being - consider what it would mean for the average American's lifestyle (and prospects of raising children) if 99% of the energy (fuel, electricity, food) his or her present lifestyle demands were no longer available for consumption.

      Tangential: If they ever make an electric SUV, I don't want to live on this planet anymore. Oh.

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    4. You all ignore or downplay that if Man can reverse the temperature trend of the planet, that action has consequences; consequences quite possibly more severe than warming, on the other end. I suspect this is because you realize that Man really cannot reverse the temperature of the planet and you are thus not worried about being buried in ice. And no, I find climate analysis quite out of the scope of rocket science, and NASA isn't the same organization that took us to the moon. And even if it was, the moon shots were short sighted, spectacle-goaled, propagandized events... which is why America is now stuck on Earth waiting for the future.

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    5. You all ignore or downplay that if Man can reverse the temperature trend of the planet, that action has consequences; consequences quite possibly more severe than warming, on the other end.

      You're actually afraid that if "man" makes efforts to be less wasteful and destructive in his energy use that he might "refreeze" the planet? I have to say, that's one I've never heard....... lol.

      You do know that most of the data involved takes into account the ice age and CO2 levels and warming since right?

      Since NASA, and the scientific consensus of nearly every respected scientific organization in the world isn't satisfactory to you, who would you suggest is your authority on the subject? I mean you're essentially doing the equivalent of saying the world is flat, and engaging in anti-intellectualism and expecting us to take it seriously.

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    6. I didn't say anything about Man's wasteful and destructive energy use. Scientific consensus is seldom worth a thing when you look back on it in hindsight, why do you put so much faith in it now? Look, if you believe Man is causing the CO2 increase, there is no way possible, let's be real, to reduce our footprint the amount needed to change the planet... the goals are outlandish and can only be achieved by either running out of coal and oil in the near future (which we won't) or by an energy breakthrough (magic). The only other option is carbon sequestration or releasing bacteria or (as Freeman Dyson said) carbon eating plants... both options have dangers greater than warming.

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  7. I believe this study was based on data from the GRACE satellite. The description of how it works is quite amazing. They gauge gravity anomalies by measuring minute variations in relative acceleration and deceleration of two satellites called "Tom and Jerry" that follow each other in orbit. They can "see" when the Amazon Basin is experiencing its wet season by measuring the extra weight of the water in the vegetation and floodplain. This should also be a very accurate way of observing ice loss where it really matters, on Greenland and Antarctica, by detecting annual changes in ice mass. http://en.wikipedia.org/wiki/Gravity_Recovery_and_Climate_Experiment#How_GRACE_works
    http://www.csr.utexas.edu/grace/publications/fact_sheet/

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  8. What study?
    Why is there no damn source in the Guardian article? How difficult is it to put a link to a study?
    In the absence of it, the only reasonable way to react is with much skepticism.

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  9. Just did a bit of research and found the answer to my previous question, and happened onto a quite interesting video to put these results in context:

    http://www.youtube.com/watch?v=JJSA0iZ_xeA

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    1. Nice find. I've bumped the link to the video up into an addendum to the post.

      Thanks for your research - it's a well-done analysis and presentation.

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  10. The planet has been warming and cooling for billions of years. We are sure proud of ourselves to think that in the hundred years since we developed the internal combustion engine, we could change the climate. Even more hubristic to claim that we could now reverse that change. Try taking a geological time viewpoint... Ten thousand years ago detroit was under a mile of ice.

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  11. I don't know if it is still of any use to post a comment here, but anyway:
    I would just like to address the apparent skepticism of a few people about global warming. There is an overwhelming scientific consensus that not only is it happening (no one seriously argues with that anymore), but that human-emitted CO2 is the main driver.
    Naomi Oreskes published an essay in the journal Science, in which she tested that claim. (Full article: http://www.sciencemag.org/content/306/5702/1686.full)
    She looked for all the peer-reviewed papers she could find on climate change and read the abstracts to see what the position of the authors was on the issue. 75% of the papers agreed with the consensus, 25% were not relevant to current climate and hence took no position, which leaves 0% in disagreement.
    And before anyone says that this has been rebutted by Klaus-Martin Schulte, I know, and here's an abstract of his rebuttal: http://multi-science.metapress.com/content/d588k23724201502/ (Ironically, the full paper is not available for free)
    But here's a rebuttal of the rebuttal: http://www.skepticalscience.com/news.php?n=6
    Now I'm not saying that there is no possible debate, but that the position of a great majority of the scientists who study this for a living is that man is responsible for global warming. Sharing this opinion is not evidence of pride, but of humility.

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  12. There is just too little CO2 in the atmosphere to drive the amount of warming predicted by the models. They all use a fudge factor to multiply the effects of CO2 and in no way does that fudge factor have the kind of scientific consensus you describe. The consensus is all about whether the planet is warming and whether Man is contributing CO2 to the atmosphere.

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    1. Dan, could you please point me towards a peer-reviewed scientific paper in which I could find this alleged "fudge factor"?
      Your personal claims are not enough to make me doubt the scientific consensus which is (and I reiterate this point) that human-emitted CO2 accounts in a statistically significant manner for the changes in the climate that have been observed in the last century.

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