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Himalayan glaciers |
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| Nov13-09, 05:15 AM | #18 |
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Himalayan glaciersThis discussion paper cannot reasonably be considered an equivalent to peer-reviewed scientific literature, IMO. It is explicitly a discussion paper. Furthermore, previous application of the guideline has explicitly noted that this forum is not a place to develop new ideas. "The goal of PF is to help students learn the current status of the different fields of science, as practiced by the scientific community." That is my understanding, per this ruling from Monique: The problem (as I see it) in Earth science is that there is a lot of stuff bandied around which is distinctly fringe, and not actually part of what is practiced or considered by the working scientific community -- particularly relating to climate. At the same time, there are a lot of active dispute and open research questions which ARE part of the normal ongoing working scientific community. If you read the web, you can get everything from extreme crackpottery, to simple minded misunderstandings or errors, to isolated maverick ideas, to fringe notions by competent amateurs which have not yet had any impact, to minority views that are being pursued within the working scientific community, to wide open research questions. The idea of PF, as I understand it, is to avoid the stuff that is not actually within the scientific community, and focus on the questions, discoveries, and hypotheses that ARE being pursued within the scientific community. This is because the primary goal here is education, not synthesis or research. Since there is such an enormous volume of available material which purports to be credible scientific discussion, but for which a significant fraction is not actually well grounded in anything being done within the working scientific community, it helps to have a guideline like this. If an idea is controversial, let's be sure that it really is within the intended scope of the forum -- discussion of the ideas that are being pursued within the working scientific community. (However, we do have the Independent Research subforum, where we CAN consider novel proposals beyond what is already being pursued in the scientific community.) Given that the discussion paper is controversial; my understanding of the guidelines is that it would be better to use as a source something that is from the scientific literature. That is, a peer reviewed journal or equivalent. If I have misunderstood the guideline, it is not deliberate. The guideline IS actually phrased as a restriction, however you want to understand it, so charging that I want to restrict debate is true enough. But I am not deliberately trying to distort the guideline to just to avoid ideas I don't share. I am in good faith wanting to work with the guideline as intended by Greg and the physicsforum staff. I think it is a good idea to have a forum like this with a goal of education and a focus on conventional working science. This gives ample scope to consider a very wide range of ideas; the scientific literature is full of open questions and disagreements and alternative ideas. New ideas are cropping up all the time. Felicitations -- sylas PS. I'd really like Monique in particular to comment here, as I have used her rulings in the forum to get an idea for what is intended and what is not. But any other authoritative PF voice would be very welcome. |
| Nov13-09, 06:32 AM | #19 |
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Do note that there is no new theory here. Again the report concludes:
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| Nov13-09, 08:00 AM | #20 |
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References I have given do say that the anomalous retreat of Himalayan and other glaciers is primarily driven by global warming; ergo, the counter claim that they are premature in this is controversial. Of course, in science any statement is technically provisional on new information; nothing is ever absolutely final and proven beyond question. Be that as it may, scientists do get to a point of making statements, when they have a good level of support. In msg #15, I have given references that DO make the statement that "glaciers in the Himalayas are retreating abnormally because of global warming", or else something more or less equivalent.
I absolutely understand that science depends upon debate and discussion and scope for disagreement with statements made by other scientists. I have no problem with that. I am just saying that, in line with PF's stated goal of education, that I would prefer to see the debate and discussion as it is proceeding within the working scientific community. My understanding is that it is not premature to identify Himalayan glacial retreat as exceptional, and directly linked with global warming. I base that not on my own independent research, but on my reading of the literature -- and I have given the references in support of that. Raina, apparently, disagrees. He has a right to his opinion, of course, and I am aware that he has good credentials as a scientist in his own right. But I am still not persuaded that his disagreement is well founded; it seems to fly against what I see in frankly more credible publications; and his reasoning seems flawed even to my own reading. The link from global warming to glacial retreat is controversial in the public sphere -- many people are skeptical of anything being linked to global warming. It is controversial in the political sphere; governments and politicians often have strong feelings about any statement that might have policy implications. Unfortunately, there are individuals -- on all sides -- who let policy distort their perspective on the credibility of various scientific hypotheses or statements. I honestly do not know about Raina himself. I've looked over his discussion paper and it seems rather flawed to me. I've refrained from pointing specifically at what looks dubious, for the time being. But -- for one example that struck me at the time -- it makes some quite startling claims without any adequate referencing. See the unattributed quote to unnamed scientists in the conclusion, page 54, for the notion that "a small mountain glacier would take 100 to 1,000 years to respond" to warming today. The same quote proposes that an explanation for observed retreat in the present is "they are responding to natural warming that occurred either during the Medieval Warm Period in the 11th century or to an even warmer period that occurred 6,000 years ago". There's no reference, no source, no name; it's just some unidentified scientists allegedly saying this; and it seems to be intended as a conclusion of the paper that this possibility makes it premature to identify current warming as driving the retreat -- in line with the statement you quoted. This is the kind of thing which I meant as "absurd", in my initial post of the thread. I can go into the reasons for this (specifically, the observed acceleration of retreat in the present) but that kind of thing really raises a red flag for me. My understanding of the Earth science guideline is that we should be primarily focused on learning about the prevailing practice of working science. Disagreements and alternatives included, of course! I suspect that the claims of this discussion paper, including the extract you quote above, are not actually well aligned with the disagreements and disputes that are carried on within the mainstream of active working science. I could be wrong about that, of course; and I could be shown incorrect with a more credible reference making the same assertions. Cheers -- sylas |
| Nov13-09, 05:06 PM | #21 |
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The conclusion does not rule out anything, hence it is not about firm facts. It just cautions that it sees too many caveats to make a firm claim yet. It would have been a claim, I think, if the word 'premature' was replaced by any synonym of 'wrong'. |
| Nov13-09, 05:11 PM | #22 |
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I think the onlty thing that is controversial in this thread is how to spell controvertial.
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| Nov13-09, 05:33 PM | #23 |
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I will try to find this.
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| Nov13-09, 06:58 PM | #24 |
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The news of this new research came out back in May. See, for example, Some Himalayan Glaciers Growing at Discovery News on May 5. The paper itself is most likely
I don't understand why the news reports mentions Everest. It may be a mistake. Everest is over a thousand kilometers from K2 and Nanga Parbat. The other two are way over the western Himalaya, which is described as the location of the research; Everest is not in the same region at all, and the glaciers there are actually in retreat. This all is building on the work cited previously, and drawing similar conclusions and revealing more detail. The Western Himalaya stands out as an exception to the usual global trend, and glaciers there are growing. This has been known for some time, and it appears for example in the IPCC reports. The paper I cited previously in msg #15 by Fowler et. at. (2006) is specifically on this point. Here's the older paper:
Professor Shroder is very active in investigations of the Western Himalaya. Unfortunately, I think that a number of blogs and dubious sources like the Heartland institute are still passing around the old news reports from earlier in the year, or derivatives thereof, and missing the point. This is why I always try to go back to the original source; as I appreciate you have tried to do as well. As a matter of chasing up a case of confusion in reporting, I am particularly interested in that mention of Everest. It does show up in the Discovery News report, which is the earliest I can find, and I suspect this may be where the confusion was introduced. It has been passed on in some cases as saying that the glaciers in Everest are advancing, which is incorrect and not actually a statement in the Discovery News report or the paper. I will email Professor Shroder and ask. Cheers -- sylas |
| Nov13-09, 07:35 PM | #25 |
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Breaking news! This discussion has now appeared in Science magazine, which is certainly a credible resource, and the report quotes a number of working scientists -- including Professor Shroder -- who express a range of views. The report is not itself a journal article, but rather a news coverage of some of the reactions, which are by no means uniform.
See:
I have sent the email to Professor Shroder, and I will let you all know of any reply. Cheers -- sylas |
| Nov13-09, 07:40 PM | #26 |
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This is from April 2009, |
| Nov13-09, 08:29 PM | #27 |
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The paper is in the 50(52) issue, and Jack Shroder has no other paper listed in the 2009 issues of this journal. The full reference given for the paper is: Glacier velocities across the central Karakoram Authors: Copland, Luke; Pope, Sierra; Bishop, Michael P.; Shroder, John F.; Clendon, Penelope; Bush, Andrew; Kamp, Ulrich; Seong, Yeong Bae; Owen, Lewis A. Source: Annals of Glaciology, Volume 50, Number 52, October 2009 , pp. 41-49(9) Publisher: International Glaciological Society Cheers -- sylas PS. For the record, the email I sent to Professor Shroder is as follows: Dear Professor Shroder, |
| Nov14-09, 04:12 AM | #28 |
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So it seems that the reference to a forthcoming paper in the Discovery News article is most likely a reference to Copland et al, which came out 5 months later; and that there will be more to come. Cheers -- sylas |
| Nov14-09, 07:19 AM | #29 |
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By some estimates there are 15,000 glaciers in the Himalayans. These glaciers exists at different elevations and locations and receive varying amounts of precipitation. Some of the glaciers are colder and dryer while others are warmer and wetter.
Global warming involves not only warming temperatures, but generally rising precipitation levels. If a glacier exist because it is in a particularly cold and dry location of the Himalayans, then it could easily grow while it warmed if it also received greater precipitation. So, there is no physical reason why all glaciers must retreat due to global warming. The Himalayans are extremely high elevation. There are hundreds of mountains over 8,000 meters high; elevations that are very cold. |
| Nov14-09, 07:41 AM | #30 |
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The paper cited previously, by Fowler et al (2006), indicates that in the western Himalaya, summer maximum temperatures are actually falling slightly, and that winter precipitation is increasing. This is proposed as a major reason for the difference in the response in the western Himalaya to the rest of the region. Cheers -- sylas |
| Nov14-09, 09:24 AM | #31 |
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| Nov14-09, 09:33 AM | #32 |
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| Nov14-09, 09:54 AM | #33 |
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Well there is little doubt that somebody is going to claim that glacier growth is caused by global warming as it happened some 9000 years ago.
abstract here |
| Nov14-09, 05:57 PM | #34 |
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Is anyone seriously doubting that there can be major regional differences in response to globally changing temperatures? Either now or in the past? And given this, is there anyone actually disputing that some glaciers may be advancing in the present due to changes arising in the present global warming episode? NONE of the sources cited in this thread -- including the discussion paper, or the papers on the western Himalaya by Fowler and Archer, and by Shroder's group -- is disputing the observation that there is a significant worldwide trend of retreat in glaciers. They are looking at exceptions to the trend. Inferences and hypothesis about dynamics will also differ between scientists. Research on these anomalous glaciers that are advancing is critically useful for understanding better the complexities of glacier dynamics and their interaction with climate. The links Andre is giving are to a recent publication and to an associated news report which is relevant to this whole discussion.
Glaciers are in a continuous state of change, and respond to changes in climate in sometimes quite complicated ways. There can be time delays in response; there are responses to temperature and to precipitation, and sudden surges or moves as melt water lubricates the base of a glacier and changes how much friction there is for movement. The paper is mostly on changes 6000 years ago, with some comparison also to 9000 years ago. The reference of the newspaper story title is about a few anomalous glaciers in central Asia which did advance in the early Holocene when global temperatures were increasing and most glaciers were retreating. .. Although there is evidence for large pre-LGM and LGM advances in the southern Himalayas and Tibet (eastern zone), evidence for a large early Holocene (∼9 ka) advance distinguishes it from the rest of Central Asia...In the modern era, there are all kinds of quite drastic changes going on. Scientists investigating changes in glaciers can benefit from studying also the changes that have occurred in the past. An extract from the news report explains this plainly:-- Rupper et al (2009) p338 The story of these seemingly anomalous glaciers underscores the important distinction between the terms “climate change” and “global warming.”Global change and regional change This paper is particularly relevant to the point which is being made in the previous references: that there are strong regional differences in a time of globally changing climate. The previous papers in this thread have explained and measured such differences. For example, from the abstract of Fowler and Archer (2006) (see msg #15): The observed downward trend in summer temperature and runoff is consistent with the observed thickening and expansion of Karakoram glaciers, in contrast to widespread decay and retreat in the eastern Himalayas. This suggests that the western Himalayas are showing a different response to global warming than other parts of the globe.The Earth periodically experiences times of strong global change, such as the start of the Holocene some 9000 years ago, or the current global warming trend. This research is helping to explore the changes at such times in more detail, and particularly to consider differences in different regions. To help it read more easily as a summary, I have removed the references. Here are the opening paragraphs of Rupper et al (2009):-- Fowler et al (2006), abstract In modern climate dynamics a central concept is that climate variability tends to be expressed in spatial patterns on a regional scale. Well-known examples of this are the El Nino-Southern Oscillation, the Pacific Decadal Oscillation, and the Arctic Oscillation. In past climates too, there are strong indications that climate changes occur in patterns, and no reason to suspect that they do not. Proper characterization and interpretation of past climate variability therefore requires a dense network of paleoclimate proxy records.And from the conclusion: The consistency between all GCMs reinforces confidence that the model results are a robust response of the climate to the changes in insolation forcing. In the case for Central Asia, spatial patterns in climate occur in response to a relatively uniform increase in solar insolation at the top of the atmosphere. The patterns in glacier advances across Central Asia are a result of the spatial variability in the climate response. This suggests that spatial patterns in climate and glaciers should be expected even in cases where there is a uniform change in forcing (e.g., increasing CO2).Summer Rupper has also been in the news recently, for a letter to Utah legislators on policy responses to climate change issues.-- Rupper et al (2009) p345 "We have no specific political agenda to support but agree that whatever action is taken, it should be informed by the best available scientific evidence," the scientists said. "We encourage our legislators not to manipulate the scientific evidence to suit any political agenda."The letter that was sent is here: Open letter to the Utah Public Utilities and Technology Interim Committee, Governor, U.S. Senators and Congressmen. Cheers -- sylas |
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