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Global warming and glaciers melting

  1. Jul 7, 2005 #1
    Global warming and "glaciers melting"

    In another thread I promised to go over all the alarming climate features like glaciers melting, sea levels rising etc, I think that was actually off topic over there so I start a fresh one.

    About the glaciers and ice sheets; yes, most glaciers are receding currently as the press can’t stop pointing out continuously. Is this catastrophic and/or alarming?

    Some glaciers are advancing though. It’s about a 70-30 ratio. Glacial behavior in the current epoch of the Holocene (as of 10,000 14C BP or 11,600 Cal BP) has been scrutinized. Just for checking a few refs out of several dozens:

    Douglass D.C. et al (2005) Evidence of early Holocene glacial advances on southern South America from cosmogenic surface-exposure dating, Geology March 2005 p.p. 237-240.

    Mayewski et al (2004) Holocene climate variability Quaternary Research V62 p243-255

    Porter (2000) The onset of Neoglaciation in the Southern Hemisphere, Journal of Quaternary Science v. 15 p395-408

    Despite the general idea that the Holocene was a general warm period, those refs show that there was a considerable variation in glacial developments on a global scale. Distinct mostly global glacial growing eras have been identified from significant moraine remains that have been dated from ~8800-8000 BP, 6000-5200 BP, 5200-4800 BP, 4200-3400BP, 1400-1100BP (600-900AD) and 400-100BP (1600-1900AD). The last period is well known as the Little Ice Age, despite the attempts to kill it (MBH99). Glaciers have receded considerably after all those periods. Crops were growing on Southern Greenland around 1000 AD, the reason why this now almost fully glaciated island got its name ‘Greenland’ in the first place. No wonder that this period was called the “Medieval Warming Period”.

    So what do we see now? Just another deglaciation event on a global scale after just another one of those periods of massive glacial advances, that Little Ice Age. But that’s not what the 3th Assessment report of IPCC likes to tell us. So you have to do with the selective information that the ice sheets and glaciers are melting. Full stop. Considering though, that it happens all the time, I fail to see neither a reason for an anthropogenic cause nor any alarming catastrophe ahead.
     
    Last edited: Jul 7, 2005
  2. jcsd
  3. Jul 7, 2005 #2
    Anyway, if the BBC is doubting global warming, then the hype must be over soon:

    http://news.bbc.co.uk/1/hi/sci/tech/4636115.stm

     
  4. Jul 8, 2005 #3
    Thank you for taking the time on that. Please excuse typos, I am typing with a sick child sitting on my lap. I also don't hold much hope that this discussion will go anywhere. Still - maybe it will.

    One reason there is broad consensus that climate change is happening in part because of human activity, is because there are so *many* independent factors that all point in the same general direction. I can reiterate those if you like.

    There are multiple questions.

    1/Is the planet warming?
    2/Does warming occur naturally?
    3/Is human activity contributing to the present cycle?
    4/Are we likely to have a runaway greenhouse?
    5/Should we try to "fix" the "problem" How?
    6/What is the evidence for any particular position?

    I think we agree that the answers to one and two are "yes." Yes? The planet is warming, and warming cycles occur naturally. If we agree on these, then any warming period in the past - doesn't really pertain to what is going on presently. In other words, saying that the ice sheets melted in the medieval warm period, becomes a red herring. Because the concern among scientists isn't that the planet has cycles --- THe concern is that the present warming is unusual! It's important to understand that there are cycles, because then you can ask whether the present change is wholly natural.

    Yes, the ice sheets have melted in the past. Yes, some are advancing. But as I mentioned before, this is one reason that "Global Warming" has been re-termed "Global Climate change. It's not all about warming, and the focus is on whether what is happening today is unique from what has happened in the past. There are unique factors in the world today that are likely to play into climate change (This is common sense as well as scientifically validated): These factors include industrialization, (rising ppm CO2) deforestation, hottest years on record in the last few decades, and so on.

    But it's not all about warming, it's about climate *change.* I am sure the Europeans and British here, are aware that predictions are for Europe to cool, not warm, because of changes in ocean currents. So to sum up this section -- I am unclear as to how your response in any way argues against CO2-driven climate change in our present day. I believe you are simply saying "We've been warm in the past, and some glaciers aren't melting anyway." ??? I agree. How is this pertinent?

    In addition to agreeing on the answers to questions 1 and 2, I think you and I also agree that 4 and 5 can't be answered at present, there are too many unknowns.

    3 seems to be where we get hung up. Considering the amount of deforestation (loss of carbon fixers), the amount of burning that we do (and manufacturing, and so on, the sheer mass of hydrocarbons that are oxidised to make our lifestyle possible), the understood chemistry of how resulting CO2 can act as a GG, ... we end up agreeing that the climate model is sensible (certainly not unsensible) and quibbling over whether we should do anything or not -

    We are smart enough to make a better planet for ourselves. Is it necessary? Well, we've got nowhere to go if we blow it here. Caution seems reasonable.

    The BBC report in your second post here, adds weight to what has already been considered in the models.

    In other words... So? What's your point with the BBC article?

    Do you have additional feedback on the other "slippery slopes" that I mentioned? Decreasing pH in the oceans, rising sea level, and other items?
     
    Last edited: Jul 8, 2005
  5. Jul 8, 2005 #4
  6. Jul 8, 2005 #5
    Quick reply, all the best with the little child.

    First the article, Since the BBC has really mounted a heavy charge on enforcing the global warming ghost, it's really a surprise to see some rational talking. That's it.

    Meaning? Objective: we will not find the physical mechanisms that drive climate? or you can’t convince me of the impending catastrophe? BTW It’s rather impossible to reconvert an old believer who found out that he has been conned.

    As in anthropogenic CO2 production?

    And how much would that contribution be? 0,01%, 1% or 75% or whatever? Suppose I proof that greenhouse gas is cooling instead of warming. Consider this. CO2 molecules have the correct eigen frequency to absorb a certain bandwidth of IR light and heat up in the process and heat up the atmosphere in turn. Physical properties make this process reversible. CO2 can emit photons at the same frequency and cool in the process, thus cooling the atmosphere around it. So CO2 cools

    Then how can the world have apparent 33 degrees C greenhouse gas effect? This could simply be a hysteresis effect. Earth heating up mostly at the equator, the Hadley cell mechanism transports the heat towards the poles, cooling the equator area, so the daily cycle will be affected by cooling less due to less difference. With a little imagination you can see in the Hadley cell and the day-night cycle a pumping mechanism that fills the atmosphere with heat as a capacitor without any help of greenhouse gasses.

    That would explain why the Earth has managed to maintain living conditions throughout its history, despite enormous variations in CO2 levels like perhaps ~15 times the present level some 400 million years ago.

    But it’s better to keep the posts shorter, so I stop here. The remainder will be addressed, you bet. #4 is the big question of course.
     
  7. Jul 9, 2005 #6
    Of course, the little idea of greenhouse gas absorption and emission of photons causes some resistance for the IR energy to leave the Earth again. That resistance causes a potential difference analogue to electric circuits and that's the real greenhouse gas effect. But the Hadley cell heat transport part may very well be much more important for the reason why the Earth is about 33 degrees warmer than the solar isolation would suggest.

    Now
    No, we can. There has never been such a thing as a runaway greenhouse. So what makes us think that it would happen now?

    Now you may wonder if this statement is the result of incredible ignorance or the conclusion after scrutinizing Planet Venus, The Dansgaard Oeschger interstadials and the Younger Dryas.

    Perhaps walk around a little bit here, especially this. and perhaps we can discuss some of the misconceptions here.
     
    Last edited: Jul 9, 2005
  8. Jul 11, 2005 #7
    I seem to observe that a promising discussion has stalled here. Probably because I made such outrageous claims, about no precedence of catastrophic runaway greenhouse effects. Yet, I linked to a mega site that scrutinises how the global warming was discovered, mostly in the ice cores of Greenland that showed astonishing temperature jumps in the past “ice ages”.

    “10 degrees within a decade” the typical slogan that triggered Schneider, Hanssen, Alley et al into sounding red alert about catastrophic climate changes. This is the sole and direct reason for the global warming hype.

    However the conflicting interprations of ice age evidence proved far too obstinate to be solved (completely?):

    But if we can’t explain the ice ages, have we interpreted the evidence correctly? And if we haven’t, why do we think that we know everything about the temperature changes in the past ice ages?

    And indeed, the idea about catastrophic cooling and warming is basically undisputed. These were supposedly related/caused by CO2 levels. However, when the ice age evidence was not clear enough about the latter, the hockeystick was invented to replace it, having played it brain-paralysing role very well. Even now, when some of us slowly start to accept that the hockeystick has been falsified, we still cannot abandon its overwhelming global warming notion.

    Now about the ice ages. Have a look at this conflict again (I have posted it somewhere else before). It's about the same place (Greenland) and the same time (Younger Dryas) but not the same temperatures:

    http://www.ncdc.noaa.gov/paleo/pubs/alley2000/alley2000.html
    and http://www.geol.lu.se/personal/seb/Geology.pdf.pdf

    So the questions are obvious. Who is wrong here and why? What happened? But the most important: if we proof that “10 degrees within a decade” is a fairy tale, will that be able to stop the global warming hype?
     
    Last edited: Jul 11, 2005
  9. Jul 11, 2005 #8
    One more thing. If "brain paralyser" for the hockeystick sounds a bit overdone and offensive, perhaps check out what pure sang climate scientist Hans Von Storch has to say about this.

    The abstract of his presentation at Boulder the other day and the Power point presentation (26mb!!)
     
  10. Jul 13, 2005 #9
    Sorry Andre but I don't see that the suggestion about the functioning of atmosphere without the greenhouse effect can work.

    "Consider this. CO2 molecules... ...So CO2 cools"

    But you are ommitting the rest of the atmosphere from the energy balance in this and CO2 is only a small percentage of the gasses in the atmosphere. Thus the photons that CO2 emits in the infra red region do cause a warming to the region of atmposphere in which they are emmitted. i.e. the greenhouse effects.

    "Then how can the world have apparent 33 degrees C greenhouse gas effect? Earth heating up mostly at the equator, the Hadley cell mechanism transports the heat towards the poles, cooling the equator area, so the daily cycle will be affected by cooling less due to less difference. With a little imagination you can see in the Hadley cell and the day-night cycle a pumping mechanism that fills the atmosphere with heat as a capacitor without any help of greenhouse gasses."

    Once again this hadley cell theory doesn't work. Without the greenhouse effect causing the retention of heat, the diurnal variation of temperature from solar radiation would be far more apparent, i.e. without the greenhouse effect why does the temperature not drop further at night than observed, even without cloud cover.

    Furthermore is it really feasible that such an obvious solution to the issue of heat transport has been overlooked. Lovelock's Gaia hypothesis is interesting on the long-term relative stability of climate.

    Or am I taking you too much at face value here? ;)
     
  11. Jul 13, 2005 #10
    Interesting, I'm not sure that we are talking as closely along each other as possible (definition of communication). Let's try again.

    I think that greenhouse gas effect physical reversible. CO2 takes up photons and heat up (kinetic energy) but as it retransmits these photons again, it cools, loosing the kinetic energy, No?

    The net effect is resistance for a photon that is transmitted from the Earth Surface back to space. It will be intercepted a few times and then released again, obstructing the direct path to space. Resistance causes a potential gradient like in an electrical circuit and the voltage drop on a resistor is comparable to greenhouse effect of CO2. But wherever there is more photon emission than absorption, there must be cooling. This happens probably in the stratosphere.

    Now, is there any other delay/resistance mechanism playing? I do think so. Declaring the Hadley cell construction not valid is easy, but when there is a reasoning behind it, it would be also prudent to unreasoning that. It’s called refuting.

    Anyway, a large part of the solar heating is causing water evaporation. Water vapour is probably the biggest “heat sink” taking up how many joules per kilogram? It was a lot, I seem to remember. Condensation releases that heat again, heating up the local air molecules. The non-greenhouse gas molecules do not play the photon game and don’t loose that heat again by reradiation, so the air stays warmer.

    The Hadley cell mechanism is a big conveyor belt, sending gigatonnes of water vapor and consequently heat into the air, and again the air is actually warmed it during condensation and as said that warming is retained much better, due to the lack of reradiation. So a considerable greenhouse gas effect without greenhouse gas, just physical transport of heat. Compare it to the heat at the backside of the fridge. Same process.

    Now refuting this process would need to point out where this reasoning is wrong.

    Disclaimer: I have not invented this for once. Somebody else did, we just discussed it.
     
  12. Jul 13, 2005 #11
    It is true that the emmission of a photon causes the CO2 molecule to lose energy or 'cool'. In fact this is also true of any greenhouse gas, such as water vapour. However in a given area it is not the cooling upon emission, warming upon absorption for an indivual molecule that is crucial, but the overall energy balance in the area.

    The crucial thing here is not the emmission/ absorption in itself, but the spectral characteristics. Water and CO2 absorb UV and emit IR band radiation. It is the coverage of Water vapour spectral absorption gaps by absorption modes in CO2 that allows the CO2 to create a net increase in IR emission, and thus heat.

    Disproving the Hadley Cell idea would, I suspect require, simulation. And I'm not set up to do that. There may be a kickself obvious reason but it eludes me right now. However consider this: The spectral emmission absorption charcteristicsn I outline above are not negligable because they increase the overall energy budget input for a given area. Thus the planet must radiate more energy into space to reach a new equilibrium state. It does this by 'raising the temperature'.

    Convection plays it's part but ignoring these fundamentals of thermal physics would not, it seems to me, indicate that the model is complete.
     
  13. Jul 13, 2005 #12
    Oh and by the way, above you posted 07-11-2005 at 10:26 AM.

    "But if we can’t explain the ice ages, have we interpreted the evidence correctly? And if we haven’t, why do we think that we know everything about the temperature changes in the past ice ages? " You preceded this with a quote from another source.

    Again I must disagree, I posted some more detail about this on BBCi Weather/environment board, http://www.bbc.co.uk/cgi-perl/h2/h2.cgi?state=threads&board=weather.environment&sort=T&offset=25

    We can explain the ice ages, in quite good broad detail. And CO2 drvien greenhouse warming was not a factor in them. Indeed in the Law Ice Dome and Vostok proxy data the CO2 lags the temperature as a result of biological processes responding to the changes in received solar energy and their subsequent amplification by factors such as ice albedo. These CO2 changes may have exacerbated the initial changes in temperature, but they were not the cause.

    Expecting us to be able to go back 100,000 years ago and explain every single aspect is asking too much. But there is good agreement. The post I link to above is factually correct, the details do not detract from that. Nor do they detract from the fact that Milankovitch cycles or a ‘re-bound’ from the Little Ice Age (which was actually due to solar activity – Maunder Minimum), are not responsible for the current observed warming.
     
  14. Jul 13, 2005 #13
    Please do and make my day :biggrin:

    and I tell you it's the biggest slippery slope in scientific history. Nothing is what it looks like. The 100,000 eccentricity cycle that you mention in other thread slipped in after the discovery of the 100ky cycle in the proxies. But it's not very accurate since before that, the main eccentricity cycle was 410 Ky with a very weak 90 Ky component. But why why why would that 100 Ky cycle only jump in after some 950 Kya out of the blue, being non existed before. Muller tried with his inclination cycle and the dust band but failed.
     
  15. Jul 13, 2005 #14
    Oh and it may be a good idea to read the Mammoth murderer thread to have an idea about the opposition. After all, That's the scientific method, no? Observe first.
     
  16. Jul 13, 2005 #15
    "Please do and make my day" See the post I referred you to at BBCi, a broad account of the Milankovitch (M) cycles.

    This still does not affect what I am saying.

    If the past climate changes were due to M cycles or solar variance then we'd be able to see a change in solar radiation that correlates with the recently observed warming. But we don't. The M cycle effects on solar radiation are FAR to slow to account for the MSU and surface temperature trends. There is no evidence of a correlatory change in solar irradiance. If Solar radiation had as great an effect as for example Vizier argued, then we'd see an 11 year climatic periodicity, we don't.

    As I said in an earlier reply on the previous thread. I have no interest in being sidelined into a discussion of the vaguaries of paleo-climatology. What interests me is a valid alternate hypothesis to the theory of Anthropogenic Climate Change due to CO2 emissions.

    So when I say it's understood "quite good broad detail" I mean (should have made this more clear, sorry!) that we can be fairly certain that none of the factors that could give reasonable explanations for past change apply now. That's my benchmark for "quite good broad detail".

    We may be arguing at cross purposes here, it's just that when I've read your comments about 'global warming hype' I thought you had some alternate explanation aside from anthro-CO2 emmissions. And having been quite sceptical about the theory of CO2 causing climate change in the past myself, I'm interested in such theories.

    The problem is none of the ones I used to think were OK work, that is once I've actually looked into them so I'm forced to accept that the increasing evidence of climate change, such as the pattern of glacial retreat in temperate and equatorial lattitudes does clearly support the theory of CO2 initiated warming. i.e. the planet is warming and it's virtually totally due to the additional forcing of CO2.

    Got to pop off now, will reply to any posts tomorrow.
     
  17. Jul 13, 2005 #16
    That's a most accurate describtion of the major main problem of science: "have no interest". If you're really want to know what's going on you must be interested in everything and a bit more. There are no islands in science. Everything is interconnected but "no interest" means no solution because that solution just happens to be in an adjacent speciliased area. Now, if you really take a few minutes and read that thread it may be a bit more clear what is going on.

    About the accuracy of Milankovitch, you are aware of this publication (Karner & Muller, Science 2000) of course.
     
  18. Jul 13, 2005 #17
    I haven't visited this forum in a few days, Andre. My focus has been wrenched to the political events of the past week.

    Also, I find your general approach to the discussion, counter-productive to any further understanding on my part. You appear to be attempting to drown your opposition in virtual reams of (questionable) data. To the extent that I have looked into such sorts of sites in the past, I have not been impressed. And I have little interest in "debating" in this manner.

    If anything I offer is countered by a: Go "here" and do your homework and then maybe you'll understand why the scientific community is wrong, and you are too by the way, rather than a legitimate back - and - forth exchange, then I fail to see why you think I should be interested in what you have to say at all. In other words, you do not acknowledge the science I mention, so why should I bother with yours?

    This approach of yours may also explain why these topics do not engage a significant proportion of the PF community.
     
  19. Jul 13, 2005 #18
    I see, heads, you win, tails, I loose, right? Yes I do attempt to prove why things are a wee bit different than IPCC et al assume, which is terribly complicated, but if I attempt to explain, I lose the attention.

    Do you really think that the moderators here allow me to terrorrise this forum? Check their activities elsewhere. I'm very happy that the scientific method prevails here. If you can stubstantiate your ideas with sound physics, scholar- and/or peer reviewed publications then it's called science and it's allowed here. That's what I try do all the time. And if you think that the community is not engaged then just tick off the number of hits that my threads are getting.

    But what are you interested in? What happened in the past and what this is learning us for the future or global warming to prevail?

    Please explain questionable data.
     
  20. Jul 13, 2005 #19
    Apparently you don't see, no.

    I am saying that your approach is confrontational, and this does not hold my interest. I am not flipping a coin. I simply do not see communication occuring here. Communication needs to start with common ground. This is why I tried to start my earlier contribution on this thread with the answers to questions that you and I agree on.

    I expect they simply recognize that you are largely ignored. You're really not hurting anyone here. You're not flaming anyone, and you're hardly "terrorising" anyone.

    Ummm... small point. What you've described is not "the scientific method." THe scientific method is a procedure that involves about 5 - 7 repeated steps including experimentation. What you have described, is debating techniques. I would fully expect that the moderators allow your debating techniques - there's nothing wrong with them! And besides, you are evidently largely ignored. :rofl: (sorry, I get childish sometimes.)

    I hadn't thought to follow that. Thanks for the tip. How do I assess what people are thinking when they read your threads? And how does read equate to "engaged?"

    OK - so I took a minute and looked. I'm impressed Andre! On any UBB forum I have ever checked, the ratio of replies to reads is around 1:10. Yet, on your threads, the ratio is consistently less - about 1:15. And many of those replies are your own contributions. Explain to me: how exactly this argues that PF participants are engaged?

    Let's do another experiment. Let's see how many reads you get --- for any length of time that a thread has been view-able. I'll check two of your threads from "earth":

    "The hockey slapstick" was posted on 5-14 (two months ago) and has had 342 views.

    "Glaciers melting" was posted on 7-7 and has had 248 views.

    Now, on Biology (a forum that should have roughly equal interest) "Three legged body plan" was posted on 7-8 (last friday) and has had 317 views.

    "Neurotransmitters" was posted on 7-11 (two *days* ago) and has had 138 views.

    You're right - this type of data does say something about how engaged the community is.

    My interests are more broad. I am interested in how we are negatively impacting the planet in any number of ways. Climate change is just one area - Deforestation, pollution, habitat loss, and other areas are causing the greatest mass extinction in very, very long time. We should be proud - we appear to be as devastating to this planet as any past extinction event.

    I am further interested (in a more general way) in educating others (and being educated myself) to inform themselves, and to think about these issues critically. Something I haven't done as yet, here.

    What I am not interested in, is investing inordinate amounts of time in anyone who has no interest in discussing a viewpoint outside their own. Note: I am not saying that such a person has to change their mind. What I am saying is that there are people on the internet with whom discussion appears fruitless. I'm not saying you are such a person, but you certainly have rung off a few warning bells in my head.

    I believe I said questionable sites. An example is: A website that claims to be devoted to determining good policy, but only links articles that argue one side of an issue. Such as the site that Dennis who-sis-face is on, on the other thread I commented on today. (I may have said questionable data on this thread - but the same sort of issue would apply. Data that is used out of context; data that is funded by Exxon, data that is not properly controlled ---- there are things like these in almost any piece of anti-warming literature.)

    Yes, my tone is confrontational - And this is in direct response to your general approach. I used to back off when people became confrontational. But what I have learned is that this response, leaves potentially fertile forums dominated by a few opinionated individuals.

    When I have time later I'll take a more pro-active approach to injecting some threads (Not necessarily climate change) that hopefully will provide a little more balance to this area of the PF boards.
     
    Last edited: Jul 13, 2005
  21. Jul 13, 2005 #20
    I'm sorry, Andre. Some of that was unduly harsh.
     
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