Global warming and glaciers melting

In summary: CO2 levels, deforestation, etc.), the IPCC has identified human activity (burning fossil fuels, etc.) as a major contributor to the present warming. So, the evidence is there, and it is conclusive. So, yes, global warming is happening, it's been happening for a while, and it's likely caused by human activity. The evidence is overwhelming, and there is no way to "fix" the problem. We need to keep burning fossil fuels to keep the planet from getting too cold.
  • #1
Andre
4,311
74
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:
Earth sciences news on Phys.org
  • #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

A stalagmite from an Alpine cave may indicate that global warming is not as unusual as many think...cont'd
 
  • #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.

...confirming a Medieval Warm Period between AD 800 and 1300.

The warm spell is also indicated in some studies of tree-rings, ice-cores and coral reef growth records.

Writing in Earth and Planetary Science Letters the researchers suggest that global warming is a natural process.

Other scientists, however, say phenomena such as the Medieval Warm Period become less significant when broad sets of so-called "proxy data" are calibrated and synthesised to give a truly global picture - not just regional ones.

When this is done, they argue, the warming witnessed in the past few decades appears to be very unnatural.

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:
  • #4
Another board mentioned the BBC article in this thread, if you are interested in additional discussion on it:

http://www.bbc.co.uk/cgi-perl/h2/h2.cgi?thread=%3C1120823038-3845.14%40forum1.thdo.bbc.co.uk%3E&find=%3C1120823038-3845.14%40forum1.thdo.bbc.co.uk%3E&board=today.3&sort=Te

Patty

p.s. you need to go halfway down the thread to find reference to the article.
 
Last edited by a moderator:
  • #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.

I also don't hold much hope that this discussion will go anywhere.

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.

3/Is human activity contributing to the present cycle?

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.
 
  • #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
4/Are we likely to have a runaway greenhouse?...
I think you and I also agree that 4 and 5 can't be answered at present, there are too many unknowns.

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 http://www.aip.org/history/climate/, especially http://www.aip.org/history/climate/cycles.htm and perhaps we can discuss some of the misconceptions here.
 
Last edited:
  • #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?):

“The sheer number of explanations for the 100,000-year cycle... seems to have dulled the scientific community into a semipermanent state of wariness about accepting any particular explanation." The grand puzzle of the ice ages stood unsolved — except insofar as scientists now understood that nobody would ever jump up with a neat single solution.

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:
  • #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 http://w3g.gkss.de/staff/storch/ABSTRACTS/050708.boulder.pdf
 
Last edited by a moderator:
  • #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? ;)
 
  • #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.
 
  • #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.
 
  • #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.
 
Last edited by a moderator:
  • #13
We can explain the ice ages, in quite good broad detail.

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.
 
  • #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.
 
  • #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.
 
  • #16
I have no interest in being sidelined into a discussion of the vaguaries of paleo-climatology.

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.
 
  • #17
Andre said:
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.

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.
 
  • #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.

This approach of yours may also explain why these topics do not engage a significant proportion of the PF community.

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.
 
  • #19
Andre said:
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.
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 occurring 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.

Do you really think that the moderators here allow me to terrorrise this forum?
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.

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.

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.)

And if you think that the community is not engaged then just tick off the number of hits that my threads are getting.

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.

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?

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.

Please explain questionable data.

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:
  • #20
I'm sorry, Andre. Some of that was unduly harsh.
 
  • #21
Accepted, I have spend some time to go over the older threads, trying to find out what is so wrong with my approach, other than being sceptic of global warming. I was tempted to start tackling the usual EXXON fallacies but that won't help much either.

This thread was supposed to be about glaciers growing and I intended to show their persistent abnormal reaction to temperature changes in the late Pleistocene and the Holocene but instead we are talking about my confrontational style with suspect data.

It may seem strange but my interest is finding the truth. Having studied a lot of paleo climatal issues I have concluded that anthropogenic global warming is not one of them. I'm more than happy to share why but that will be quite impossible this way.

There is little point continuing this. It's always possible to review my https://www.physicsforums.com/search.php?searchid=212206 . It has all been said before.
 
Last edited by a moderator:
  • #22
Your approach is... fine (I suppose), but I don't wish to engage with anyone who can only see what they see. If, for example, you were to be less dogmatic in your position (exemplified when you say things like: "They lied to us about the MWP therefore the entire warming argument fails") I expect we'd do better. But there appears to be no room for question in your understanding, at least from where I am sitting.

You're right - the thread has gone off topic. I responded to your implication that it was your *claims* that I had a problem with. It wasn't. I just wasn't popping in, and you misinterpreted it.

Back to the point of the thread - *That* was a red herring as well, in my limited understanding. You seem to have the approach, of saying:

"Look! There have been warming periods in the past, so don't worry about current warming." And, "Look, glaciers are growing, so don't worry about warming."

While failing to mention that 70% of glaciers are melting. Only 30% are growing. And that this is why it is called climate *change* these days.

And failing to mention that the MWP has been incorporated into some versions of some models and doesn't change the general trend of the predictions.

This sort of tactic makes me skeptical that it is the "truth" that you are really after.
 
  • #23
pattylou said:
While failing to mention that 70% of glaciers are melting. Only 30% are growing. And that this is why it is called climate *change* these days.

I would be interresting to see if there a corelation were the regions is warming and glacier melting and vice versa. This is based on the idea that some regions are cooling and some are warming.
 
Last edited:
  • #24
I read today, that the NAO (North Atlantic Oscillation) explains why northern hemisphere glaciers seem to be melting, in general, more quickly, than southern hemisphere glaciers. I'll try to find a reference.
 
  • #25
Two possible explanations for two areas that have advancing glaciers:

For the last two to three decades, far more records have been available than are shown in Figure 2.18. Many are documented at the World Glacier Monitoring Service in Zürich, Switzerland (e.g., IAHS (ICSI)/UNEP/UNESCO, 1998) The general picture is one of widespread retreat, notably in Alaska, Franz-Josef Land, Asia, the Alps, Indonesia and Africa, and tropical and sub-tropical regions of South America. In a few regions a considerable number of glaciers are currently advancing (e.g., Western Norway, New Zealand). In Norway this is very likely to be due to increases in precipitation owing to the positive phase of the North Atlantic Oscillation (Section 2.6),
Thus, in Norway, changes in the NAO is bringing more snowfall which is allowing the glaciers to advance (not the same as my recollection mentioned in the previous post).
...and in the Southern Alps of New Zealand and due to wetter conditions with little warming since about 1980.

The New Zealand data seems to back up the correlation you ask about, and is more in line with my recollection from I-forget-where earlier today.

Finally, indications in the European Alps that current glacier recession is reaching levels not seen for perhaps a few thousand years comes from the exposure of radiocarbon-dated ancient remains in high glacial saddles. Here there is no significant ice flow and melting is assumed to have taken place in situ for the first time in millennia (e.g., the finding of the 5,000-year-old Oetzal “ice man”).
The link below (from which I lifted the above quotes) includes additional information about variables affecting glaciers the world over. This is not the reference I recall, however, and I'll google a bit more.


http://www.grida.no/climate/ipcc_tar/wg1/064.htm
 
Last edited:
  • #26
pattylou said:
…While failing to mention that 70% of glaciers are melting. Only 30% are growing. And that this is why it is called climate *change* these days.

opening post:

andre said:
yes, most glaciers are receding currently (…) 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.

?

pattylou said:
And failing to mention that the MWP has been incorporated into some versions of some models and doesn't change the general trend of the predictions.

You continue with that model thinghy. What’s the problem with prediction models?

The only place of prediction models in the scientific method is in formulating predictions to test the robustness of a hypothesis. So far the models of the mid-nineties have predicted a warming of several tenths of degrees for 2005. In reality temperatures have never reached the 1998 peak again, so it seems way too early to trust models.

To underline that why not google with climate models fail.

The main reason of the problems is “garbage-in-garbage-out”. The “garbage” being the exaggeration of the CO2 forcing and non existing positive feedback whilst underestimating the negative feedback in the models, as I have linked earlier to Hans Erren and Olavi Kärner respectively.

And perhaps remember that the positive feedback myth is caused by misperceptions of the ice core proxies about the ice ages.

About correlation of warming and the glaciers growing and shrinking. It seems to be much more erratic. In the Andes and the Rockies several adjacent glaciers behave differently.
 
  • #27
Some more remarks about model from Crighton who thinks that
http://www.s8int.com/crichton.html

Some interesting thought about the decline of the scientific method.

...
To an outsider, the most significant innovation in the global warming controversy is the overt reliance that is being placed on models. Back in the days of nuclear winter, computer models were invoked to add weight to a conclusion: "These results are derived with the help of a computer model."

But now, large-scale computer models are seen as generating data in themselves. No longer are models judged by how well they reproduce data from the real world-increasingly, models provide the data.

As if they were themselves a reality. And indeed they are, when we are projecting forward. There can be no observational data about the year 2100. There are only model runs. This fascination with computer models is something I understand very well.

Richard Feynman called it a disease. I fear he is right. Because only if you spend a lot of time looking at a computer screen can you arrive at the complex point where the global warming debate now stands. Nobody believes a weather prediction twelve hours ahead. Now we're asked to believe a prediction that goes out 100 years into the future?

And make financial investments based on that prediction? Has everybody lost their minds?

Stepping back, I have to say the arrogance of the model-makers is breathtaking. There have been, in every century, scientists who say they know it all. Since climate may be a chaotic system-no one is sure-these predictions are inherently doubtful, to be polite. But more to the point, even if the models get the science spot-on, they can never get the sociology. To predict anything about the world a hundred years from now is simply absurd.

Look: If I was selling stock in a company that I told you would be profitable in 2100, would you buy it? Or would you think the idea was so crazy that it must be a scam?

Let's think back to people in 1900 in, say, New York. If they worried about people in 2000, what would they worry about? Probably: Where would people get enough horses? And what would they do about all the horse****?

Horse pollution was bad in 1900, think how much worse it would be a century later, with so many more people riding horses? But of course, within a few years, nobody rode horses except for sport.

And in 2000, France was getting 80% its power from an energy source that was unknown in 1900. Germany, Switzerland, Belgium and Japan were getting more than 30% from this source, unknown in 1900. Remember, people in 1900 didn't know what an atom was.

They didn't know its structure. They also didn't know what a radio was, or an airport, or a movie, or a television, or a computer, or a cell phone, or a jet, an antibiotic, a rocket, a satellite, an MRI, ICU, IUD, IBM, IRA, ERA, EEG, EPA, IRS, DOD, PCP, HTML, internet. interferon, instant replay, remote sensing, remote control, speed dialing, gene therapy, gene splicing, genes, spot welding, heat-seeking, bipolar, prozac, leotards, lap dancing, email, tape recorder, CDs, airbags, plastic explosive, plastic, robots, cars, liposuction, transduction, superconduction, dish antennas, step aerobics, smoothies, twelve-step, ultrasound, nylon, rayon, teflon, fiber optics, carpal tunnel, laser surgery, laparoscopy, corneal transplant, kidney transplant, AIDS. None of this would have meant anything to a person in the year 1900. They wouldn't know what you are talking about.

Now. You tell me you can predict the world of 2100. Tell me it's even worth thinking about. Our models just carry the present into the future. They're bound to be wrong. Everybody who gives a moment's thought knows it.

I remind you that in the lifetime of most scientists now living, we have already had an example of dire predictions set aside by new technology. I refer to the green revolution. In 1960, Paul Ehrlich said, "The battle to feed humanity is over. In the 1970s the world will undergo famines-hundreds of millions of people are going to starve to death."

Ten years later, he predicted four billion people would die during the 1980s, including 65 million Americans. The mass starvation that was predicted never occurred, and it now seems it isn't ever going to happen. Nor is the population explosion going to reach the numbers predicted even ten years ago.

In 1990, climate modelers anticipated a world population of 11 billion by 2100. Today, some people think the correct number will be 7 billion and falling. But nobody knows for sure. But it is impossible to ignore how closely the history of global warming fits on the previous template for nuclear winter...cont'd
 
  • #28
Oh - My bad. You did mention the ratios. Sorry.
 
  • #30
"That's a most accurate describtion of the major main problem of science: "have no interest"."

And that's a patent misprepsentation by selective quoting of what I am actually saying Andre. I stand by my position, past climate is of interest, but what is happening now is not directly relevant to the past unless the same mechanisms apply. And the current observed warming is due to human emissions of CO2, not due to the paleological events of the past.

Off for the weekend now, have a good one.
 
  • #31
If you are actually saying something else then what you are saying, then why say it in the first place?

So what is the role of paleoclimatology in the current global warming hype? I'm confused.

Anyway this thread also veers off. It was about glaciers. no? Perhaps start anorther on "modern science supersedes paleoclimatogic vagueries".
 
Last edited:
  • #32
If you are actually saying something else then what you are saying, then why say it in the first place?

I saw your earlier remark ("problem with science...have no interest.")as a misrepresentation as well. This is one of the "stylistic" methods in your debate that sets of warning bells for me. You said you don't know what's wrong with your presentation - this is an example.

"...have no interest in being sidelined" is clearly not the same as "have no interest."
 
  • #33
To both

I have no interest in being sidelined into a discussion of the vaguaries of paleo-climatology.

To me is a obvious sign of contempt, the quote in full. That tends to have influence on the tone, I have to admit. :uhh:

The origin of the global warming fear was in ice age paleo climatology in the mid twentieth century when only little data was available. The fear got onto raging levels :yuck: when MBH forced the -now falsified- paleo-climatologic hockeystick down our throats as main poster child of global warming. But now we don't need all that paleo-climatic fear anymore because we have the (biased) surface temperature record http://home.wanadoo.nl/bijkerk/ghcn-sat-son-trends.jpg .

Slight detail perhaps, the temp. rise has stabilized since the 1998 peak.

Anyway, I try to explain why some people do know why the global warming threat is slightly exaggerated, since we do know a lot more about paleo climate now. Orders of magnitudes, voiding the original claims. This would lead to the notion that there is no more proof in the past that CO2 is closely related to temperatures.

But we are not interested in being sidelined into a discussion of the vaguaries of paleo-climatology. To me that does not sound very open minded for a discussion in which all elements of global warming deserve to be discussed.

Then if I point to a few problems with the Milankovitch cycle ideas, it get’s little attention, I'm afraid. If you want to explain the global warming idea, it might be a good idea knowing http://www.aip.org/history/climate/ behind it. Then this might also have been http://www.aip.org/history/climate/cycles.htm:

The more precise the data got, the less precise seemed the match between Milankovitch and ice age cycles. Evidently when orbital effects served as a pacemaker, it was only by partially adjusting the timing of greater forces working through their own complex cycles. As one reviewer said, "The sheer number of explanations for the 100,000-year cycle... seems to have dulled the scientific community into a semipermanent state of wariness about accepting any particular explanation." The grand puzzle of the ice ages stood unsolved — except insofar as scientists now understood that nobody would ever jump up with a neat single solution.

I believe have linked here before in some recent thread and I have given a slight hint about those problems (make my day).

Now about the last sentence of that quote. I intend to falsify that sometimes (well on my way) and I do hope that this is not going to be considered to be sidelined into a discussion of the vaguaries of paleo-climatology.
 
Last edited by a moderator:
  • #34
CW:
I stand by my position, past climate is of interest, but what is happening now is not directly relevant to the past unless the same mechanisms apply.

Dear Cobbyworlds,

The key to the present lies in the past. By studying past climate, we can better understand what is happening with our current climate, and have some idea of what to expect in the future. I would say this is vital research.

And the current observed warming is due to human emissions of CO2, not due to the paleological events of the past.

Sorry Cobbyworlds, but the jury is still out on this one. This is one of the most hotly debated issues in science today.

The "Hockey Stick" which is the keystone of the AGW house of cards, is a flawed study, and has not yet been replicated. Scientific experiments have to be replicatable. Billions of taxpayers dollars in Kyoto taxes hang in the balance, and now the U.S. Congress is investigating Mann Bradley and Hughes work.

The House of Lords now opposes Kyoto
http://news.scotsman.com/politics.cfm?id=746502005

I have observed that those who are pro-AGW tend to be fanatical in their zealousness, and challenges to their views or studies are loudly and acerbicly decried. This is not the way science normally proceeds. There are those in the AGW camp who have deliberately misled the public so that they can represent their reports as having no caveats. One prominent scientist is reported to have said "We have to get rid of the Medieval Warming Period". If he could get it accepted that MWP was regional and not global, he could succeed.

And in an earlier presentation at the December meeting of the American Geophysical Union, Overpeck asserted the so-called Medieval Warm Period was local, not global. We’ll concentrate on that one here.

His bombshell concept is that the Medieval warming was so substantial that it allowed the Vikings to sail westward without freezing to death, colonizing Greenland and North America, but it was not created by a general planetary warming. This theory implies that the Little Ice Age, the cooling that later decolonized that area, was similarly nonglobal; otherwise the Warm Period would have shown up as, well, global warming, compared with succeeding centuries.

Overpeck’s speech prompted handsprings of joy from our greener friends. Now, instead of saying that the 1990s (and, in particular, 1998) are the warmest in 600 years (which goes back to the beginning of the putative Warm Period), they can say they’re the warmest in 1,200 years. "Obviously," they can remark, "the Warm Terror is here and we need to raise taxes pronto to stop the burning of fossil fuels."

Others might say, "Sure am glad I haven’t spent a lick on heating oil and it’s almost Christmas. Think I’ll go and buy some stuff for the missus."

Still others, somewhat more penurious and even-headed, realize that Overpeck has created the apocalyst’s biggest nightmare. If he’s right, then regional climate naturally varies tremendously, whether or not the globe warms. Climate changes so dramatic that they promoted Viking exploration are simply the way of things. And ditto for their flipside—large regional coolings such as the Little Ice Age, an event that sent the Rhone Glacier in the Alps some 5,000 feet farther downslope than it is today.
http://www.greeningEarth'society.org/Articles/logic.htm

If anyone has an issue with the quality or content of the site I linked to, don't take my word for it! Google on Overpeck and you can confirm the information for yourself.

Do you think a regional climate event would cause a Swiss glacier to grow by almost a mile? There was definite evidence of cooling in Holland (eyewitness visual accounts in Dutch landscape paintings of the time). Greenland became cooler (the Viking settlement could not survive it)

"A Scene On the Ice Hendrick Avercamp (1585-1634), The Netherlands; inspired by the harsh winter of 1608. Note that scenes like this, although now considered "typical" of the LIA, were only painted during 1565-1665."

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

Notice that the cooling event is well documented in North America and Europe in the mid-17th century. It was a very unusual time. There are indications that China and Africa were also affected.

Pattylou, I"ve read that the Sahara was a lush tropical region thousands of years ago. Would you like to call that a vagary of paleoclimate? If we could understand what happened to that region to make it a desert, it would be valuable information for the population of the world. If it could happen in the Sahara, it may happen elsewhere. Desertification happened to the Harappans. What causes these drastic changes? Paleoclimate becomes a very important issue here.

Bir Tarfawi and Bir Sahara: A Case Study. In historic times Bedouin traders have used the well into the Nubian Sandstone to water their camels during trading safaris from Sudan to the Nile Valley. Have humans actually lived here in times past? What is the evidence for this, and what does it mean if they did? Cross-section through the Bir Tarfawi depression shows how wind deflation has slowly lowered the basin. Oldest lakes are the highest, and youngest are the lowest.

Bir Tarfawi and Bir Sahara show clear evidence for intervals of permanent lakes between about 125,000 and 80,000 years ago. They also show evidence of wetter than present conditions between 11,000 and 6000 years ago. In the lakeshore deposits of 100,000 years ago there is evidence that humans made permanent settlements and hunted lions, hippos, zebras as well as smaller game. To support these large animals requires about 600 mm of rainfall each year, about twice what Boulder receives! There is no evidence of permanent lakes in the hyper-arid Sahara during the Holocene (the last 10,000 years), but there is evidence that humans lived in the region and hunted grazing animals. This requires more rainfall than present (which is about zero).

http://www.colorado.edu/GeolSci/courses/GEOL3040/concepts8910.doc

Don't just take my word for it that the Sahara was green... This is research from the University of Colorado at Boulder. (my boldface)

As far as Arctic warming, some think that polar bears are in danger, but they did not go extinct during a pre-LGM period.
 
Last edited by a moderator:
  • #35
Dear Nile Queen,

You are on a very different page than me. In brief, you are using 4 billion years worth of history to argue variability in climate. I think this approach is rather a bit like stating the blindingly obvious.

I am arguing a simple causal relationiship between the last 150 years of human activity and a warming climate.

In other words, we approach the question in two very different ways.

Here's a fun activity. What is the probability that the warming we have observed, would occur naturally... in any random 150 year period... of the past millions of years, without human contribution?

We probably won't have a very productive interaction.

:smile:
 

Similar threads

Replies
7
Views
5K
  • Earth Sciences
Replies
2
Views
3K
Replies
1
Views
1K
Replies
180
Views
31K
  • New Member Introductions
Replies
1
Views
580
  • Earth Sciences
Replies
3
Views
3K
Replies
17
Views
6K
Replies
73
Views
13K
Replies
2
Views
4K
Replies
3
Views
2K
Back
Top