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Arctic sea ice melt - natural or man-made?

Posted on 9 June 2008 by John Cook

Arctic sea ice has declined steadily since the 1970s. However, the 2007 summer saw a dramatic drop in sea ice extent, smashing the previous record minimum set in 2005 by 20%. This has been widely cited as proof of global warming. However, a popular mantra by climatologists is not to read too much into short term fluctuations - climate change is more concerned with long term trends. So how much of Arctic melt is due to natural variability and how much was a result of global warming?

The long term trend in Arctic sea ice

Global warming affects Arctic sea ice in various ways. Warming air temperatures have been observed over the past 3 decades by drifting buoys and radiometer satellites (Rigor 2000, Comiso 2003). Downward longwave radiation has increased, as expected when air temperature, water vapor and cloudiness increases (Francis 2006). More ocean heat is being transported into Arctic waters (Shimada 2006).

As sea ice melts, positive feedbacks enhance the rate of sea ice loss. Positive ice-albedo feedback has become a dominant factor since the mid-to-late 1990s (Perovich 2007). Older perennial ice is thicker and more likely to survive the summer melt season. It reflects more sunlight and transmits less solar radiation to the ocean. Satellite measurements have found over the past 3 decades, the amount of perennial sea ice has been steadily declining (Nghiem 2007). Consequently, the mean thickness of ice over the Arctic Ocean has thinned from 2.6 meters in March 1987 to 2.0 meters in 2007 (Stroeve 2008).

 

Global warming has a clearly observed, long term effect on Arctic sea ice. In fact, although climate models predict that Arctic sea ice will decline in response to greenhouse gas increases, the current pace of retreat at the end of the melt season is exceeding the models’ forecasts by around a factor of 3 (Stroeve 2007).

 


Figure 1: September Arctic Sea Ice Extent (thin, light blue) with long term trend (thick, dark blue). Sea ice extent is defined as the surface area enclosed by the sea ice edge (where sea ice concentration falls below 15%).

What caused the dramatic ice loss in 2007?

The sudden drop in sea ice extent in 2007 exceeded most expectations. The summer sea ice extent was 40% below 1980's levels and 20% below the previous record minimum set in 2005. The major factor in the 2007 melt was anomalous weather conditions.

An anticyclonic pattern formed in early June 2007 over the central Arctic Ocean, persisting for 3 months (Gascard 2008). This was coupled with low pressures over central and western Siberia. Persistent southerly winds between the high and low pressure centers gave rise to warmer air temperatures north of Siberia that promoted melt. The wind also transported ice away from the Siberian coast.

In addition, skies under the anticyclone were predominantly clear. The reduced cloudiness meant more than usual sunlight reached the sea ice, fostering strong sea ice melt (Kay 2008).

Both the wind patterns and reduced cloudliness were anomalies but not unprecedented. Similar patterns occurred in 1987 and 1977. However, past occurances didn't have the same dramatic effect as in 2007. The reason for the severe ice loss in 2007 was because the ice pack had suffered two decades of thinning and area reduction, making the sea ice more vulnerable to current weather conditions (Nghiem 2007).

Conclusion

Recent discussion about ocean cycles have focused on how internal variability can slow down global warming. The 2007 Arctic melt is a sobering example of the impact when internal variability enhances the long term global warming trend.

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Comments 451 to 500 out of 529:

  1. Patrick, I recall Quietman saying that he did not trust RC and, as a result, did not read it, althoug his readings (and links) have included niceties like the OISM page. That's the point of my question above. Nice link on Singer. This is the kind of reason why I'm always septical of "skeptics" on blogs. As of today I've seen perhaps 2 or 3 real ones. Ironically, they wouldn't even shape their thinking in terms of "agreeing" or "disagreeing" with AGW, wchich is a little to crude a way to put things.
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  2. Worth quickly getting back on topic: Arcic sea ice extent has taken a serious hit and would have to grow now at the same kind of rate seen in November to catch up with last year's maximun. Kinda strange. I expect some weather system pushing the ice around and possibly compacting it, but area as shown by cryosphere today seems to have the beginning of a dip also. Hard to tell what's going on. http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png
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  3. Philippe Actually it's the hockey stick site. And yes I will read a link that goes to RC when it's used as a reference to see what it refers to, I just don't go there on my own accord. As for chaotic inputs, there are simply too many. The earth breathes much more often than thought, the solar wind has erractic effects and tectonics which nobody at this site appears to understand the consequences of. Then chris reads the terms for Thermodynamic Laws, which were intended for use in engineering closed systems ONLY and tells me that they can be applied to climate. Sorry but that IS where this whole argument falls through. They DO NOT apply to open systems. In order to make these rules apply to an open system you would have to know the EXACT nature of ALL inputs and the simple fact is nobody alive knows these. The evidence is in the CONSTANT discovery that things are not what they appear to be. And I REALLY have trouble accessing this thread at this point. My references have already been posted in the various threads at this site (mostly under volcanos) so I am not posting them again.
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  4. ps I discussed with mu friend the use intended and he agreed that it does apply to this argument as well. So it actually is not out of context.
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  5. "would have to know the EXACT nature of ALL inputs " With regards to the difference between 2 and 3.0001, what would you say about the difference between 2 and 2.9999 ?
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  6. So you don't go to RC on your own accord but you'll go to OISM (and link it), Beck's and what not. Right. Whatever.
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  7. Where in an open system does conservation of energy not apply if one accounts for the inputs and outputs? Same for mass, entropy (not conservation of, but you get the idea), etc...
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  8. You're also suggesting that RC is less reliable than a purely political source (Morano's), which you read and linked. Whatever, again. But that's not all. In our exchange about Mars' climate, you first suggested an argument valid IF (emphasis yours) there was a correlation with Earth' climate. After I pointed that there was no correlation, you come back saying "You are right of course in that there is no correlation between Mars's climate and Earth's" as if that shows no contradiction to your previous proposition. Then you follow with some confused mumbo-jumbo. That's another kind of thing I'm wondering about. Granted, all of us make mistakes and dislike owning them. How many mistakes do you think you can be exonerated from before doubts arise about the good faith? In that same thread, you go on with increased speed of the solar wind as if it is relevant to the Earth's energy budget. I did not elaborate at the time, because I could not see what you were talking about. I still can't. Anyone is free to correct me if I'm wrong, but AFAIK, solar winds are made of ionized particles. The big difference with photons (solar irradiance) is that they travel a lot slower than light, and they have a significant mass and a charge, which is why they can be deflected by the Earth' magnetic field. That is also what makes them of little to no relevance to the planet's energy budget. Where did you ever see a study assigning a forcing to solar winds that would be relevant to tropospheric/stratospheric temperatures? Is there anything in the article you link suggesting that the superhot microflares (which you seem to allude to) actually increase the total IR radiation (how heat is tranported in the absence of a medium to conduct it) leaving the Sun for the Earth? Nothing of the sort. That's yet another example of a cite that does not support your argument and is not even really related to it. How many of these can be ascribed to good faith? If it is really good faith, what else does that indicate?
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  9. Just a small point Phillipe, -- the earth's energy budget is dependent on total solar radiation not just IR.
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  10. Quietman - where in the above comments were your friend's and chris's comments about thermodynamics?
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  11. Mizimi, I am quite aware of that, it's not the point. The point is that ionized particles do not play a significant part in that budget. What is usually considered for Earth' heat budget is TSI, which is light. The remark about IR referred to the possibility that more "heat" (Quietman's words) would be "carried" by the solar winds, the equivalent of an increased TSI, with the increase being in the IR range. The paper cited did not approach that at all.
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  12. Re 441: "Re: "new equilibrium temperature" discusses thermodynamic laws, implying a closed system. The earth has no equilibrium temperature, it constantly changes. GHGs do control it's limits but never achieve "equilibrium" because the earth "breathes". " The equilibrium in this context is a long-term equilibrium. The equilibrium temperature may refer to the average temperature over time. If the average temperature is higher, more LW radiation goes to space, cooling the climate system off, etc. It is not exactly that simple, of course, because of feedbacks, and the nonlinear dependence of blackbody radiation on temperature, and the potential for changing the spatial and temporal variability of the temperature for a given average. However, the concept still works, as part of a longer-term equilibrium climate. There must be limits to the unforced variability (true that the limits could be a function of time scale), or the probability would be much higher that nothing other than bacteria be alive right now.
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  13. Re # 453 Quietman, you are being decidely naughty and attempting to use contrived misunderstanding and misrepresentation as an "argument"! I've desrcribed explicitly how I'm using the term equilibrium (see post #446, for example). Nothing I've said contradicts the "Laws of Theremodynamics"! Your "argument" seems to be (post #454): "I discussed with mu friend the use intended and he agreed that it does apply to this argument as well. So it actually is not out of context." That's just silly. Why not try to be explicit? Read my post #446, and explain explicitly where you disagree. Leave you "friend" out of it. Or better still, get your friend to engage with the arguments at first hand...
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  14. chris In order for this "equilibrium" equation to gice the correct result you need to have all the correct data. You do not. It's just that simple. Right now you have a GIGO situation. Why? Because important factors are ignored as "being insignificant". Gravity is a weak force, so weak we can't actually figure out what it actually is. But it has a large effect and it's just one factor left out of the equation. The solar wind is another. It's brushed aside as "insignificant", only TSI is important. But a solar flare increases not just the velocity but the thermal energy of the solar wind and this factor is ignored. I understand why it was ignored 20 years ago but with what has been learned in the last few years there is no excuse for ignorance. The same goes for tectonic heating. It's viewed as "business as usual" when in fact it has increased to dangerous levels. Why? Because we are stuck in this "it's AGW" fantasy that Hansen started.
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  15. ps I would not recommend living in the midwest for much longer.
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  16. OK, so I'll repeat the questions I had for you on the Mars thread. I don't understand what you're trying to say and I don't see anything in the article you link (on the Mars Thread)that clarifies it. How does the solar wind "carry" heat? What is your definition of heat? How do you think that heat is normally transmitted through space? What scientific references do you have that particles winds participate in the Earth' energy budget
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  17. The vast majority of solar energy output is radiation - 'TSI' - it is mostly thermal radiation, with the spectrum of a blackbody (but not quite because the temperature varies within the photosphere, both horizontally and vertically, and the source of the radiation to space is distributed vertically over that 'surface' layer; short wavelengths (< 100 nm) and very long wavelength (> 1 to 10 cm) emission is over and above that of a blackbody of photospheric temperatures (in a range near 5780 K); the energy at these wavelenths is more variable but a small fraction of the total (Wallace and Hobbs, p.323 graph). The short wavelength (<100 nm) emission is nearly all from the corona and is about 3 ppm of solar TSI; wavelengths less than 200 nm account for about 0.01 % of solar TSI (Wallace and Hobbs, pp.327-328). A typical velocity of the solar wind is 500 km/s at Earth's orbit. Solar wind speeds and densities are quite variable. What is the order of magnitude of the power per unit area? From: http://hypertextbook.com/facts/2005/RandyAbbas.shtml density: 3 to 500 atoms per cm3 (essentially 3 to 500 protons and 3 to 500 electrons) (I'm not sure but the higher figure might be for closer to the sun) speed: 495 km/s, 500 km/s, 700 km/s, can get to ~ 890 km/s (3.2 million km per hour). " It is the supersonic outflow into interplanetary space of plasma from the outer atmosphere of the Sun. Its is composed of positive ions and electrons, with the ions being almost entirely composed of protons, about 95% to be exact. The elements that make up the Solar Wind are Hydrogen (95%), Helium (4%) and a mixture of Carbon, Nitrogen, Oxygen, Neon, Magnesium, Silicon and Iron at < 1%. " The average density of the Solar Wind is 4.0 atoms per cubic centimeter. Which is pretty small if you think about it, especially since the Solar Wind is responsible for deflecting the tails of comets away from the Earth. " The Solar Wind is constantly being blown off from the Sun at speeds of about 400-500 km per second. If you were to travel at 450 km per second you could travel around the entire world in 85 seconds! " -- Density 6.02 atoms/cm3 = 10^4 atoms/L, divide by 6.02 * 10^23 atoms/mol: Density 10^-19 mol/L = (for protons) ~ 10^-19 g/L = 10^-19 kg/m3 -- From: http://www.windows.ucar.edu/tour/link=/sun/wind_character.html http://www.windows.ucar.edu/tour/link=/sun/images/wind_character_big_jpg_image.html density ranges mainly between 1 and 100 protons per cm3, wind speeds mainly between 300 and 700 km/s and in the graph remain between 200 and 800 km/s but can sometimes get above 800 km/s "At the orbit of the Earth, the solar wind has an average density of about 6 ions/cm3" "The sun is flinging 1 million tons of matter out into space every second!" Temperature ~ 150,000 K - http://hyperphysics.phy-astr.gsu.edu/Hbase/kinetic/kintem.html#c2 http://hyperphysics.phy-astr.gsu.edu/Hbase/kinetic/idegas.html#c2 v(rms) = sqrt(3*k*T/particle mass) = sqrt(3*R*T/molar mass); k= 1.38066 * 10^-23 J/K R = 8.3145 J/(K mol) v(rms) solar wind = to make a long story short, much more energy is in the macroscopic motion than in the thermal motions of particules following the average motion; ...
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  18. Phillipe See patricks comment. I don't remember where I saw the articles, I think at Science Blogging (Imagenova). Patrick Thank You
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  19. p.326 Wallace and Hobbs: top of photosphere = bottom of chromosphere, has a vertical minimum in temperature at about 4300 K; chromosphere about 2500 km thick, top of chromosphere temperature on the order of 100,000 K. http://hypertextbook.com/facts/2005/RandyAbbas.shtml 500 km/s and 500 ions/cm3 agree with Corona temperature of 3.6 million K Solar wind: - near Earth, temp ~ 970 K - "Latest Solar Wind Values" (Jun 10 or 12 of 2005?) ~ temp ~ 36,000 K "during periods of greater sunspot activity it shows corresponding increases in density, temperature, and velocity" p.326 Wallace and Hobbs: Solar wind at Earth ~ 500 km/s, temperature can "occasionally" approach 1 million K. v(rms) (km/s) for T (K) ... 4.99 ......... 1,000 .. 15.79 ........ 10,000 .. 49.9 ........ 100,000 . 157.9 ...... 1,000,000 . 274 ........ 3,000,000 . 300 ........ 3,600,000 So the kinetic energy of the average motion dominates in the total kinetic energy of the particles. Energy per kg at T ~ 1 million K, solar wind speed ~ 900 m/s (PS because the thermal motion is random, square the speeds seperately before adding; multiply thermal energy by 2 for electrons + protons): 1/2 [(900,000 m/s)^2 + 2*(157,900 m/s)^2] = 0.43 TJ/kg Electrical potential energy per proton electron pair: 13.6 eV. 1 eV = 1.602 * 10^-19 J. Electric potential energy per mol ionized hydrogen: 1.31 MJ. Energy per kg is approximately 0.0013 TJ, less than 1% of the kinetic energy of the particles. ----- CORRECTION of comment 467: Density 6.02 atoms/cm3 = 6.02 * 10^4 atoms/L 6.02 protons/ cm3 ~= 10^-19 kg/m3 100 protons/ cm3 ~= 1.7 * 10^-18 kg/m3 0.43 TJ/kg * 1.7 * 10^-18 kg/m3 ~= 0.73 uJ (microjoules) per m3. 0.73 uJ/m3 * 900 km/s = 0.66 W/m2 = 0.048 % of TSI That's the energy of the solar wind - well, near the high end of it's range. From the more common numbers (using Temperature of 150,000 K, I'm not sure if that's average or above average or what, but it shouldn't make more than a few % difference): 500 km/s, 6 ions/cm3: 0.0064 W/m2 = 0.00047 % of TSI. Well, if the Earth's magnetic field could focus that energy onto the Earth, perhaps 100 times, the effect would be commonly: 0.64 W/m2, 0.047 % of TSI near high end: 66 W/m2, 4.8 % of TSI. The last case would be HUGE. But how would the magnetic field do that? I don't think that's how it works. The magnetic field deflects the solar wind, but the solar wind (and the interplanetary magnetic field it carries along) distort the geomagnetic field. variations in the solar wind can resonate with particles (electrons) within the geomagnetic field, boosting their energies: "SOLAR WIND MAKES WAVES; KILLER ELECTRONS GO SURFING? http://www.nasa.gov/centers/goddard/news/topstory/2003/0904magwaves.html" But how much total energy is involved in that? And what ultimately happens to it? Aside from those questions, how much multidecadal variability is there in the solar wind? Changes in the magnetosphere can affect the E-region dynamo of the ionosphere. In this region, winds driven by differential heating produce electric fields and currents because of differences in mass and radius of gyration between electrons and the much heavier ions; electrons are much more tied-down to magnetic field lines. If winds and pressure distributions were altered in the E-region and F-region of the ionosphere, this wouldn't have much direct effect on much of the mesosphere, and very very little on the stratosphere and troposphere, because it is such a small amount of mass in comparison. If there is a significant effect, it would have to be (I think) by wave-mean interactions. Maybe the lower thermosphere winds could alter vertical momentum transport to-and-from the mesophere, thus altering upper mesopheric circulation, ... thus altering lower mesospheric circulation, ... thus altering upper stratospheric circulation, ... thus altering lower stratospheric circulation, ... thus altering tropospheric winds, thus altering climate, though not clearly with an immediate net warming or cooling effect. (PS variations in TSI would likely have significant impacts on the upper atmosphere because of the larger variability of UV radiation compared to total TSI variability). Everything is connected, but everything is not connected equally. There are a lot of missing and fuzzy links here; the greenhouse effect as a driver of climate change is much better understood.
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  20. Thanks Patrick. And Quietman, If you interpret any of this as support for your contention that solar winds are participating in a significant way to surface temp increase, I think you are deeply confused. However, as I said bebefore, if you have science articles saying so (not just loosely related), link them. I am still to discover the logic that leads you to distrust RC but trust Marc Morano for scientific judgment unaffected by politics.
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  21. Philippe My reason for posting my friends comment: chris at 21:22 PM on 10 January 2009 "Equilibrium" and "thermodynamics" are certainly not only engineering concepts. They are fundamental to all processes in the natural world including all of the processes of life. Please note the last 7 words. As for Marc Morano, I don't know who that is. I assume that uou refer to the author of one of the articles. I need to point out that I don't pay attention to who the writer of an article is, only who they quote and what is contained in the quote.
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  22. 471: "....including all of the processes of life." are the last seven words of: "Equilibrium" and "thermodynamics" are certainly not only engineering concepts. They are fundamental to all processes in the natural world including all of the processes of life. Presumably you have a point to make Quietman. Arch insinuation is a poor substitute for clear explanation. I expect that if you were able to state your point clearly we could easily clear up your problem with my sentence. Why not have a go?
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  23. You're full of it Quietman. You linked Marc Morano's propaganda twice in post #12 of the "Determining the long term solar trend" thread. His name even figures on the link's tail. You're in essence saying that you linked stuff that you did not read. You're all fussy about Wikipedia and RC but applied no scrutiny whatsoever to Morano. What the heck? How could this qualify as a truly skeptical attitude? If you don't know who Morano is, you'd better learn before linking the stuff he puts together, shouldn't you? Wouldn't that be a reasonable expectation for a "skeptic"? You say "I don't pay attention to who the writer of an article is, only who they quote and what is contained in the quote." How does that make any sense? Why is it that the author quoted in an article is more important than the author of the article itself? What if an author is quoted in disagreement? That's total nonsense. Your excuses for intellectual dishonesty are getting lamer every time. If you don't care who writes an article, but only who it quotes, then you should not have a problem reading articles by that much maligned author from RC (whom you allude to but never named), so long as he quotes authors you like. However, you indicated that you distrust the entire site by saying "I don't read RC." What a load of dung. I guess since you didn't read the Morano's stuff you linked either, you have some sort of internally consistent attitude. Whatever. As for your thermodynamics problem, it was not among my questions, solve that with Chris. I do think, however, that my grasp on thermodynamics has nothing to envy to yours. About Patrick's clarification, if you believe that it supports in any way your contention that solar winds participate in increasing surface temps, first try to articulate clearly how that would work (with the appropriate quantities analyzed) and/or link work from real scientists that would do that. I'm not talking about loosely related articles that do not approach the subject. I want to see actual scientific treatment of the hypothesis. I'm all ears.
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  24. PS: that same post# 12 of yours links the ever so funny Roy Spencer beating his drum with the rumbly words of "the sloppy science of global warming." Roy Spencer's own sloppiness, fantastic ideas and incompetent mathematical treatment were exposed by the links I gave in this thread's post #437.
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  25. I guess what's good enough for Mann should also be good enough for spencer. So that means that you will never trust Mann again as well?
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  26. "So that means that you will never trust Mann again as well?" Mann's results have been largely confirmed; McIntyre and McKitrick's (spelling?) analysis was flawed. Roy Spencer's analysis is sloppy and unconvincing.
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  27. Are you yrying to change the subjet? You don't seem to get it. Spencer does not even realize that his mathematical argument is moot. He is showing what he believes to be some form of data analysis, that he believes demonstrate something when the effect shown is an inherent property of the mathematical treatment. It does not analyze the data at all, and he has no clue about it. PhD or not, he does not understand what he's doing. That's way beyond anything Mann was ever accused of, real or not. There is no way that something like that would ever make it through peer-review, even if Legates worked on it with buddies of his. The fact remains that Spencer's media communications on attribution of the rise in CO2 are pure fantasy and contradicted by all the available evidence. Spencer has evidently not tried to publish anything about it, he knows better. The fact remains that Spencer and Christy's handling of the UAH/MSU errors was way below anything necessary for the so-called skeptic crowd to scream fraud all over the internet. Yet I don't hear your voice on that. Could that be an example of one-sided skepticism? My questions about Morano still stand. What exactly was the thought process there if any? My questions about the solar wind still stand. I'd love to hear of a possible mechanism with even a vague idea of the resulting heat budget.
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  28. Yes Philippe, only Sceptics screw up, Alarmists never do. I think the horse has been dead for a while already.
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  29. ps I wasn't changing the subject, just pointing out that your insistance on focusing on people is exactly the tactics that alarmists always use. You personally did not prove anything. You are taking someone elses word. Patrick already showed me what he considers the error in Spencer's argument and I believe him.
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  30. Patrick Mann's worhas been disproven in the same manner that Spencers paper was. Plug any number into the hockey stick and it will always be a hockey stick.
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  31. ps The alarmists will always defend the hockey stick but everyone already knows it's flawed. Same issue, piss poor statistical modelling.
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  32. Focusing on people? Like "skeptics" focus on Mann and Hansen? You brought up citations by Morano and Spencer, not me. Heck you even throw in Robinson and the OISM, and Beck. Since you showed plenty of "focus" on the persons of Mann and Hansen, why should I think twice about "focusing" on all these funny characters you bring up? Spencer's paper? What paper? A blog post is not a paper. However, it can indicate what the author is capable of. Didn't prove anything eh? Did you prove that solar winds are heating things up? I admit that would be a lot of work, let's bring the goals down: did you describe any kind of vague mechanism that could make that possible? Proof is a strong word. In fact, some would say that science does not provide any such thing.
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  33. (solar wind): Without a known physical mechanism, you could also look for statistically-robust correlations (as opposed to a one-off match-up) between solar wind and one or more climate-related variables. However, you'd have to compare this to such correlations with TSI to isolate the relationship... in other words, try looking at a component of variations in the solar wind that do not correlate with TSI or other known climate forcings... "Plug any number into the hockey stick and it will always be a hockey stick. " Not so. That may have been the case with McIntyre-McKitrick's work (I don't remember all the details off hand), but not Mann's. In the absence of other information, Mann, et. al.'s word on the subject surely must be given equal weight as McIntyre-McKitrick's statements. Other information: many other studies yeild similar results. Similar but not exact. Maybe that's the problem you see. Other results do not look exactly like a 'hockey stick' - but the importance of the results is that there has been a sharp rise in temperature in the later portion of the 20th century that is anomalous (in combined speed and magnitude) relative to the rest of the record, and late 20th century temperature values are likely the highest for as far back as one can go in these several-century to 2000 year reconstructions (there may have been another peak in warmth earlier in the Holocene but we may have gone above that already, too; at least we are close to it. And not far away from the warmth of the previous interglacial, for that matter. None of which by itself proves that this is anthropogenic and that warming will continue at least until the atmospheric CO2 level (plus other greenhouse gases, minus aerosol cooling, plus variations in solar TSI, etc, weighted by radiative forcing and efficacy, taking into account lag-time and longevity of responses and feedbacks, averaged over internal variability) stops rising. But the paleoclimatic record is not all of the available information).
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  34. "In the absence of other information, Mann, et. al.'s word on the subject surely must be given equal weight as McIntyre-McKitrick's statements." or you could look at the actual papers...
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  35. Philippe There is a large difference between those scientists that do NOT have an agenda making an honest mistake and those "scientists" WITH an agenda being decietful with the evidence and telling lies. Every single anomality can be explained by one of the multitude of climate forcings that cause the various cycles in the climate. The bottom line is where is the proof of AGW? And NO, peer reviewed papers in this particular field have become unreliable and simply unbelievable with their reliance on the CO2 fudge factoring that do not match reality.
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  36. "There is a large difference between those scientists that do NOT have an agenda making an honest mistake and those "scientists" WITH an agenda being decietful with the evidence and telling lies." Sounds like a perfect definition of Spencer/Christy, or Soon/Baliunas, or Loehle, etc... But of course, your skepticism would never turn its gaze to that side. If that's how you consider Spencer's ridiculous post on WUWT, once again, whatever. Not so sure I'd take your word on any aspect of "reality." Nothing personal, though, just that way of arguing you have. Like when you say you don't know who Morano is, or when you mention the possibility of climate correlation with Mars just before saying that, "of course there's no correlation." You know, I may be younger than you but I know bad faith when I see it.
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  37. "Every single anomality can be explained by one of the multitude of climate forcings that cause the various cycles in the climate." ... "The bottom line is where is the proof of AGW?" But most of the warming over the last century can be explained easily by CO2. Where is the proof that other forcings have any effect? Of course these are both over-simplifications. All forcings contribute; some are of opposite sign so the total change in forcing over the last couple centuries or so happens to be about that of CO2 alone. The climate may be more sensitive to some forcings because of spatial-temporal distributions (efficacy) (black carbon on snow), and some forcings may have different specific regional effects (aerosols); but (while solar and ozone effects on upper atmosphere above the tropopause - however, global warming in general may produce some of the same stratospheric circulation changes) there is no convincing case yet that we should expect the response to solar forcing to be amplified by a factor of 2 or 5 or 7 ... relative to that from CO2. --- Any single mistake by Spency, Soon, etc... could be attributed to an honest mistake, but multiple mistakes erring to one side can sometimes raise suspitions - moreover, they are mistakes - thus they are not correct. Obviously, Exxon has an agenda. And of what significance to the conclusions have any 'mistakes' by Mann, etc, yeilded?
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  38. "And of what significance to the conclusions have any 'mistakes' by Mann, etc, yeilded?" Please pardon the grammar. And of what significance have been any 'mistakes' by Mann, etc, to the conclusions? -- Marc Morano most definitely has an agenda. There are a class of people who refuse to accept the science because, from their perspective, either 1. government must be made small (enough to drown in your bathtub - Grover Norquist) and so any problem for which a government solution is a wise choice must therefore not exist; 2. Taxes must always be cut and never be increased, hence a CO2 tax, regardless of the logic, must be opposed in order to 'starve the beast' (so that it can be drowned in one's bathtub); 3. Any 'beliefs' by those on the other side of the political spectrum must be opposed; 4. Government policies will fail (well, of course, if you have no-bid contracts, silence whistle blowers, deprive programs of necessary funding...); 5. Anyone who does not pursue Laizze-Faire (spelling?) ultimately has a communist agenda, doesn't understand and value the free market (I do like free markets, I understand the logic, but they are not 'my lord and savior'); 6. Policies pursued to mitigate cliamte change will hurt the poor (but why should the government do something specifically to help poor people - I thought small-government conservatives were against wellfare); 7. in some cases, God is in charge and humans have no influence over anything; and/or God wants us to add CO2 to the atmosphere to bring about a garden of Eden (that's not what would happen); and/or God is going to destroy the world soon anyway; and/or seeing value in nature is somehow paganism (and yet valuing money is not?); and/or (I'm infering this one) they don't believe in evolution so why should they believe anything else from science (although there are noted exceptions - anti-religious people who accept evolution but are ideologically blinded to global warming; religious people who don't believe evolution but who see our destruction of the creation as a bad thing).
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  39. That would be "laisser-faire" Patrick. Indeed the vast majority of skeptics have little grounding to their skepticism in scientific realities. The real problem I see is that they don't even have a true skeptic attitude. What strikes me the most is the extreme scrutiny applied to all the evidence supporting AGW and the extreme complacency about anything opposing it. When you get "references" like Morano, the OISM, Beck and what not, that pretty much shoots down any possibility of dialog. The (very) few real skeptics I've encountered would not bring up that kind of nonsense, or anything that they did not scrutinize carefully. Perhaps that's why there are so few of them.
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  40. ""laisser-faire"" - Thanks! (I may be able to remember it by thinking 'laser fairy'.)
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  41. Regarding comment 469: "Aside from those questions, how much multidecadal variability is there in the solar wind?" On that point, my impression is that climate models are able to simulate the little ice age, which suggests that if the solar wind varied with total solar forcing back then the way it does now, setting aside possible nonlinearities in the magnetic field and climatic response that just happen to make it a bigger factor now, then it seems likely that the sun is not contributing a whole lot more (over twice as much, which is minimally what it would take to overcome anthropogenic forcing, assuming high end estimates of solar forcing and near-high end estimates of anthropogenic aerosol cooling, to make solar forcing dominant, and only just barely - anthropogenic effects would still be important, and greenhouse forcing even more so as it would be partly canceled by aerosols in that case, more than is expected) to climate change now than is thought. Same for TSI UV effects on upper atmospheric circulation - it is possible to imagine that there is some aspect of changing atmospheric circulation patterns and regional changes, aside from global average temperature increases, that has some special connection to TSI in UV - and for that matter, ozone depletion has had an effect on SAM (Southern Annular Mode); but the greenhouse effect also has direct effects on the upper atmosphere that may be similar. Directly-radiatively forced effects on the upper atmosphere (above tropopause) shouldn't have a lag time over one year (actually a few weeks??), whereas tropospheric and surface changes and stratospheric changes in response to those changes will have a lag time of over a decade, maybe ... well, it's more than one decade. So if solar forcing has not increased much since 1980... etc. ---- Regarding where I left off on comment 439: Rossby wave propagation properties of the basic state will not just vary vertically. Sloping reflective surfaces can change the horizontal orientation, resulting in changes in the north-south group velocities of waves between incident and reflected, and between incident and refracted... And Rossby waves can be/are refracted and reflected horizontally. The synoptic-scale wavelengths (midlatitude cyclone activity) cannot penetrate far into the stratosphere; The quasistationary Rossby waves (longer wavelengths) can propagate up provided the wind is westerly and not too fast (wavelength dependent). In summer, the winds generally reverse within some distance of the tropopause, becoming easterly within most of the stratosphere by volume (I'm not sure by mass offhand, as density decreases roughly exponentially with height). In the winter, the wind speed generally decreases up to a point but remains westerly up into the mesosphere; a point is reached where it speeds up again with height - this can occur in the lower stratosphere at higher latitudes from the tropopause-level average maximum westerly winds (at high enough latitudes, the average westerly wind increases with height from the surface up through at least the lower stratosphere (Holton, p.407)) - generally maximum winds are reached somewhere near the upper stratosphere/lower mesosphere (by geometric height) and then decrease again (Holton, p.407) - the summer hemisphere has a maximum in easterlies above the stratopause. I started with the idea of Rossby waves described by formulas that I think were derived with assumptions that some things were nearly constant with height and that the basic state horizontal wind shear is not a big factor in the IPV gradient. I'm not sure off hand how a more complete understanding will change the picture. Anyway, climate changes involving increasing horizontal temperature gradients in the upper troposphere and lower stratosphere (I don't know about upper stratosphere) could change how these waves propagate and thus cause changes to circulation patterns, including positions/strengths/qualities of prevailing westerlies and storm-tracks, by changing wave EP fluxes between the stratosphere and troposphere as well as by changing the storm track activity itself and the Hadley cells, etc. So is this what's happening?
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  42. " but the greenhouse effect also has direct effects on the upper atmosphere that may be similar. " No, wait. The total effect of solar brightenning, ozone depletion, and increased CO2,CH4,N2O,etc, are all expected to cool the lower stratosphere more at higher latitudes than at some lower latitudes, although there is some interesting complexity(IPCC AR4 WGI Chapter 9 ? see diagram on p. ?) the changes in north-south temperature gradients are quite similar for the lower stratosphere between CO2,CH4,etc and solar forcing, at least from mid-to-high latitudes - exactly what the direct effect of the greenhouse effect on the stratosphere is besides general cooling...?
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  43. Possibly contraction (increased pressure and temp lapse rates)?
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  44. Although this might be an effect more for the layers above the stratosphere. Not sure.
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  45. ... see IPCC AR4 WGI Chapter 9 p.675 http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf of course, these are annual average respones...
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  46. The cooling of the stratosphere and layers above due to a greater greenhouse effect will cause a density increase; the mass falls somewhat (except below some level where the effect of thermal expansion of the troposphere pushing overlying mass upward dominates). But in pressure coordinates, there is little change (pressure levels fall to lower geometric heights, following the mass distribution, with some adjustment due to the variation in gravity with height (a very minor issue for most of the mass of the atmosphere - actually, if I bring that up then I think I should also mention that the increased humidity of the troposphere should cause some slight increase in surface pressure and push the atmosphere upward just slightly). What I was wondering about, though, is what the direct radiative effect of a greater greenhouse effect is on the horizontal temperature variations of the stratosphere. Generally, the warmer parts of the stratosphere should cool the most; and also the parts which lose the most heating by LW radiation from below (surface and troposphere) - so I wouldn't expect the direct effect to have a strong cooling of the polar winter stratosphere, for example .
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  47. Upward expansion of the atmospheric mass and pressure levels by warming and additional moisture are distinct from the rising of the tropopause relative to pressure levels.
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  48. Your wealth of knowledge is impressive Patrick. I'm curious: are you a grad student of atmospheric physics? If yes, any specific area of study?
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  49. Not a grad student - yet.
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  50. Good luck with your next mid terms!
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