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Comments 34851 to 34900:

34851. Bart Verheggen at 06:20 AM on 16 August 2014
       Survey confirms scientific consensus on human-caused global warming
       

       rkrolph,

       
       I think Q5 in the FAQ answers your question.

       Q3 asks about the contribution of GHG and other factors to Global Warming. This blogpost explains why it may be better to exclude the 'undetermined' answers when calculating a consensus percentage.

34852. MattJ at 06:13 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Re #1444

       Thanks, Tom, for your long and thoughtful reply. You did clarify several points well. But that integral is hard to do for a climate system, isn't it? That is why I am groping for a simpler way to explain it. Using a completely different form of the 2nd law and observing entropy increasing in each step of the process still seems the best way to go rather than take the article's approach.

       Then to the skeptic who still object, "but you have heat going from cooler to hotter", we can say, "but entropy did increase, so there is no violation".

       The problem with this approach is that it requires explaining to the layman what entropy is and how to track it and estimate it. Then there is still the problem that the idea that the second law says only and exactly "heat never travels from colder to hotter" is quite entrenched in the minds of many. I have encountered many, for example, who seem to have engineering thermodynamics backgrounds who still have this entrenched.

34853. Dikran Marsupial at 05:59 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ I have already answered the question, backradiation does not "heat  up" the surface any more than a blanket "heats up" the person beneath it.  It causes it to be warmer than it would otherwise be, by reducing the rate at which heat is lost.  The net transfer is still from warmer body to cooler body.  Sadly this doesn't seem to fit within your comprehension of the problem, which appears to be because your comprehension of the second law is defficient, and sadly you have too much hubris to recognise this.

       Just to be clear:

       (i) there is indeed LWIR coming from the upper atmosphere, it is usually known as "backradiation"

       (ii) The stratosphere is cooler than the ocean surface.

       (iii) The part that I disagree with is the "heat up" bit, which is incorrect, "causes to be warmer than it would otherwise be" would be closer to being correct as the net transfer of heat is from the surface to the atmosphere.  I have already explained this to you (using a blanket as a metaphor).  It would be correct to say that upwelling IR from the surface "heats up" the upper atmosphere.

34854. MattJ at 05:43 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Re #1434 "Dikran Marsupial at 04:51 AM on 15 August, 2014
       
       

       "I am always amazed how rare it is in discussions of climate change for people to be willing to answer simple direct questions and will go to such great lengths to avoid doing so!"

       But how can you be amazed at it? You yourself have never answered the "simple direct question" I put to you to keep you from wandering down the wrong way and disproving what I never said instead of actually addressing the real issue.

       The "simple, direct questions" I am referring to are from #1435, where I wrote: simply answering "since you are still requiring radiating CO2 molecules in a -20C stratosphere to heat up an ocean layer that is on average above +20C" with "I pointed out this is not the case is not helpful. Which part of it do you disagree with? Are you going to claim there is no LWIR coming from the stratosphere? Or that the stratosphere is warmer than the ocean surface?

       That is three simple questions you never answered. So you are in no position to complain.

        

34855. Dikran Marsupial at 05:38 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ wrote "At no time did I say the 2nd Law is actually violated. ", no, but you were claiming that there must be "some other change" that prevents the violation.  This is not the case, as the translation of Clausius' text book explains very clearly (the interchange is "compensated").  That was the point I was getting to with the thought example that you consistently avoided engaging with.

34856. Dikran Marsupial at 05:36 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ "But there is another problem which I also pointed out: the wording, despite what the article claims, is NOT even from Clausius. Yet the article presents this as his own words."

       Given that Clausius did not appear to have published anything himself in English, to suggest that the article presents anything as his words is utter nonsense.

       There is also the point that the statement in the book may not be the only one he made, if anyone can track down the translations of his papers, or the translation of the second edition of his textbook, you may well find them there.

34857. Dikran Marsupial at 05:33 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ wrote "Well, look at how long it took for you to recognize that I was right, my quote of Clausius is correct (in #1446), the author's version is not."

       No, the version given in the article is perfectly adequate as the greenhouse effect does not require "some other change, connected therewith, occurring at the same time" because the back-radiation is already compensated by the upwelling IR from the surface.  The definition given in the article is also merely a rephrasing of the version given in the foot note.  It isn't wrong, the difference between the two definitions is irrelevant in this particular case, so insisting on it is ridiculous pedantry.

       ""Heat generally cannot flow spontaneously from a material at lower temperature to a material at higher temperature."

       is an equivalent statement to

       "Heat cannot of itself pass from a colder to a warmer body"

       which appears in Clausius' textbook.  Note this phrase is translated from Clausius as the footnote gives the German wording of "of itself".  "Spontaneously" is a perfectly reasonable synonym for "of itself" in this context, and the "generally" refers to the possibility of there being "some other change...", which happens not to be relevant in this case.

       Please stop digging.

34858. MattJ at 05:32 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       #1436 "MattJ is saying that photons do really pass from B to A but in so doing the 2nd Law of Thermodynamics is violated and this phenomenon thus requires explanation."

       This is what I find distressing about SkS: many people here get on their high horses in defense of science — yet show they cannot even read well enough to do it. At no time did I say the 2nd Law is actually violated. On the contrary: I explained many times that I see only an appearance of violation, and that I know from the derivation of Kirchoff's and Stefan-Boltzmann radiation laws that it is not violated.

       Why, I repeated this so many times that a moderator accused me of "excessive repetition". But what else am I to do with responses that either misread what I wrote or ignore what I already said?

34859. MattJ at 05:23 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Re #1445

       No, Phil, he does NOT "get it right". Nor am I the first to point out this error. It was pointed out long ago (#955), yet nothing was done about it.

       What the article actually says is: "Heat generally cannot flow spontaneously from a material at lower temperature to a material at higher temperature."

       Do you see the difference now between what you said and what the article actually says? If, as you say, he had only used the word 'spontaneously', you would be correct. But he also put in the word 'generally', making it useless as a physical law.

       But there is another problem which I also pointed out: the wording, despite what the article claims, is NOT even from Clausius. Yet the article presents this as his own words.

34860. MattJ at 05:16 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Re #1448 Dikran says, "I really don't understand why there is so much skeptic [sic] interest in the very weakest skeptic [sic] arguments, such as this one, and the idea that the rise in CO2 is natural, where in both cases a bit of common sense is all that is required."

       Well, look at how long it took for you to recognize that I was right, my quote of Clausius is correct (in #1446), the author's version is not. That alone should show you that it does take more than just "common sense". When you put forth an alleged scientific explanation that can't even quote the Second Law correctly, you should expect enough dispute to generate a 1448 comment thread. By starting out with such a blunder, you make the weak skeptic's argument look much stronger than it actually is.

34861. Harry Twinotter at 04:51 AM on 16 August 2014
       Climate scientists dub this year’s El Niño “a real enigma”
       

       The trade winds have weaken in the last couple of weeks, and the SOI has been staying negative. Maybe a weak El Nino has begun. The ocean warming is becoming so consistent perhaps the El Nino pattern cannot organise itself.
       
       http://www.bom.gov.au/climate/enso/#tabs=Overview

       Moderator Response:

       [JH] Link activated.

34862. TomR at 03:38 AM on 16 August 2014
       Climate scientists dub this year’s El Niño “a real enigma”
       

       A recent study reports that the east to west tradewinds at the equator off South America have been much stronger in the past decade than ever since record keeping began.  Another study reports that the warming on the Atlantic is creating high pressure there in the upper troposphere some of which is spilling down on the west coast of South America magnifying the tradewinds (MacGregor et al. Nature Climate Change 8/7/14), which may be why they have been so strong.  

       The El Niño requires a relaxing or reversal of those tradewinds but the winds have not been cooperating from what I have read.  Might not this is the reason that the El Niño is not occurring?  I think that MacGregor states that the effect which he documented will at least temporarily decrease the frequency of El Niño years and had been and will continue push a little more of the global warming heat into the oceans for an uncertain amount of time.

34863. joeygoze9259 at 03:36 AM on 16 August 2014
       Climate scientists dub this year’s El Niño “a real enigma”
       

       Just a slight correctin, NOAA has chance of El Nino down to 65%

       http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

       Moderator Response:

       [JH] Link activated. 

34864. jetfuel at 01:54 AM on 16 August 2014
       Antarctica is gaining ice
       

       Since 70 meters of SLR=All of Antarctica melting, The 20 years from 1992 thru 2011 cumulative melt of .00006 of the 70 meters of potential SKL worth of land ice on Antarctica: .00006*7000 cm = .42 cm. At that rate per 20 year period, by 2100, there would be .42 * 4.5 = 1.89 cm. There is a lot of exponential increase in the rate of melt to get to 37 cm from less than 2 cm. In the end, even 37 cm is only .005 of Antarctica melted. The moon was at perigee this week and in some local areas tides along the US eastern seaboard were 16 cm higher than normal highs. A prelude of the effect of exponentially increasing melt through 2060? 

34865. Dikran Marsupial at 01:29 AM on 16 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       PhilippeChantreau indeed, but it is still able to generate a thread of 1448 comments! ;o)

       I really don't understand why there is so much skeptic [sic] interest in the very weakest skeptic [sic] arguments, such as this one, and the idea that the rise in CO2 is natural, where in both cases a bit of common sense is all that is required.

34866. PhilippeChantreau at 23:37 PM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Very interesting. This formulation makes the G&T paper completely moot. Their entire demonstration relies on faulty interpretation of the law.

34867. DSL at 23:31 PM on 15 August 2014
       Global warming is moistening the atmosphere
       

       denisaf, that's wonderful.  Now we can just sit back and wait until the tangible technological systems make more ethically sound choices. 

34868. CBDunkerson at 22:40 PM on 15 August 2014
       Global warming is moistening the atmosphere
       

       denisaf, this sounds like the old proximal cause vs distal cause argument;

       'Guns don't kill people, people kill people'

       'People don't cause global warming, technological systems (run by people) cause global warming'

        

       Sorry, but to me these arguments always read as sophistry at best, and in this case it doesn't even rise to that level. There are plenty of technological systems which don't contribute to global warming... and indeed, our only hope of stopping the process lies in developing cleaner technologies like wind and solar power. Humans are causing global warming. We actually started doing so thru land use changes before we even developed modern technology. 'Anthropogenic global warming' is an accurate term. 'Fossil fuel driven global warming' is an accurate term. 'Technological system driven global warming' is not, at least for some technological systems.

34869. Dikran Marsupial at 21:25 PM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       O.K., well I thought I'd go and look up Clausius' statement, and I found a translation of his works here:

       "The Mechanical Theory of Heat, with its Application to the Steam Engine, and to the Physical Properties of Bodies", by R. Clausius, Translated by John Tyndall, Edited by T Archer Hurst, 1867 (available via Google books)

       Yes, it was indeed that John Tyndall!

       Clausius' statement of the second law mentioned by MattJ can be found on page 117, and has an interesting footnote, which I have reproduced below:

       

       

       The footnote makes it very clear that I was wrong in that Tyndall, and I presume also Clausius (as he has an author's preface published in the volume) were well aware that there is a bidirectional transfer of heat between two bodies of different temperatures:

       "In the first place this implies that in the immediate interchange of heat between two bodies by conduction and radiation, the warmer body never receives more heat from the colder one that it imparts to it."

       However, it is in complete agreement with what I wrote about the second law applying only to the net flow of heat,

       "now it is to these compensations that our principle refers; and with the aid of this conception the principle may also be expressed thus 'an uncompensated transfer of heat from a cooler to a warmer body can never occur' "

       and thus the greenhouse effect does not violate the second law of thermodynamics because the surface imparts more radiation to the upper trophosphere than in receives in back radiation.  In Tyndall's terms it is fully compensated.

       Update: It seems unclear whether the translation was by Tyndall or Hirst, or possibly a bit of both as Tyndall translated the original papers and apparently worked with Hirst.  Tyndall certainly wrote the introduction.  However the central point remains as Clausius obviously approved the translation.

34870. BojanD at 20:38 PM on 15 August 2014
       Error identified in satellite record may have overestimated Antarctic sea ice expansion
       

       @michael sweet, thanks for the link.

       @MA Rodger, when you say that the size of error is not in doubt, I'm sure you mean the size of transition from V1 to V2 (or vice versa). However, I was alluding that there might not be a dichotomy, that even if V2 is much better than V1, there could still be a minor mistake lurking in it and I was merely hedging against it.

       As for the figure, you're making some unwarranted assumptions about my position regarding the Eisenman vs. Comiso. I've never stated or implied my absolute position, only relative one, a shift in position. In the beginning (starting with my first post) my position was almost aligned with Eisenman, but then gradually moved towards Comiso. And based on this NSIDC link by Michael, even 68% figure, which was very conservative to begin with, is stale, since it's stated in report: "Using the newer version of the algorithm, Antarctic extent trends agree much more closely with the trends from the NASA Team algorithm used by NSIDC." So my 'enigma' is pretty much explained by this and my new figure is probably more like 90%.

34871. Phil at 19:21 PM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ:

       Finally, concerning Phil's point. Yes, it was mentioned, but only later, and the author did not even seem to notice that he was contradicting himself,

       I'm sorry, but I cannot understand this point;  the OP correctly formulates the 2nd Law using the word "spontaneously" to indicate that exceptions to the flow of heat require "work". It does so in the 3rd paragraph, not "only later". I would suggest that you actually re-read the OP.

       I would re-iterate the my point,  that you seem to be having great trouble distinguished heat from energy flows. Dikran tried to help you with this, but you refused to let him, Tom is having another attempt; but fundamentally your remarks show that you know less about the physics of the greenhouse effect than you think you do.

34872. scaddenp at 18:51 PM on 15 August 2014
       Air pollution and climate change could mean 50% more people going hungry by 2050, new study finds
       

       Before this discussion gets completely derailed, the original bone of contention is whether new lands, rather than existing suitable land, can be opened for agriculture due to an improved climate closer to the poles, at the same rate as other lands are lost.

       I dont see the revelance of papers on existing forest conversion where its suitability already existed. I can find no suggestion in the paper that conversion of boreal forest to agriculture is due improved climate. The paper states that highest rates of conversion were just after WW2 when climate was colder. 

34873. jamesshaffer at 18:38 PM on 15 August 2014
       New Research Confirms Global Warming Has Accelerated
       

       These findings should not be left without proper attention. Whereas some decision makers and even environmentalists doubt whether a several degree temperature change makes any difference, this study clearly shows that the global warming and its consequences are accelerating. As it was discussed in the following research paper on global warming, http://place4papers.com/samples/global-warming-research-paper the average temperature increase can have serious consequences for the planet.

34874. Tom Curtis at 15:32 PM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ @1443, the formula for the Clausius inequality is:

        

       That only applies to cyclical processes, and is integrated over the cycle.  You will notice the variant integration symbol used to indicate that fact.

        

       The formula, ΔS ≥ ∫δQ/T, which I gave above is for any closed system, and uses a conventional integration.  That is, it sums over all energy transfers in the region under consideration, and for the time under consideration.

       The Fasullo and Trenberth diagram provides us with total average energy flows per unit time.  From that we can integrate over area and time if we want to, but the result will be the same as simply summing over the power flows in showing that the 2nd law is not violated by the exchange of energy between surface and atmosphere.

       Importantly for this discussion, this is shown without bringing in extraneous factors like the energy input from the Sun, or the energy outflow to space.  In fact, we can model a genuinely closed surface/atmosphere system and the principles involved in the energy exchanges will be the same.  The actual values integrated will not be, for the energy flows will change over time as the surface and atmosphere equalize in temperature.  Such a process would involve every means of energy exchange that actually exists in the atmosphere, including back radiation, and would result in a net increase in entropy.  Further, the surface would cool over time while the atmosphere warms over time.  It follows that back radiation does not violate the 2nd law of thermodynamics, and that neither does it warm the surface.

       We can extend this model by opening it to space, and compare to situations, ie, one with an atmosphere containing greenhouse gases, and one without.  If we do so we can show that the surface in the case with the atmosphere will cool slower than the surface without an atmosphere.  However, it will still cool so there will be no question of any violation of the 2nd law of thermodynamics or the atmosphere warming the surface.

       Finally, we can add in the Sun and find an equilibrium situation.  In that case, the surface equilibrium will be warmer with the atmosphere than without.  That, however, is because the slower rate of cooling for a given surface temperature with an atmosphere requires a warmer surface temperature for the outgoing radiation to match in energy the incoming energy from the Sun.  Thus, in this case, it is true to say that the surface is warmer than it would have been without the greenhouse gases, but it is the Sun that warms the surface, not atmosphere.  

       We might say colloquially that the greenhouse gases warmed the surface, just as we might say colloquially that a blanket warms us at night.  In both cases, however, it is strictly inaccurate.  A blanket will not "warm" a cold stone, and greenhouse gases will not "warm" in the absense of the incoming solar radiation because they do not warm at all, they merely slow the loss of heat.

       You comment:

       "But more important: when you say, "the cold atmosphere does not warm the warmer ocean" what do you think happens to the IR photons from CO2 high in the cold stratosphere when they meet the surface of the earth or of the ocean?"

       No.  I do not mistake the net flow of heat with the individual flows of energy.  Nor am I unaware that in the superior formulation of statistical thermdynamics the 2nd law holds only on average, and that the shorter the time interval the higher the probability that it is violated for that short term.  Thus, there are IR photons from the atmosphere that strike the ocean and transfer energy, but there are more IR photons from the ocean that do the reverse so that the the net heat flow is from ocean to atmosphere (and hence it is the ocean warming the atmosphere rather than the reverse).

       Finally:

       "[The] increasing wavelength of each of these stages of radiative transfer each shows an increase in entropy, so that entropy is non-decreasing, as the second law requires. It is even still non-decreasing in the case of cold stratosphereic CO2 adding heat energy to the thin but warmer surface layer on the ocean."

       The wavelength of IR radiation exchanged between atmosphere and surface is approximately the same for any specific atmospheric component, but the difference in wavelength between incoming SW radiation and outgoing IR radiation does indeed show the process to involve an increase in entropy, and to not violate the 2nd law of thermodynamics.

        

34875. denisaf at 13:21 PM on 15 August 2014
       Global warming is moistening the atmosphere
       

       It is disconcerting that this informative discussion of a climate change issue is misleading in using the term 'anthropogenic'. It implies that humans have produced the emissions that are contibutng to climate change. People have only made (bad) intangible decisions. It is tangible technolgical systems that have done the damage. Better understanding of this causative factor could well lead to improvements in coping with the effect of climate change.

34876. MattJ at 13:19 PM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Re 1441: Not that awful Trenberth diagram again! Sure, I know the diagram is correct, but people who are climate scientists simply have no idea how confusing it is to people who are not familiar with it. It looks like lots of things should add up that don't.

       But you say one has to do the integration — but then you don't do it. You are doing a sum of watt/m2, which is not even the right units for entropy. Nor are you doing the sum over a cycle/process, which is what the expression you gave for delta S requires.

       But rather than ask for that integration, what I think you really need, so what I will ask for is a clarification of the grounds of your assertion that "But the cold atmosphere does not warm the warmer ocean, and nor is their any apparent violation of the second law." That there is an apparent violation is pretty clear, since lots of people find it apparent. But more important: when you say, "the cold atmosphere does not warm the warmer ocean" what do you think happens to the IR photons from CO2 high in the cold stratosphere when they meet the surface of the earth or of the ocean? Aren't they almost entirely absorbed? And once absorbed, isn't all their energy converted to heat? How could these steps be anything other than "the cold atmosphere warming the warm ocean?

       At this point, I think Robert Murphy is a lot closer to answering my question. I have suspected it has a lot to do with the low entropy energy input from the sun driving the whole process, but even this leaves unanswered questions.

       In particular, if we follow a more modern statement than Clausius's (an idea I have been mentioning for a while), then the increasing wavelength of each of these stages of radiative transfer each shows an increase in entropy, so that entropy is non-decreasing, as the second law requires. It is even still non-decreasing in the case of cold stratosphereic CO2 adding heat energy to the thin but warmer surface layer on the ocean.

       It is much harder to make the same argument from Clausius's form, especially when the author does not even state his form correctly. Clausius NEVER said "Heat <b>generally</b> cannot flow spontaneously".

34877. Ian Forrester at 12:49 PM on 15 August 2014
       Global warming is moistening the atmosphere
       

       PluviAL the recent data from GRACE (Gravity Recovery and Climate Experiment) shows a net loss of ice mass from Anatctica.

       "Over March 2003 to July 2012, East and West Antarctica ice mass change was +97 ± 13 and −159 ± 9 Gt/yr, respectively, with accelerations +18 ± 10 and −31 ± 7 Gt/yr2 , respectively (2-sigma uncertainties) not considering GIA model error bounds. Mass change for the entire Antarctic Ice Sheet is also best modeled with a linear plus acceleration functional model and a stochastic model that considers temporal correlations, giving an ice mass trend of −58 ± 16 Gt/yr and an acceleration of −15 ± 13 Gt/yr2 ."

34878. scaddenp at 11:39 AM on 15 August 2014
       Facts can convince conservatives about global warming – sometimes
       

       I have also responded to your model question in the appropriate place.

34879. scaddenp at 11:37 AM on 15 August 2014
       Models are unreliable
       

       On another thread, Donny asks:
       "Let me ask one more question of the accurate models. ... when will the surface temperatures begin to significantly rise again? What do they predict? Also there are so many of them. ... which one should we believe? "

       Since no one else has, I will attempt a response.

       The question implies a considerable misunderstanding of GCMs and their output. Let's start with some basics. Firstly, models are evaluated in terms of their skill. A skillful model gives more information than a naive heuristic. (eg climate will be stay the same). For all the faults of models, (and modellers can quickly point to their deficiencies), they remain the best tools we have predicting future climate. Even the incredibly simple Manabe model from 1975 managed to nail 2010 temperatures pretty well. Secondly, GCMs for all their usefulness are not the basis for AGW and nor are the only way to estimate climate sensitivity to an increase in CO2. That can be done "bottom up" from pure physical consideration of feedbacks, or from empirical means. Whatever way, you end up with climate sensitivity likely in the range from 2-4.5.

       In terms of Donny's question, the next thing to understand is that models have no skill at decadal level prediction of surface temperature (and many other associated parameters). Over short times intervals, the surface temperature variability is dominated by ENSO. This is a chaotic ocean-atmosphere phenomena which is extremely difficult to predict even a few months out. In the El Nino phase, the atmosphere (and thus the surface temperature) gets a huge boost from heat stored in the ocean. Over last 15 years, La Nina or neutral conditions have predominated however. Climate however is about 30-year averages and the effects cancel out. Climate models are skillful estimating future 30-year average.

       So what do they predict? Well over a 30 year period, they predict the climate will be close to the ensemble mean. They predict that actual temperatures will follow a trace as variable as one of the grey lines on the graph at the bottom of the article. They do not predict a exact path. Rerun the same model with slightly different initialization and you get a different grey line. Do many runs on many models and you get that nest of grey lines which make up the model mean. I am not aware that there is evidence that would suggest that any one of the 10 or so modelling groups is significantly more skillful than the others. The ensemble mean is the average of them all.

       When will you get significant more warming? When the next El Nino cycle happens. If the climate response is more muted than expected, then that will cause some examination of the models. The strength of the aerosol forcing remains an uncertainty as do precise strength of cloud feedbacks.

       What is much easier to predict than surface temperature is total ocean heat content. However, we have only had detailed, accurate measurements since 2004. While OHC continues to climb (unlike the decline in mid-20th C or after Mt Punatoba), then it can be expected that surface temperatures will also rapidly climb in an El Nino.

34880. Robert Murphy at 11:03 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       That is, sure, once one understands that backwave radiation occurs resulting in IR being absorbed and turned into heat, yes, the hottest point is the sun itself, and all the other surfaces heat moves to are colder than that.

       And there's your answer as to why the greenhouse effect doesn't violate the 2nd Law, Matt.  You have to include the Sun's continuing contribution of energy.  If you don't everything else seems to violate the 2nd Law. 

34881. Tom Curtis at 10:15 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ @1440:

       "Let me try to put that another way: sure in the overall system, all the heat comes from the sun with the heat/temperature of the earth depending on both how quickly heat comes in and how quickly it goes out, so that slowing the rate of outflow raises the temperature. But to explain how this happens involves explaining how the hotter ocean surface can be heated by the cooler atmosphere, an apparent violation of the Second Law: this article 'explains' it only be getting the Second Law wrong, so that it really hasn't explained anything relevant."

       But the cold atmosphere does not warm the warmer ocean, and nor is their any apparent violation of the second law.  The second law, stated mathematically is that for a closed system:

       ΔS ≥ ∫δQ/T

       where S is the entropy, δQ is the incremental transfer of heat, and T is the temperature.

       Therefore to determine the entropy change we need to integrate over all incremental heat transfers.  In the case of the relationship between atmosphere and surface under the greenhouse effect, we need to integrate over all energy transfers between atmosphere and surface.  From the Fasullo and Trenberth, we have this summary of those transfers:

       

       Summing over all such transfers, we find that 356+80+17 =  453 W/M^2 is transfered from the surface to the atmosphere, while only 333 W/m^2 is transfered trom the atmosphere to the surface.  Integrated over all energy transfers from between surface and atmosphere, that is a net transfer of +120 W/m^2 from the warmer surface to the cooler atmosphere.  That transfer involves in increase in entropy proportional to the inverse of the reduction of temperature involved, ie, proportional ratio of surface to atmospheric temperatures.

       There is only an "appearance" of a violation of the 2nd law because people insist on considering the back radiation in complete isolation, ie, not as part of a system of transfers including those from the surface to the atmosphere.  If you intergrate all such transfers, as is required by the 2nd law, there is transparently no violation of the 2nd law involved.

34882. Donny at 09:39 AM on 15 August 2014
       Air pollution and climate change could mean 50% more people going hungry by 2050, new study finds
       

       Ma... I'm not sure if you missed some posts. ... since some were rerouted to more appropriate thread. ... but I was being told that the southern Canadian soil was no good because it had been scraped clean by glaciers.   I was also told it would take millions of years for the soil to recover. .. and I was given a reading assignment.  After doing my assignment the studies found that the soil in surrounding areas took 8000 years to recover.   And since the glaciers left that area 12000 years ago it was backing up what I had said earlier. <Snip>  Now for your second paragraph. ...

       Moderator Response:

       [PS] on very thin ice.

34883. MattJ at 09:21 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Hi, Tom-

       Thanks for your reply. For sure, Clausius was including such systems as you describe as "without some other change, connected therewith, occuring at the same time". He was even thinking primarily if not entirely of such systems. But how can we be sure that those are the only such changes he had in mind? I had the impression, based on discussions of the Second Law and its various forms in thermodynamics texts by Fermi, Feynman, Pauli and others, that the law, even in Clausius's form of it, covers a more general class of 'changes'. Thus, for example, Pauli paraphrases it as being equivalent to saying "heat conduction is irreversible". But the concepts of irreversibility and reversibility are more general than providing heat or work from outside, as in your refrigerator example. If when you go around the cycle, some thermodynamic variable must be different from the beginning when you get back, the process is irreversible, a change has occurred. It is not just the two thermodynamic variable heat and work that are under consideration.

       I also have to point out that I am not assuming "that the 'warming' of the Earth by greenhouse gases is analogous to the refrigerator case." Rather, I am pointing out that even when you say that it is based on "the  far simpler case of decreasing the efficiency of heat transfer outwards from a body warmed by a still warmer source", you are still leaving something out.

       That is, sure, once one understands that backwave radiation occurs resulting in IR being absorbed and turned into heat, yes, the hottest point is the sun itself, and all the other surfaces heat moves to are colder than that. But there is still the case of the cold atmosphere transfering heat to the warm surface to accomplish that "decrease of efficiency of transfer". Explaining that event's consistency with the Second Law is what is left out.

       Let me try to put that another way: sure in the overall system, all the heat comes from the sun with the heat/temperature of the earth depending on both how quickly heat comes in and how quickly it goes out, so that slowing the rate of outflow raises the temperature. But to explain how this happens involves explaining how the hotter ocean surface can be heated by the cooler atmosphere, an <b>apparent</b> violation of the Second Law: this article 'explains' it only be getting the Second Law wrong, so that it really hasn't explained anything relevant.

       If you really think Clausius' statement was meant to apply only in the context of heat engines and closed cycles, then it is useless to use his statement of the Second Law in this article, since, as you yourself point out, the analogy of a refrigerator (a heat engine of a particular sort) and the climate system is not very good, and can be quite misleading. The article should then use a completely different formulation, one that has been proved to generalize to the climate system, such as "in an isolated system, entropy is non-decreasing". But this particular option has its own difficulties, I think I understand why the author chose not to use it.

       Finally, concerning Phil's point. Yes, it was mentioned, but only later, and the author did not even seem to notice that he was contradicting himself, putting an unnecessary burden on the reader to resolve the contradiction, all still without a clear and correct statement of the law. Good expository prose does not do this: you get the statement exactly right the first time, and then explain as necessary the technical or otherwise surprising sense of the expressions used. Or you use a special case as a stepping stone to the final, full generalization. But even the appearance of self-contradiction defeats the purpose of the article — and creates a lot of room for the quibbling and carping we saw in 1400 posts.

       Not to mention there is still this crippling problem of the word 'generally' being used in the alleged statement of Clausius' form: no law of physics has such weasel words as 'generally', that makes the 'law' useless for generalization. No wonder Clausius himself never said that!

34884. PluviAL at 09:12 AM on 15 August 2014
       Global warming is moistening the atmosphere
       

       Check! Steve: However, the estimates for Antarctic contributions are less than clear. It could be that more of the sea level rise is from Arctic changes, in which case Antarctica might be a neutral to date, or even increasing. Links to evidence would be most interesting now. My intuitive fear is that Antarctica can contribute more either way than we are estimating. I can see West Antarctica contributing water, and East Antarctica absorbing it in big numbers; we just don't know.  

       One mm is not insignificant. The spheroid will adjust, as per GIA, rebound, you point out. For perspective, 10 inches is equal to the mass of 3500 three gorges dams (TGDs). Ten inches would be historical for Antarctica, but we are in geologically historical times.

       From my work on Pluvinergy, rhythmic GIA over millennia is a better candidate for tectonic plate movement motivation than liquid core circulation. Sorry, my work is all conjectural, but it is fun to think about, and frankly, it is a lot more convincing than conventional theory. PDF for the argument available if anyone is interested.

34885. Tom Curtis at 08:10 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ, the exceptions that Clausius allows for with his clause "without some other change, connected therewith, occurring at the same time" covers situations such as those found in refridgerators, in which heat is pumped from a colder interior to a warmer exterior, but only at the expense of pumping additional heat from a still warmer furnace (via power generation) to drive the process with a net increase in entropy for the entire process.  What you are missing is that the "warming" of the Earth by greenhouse gases is not analogous to that case.  Rather, it is analogous to the far simpler case of decreasing the efficiency of heat transfer outwards from a body warmed by a still warmer source.  Therefore, the exception is not involved.  Including a more explicit statement of the exception (more explicit because it is mentioned in the OP as noted by Phil) would therefore in no way help decrease scientific confusion about the greenhouse effect and thermodynamics.  Rather, trying to explain the greenhouse effect by analogy to refrigerators will increase that confusion.

34886. Phil at 06:18 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ's original request:

       Far better would be to use Clausius's own translation of his statement of the law: "Heat can never pass from a colder to a warmer body without some other change, connected therewith, occurring at the same time."

       is adequetly met by the word "spontaneously" in the OP version.

        

       but I would like to believe that a lot of the thrashing in the discussions attached to it could have been avoided if Skeptical Science would edit the article to make the correction

       In this I think you are naive; G&T's misformulation was too attractive for climate change deniers to resist, and they have continued to try and make it stick no matter how the 2nd Law was formulated.

       My own observation on the ensuing exchanges is that MattJ appears terribly confused about the distinction between energy and heat transfer; he should get that straight first.

34887. Dikran Marsupial at 05:46 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MA Roger, the point I was heading towards was that if photons from B that are abosorbed by A do transfer heat energy from a cooler object to a warmer one, then for MattJ's interpretation of the second law to be obeyed, there must be "some other change, connected therewith, occurring at the same time" and I was going to ask what it was.

       Of course if you adopt the modern statistical intepretation, there is no need to find the "some other change" as the second law only applies to the net transfer of heat, and there is no problem. The reason why we don't need to explain why it doesn't violate the second law of thermodynamics is because it is not precluded by more modern interpretations of the second law in the first place.

       I suspect the problem is that Clausius would have been easily able to measure temperatures of objects (and hence the net transfer), but how would he be able to detect the fact that the radiation is bi-directional between the objects?   Not too surprising then that he didn't make the distinction between transfer of heat and net transfer.

       The funny thing is the Science of Doom page gives exactly the same definition of Clausius' second law as the SkS page does.

       Anyway, MattJ has exhausted my patience, some people are fundamentally unable to see any point of view other than their own, and being unwilling to engage in a thought experiment designed to highlight where the disagreement lies suggests that they don't want to see any point of view other than their own.  This is a pity, as if  MattJ were right, it would be the most efficient way of demonstrating it.

34888. shoyemore at 05:42 AM on 15 August 2014
       2014 SkS Weekly News Roundup #33A
       

       I once amused myself with a fantasy future where every adult inhabitant of planet Earth has to "cultivate" an artificial "tree" that removes over time the amount of CO2 corresponding to that person's cumulative carbon footprint, maybe more in this century.

       If you think of paying a tax instead, there you have carbon taxes, in a way.

       The ant thing is interesting, though. Our new insect masters, turned into our saviours?

34889. MA Rodger at 05:11 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Dikran Marsupial @1434.

        

       You might find the comment @1435 a bit odd as you are, I think, confused by the comment @1433. The implication you make from the beginning of the final paragraph is contrary to the less ambiguous statements later in that paragraph. "...I already made it clear that I do undestand that the energy transfer you refer to is real. But simply acknowledging that it takes place does not address the issue: how can it take place without violating the Second Law?"
       MattJ is saying that photons do really pass from B to A but in so doing the 2nd Law of Thermodynamics is violated and this phenomenon thus requires explanation.

       Goodness!! It appears the 2nd Law of Thermodynamics is breached!!!

34890. MattJ at 04:58 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Dikran-

       Also, simply answering "since you are still requiring radiating CO2 molecules in a -20C stratosphere to heat up an ocean layer that is on average above +20C" with "I pointed out this is not the case is not helpful. Which part of it do you disagree with? Are you going to claim there is no LWIR coming from the stratosphere? Or that the stratosphere is warmer than the ocean surface? Even if the backradiation were mostly coming from the troposphere, it would still be going from cooler to warmer, yet transfering heat to the warmer ocean surface. The only difference is that the temperature difference is not as dramatic. But it is still there, and with the inconvenient sign.

       Now glancing back through the comments on this article, I noticed some tried to explain this by saying that the Second Law applies only to a closed system, or to "net heat". But Clausius never made a distinction between 'heat' and "net heat". And in the statement of the Second Law itself, he does not state any restriction to "closed systems" (but since he was speaking in the context of heat engines, one can make a case for that). So one must either prove that Clausius's statement either appies only to closed systems, generalizes to "net heat" or use a more modern form of the Second Law that is already known to apply to "net heat". Or take the Science of Doom approach, which as I already mentioned, works, but is awfully indirect; it is difficult to use in discussion with laymen or skeptics because of the long winding path through Kirchoff and Stefan-Boltzmann.

       But this Skeptical Science article takes none of these routes; it doesn't even get the statement of the Second Law correct. That is a serious shortcoming.

       Moderator Response:

       [JH] You are now skating on the thin ice of escessive repetition which is prohibited by the SkS Comments Policy. Please read the policy and adhere to it.

34891. Dikran Marsupial at 04:51 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ wrote "but then you immediately switched to talking about something else" no, as I said it was a metaphor to help you to understand the issue.  It is a shame that you did not engage with it.

       "Nor are you addressing the issue by asking about photons" you assume you understand the point I was making, which evidently you do not.  The fact that you refuse to answer the question suggests to me that you are not willing to have your argument put to the test, and therefore should not be surprised if you are not taken seriously.

       As it happens, for radiative transfer, it is exactly what happens to the photons and energy they carry that is important.

       I am always amazed how rare it is in discussions of climate change for people to be willing to answer simple direct questions and will go to such great lengths to avoid doing so!

34892. wili at 04:48 AM on 15 August 2014
       2014 SkS Weekly News Roundup #33A
       

       I'm not sure if SkS prefers to steer clear of reporting on specific extreme weather events (I can imagine that could become rather overwhelming these days), but there have been some pretty amazing downpours recently in Detroit and in the US northeast:thinkprogress.org/climate/2014/08/13/3470759/flooding-downpours-climate/ www.climatecentral.org/news/10-images-explain-northeast-flooding-17895

       (Did I do it right, this time?)

       Moderator Response:

       [JH] Yes, you activated the link correctly. You can also embed a link into the title of an article which is preferable where appropriate. 

34893. MattJ at 04:18 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Dikran-

       Yes, you did "point out that is not the case", but then you immediately switched to talking about something else, the several heat transfers that <b>are</b> in the direction of decreasing temperature, without addressing the real issue. That is why I asked you to "read what I actually wrote".

       Nor are you addressing the issue by asking about photons. The question is not "do photons take energy away from B and add it to A". The question is how this can happen without violating the Second Law. You should have not even asked the question not only for this reason, but because I already made it clear that I do undestand that the energy transfer you refer to is real. But simply acknowledging that it takes place does not address the issue: how can it take place without violating the Second Law?

34894. wili at 04:16 AM on 15 August 2014
       Air pollution and climate change could mean 50% more people going hungry by 2050, new study finds
       

       Thanks, Bob.

34895. wili at 04:09 AM on 15 August 2014
       Global warming is moistening the atmosphere
       

       Thanks, Steve. If you wouldn't mind sharing any links you found useful, I would be even further in your debt.

34896. Dikran Marsupial at 03:50 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       MattJ wrote"Please read what I actually wrote"

       I did, you wrote "since you are still requiring radiating CO2 molecules in a -20C stratosphere to heat up an ocean layer that is on average above +20C" and I pointed out that is not the case.  A blanket is just a useful metaphor I introduced to illustrate why that is not necessarily the case.  Now it seems the fastest way to reach agreement is by consideration of the thought experiment.

       Now you agree that body B emits photons that are absorbed by A.  Do you agree that this photon takes away some energy from B and adds it to A?  yes or no, if no, explain why.

34897. Chris G at 03:28 AM on 15 August 2014
       New study finds fringe global warming contrarians get disproportionate media attention
       

       Call me cynical, but I don't think the media outlets seek any sort of balance; they simply seek to sell advertisements while telling their stories.  Controversy makes for more interesting stories; so, they seek controversy.

       If they simply tell people there is no real controversy, these are the facts, then they loose market share to the agencies telling a more interesting story.

34898. Stephen Baines at 03:19 AM on 15 August 2014
       2014 SkS Weekly News Roundup #32A
       

       We just had an extraordinary event here on Long Island in NY.  Islip airport reported getting no less than 13.5 inches of rain (more than 34cm) in a single day, almost matching the record for the entire month of August and easily surpassing the state 24h precipitation record from hurricane Irene in the Catskills (11.8").  Incredibly, almost 10 inches (25cm) fell within two hours, between 6Am and 8AM.  

       Besides flooding, we now have beach closures, too.  We have combined sewage overflow systems in many places around here, especially NYC. When it rains heavily like this the sewage treatment plants get overwhelmed and raw sewage gets dumped directly into the rivers, bays and ocean.  So not only do we have to deal with the direct effects of flooding, but also the indirect effects on water quality and knock-on hits to human health and the economy.  It will be extrememly expensive to fix our sewage system so such events won't cause significant water quality crises in the future.

34899. MattJ at 03:16 AM on 15 August 2014
       2nd law of thermodynamics contradicts greenhouse theory
       

       Dirkan-

       Please read what I actually wrote and respond to that instead of rebutting a climate-denial argument I never used or supported. I am not talking about nor implying that "a blanket heat up a warmer body that is under the blanket". Unlike certain denialists, I understand that the heat transfers in the blanket example are all from higher temperature to lower, so that there is no need to invoke the "without some other change" clause in Clausius's statement of it. Nor do I doubt that in your black body example, both objects emit photons absorbed  by the other.

       I thought I made that clear when I said that " it [radiative heat transfer from cooler to hotter] is still a violation of the "imaginary second law", but not of the law as Clausius really stated it".

       Rather, the point I am trying to make is that different from that. Actually, I am trying to make three points: 1) the statement of the Second Law attributed to Clausius in the article is incorrect: it is not what Clausius said, nor is it even correct 2) you simply cannot build a correct scientific explanation/argument on an incorrect version of one of the fundamental laws 3) partly because of this mis-statement, the article has <b>not</b> explained why the cold CO2 in the stratosphere can transfer heat to the warmer earth and ocean surface without violating the Second Law.

       There was a good article on ScienceOfDoom that I always have trouble findiing when I look for it, it did explain why this transfer can take place — but only by referring to Kirchoff's Law and the Stefan-Boltzmann Law, pointing out that since these law were themselves derived from the Second Law, the results must be consistent with it.

       This approach is sound, it is correct, but it is awfully indirect. And it too relied on getting the statement of the Second Law correct, which this Skeptical Science article does NOT do.

       That is why I say that as a bare minimum, the article should correct the Clausisus quote and state the Second Law correctly. But it would be so much better if in addition to this, it can directly state what the "some other change" is when cold GHGs manage to transfer heat to the warmer thin surface layer of the ocean.

34900. Stephen Baines at 02:53 AM on 15 August 2014
       Global warming is moistening the atmosphere
       

       PluviAL

       The link between Antarctic sea ice and land ice is nebulous as far as I know from the literature I have seen.  The two things seem to be controlled by different things.  See the relevant posts here.

       That same post indicates that, despite the apparent increase in water vapor, Antarctica appears to have been a net conrtibutor to global sea level — i.e., the melting effects are outstripping the possible increases in precipitation.

       There could be seismic implication of sudden retreat of land glaciers, just as we are still seeing isostatic rebound from the retreat of the last glaciation.  Ice accumulation is pretty slow however, so we're not likely to see huge effects from accumulation of snow.  1mm of ice on top of miles of ice already there will be barely noticeable at depth.

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