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Tom Curtis at 08:28 AM on 18 August 20142nd law of thermodynamics contradicts greenhouse theory
MattJ @1468-70:
1) We have established that Clausius' first statement of the 2nd Law, as translated into English was:
"[The] general deportment of heat [is that it] everywhere exhibits the tendency to annul differences of temperature, and therefore to pass from a warmer body to a cold one."
That was glossed by Clausius as:
"Heat cannot of itself pass from a colder to a warmer body"
The original purported quotation sourced from wikipedia and appearing in the OP is:
"Heat generally cannot flow spontaneously from a material at lower temperature to a material at higher temperature."
It mashes the two together, taking glossing "general deportment of heat" from the body of the text as generally, and glossing "of itself" in the footnote as "spontaneiously". Both glosses are transparently reasonable, ie, they fairly present the information content of the phrases they gloss. Presented as a summary of Clausius' first statement of the principle (rather than a direct quotation), it is therefore wholly unobjectionable. If you have a problem with the use of the word "generally", take it up with Clausius.
2) As already noted, I would prefer the use of either of the two more considered forms of Clausius statement, and as direct quotations. The word "generally" does not appear in either, so that should satisfy you.
3) As shown in my post @1444, the heat transfer processes between surface and atmosphere are not changed by the absence or presence of sunlight in the short term. Therefore they do not involve one of the changes which are irreversible except by supplying the heat deficit from warm to cold of which Clausius was talking about in the footnotes.
It is compensated by the direct flow of a greater quantity of heat from the warmer surface to the cooler atmosphere. That is the other case of "compensation" that Clausius discusses and does not involve the Sun in any way except in replenishing the heat thus lost by the surface. Discussing the Sun as compensating the supposed reverse flow of heat merely confuses the issue for not such net reverse flow occurs, and hence no such compensatory role is called for. (As stated initially, this case is quite different to that of refrigerators, where a compensatory change in pressure of the coolant is required.)
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DSL at 07:46 AM on 18 August 20142nd law of thermodynamics contradicts greenhouse theory
I generally disagree with you, MattJ, but only because I'm trying to get this thread to 1500 comments. At that point, it will be taken out back and shot (and buried in an unpublished location).
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MattJ at 07:38 AM on 18 August 20142nd law of thermodynamics contradicts greenhouse theory
@1452
""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."
I am genuinely surpised at your interpretation of the word 'generally'. I would have thought English is nor your native language. Either that, or you are the one who is 'digging' and engaging in pedantry.
No, the only reasonble interpretation of the word 'generally' here is to make the whole sentence a generalization, which may have exceptions. But this in turn weakens the law to the point of uselessness, which is exactly why Clausius did not use the word 'generally' in <b>any</b> of his formulations. Not even in the footnote you provided. Nor is it used in any of the valid restatements of the law, both old and modern.
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MattJ at 07:28 AM on 18 August 20142nd law of thermodynamics contradicts greenhouse theory
@1466 & @1464
That is, as Dikran said, good detective work. But I am still amazed that you can claim, "I need only add that the formulation given in the OP is certainly a good paraphrase of the last formulation quoted from Clausius. Therefore there is nothing wrong with it except for the point that paraphrases should not be presented as quotations."
That 'formulation' still has the disastrous interpolation, 'generally'. That weakens the law to the point of total uselessness. It accomplishes nothing and destroys everything. Even just ripping out that one word would improve the original article by a lot.
Remove that one word! That is all I ask! (though, I would also like direct quotes to be real direct quotes...)
I should also point out that at no time did I accuse SkS of dishonesty for making this mistaken statement of the law. But I cannot see it as anything other than negligence that it has gone uncorrected for so long, even after comment #955 pointed it out way back in 2011.
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MattJ at 07:14 AM on 18 August 20142nd law of thermodynamics contradicts greenhouse theory
@1446
Dikran- Thanks for finding the link. I do need to point out, however, that when I right-clicked on the link labeled "Google Books", I got a broken URL. It was not hard to edit though: once I removed everything before "books.google.co", it worked (people using other browsers might have to insert/omit "http://" or "www.").
Now that I have read that note, I consider it more reasonable than I did before, to consider using his alternative statement of the same law "an uncompensated transmission of heat from a colder to a warmer body can never occur" and allow considering the sun's input of energy as such 'compensation'.
It still sounds odd to consider the sun's energy input 'compensation', we would not normally use the term that way nowadays, but as I read the footnote, I see he is using the term 'compensation' that generally. For he does say it expresses the same idea as "by itself", and we all agree that the heat transfer from colder CO2 to warmer ocean thin surface layer is ultimately driven by the energy input from the sun, it is not "taking place 'by itself'".
This has been a longer detour into the historical development of thermodynamics than any of us hoped for, but it does throw light on why the meme Science of Doom calls "the imaginary second law" is so persistent. Few thermodynamics courses at any level, even college level physics and engineering, are willing to take the time for such detours and show where misunderstandings of older thermodynamics terms and concepts still trip people up.
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billthefrog at 19:00 PM on 17 August 2014Climate scientists dub this year’s El Niño “a real enigma”
So, should we now refer to the phenomenon as an el Nigma?
(groan)
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Bart Verheggen at 07:42 AM on 17 August 2014Survey confirms scientific consensus on human-caused global warming
rkrolph,
I don't think that's quite true. Broadly agreeing with a dominant role of GHG in recent warming doesn't necessarily translate in being able to -or feeling comfortable to- put a relatively precise percentage range on it. In this case, choosing between the 3 categories (51-75; 76-100; >100%) that are all consistent with at least the most well known attribution statement. Because of the difficulty in choosing between these categories, many decided to fill out 'unknown' or 'don't know'. In many cases this can imo be interpreted as "we or I don't know the answer to that question to the level of precision that the answer options imply". An important argument for this interpretation is the comparison with the answers to Q3.
I don't think the answers to such a survey would be materially different a year from now. A year is a very short time in terms of scientific progress. Plus, the reasons as outlined above will still be valid, even as even more scientists may agree with the IPCC position.
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Dikran Marsupial at 05:07 AM on 17 August 20142nd law of thermodynamics contradicts greenhouse theory
Cheers Tom, I suspect you are right on the source, good detective work!
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Tom Curtis at 01:20 AM on 17 August 20142nd law of thermodynamics contradicts greenhouse theory
Dikran @1465, following up I have found the major revision of the wikipedia page on thermodynamics which eliminated the form of the statement quoted in the OP above, and replaced it with another version, which has since in turn been replaced. The original replacement took place on Oct 11th, 2010, with prior versions of the article having the quote in the OP. Evidently, therefore, the OP took its quote from the wikipedia page to which it linked. If it is a misquote, it is then entirely inadvertent as regards SkS. The original version on wikipedia may also explain the frequent occurence of that version on the web.
With regards to books, google books shows just five books containing that version of the quote. Of those, it shows the relevant contents of just three recent (2011 to 2013) textbooks, the former on "The Energy Problem", and the seond on thermodynamics, and the third being Farmer and Cook (2013). The earlier books are one from 2010 by Lawrence Soloman discussing "The Deniers", and one from 1992 by Richard Lindzen. Unfortunately without the text it is not possible to determine whether Lindzen attributes the version of the 2nd Law to Clausius, or whether he presents it as a quote.
Of the five, the most interesting is Stein and Powers (2011), which attributes the quote to "Rudolf Clausius' paper in 1850" (p27). In fact Clausius' talk to the Academy of Berlin in 150 was published in two parts in Pogendorff's Annalen, the first starting on page 368, and the second on page 500. These were translated in 1851, and included as the first memoir in the first edition of the "Mechanical Theory of Heat".
The closest formulation I can find in Clausius 1850 occurs on page 45 of the English first edition of "Mechanical Theory", and page 503 in the Annalen. In English it reads:
"Hence by repeating both alternating processes, without expenditure of force or other alteration whatever, any quantity of heat might be transmitted from a cold body to a warm one; and this contradicts the general deportment of heat, which everywhere exhibits the tendency to annul differences of temperature, and therefore to pass from a warmer body to a cold one."
The relevant principle is, of course, stated in the second part of the sentence. While the quote given in the OP is a good, if abbreviate, paraphrase of that sentence, it is also clearly not direct quotation. Interestingly, in the "Mechanical Theory" a footnote dates 1864 again glosses the principle stated in the body of the text as "... heat cannot of itself pass from a colder to a warmer body". That, or the alternative formulation, ie, that "A passage of heat from a colder to a hotter body cannot take place without compensation" have the strongest claim to represent Clausius' true formulation of the 2nd law (ie, the one he was happiest with on reflection).
Moving on: With misquotation, as with plagiarism, academic misconduct can exist in the absence of intent. That is why there are fairly strict academic rules about methods of quotation, which are always relaxed outside of strict academic contexts (and apparently always in the physical sciences). The strict rules are there to prevent inadvertent misquotation. One of those rules is that when you quote somebody indirectly by quoting somebody else quoting them you clearly indicate that so that any error can be attributed to the source that made the error. If you do not so attribute, you are considered as guilty of any error as if you yourself had made it.
In this case, however, clearly SkS misquoted here inadvertently by copying somebody elses "error". Further, they linked to their source and in a way that made it transperent that it was their source. At least, it made it transperent until the text of wikipedia was edited. Consequently no fault lies with the authors of the OP. Of course, that does not mean the text should not be updated with a correct quotation of an original source (or possibly rewritten in light of the other interesting material uncovered by this excercise.
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Dikran Marsupial at 20:58 PM on 16 August 20142nd law of thermodynamics contradicts greenhouse theory
Tom thanks for the adiditonal details, it does seem that Clasuius adopted the footnote for his second edition, as I mentioned in a previous post, but you have certainly clarified it further.
"I do not consider this a minor matter as misquotation is academic misconduct"
This is too strong a statement as it is only misconduct if done deliberately, if there is no intent to decieve, it is just an error and is not misconduct. I agree that it should be change if it turns out not to be a reasonable translation of something Clausius actually wrote, however this has not yet been established. It may be that his did write something along these lines in another work. Performing a google search suggests this exact wording does occur in other academic papers and books, so I doubt SkS are the first to make this error, if that is what it is. I am making enquiries...
However, in the light of my finding, I think it may be better just to rewrite the basic rebuttal from scratch as there is now a much more straightforward refutation of the myth based on Clausius' own understanding of his second law.
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rkrolph at 16:06 PM on 16 August 2014Survey confirms scientific consensus on human-caused global warming
Bart V.,
Thanks for the feedback. So, close to 20% of the AR4 authors were at least undetermined or unsure with respect to the precisely worded AR4 attribution statement. I think this survey was a great way to show where the consensus really is right now. I hope they do this survey in a year as I would expect the consensus should converge toward 100% as more evidence is gathered and the science improves. Unless, of course, legitimate contrarian evidence surfaces which would cause the numbers to go downward. This type of survey is a good way for non-experts to gauge that trend, without having to understand all the nuances of the scientific debate. That is important since it is the non-scientific public that needs to be convinced.
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Tom Curtis at 14:39 PM on 16 August 20142nd law of thermodynamics contradicts greenhouse theory
Dikran @1461, thankyou. In the second edition, Clausius attributes the formulation of the footnote in the first edition to himself (p78), and repeats much of the explanation from that footnote. In particular, he mentions the passage of heat from the colder to the hotter body, which is not prohibited, provided that a greater amount of heat flows in the opposite direction. His wording is:
"It is true that by such a process (as we have seen by going through the original cycle in the reverse direction) heat may be carried over from colder into a hotter body: our principle however declares that simultaneiously with this passage of heat from a colder to a hotter body there must either take place an opposite passage of heat from a hotter to a colder body, or else some change or other which has the special property that it is not reversible , except under the condition that it occasions, whether directly or indirectly, such an opposite passage of heat."
He concludes by formulating the 2nd law as:
"A passage of heat from a colder to a hotter body cannot take place without compensation."
That means in editing the OP to correct the misquotation, the author may use the above formulation, or that from the footnote which is now acknowledged by Clausius as his own. They need only include a link to the source either instead of or in addition to the link to wikipedia.
I need only add that the formulation given in the OP is certainly a good paraphrase of the last formulation quoted from Clausius. Therefore there is nothing wrong with it except for the point that paraphrases should not be presented as quotations.
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Tom Curtis at 13:57 PM on 16 August 20142nd law of thermodynamics contradicts greenhouse theory
Dikran @1453, while I still disagree that it is a cause of confusion, I do have to agree with Matt that the form of the 2nd law given in the article is not a quotation of Clausius, and is portrayed as such. If it was a paraphrase, it should not have been enclosed in inverted commas and should not have been indented (but may be higlighted in italics). By including quotation marks and indentation, the OP (whether intentional or not) has marked the statement as a quotation of Clausius, or (as it is in English) a fairly literal translation of Clausius. Further, if it is intended as a translation, it should be identical to the translation of the apparent source given for the quote, ie, the wikipedia article linked in the sentence introducing the quote.
As it happens, I have found a reproduction of the original Clausius article in german. From that it can be clearly seen that footnote was not included in that article, and hence it cannot be attributed to Clausius. On the other hand, Clausius did read and approve the proofs (footnote on page vii of the English translation). Therefore Clausius not only endorsed the translation of the principle given in that book, and quoted by wikipedia, but he also endorsed the explanation of the second law as given in that footnote. (He may even have written it, but we do not have proof of that and hence cannot attribute it to him.)
Turning to the actual words of Clausius,they were:
"es kann nie Wärme aus einem kälteren in einem wämeren Körper übergehen, wenn nicht gleichzeitig eine ander damit zussamenhängende Aenderung eintritt."
Google translate renders that as:
"it can never pass heat from a colder to a wämeren body, if not at the same time one other so zussamenhängende change occurs"
From that it appears that the rendition from the English version, and as given by wikipedia is fairly literal:
"Heat can never pass from a colder to a warmer body without some other change, connected therewith, occurring at the same time."
Given that, and the implied endorsement of the translation mentioned above, I think it is unreasonable to not take them as his words. The "quotation" in the original post, however, cannot be taken as anything but a loose paraphrase of those words, or a paraphrase of the English gloss from the footnote (which being originally published in English, requires no translation).
Given all this, the OP should be editted either to include the form of Clausius words as given in the English translation as quoted in wikipedia, or the text should be modified to indicate the law as actually given is a paraphrase, or the author's own phrasing of the law.
I do not consider this a minor matter as misquotation is academic misconduct, and therefore something SkS should never do except by accident, and in the later case the error should be corrected as soon as possible.
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PluviAL at 10:37 AM on 16 August 2014Global warming is moistening the atmosphere
Ian F: I got a real nice response from Snow and Ice Center. They detailed that in 2010 the loss was 134 Gt, 3 in 2011, and 23 in 2012, and that it is now losing 159 Gt per year.
It seems we need to keep good funding to our satellite and scientific talent. It is nice to have these measuring capabilities, and it would be a shame to let them degrade when they are most needed.
It is reassuring that we have people who study and understand these issues well. Although, this is a little frightening that Antarctica does not seem to be helping us, as much as guessed that it could. It seems intutiively, that it should be a moisture sink, rather than a net contributor.
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tcflood at 08:29 AM on 16 August 2014Global warming is moistening the atmosphere
One interesting side effect of this upper tropospheric moistening is that since the HCH bending vibrations of methane are overwhelmed by the HOH bend of water, the warming effects of increasing methane concentrations should be somewhat mitigated by higher humidity. Does anyone know if model projections show this effect?
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Phil at 07:56 AM on 16 August 20142nd law of thermodynamics contradicts greenhouse theory
MattJ @1450
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.
Unfortunately the word "generally" is there to cover Spontaneous endothermic reactions, These are reactions driven by a large increase in entropy, which can overcome a loss of enthalpy (and hence heat), and ensure that the change in Gibb free energy is still negative. This, of course, is to modify Clausius's words to cover the modern understanding of the second law of thermodynamics, which is only rigourously expressed mathematically (as Tom did @1441).
Thus Clausius's formulation of the 2nd law is actually incomplete as we now understand it. The author of the OP could either quote him directly and expose himself to the criticism that it was incomplete, or add the word "generally" to deal (albeit rather vaguely) with our current understanding.
I would also point out that you are (now) misrepresenting post 955, which does not object to the word "generally".
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Dikran Marsupial at 06:33 AM on 16 August 20142nd law of thermodynamics contradicts greenhouse theory
MattJ@1460 does that mean you now agree with me on my interpretation of the second law of thermodynamics only applying to the net transfer of heat, and hence there is no need to introduce the "other changes" clause?
BTW, the translation of the second edition suggests the footnote may not be an addition by the translator as the corresponding material is in the text of the second edition (translated by somebody else).
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MattJ at 06:30 AM on 16 August 20142nd law of thermodynamics contradicts greenhouse theory
@1446
Thank you, Dikran, for that excellent find! Sure, a footnote several times the length of the text may be intimidating, but that one was well worth reading And his formulation in that footnote, "...the warmer body never receives more heat from the colder one that it imparts to it." Is particularly good for silencing the skeptic's objection. Now the cold CO2 can impart heat to the warmer thin ocean layer as long as the latter gives more heat back.
I wish modern texts had footnotes that explained the meaning of the various terms as well as that one did. But that is an old-fashioned practice, rarely duplicated now. They try to do the same with sidebars with only mixed results.
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2nd law of thermodynamics contradicts greenhouse theory
MattJ - What I find most frustrating in these discussions are exactly statements like "you have heat going from cooler to hotter".
"Heating" in colloquial usage is an increase in net energy causing an increase in temperature. Energy goes from cool objects to warm objects (in fact, to all objects within the radiative view of that cool object), not heat, not by the common use of that term.
Energy goes from cooler to warmer objects, which add to the sum of energy going into that warm object, an increase of incoming energy - and hence the object must warm to radiate energy equal to incoming.
But the net flow of energy, heat, is still from the warm object to the cool one. Adding a cool object simply reduces that net energy transfer.
To be more precise, a cooler object will cause a warmer object (or one of any temperature) to increase in temperature if that cooler object adds >0 energy, if the cool object radiates/conducts/convects more energy than an absolute zero background. The starting point is an contribution of zero, anything warmer than that will add incoming energy to an object in view, increasing the input.
For some reason the fact that any radiating object represents a positive contribution to incoming energy gets somehow overlooked in these discussions.
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Dikran Marsupial at 06:21 AM on 16 August 20142nd law of thermodynamics contradicts greenhouse theory
"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".
or alternatively, you could just show them the pages in Clausius' book where it is carefully explained that this is O.K. as it is "compensated" by a greater flow of heat in the other direction. There is then no need to mention entropy.
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Bart Verheggen at 06:20 AM on 16 August 2014Survey 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.
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MattJ at 06:13 AM on 16 August 20142nd 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.
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Dikran Marsupial at 05:59 AM on 16 August 20142nd 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.
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MattJ at 05:43 AM on 16 August 20142nd 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.
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Dikran Marsupial at 05:38 AM on 16 August 20142nd 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.
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Dikran Marsupial at 05:36 AM on 16 August 20142nd 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.
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Dikran Marsupial at 05:33 AM on 16 August 20142nd 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.
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MattJ at 05:32 AM on 16 August 20142nd 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?
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MattJ at 05:23 AM on 16 August 20142nd 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.
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MattJ at 05:16 AM on 16 August 20142nd 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.
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Harry Twinotter at 04:51 AM on 16 August 2014Climate 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=OverviewModerator Response:[JH] Link activated.
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TomR at 03:38 AM on 16 August 2014Climate 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.
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joeygoze9259 at 03:36 AM on 16 August 2014Climate 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.
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jetfuel at 01:54 AM on 16 August 2014Antarctica 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?
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Dikran Marsupial at 01:29 AM on 16 August 20142nd 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.
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PhilippeChantreau at 23:37 PM on 15 August 20142nd 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.
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DSL at 23:31 PM on 15 August 2014Global 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.
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CBDunkerson at 22:40 PM on 15 August 2014Global 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.
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Dikran Marsupial at 21:25 PM on 15 August 20142nd 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.
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BojanD at 20:38 PM on 15 August 2014Error 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%.
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Phil at 19:21 PM on 15 August 20142nd 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.
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scaddenp at 18:51 PM on 15 August 2014Air 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.
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jamesshaffer at 18:38 PM on 15 August 2014New 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.
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Tom Curtis at 15:32 PM on 15 August 20142nd 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.
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denisaf at 13:21 PM on 15 August 2014Global 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.
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MattJ at 13:19 PM on 15 August 20142nd 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".
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Ian Forrester at 12:49 PM on 15 August 2014Global 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 ."
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scaddenp at 11:39 AM on 15 August 2014Facts can convince conservatives about global warming – sometimes
I have also responded to your model question in the appropriate place.
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scaddenp at 11:37 AM on 15 August 2014Models 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.
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Robert Murphy at 11:03 AM on 15 August 20142nd 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.
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