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mistermack at 03:01 AM on 27 October 2010Models are unreliable
Jmurphy, do you really believe that the models are just constructed from the laws of physics? Someone sat down with a physics textbook and developed the current models? Without peeking at the previous data even once? "based on" is a meaningless phrase here.Moderator Response: Look in the green box at the bottom of this Argument--the box labeled "Further Reading." Click those links. You will learn how physics is used in the models, and how and to what degree observations are used. -
The 2nd law of thermodynamics and the greenhouse effect
BP, No, I didn't have anything specific in mind. My issue is that you implied a few times that the most likely scenario following a change in the climate landscape would be a return to an entropy maximum with a total rate of entropy production exactly equal to the previous local maximum. I don't see why you would get the impression that such a change would be the most likely scenario. In fact, given that the unknown future maximum could be either lower or higher to some degree, it is extremely unlikely that the new maximum will just happen to be identical to the previous maximum (or any specific value). You have repeated a few times that - given the MEP principle - a negative feedback is likely. I don't see any basis for this implication. MEP alone neither supports nor contradicts AGW. To suggest that MEP predicts a negative feedback is to assume that the climate will be able to arrange itself in a way that a) increases the earth's entropy production and b) is impossible today or would not lead to entropy increase today. In other words, your argument is in the exact same place it was before invoking MEP; you are proposing that some as yet unknown or misunderstood mechanism may kick into effect that will negate or diminish GW. All you are really doing is restating that hypothesis in terms of entropy and MEP rather than thermodynamics. That doesn't change the fact that we need some evidence before assuming such a mechanism, or even implying that such a mechanism is likely to exist. In fact, MEP reduces the probability that such a mechanism exists, since it adds an additional constraint to the nature of this mechanism, i.e. it is impossible today or would not lead to entropy increase today. -
The 2nd law of thermodynamics and the greenhouse effect
I'm not terribly worried about the skeptical blogs, either - they tend to be self-selecting for the already convinced. But the amount of general press this horrid (and yes, laughable) article got made it significant enough to respond to. -
JMurphy at 02:50 AM on 27 October 2010Models are unreliable
mistermack, are you suggesting that the hypothetical model for the Kentucky Derby would be based on the laws of physics ? -
mistermack at 02:47 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
Well, that' my problem then. I don't know any sceptical blogs. I'm sure they contain some crazy stuff. If I saw this suggestion, about the second law, my initial reaction is that it's laughable, and not worth answering. -
The 2nd law of thermodynamics and the greenhouse effect
mistermack - This particular skeptical argument was hardly hidden away somewhere. I believe that it was discussed on almost every climate blog for about 10 months over the last year. That includes ScienceOfDoom, Deltoid, ClimateRealists, bunches of others. It also made it into any number of news outlets as mentioned by skeptic columnists. Try googling the authors and see. It didn't die down as a heavily promoted anti-AGW argument until several rebuttals appeared (including a peer reviewed one, Halpern 2010, which I believe was about the only citation for the Gerlich article). This particular argument against global warming was idiotic, but hardly a strawman, given the attention paid to it on the skeptic front. -
archiesteel at 02:40 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
@mistermack: "Find a pathetic argument, hidden away somewhere, and debunk it. That's a strawman tactic to me." We don't "find" that pathetic argument, it is brought up by some contrarians. I would rather never hear about it again. A strawman is attributing to someone an exaggerated version of their position that is easy to debunk. That's not the case here - some (not all) contrarians really do argue this. Note that nowhere did anyone here suggest that *all* skeptics believe this. However, it is undeniable that some do, and as the goal of this site is to list *all* arguments used by those challenging AGW theory, then this one must be included as well. -
archiesteel at 02:24 AM on 27 October 2010Models are unreliable
@mistermack: false analogy. If you don't put your money on the horse (i.e. you don't trust the models), you are unaffected whether it wins or loses. Your life goes on as normal. If don't "put money" on AGW (i.e. disbelieve the experts) and it turns out to be true - as the body of science strongly suggests - then you'll be affected. A better analogy would be if someone kidnapped a loved one, told you to pick the next Kentucky Derby winner, and warned you they'll kill the hostage if you pick the loser. Which horse would you pick then? The favorite (i.e. the one the experts say has a better chance of winning than the others according to odds calculations), or a long shot that experts say is unlikely to win? -
mistermack at 02:23 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
I wrote "I've never read it till now". I didn't think it had never been written, just not widely argued, or taken seriously. To qualify as being a strawman, it doesn't have to be brand new. You can find strawmen, you don't have to invent them. Find a pathetic argument, hidden away somewhere, and debunk it. That's a strawman tactic to me. -
archiesteel at 02:14 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
@mistermack: I myself have heard that argument during debates against people opposed to AGW theory. Can we put you on record as agreeing that the greenhouse effect *doesn't* violate the 2nd law of thermodynamics? It'd be nice for us to agree for a change. :-) -
Berényi Péter at 02:11 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
#69 mistermack at 00:34 AM on 27 October, 2010 Seems like a great big straw-man to me Here is the paper nealjking says went down in flames. International Journal of Modern Physics B (IJMPB) Condensed Matter Physics; Statistical Physics; Applied Physics Volume: 23, Issue: 3(2009) pp. 275-364 DOI: 10.1142/S021797920904984X FALSIFICATION OF THE ATMOSPHERIC CO2 GREENHOUSE EFFECTS WITHIN THE FRAME OF PHYSICS GERHARD GERLICH & RALF D. TSCHEUSCHNER -
mistermack at 02:10 AM on 27 October 2010Models are unreliable
Suppose they took the world's best computers, and the best modellers, and worked on the last twenty years Kentucky Derby results and form. Eventually they produce a model that predicted them all. Would you sell your house, and put the money on the same model's prediction for the next Kentucky Derby? -
DSL at 01:14 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
You haven't read much, then, have you mistermack? It's a thread on almost every denialist site. Here's one. Also, your claim of (great big) straw man implies that you have an alternative theory to protect against such attacks. Is this true? Where is it? Or are you simply representing the denial-o-sphere as a (internally inconsistent) whole? -
nealjking at 01:13 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
#69, mistermack: Gerlich & Tscheuschner wrote a paper that claimed that. It got published, but the general consensus is that it went down in flames. -
JMurphy at 01:04 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
mistermack, you should spend some more time at Jennifer Marohasy's site, if you want to find out where that non-strawman came from. Or have a look at the 'Skeptic Links' at this link on Skeptical Science. You could have found that one yourself by searching... -
The 2nd law of thermodynamics and the greenhouse effect
mistermack - Google the horror that is "Gerlich and Tscheuschner". They claimed that the radiative greenhouse effect violated the 2nd law of thermodynamics. They were wrong, of course, and their physics were appalling. But their article, published as an editors choice (i.e. not peer-reviewed) in a low impact off-topic journal, got waved about by certain skeptics for quite some time. It was very sad... I shed some tears for the educational system during that time. On the plus side, a lot of people had a chance to learn some basic physics during the arguments, and some of the more competent scientific skeptics, such as Roy Spencer, weighed in on the side of reason and dismissed it. -
mistermack at 00:34 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
"Skeptics sometimes claim that the explanation for global warming contradicts the second law of thermodynamics." Do they? I've never ever read that till now. Seems like a great big straw-man to me.Moderator Response: Many of the posts appearing on the home page recently have been posted there to call attention to that same material having newly been created and added to the regular set of "Arguments." You can tell by reading to the end of the home page's post where you will see a green box which, in this case, states "This post is the Basic Version (written by Tony Wildish) of the skeptic argument 'The 2nd law of thermodynamics contradicts greenhouse theory'." Each of those regular Arguments begins with an orange box with a quote and link to a skeptic making that skeptic claim. -
Ken Lambert at 00:30 AM on 27 October 2010It's the sun
Gentlemen Regarding the numbers I am currently crunching (Ref #651)- could anyone point me to some historical data on Wate Vapor + Ice Albedo feedback - currently quoted by Dr Trenberth at +2.1W/sq.m in AD2005. I could assume linearity back to zero in AD1750 but this is a very significant component, and this could widely affect the result of the Total forcing sum. -
Waste heat vs greenhouse warming
Analogies and their issues; Analogies are fine when used to explain aspects of a complex system. They fail when you try to use them to disprove that complex system, because the analogy is not a 1-1 mapping. See a much more detailed posting here, motivated by similar logical issues earlier in this topic thread. I wouldn't bother to play the analogy game, CBD - that leads straight to this Bad Analogy error. If you want to disprove a theory or system, you have to do the work there, not in a made-up world whose parameters change with every reply. -
muoncounter at 00:27 AM on 27 October 2010Waste heat vs greenhouse warming
#336: "that energy being injected into the environment is having no impact, (instead of warming things, it hightails for the stars)" All energy injected into the environment does not hightail for the stars ... some of it is trapped (or at least stored temporarily) here in an atmosphere increasingly rich in GHGs. Of course, those same GHGs also trap some of the far larger supply of energy from the sun. But bottom line, RSVP is a warmist! -
The 2nd law of thermodynamics and the greenhouse effect
Berényi - I'll emphasize my primary point once more. To the extent (and this appears to be an interesting point of research) that MEP is a factor in climate dynamics, it's a factor not just in forcing deltas but in the state(s) prior to the forcing deltas. Therefore MEP is already part and parcel of the climate sensitivity to forcings. Not a new factor that will jump in, but an existing part of the system dynamics. That means that climate sensitivities to forcings still hold, that those measured 'black-box' sensitivities inherently factor in the MEP effects. -
muoncounter at 00:17 AM on 27 October 2010Measuring CO2 levels from the volcano at Mauna Loa
#13: "Do Mauna Loa and other stations measure the concentration of other greenhouse gases in the atmosphere?" Yes, although not all sites around the world measure all species. Look at NOAA's data viewer where you can select among CO2, CO, CH4, O3, SO2, NOx, etc. -
Berényi Péter at 22:01 PM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
#66 e at 18:35 PM on 26 October, 2010 is it not possible that the rearranged landscape consists of a lowered local peak, rather than a translational shift of the landscape? It is certainly possible, but I don't see a compelling reason it should be so. Even for infinitesimally small increases of baseline opacity the transformation the landscape suffers seems to be of some more general form than simple downscaling. But I have not done a full mathematical analysis of the situation yet, it's just an impression. Do you have anything specific in mind? BTW, as I'm peeking into the literature, I see a widespread misconception about MEP-related role of radiative transfer in the climate system in general and about Dewar 2003 specifically. Stephen Mobbs is even enumerating in a presentation among Dewar's results the following proposition: "MaxEnt is equivalent to maximising the mean entropy production rate <σ> due to internal material processes – not including radiation [emphasis mine]" Journal of Physics A: Mathematical and General 2003, Volume 36, Number 3, 631 doi: 10.1088/0305-4470/36/3/303 Information theory explanation of the fluctuation theorem, maximum entropy production and self-organized criticality in non-equilibrium stationary states Roderick Dewar What Dewar actually says is this: "For climate systems there is an additional contribution to σΓ from radiative heating at planetary temperatures, deriving from the internal energy component of Q in equations (9) and (12). This contribution is not taken into account in the purely material entropy production of equation (15), and is in fact ignored in applications of MaxEP to the climate [16, 17]. Again Jaynes’ procedure provides the rationale for ignoring this contribution – radiative heating is reversible and does not contribute to the number of paths W(Airr<λ>) in equation (24). To summarise, in applications of MaxEP to climate systems it is the irreversible, material entropy production that is maximised." It is said in the context of interpreting Paltridge's work on application of MEP on horizontal heat transport (advection) and he just tries to justify why radiation was ignored in that work. Indeed, as long as radiative heating is supposed to be reversible, it does not give a contribution to the number of paths. However, while it might have been a reasonable approximation for the specific problem Paltridge was interested in, it surely does not hold in general. In a semitransparent medium (like air) whenever radiative exchange occurs between two parcels at different temperatures, the process is irreversible and involves entropy production. It may be negligible at the center of CO2 absorption band (at 15 μm) where mean free path of IR photons is small and nearby locations are at almost the same temperature, but as we move to the wings or even to an atmospheric window with no absorption lines at all just the H2O continuum, parcels at vastly different temperatures can get into radiative contact (like hot (-50°C) Antarctic winter troposphere with cold (-80°C) surface). If one is interested in climatic effects or the radiative properties of CO2, ignoring radiation entropy is certainly the most foolish track to take. As soon as we stop treating clouds, snow cover or ocean color (induced by biological processes, determining light extinction with depth) as boundary conditions, but include them as variables in the climate system, entropy production associated with ASR (Absorbed Shortwave Radiation) also enters the game. -
CBDunkerson at 20:23 PM on 26 October 2010Waste heat vs greenhouse warming
RSVP, ok I'll play... now its a dam. So in the scenario you posit with the "narrow slot" the outflow of water is constrained... the inflow can increase without the outflow increasing in turn (until the water level rises so high that it overtops the dam). Please explain what mechanism you think exists which similarly constrains the outflow of energy from the Earth to a fixed amount. Also, decreasing the outflow by 100x is still going to cause the temperature to rise one hundred times faster than increasing the inflow by 1x. So we're still looking at AWH warming being an insignificant factor unless your unexplained mechanism for constraining radiation outflow is itself somehow immune from being blocked by greenhouse gases. So there you go. Your analogy can work. You just have to explain two little things which violate the laws of physics as we know them. -
The 2nd law of thermodynamics and the greenhouse effect
BP >If there is a maximum entropy production principle at work indeed, for a neutral feedback you need the same climate state to be found right at a peak on the rearranged landscape, which is extremely unlikely. Correct me if I'm missing something here: is it not possible that the rearranged landscape consists of a lowered local peak, rather than a translational shift of the landscape? In such a case, we would expect a neutral response since we would already be at the local peak. If so, is it not invalid to assume that neutral feedback is "extremely unlikely?" -
RSVP at 18:29 PM on 26 October 2010Waste heat vs greenhouse warming
CBDunkerson #340 You are correct about a lake with the topology you assume. In mine, the outflow is restricted through a narrow slot, and likely isnt too common in nature, but is possible. I should have said "dam", my bad. But now that you have taken up the point, it looks like there are two things to consider as far as the comparison with global warming. In the lake or dam, the rate of level change will depend on three things. How much water this new "spring" represents, the uptake capacity, and to what extent the outflow will increase as a result of an increase in height. This increase must be less than the source influx. This last factor seems to be key, and unless this is determined, I dont see how anyone can claim to be in a position of certainty. The question is really not whether it is accumulating. The question is how fast. All I am hearing is that radiation increases as the fourth power of temperature. If things were that simple, you wouldnt have to increase the size of an audio amp's cooling fins as a function of power rating. In the same way, the Earth's thermal radiation capacity is limited by the size of the Earth and any and all properties that affect its total emissivity. e #337 What I explain above applies in the same way to what you bring up here. You seem to have ignored the words "in a way that exactly compensated...", which implies a difference that accounts for energy that is "temporarily" being stored. And "temporary" really means "permanant" as long as the additional flux is present. -
Berényi Péter at 16:54 PM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
#63 KR at 13:28 PM on 26 October, 2010 Currently we are moving towards (but have not reached) an equilibrium - but a 'steady-state' system will still reach an entropy balance (dynamic equilibrium) where energies do not change I think you still don't get it. Here is a readable account on MEP (Maximum Entropy Production), SOC (Self-Organized Criticality), including toy models like Sandpile Avalanche Dynamics and FT (the Fluctuation Theorem). Non-equilibrium Thermodynamics and the Production of Entropy Understanding Complex Systems, 2005, 2005, 41-55 DOI: 10.1007/11672906_4 4 Maximum Entropy Production and Non-equilibrium Statistical Mechanics Roderick C. Dewar Critical systems' scaling behavior is well understood in physics. If the majority of climate scientists think climate is somehow different with a very special structure that invalidates general principles, they have to explicate this idea clearly, simple hand waving like in Ozawa 2003 would not suffice. -
Kooiti Masuda at 16:21 PM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
Concerning thermodynamics, we have several different levels of knowledge. 1. Equilibrium thermodynamics. We can compare two states of thermodynamic equilbrium of the same system, and tell in which direction spontaneous changes can occur. But this formulation cannot usually describe the processes of the changes which are non-equilibrium. 2. Local thermodynamic equilbrium. While the climate system as a whole is clearly not in a thermodynamic equilibrium, we can define thermondynamic quantities such as temperature in a certain spatial and temporal scale, which is much larger than individual molecules and individual collisions between molecules, but much smaller than the whole atmosphere. If we smooth out the microscopic variabilities, the thermodynamic quantities can be considered as functions of macroscopic space and time coordinates. (This condition does not hold in the upper atmosphere, but acceptable for the troposphere and the stratosphere.) 3. Formulation of non-equilibrium thermodynamics. We can describe the rate of change of entropy in the climate system or a certain subsytem of it as the sum of entropy exchange and entropy production. Entropy production must be positive. There is no other formal constraint at this level. 4. Dynamic steady states in the entropy balance. The climate system can be approximated as a steady-state system which exports as much entropy as is produced within it. The system may actually fluctuate around the steady state. If the external condition changes slowly, the state of the system will drift acoordingly, but it may still be be approximated as a steady state. If the external condition changes too fast, the state cannot be considered as steady. 5. The hypothesis of maximum entropy producition. Under a certain external condition, there is a range of approximately steady states which our system can take. Among them, the state which has the maximum rate (=quantity per unit time) of entropy production is likely to be realized. I think that the items 1 and 2 are shared by effectively all physical climate scientists, and that 3 and 4 are acceptable by the majority of them (though many of them do not conceive them by themselves), but that 5 is held just by a minority among them. -
Daniel Bailey at 14:01 PM on 26 October 2010Measuring CO2 levels from the volcano at Mauna Loa
Re: Agnostic (13) Whenever I have a question (and having an enquiring kinda mind, I have many [questions, not minds; multiple minds would be silly, wouldn't it? Shut up and let the man talk!]), I like to go straight to the source. In this case, the Earth System Research Laboratory that operates the Mauna Loa facility in question. There one would thus find a full panoply of measurements of various and sundry greenhouse gases in full regalia. But that's me. As far as your last question, given your earlier worthy comment on that subject, that would seem to be a rhetorical question. But yes, that would be the reaction of sensible people. Which is why our politicos in America will procrastinate until it's too late. Prevention is out the window. All we will be able to do is to adapt as best able. Asbestos underwear, anyone? The Yooper -
Albatross at 13:59 PM on 26 October 2010Irregular Climate podcast 13
I really enjoyed listening to this today whilst doing some number crunching Excellent (and comprehensive) job guys. -
Jerry at 13:39 PM on 26 October 2010Measuring CO2 levels from the volcano at Mauna Loa
I don't think the sea breeze has much of an effect on Mauna Loa. What does have a big effect is the inversion layer. From their website "MLO also protrudes through the strong marine temperature inversion layer present in the region. This inversion layer acts like a lid and keeps the lower local pollutants below the observatory." I am not an expert but I do live in the area. Often the lower level winds and the winds aloft are blowing different directions, which can make for interesting cloud watching. Jerry -
The 2nd law of thermodynamics and the greenhouse effect
Berényi - I would actually have to disagree about equilibrium states. If a constant input and sink of energy are maintained (sun and the 3 degree K of space), the climate will cycle around equilibrium based on the internal variance of weather. Currently we are moving towards (but have not reached) an equilibrium - but a 'steady-state' system will still reach an entropy balance (dynamic equilibrium) where energies do not change. As Riccardo stated, the MEP indicates the path taken towards equilibrium, or as I understand it entropic balance. That affects the speed of attaining equilibrium, not the final thermodynamic state. Re-reading Ozawa et al: they are indeed speaking of speed (delta) of entropy, not the final thermodynamic states. If you disagree, please point out the sections of the paper that indicate this. You have also not addressed my point here, that high entropy production if correct is already part of the climate sensitivity - it's already incorporated into our knowledge and models of climate behavior. -
Riduna at 11:08 AM on 26 October 2010Measuring CO2 levels from the volcano at Mauna Loa
Mauna Loa and other sampling sites provide an interesting record of increasing atmospheric CO2 but how much of it is the result of human activity (and how is that determined) and how much is from other sources? Global warming arises from the increased presence of greenhouse gases (CO2-e) in the atmosphere, CO2 being only of them. Do Mauna Loa and other stations measure the concentration of other greenhouse gases in the atmosphere? Measuring CO2 concentration only provides part of the picture. For example, as global temperatures rise melting permafrost and ice, methane is released from subsurface decaying material. When ocean water warms it is less able to absorb atmospheric CO2 and increases its release of that gas into the atmosphere. Are these effects identifiable and are they measured? When we talk of the importance of keeping the concentration of CO2 in the atmosphere to less than 450 ppm, should we not be stressing the importance of keeping the concentration of CO2-e in the atmosphere to less than 450 ppm?Moderator Response: Your questions are generally addressed in the following posts:
How do human CO2 emissions compare to natural CO2 emissions?
Water vapor is the most powerful greenhouse gas
What is methane's contribution to global warming? -
Berényi Péter at 10:33 AM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
#59 KR at 07:53 AM on 26 October, 2010 If Riccardo is correct, this means that the MEP principle you brought up has zero effect on the equilibrium temperature change for various forcings, only (if the MEP hypothesis is true) upon the speed (time lags) at which the climate moves there Wait, I can see a conceptual confusion here. The climate system is never in thermodynamic equilibrium, not even close to one and the MEP tells nothing about the path to be taken there either. It's in a steady state, which is a completely different thing altogether. In this state a pretty stable stream of energy flows through it, arriving as low entropy sunlight and (part of it) leaving as high entropy thermal IR radiation against the cosmic microwave background. So there is also a constant rate of entropy production. In fact it is not really constant, just a target value actual entropy production tends to fluctuate around in a scale invariant manner. It is much like sandpile avalanche dynamics in this respect. If you change the system by increasing baseline IR opacity of the atmosphere a bit, I have already shown you it decreases entropy production rate (along with increasing average surface temperature) if all else is held unchanged. You can depict it as a landscape defined over a phase space of climate states by the entropy production rate function. MEP means the climate state tends to linger around a peak. As soon as baseline IR opacity is increased by a small quantity, the landscape gets rearranged somewhat. If there is a maximum entropy production principle at work indeed, for a neutral feedback you need the same climate state to be found right at a peak on the rearranged landscape, which is extremely unlikely. All other positions would involve some negative feedback and there is no room for a positive one at all. Of course the MEP is only a local constraint, meaning all sufficiently small changes of the climate state relative to the actual one tend to decrease entropy production rate. It does not mean there are no higher peaks at all along the landscape, accessible only through deep valleys (that is, not accessible under normal circumstances). With an ever increasing baseline opacity of the atmosphere at some point the topological structure of attractors over this landscape may get rearranged (at which point, we have no idea), so as a previously inaccessible peak becomes accessible along a continuous path with an ever increasing entropy production rate (or at least it only needs to jump through shallow valleys). If this happens, a climate regime shift occurs, but it is a highly nonlinear process, inexpressible in the climate sensitivity formalism. It is not clear either if this new steady state would imply higher or lower average surface temperatures (or the same ones with some regional rearrangement). Unfortunately mainstream climate science failed to ask these questions so far, so for the time being we do not have a chance to get proper answers. -
Riccardo at 09:07 AM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
KR very much like the equilibrium state, i.e. that of maximum entropy, in statistical thermodynamics can be defined as the most probable state, the maximization of the entropy production rate may be thought as defining the most probable path toward equilibrium. I'm not an expert on non-equilibrium thermodynamics and I can't tell if the MEP path is always the fastest possible. In simple systems I guess it probably is, it's not obvious it will be so in general. -
Harald Korneliussen at 08:41 AM on 26 October 2010Irregular Climate podcast 13
Typo: Micheal => MichaelResponse: Fixed, thanks -
CBDunkerson at 08:14 AM on 26 October 2010Waste heat vs greenhouse warming
RSVP, back at 272 you wrote: "Imagine a lake whose level is seen to rise 3 inches in the course of 150 years due to a new spring breaking ground up stream." I couldn't "imagine" this because even the analogy breaks the laws of physics. So let's see if fixing it helps you see what we are saying. If a lake (i.e. the Earth's atmosphere) suddenly acquired a new source of incoming water (i.e. heat), such as the spring in your example (i.e. waste heat), it would NOT slowly increase in depth (i.e. temperature) over 150 years. The depth would increase almost immediately and then stop because the higher water level would allow more water to flow OUT of the lake as well. Once the new net outflow was equal to the new net inflow the new water level of the lake would then be set. How long the spring continues pouring in water is irrelevant... it doesn't lead to an ever increasing water level because when the inflow increases the outflow inherently must as well. Further, if the new inflow ever stopped or declined (i.e. we began producing less waste heat) the lake would quickly drop down to a lower level... the constant inflow is required just to MAINTAIN a small increase in the water level rather than producing a continually increasing level. Now, if you were to put sand bags blocking some of the streams leading out from the lake (i.e. decrease radiation outflow by increasing greenhouse gases) the lake would rise until the net outflow from the remaining streams, or possibly over the tops of the sandbags, again equaled the net inflow. The water level would then stay at that new height until the sandbags were removed. The inflow and outflow of water in a lake and energy in the atmosphere are pretty close corollaries... so long as you stick to actual physics for both. -
scaddenp at 07:54 AM on 26 October 2010Blaming global warming on the oceans - a basic rebuttal
Dan, since oceans cant generate heat, then heat from oceans cant be forcing only a mechanism. So the correct approach is do what you do, but plug in the real forcings instead. Already done of course, looks within Benestad & Schmidt -
The 2nd law of thermodynamics and the greenhouse effect
* state * -
The 2nd law of thermodynamics and the greenhouse effect
Riccardo - So, the MEP principle doesn't affect the thermodynamic end stateto, but simply says that systems will tend to move to that state as quickly as possible? Berényi - If Riccardo is correct, this means that the MEP principle you brought up has zero effect on the equilibrium temperature change for various forcings, only (if the MEP hypothesis is true) upon the speed (time lags) at which the climate moves there. -
Riccardo at 07:27 AM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
nealjking and indeed you can't. First, the MEP principle says other things than the 2nd law; it says that a system out of equilibrium will follow the path that maximises the entropy production rate. Note that it does not define the final equilibrium state, which (apart from metastable states which might occur) is still given by standard thermodynamics; it just tell us the path toward it. Second, it aspires to be a principle and hence it's not demonstrated; only time will tell if it really is a general principle or if it has a limited range of validity. It is a very interesting topic, whose consequences are yet to be unveiled. Unfortunately, it currently does not add much to our knowledge of the final fate of our planet, so neatly given by standard thermodynamics. -
RSVP at 07:06 AM on 26 October 2010Waste heat vs greenhouse warming
Bibliovermis #335 "... a well-established field of scientific endeavor is composed of grossly incompetent, corrupt individuals" This is a good point, and we would all be better off assuming good will on all sides. -
Daniel Bailey at 07:05 AM on 26 October 2010Why is Greenland's ice loss accelerating?
Stop the presses, this just in:Danish research scientist Sebastian Mernild of Los Alamos National Laboratory in the US told national daily newspaper Jyllands-Posten that his calculations show that 540 cubic kilometres of inland ice, weighing approx. 500 gigatons, have melted this summer, which is 25-50% more than in a typical year.
According to Jyllands-Posten, climate researcher Jason E. Box from Byrd Polar Research Center at Ohio State University, USA, is also saying that the inland ice melting has been particular strong this year:"It is my assessment that we have had the strongest melting since they started measuring the temperature in Greenland in 1873."
Let the good times roll. The Yooper -
Waste heat vs greenhouse warming
RSVP - If you disagree with the level of CO2 forcings, I would suggest taking it to the How do we know more CO2 is causing warming thread; that's where it's appropriate. The value of 2.9 W/m^2 is quite well established from physical theory, from multiple orbital and ground measurements, etc. -
GFW at 06:48 AM on 26 October 2010Measuring CO2 levels from the volcano at Mauna Loa
For those wondering about how the offshore breeze results in higher air descending to the mountaintop, it's just fluid continuity. If air at or below the mountaintop is flowing outward, something has to replace it ... which means air from higher up. While air is not a "perfect fluid", divergence still has to be pretty darn close to zero :-) -
Waste heat vs greenhouse warming
RSVP > if the atmosphere were to always radiate more and more in a way that exactly compensated any positive changes in heat, global warming wouldnt be possible Seriously, I am perfectly aware that "Radiated energy increases as the 4th power of temperature" These two sentences are in direct contradiction to one another, and reflects your inability to accurately visualize the simple logic of how this would play out. If there is a positive change in the rate of heat input, then temperature will increase. If temperature increases, then radiated energy increases. As long as the output radiation is less than the input energy, then temperature will continue to increase, and just as you claim to be aware of, so will radiated energy. If temperature continues to increase, then output radiation will continue to increase, and if it does, it is mathematically and logically inevitable that eventually output will increase to a point where it matches input, at which point temperature increases will stop. If temperature increases stop, then so will changes in output, and since this is precisely the point where input matches output, there will be no more changes to the total energy content of the system. The overall temperature has gone up, but past this point there is no more accumulation. -
nealjking at 06:41 AM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
#54, Berényi; #55, Riccardo: Looking briefly at Ozawa, I notice again and again the phrases: "the hypothesis of MEP," "that might be applicable." Why would I want to construct an understanding of the 2nd law on the basis of something that looks rather speculative? -
The 2nd law of thermodynamics and the greenhouse effect
Berényi - Thunderstorms and hurricanes are excellent examples of increasing local entropy, not decreasing it as you claim, they reduce order. A small turbulent variation in updrafts can trigger a thunderstorm, tipping a temporarily ordered system downslope. Pre-storm states are more ordered, with warm wet air present - a thunderstorm lifts and condenses approximately 5×10^8 kg of water vapor. Hurricanes do much more. The result is higher entropy, more disorder, less concentration of energy. What you have argued is that large scale fractal patterns of water vapor, or cloud formations of some kind, would form as part of local variation within the degrees of freedom of the climate system. Large scale patterns of water vapor (big enough to change the climate, certainly) would require long term persistent order to exist. That's a widespread, persistent low entropy system, and you have presented no evidence for such to exist. Your example of thunderstorms and hurricanes does not support your theory; quite the contrary. More to the point: Ozawa et al 2003, as Riccardo points out, indicates that "turbulent fluid systems adjust themselves to the states of maximum entropy production". Assuming that this is so (and it seems a reasonable hypothesis), the climate system is already adjusted to the state of maximum entropy production. Your hypothesis that the climate will adjust to increase entropy and avoid warming fails to consider this - that it's already adjusted in that fashion, and that this max entropy production is part of the existing climate and climate feedbacks. Maximum entropy production won't suddenly switch on in response to climate forcings - it's already there, already part of the system, already part of the climate sensitivity. It certainly won't kick in abruptly to save us from greenhouse gas heating. -
RSVP at 06:29 AM on 26 October 2010Waste heat vs greenhouse warming
KR #333 "Anthropogenic heat flux = 15 TW/year" You mean 15 TW all year. Day and night. As there are 60 x 60 x 24 x 365.25 = 31536000 seconds in a year, that gives you 31536000 x 15 x 10E12 = 473040000 x 10E12 or 473 x 10E18 Joules. The heat flux value you cite for CO2 is an estimate, not a measurement; derived by correlating the observed warming with the observed CO2 increase and contrasting this with the known total solar heat flux. But the situation would be completely inverted, IF you started with the opposite assumption. So the only way you could be right about this is if you can prove that all that energy being injected into the environment is having no impact, (instead of warming things, it hightails for the stars). This is hard to believe as glaciers and polar caps melt before us. -
Riccardo at 06:17 AM on 26 October 2010The 2nd law of thermodynamics and the greenhouse effect
nealjking "I am not an expert on non-equilibrium thermodynamics." you're in good company, I don't think you'll find many experts on non-equilibrium thermodynamics around, let alone on the MEP principle. As with the 2nd law of thermodynamics (just a reminder, it's the topic of this post) you'll find, instead, a lot of misuses. Apart from Miskolczki "theory", there's really no contraddiction between an increased GHG effect and the MEP principle. A carefull look at section 3 in Ozawa et al. 2003, and fig. 5 in particular, should make it clear.
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