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archiesteel at 11:16 AM on 27 October 2010Isn't global warming just 2 °C and isn't that really small?
@adrian: "According to UHA satellite data the last week hasn't been this cold in many years" Are you *really* going to gauge future climate from *one week* of data? "After 14 years of nearly flat temperatures that's 1996 to now." Hardly. Using the same UAH (not UHA) data:"Three or four years of actual cooling should put a stake in the heart of the AGW agenda." Considering we've had about 40 years of warming, we should have expected the spectre of climate change denialism to never again rear its ugly head, but I guess there's no rest for the wicked...
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The 2nd law of thermodynamics and the greenhouse effect
BP, ok sorry I misunderstood the water vapor point somewhat. RE the convention of moving along the landscape vs. changes to the landscape: it seems to me that distinguishing these concepts is somewhat important to your hypothesis is it not? MEP states that the system will tend towards the maximum path of entropy production given the constraints. As I understand it, it says nothing about whether a change in constraints can raise or lower the entropy production of the system. If positive feedbacks are thought of as changes in the constraints of the system (as the net consequence of the initial forcing), then there is no reason to predict that entropy production must increase (or stay the same) as a result of these changes. In this way, positive feedbacks can reduce entropy production with no contradiction to MEP. In short, how do you determine whether positive feedbacks are changes to the path of entropy production or changes to the constraints of the system? -
adrian smits at 11:03 AM on 27 October 2010Isn't global warming just 2 °C and isn't that really small?
According to UHA satellite data the last week hasn't been this cold in many years for this old rock and I expect before this la Nina ends its gonna get a lot colder yet! Lets just wait 4 maybe 5 more years and see where we are at before doing anything rash.After 14 years of nearly flat temperatures that's 1996 to now. Three or four years of actual cooling should put a stake in the heart of the AGW agenda.Response: Your assertion of "14 years of nearly flat temperatures" is discussed in "Phil Jones says no global warming since 1995" as well as "It's cooling" or even "It hasn't warmed since 1998". Please take that discussion to a relevant thread. -
Albatross at 10:29 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
KR @93, I have been following this debate with interest from the side lines. I think your last sentence sums everything up nicely-- a very elaborate red herring at that. So this "debate" all seems an effort by BP to distract form the subject at hand. Or does BP agree with G&T's misunderstanding that the so-called "greenhouse effect" somehow contradicts the second law of thermodynamics? There is really nothing to debate concerning the validity of G&T's work, b/c the science on that is settled-- G&T have been shown to be wrong. If BP is trying to argue that the climate system has some alleged significant negative feed backs, surely that debate belongs on a more appropriate thread, and not here. -
scaddenp at 10:26 AM on 27 October 2010Blaming global warming on the oceans - a basic rebuttal
Joe, I have no doubt about the importance of ocean in climate mechanisms (why else include oceans in climate model) but I do not think you can attribute climate change on current scale to UNFORCED change in ocean circulation. As to higher glacial max T with lower CO2, I would point out that glacial cycle is very slow with time for equilibrium. Climate is currently out of equilibrium with forcing. (note TOA energy imbalance). Given ocean mixing rates, I find it hard to see how ocean can equilibrate to current CO2 forcing in much less than 1000 years. -
The 2nd law of thermodynamics and the greenhouse effect
Berényi - Once again you are proposing a complex hypothesis of negative feedback that will defeat global warming: "This rearrangement would counteract GHG effect on entropy production rate (like a negative feedback)". And once again this is contradicted by the actual data. Such a MEP effect would already be in effect now, and in the past, and would be part of measured climate sensitivities. There is no such negative feedback observed in the data. And if your hypothesis is contradicted by the data, it's time for a new hypothesis. This entire MEP side excursion is a red herring. -
Joe Blog at 09:46 AM on 27 October 2010Blaming global warming on the oceans - a basic rebuttal
scaddenp at 07:54 "since oceans cant generate heat, then heat from oceans cant be forcing only a mechanism." This is simply not true,the rate of evaporation/water vapor, is dependent on the ocean surface T, the ocean surface T is a product of solar heating/back radiation/ back radiation is a product o atmospheric T, which is a product of ocean T/energy export in to the atmosphere, and the thermal characteristics of the atmosphere... the real variable being water vapor/or surface of the oceans T. So if you change the energy distribution around the globe, by moving energy from below the surface in the tropics to the surface at higher latitudes, you can force a change... By raising the average surface T, you raise the average evaporation/and the average GHE, and the back radiation will increase in line with atmospheric T's... you are going to have a hard time explaining past interglacial max T's without taking this into account... CO2 levels were lower, but T's were higher... You are assuming that its a linear relationship between surface T's and oceanic T profiles. -
MarkR at 09:46 AM on 27 October 2010Isn't global warming just 2 °C and isn't that really small?
Joe Blog, I will clarify this later. What I meant was that 2 C global warming from today's level would put us beyond what appear to have been the warmest temperatures of the past 600,000 years. Which is one reason why we're not sure about feedbacks beyond that point! -
Berényi Péter at 09:45 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
#90 e at 08:30 AM on 27 October, 2010 You're basically saying that an increase in water vapor is a decrease in entropy, so this feedback is impossible given MEP. No, I would never claim such a thing. Water vapor is free to do whatever it is inclined to. I just say given MEP some rearrangement of the climate state is likely in response to increased IR opacity in order to approach maximum entropy production rate under the new circumstances. This rearrangement would counteract GHG effect on entropy production rate (like a negative feedback). Water vapor redistribution is just a possibility. Average opacity of the atmosphere can decrease happily in weak H2O IR absorption bands even with increasing average moisture, provided its distribution gets a bit more uneven (higher moments are increased). It can happen on all scales, including sub-grid ones relative to computational climate models. how do you distinguish between a movement along the potential entropy production landscape, and a wholesale change to that landscape? It is a matter of convention to some extent. What you usually consider a forcing is supposed to rearrange the landscape while so called feedbacks only push the climate state around in the phase space. Is it simply a matter of external forcings vs. internal? If so, is not the ocean "external" with respect to the atmosphere? I don't think there are internal forcings, I would rather call changes not forced by external agents unforced ones. As the climate system is close to a critical state (see SOC - Self-Organized Criticality) one would expect the correlation length go up implying large spontaneous (unforced) fluctuations on all scales. And no, the ocean is in no way external to the climate system. In fact most of the climate happens in the oceans, there's thousands of times more mass in them than in the atmosphere. -
Albatross at 09:06 AM on 27 October 2010Isn't global warming just 2 °C and isn't that really small?
Hi MarkR, In the above figure looks similar to what Lindzen showed in his debate against Dessler to try and convince people that there is no reason for alarm ;) Joe Blog, "show most o the past interglacials warmer than this one" Well, maybe not by 2100....we are probably going to be experiencing a super interglacial. According to Petit et al. (1999) previous inter-glacials were about +2 to +3 warmer than at the time of the most recent stratum in the core (circa 1950 if I remember correctly). We are probably in for at least another +2 C warming. Now, what were sea levels during those previous inter-glacials? -
Berényi Péter at 08:48 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
#88 Riccardo at 08:14 AM on 27 October, 2010 What do you mean by "everything else held constant"? I mean what is ordinarily called a no feedback situation. That is, cloudiness, snow cover, atmospheric water vapor distribution, winds, ocean currents, vegetation, etc. are not allowed to change in response to increased IR optical depth. I say in this specific case entropy production rate gets smaller than it was before optical depth was increased. And the entropy production rate of what, in first place? The global entropy production rate in W/K, measured as difference between entropy of outgoing longvawe vs. incoming shortwave radiation. Can't you increase entropy production rate by increasing surface temperature? No, I can't. Not as if I have not tried, but all simplified radiative or radiative-convective models I have checked so far have this vexing property. As surface temperatures are increased, entropy production rate declines. I conjecture a general principle is at work in the background. The MEP usually also implies minimum entropy contents of the system and higher temperatures mean higher entropy. But I do not have a formal proof (yet). Anyway, if you could show us an understandable climate model that goes against this conjecture, that would be informative. I've never heard anyone claiming the impossibility of positive feedback based on MEP principle You are welcome :) -
The 2nd law of thermodynamics and the greenhouse effect
BP, Ok, I think I see what you're doing. You're basically saying that an increase in water vapor is a decrease in entropy, so this feedback is impossible given MEP. Of course, if this claim was true, atmospheric water vapor could never increase. Of course, we know from empirical evidence, that water vapor does increase. In a more general sense, how do you distinguish between a movement along the potential entropy production landscape, and a wholesale change to that landscape? Is it simply a matter of external forcings vs. internal? If so, is not the ocean "external" with respect to the atmosphere? -
Daniel Bailey at 08:23 AM on 27 October 2010Medieval Warm Period was warmer
Re: Heidi (12)"However, I can tell you, most people have neither the education nor the time to understand climate science at this level and are, therefore, easy prey for the skeptics."
I am in 100% agreement with you on this one. The vast sea of humanity, frankly, doesn't give a darn about climate change nor is equipped with the background to understand it even if served up in bite-sized sound bites on the evening telly by the talking head du jour. The majority of people in this world are quite rightfully concerned with such mundane things as a roof over their heads, jobs that put food on the table, the health of their children or aging parents or just being frightfully occupied with the fight for survival itself. And I do not blame them for those preoccupations."Ultimately, of course, you will need to bring us along with you to achieve significant policy change... Is that the goal of this website?"
John specifically spells out the goals of this website here. Not to put words in his mouth (but since the vast majority of infrequent visitors never click on links provided), but this site exists as a repository for the truth about things climate. There exist so many active disinformation sites that exist solely to deceive the unwary and uneducated that there must exist some bastion of truth to fight against the darkness being imposed on science. Those seeking the truth on various matters related to climate can come here, examine the evidence (pro and con), and make up their own mind. What they do with the information they take away is up to them. Significant policy change would be nice, but is only achievable if enough sleepers awake to fight back and make a difference before it is too late to do so. But, hey, a journey of 1,000 miles starts with but a single step, right? The Yooper -
Berényi Péter at 08:18 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
#87 e at 07:43 AM on 27 October, 2010 the plain reading of this comment is that you were saying exactly what I accused you The key phrase is you need the same climate state to be found right at a peak on the rearranged landscape (otherwise there is a direction in the phase space along which a small displacement of the climate state would increase entropy production). I have no idea how "a total rate of entropy production exactly equal to the previous local maximum" would follow from it. But maybe I was not clear enough. -
Riccardo at 08:14 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
Berényi Péter #85 there's something I don't get in your point #1. What do you mean by "everything else held constant"? Will you let the system evolve? By changing what? And the entropy production rate of what, in first place? Also, in #3 I do not understand why restoring the "right" entropy production rate cannot be a positive feedback in climate terms, i.e. an increase in surface temperature as opposed to in entropy production rate. Can't you increase entropy production rate by increasing surface temperature? Maybe it's just a consequence of the problem in #1. I've never heard anyone claiming the impossibility of positive feedback based on MEP principle. -
Joe Blog at 07:52 AM on 27 October 2010Isn't global warming just 2 °C and isn't that really small?
"Ice and sediment cores suggest we haven’t been this warm in at least 600,000 years so we’re not sure – but this could trigger a lot more warming." Really? all the ice core and sediment reconstructions ive seen show most o the past interglacials warmer than this one.... i think you may mean co2 levels ;-) -
The 2nd law of thermodynamics and the greenhouse effect
BP, I was referring specifically to this comment: >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. If you misspoke, then that's fine. But the plain reading of this comment is that you were saying exactly what I accused you of claiming: that negative feedback is the only probable outcome assuming MEP. Please don't accuse me of constructing strawmen when I'm responding directly to a statement you made. -
CBDunkerson at 07:24 AM on 27 October 2010Waste heat vs greenhouse warming
RSVP #345: First, nothing in your reply explains why the radiation outflow from the Earth would have a fixed limit... without such an explanation your analogy has no relation to reality. If your reference to the surface area of the Earth being finite was meant to be such... I'm hard pressed to believe even you can take that argument seriously. The more energy coming into a system, regardless of its size, the more energy must go out. Otherwise we've got energy magically ceasing to exist. "It would be interesting to know if you think waste heat could ever cause global warming if CO2 concentration were at its pre Industrial Revolution level." Can't have been too interesting... given that I already answered that question earlier in this thread. "At this point in the discussion it doesnt seem like the number matters, since from what I can tell no one has admitted that this energy could possibly accumulate." Correct, waste heat cannot possibly accumulate in the climate system. Again, barring some explanation for why an increase in energy input would NOT result in a corresponding increase in energy output (the 'narrow slot' in your dam analogy) it is impossible for any such input to 'accumulate over time'. The current waste heat level causes a temperature increase, which causes greater radiation outflow, which prevents any further temperature increase. -
Tom Dayton at 07:17 AM on 27 October 2010Models are unreliable
mistermack and BP, there is an example of parameterization at Science of Doom's page CO2 - An Insignificant Trace Gas? Part Four. -
muoncounter at 07:07 AM on 27 October 2010Measuring CO2 levels from the volcano at Mauna Loa
#17: "most industrial countries have higher levels than the middle of the Pacific Ocean. " Excellent: Direct, verifiable, repeatable experimental evidence of the fact that atmospheric CO2 increases because of fossil fuel consumption. -
muoncounter at 07:02 AM on 27 October 2010Models are unreliable
#266: "Sub-grid processes, aerosols and the like are always parametrized in models, ... chosen to reproduce the past" Do you have a better procedure in mind? On the same page, von Neumann also said "I think that it is a relatively good approximation to truth — which is much too complicated to allow anything but approximations — that mathematical ideas originate in empirics." -
Tom Dayton at 07:01 AM on 27 October 2010Models are unreliable
BP, parameterization is not as freewheeling as you imply. See the RealClimate FAQ section "What is tuning?" and even the Wikipedia entry on parameterization (climate). Also see the list of parameters at climateprediction.net. -
The 2nd law of thermodynamics and the greenhouse effect
Berényi - "If you still maintain there must be a positive feedback in the climate system (for example by water vapor, high clouds or whatever), you have several options to attack my reasoning"... To be quite specific, and to repeat what both 'e' and I have written on this thread: if the MEP principle is operative, it is part and parcel of the existing climate sensitivities. Straightforward 'black-box' testing of climate sensitivity from paleo evidence, for a variety of forcings, indicates that there is no major negative feedback such as you postulate. You've been avoiding that point of both our replies for some time now. MEP does not magically prevent global warming. -
Berényi Péter at 06:40 AM on 27 October 2010Models are unreliable
#263 e at 05:23 AM on 27 October, 2010 Since the model is built on physical laws and not on direct statistics, there is no reason to assume that a particular model could ever recreate past climate behavior, unless that model has some basis in reality The situation is not so nice as you paint it. Sub-grid processes, aerosols and the like are always parametrized in models, that is, these are not derived from first principles, but are chosen to reproduce the past. And as von Neumann said "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk." Computational climate models tend to agree on past trends but diverge considerably in their predictions. It is a sure sign they do use the leeway provided by the parametrization process and use it disparately. -
Tom Dayton at 06:37 AM on 27 October 2010Models are unreliable
mistermack, expanding on e's answer, for more explanation of how observations are used to improve climate models, see the RealClimate "FAQ on Climate Models," in particular the questions "What is the difference between a physics-based model and a statistical model," "Are climate models just a fit to the trend in the global temperature data," and "What is tuning?" -
Bibliovermis at 06:11 AM on 27 October 2010Waste heat vs greenhouse warming
RSVP, You are wrong. No amount of repitition of your misconceptions will make them correct. Please read what has already been posted here again, because you have provided nothing new. -
muoncounter at 06:08 AM on 27 October 2010Models are unreliable
#260:"Bridges fall, buildings collapse. Shuttles explode. ... They can get it wrong. " You're forgetting a significant cause of such unpleasant events: Google search 'operator error accidents'. Such is not the case in a climate model, where there is no one to push the wrong button, run past a red signal or close a valve that should be left open. -
Berényi Péter at 05:51 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
#81 e at 02:54 AM on 27 October, 2010 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). No, I have not said such a thing. If you had the impression I had, it's probably my fault. What I am actually trying to say is this:- If IR optical depth of the atmosphere is increased by a small amount by adding to it some well mixed greenhouse gas while everything else is held constant, entropy production rate would decrease. I do not have a rigorous proof of this statement, but based on simplified model calculations I believe it's true.
- If that everything else is allowed to adjust now to the new situation, it would not change in a way that leads to further reduction of entropy production rate (MEP is used at this step).
- Therefore this spontaneous adjustment (a.k.a. feedback) does not amplify the effect of increased IR optical depth, but either leaves it unchanged or attenuates it, that is, the feedback is either neutral or negative.
- You may try to show that in some cases increased IR optical depth alone does not imply a decrease in entropy production rate.
- You could demonstrate the climate system has a unique structure that makes the MEP principle nonoperational in this case.
- Or show us while feedback on entropy production rate is indeed not positive, it can still be positive on surface temperatures.
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Heidi at 05:50 AM on 27 October 2010Medieval Warm Period was warmer
Thanks for the information, scaddenp. I understand your position, Doug. Unfortunately, there seems to be an unmet need for a lighter approach to climate science and global warming. Parts of this website fit the bill, others fall short. Mind you, I love listening in on your arguments and appreciate the intellectual rigor. However, I can tell you, most people have neither the education nor the time to understand climate science at this level and are, therefore, easy prey for the skeptics. Ultimately, of course, you will need to bring us along with you to achieve significant policy change... Is that the goal of this website? -
The 2nd law of thermodynamics and the greenhouse effect
e - Your objections to the introduction of the MEP hypothesis are extremely well written. I believe that's essentially what I attempted to say here, albeit not as clearly as you did. The MEP hypothesis, even if true, won't suddenly kick in to save us from global warming. If it's present, it's always been present, and can be considered part of the current feedbacks. Berényi still appears to be searching for the "mystery mechanism" that will induce negative feedback and cancel out AGW. -
Models are unreliable
mistermack, to add to fact that models have been successful in forecasting: Predicting the past is still a prediction (see retrodiction). If you build a simulation of a physical system, it is appropriate to test that simulation by comparing it to past performance of the real system. This is true of any physical model, including models of bridges and space shuttles. The fact that you are comparing to past data does not mean that the simulation has past data "programmed in" as you are implying. What you are thinking of is a statistical model, where the inputs are directly mapped to outputs via a mathematical relationship derived directly from historical data. This is not how physical climate models are derived. Since the model is built on physical laws and not on direct statistics, there is no reason to assume that a particular model could ever recreate past climate behavior, unless that model has some basis in reality. If the basic physics underlying the model are significantly off, then no amount of tweaking would ever result in an accurate recreation of past performance. The fact that it can recreate past performance is therefore evidence that the model is correct, since the likelihood is very slim that the model would be able to accurately recreate real performance if it was significantly wrong in its recreation of physics. -
archiesteel at 04:54 AM on 27 October 2010Models are unreliable
@mistermack: you have yet to demonstrate exactly how models are unreliable. You should provide evidence that supports your allegations, otherwise it's hard to take them seriously. -
Riccardo at 04:51 AM on 27 October 2010Models are unreliable
mistermack so we have a phenomenon, we build a theory (a model) and compare it to the observed phenomenon. If they agree I throw the model away because it is trivial, if it does not I throw it anyway. I'm puzzled. More seriously, the first model dates back to 1896. Not enough subsequent data to test it? Yes, of course. It has then be refined and tested again, and so on for many decades. Apparently you're seing just last generation of models, as if they came out of nowhere. -
mistermack at 04:44 AM on 27 October 2010Models are unreliable
To answer the point about physics and chemistry, it's stretching it rather a lot to say that since the models involve (or are based on) physics and chemistry, they must be right. Bridges fall, buildings collapse. Shuttles explode. Their design is always based on maths, physics and chemistry. They can get it wrong. But we have long experience of successful building. We have zilch of successful climate forcasting. So I think I'm right to be sceptical of the models' ability to get it right at this stage.Moderator Response: You are incorrect that we have "ziltch" experience in successful climate forecasting. You really should actually read the posts. Be sure to click the "Intermediate" tab. -
mistermack at 04:33 AM on 27 October 2010Models are unreliable
Mueoncounter, my point isn't that we shouldn't have models, or that you shouldn't seek to improve them by using previous data. I take all that as obvious. My problem is that when I look on this site, or anywhere, for good evidence that manmade CO2 is going to cause significant harm, the only evidence of any significance is that the models match the data, or the data matches the models. Since the models are developed to match the data, what do they expect? Don't quote it as evidence, that's all I'm saying.Moderator Response: The models are not developed merely match "the data" in the pejorative sense you are using the term "the data." Please actually read the material that I and others have pointed you to, for explanations of exactly how observations are used in model construction. Your mere repetition of your contentions is not contributing to the discussion. -
PeterRossy at 04:33 AM on 27 October 2010Antarctica is gaining ice
He wasn't able to tell certanly that global warming was the reason but the ice weight loss from Antarctica is being influenced by warm water temperatures, which in turn are caused by climate change and altered ocean currents. The losing of ice is thought to be partly attributable to the processes that take place over thousands of years. “How it reponds to climate takes place over many different time scales,” Professor Bamber said. “There are changes taking place now that are a result of what happened to the climate 12,000 years ago.” Athmosphere thermal rises are caused by climate change are more visible at the poles than in other regions of the world but researchers have an incomplete understanding of the mechanisms controlling ice in Antarctica. -
The Inconvenient Skeptic at 04:30 AM on 27 October 2010Measuring CO2 levels from the volcano at Mauna Loa
The only problem with the Mauna Loa station is the spelling. Otherwise it provides solid results on the global CO2 levels. It should also be noted in later versions that the US typically has higher levels of CO2 than the station in Hawaii. In fact, most industrial countries have higher levels than the middle of the Pacific Ocean. -
RSVP at 04:27 AM on 27 October 2010Waste heat vs greenhouse warming
KR #344 I agree analogies are not one to one. -
muoncounter at 04:21 AM on 27 October 2010Models are unreliable
#253: "told you to pick the next Kentucky Derby winner" That would be akin to predicting the next hurricane's landfall location from a study of prior landfalls. A more reasonably-posed analogy might be to conclude from a study of prior races that there are factors that categorizes the field of entrants into 'likely' winners and 'likely' losers (forgive my alarmist language). For example (from wikipedia): "No horse since Apollo in 1882 has won the Derby without racing at age two." That would make a 'very unlikely' outcome. So from a study of climate, it is perhaps unreasonable to predict a specific heat wave, but not at all unreasonable to build a model that says: "would these [extreme weather] events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?", an appropriate answer in that case is "almost certainly not." But what is all this about models not having a peek at prior data? On another thread, there have been comments to the effect that models and evidence somehow pollute each other; that makes no sense to me. What use is a model if it is not built on prior data and tested by subsequent data? -
RSVP at 04:20 AM on 27 October 2010Waste heat vs greenhouse warming
CBDunkerson #342 "Please explain what mechanism you think exists which similarly constrains the outflow of energy from the Earth to a fixed amount." In the third paragraph of #341 I already say that outflow does not only depend on temperature, but also the size of the Earth or more precisely its surface area (which is actually finite believe it or not), plus not everything has the same emissivity, especially the different gases we are breathing all day. It would be interesting to know if you think waste heat could ever cause global warming if CO2 concentration were at its pre Industrial Revolution level. In other words, if there was no anthropogenic CO2 accumulated. Try to imagine that man was still somehow dumping the same 0.474 x 10E21 J of waste heat into the environment each year without the CO2. (Say all nuclear or something.) As calculated above, this is enough energy to raise the temperature of the atmosphere 0.1 degrees in one year (assuming no losses). However, it is fair to assume that some of this energy would immediately begin to thermally radiate and be lost forever, such that after one year the atmosphere's temperature only gets raised 0.01 degrees, or 0.001 degrees. At this point in the discussion it doesnt seem like the number matters, since from what I can tell no one has admitted that this energy could possibly accumulate. You have to remember there is no waste heat night. It never stops, and has generally been on the increase. (see graph at the top of this page) http://en.wikipedia.org/wiki/World_energy_resources_and_consumption -
Daniel Bailey at 03:47 AM on 27 October 2010CO2 lags temperature
Re: Tom Dayton (149, 203) and mistermack (150, 204) Interesting & germane new article out in nature geoscience today, "Southern Ocean source of 14C-depleted carbon in the North Pacific Ocean during the last deglaciation". Germane, as it adds weight and evidence to the "burp" mechanism under discussion. Interesting also was the development of neodymium isotope values as a proxy. Science Daily write-up here. The Yooper -
DSL at 03:23 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
And to follow up on BP, here's at least one place where the burning of G&T takes place. -
JMurphy at 03:20 AM on 27 October 2010Models are unreliable
Oops, sorry - half my links were already in the green box. Sorry ! -
JMurphy at 03:18 AM on 27 October 2010Models are unreliable
mistermack, as well as looking at the Moderator's comment, you can investigate models further in WIKIPEDIA (Climate Models, Global Climate Models), NASA (The Physics of Climate Modeling), and THE DISCOVERY OF GLOBAL WARMING (Simple Models of Climate). How could the first models have peeked at the previous data ? You're right about one thing, though, they aren't just constructed using the laws of physics : there's a lot of maths in there too, as well as some chemistry. -
JMurphy at 03:01 AM on 27 October 2010The 2nd law of thermodynamics and the greenhouse effect
mistermack wrote : "If I saw this suggestion, about the second law, my initial reaction is that it's laughable, and not worth answering." Most so-called skeptical 'arguments' are laughable (as are most of those bringing them forth, e.g. Monckton), but if they are not responded to - and dismissed as the laughable nonsense they are - the so-called skeptics claim that as being a victory and 'proof' that AGW is false. Many of those 'arguments' are now regarded as zombies because, no matter how many times they are refuted, they keep coming back from the dead. But continually refuted they must be. The same goes for the laughable 'arguments' from creationists - if they weren't shown as false, more and more people would believe there was something to them, and there are more than enough people who believe that creationist nonsense as it is ! -
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.
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