Recent Comments

Prev  1565  1566  1567  1568  1569  1570  1571  1572  1573  1574  1575  1576  1577  1578  1579  1580  Next

Comments 78601 to 78650:

78601. Karamanski at 15:00 PM on 24 July 2011
       Gripping video of Arctic sea ice melting away before your eyes
       From which region of the Artic Ocean was this footage taken?
       Response:

       [DB] The buoy is approximately in the location of the crosshair placed on the map below:

       

78602. Riduna at 14:09 PM on 24 July 2011
       China, From the Inside Out
       An interesting article, though I would challenge its conclusion that “the West” will be playing catch-up to China before the end of the century – unless of course “the West” is an euphuism for the USA. It is true that in an effort to reduce visible pollution, the dirtiest emitters are either being closed or are being ordered to fit scrubbers to reduce their emissions. This of course refers to emission of particulates, not greenhouse gases which are steadily rising and are destined to do so for at least 50 years. Reducing aerosol emissions is commendable for popular health but it will result in an increase in the level of solar radiation reaching the earths surface which, in combination with growing CO2-e emissions, will result in escalating global warming. The primary problem facing China, India, in fact all major CO2-e emitters is clear and simple. It is to provide growing national energy needs while reducing the need to burn fossil fuels and by 2050, burning none. China has made a good but far from adequate start in this regard. Both fixed and mobile plant and equipment, including all forms of transport, need to transfer from oil-based fuels to electricity, a fact China is aware of as evidenced by its R&D into efficient electric vehicles, notably cars and trains. All very well you may say – but where is the increased level of electricity coming from, if not fossil fuels? Most of it will come from sunlight. The technology to achieve cost-efficient conversion of sunlight to electricity is not quite here yet but it is being developed in a number of countries albeit in a fragmented and inefficient way. When available, it will be willingly embraced by countries such as China which loath being increasingly dependent on the vagaries of supply and growing cost of imported fossil fuels. It is dangerously misleading to talk of how well China is doing with its low per capita CO2-e emissions. They are irrelevant as evidenced by the fact that Australian annual emissions, the highest per capita in the world, equate in total to a few days emissions by China. With regard to effect on global warming and climate change, the only relevant figure is the total emissions per country, not per capita. We delude ourselves if we “China has one of the lowest levels of CO2-e emissions per capita, so all is well with the world and China”. All is not well when China’s total emissions were over 7.7 billion tones in 2009. All is not well when China intends to increase those emissions every year for the next 40 years. Per capita, China does very well but in total it very clearly does not and it must do better – a lot better with power generation and industry which is largely unregulated and 40 years out of date when it comes to emissions.
78603. Eric the Red at 12:49 PM on 24 July 2011
       Milankovitch Cycles
       Rob, The timing correlates fine. It is the rapid warming that has me puzzled. One would think that since the changes in eccentricity occur slowly, that the temperature would follow at a similar pace. Yet, that does not appear to be the case. At least, according to the ice core data.
78604. Rob Honeycutt at 12:08 PM on 24 July 2011
       Milankovitch Cycles
       Camburn... Are you really trying to suggest that there is no relationship between the pace of glacial-interglaicals and Milankovitch cycles? Eric... Same question.
78605. DSL at 11:46 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Must be a slow news day if everyone's willing to re-heat (ha ha) this thread. May I suggest a new article: "Heating up the Lexicon of Physics" or "HaIRNET: Heat and Infrared Radiation / Net Energy Transfer -- Could Be Important" or the new skeptical argument "GHE doesn't exist because you don't accept my definition of 'heat'."
78606. Camburn at 11:15 AM on 24 July 2011
       Milankovitch Cycles
       That is also one of the problems with the Milankovitch theory. That was my point, the correlation does not mean causeation. However, there may be a sudden force that we have as of yet not recognized. The force seems to initially drive global climate equally between hemispheres.
78607. Doug Mackie at 10:33 AM on 24 July 2011
       OA not OK part 8: 170 to 1
       JeffT, the algebra gets a wee bit tricky but it is easy to define the fraction of each species only in terms of K1, K2 and [H₃O⁺]. Try googling dissociation of a diprotic acid. If there is huge interest we may consider an extra post to go through the equations.
78608. Tom Curtis at 10:32 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Thankyou mc. The link should be http://web.mit.edu/16.unified/www/SPRING/propulsion/notes/node119.html
78609. Christina McGraw at 10:29 AM on 24 July 2011
       OA not OK part 9: Henry the 8th I was (*)
       Ken Lambert @5. Skeptical Science - and other blogs - have plenty of good short posts on the impacts of OA. However, as we stated in the introduction to the series (and have mentioned several times since), the purpose of these posts is to give readers interested in the chemical and physical processes of OA the background information they need to understand the commentary on the web. We are certainly not introducing graduate-level concepts, but high school and 1st year university chemistry is helpful. Perhaps it was not clear that we would answer the How can we... question in the next post. The post has been modified to state this clearly.
78610. Eric the Red at 10:29 AM on 24 July 2011
       Milankovitch Cycles
       Whatever the effect of Milankovitch-driven cylces, on thing is clear from the temperature record - Earth slowly slips into an ice age over tens of thousands of years, followed by a sudden rise into a warm interglacial. Can Milankovitch theory explain this? This appears to be opposite to the bifurcation diagram.
78611. Doug Mackie at 10:26 AM on 24 July 2011
       OA not OK part 9: Henry the 8th I was (*)
       Oh dear Ken. Haven't you been paying attention? The series will run to about 20 parts by the time we are done. Sit back and enjoy.
78612. muoncounter at 10:02 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       damorbel#1098: "If this 'ignorance of source temperature' on the part of photons is the basis of your science then I suggest you think again. " Please, not that again. You've already contradicted yourself on the topic of 'photon temperature' on this thread.
       Response:

       [DB] Perhaps a new rule: Damorbel's Law (ala Godwin's Law).

       When someone repeats/resurrects a point already refuted on the same thread by that selfsame poster, Damorbel's Law is invoked declaring the argument forfeit and all subsequent comments by that poster on that thread may be safely ignored.

       One may safely then consider it already invoked on this thread.

78613. LazyTeenager at 09:58 AM on 24 July 2011
       OA not OK part 9: Henry the 8th I was (*)
       Keith Hunter at 13:35 PM on 23 July, 2011 LT @1: they amount to the same thing. Henry's Law describes the equilibrium solubility of a gas for a given atmospheric concentration. --------- Are you sure? Henry's law only applies at low partial pressures. So at high partial pressure of CO2 what happens? Does the amount of CO2 dissolved in water reach a maximim limit in the same way that a dissolved solid reaches a limit?
       Moderator Response: Given the current atmospheric concentration of CO₂, your line of questioning is not relevant to ocean acidification. Please stay on topic. Thank you for your help in this. Doug
78614. Tom Curtis at 09:42 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       With indulgence:

       "If in the interior of the same solid we imagine a plane M parallel to those which bound it, we see a certain quantity of heat flows across this plane during unit of time..."

       (My emphasis) Joseph Fourier, "The Analytical theory of Heat", 1878; p 105.

       "The concept of heat 'flowing' went out with the 'fluid' concept of heat i.e. caloric."

       Damorbel's theory of pedantary, 2011.

       "Did Fourier get it wrong?"

       "Title: Heat flow in the solidification of castings Author: Adams, Clyde M Advisor: Howard F. Taylor. Department: Massachusetts Institute of Technology. Dept. of Metallurgy Publisher: Massachusetts Institute of Technology Issue Date: 1953"

       "Title: Heat flow over the equatorial mid-Atlantic ridge. Author: Folinsbee, Robert Allin Advisor: Gene Simmons. Department: Massachusetts Institute of Technology. Dept. of Geology and Geophysics Publisher: Massachusetts Institute of Technology Issue Date: 1969"

       "Title: Heat flow in solidification of alloys. Author: Campagna, Alan John Advisor: Merton C. Flemings. Department: Massachusetts Institute of Technology. Dept. of Metallurgy and Materials Science Publisher: Massachusetts Institute of Technology Issue Date: 1970"

       Heat flow and material degradation during laser metal forming 1985 16.5 Steady Quasi-One-Dimensional Heat Flow in Non-Planar Geometry So not only is "heat flow" a concept used in various MIT dissertations throughout the 20th century, it is a concept used in MIT lectures on Thermodynamics in 2007.
       Moderator Response: [mc] Closed italics tag. Link to '16.5 Steady Quasi' missing.
78615. scaddenp at 09:22 AM on 24 July 2011
       Milankovitch Cycles
       Well lets see. Milankovitch-driven change in TSI causes much bigger changes in albedo for NH compared to SH, that is clear. It also can cause a much bigger change in CO2 and CH4 because of vegetation change, methane hydrate location, and swamp sources of both gases. The change in GHG concentration particular creates a global forcing, not just a hemispheric one. The hypothesis is testable by doing the maths and seeing how the forcings work out. See Ch6 of AR4 for the numbers on change from LGM. The inter-hemispheric connection is only a "problem" if you wish to ignore GHG forcings. On the 100k problem with milankovitch, I do agree that we have too many theories and not enough data to test them. Not much of relevance to current climate change however.
78616. Camburn at 07:36 AM on 24 July 2011
       Milankovitch Cycles
       Rob: As good a guess as any. I have read so many theories on this, with none of them proveable. I know this article works on TSI basically because of the orbital changes. One thing this article does not mention, which I think at least bears thinking, is what effect does the magnetic field have? As we orbit with the Mil cycle, we are also doing a baycenter orbit. Then there is the stage 5 question when the cycle does not match the timing. I think the theory is interesting, but the lack of matching further back historically causes one to ponder the actual cause/effect question. The good thing is it causes one to think.
78617. Rob Honeycutt at 07:04 AM on 24 July 2011
       Milankovitch Cycles
       Camburn @ 14... How about ice albedo feedbacks? Melting ice in the Arctic is going to cause a more rapid albedo feedback that would Antarctic land ice. The total ice mass in Antarctica is many times what it is in the Arctic. Same reason we get Arctic amplification as a result of warming. Presumably the reverse would be true of cooling. This is just a quick guess on my part. Admittedly I'd have to do some research to justify the claim.
78618. Philippe Chantreau at 07:01 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Damorbel is at it again, after demonstrating how willing he was to contradict himself for the sake of argument. "How do you suppose a remote sensing infrared thermometer works if it doesn't relate the photon energy to the temperature of the emitter?" The hot plate of my stove emits IR photons. So does the Sun. No "IR thermometer" can tell whether an IR photon comes from one or the other. We've been there already. Damorbel's total confusion with Wien's law was clearly exposed on that occasion. Now the confusion is back, this time with gravity. It never ends.
       Moderator Response: (DB) Everything has an ending, including one's patience in allowing PRATT to continue to be bandied about.
78619. Bob Lacatena at 06:53 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       1098, damorbel,

       All these arguments about 'back radiation' and the like appear to be based on this idea of heat as a fluid substance and the preictions do not fit the observations.

       This statement is not only wrong, but demonstrates a woefully poor understanding of the subject matter. You appear to be completely oblivious to radiative and molecular physics, and trapped in a 1960s mode. Please educate yourself.

       If this 'ignorance of source temperature' on the part of photons is the basis of your science then I suggest you think again. How do you suppose a remote sensing infrared thermometer works if it doesn't relate the photon energy to the temperature of the emitter?

       You clearly failed to comprehend anything I wrote. Please go back and reread it. At the same time, this statement also represents a complete lack of understanding of radiative physics. Again, go study.

       it applies not only at the microscopic (molecular) level but to the sub-molecular i.e. quantum level.

       No. Go study.

       But how can you have 1 (red) unit going from the atmosphere at 2deg. to the Earth at 5deg. How so? Did Fourier get it wrong?

       No, Fourier didn't, but you do. Go study.

       Any object, including volumes of air, moving in a gravitational field, changes its potential and kinetic energy according to...

       But we're not talking about moving parcels of air. We're talking about stationary air.

       ...but these movements must conform tho the conservation of momentum, potential and kinetic energy, don't you think?

       Okay, this makes it pretty clear that you're one of those people who thinks they know what they are talking about to the point that they are hopelessly lost. Hence, this is all a complete waste of time. Enjoy applying your personal version of physics to the world.
78620. Camburn at 06:45 AM on 24 July 2011
       Milankovitch Cycles
       From some final words of the article: "It seems that the Earth listens to the Northern Hemisphere when deciding to have an ice age. If the North and South are alternatively near and far from the Sun during summer, why has glaciation been globally synchronous?" This question was asked in the article, so I won't dig for references as the article states this as well. That is why I posed the question as there is really no known physical mechanism that would explain this phenomina which indiates we are missing something in the cause/effect relationship.
78621. damorbel at 06:26 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re #1095 Sphaerica you write:- "In thermodynamics there is no such thing as "net heat flow". Yes, there is. Go study." The concept of heat 'flowing' went out with the 'fluid' concept of heat i.e. caloric. There have been many attempts to describe heat and the idea that heat is conserved was gradually replaced with the conservation of energy during the 2nd half of the 19th century. All these arguments about 'back radiation' and the like appear to be based on this idea of heat as a fluid substance and the preictions do not fit the observations. You write:- "If a molecule emits energy in the form of a photon, the receiving molecule does not and cannot know if the emitting molecule was warmer or cooler. The energy of a photon has the relationship E = hv, this is at the basis of quantum theory laid down by Max Planck and further developed by A Einstein, Werner Heisenberg etc., etc. in the early 20thC. This discussion has raised this point about 'photons not knowing the source temperature - I'm sure I have seen it before and it just isn't true! In this respect photons are no different to any other particles. If this 'ignorance of source temperature' on the part of photons is the basis of your science then I suggest you think again. How do you suppose a remote sensing infrared thermometer works if it doesn't relate the photon energy to the temperature of the emitter? Again you write:- "thermodynamics does not apply on an individual molecular level. It applies in aggregate (i.e. at the macroscopic level)." Since thermodynamics is base on the conservation of energy, not heat, it applies not only at the microscopic (molecular) level but to the sub-molecular i.e. quantum level. I suggest you are thinking of statistical mechanics which is indeed very useful for understanding ensembles of freely interacting particles. But statistical mechanics relies just as much on the conservation of energy and the conservation of momentum (both angular and linear) as does themodynamics and quantum mechanics. Further you write:- "I simplified the "temperatures" to 5 for the surface and 2 for the atmosphere, but they are clearly there. The surface temperature should be 4 (the amount coming from the sun) but it is 5. The extra "ray" is the red one, coming from the atmosphere." I am not sure of your meaning here. According to Fourier heat transfer is between two bodies according to the temperature difference you have in your diagram 2 units of heat going from the Earth at 5deg. to the atmosphere at 2 deg - quite possible. But how can you have 1 (red) unit going from the atmosphere at 2deg. to the Earth at 5deg. How so? Did Fourier get it wrong? You write:- "Thermodynamics does not allow gravity to violate (or suspend) the 2nd Law of Thermodynamics, any more than anything else might. [Did you even realize that when you argue that gravity maintains the temperature differential, it is in fact you who are violating the 2nd Law of Thermodynamics?]" What is missing from your argument is the conservation of energy, both potential and kinetic. Any object, including volumes of air, moving in a gravitational field, changes its potential and kinetic energy according to the strength of the gravitational field and the (vector) distance it moves; this is the argument that got Galileo into trouble. As for a volume of gas, it loses kinetic energy as it rises in a gravitational field, changing into potential energy therefore it cools, it is as simple as that. No need to talk about compression and expansion, gas is free to move as it likes in an atmosphere, but these movements must conform tho the conservation of momentum, potential and kinetic energy, don't you think?
78622. Steve Brown at 05:56 AM on 24 July 2011
       The Last Interglacial Part Two - Why was it so warm?
       Steve #15 - You've raised a very interesting question, which I can't answer. It would make a very good topic for a future post, which I'll look into.
78623. Camburn at 05:52 AM on 24 July 2011
       Milankovitch Cycles
       Dikran: I am working from memory at this point. One thing that always stuck to me was also called the Stage 5 problem. I will dig for the Northern/Southern thing. I thought this was common knowledge to anyone who has reserached the Milankovitch cycle.
       Moderator Response: [Dikran Marsupial] Fine, once you can find the data, we can discuss it, but until then it would be better not to distract from discussion of the existing issues.
78624. Camburn at 05:40 AM on 24 July 2011
       Milankovitch Cycles
       Dikran: I understand there are other forcings at work. But for the Milankovitch theory to hold up, the match between the hemmispheres should not be so.
       Moderator Response: [Dikran Marsupial] As I said, present some data that show on what timescale and to what degree they match. That way some meaningful discussion might result.
78625. Steve Brown at 05:39 AM on 24 July 2011
       The Last Interglacial - An Analogue for the Future?
       Andrew #30 - My statement in the post was intended to be ironic. I don't disagree with your explanation.
78626. Camburn at 05:24 AM on 24 July 2011
       Milankovitch Cycles
       There are still questions about exactly how changes in the earth's orbit affect the climate, and especially in why the climatic changes match in the Northern and Southern Hemispheres. Does anyone have an answer to this question? The match in climate changes on both hemispheres indicates that there are other forces in play as well.
       Moderator Response: [Dikran Marsupial] See CO2 is not the only driver of climate. Solar forcing (inlcuding Milankovic cycles) isn't the only forcing either. In addition, you would be better off stating on which timescales you think climatic changes match in the two hemispheres, preferably by refering to a specific dataset.
78627. muoncounter at 04:41 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       damorbel#1083: "distinguish between this compressive heating of the surface and the GH effect?. For me this is critical to the understanding of atmospheric physics and not often discussed." Perhaps an idea is 'not often discussed' because it is clear to most that it has little merit. You appeared as the champion of this idea as far back as comment #125 on this very thread, where the "death knell of the GHG hypothesis really is the effect of gravity on the atmosphere." Rumors of the 'death knell' of the 'GHG hypothesis' have been greatly exaggerated. This is not your personal soapbox; if you have nothing new to contribute, no one really enjoys reruns.
78628. DaneelOlivaw at 04:10 AM on 24 July 2011
       Why Wasn't The Hottest Decade Hotter?
       I've made a spanish version of the first graph for my blog. http://i.imgur.com/Vs9ls.jpg
78629. David Lewis at 02:17 AM on 24 July 2011
       Why Wasn't The Hottest Decade Hotter?
       NOAA put that -0.1 W/m2 differently, by saying it amounts to 1/3 of the increased power of CO2 added since 2000, which has been offset by this stratospheric aerosol effect Solomon et al are suggesting. Last year NOAA said Solomon was looking at water vapor which she had also observed to be variable. She had calculated an effect that "caused surface temperatures to increase about 25 percent more slowly than they would have otherwise", since 2000. The paper. is the same one mentioned in previous comments. "Why Wasn't the Hottest Decade Hotter" is a good title for everything like this.
78630. JosHagelaars at 02:11 AM on 24 July 2011
       OA not OK part 8: 170 to 1
       @Keith Hunter Thanks for the free CO2Calc application. @Jeff T When you increase CO2 concentration in the atmosphere the equilibriums 7, 8, and 9 start shifting and the result is a lower pH, more HCO3(-) and less CO3(2-). In my opinion figure 3 shows this perfectly. Even though you increase the amount of carbon in the oceans by increasing the CO2, you get less CO3(2-). Less CO3(2-) means that equilibrium CaCO3 = Ca(2+) + CO3(2-) shifts to the right and the calcifying organisms won't like that. Look at the table in The Encyclopedia of Earth where you can see some estimates about these concentrations for different dates. And I think they mean by CT and AT : total dissolved CO2 and total alkalinity.
78631. Bob Lacatena at 01:41 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       1094, damorbel,

       ...so CO2 is always going to absorb heat from the warm atmosphere, both by absorbing radiation and molecular collision...

       This one statement is very, very, wrong, and a major source of confusion. First, the energy is being absorbed from the surface, not the surrounding atmosphere. Thus, the surface is warming the CO2, which is in turn warming the surrounding O2/N2 in the atmosphere (it's not the atmosphere warming the contained CO2). Basically, the CO2 absorbs the radiation from the surface (or from other layers of the atmosphere, but ignore that complexity for now). Before the CO2 is able to radiate that energy away again (usually) it collides with an O2 or N2 molecule and passes the energy on that way -- freeing it to absorb more radiation from other sources. Thus, the surface warms the CO2, and the CO2 warms the O2/N2. This behavior is more pronounced near the surface, where the air is denser and collisions are more frequent. As one rises in the atmosphere, and it becomes less dense, the chance of collision is reduced, and so, too, is the time between collisions as well as the chance of receiving energy through absorbing radiation (for the CO2 molecule). As a result, CO2 higher up is more likely to gain energy through a collision, and emit it through radiation. Thus, we have a gradually changing effect, where in the denser, lower atmosphere, CO2 acts to absorb radiation and transfer it to the (otherwise transparent to IR) O2 and N2 molecules. As one rises, the balance slowly changes, until one reaches the very upper troposphere and stratosphere, where the opposite is likely to occur, and CO2 actually acts to accentuate heat loss.
78632. Bob Lacatena at 01:34 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       damorbel, I'm not going to waste of lot of time here, because clearly many others have been down this road before, but here are a few salient points:

       In thermodynamics there is no such thing as "net heat flow".

       Yes, there is. Go study. To provide a simple example, thermodynamics does not apply on an individual molecular level. It applies in aggregate (i.e. at the macroscopic level). If a molecule emits energy in the form of a photon, the receiving molecule does not and cannot know if the emitting molecule was warmer or cooler. It does not and cannot discriminate based on the source of the photon. If that photon is of the correct frequency, then it is absorbed, no matter where it came from. To give another example, do you think that it is impossible to shine a flashlight into the sun? Of course not. The light from the flashlight (some of it) will reach the sun and be absorbed. Far more light/energy from the sun will of course reach and be absorbed by the flashlight. The net flow is from warmer (sun) to cooler (flashlight). but energy still has flowed from the flashlight to the sun.

       I can see nothing in your diagram that shows a warming effect on the surface, thare are no temperatures to be seen, it is not possible to argue for a warming effect without atleast two temperatures.

       Look again. I simplified the "temperatures" to 5 for the surface and 2 for the atmosphere, but they are clearly there. The surface temperature should be 4 (the amount coming from the sun) but it is 5. The extra "ray" is the red one, coming from the atmosphere. Take the time to actually study and understand the diagram before commenting further (although arguing without listening appears to be your modus operandi).

       As you decend through the atmosphere the pressure rises and the temperature rises.

       Wow, really? Except that the pressure is greater near the surface, but not increasing at any particular altitude. Again, no work is being done. The pressure at any altitude is constant. As such, gravity doesn't increase the temperature or artificially maintain a higher temperature. Yes, it maintains the pressure gradient, and a rising parcel of air will do work and cool. But barring that motion, and that actual expenditure of work, the atmosphere should still cool to restore the temperature differential (warm to cool, remember?). Thermodynamics does not allow gravity to violate (or suspend) the 2nd Law of Thermodynamics, any more than anything else might. [Did you even realize that when you argue that gravity maintains the temperature differential, it is in fact you who are violating the 2nd Law of Thermodynamics?] The misapplication of the laws of thermodynamics where they do not apply (i.e. a system that is not in thermodynamic equilibrium) is where people often go wrong here. That, and trying to over-simplistically apply basic theories and laws (PV=rRT, etc.) without considering all of the interactions and ramifications. In particular, the system is greatly complicated by quantum mechanics, and the fact that the substances involved may be transparent or opaque to various frequencies of radiation. The system is just far, far more complex than your simple model allows, and as such your simple model is incapable of adequately describing or bounding the system. I suggest you study the facts behind radiation (at the molecular level) in detail before proceeding further with your erroneous train of thought.
78633. damorbel at 01:08 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re #1093 Tom Curtis you write:- "I did not mention energy transfer from the upper troposphere to the surface." If a temperature rise is to take place, from any cause, GHE or whatever, there must be an energy source. If it is CO2 in the upper atmosphere producing 'back radiation' that warms the surface, don't you agree that the GHG-caused-back-radiation must be some sort of energy source? You also write:- "In fact you could develop a model of the greenhouse effect in which all energy transfers within the atmosphere are convective" This unlikely, gas flow surely dominates but there is plenty of gas flow that is not convective; surely surface winds play an even more important role? To restrict your analysis to convection is going rather too far I suggest; how else, apart from ocean currents, is thermal energy going to get from the tropics to the poles? You also write:- "But introducing more CO2 to the atmosphere temporarily slows the rate at which energy leaves the atmosphere". Sorry but I cannot see how this can be the case. CO2 is a powerful radiator of thermal energy and on Earth CO2 is always warmer than deep space, even Fourier when writing about heat transfer recognised that is transferred in the direction of hot to cold, so CO2 is always going to absorb heat from the warm atmosphere, both by absorbing radiation and molecular collision so that it, together with the other GHGs, cools the planet very effectively by radiating to deep space. You argue :- "if you double the CO2 content, atmospheric radiation from lower in the atmosphere that formerly made it to space will be absorbed by the additional CO2 higher in the atmosphere." Indeed the change in height does change the radiation temperature by perhaps a few degrees but this only makes a small difference because the radiation to 2.7K (deep space) is for a temperature difference of about 200K (raised to the 4th power don't forget!); the few degrees change arising from height difference will have only a tiny effect. Also the higher effective radiation level means the radiating gas has a lower density so it cannot absorb all the radiation coming from below, some radiation will pass straight through without being reabsorbed by the upper levels because the gas density is dropping.
78634. Tom Curtis at 00:11 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Damorbel @1085, I did not mention energy transfer from the upper troposphere to the surface. In fact you could develop a model of the greenhouse effect in which all energy transfers within the atmosphere are convective. In that purely convective model of heat transfer within the atmosphere, there is no energy transfer from the upper troposphere to the surface. Never-the-less there is a greenhouse effect, which differs minimally from the real greenhouse effect. In such a model, the Earth's surface is warmed entirely by the Sun. But introducing more CO2 to the atmosphere temporarily slows the rate at which energy leaves the atmosphere. That creates an imbalance between incoming and outgoing energy, which must be stored somewhere and is stored as additional heat. Once enough heat is stored, the energy balance is restored, and all energy lost (or gained) is matched by energy gained (or lost) meaning the stored heat remains constant. Consider a bath tub, with a tap which lets water in, and another tap on the drain which can control the rate at which water goes out. If you turn the inlet tap on full, and the outlet tap on full, the water level of the bath will be constant. If you then half close the outlet tap, the water level in the bath will rise, even though no water flows back up the outlet pipe into the bath. This is exactly analogous to how the greenhouse effect works, and your objection is equivalent to a know-it-all on the side lines saying you can't raise the water level by closing the outlet tap. Your further claim that increasing the CO2 content of the atmosphere will increase the radiation to space assumes that energy radiated at a lower level in the atmosphere is never absorbed by CO2 at a higher level in the atmosphere. If you do not make that transparently false assumption, it becomes obvious that if you double the CO2 content, atmospheric radiation from lower in the atmosphere that formerly made it to space will be absorbed by the additional CO2 higher in the atmosphere. It will then be reradiated, but because it is reradiated by a higher and hence colder gass, it will emit less energy to space. I note that Sphaerica's and Dikran's post above more than adequately cover your other errors. As they note, you have been fully rebutted on these points many times and at length in this thread. Consequently I know there is no point in debate with you. I have responded twice now so that any late comers to this thread have a clear statement of the nature of your errors, but will not respond further. As you obviously have nothing new to add, nor any desire to learn, may I suggest you take to heart the moderator's prior direction to you.
78635. damorbel at 00:02 AM on 24 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re #1088 Sphaerica you write:- "While it is true that the measured pressure is higher closer to the ground... it stays that way. The pressure is not changing. To increase the temperature, you must compress the gas further. This clearly is not happening." As you decend through the atmosphere the pressure rises and the temperature rises. This is quite different from the bicycle pump, diesel engine etc. With the bicycle pump the ambient pressure remains the same so its temperature does not change, so the heat in the pump is tranferred into the ambient (thus the unchanging) temperature. The case of the atmosphere is quite different in that all the air at a given altitude heats up as you change that altitude, this means that the ambient temperature is changing at the same time, thus quite different from the bicycle pump example. It is a fact that, apart from wind blowing the air about a bit, the temperature gradient in the troposphere (not the absolute temperature!) is uniform over the entire globe because the force of gravity is, more or less, uniform also.
78636. Dikran Marsupial at 23:55 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       damorbel wrote: "I suggest that, from this argument, you would also accept that the 'net' transfer is from the warmer to the colder part of the atmosphere and thus it is the colder part that tends to be heated by the warmer surface." Yes, of course it is, and that is completely compatible with the commonly accepted physics of the GHE. BTW, your putting 'net' in quote strongly suggests you don't understand the reason it is there. It is a perfectly standard term, and it's meaning is key to your misunderstanding. "The logic of this is clear, CO2 in the atmosphere indeed radiates heat to deep space, cooling the planet down from the heating effect of the Sun" No, that does not follow logically. The CO2 in the amtosphere prevents heat from being radiated directly into space from the surface. Instead heat is only radiated to space from the upper trophosphere. The upper trophosphere is cooler than the surface, so there is less heat to radiate. Hence the more CO2, the higher in the trophosphere the radiating layer becomes, the colder this radiating layer is and the less heat that is radiated, not more. As for pressure gradients, I suggest we deal with the major flaw in your reasoning before getting on to more subtle points.
78637. damorbel at 23:42 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re #1087 Sphaerica you write:- "In answer to all of your questions about net heat flow." I did not mention 'Net' heat flow on #1086. In thermodynamics there is no such thing as "net heat flow". Heat flow, Net or otherwise is a concept belonging to the caloric theory of heat, a theory not accepted since about 1845 following the work of James Joule on the conservation of energy. I suggest that, from this argument, you would also accept that the 'net' transfer is from the warmer to the colder part of the atmosphere and thus it is the colder part that tends to be heated by the warmer surface. The logic of this is clear, CO2 in the atmosphere indeed radiates heat to deep space, cooling the planet down from the heating effect of the Sun - more CO2 makes for a greater cooling effect by re-radiating the ('net) heat transferring from the surface by convection, evaporation (and condensation) of water, surface radiation, hurricanes etc., etc. PS I can see nothing in your diagram that shows a warming effect on the surface, thare are no temperatures to be seen, it is not possible to argue for a warming effect without atleast two temperatures.
78638. DSL at 23:30 PM on 23 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       In other news, "During the first three weeks of July, 12 weather stations have recorded all-time daytime highs. But 93 weather stations have seen their all-time warmest nighttime temperatures." Meanwhile, the ongoing saga of Damorbel's refusal to accept the existence of the GHE continues . . .
78639. damorbel at 23:27 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re #1086 Dikran Marsupial you write:- "The law of heat transfer says that the NET flow of energy is from hot to cold. It does not say that no energy is transfered from the colder object to the warmer, just that the flow of energy in the other direction will be larger." I suggest that, from this argument, you would also accept that the 'net' transfer is from the warmer to the colder part of the atmosphere and thus it is the colder part that tends to be heated by the warmer surface. The logic of this is clear, CO2 in the atmosphere indeed radiates heat to deep space, cooling the planet down from the heating effect of the Sun - more CO2 makes for a greater cooling effect by re-radiating the ('net) heat transferring from the surface by convection, evaporation (and condensation) of water, surface radiation, hurricanes etc., etc. PS I would like to know what you think of the theory that the pressure gradient in the atmosphere results in a temperature gradient.
78640. Dikran Marsupial at 23:15 PM on 23 July 2011
       OA not OK part 9: Henry the 8th I was (*)
       Ken wrote "Well - how can we??" (i) why not wait for the next article in the series (ii) the mass balance argument shows beyond doubt that the natural environment is a net carbon sink, and has been discussed many times on SkS this article also written by Doug Your comment on the style of Doug et al.'s contribution is rather churlish. A lot of effort has gone into these posts, and just becuase they are not tailored specifically to your requirements does not mean they are not suitable for the interested layman. Sadly it is a shame when eminent scientists like Dyson make such criticisms of science beyond their area of genuine expertise. It is generally an indication of Dunning-Kruger syndrome. Do you agree with Dyson that GCMs do a good job of modelling the fluid motion of the atmosphere and oceans?
78641. Ken Lambert at 22:58 PM on 23 July 2011
       OA not OK part 9: Henry the 8th I was (*)
       Doug Mackie Original Post #9 "How can we be sure that ocean acidification is caused by CO2 in the atmosphere? That is, how do we know that the extra CO2 in the atmosphere is not coming from a natural warming of the ocean?" Well - how can we?? Forgive my ignorance of higher chemistry - but do we really need 9+ posts to get a result on the subject of ocean acidification? I have tried to follow through some of your earlier posts -and they seem to be a set of draft lecture notes for a graduate course. Now that is fine in itself - but some editing and a set of conclusions would be in order for the interested layman. As a separate point - oceanic biological processes are mentioned above. It has been a criticism of others - Freeman Dyson for example - that biological and plant processes are not part of any of Hansen's AGW modelling (and most if not all other GCM) and are probably very significant players.
78642. Bob Lacatena at 22:43 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       1085, damorbel, Concerning gravity, work is only done when the pressure is changed. While it is true that the measured pressure is higher closer to the ground... it stays that way. The pressure is not changing. To increase the temperature, you must compress the gas further. This clearly is not happening. You say:

       According to thermodynamic laws this temperature gradient is sustained by the pressure gradient.

       What does this statement mean? That a gas under pressure cannot cool? Think about it. [Hint #1: There is no such statement or law in Thermodynamics, that a temperature gradient is sustained by a pressure gradient. This is an inference arrived at by misapplying the Laws of Thermodynamics.] [Hint #2: The Laws of Thermodynamics apply specifically to bodies that are in Thermodynamic Equilibrium. A non-homogeneous atmosphere with a temperature and pressure gradient is clearly not a single body in Thermodynamic Equilibrium, so the Laws simply cannot be applied in a simple, single-minded fashion.]
78643. Eric the Red at 22:33 PM on 23 July 2011
       It's Pacific Decadal Oscillation
       Tom, You seem to be arguing for a step-like shift, whereas I was claiming a more gradual change. Instead of a jump around 1977, the change would slowly increase to a maximum around the trasition year, and slowly subside. If you plot the 5-year moving average for ENSO, the value rises steeply from 1975-1983, crossing zero in 1979. Hence, I would expect the greatest change over that interval. Currently, the moving average is falling, and crossed zero in 2009. We have yet to see if a repeat of the 1940s will occur. Once again, long term, the effects will cancel. As I stated previously, the 130-year near-linear trend is 0.6C / century, with early 2011 CRU data falling slightly below the trend line. I see no reason to deviate from this trend. Remember, an exponential rise in CO2 leads to a linear increase in temperature. Atmospheric CO2 concentrations have not kept pace with the expponential rise recently, so I see no reason for an increase in the temperature trend. Using a shorter time frame to determine a long-term trend may not be the best. Therefore, I think you estimate of 1.56 C by the century is high.
78644. Jeff T at 22:30 PM on 23 July 2011
       OA not OK part 8: 170 to 1
       Doug, please read comment 8 (14:44 PM) carefully. I'm a different Jeff. I studied what you wrote; I'd like to understand it; but I don't. Generally, one needs four equations to solve for four coupled parameters. Sarah and I are the only non-authors to make substantive comments. Do you really conclude from such a small sample that everyone else understood the post? I don't know what CT and AT are. Sarah, if the species ratios are more important than concentrations (for the health of corals or clams, say), it would help a lot for the post to explain that. The equation for water at the end of comment 9 (15:02 PM) isn't sufficient; water plus CO2 doesn't produce pH=8.
78645. Bob Lacatena at 22:27 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       1085, damorbel, In answer to all of your questions about net heat flow, please refer to the following simplified diagram of radiation exchange between the surface of the earth, the atmosphere, and the sun. The atmosphere (blue) is transparent to visible light (yellow) from the sun. This warms the surface (+4). The surface emits (according to its temperature of 5) in wavelengths which pass through the atmosphere into space (-3), losing that heat, and in wavelengths which are absorbed by the atmosphere (2). The atmosphere emits (according to its temperature of 2) equally in all directions, which means some heads into space and some back down. Thus, the temperature of the surface is 5 (4 from the sun, plus 1 from the atmosphere). The temperature of the atmosphere is 2 (from the surface). The planet gains and loses 5 at all times. The atmosphere gains and loses 2 at all times. Space gains and loses 4 at all times. Everything nets to zero. There is no energy created or lost. The 1st Law of Thermodynamics is never violated. Every net transfer (which is the only actual restriction) is warm to cold. The 2nd Law of Thermodynamics is never violated.
78646. Bob Lacatena at 22:05 PM on 23 July 2011
       Websites for Watching the Arctic Sea Ice Melt
       Looks like we just lost North Pole Cam 2 to a melt pond as well:
78647. Dikran Marsupial at 22:03 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       damorbel I am astonished that this point is still being debated here, given that the questions you raise have already been answered repeatedly. The law of heat transfer says that the NET flow of energy is from hot to cold. It does not say that no energy is transfered from the colder object to the warmer, just that the flow of energy in the other direction will be larger. Thus the questions are not valid as they are based on at least one fundamental misunderstanding of thermodynamics. BTW the GHE is accepted already. The fact that you are at odds with the vast majority of scientists on this one ought to suggest to you that perhaps the problem is with your understanding of the physics rather than with the physics itself.
78648. damorbel at 21:42 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Re #1084 Tom Curtis you write:- "The surface temperature at the normal CO2 level is set by the intersect of the lapse rate with the effective altitude of radiation at the equilibrium temperature for that altitude." You argue here that the surface temperature is governed by the TOA temperature, the '2nd Law' argument says that the thin, cold upper atmosphere that is losing lots of radiation to deep space is quite incapable of transferring any significant quantity of thermal energy to the warm, dense surface. The simple questions are 1/ 'Where does this energy come from'? 2/ How can a cold layer with a density about a tenth of the surface value possibly raise the surface temperature by even a small amount. The laws of heat transfer say that heat energy goes only from the hot surface to the tropopause where it is further radiated into deep space. These are valid questions; if the GHE is to be accepted valid answers to theses questions are needed also. Further you write:- "In exactly the same manner, gravity currently holds the pressure of the atmosphere, but does not increase it. Therefore it does no work and cannot replace the energy that escapes to space by radiation." This isn't the whole story because the pressure increases with depth, contrary to your claim that it doesn't change. It is gravity that causes the pressure gradient. According to thermodynamic laws this temperature gradient is sustained by the pressure gradient. Your example of a bicycle tire is not valid because there is no pressure gradient in a tire. The temperature change in the tire you note dies away because the pressure gradient is supported by the tire walls and not the gas in the tire.
78649. Tom Curtis at 20:45 PM on 23 July 2011
       It's Pacific Decadal Oscillation
       Eric the Red @130, you will note that I said, and that you have now agreed that:

       " if you have a period of predominantly La Ninas and follow with a period of predominantly El Ninos, in a period of no underlying trend, in the immediate period of the transition that will introduce a spurious trend to global mean temperatures. But outside of any interval that ranges across the point of transition, that change will introduce no trend to the series."

       (Emphasis added) The interval from 1977 (chosen because it was a high value for the period) to 2001 (chosen because Trenberth claims 25 years is the minimal period for a significant effect) follows after the end of the period of frequent La Ninas that occurred during the 60's and early 70's. It includes no transition from frequent La Ninas to frequent El Ninos, and included no transition from negative to positive PDO phase. Therefore on the principle quoted above, neither ENSO nor PDO have introduced a trend to that period. Never-the-less the trend over that interval (HadCRUT3) is 0.156 degrees C per decade. Further, the period 1951-1975 does not include a transition from frequent El Ninos to frequent La Ninas, and has a Negative PDO phase throughout. Therefore on the quoted principle, these ocean fluctuations have introduced no trends to that period, and hence the negative trend over that interval (see graph in 131) is not explained by ENSO states or the PDO. Finally, even if we are undergoing a transition between frequent El Ninos to frequent La Ninas, and/or from positive to negative phase PDO, on the quoted principle that would at most introduce a spurious reduction of the trend in the immediate decade of the transition. Over the following decades, and until the next transition (which would introduce a temporary spurious increase to the trend), they cannot be expected to effect the trend at all. Consequently we would predict a resumption of the preceding trend, and hence have no reason to expect ENSO or the PDO to result in a reduce trend for a sustained period into the future. I think these three points follow straight forwardly from the quoted principle, which as I have said follows straight forwardly from the discussion in 109, and to which you have agreed. Given that, why would we not be predicting an increase in temperature by at least 1.56 degrees by the end of this century, and far probably more because of the increasing GHG forcing?
78650. Tom Curtis at 20:13 PM on 23 July 2011
       2nd law of thermodynamics contradicts greenhouse theory
       damorbel @1083, the diagram in 1080 shows three horizontal lines, H, H + delta H, and the Tropopause. It shows two diagonal lines, CO2 and 2*CO2. The line H represents the effective altitude of radiation with the initial CO2 concentration. The equilibrium temperature at that altitude is set by the energy balance such that the Outgoing Longwave Radiation (OLR) equals the Incoming solar radiation times the planetary albedo. The surface temperature at the normal CO2 level is set by the intersect of the lapse rate with the effective altitude of radiation at the equilibrium temperature for that altitude. If you double CO2, the effective altitude of radiation is increased. In the diagram the new effective altitude of radiation is represented by H + delta H. The equilibrium temperature at this new altitude is approximately the same as the original equilibrium temperature because incoming solar radiation and albedo have not changed (but see below). Therefore the surface temperature is still set by the intersect of the lapse rate with the new altitude of effective radiation at the equilibrium temperature. As the diagram shows, this requires that the intersect of the lapse rate with the surface shift to the right, ie, that the surface temperature increase. Of course, in real life there will be feed back effects that may change albedo, and may change the lapse rate, as well as introducing increased GHG concentrations (water vapour) to the atmosphere. These complexities do effect the final result. Indeed, in the most likely case given the evidence, they increase the change in surface temperature by a factor of 2.5. But they do not change the fundamental principles involved. Regarding the compression effect, it was once fundamental to the Earth's climate, but is no longer. To illustrate this, consider the example of pumping up a bicycle tire. As we well know, doing so raised the temperature of the air in the tire. But once we stop pumping, the extra heat dissipates even though the air remains compressed. Indeed, if we leave the bike for a few hours, the air temperature inside the tire will be the same as the ambient air temperature. The reason for this is that so long as the wall of the tire is merely holding the pressure instead of increasing it, it does no work. And because it does no work, it introduces no new energy into the air to replace any that escapes to the environment by conduction or radiation. In exactly the same manner, gravity currently holds the pressure of the atmosphere, but does not increase it. Therefore it does no work and cannot replace the energy that escapes to space by radiation. In the very distant past the Earth's gravitational field created the compression in the first place in a process astronomers call "accretion". The amount of energy released by this compression left the Earth completely molten, but as William Thompson, Lord Kelvin showed over a hundred years ago, it only takes from a hundred thousand to ten million years for all that energy to dissipate. Consequently, from long before any life evolved on Earth, almost all energy on Earth has come from the sun, and the Earth has remained molten only because of the radioactive elements in its core.

Prev  1565  1566  1567  1568  1569  1570  1571  1572  1573  1574  1575  1576  1577  1578  1579  1580  Next