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Post by steve on Apr 2, 2009 8:31:19 GMT
1. Radiation is a property of ALL matter. So the greenhouse effect works without greenhouse gases!! (FACT) Yes, if there were just, say, O2 in the atmosphere then there would be a greenhouse effect due to the microwave absorption/emission of O2. But at temperatures in the range of those experienced in earth's atmosphere the effect would be extremely weak because the emissivity/absorptivity is low at the wavelengths of radiation emitted by earth's surface. ie. over 99% of the radiation would escape directly to space. No you are quite wrong here, and a basic google for radiation transfer equations will prove it. Radiation transfer formulae also depend on emissivity, as only idealised black bodies have emissivity of one resulting in the idealised curve you showed above. The formula is radiation = emissivity times Stefan-Boltzmann's constant times Temperature to the power 4 Furthermore, the emissivity is dependent on the wavelength. That is an inconsistent set of statements. You state that there is radiation from you towards the bar heater (correct) but you state that it "can't be observed". If it can't be observed then how do you know it is there? If it is irrelevant then are you saying that the energy that you are emitting disappears? Or are you saying that there is some sort of quantum effect whereby the bar heater increases its radiation towards you to exactly match the radiation that you are sending towards it. In reality, if you have two bodies at different temperatures, then they both radiate towards each other, but the warmer body radiates more such that the net flow of heat (which what the laws of thermodynamics is all about) is toward the cooler body. Whether that is relevant given that the knowledge of the concept has been improved and refined over the years, the basics underlying the 2nd law of thermodynamics and the first exposition of the greenhouse effect were published in the same year (1824) by Carnot and Rutherford respectively. Now all you have to do is convince Richard Lindzen, Roy Spencer, John Christie, Pat Michaels and a few others and you're home and dry.
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Post by kiwistonewall on Apr 2, 2009 12:07:40 GMT
Steve, you are being disingenuous,
the fact is that concentration of CO2 doesn't appear in the formula.
There are a lot more terms than just T (Obviously) but the greenhouse effect is a function of temperature, and has NOTHING to do with "greenhouse gases" as such. Gases are close to ideal blackbodies.
The issue is that a non CO2/H20 atmosphere would show EXACTLY the same warming effect. The constitution of the gases is largely irrelevant.
Planets with atmospheres are warmer, planets with none are cooler. (or should we say - they both bake & freeze!)
Atmospheres slow day time warming, and slow nighttime cooling. Standard thermodynamics.
Greenhouse gases (like many folk today) are redundant! ;D
Parading off a list of names of those who believed in Phlogiston, all genuine experts of their day, wouldn't make that failed theory true. Experts are only experts of a tiny narrow field - and generally are unread and ignorant outside their specialties. Most just accept the 'status quo' - and don't rock the boat. Had the Phlogiston theory some political clout, the fathers of modern chemistry would have all been labeled 'Phlogiston deniers' - I used to teach my chemistry class the Phlogiston theory (and had them believing it!) just to teach them about the scientific method.
Truth is truth, no matter how many believe it. Science isn't democracy. Experts are constantly proved wrong. Even my thinking has only recently been clarified - and I do see clearly now!
The big lie is that the whole thing depends just on the greenhouse gases. That is total nonsense.
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Post by steve on Apr 2, 2009 15:37:15 GMT
Steve, you are being disingenuous, the fact is that concentration of CO2 doesn't appear in the formula. There are a lot more terms than just T (Obviously) but the greenhouse effect is a function of temperature, and has NOTHING to do with "greenhouse gases" as such. Gases are close to ideal blackbodies. No I am not being disingenuous. Gases are not close to ideal black bodies. That is why they have spectral lines. CO2 does appear in the formula in the emissivity term. Its emissivity is high at some wavelengths (such as 15 microns) and low at others. So Lindzen, Spencer and Christie who spend their lives studying the mid-troposphere; the latter two through measuring the radiation emitted by oxygen molecules and deriving temperature data from them are "unread and ignorant" with respect to the "greenhouse" effect. And do you think maybe that science might have moved on from the phlogistin days. Even the M-theorists accept they could be barking up the wrong tree because of the difficulty of running empirical tests. I'm spotting an attempt to switch things here. The "whole thing" doesn't depend "just" on the greenhouse gases so your "big lie" does not exist in any climate scientist's mind. Many things affect the earth's climate of which increasing amounts of greenhouse gases are one thing. Also, you have started out saying the greenhouse gases essentially have no significant effect (ie. an identical effect to the oxygen and nitrogen that comprise 96+% of the atmosphere). Now with your "just" you are leaving a gap for greenhouse gases having a role in addition to other climate phenomena.
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Post by gridley on Apr 2, 2009 15:39:32 GMT
Socold, showing a very poorly mixed gas does not make everything else well mixed.
You appear to contend that a 33% increase over ~180 years is critical, but that a 5% variation within a single month is irrelevant. How can a variation that is three hundred times greater than the mean rate of change not effect behavior?
I will concede that the single graphic presented does not prove that such variations are the rule, or that the variable distribution is constant, but can you (or anyone) provide any similar CO2 concentration maps, at any level of the atmosphere, at any point or period in time, which show that 5% is a transient or unusual variation, or that the areas of high concentration are significantly different from those shown?
Please remember that you're asserting that a 0.015% monthly increase in a gas that is 0.03% of the atmosphere is the dominant driver of temperature change when you are considering the impact of a 5% regional variation.
In other words, if we take 20 years as a period where environmental change can be detected, a 3.7% change in CO2 concentration has a measurable effect, but a 5% change in CO2 concentration does not.
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Post by icefisher on Apr 2, 2009 15:41:28 GMT
1. Radiation is a property of ALL matter. So the greenhouse effect works without greenhouse gases!! (FACT) Yes, if there were just, say, O2 in the atmosphere then there would be a greenhouse effect due to the microwave absorption/emission of O2. But at temperatures in the range of those experienced in earth's atmosphere the effect would be extremely weak because the emissivity/absorptivity is low at the wavelengths of radiation emitted by earth's surface. ie. over 99% of the radiation would escape directly to space. Steve, all emitters that emit at 255k are extremely weak! CO2 in the lower atmosphere is emitting at the same rate as the O2. . . .cause its the same temperature. Now I am not going to go so far to say that massive changes in the composition of the atmosphere is not going to change climate. The only thing I am saying is they grossly overexaggerated the role of CO2. Whats happened here happens almost everyday in some industry. Some guy who thinks he is smart looks at a recent trend and thinks he understands it. The classic example is a developer that gets greedy in an up market. He starts selling banks on projects with pie in the sky projections of future revenues. The market doesn't continue to soar and the bank gets left holding the bag. . . .which is you and me. Banks are easy targets because loan officers aren't spending their own money. This project is major bigtime sideways. It isn't going to right itself. Since we are early in the failure of the models you can fairly safely bet we have not yet seen the worst of it. You can also bet that guys like Hansen will never admit it. They will try to sell you the pig in a poke till their last breath. It doesn't even matter what they believe anymore, its now about their own skin.
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Post by steve on Apr 2, 2009 15:48:45 GMT
gridley,
When we say a gas is "well mixed" it means that a large emission of the gas at one point of the atmosphere will soon increase the *average* concentrations across the planet. It doesn't necessarily mean the concentrations everywhere are the same.
CO2 is measured in very many places in the atmosphere in addition to Mauna Loa, and all the measurements are consistent with each other in showing an on average increase of 1-2 parts per million per year, and also shows a slight delay between northern and sothern hemisphere (because most emission is in the northern hemisphere).
The enhanced greenhouse effect is based on the average levels of CO2 going up everywhere in the atmosphere. Random fluctuations will average out. Areas of high CO2 eg. due to cities will get even higher CO2. There will be a few small areas where CO2 might drop or have an extra rise (eg. due to a cut or increase in fossil fuel use), but these areas are likely to be insignificantly small.
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Post by steve on Apr 2, 2009 15:56:50 GMT
Yes, if there were just, say, O2 in the atmosphere then there would be a greenhouse effect due to the microwave absorption/emission of O2. But at temperatures in the range of those experienced in earth's atmosphere the effect would be extremely weak because the emissivity/absorptivity is low at the wavelengths of radiation emitted by earth's surface. ie. over 99% of the radiation would escape directly to space. Steve, all emitters that emit at 255k are extremely weak! CO2 in the lower atmosphere is emitting at the same rate as the O2. . . .cause its the same temperature. I'd ask for evidence of that but it doesn't exist. What you are saying strikes at the heart of the whole of modern physics. I'm not going as far as requiring "massive" changes. A 0.03% increase in CO2 will do me fine as counting as a significant change. Nope. The AGW hypothesis was born in 1896 and has survived numerous ups and downs in temperature.
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Post by gridley on Apr 2, 2009 15:58:17 GMT
gridley, When we say a gas is "well mixed" it means that a large emission of the gas at one point of the atmosphere will soon increase the *average* concentrations across the planet. It doesn't necessarily mean the concentrations everywhere are the same. CO2 is measured in very many places in the atmosphere in addition to Mauna Loa, and all the measurements are consistent with each other in showing an on average increase of 1-2 parts per million per year, and also shows a slight delay between northern and sothern hemisphere (because most emission is in the northern hemisphere). The enhanced greenhouse effect is based on the average levels of CO2 going up everywhere in the atmosphere. Random fluctuations will average out. Areas of high CO2 eg. due to cities will get even higher CO2. There will be a few small areas where CO2 might drop or have an extra rise (eg. due to a cut or increase in fossil fuel use), but these areas are likely to be insignificantly small. So you're saying, in a roundabout way, that the electrical analogue does not apply? For the mixing... I think we're going to have to agree to disagree. My field is admittedly mechanics, not thermo, fluids, or fuels, but I can think of no examples from my classes in those subjects where I could get away with calling 5% variations "well mixed", regardless of circumstances. Thank you for responding to my question about measurements of CO2, though I would still like a link to raw data or information on tolerances and instrument accuracy.
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Post by steve on Apr 2, 2009 17:03:15 GMT
gridley, When we say a gas is "well mixed" it means that a large emission of the gas at one point of the atmosphere will soon increase the *average* concentrations across the planet. It doesn't necessarily mean the concentrations everywhere are the same. CO2 is measured in very many places in the atmosphere in addition to Mauna Loa, and all the measurements are consistent with each other in showing an on average increase of 1-2 parts per million per year, and also shows a slight delay between northern and sothern hemisphere (because most emission is in the northern hemisphere). The enhanced greenhouse effect is based on the average levels of CO2 going up everywhere in the atmosphere. Random fluctuations will average out. Areas of high CO2 eg. due to cities will get even higher CO2. There will be a few small areas where CO2 might drop or have an extra rise (eg. due to a cut or increase in fossil fuel use), but these areas are likely to be insignificantly small. So you're saying, in a roundabout way, that the electrical analogue does not apply? For the mixing... I think we're going to have to agree to disagree. My field is admittedly mechanics, not thermo, fluids, or fuels, but I can think of no examples from my classes in those subjects where I could get away with calling 5% variations "well mixed", regardless of circumstances. Thank you for responding to my question about measurements of CO2, though I would still like a link to raw data or information on tolerances and instrument accuracy. I'm not that bothered about the term "well-mixed". What's important to me is that we know that an average 10% increase in CO2 at Mauna Loa would probably equate to an average of 10% increase at, say, sea level, 5km up and 10km up, in Iceland, Antarctica and the top of Kilimanjaro to name 3 places at random. This is different from, for example, water vapour where levels of water vapour drop rapidly with height, which is important when calculating the greenhouse. Had to search a bit for the "electrical analogue". In principle an area with lower than average greenhouse gases will "let out" more heat than an area with higher than average levels. The average amount of heat that needs to be let out is 235 Watts per metre squared. The change induced by CO2 is approximately 5.35 ln(C/Corig) where Corig is 280 parts per million. So current levels of 380ppm would cut the outgoing radiation by 1.6 Watts per metre squared. That's some info for you to play with the figures to see what effect variability might have, though variability in the vertical would also be relevant. This site seems to have a lot about CO2 measuring: www.esrl.noaa.gov/gmd/ccgg/carbontracker/index.htmlPerhaps you could download some of the Carbon Tracker output and calculate the forcing variability from it.
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Post by glc on Apr 2, 2009 18:59:19 GMT
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Post by socold on Apr 2, 2009 20:14:24 GMT
Socold, you said: "The atmosphere won't radiate in a black body curve, because the atmosphere is not a backbody. Greenhouse gases emit IR (by definition), other gases do not because they don't vibrate to interfere with the electromagnetic field to produce IR light." That is wrong - Now you are saying that the Sun doesn't give off any heat!!!! Yes, that is what you are saying. The Sun is a giant ball of gas, giving off the blackbody radiation appropriate for its temperature. I guess all the warming comes from CO2 and the Sun is unnecessary? ;D The Sun does approximate a blackbody. The Earth's atmosphere does not. See the Earth emission spectrum - it isn't a blackbody curve. Because the Earth is not a blackbody. Simple really.
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Post by jimg on Apr 2, 2009 20:32:22 GMT
Just curious glc, did you read it?
Is the argument you are defending, "Does the greenhouse effect exist?" or "Is CO2/AGW the primary driver of current climate"
In the former, obviously it does exist, the latter question is what is in dispute.
Excerpts: To briefly review: because water vapor, clouds, carbon dioxide, and methane in the atmosphere absorb and emit infrared radiation, the atmosphere stays warmer in the lower atmosphere and cooler in the upper atmosphere than it would otherwise be without the greenhouse effect.
------
In the case of the Earth, most sunlight is absorbed at the surface, which then heats and moistens the air above it. This solar heating causes the lower atmosphere to warm, and the greenhouse effect of the water vapor thus generated helps keep the lower atmosphere warm by reducing its rate of cooling. (Long before radiation can make the surface too warm, though, convective air currents kick in…e.g. thunderstorms…and transport much of the excess heat from the lower to the upper atmosphere. As a result, the lower atmosphere never gets as warm as the greenhouse effect ‘wants’ to make it.)
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Post by kiwistonewall on Apr 2, 2009 20:33:32 GMT
Material A at 25C is in equilibrium with material B at 25C.
Both have different black body (non ideal curves)-
Will one heat the other? NO. The shape of the curve is irrelevant.
Thermodynamics rules. (PS I agree with Roy Spencer's explanation. It is what I am saying.)
The atmosphere will be a greenhouse regardless of its bb curve shape. Read some good books (Like Radiative Processes in Astrophysics By George B. Rybicki, Alan P. Lightman)
The truth is that a lot of simplifications (lies to children!) have been spouted by the AGW movement to educate the masses. This leads to huge confusion amongst the scientific illiterate.
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Post by socold on Apr 2, 2009 20:56:12 GMT
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Post by socold on Apr 2, 2009 21:36:27 GMT
(PS I agree with Roy Spencer's explanation. It is what I am saying.) Oh really. You said"Any warmer area will transfer heat to a cooler area. There is NEVER the case of a cooler atmosphere passing heat energy to a warmer earth, which would contradict the laws of thermodynamics." Roy Spencer says"A second objection has to do with the Second Law of Thermodynamics. It is claimed that since the greenhouse effect depends partly upon cooler upper layers of the atmosphere emitting infrared radiation toward the warmer, lower layers of the atmosphere, that this violates the 2nd Law, which (roughly speaking) says that energy must flow from warmer objects to cooler objects, not the other way around. There are different ways to illustrate why this is not a valid objection." ---- I said"There is nowhere in that diagram that heat flows from a colder region to a warmer one. Heat flows from the warmer surface to the cooler atmosphere. The effect of co2 and water vapor in the atmosphere is to reduce that flow. The effect of reduced heat loss from the surface is that the surface warms." and: "Greenhouse gases warm the surface indirectly by reducing heat loss. Heat isn't transfered from the atmosphere to the surface." Roy Spencer says"the greenhouse blanket around the Earth is somewhat analogous to a real blanket, which we all know tends to hold heat in where it is being generated, and reduce its flow toward the colder surroundings. A blanket – real or greenhouse — doesn’t actually create the separation between hot and cold…it just reduces the rate at which energy is lost by the hot, and gained by the cold." So I guess me and him agree about how the greenhouse effect works. Just in case you missed it I already pointed this out long ago: "It's not the "AGW" theory of how the greenhouse effect works as even AGW skeptics like Lindzen, Spencer, McIntyre accept it. It's the mainstream science view of how the greenhouse effect works." You however disagree with Roy Spencer (and me) on multiple points: You said"There is no greenhouse effect (as proposed by climate "scientists") there is simply no physical basis for this." You said"The "real" greenhouse effect doesn't require "greenhouse" gases - in the same way a greenhouse doesn't require glass!" Roy Spencer says"because water vapor, clouds, carbon dioxide, and methane in the atmosphere absorb and emit infrared radiation, the atmosphere stays warmer in the lower atmosphere and cooler in the upper atmosphere than it would otherwise be without the greenhouse effect." ----- You said"Socold, The Earth's greenhouse works EXACTLY like a agricultural greenhouse. Neither work by IR re-radiation as believed by Arrhenius and others." Roy Spencer says"The processes involved in the atmospheric greenhouse effect are not the same as what happens in a real greenhouse." ------ You said"the problem with all models is that they assume a static grid, so nothing in the model is remotely realistic in terms of physics." Roy Spencer says"The greenhouse effect is supported by laboratory measurements of the radiative absorption properties of different gases, which when put into a radiative transfer model that conserves energy, and combined with convective overturning of the atmosphere in response to solar heating, results in a vertical temperature profile that looks very much like the one we observe in nature." ----- Roy Spencer sums up with"So, until someone comes along with another quantitative model that uses different physics to get as good a simulation of the vertical temperature profile of the atmosphere, I consider objections to the existence of the ‘greenhouse effect’ to be little more than hand waving." You say"I agree with Roy Spencer's explanation. It is what I am saying" Then stop hand waving.
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