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Post by ron on Feb 6, 2009 6:48:35 GMT
What I am saying is that we may be inside an oscillation where the temperatures that we are measuring are immaterial as they are chaotic with or without variations in the sun or levels of CO2, just as the sudden change in the arctic was not created by any sudden change in CO2 or solar activity. It just "is." Why are we in a long term warming trend? Because we are. We're inside of a cycle we cannot see. Perhaps. Why are there short term increases in warmth? Are they due to the sun's cycles or are they just a piece of the larger cycle that we're in? That's a good question. Perhaps there's a connection, perhaps it's the only reason. Perhaps part of the chaotic nature of the world will be exacerbated in some ways we will never be able to understand or model without affecting the overall health or balance of the planet, or perhaps they can cause wild swings, like in the arctic, as the world continues to try to balance out hot vs cold. Just because our world is chaotic to us in our frame of reference doesn't mean there isn't a cycle going on with all of its minor chaotic variation that was set in motion 100,000 years ago. Or not. Of course in the end the heat is coming primarily from the sun, so to the extent that you want to find the world's original calories, we can always say it's the sun's fault. All of which doesn't address my original questions! LOL If creating CO2 at the expense of O2 is neutral, and if not, why not? If one type of energy absorption is saturated as O2 seems to be, why can't CO2 reach a saturation point? If it is more complex than that, with O3 coming into play due to some impact on the O2, such as less O2 leads to less generation of O3, I'm open to learning about that, too.
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Post by ron on Feb 6, 2009 6:59:35 GMT
I guess I just don't see it as "either it is AGW or solar." IF the Solar theory is as hard to prove/disprove as AGW, then nobody will ever win. If we find out that it isn't just the sun then all arguments against a fallacious (if it is) AGW argument are lost.
But if the public can be made to understand that the science is NOT settled on the vast majority of the earth's climate issues, if that's true, which I believe it to be, that's a huge step in the right direction. If the public can be made to understand that the planet is warming anyway, and all of the ills predicted are going to happen anyway it's just a matter of a difference in time, perhaps the panic will go away. Or perhaps we can get people to stop building on seashores and expecting help when the waters come.
Besides, if we really want or need to cool the earth, it is a really REALLY easy thing to do, compared with reducing CO2 output. We'd need to shield somewhere between 2/10ths of 1% and 1% of the sun's enery from hitting the earth. I'm sure we could come up with a relatively easy and cost effective way of doing that.
It's a lot harder to warm a cooling planet than it is to cool an overheated planet.
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Post by duwayne on Feb 6, 2009 15:35:46 GMT
I guess I just don't see it as "either it is AGW or solar." IF the Solar theory is as hard to prove/disprove as AGW, then nobody will ever win. If we find out that it isn't just the sun then all arguments against a fallacious (if it is) AGW argument are lost. But if the public can be made to understand that the science is NOT settled on the vast majority of the earth's climate issues, if that's true, which I believe it to be, that's a huge step in the right direction. If the public can be made to understand that the planet is warming anyway, and all of the ills predicted are going to happen anyway it's just a matter of a difference in time, perhaps the panic will go away. Or perhaps we can get people to stop building on seashores and expecting help when the waters come. Besides, if we really want or need to cool the earth, it is a really REALLY easy thing to do, compared with reducing CO2 output. We'd need to shield somewhere between 2/10ths of 1% and 1% of the sun's enery from hitting the earth. I'm sure we could come up with a relatively easy and cost effective way of doing that. It's a lot harder to warm a cooling planet than it is to cool an overheated planet. Well said. On your point about cost effective ways of cooling, most everyone agrees that small concentrations of aerosols can reduce temperatures 1 or 2 degrees. This would offset the warming now projected by NOAA and presumably IPCC. There are several proposals or how to do this for a few billion dollars per year or less than 1% of the US stimulus package. Why would anyone opt for wrecking the world economy through cap and trade or whatever?
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Post by donmartin on Feb 7, 2009 7:26:33 GMT
Why is the atmosphere of Mars 95% carbon dioxide?
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Post by kiwistonewall on Feb 7, 2009 10:40:56 GMT
now that is intriguing Ron, but I'll answer your Question first. CO2 is a heavier molecule that O2 or N2, and Mars, being smaller than Earth, does not have high enough gravity to hold on to the lighter molecules.
What is intriguing is this: Mars is 95% CO2: but has a comparatively large amount of carbon dioxide in the Martian atmosphere – 9 times more overall than is contained in Earth's much thicker atmosphere. So while it has only about 1% as much atmosphere as Earth, it is nearly all CO2.
So any Infra red heat leaving the Martian Surface is facing an atmosphere with 9x as many CO2 molecules (at least in the lower atmosphere)
Yet, and this is very interesting, the Greenhouse effect on Mars is very small, even with 9 times as much CO2 as on Earth. The Estimated Greenhouse warming with 9 times the Earth's CO2 is only 12 degrees F.
The argument that the Martian atmosphere is thin is not relevant to the Greenhouse effect. On Earth, the atmosphere is mainly O2 & N2 and these have no IR absorption.
True, Mars is further away from the Sun, but with 9 times the CO2 one would expect a hot planet if CO2 was that important!
What is missing on Mars is the water vapour which is Earth's important GHG.
But Mars shows how unreal the while "runaway" GHG argument is.
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Post by steve on Feb 7, 2009 15:01:46 GMT
Off top of head...
Earth's greenhouse effect supposedly adds about 32C to the temperature.
About 1/3 of this is due to CO2 - so about 10C due to CO2.
9 times CO2 is approximately 3 doublings. Roughly, this would be expected to add about 3C to the warming on earth (before feedbacks).
So I'd expect Mars to be about 13C warmer than it would be without a CO2 atmosphere.
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Post by jimcripwell on Feb 7, 2009 18:10:43 GMT
steve writes "Earth's greenhouse effect supposedly adds about 32C to the temperature.
About 1/3 of this is due to CO2 - so about 10C due to CO2."
Do you have a reference for the value of 1/3 for the contribution of CO2? I have searched the literature for such a figure, and have found values of greater than 50% to less than 3%. I have contemplated exactly how I would go about calculating such a number, and have not found an idea that would satisfy me. It must involve the distribution of the absolute humidity for the whole globe, plus the distribution of some sort for the temperature of the earth where the different absolute humidities exist. Water vapor, by definition, cannot have a radiative forcing value. Any help would be gratefully received. TIA.
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Post by steve on Feb 9, 2009 11:18:37 GMT
Jim, I based the 1/3 on the fact that current models predict a water vapour related feedback of 2-3 times. Also it fits this finger-in-the-air experiment: www.realclimate.org/index.php?p=142The point is that we're looking at a greenhouse effect on Mars of substantially less than 30C.
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Post by jimcripwell on Feb 9, 2009 11:54:50 GMT
steve writes "I based the 1/3 on the fact that current models predict a water vapour related feedback of 2-3 times."
Thanks, steve. Let me be quite clear. You have no peer reviewed referenced for you claim that CO2 produces 1/3 of the greenhouse effect. Is this correct?
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Post by tallbloke on Feb 9, 2009 12:20:20 GMT
steve writes "I based the 1/3 on the fact that current models predict a water vapour related feedback of 2-3 times." Thanks, steve. Let me be quite clear. You have no peer reviewed referenced for you claim that CO2 produces 1/3 of the greenhouse effect. Is this correct? The realclimate article and following comments Steve links above seems to put it at a lot less.
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Post by steve on Feb 9, 2009 12:36:09 GMT
steve writes "I based the 1/3 on the fact that current models predict a water vapour related feedback of 2-3 times." Thanks, steve. Let me be quite clear. You have no peer reviewed referenced for you claim that CO2 produces 1/3 of the greenhouse effect. Is this correct? It was an off-top-of-head post. 1/3 is a guesstimate. For the 1/3 number I was thinking about much of the work of Held and Soden in reviewing the different models. eg. arjournals.annualreviews.org/doi/abs/10.1146%2Fannurev.energy.25.1.441Strictly speaking this refers to the "enhanced greenhouse effect". ie. the extra warming caused by the extra anthropogenic CO2. Off-top-of-head-again. Without water vapour, the CO2 in earth's atmosphere would at a guess warm it by quite a bit more than the 10C I suggested because the warming of the CO2 and the H20 is not additive. Anyone any good with MODTRAN?
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Post by tallbloke on Feb 9, 2009 13:32:15 GMT
Or alternatively, the water vapour would heat the earth only slightly less with no co2 in the atmosphere.
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Post by jimcripwell on Feb 9, 2009 14:44:17 GMT
steve writes "Anyone any good with MODTRAN? "
Models are useless, steve. Unless we have some hard, measured, independently replicated experimental data, it is not physics, and the numbers are absolutely meaningless.
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Post by steve on Feb 9, 2009 15:17:19 GMT
My reply was to refute this post by Kiwistonewall. If CO2 were as important as climate scientists think, and if CO2 were to have as strong effect on Mars, Mars would be roughly 12C warmer than it would be without its greenhouse effect. We would not expect a "hot" planet. But I'm wrong! This paper suggests that the Mars greenhouse effect is about 4 or 5C. Possibly the thinness of the atmosphere is important. For example, pressure broadening is often cited as strengthening the greenhouse effect. Or possibly water vapour does indeed have magical properties that CO2 is not endowed with. www.agu.org/pubs/crossref/2005.../2004JE002306.shtmlRadiative-convective model of warming Mars with artificial greenhouse gases Margarita M. Marinova et al JGR Planets 2005
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Post by crakar24 on Feb 10, 2009 4:48:25 GMT
Well, well, well a couple of days ago i was lambasted by someone for asking about the historical high levels of C02 on Earth and thier effects on the climate and was told we might as well be talking about a different planet and here we are now doing just that, where is that pesky poster when you need him?
Seriously if water vapour is the missing ingredient to the martian atmosphere stopping it from getting any warmer then maybe someone can explain why Venus has about 97% C02 and no water and yet is very very hot, and yes i know it is closer to the sun but hey whats the sun got to do with AGW.
I suspect C02 behaves much the same way on Mars as it does here, therefore there will be only the 3 very small absorbtion bands across the IR frequency spectrum. With no water vapour to mop up the rest, it is obvious that C02 plays a very minor role on Mars, ergo the same goes on Earth.
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