Global Mean Temperature

[Lagboltz]

Saying somebody else believes something to be true is not the same as explaining what was asked.

2nd law says that flow from cold to hot is not possible without without external work being performed on the system.

so whats the external work ? and how does it allow CO2 to redirect energy that passes through it at near the speed of light ? I know that there are no swimming pools or hotplates out in the atmosphere so lets steer clear of them please.

I did explain things in great detail as it would in a textbook. It's only the hotplates that have relevance here. If Pale thinks there is no radiation and no photons between two hotplates at the same temperature, then he is rejecting fundamental laws of radiation physics. It's like trying to explain the orbits of planets to someone who doesn't believe in gravity.

Do you also believe radiation between two identical light bulbs cancel each other out and create a dark streak between them?

 

[dogtowner]

I did explain things in great detail as it would in a textbook. It's only the hotplates that have relevance here. If Pale thinks there is no radiation and no photons between two hotplates at the same temperature, then he is rejecting fundamental laws of radiation physics. It's like trying to explain the orbits of planets to someone who doesn't believe in gravity.

Do you also believe radiation between two identical light bulbs cancel each other out and create a dark streak between them?

two hotplates are both hot the issue is heat flowing from cooler to hotter.
enrrgy does not cancel see law 1.

 

[Lagboltz]

two hotplates are both hot the issue is heat flowing from cooler to hotter.
enrrgy does not cancel see law 1.

I don't think that's the issue. Right now the issue is not believing the laws of radiative thermodynamics. I have 6 references in posts 81 and 83 that says that bodies at the same temperature radiate to each other. (That is what my statements 1-3 mean.) Pale says there is no radiation to each other, in that the radiation cancels to zero. If there is no agreement on what is happening in an equilibrium state, how can a discussion proceed in the much more complex non-equilibrium states of the atmosphere.

If one body is hotter than the other, then the hotter one is radiating more energy than the colder one, so yes, the colder body receives more thermal energy than it radiates, and thereby grows warmer.

 

[dogtowner]

I don't think that's the issue. Right now the issue is not believing the laws of radiative thermodynamics. I have 6 references in posts 81 and 83 that says that bodies at the same temperature radiate to each other. (That is what my statements 1-3 mean.) Pale says there is no radiation to each other, in that the radiation cancels to zero. If there is no agreement on what is happening in an equilibrium state, how can a discussion proceed in the much more complex non-equilibrium states of the atmosphere.

If one body is hotter than the other, then the hotter one is radiating more energy than the colder one, so yes, the colder body receives more thermal energy than it radiates, and thereby grows warmer.

It is exactly the issue as you claim that a cooler CO2 can radiate energy back toward a hotter earth. This despite the 2nd Law of Thermodynamics without even considering that energy passes through CO2 at near the speed of light.

If you have an explanation as to how CO2 becomes the external work I'm all ears.

 

[Lagboltz]

It is exactly the issue as you claim that a cooler CO2 can radiate energy back toward a hotter earth.

... and the hotter earth radiates even more energy back to the cooler atmosphere.

You forgot that second part of the process.

This despite the 2nd Law of Thermodynamics without even considering that energy passes through CO2 at near the speed of light.

If you have an explanation as to how CO2 becomes the external work I'm all ears.

When you consider the second part, there is no net heat flow to the hotter earth, and no violation of the 2nd law.

 

[dogtowner]

... and the hotter earth radiates even more energy back to the cooler atmosphere.

You forgot that second part of the process.
When you consider the second part, there is no net heat flow to the hotter earth, and no violation of the 2nd law.

what second part ? the warmer earth radiates to the atmosphere which then has little choice but to release tht energy to a colder source like space.

now...

If you were to consider that there are other things up in the air that do not suffer the same constraints as CO2, H2O for example, then perhaps we can get somewhere. Remember that H2o has the unique ability to change it's form in the free atmosphere (external work ?) not to mention the fact that its FAR more prevalent.

 

[Lagboltz]

what second part ? the warmer earth radiates to the atmosphere which then has little choice but to release tht energy to a colder source like space.

Not exactly. The net effect is that the CO2 backradiation prevents the earth from loosing as much heat as it would otherwise. The earth doesn't radiate all of it's heat back to space, it is recaptured by the greenhouse gasses and backscattered again. The net result is that the earth doesn't cool off as much as it would if there were no greenhouse gasses.

now...
If you were to consider that there are other things up in the air that do not suffer the same constraints as CO2, H2O for example, then perhaps we can get somewhere. Remember that H2o has the unique ability to change it's form in the free atmosphere (external work ?) not to mention the fact that its FAR more prevalent.

Furthermore, water as a greenhouse gas is a negative feedback process. The more water in the atmosphere, the more IR it blocks, so the atmosphere gets colder and doesn't hold as much water vapor. The less water vapor, the less IR it blocks so the atmosphere becomes warmer. That keeps the atmosphere more stable from night to day, as it comes to an oscillating equilibrium. Water has the special quality of having a huge fast sink and source of it in the ocean. CO2 and methane have a much longer sink/source half-life so there is very little negative feedback stabilization.

 

[dogtowner]

Not exactly. The net effect is that the CO2 backradiation prevents the earth from loosing as much heat as it would otherwise.

How ?
It has nearly no capacity to retain nor can it direct it to a warmer thing.

 

[Lagboltz]

How ?
It has nearly no capacity to retain nor can it direct it to a warmer thing.

If CO2 doesn't retain any heat, it is in close thermal contact with O2 and N2 which can retain heat. CO2 scatters it's resonant wavelengths everywhere, and that everywhere also includes earth.

It is said that CO2 has a cooling effect on the earth by backscattering IR into space. You can also look at backscattering as having a warming effect on outer space.

Using the same physical mechanism, backscatter of CO2 in the troposphere has a warming effect on the earth mantle.

 

[dogtowner]

If CO2 doesn't retain any heat, it is in close thermal contact with O2 and N2 which can retain heat. CO2 scatters it's resonant wavelengths everywhere, and that everywhere also includes earth.

ONLY H2O has this capacity do to its ability to change form (external work).
Everywhere must, by the law, exclude earth.

It is said that CO2 has a cooling effect on the earth by backscattering IR into space. You can also look at backscattering as having a warming effect on outer space.

It has a cooling effect because is has next to zero ability to redirect energy at all so it just keeps sailing out. And it dissipates once there since there is nothing at all to do anything with that energy. It winds up somewhere though so its not lost.

Using the same physical mechanism, backscatter of CO2 in the troposphere has a warming effect on the earth mantle.

I guess we may have to agree to disagree as what you suggest simply can't happen without rewriting the laws of thermodynamics.

 

[Lagboltz]

ONLY H2O has this capacity do to its ability to change form (external work).
Everywhere must, by the law, exclude earth.

Sure, that too.

It has a cooling effect because is has next to zero ability to redirect energy at all so it just keeps sailing out. And it dissipates once there since there is nothing at all to do anything with that energy. It winds up somewhere though so its not lost.

I was emphasizing a different perspective to compare it with what it does to the mantle -- backscattering has a "warming" effect to whatever it is backscattering to.

I guess we may have to agree to disagree as what you suggest simply can't happen without rewriting the laws of thermodynamics.

Look, I'm not saying that CO2 warms the earth, I'm just saying that the earth doesn't get as cold as it would without it.

If there were no water or other greenhouse gasses, the earth would be much colder than it is. Look at the dry Sahara, it has a day-night temperature range of 63 deg F, while a humid tropical rain forest has a day-night span of 4 to 10 deg F.

 

[dogtowner]

Sure, that too.

I was emphasizing a different perspective to compare it with what it does to the mantle -- backscattering has a "warming" effect to whatever it is backscattering to.

Look, I'm not saying that CO2 warms the earth, I'm just saying that the earth doesn't get as cold as it would without it.

If there were no water or other greenhouse gasses, the earth would be much colder than it is. Look at the dry Sahara, it has a day-night temperature range of 63 deg F, while a humid tropical rain forest has a day-night span of 4 to 10 deg F.

No back scattering from anything but the water as those things haven't the ability. I'm glad you note the dramatic effect of water.

Now if you are ready to accept that CO2 makes no difference as it related to "climate change" I would entertain some discussion as to whether or not levels of it are beneficial or not beneficial in other terms. Hard to see it as a pollutant since plants eat it and animals exhale it but perhaps there are other aspects.

 

[Lagboltz]

No back scattering from anything but the water as those things haven't the ability. I'm glad you note the dramatic effect of water.

Now if you are ready to accept that CO2 makes no difference as it related to "climate change" I would entertain some discussion as to whether or not levels of it are beneficial or not beneficial in other terms. Hard to see it as a pollutant since plants eat it and animals exhale it but perhaps there are other aspects.

I'm not sure I understand what you mean "no backscattering from anything but the water", and that CO2 makes no difference. Both CO2 and H2O have resonant absorption/reemission bands which I would think have the same IR backscattering effect on earth, but of course H2O is much more complicated in that it is a stronger effect and can liquify, etc.

 

[dogtowner]

I'm not sure I understand what you mean "no backscattering from anything but the water", and that CO2 makes no difference. Both CO2 and H2O have resonant absorption/reemission bands which I would think have the same IR backscattering effect on earth, but of course H2O is much more complicated in that it is a stronger effect and can liquify, etc.

have to absorb to re-emit and CO2 or the other "greenhouse gasses" that are not water have near zero ability to absorb. no absorb, no re-emit.

now you could make a case that man has had the effect of placing more water in the air and if it were possible to measure the global mean temperature accurately might have a warming effect (more to absorb and re-emit). or you could look for other reasons for any warming that might be happening.

but the topic of this thread was just that global mean temperature thing. there has been no small amount of hanky panky associated with this in an effort to make this CO2 idea work and I think its important for people to know that "science" has not been playing straight.

trust but verify is a pretty good way to digest these things.

 

[Lagboltz]

have to absorb to re-emit and CO2 or the other "greenhouse gasses" that are not water have near zero ability to absorb. no absorb, no re-emit.

I will have to look into that further. I have not looked for any quantitative numbers on CO2 scattering properties. I believe the mean path of the CO2 emission and absorption is around 30 feet, but I will have to check that. The actual absorption profile would come from "Beers Law". If you have a reliable source let me know, but I will have to "trust but verify".

now you could make a case that man has had the effect of placing more water in the air and if it were possible to measure the global mean temperature accurately might have a warming effect (more to absorb and re-emit). or you could look for other reasons for any warming that might be happening.

Right, there are other things happening.

but the topic of this thread was just that global mean temperature thing. there has been no small amount of hanky panky associated with this in an effort to make this CO2 idea work and I think its important for people to know that "science" has not been playing straight.

Yes, global mean temperature was the original topic, and I have more to say on it (That was the basis of the pool example where PR insisted on a bucket, method and avoided the meaning of the example, so I went to a CAT scan example, where he had no comment.)

People were pushing to change the mean temperature topic to the physics of warming. I obliged, and the topic digressed over a misunderstanding of the thermodynamics of post 56, which I tried to clarify with light bulbs and hotplate examples. I will clarify that using no examples in the next post so we can move on.

trust but verify is a pretty good way to digest these things.

I am willing to listen to anti-warmers, (or whatever you call yourselves) but their physics has to be correct. That was one thing that Pale was unable to do, so it took us in tedious directions, and never stopped.