(05-29-2013 12:35 PM)DrTorch Wrote:  

(05-29-2013 11:24 AM)mlb Wrote:  Now I'm no expert, but from reading that article doesn't it basically say it acts like a insulator? Keeps heat in and out? That is how I took it... kept it from getting through to the surface of the earth. It would go to reason that then the heat that does make it to the surface gets trapped on the inside of those CO2 and NO particles in the same way.

Kind of. It absorbed the energy, then emitted it back into space. An insulator tends to have low absorption, and very low thermal flow. For low absorption an insulator is often reflective, and by definition that doesn't emit well. So most standard insulators just don't take in the energy to start with.

The gases absorbed the sun's radiation, then emitted it (relatively) rapidly into the cool of open space.

But, it's not exactly the same for trapping heat from the surface. Two things are different. First, the radiation won't just radiate back to the surface b/c it's warm. Radiation will flow toward the cold. So, absorption of surface radiation by thermosphere gases will still lead to cooling of the earth, but it is slowed, and that's part of why extra greenhouse gases are potentially a problem.. So that's where it is similar as you say. But it's not the most important issue.

The real issue is the wavelength of the radiation. What came from the sun was largely in the IR region where the gases could absorb and emit, matching vibration of the atoms w/in the molecules. What gets through to the Earth may start as absorbed IR radiation, but when absorbed, the energy changes from vibrational to rotational and translational (which we perceive as heat/warmth). This energy can be emitted too, but it happens (much) less rapidly, so the energy is effectively stored w/in the gases.

This is why a greenhouse works, and your car gets hot on a sunny day, but it is just one piece of the complex system of the planet, and it's not "plain and simple" that slight changes in CO2 will have major effects on temp.

I have been reading these global warming threads but have refused to post, but I had to respond to this since it uses a lot of scientific terms that aren't quite correct.

What comes from the Sun is largely in the visible region, see below.



The y-axis is flux, so how much of something (in this case light) flows through per time unit. The difference between the two curves is absorption of solar radiation and the noticeable dips correspond to the vibrations that you talk about. Vibrational transitions are smack bang in the infrared. Most of this absorption is water, that's the big killer for infrared telescopes, if you look up at the sky, much of the infrared light coming from stars is effectively blocked off because of water. CO2 and methane as well as other molecules also absorb light in this region.

The greenhouse effect simply put is as follows. Light coming from the Sun is mainly in the visible (that's why we can see it) and comes down through the atmosphere, pretty much uninhibited. It hits the Earth and is absorbed. It is then re-emitted at a different wavelength. If this re-emission is in certain parts of the infrared (where those water, CO2 and methane absorption peaks occur) then when they get to the atmosphere, they encounter some gas and get absorbed then re-emitted once more. This re-emission can go anywhere, up or down. The important part is that what radiation was going to go back to space (if there wasn't a particular molecule in the way) now has a probability of being returned back to Earth, the Earth heats up and warming ensues.

The more CO2 (and certain other molecules) that you have in the atmosphere, the more likely it is that the reflected light will encounter a molecule, be absorbed and re-emitted back down to Earth. Are greenhouse gases the only things that lead to the temperature of the Earth changing? No. They do clearly though, have an effect.

Another important point to do with this NASA study is that there isn't much gas out in the upper atmosphere, that's not where the greenhouse effect occurs, it happens in the lower atmosphere where there is much more gas, orders of magnitude more. This is a very specific study about radiation from solar events being reflected in the upper atmosphere, it is nothing to do with global warming.

(05-29-2013 02:26 PM)dmacfour Wrote:  I have friends who say things like that too, but I'm not going to take their word for it. None of them actually study earth sciences.

I don't take the word of "scientists" whom are rewarded for finding things instead of debunking things either. In this case, we know for a fact data has been skewed and still don't fully know what is true and what is not.

I keep an open mind because I don't believe we understand the heating and cooling periods of the past fully, so some short term "warming" of this planet may mean absolutely nothing in the current situation just as those essentially didn't.

I really, more than anything, believe there is a lot of climate "fear-mongering" going on and not enough true researching into debunking the theories. Correllation does not equal causation, and until we have definitive proof I'll keep my mind open.

(05-29-2013 03:08 PM)ODUgradstudent Wrote:  

(05-29-2013 12:35 PM)DrTorch Wrote:  

(05-29-2013 11:24 AM)mlb Wrote:  Now I'm no expert, but from reading that article doesn't it basically say it acts like a insulator? Keeps heat in and out? That is how I took it... kept it from getting through to the surface of the earth. It would go to reason that then the heat that does make it to the surface gets trapped on the inside of those CO2 and NO particles in the same way.

Kind of. It absorbed the energy, then emitted it back into space. An insulator tends to have low absorption, and very low thermal flow. For low absorption an insulator is often reflective, and by definition that doesn't emit well. So most standard insulators just don't take in the energy to start with.

The gases absorbed the sun's radiation, then emitted it (relatively) rapidly into the cool of open space.

But, it's not exactly the same for trapping heat from the surface. Two things are different. First, the radiation won't just radiate back to the surface b/c it's warm. Radiation will flow toward the cold. So, absorption of surface radiation by thermosphere gases will still lead to cooling of the earth, but it is slowed, and that's part of why extra greenhouse gases are potentially a problem.. So that's where it is similar as you say. But it's not the most important issue.

The real issue is the wavelength of the radiation. What came from the sun was largely in the IR region where the gases could absorb and emit, matching vibration of the atoms w/in the molecules. What gets through to the Earth may start as absorbed IR radiation, but when absorbed, the energy changes from vibrational to rotational and translational (which we perceive as heat/warmth). This energy can be emitted too, but it happens (much) less rapidly, so the energy is effectively stored w/in the gases.

This is why a greenhouse works, and your car gets hot on a sunny day, but it is just one piece of the complex system of the planet, and it's not "plain and simple" that slight changes in CO2 will have major effects on temp.

I have been reading these global warming threads but have refused to post, but I had to respond to this since it uses a lot of scientific terms that aren't quite correct.

What comes from the Sun is largely in the visible region, see below.


The y-axis is flux, so how much of something (in this case light) flows through per time unit. The difference between the two curves is absorption of solar radiation and the noticeable dips correspond to the vibrations that you talk about. Vibrational transitions are smack bang in the infrared. Most of this absorption is water, that's the big killer for infrared telescopes, if you look up at the sky, much of the infrared light coming from stars is effectively blocked off because of water. CO2 and methane as well as other molecules also absorb light in this region.

The greenhouse effect simply put is as follows. Light coming from the Sun is mainly in the visible (that's why we can see it) and comes down through the atmosphere, pretty much uninhibited. It hits the Earth and is absorbed. It is then re-emitted at a different wavelength. If this re-emission is in certain parts of the infrared (where those water, CO2 and methane absorption peaks occur) then when they get to the atmosphere, they encounter some gas and get absorbed then re-emitted once more. This re-emission can go anywhere, up or down. The important part is that what radiation was going to go back to space (if there wasn't a particular molecule in the way) now has a probability of being returned back to Earth, the Earth heats up and warming ensues.

That's some of it, but not all of it. Initially temp would rise, but there will be an equillibrium established of radiation going back and forth w/in the atmosphere at IR wavelengths. But there would always be a path for IR to escape radiating upward. In the end it would balance out, and you'd find modest change in temps, mostly delayed cooling in evenings. This is a pretty typical kinetics expression.

The real impact is the equipartition theorem comes into play, via inter- and intra-molecular vibrational relaxation, where the vibrational energy becomes rotational and translational. These modes can emit radiation too, but they will be at much lower frequencies (microwave or radio-wave) than IR radiation. Moreover, the rate of emission is related to the frequency of emission, so it's a much slower release of the energy. (That's why the Stefan-Boltzmann expression is T^4).

Quote:The more CO2 (and certain other molecules) that you have in the atmosphere, the more likely it is that the reflected light will encounter a molecule, be absorbed and re-emitted back down to Earth. Are greenhouse gases the only things that lead to the temperature of the Earth changing? No. They do clearly though, have an effect.

Again, that is some of it, but much of it is that the energy is transitioned to translation and rotation as heat in the atmosphere, not that it's just radiated back to the ground surface.

Quote:Another important point to do with this NASA study is that there isn't much gas out in the upper atmosphere, that's not where the greenhouse effect occurs, it happens in the lower atmosphere where there is much more gas, orders of magnitude more. This is a very specific study about radiation from solar events being reflected in the upper atmosphere, it is nothing to do with global warming.

Agreed. The transfer of energy between these layers is a complicated process, and part of why the models are so involved.

(05-29-2013 03:58 PM)mlb Wrote:  

(05-29-2013 02:26 PM)dmacfour Wrote:  I have friends who say things like that too, but I'm not going to take their word for it. None of them actually study earth sciences.

I don't take the word of "scientists" whom are rewarded for finding things instead of debunking things either. In this case, we know for a fact data has been skewed and still don't fully know what is true and what is not.

I keep an open mind because I don't believe we understand the heating and cooling periods of the past fully, so some short term "warming" of this planet may mean absolutely nothing in the current situation just as those essentially didn't.

I really, more than anything, believe there is a lot of climate "fear-mongering" going on and not enough true researching into debunking the theories. Correllation does not equal causation, and until we have definitive proof I'll keep my mind open.

Since when?

(05-29-2013 04:04 PM)DrTorch Wrote:  

(05-29-2013 03:08 PM)ODUgradstudent Wrote:  

(05-29-2013 12:35 PM)DrTorch Wrote:  

(05-29-2013 11:24 AM)mlb Wrote:  Now I'm no expert, but from reading that article doesn't it basically say it acts like a insulator? Keeps heat in and out? That is how I took it... kept it from getting through to the surface of the earth. It would go to reason that then the heat that does make it to the surface gets trapped on the inside of those CO2 and NO particles in the same way.

Kind of. It absorbed the energy, then emitted it back into space. An insulator tends to have low absorption, and very low thermal flow. For low absorption an insulator is often reflective, and by definition that doesn't emit well. So most standard insulators just don't take in the energy to start with.

The gases absorbed the sun's radiation, then emitted it (relatively) rapidly into the cool of open space.

But, it's not exactly the same for trapping heat from the surface. Two things are different. First, the radiation won't just radiate back to the surface b/c it's warm. Radiation will flow toward the cold. So, absorption of surface radiation by thermosphere gases will still lead to cooling of the earth, but it is slowed, and that's part of why extra greenhouse gases are potentially a problem.. So that's where it is similar as you say. But it's not the most important issue.

The real issue is the wavelength of the radiation. What came from the sun was largely in the IR region where the gases could absorb and emit, matching vibration of the atoms w/in the molecules. What gets through to the Earth may start as absorbed IR radiation, but when absorbed, the energy changes from vibrational to rotational and translational (which we perceive as heat/warmth). This energy can be emitted too, but it happens (much) less rapidly, so the energy is effectively stored w/in the gases.

This is why a greenhouse works, and your car gets hot on a sunny day, but it is just one piece of the complex system of the planet, and it's not "plain and simple" that slight changes in CO2 will have major effects on temp.

I have been reading these global warming threads but have refused to post, but I had to respond to this since it uses a lot of scientific terms that aren't quite correct.

What comes from the Sun is largely in the visible region, see below.


The y-axis is flux, so how much of something (in this case light) flows through per time unit. The difference between the two curves is absorption of solar radiation and the noticeable dips correspond to the vibrations that you talk about. Vibrational transitions are smack bang in the infrared. Most of this absorption is water, that's the big killer for infrared telescopes, if you look up at the sky, much of the infrared light coming from stars is effectively blocked off because of water. CO2 and methane as well as other molecules also absorb light in this region.

The greenhouse effect simply put is as follows. Light coming from the Sun is mainly in the visible (that's why we can see it) and comes down through the atmosphere, pretty much uninhibited. It hits the Earth and is absorbed. It is then re-emitted at a different wavelength. If this re-emission is in certain parts of the infrared (where those water, CO2 and methane absorption peaks occur) then when they get to the atmosphere, they encounter some gas and get absorbed then re-emitted once more. This re-emission can go anywhere, up or down. The important part is that what radiation was going to go back to space (if there wasn't a particular molecule in the way) now has a probability of being returned back to Earth, the Earth heats up and warming ensues.

Quote:That's some of it, but not all of it. Initially temp would rise, but there will be an equillibrium established of radiation going back and forth w/in the atmosphere at IR wavelengths. But there would always be a path for IR to escape radiating upward. In the end it would balance out, and you'd find modest change in temps, mostly delayed cooling in evenings. This is a pretty typical kinetics expression.

That's the point, if you perturb the system by adding more CO2 then you don't stay at equilibrium. It's not really kinetics either, this is thermodynamics if I understand what you're trying to say.

Quote:The real impact is the equipartition theorem comes into play, via inter- and intra-molecular vibrational relaxation, where the vibrational energy becomes rotational and translational. These modes can emit radiation too, but they will be at much lower frequencies (microwave or radio-wave) than IR radiation. Moreover, the rate of emission is related to the frequency of emission, so it's a much slower release of the energy. (That's why the Stefan-Boltzmann expression is T^4).

Translational energy isn't a spectroscopic mode, it's essentially what temperature is, or an analog for temperature. Equipartition just shows that energy is moved around, you're saying that when molecules absorb at infrared wavelengths, the energy is shared and some of it goes to translational energy, i.e. heat. So CO2 absorbing IR light makes the atmosphere warmer.

Quote:The more CO2 (and certain other molecules) that you have in the atmosphere, the more likely it is that the reflected light will encounter a molecule, be absorbed and re-emitted back down to Earth. Are greenhouse gases the only things that lead to the temperature of the Earth changing? No. They do clearly though, have an effect.

Quote:Again, that is some of it, but much of it is that the energy is transitioned to translation and rotation as heat in the atmosphere, not that it's just radiated back to the ground surface.

This is occurring mainly in the troposphere, that is to say the boundary layer, where we live.

Quote:Another important point to do with this NASA study is that there isn't much gas out in the upper atmosphere, that's not where the greenhouse effect occurs, it happens in the lower atmosphere where there is much more gas, orders of magnitude more. This is a very specific study about radiation from solar events being reflected in the upper atmosphere, it is nothing to do with global warming.

Quote:Agreed. The transfer of energy between these layers is a complicated process, and part of why the models are so involved.

Exactly, the mesosphere and thermosphere aren't well understood at all.

This is getting messy, quotes within quotes, it's like quoteception. I just wanted to point out that to those who don't have a background in science, these findings are nothing to do with AGW or lack thereof, which I think we both agree on.

(05-29-2013 02:26 PM)dmacfour Wrote:  

(05-29-2013 02:21 PM)mlb Wrote:  RobertN, I'll be honest with you and I'm friends with several "scientific types" whom all are non-believers about humans causing the warmup. They say the math just doesn't add up in terms of the amount of CO2 produced by man and the increase in temperature. They say it just isn't possible. They all believe there are other causes that we don't understand yet, but will in the future.

I have friends who say things like that too, but I'm not going to take their word for it. None of them actually study earth sciences.

Caught in another bold faced lie!!

I highly doubt you have any friends

(05-29-2013 02:21 PM)mlb Wrote:  RobertN, I'll be honest with you... I'm friends with several "scientific types" whom all are non-believers about humans causing the warmup. They say the math just doesn't add up in terms of the amount of CO2 produced by man and the increase in temperature. They say it just isn't possible. They all believe there are other causes that we don't understand yet, but will in the future.

I am sure your "scientific types" don't work in climatology(or even meteorology for that matter). I wouldn't be a bit surprised if they work in the fossil fuel industry.

(05-30-2013 01:18 AM)RobertN Wrote:  

(05-29-2013 02:21 PM)mlb Wrote:  RobertN, I'll be honest with you... I'm friends with several "scientific types" whom all are non-believers about humans causing the warmup. They say the math just doesn't add up in terms of the amount of CO2 produced by man and the increase in temperature. They say it just isn't possible. They all believe there are other causes that we don't understand yet, but will in the future.

I am sure your "scientific types" don't work in climatology(or even meteorology for that matter). I wouldn't be a bit surprised if they work in the fossil fuel industry.

I wouldn't be the least but surprised if you were dropped on your head as a child.....multiple times.

(05-30-2013 01:18 AM)RobertN Wrote:  I am sure your "scientific types" don't work in climatology(or even meteorology for that matter). I wouldn't be a bit surprised if they work in the fossil fuel industry.

Physicists and chemists, all with educational backgrounds that would qualify them to review "data" and at least put their own beliefs in play. None work for the fossil fuel industry, 1 of them in the nuclear industry however (he'd be inclined to say that coal and oil is bad I'd guess since it would possibly benefit him).

I'm certainly not saying that the earth isn't warming, I just think that the causes and conclusions are far from known. We can run computer simulations all day but computers only spit out information based on the way they are programmed. That is why none of the "simulations" have come close to truly predicting the changes in earth patterns for the past 2 decades. We just don't know enough about the weather patterns in this earth to predict warming, whether natural or human caused.

Hell, they can't predict the exact weather for an hour from now, let alone 2 days. Who thinks they can predict 50 or 100 years into the future?

(05-29-2013 06:18 PM)Razor Ramon Monarch Wrote:  

(05-29-2013 02:26 PM)dmacfour Wrote:  

(05-29-2013 02:21 PM)mlb Wrote:  RobertN, I'll be honest with you and I'm friends with several "scientific types" whom all are non-believers about humans causing the warmup. They say the math just doesn't add up in terms of the amount of CO2 produced by man and the increase in temperature. They say it just isn't possible. They all believe there are other causes that we don't understand yet, but will in the future.

I have friends who say things like that too, but I'm not going to take their word for it. None of them actually study earth sciences.

Caught in another bold faced lie!!

I highly doubt you have any friends

Oh look, the resident as.should appeared.

Cannot expect scientists to know all. Not yet. Maybe some day. Maybe not.