Greenhouse Gases Identified 150 Years Ago

[kenfeldman]

New Scientist has a nice article on John Tyndall, the scientist who discovered the greenhouse gases in the atmosphere 150 years ago.

www.newscientist.com/article/mg20227081.500-the-man-who-discovered-greenhouse-gases.html

The year 1859 was one of those nose-to-the-grindstone years. Tyndall was stuck in London juggling his science, a strenuous round of lectures and writing his first book - on the subject of glaciers. He was familiar with the notion of the "greenhouse effect", first mooted in the 1770s and developed in the 1820s by Frenchman Joseph Fourier, one-time secret policeman, governor of Egypt and physicist. Fourier pondered the question of why the Earth was warmer than physics suggested it should be, and concluded that while the light from the sun penetrated the atmosphere easily and heated the Earth, the heat radiated by the Earth couldn't pass back through the atmosphere quite so easily. He suspected that the atmosphere blocked the passage of radiant heat - infrared radiation - from the Earth, preventing its escape into space. A few years later, another Frenchman, Claude Pouillet, speculated that certain gases in the atmosphere were responsible for trapping radiant heat.

"This view required experimental verification," declared Tyndall. Physicists had recently studied the heat-absorbing properties of liquids and solids, but the general view was that gases were transparent to heat or absorbed imperceptible amounts. The immediate challenge was to devise a means of detecting the undetectable.

Tyndall began to work on a piece of apparatus sensitive enough to register the heat absorbed by a slim tube filled with gas. On 9 May, he tested his apparatus and tried it out on some simple gases. "As yet no effect observed," he wrote in his journal. By 18 May, he had cracked it: "Experimented all day; the subject is completely in my hands."

Now he found that air definitely intercepted some heat. He tried more gases, "and with the most remarkable results". The main gases in the atmosphere, oxygen and nitrogen, proved virtually transparent to heat, while more complex, compound molecules absorbed heat much more powerfully. Coal gas - a mix of carbon monoxide, methane and other hydrocarbons - turned out to be as much a barrier to radiant heat as a piece of wood. Further experiments showed that carbon dioxide and water vapour were particularly good at blocking heat radiation, and that it was these gases that were responsible for absorbing most of the heat trapped by the atmosphere.

On 10 June, Tyndall demonstrated his experiments before a packed meeting at the Royal Institution, with Albert the prince consort in the chair. "To the eye, the gas within the tube might be as invisible as the air itself, while to the radiant heat it behaved like a cloud which it was almost impossible to penetrate. Thus, the bold and beautiful speculation has been made an experimental fact. The radiant heat of the sun does certainly pass through the atmosphere to the Earth with greater facility than the radiant heat of the Earth can escape into space."

[sigurdur]

The radiant heat of the sun does certainly pass through the atmosphere to the Earth with greater facility than the radiant heat of the Earth can escape into space"

Which is a very good thing as I enjoy living. IF the opposite were true, we wouldn't be having this conversation.

[Ratty]

I suppose there may be someone who frequents this forum who doesn't know about the greenhouse effect.

I'm just curious about the reason behind this thread.

[kiwistonewall]

There is no greenhouse effect(as caused by greenhouse gases). Its a Myth like Phlogiston. (Nobody who opposes a current paradigm is ever popular) ;D

The atmosphere as a whole retards heat escape to space. Fact.
The thicker the planetary atmosphere, the greater the effect. That is the "greenhouse" effect - nothing to do with "greenhouse" gases.

Without wanting to be a troll, or to make Steve et al froth at the mouth, I will repeat the science:

1. Every absorber of IR is an equal and opposite emitter of IR. Thus, adding so called greenhouse gases is a zero sum game.

2. The atmosphere heats by direct solar warming+ convection and latent heat of water (evapouration driven by the sun).

3. There is no link with temperature and greenhouse gases (historically or today).

4. The theory cannot be shown mathematically, only by conjecture and waving of hands! it has no physical or experimental evidence to support it.

5. Mars with much more CO2 than Earth, but a thin atmosphere, is COLD. Venus with a thick atmosphere (mostly CO2, but that is irrelevant) is HOT.


There is no "greenhouse" effect as thought by the ancients (of 150 yrs ago, or still around today!) ;D

Arguing with a believer is pointless. Disagreeing with an accepted paradigm by anyone needing funding is dangerous. Those great scientists working in other fields are hardly going to rock the CO2 boat.

But no amount of yelling, pontificating, can overturn the fundamental laws of physics and thermodynamics.

The classical "greenhouse gas" greenhouse effect is Rubbish.

Have fun frothing & listing all the scientists who disagree - Science isn't democracy, but experimentally verifiable facts, and there are non that support the IR absorbing gases causing the greenhouse effect. We'd have the same temperature on Earth without CO2 (except that we need it for life!!! ;D)

Enjoy blasting me and venting your fury. I'll just watch & smile & think how stupid it is, that nearly the entire scientific establishment is wrong!

[nautonnier]

I find that the blind spot is the implication that the ONLY way for heat to reach the tropopause is by radiation. This is patently untrue as most is carried up to the tropopause by convection. Almost all that heat is carried by water vapor that evaporated at the surface (cooling it - i.e. taking heat from it) ) and then is carried upward by convection releasing the heat by state change back to liquid and/or ice crystals at higher altitude. The higher the ambient heat the more water-vapor transport of heat in this way.

Yet every time water vapor is mentioned instead of looking at convection and state changes as the heat transport the AGW proponents display graphs of IR absorption comparisons with CO₂. This is because CO₂ can ONLY scatter radiation (absorb and re-emit randomly) and has no state change. This AGW one-club-golfer approach to the atmosphere leads to all sorts of misassumptions "based on 'physics'" which are then put into models which unsurprisingly prove the misassumptions.

[steve]

May 20, 2009 9:52:10 GMT nautonnier said:

I find that the blind spot is the implication that the ONLY way for heat to reach the tropopause is by radiation.

You're hedging your bets as you cannot really have an implied blind spot. As it happens, there isn't such a blind spot in the science.

[nautonnier]

May 20, 2009 9:58:32 GMT steve said:

May 20, 2009 9:52:10 GMT nautonnier said:

I find that the blind spot is the implication that the ONLY way for heat to reach the tropopause is by radiation.

You're hedging your bets as you cannot really have an implied blind spot. As it happens, there isn't such a blind spot in the science.

I am pleased to hear that - as apart from mickey mouse diagrams based on unproven assumptions - the only 'calculation' you and others show on here are based on radiative formulae. This would be fine if these only used the radiation from the tropopause outward but its always based on radiation 'from the surface' of the Earth in watts per square metre using expected absorption in the entire atmosphere.

[steve]

May 20, 2009 11:30:13 GMT nautonnier said:

May 20, 2009 9:58:32 GMT steve said:

You're hedging your bets as you cannot really have an implied blind spot. As it happens, there isn't such a blind spot in the science.

I am pleased to hear that - as apart from mickey mouse diagrams based on unproven assumptions - the only 'calculation' you and others show on here are based on radiative formulae. This would be fine if these only used the radiation from the tropopause outward but its always based on radiation 'from the surface' of the Earth in watts per square metre using expected absorption in the entire atmosphere.

Nautonnier,

The calculation of forcing is the based on the difference in outgoing longwave radiation at the top of the atmosphere, and accounts for radiation and absorption from all levels within the atmosphere and from the surface.

This is not the only calculation that I "and others" have shown, though I suppose you ought not base all your anti-AGW arguments on what is said in this forum alone.

[nautonnier]

May 20, 2009 13:47:04 GMT steve said:

May 20, 2009 11:30:13 GMT nautonnier said:

I am pleased to hear that - as apart from mickey mouse diagrams based on unproven assumptions - the only 'calculation' you and others show on here are based on radiative formulae. This would be fine if these only used the radiation from the tropopause outward but its always based on radiation 'from the surface' of the Earth in watts per square metre using expected absorption in the entire atmosphere.

Nautonnier,

The calculation of forcing is the based on the difference in outgoing longwave radiation at the top of the atmosphere, and accounts for radiation and absorption from all levels within the atmosphere and from the surface.

This is not the only calculation that I "and others" have shown, though I suppose you ought not base all your anti-AGW arguments on what is said in this forum alone.

Well I have yet to see a calculation of the amount of heat carried by evaporation of water at the surface and its convection from the surface to the upper layers of the troposphere. Also the effect on convection of changes of state and the various latent heats. As your response shows there is only accounting for radiation and absorption.

I would be more than happy if radiation was calculated as if from the top surface of the atmosphere (if that is identifiable) in watts per square metre of the surface of the atmosphere. But it is reduced (in all that I have read) to watts per square metre at the surface, then what appear to be simplistic arguments made about the amount of CO₂ in the atmosphere when most of the density of the atmosphere is below the tropopause and is largely bypassed by convection. The hydrologic cycle, clouds and their effects are admitted to be poorly modeled so just taking the top of the atmosphere would be a way out. Of course as the atmosphere appears to have shrunk by 3% this may complicate comparisons.

[steve]

May 20, 2009 15:15:54 GMT nautonnier said:

May 20, 2009 13:47:04 GMT steve said:

Nautonnier,

The calculation of forcing is the based on the difference in outgoing longwave radiation at the top of the atmosphere, and accounts for radiation and absorption from all levels within the atmosphere and from the surface.

This is not the only calculation that I "and others" have shown, though I suppose you ought not base all your anti-AGW arguments on what is said in this forum alone.

Well I have yet to see a calculation of the amount of heat carried by evaporation of water at the surface and its convection from the surface to the upper layers of the troposphere. Also the effect on convection of changes of state and the various latent heats. As your response shows there is only accounting for radiation and absorption.

I would be more than happy if radiation was calculated as if from the top surface of the atmosphere (if that is identifiable) in watts per square metre of the surface of the atmosphere. But it is reduced (in all that I have read) to watts per square metre at the surface, then what appear to be simplistic arguments made about the amount of CO₂ in the atmosphere when most of the density of the atmosphere is below the tropopause and is largely bypassed by convection. The hydrologic cycle, clouds and their effects are admitted to be poorly modeled so just taking the top of the atmosphere would be a way out. Of course as the atmosphere appears to have shrunk by 3% this may complicate comparisons.

The IPCC definition of forcing relates to top of atmosphere.

The hydrological cycle is reasonably well modelled (that's what the forecast models do). This is what helps define the temperature and humidity profile of the atmosphere.

The uncertainty is in the small changes to the cycle that occur as a response to warming and which affects the radiative balance by changing water vapour levels and clouds.

When it comes down to it though, the earth is roughly a closed system except for radiation in and radiation out. And the amounts of radiation in and radiation out at any one time are not affected by the amount of energy being shifted about the sysem through convection and the like at that same moment.

[socold]

The tropopause is surely chosen for radiative forcing precisely becuase that's the level at which convection becoms irrelevant. The stratosphere is stratified because of the lack of convection.

[socold]

May 20, 2009 15:15:54 GMT nautonnier said:

Well I have yet to see a calculation of the amount of heat carried by evaporation of water at the surface and its convection from the surface to the upper layers of the troposphere. Also the effect on convection of changes of state and the various latent heats. As your response shows there is only accounting for radiation and absorption.

Ah the "I haven't seen it therefore it doesn't exist" argument.

The models contain a 3D grid of the atmosphere. All energy into and out of each grid cell is calculated. Convection, radiation, you name it, it's calculated.

[hiddigeigei]

May 20, 2009 19:55:47 GMT socold said:

May 20, 2009 15:15:54 GMT nautonnier said:

The models contain a 3D grid of the atmosphere. All energy into and out of each grid cell is calculated. Convection, radiation, you name it, it's calculated.

Is the code available?

[tacoman25]

May 20, 2009 19:55:47 GMT socold said:

May 20, 2009 15:15:54 GMT nautonnier said:

Well I have yet to see a calculation of the amount of heat carried by evaporation of water at the surface and its convection from the surface to the upper layers of the troposphere. Also the effect on convection of changes of state and the various latent heats. As your response shows there is only accounting for radiation and absorption.

Ah the "I haven't seen it therefore it doesn't exist" argument.

The models contain a 3D grid of the atmosphere. All energy into and out of each grid cell is calculated. Convection, radiation, you name it, it's calculated.

Well then, the models MUST BE perfect and undoubtedly realistic!

Wish they would transfer these perfect calculations over to weather models, since they tend to lose accuracy quickly into the future...

[hiddigeigei]

May 20, 2009 19:55:47 GMT socold said:

May 20, 2009 15:15:54 GMT nautonnier said:

Well

The models contain a 3D grid of the atmosphere. All energy into and out of each grid cell is calculated. Convection, radiation, you name it, it's calculated.

The models contain a 3D grid of the atmosphere. All energy into and out of each grid cell is calculated. Convection, radiation, you name it, it's calculated.

Very interesting! How big are these cells. Are these cells equal-sided or do they vary shape. Does each cell have only six neighbors? Does each cell changes state depending on its state and the state of neighboring cells based on a bunch of linear differential equations calculated by multiprocessors in discrete time steps... (Euler integration) or are the equations solved mathematically for varying lengths of times? Are there probability functions for each cell; say to determine whether a dust particle causes condensation of water vapor or perhaps cosmic rays form raindrop nuclei? In the latter case, would the probability function change based on solar flux or even sunspot numbers predicted by Dr. Hathaway?

Inquiring minds would like to know.