What explanation of the Greenhouse Effect do you use?

[IanC]

I am not at all clear what you mean, or how two bands would increase the layperson's understanding of the GHE. How about you re-work the text?

4. Effectively, infrared radiation emitted to space originates from an altitude with a temperature of, on average, –19°C, in balance with the net incoming solar radiation, whereas the Earth’s surface is kept at a much higher temperature of, on average, +14°C.

Remember, too, that IR radiation escaping through the Atmospheric Window does not contribute to the GHE, and thus doesn't belong into the definition

Increasing GHGs actually decreases IR radiation escape in the bands they interact with, by increasing the emission height. That really would lead to runaway warming if there was nothing to replace the output.

The freely escaping radiation at the surface does exactly that. Stop a watt of GHG IR and the system will store that energy untill the surface warms enough to push an extra watt of energy through the Atmospheric Window. Equilibrium is restored but the surface and atmosphere have warmed. This is not 'new' energy. It is energy that wasnt given to space.

 

[IanC]

I looked for a reasonably scientific explanation of the GHE on Google and was very disappointed. You would think it would be everywhere but it isnt.

I then specifically searched for the IPCC version. Imagine my surprise when 'denier' sites were the major places of discussion.

How weak is their case if they are effectively hiding it? For the record, I believe in the GHE in principle as a very important part of atmospheric radiative physics. I don't see how the addition of more CO2 can cause huge changes though.

What is your reference site for the GHE? Or do you just know it?

I'll post up a few links later if no one cares to post theirs.

Here's the rub.... This is where the Gaia worshipers go wrong every time. No field of science stands alone all by itself especially in our ecosystem. CO2 concentrations are affected by many different sources and sinks. Ask any oceanographer and he will tell you that the water temperature is directly related to how much CO2 can remain dissolved in the seawater at any given time.

Since the oceans cover 2/3 of the Earth's surface they are a far more significant source and far more significant sink of CO2 than any other single source or sink. 1/10 degree temperature increase in the average sea water temperature globally would release hundreds of billions of tons of CO2 into the atmosphere. What is causing the oceans to heat up? No one is really quite sure of that However astronomers who study the sun, and vulcanologists who study tectonic movements of the Earth together with its volcanic systems both on land and on the sea... each have contributions to make to that particular mystery.

AGW Climatologists are the only ones that shut the door on all the other branches of science insisting that only their input matters when it comes to the very complex analysis of the CO2 cycle in our ecosystem.

Jo

Sorry. The question is about the greenhouse effect. Written down and hopefully presented on an education website. Got one?

Man, Jo, that was a pretty cogent analysis of the broader picture of why many doubt the believers they would like see answered! Too bad you only got slammed by a guy who first ASKED for your opinion, claims to be a skeptic as well while slamming other skeptics and arguing for common GHT, but then, what can you really expect from an idiot who ridicules a person 40 times just for making a passing 2-word qualification of himself entering a debate then turns around and amazingly says he can't imagine for the life of himself why you don't like him? Then when you start to change your mind about him and compliment him and start liking the guy and offer the hand of friendship and well-intended advice thinking you're going to start having normal dialog with the guy, calls you an asshat, a bragger and condescending instead. Pretty bizarre.

Tis the norm for USMB.

IanC has real mental and emotional issues like a lot of people here, probably an Aspergers type high functioning Autistic and probably has never actually worked a day of his life in anything remotely related to climate, Earth Science or the like, which might explain his bizarre frenetic attitudes and behavior.

Meh .... I just mention some of the things that should be obvious to a child....
They choose not to see it.... Oh well.

Jo

I didnt say your comments were wrong (or right). I said they were off topic.

 

[IanC]

Read it again....it is just such an explanation.
True it only deals with one of the elements
CO2....

There were no links in your original comment.

If you think the ones that you have now added are up to snuff then we have different standards.

 

[Olde Europe]

Increasing GHGs actually decreases IR radiation escape in the bands they interact with, by increasing the emission height. That really would lead to runaway warming if there was nothing to replace the output.

That's most likely wrong. I'd say, with a warmer ground, a steeper energy gradient, more photons traveling, conduction and convection doing their part, the energy transfer rate adjusts back upward to the previous equilibrium - so as to match solar input. With, say (grabbing figures out of thin air), the emission level 500 meters higher, temperature half a degree Celsius lower, and the emission "surface" proportionally bigger, the same output to space might be achieved.

Of course, we're talking about a 1°C rise in surface temperature on average. I doubt the IR emission band is changed so much that a significantly higher portion escapes through the AW, and I have seen no one arguing that (which may not mean that much, admittedly).

Again, this appears to me to be a sideshow, perhaps your hobby horse. How does the detailed physics of heat transfer facilitate the layperson's understanding of the GHE?

 

[toobfreak]

Read it again....it is just such an explanation.
True it only deals with one of the elements
CO2....

There were no links in your original comment. If you think the ones that you have now added are up to snuff then we have different standards.

Did I blink? You've made 999 claims in this thread and I've YET to see you link any of it to any sort of credible, independent (not committed to proving GWT) source!

SNIFF SNIFF. P.U.

Something smells afoul on the farm again.

 

[justoffal]

Increasing GHGs actually decreases IR radiation escape in the bands they interact with, by increasing the emission height. That really would lead to runaway warming if there was nothing to replace the output.

That's most likely wrong. I'd say, with a warmer ground, a steeper energy gradient, more photons traveling, conduction and convection doing their part, the energy transfer rate adjusts back upward to the previous equilibrium - so as to match solar input. With, say (grabbing figures out of thin air), the emission level 500 meters higher, temperature half a degree Celsius lower, and the emission "surface" proportionally bigger, the same output to space might be achieved.

Of course, we're talking about a 1°C rise in surface temperature on average. I doubt the IR emission band is changed so much that a significantly higher portion escapes through the AW, and I have seen no one arguing that (which may not mean that much, admittedly).

Again, this appears to me to be a sideshow, perhaps your hobby horse. How does the detailed physics of heat transfer facilitate the layperson's understanding of the GHE?

Correct... The climate is actually more resilient than the AGW isolationsts think.

Jo

 

[justoffal]

Read it again....it is just such an explanation.
True it only deals with one of the elements
CO2....

There were no links in your original comment.

If you think the ones that you have now added are up to snuff then we have different standards.

There's not much snuff to sniff in that category. I mean you can find papers that use all of the differential math and complex Cartesian integrals just to say that the sky is blue if that makes you feel more official about it. Not sure why that's necessary. If I were to prove the earth Earth is flat with twenty pages of progressive linear equations all it would really do is look impressive.....it certainly wouldn't be true.

Jo

 

[IanC]

That's most likely wrong. I'd say, with a warmer ground, a steeper energy gradient, more photons traveling, conduction and convection doing their part, the energy transfer rate adjusts back upward to the previous equilibrium - so as to match solar input. With, say (grabbing figures out of thin air), the emission level 500 meters higher, temperature half a degree Celsius lower, and the emission "surface" proportionally bigger, the same output to space might be achieved.

Interesting. Do you feel like explaining more? Or would that be putting you on the spot?

How does the surface warm up? Where does the energy come from? Until the surface actually warms there is nothing extra there. Or is there?

The extra surface area 1/2 a kilometre up is a pretty small amount. The dry lapse rate is what...about 6.5C/kilometre? The radiation rate is kT^4. Im thinking the increase in area is insufficient to cancel out the loss of radiation.

What would be the predictions for my explanation? (I cant make them for yours yet). With an increase of CO2, the notch in escaping radiation at 15 microns should deepen ( and widen, but we haven't discussed that yet). The surface should warm, pushing more radiation through the AW.

Do you think there has been measurements over the same area, under the same conditions, but 15 or 30 years apart so that there was time for CO2 to increase and temps to move towards equilibrium?

Hahahahaha. Youre saying 'here comes the trap'.

Anyways, fill in some of the gaps for your explanation and we'll talk some more.

 

[Olde Europe]

The extra surface area 1/2 a kilometre up is a pretty small amount. The dry lapse rate is what...about 6.5C/kilometre? The radiation rate is kT^4. Im thinking the increase in area is insufficient to cancel out the loss of radiation.

You appear to have missed my "grabbing figures out of thin air". Is the adiabatic lapse rate still valid at the outer reaches of the atmosphere? Moreover, methinks you are thinking "big loss of radiation" when that loss is actually pretty small, in the order of 0.18% (something like 0.6 out of 340W/m²). Moreover, there are, due to our FF burning, also more CO₂ molecules at the outer "border" of the atmosphere emitting photons into space in an atmosphere so thin, collisions are far less likely than at surface level.

Again, this appears to me to be a sideshow, perhaps your hobby horse. How does the detailed physics of heat transfer facilitate the layperson's understanding of the GHE?


Oh, and Ian, since I've seen that ad nauseam from the denialingdong crowd: Yes, my understanding of physics - while above average - is limited. That fact is not an argument against climate science, or the GHE.

 

[jc456]

Careful, JC, you are throwing this entire thread for a loop. The OP ASKED US WHAT GREENHOUSE MODEL EFFECTS WE USE, expecting only the ones which support man-made climate warming. He never asked you for any theories which do not FULLY SUPPORT man as the cause of everything

So you deny the obvious presence of the Greenhouse Effect?

I have more than a few quibbles about what happens when you increase the level of existing GHGs.

But to deny the entire effect is absurd.

Without Ghgs all of the surface radiation would leave at the spped of light. Even if all the solar radiation reached the surface and was absorbed, then the system would radiate at 340w. A lot less than the nearly 400w now.

show me a greenhouse that has ice in it. Let's forget that variable right?

Bad show, JC. A greenhouse in a garden is a lot different from the Earth. The sunlight hits the Earth over a wide range of incidence from head on to barely above the horizon. The greenhouse effect is real, and it raises some parts of the Earth to hotter than hell and other parts still cold enough that they still have ice, but ALL places are warmer than they would be otherwise. History shows us what the Earth is like without the comfort of GHGs, just look back to the Snowball Earth or the Huronian Ice Age.

That’s where I separate! It’s not greenhouse like, and why my analogy

But it IS greenhouse like. I say that both as a scientist and a gardener. The panes of glass work to contain the heat from the warming effects of the Sun much as the GH gases do with the Earth. The only question here is the output from man sufficiently modifying the atmosphere to cause eventual long term and catastrophic changes in Earth's climate?

Man doesn’t exist on 2/3’s of the planet. The oceans rule as do the poles. Then there is the rain forests. The planet doesn’t need us, but we need it!

 

[toobfreak]

Man doesn’t exist on 2/3’s of the planet.

Worse than that, JC, man is like only 1/10,000th of the Earth's biomass! Man is irrelevant. There is more fungus on the planet by weight than there is people. Plants make up like 80% of the biomass and bacteria come in a distant second. Even at that, there used to be far more plants until man started cutting all the trees down.

Mankind is like disease, a parasite like athlete's foot on the Earth. Man is a consumer of everything, natural resources, minerals, even himself. He gives back only pollution and waste to the Earth. Perhaps global warming is nature's fever from its only animal not living in harmony with its environment aimed at doing away with us like a bad head cold.

 

[IanC]

The extra surface area 1/2 a kilometre up is a pretty small amount. The dry lapse rate is what...about 6.5C/kilometre? The radiation rate is kT^4. Im thinking the increase in area is insufficient to cancel out the loss of radiation.

You appear to have missed my "grabbing figures out of thin air". Is the adiabatic lapse rate still valid at the outer reaches of the atmosphere? Moreover, methinks you are thinking "big loss of radiation" when that loss is actually pretty small, in the order of 0.18% (something like 0.6 out of 340W/m²). Moreover, there are, due to our FF burning, also more CO₂ molecules at the outer "border" of the atmosphere emitting photons into space in an atmosphere so thin, collisions are far less likely than at surface level.

Again, this appears to me to be a sideshow, perhaps your hobby horse. How does the detailed physics of heat transfer facilitate the layperson's understanding of the GHE?


Oh, and Ian, since I've seen that ad nauseam from the denialingdong crowd: Yes, my understanding of physics - while above average - is limited. That fact is not an argument against climate science, or the GHE.

look...all I was doing was making an attempt to clarify your reasoning. it is easy to make declaritive statements but much harder to defend them when questioned.

I think you have a fuzzy concept in your head about how the GHE works but I doubt that it can hold up to the most simple of criticisms. ie.like the ratio of increase of surface area to the decrease of radiation.

again...sorry I didnt mean to put you on the spot. I thought you were interested in this stuff.

 

[basquebromance]

 

[IanC]

Moreover, there are, due to our FF burning, also more CO₂ molecules at the outer "border" of the atmosphere emitting photons into space in an atmosphere so thin, collisions are far less likely than at surface leve

This is exactly the type of declaritive statement I was talking about.

The emission height is defined by the amount of CO2 present (n molecules per cm^3). increasing the ppm CO2 will push theemmision height up into thinner air but the amount of CO2 wwill remain the same (per cm^3). in thinner,colder air there will be less energy available to produce radiation.

You thought more radiation would be produced.

 

[SSDD]

My problem is that as IanC said in his OP there is a dearth of information. I tried looking at the general level of the OP, but it's buried in references that are impossible to get unless you pay $10 to $30 for a reprint of one paper that may not be what you thought it was. The IPCC only lightly summarizes the theory behind GHG's in what I could find.


.

That would be because there is no actual observed, measured evidence which establishes a coherent relationship between the absorption of IR by a gas and warming in the atmosphere...and if you pay for a reprint, you will just get more models and be no closer to anything real than you are now. When you get down to the "dirty math" you will find that there is nothing there...smoke and mirrors...models and metaphors....shuck and jive...bob and weave..but nothing whatsoever that even looks like actual observed, measured evidence for a radiative greenhouse effect as described by climate science..

And by the way...the IPCC gets as close to a precise explanation of the GHG hypothesis as is possible..get any closer and you can see the curtain moving as a result of the mechanizations of the man behind the curtain...or if you prefer some different imagery...you won't be able to ignore the pimples and warts on the emperor's naked ass.

 

[IanC]

What's wrong with it, where are things inaptly put, where do we need clarification?

3) What is the coupling/relationship of IR radiation with temperature?
4) What has the given temperature of the earth to do with anything, it is left hanging like an irrelevant factoid.
5) How does an increased infrared opacity of the atmosphere lead to an effective radiation into space from a higher altitude at a lower temperature?

Sorry. I seemed to have missed a set of on topic and reasonable comments.

#5. I am not sure what you mean. The amount of radiation produced by GHGs has been reduced because there is less available energy to produce it . j=eaT^4.

#3. There is more than one way to interpret this statement. Which temperature? IR is poor at directly warming things but it is still pretty good at reducing the cooling rate. The measured amount of IR coming back to the surface is more than the amount of sunshine!

Anyways, the way I see it, is the Greenhouse Effect is driven by the proportion of surface radiation that directly escapes vs the surface radiation that is captured and stored in the atmosphere.

The amount of radiation coming in from the sun must equal the amount leaving the earth, otherwise warming/cooling will occur.

Outgoing terrestrial radiation comes from 1. direct escape from the surface and 2. emission from the atmosphere by GHGs.

Add more CO2 and the atmosphere emits less radiation. The energy not escaping to space accumulates and is stored in the atmosphere/ surface. This will be expressed as an increase of temperature and the surface will produce more radiation, of which some fraction will escape directly and restore equilibrium.

This is a basic form of thermodynamics but there are added complexities that should be stated. Namely the emissivity of individual bands and the presence of a temperature gradient that affects production of radiation.

The IPCC references one average emission height and links it to the lapse rate. I think the surface escaping bands with an emissivity of zero should not be lumped together with atmosphere escaping bands with an emissivity of unity. How dissimilar do things have to be to avoid taking their average?

 

[mamooth]

Ignoring the badly behaved blowhard troll, I'll try to talk about the actual topic. Kudos to Ian for his saintly behavior here.

The best site I've seen for discussing atmospheric physics is The Science of Doom. It kind of lays things out like a textbook. Logical structure and it goes into a great deal of depth in each chapter.

Roadmap