Global Warming - Doomsday Called Off

[bigfish]

You tit.

Projection!

That's how heat moves from the ground to the air and how it circulates around the globe. In that case conduction and convection are very significant factors. However neither conduction nor convection have any relevance to how the earth (including atomosphere) shed energy.

They only get the heat into the air, they cannot, cannot, shed heat into a vacume. Hence why i laugh at your "heatsink of space" crap.

Bob: Planet Earth and its atmospheric envelope rotates in space. The convective process is driven by displacement of warm air at the surface by cool air from above, as shown in the Hadley convection cell diagram. Heat is transferred by this process to the upper layers of the atmosphere where it inevitably comes into contact with the heat sink of space and dissipates, thereby cooling the air. This is basic physics, Bob. You really ought to know better.

 

[dash_two]

'Dissipates' is a vague term, bigfish. Please be more specific.

Also, if there were no convective processes, would the Earth be warmer or cooler?

 

[WouldBe]

Heat is transferred by this process to the upper layers of the atmosphere where it inevitably comes into contact with the heat sink of space and dissipates, thereby cooling the air. This is basic physics, Bob. You really ought to know better.

Conduction and convection require a physical connection with something else. As space is a vacuum there is no physical contact so convection and conduction cannot work.

All the heat from the sun reaches us by radiation alone as this is the only way to transfer heat through the vacuum of space.

 

[bigfish]

So, bigfish, if there were no processes of convection or conduction, would the Earth be warmer or cooler?

There can be no convection without an atmosphere. With no atmosphere the surface of the planet would be minus 18 degrees Centigrade.

http://www.cato.org/pubs/regulation/regv15n2/reg15n2g.html

 

[WouldBe]

There can be no convection without an atmosphere. With no atmosphere the surface of the planet would be minus 18 degrees Centigrade.

http://www.cato.org/pubs/regulation/regv15n2/reg15n2g.html

So you now agree that you can't convect heat into space as there is no atmosphere in space.

 

[bigfish]

I wonder what Dr Owen Thompson thinks of bigfish's argument.

Why don't you drop him a line and find out?

 

[dash_two]

So does convection serve to warm or cool the Earth? Straight question, straight answer please.

 

[Fruitloop]

The earth does lose atmospere into space though, although not at a rate that would be influential for the purposes of this discussion.

 

[dash_two]

If you can address the issue of heat 'dissipating' that'd be nice too, thanks.

 

[bigfish]

Conduction and convection require a physical connection with something else. As space is a vacuum there is no physical contact so convection and conduction cannot work.

All the heat from the sun reaches us by radiation alone as this is the only way to transfer heat through the vacuum of space.

The simple picture of the greenhouse mechanism is seriously oversimplified. Many of us were taught in elementary school that heat is transported by radiation, convection, and conduction. The above representation only refers to radiative transfer. As it turns out, if there were only radiative heat transfer, the greenhouse effect would warm the Earth to about seventy-seven degrees centigrade rather than to fifteen degrees centigrade. In fact, the greenhouse effect is only about 25 percent of what it would be in a pure radiative situation. The reason for this is the presence of convection (heat transport by air motions), which bypasses much of the radiative absorption.


What is really going on is schematically illustrated in Figure 1. The surface of the Earth is cooled in large measure by air currents (in various forms including deep clouds) that carry heat upward and poleward. One consequence of this picture is that it is the greenhouse gases well above the Earth's surface that are of primary importance in determining the temperature of the Earth. That is especially important for water vapor, whose density decreases by about a factor of 1,000 between the surface and ten kilometers above the surface. Another consequence is that one cannot even calculate the temperature of the Earth without models that accurately reproduce the motions of the atmosphere. Indeed, present models have large errors here--on the order of 50 percent. Not surprisingly, those models are unable to calculate correctly either the present average temperature of the Earth or the temperature ranges from the equator to the poles. Rather, the models are adjusted or "tuned" to get those quantities approximately right.

http://www.cato.org/pubs/regulation/regv15n2/reg15n2g.html


WouldBe: I'll stick with Lindzen's description if that's alright with you

 

[WouldBe]

The earth does lose atmospere into space though, although not at a rate that would be influential for the purposes of this discussion.

It can only do it by radiation though or as someone else pointed out earlier if hot air molecules can reach escape velocity.

 

[kyser_soze]

I shouldn't worry about it - if there were 10,000 scientists saying that there was no such thing as global warming, BigFish would be there with the contrarian position cos his mission is not to necessarily be right, just to fight consensus views.

Witness the thread on 'Gas model of sun collapses', written in a breathless style that implies there was some kind of conspiracy to prevent the truth about Sol being known...

 

[Crispy]

Convection happens inside a thermos flask, but it's still just radiation that lets heat across the vacuum. And radiation that doesn't get absorbed by air (as everything but the very very top layer must pass through) doesn't need to come from the top, it can radiate from the bottom.

Besides, the stmosphere is not as simple as that,from the surface, it's warm, then it gets cold, then hot again, then cold again and then it's vacuum.

 

[bigfish]

If you can address the issue of heat 'dissipating' that'd be nice too, thanks.

Well, if you can formulate a coherent question, I will gladly oblige.

 

[dash_two]

"'Dissipates' is a vague term, bigfish. Please be more specific."

Coherent enough, I'd say.

And, yet again: if there were no convective processes, would the Earth be warmer or cooler?

 

[Fruitloop]

It can only do it by radiation though or as someone else pointed out earlier if hot air molecules can reach escape velocity.

Indeedy. I should read threads more carefully.

 

[WouldBe]

There can be no convection without an atmosphere. With no atmosphere the surface of the planet would be minus 18 degrees Centigrade.

http://www.cato.org/pubs/regulation/regv15n2/reg15n2g.html

As it turns out, if there were only radiative heat transfer, the greenhouse effect would warm the Earth to about seventy-seven degrees centigrade rather than to fifteen degrees centigrade.

So with no atmosphere the earths temp would be -18C in the first quote yet with radiative only transfer (i.e. with no atmosphere) the temp would be +77C in the second quote.

It can't be both so which is it? or does your 'expert' not know what he's talking about.

 

[dash_two]

Uh oh, we're in for an extra big diagram this time.

 

[bigfish]

As it turns out, if there were only radiative heat transfer, the greenhouse effect would warm the Earth to about seventy-seven degrees centigrade rather than to fifteen degrees centigrade.

So with no atmosphere the earths temp would be -18C in the first quote yet with radiative only transfer (i.e. with no atmosphere) the temp would be +77C in the second quote.

You are misrepresenting Lindzen's argument. What Lindzen said, was: if there were only radiative heat transfer (i.e. if there was no heat transfer by conduction or convection) then the Earth would warm to about +77C. That is not the same thing as saying: if there was "no atmosphere". If there was no atmosphere, then according to the Second Law of Thermodynamics, the temperature of the Earth would fall until it reached a new equilibrium with the space which surrounds it.

WouldBe: I have a question for you. If the energy output of our Sun were to fall by, say, 5%, how much additional CO2 would need to released into the atmosphere to prevent the temperature of the Earth from falling by a corresponding margin?

 

[Bob_the_lost]

... layers of the atmosphere where it inevitably comes into contact with the heat sink of space and dissipates, thereby cooling the air. This is basic physics, Bob. You really ought to know better.

You're taking the piss aren't you? You can't come into contact with nothing!

then according to the Second Law of Thermodynamics, the temperature of the Earth would fall until it reached a new equilibrium with the space which surrounds it.

I hate to break it to you, but even Einstien gave up on the Ether, space is empty, it can't have a temperature.

As you said, this is basic physics, why are you making such a hash of it?

 

[bigfish]

Bob; I have a question for you. If the energy output of our Sun were to fall by, say, 5%, how much additional CO2 would need to released into the atmosphere to maintain the original temperature?

Conversely, If the energy output of our Sun were to rise by, say, 5%, how much CO2 would need to extracted from the atmosphere to maintain the original temperature?

 

[Knotted]

To be fair to bigfish and Lindtzen, I believe that convection currents are significant in climate models and its conceivable that their effects are underestimated. However they do not operate in the way bigfish seems to think, I afraid bf's thesis is far too contrarian for even the contrarians.

The fact that the BBC do not give a perfectly detailed account of climate models, does not mean they are lying. Just simplifying for the sake of communicating.

 

[WouldBe]

You are misrepresenting Lindzen's argument. What Lindzen said, was: if there were only radiative heat transfer (i.e. if there was no heat transfer by conduction or convection) then the Earth would warm to about +77C. That is not the same thing as saying: if there was "no atmosphere".

Another consequence is that one cannot even calculate the temperature of the Earth without models that accurately reproduce the motions of the atmosphere. Indeed, present models have large errors here--on the order of 50 percent.

So if atmospheric models are nowhere near accurate then Lindzen's statement of a 77C rise in temp due to radiation alone are at best a guess.

WouldBe: I have a question for you. If the energy output of our Sun were to fall by, say, 5%, how much additional CO2 would need to released into the atmosphere to prevent the temperature of the Earth from falling by a corresponding margin?

I have no idea as I'm not a weather scientist. I can however see glaring holes in arguements.

 

[Bob_the_lost]

Bob; I have a question for you.

How the flying fuck would i know? Stop fucking about already.

I do know that there is no way for heat to leave the earth (including atomosphere) other than by radiation. How the fuck does air conduct heat to nothing? How does nothing carry heat by convection? That's what you've been blathering on about with your "heatsink of space" bullshit.

 

[dash_two]

Bigfish, my old matey, two simple, straightforward questions for you.

1. How does heat 'dissipate' into space? Is it by (a) convection, (b) conduction or (c) radiation?

2. Does convection have (a) a warming effect on the Earth or (b) a cooling effect on the Earth?

 

[Balbi]

Due to the amazingly large amount of space and the comparably tiny bit of earth, why aren't we a rather interesting novelty snowball?

 

[bigfish]

Bigfish, my old matey, two simple, straightforward questions for you.

1. How does heat 'dissipate' into space? Is it by (a) convection, (b) conduction or (c) radiation?

As Richard Lindzen points out in the link provided above, "air currents [convection] bodily carry heat to regions of diminished infrared capacity where the heat is radiated to space—balancing absorbed sunlight."

2. Does convection have (a) a warming effect on the Earth or (b) a cooling effect on the Earth?

A cooling effect, obviously. The amount of heat left to straightforward radiative absorption (the component critical to the manmade warming hypothesis) is very small, less than 5%. That means that about 95% of the heat is transferred by conduction and convection, not radiation picked up by "greenhouse gasses".

Heat transfer by convection (+conduction) ~95%

Heat transfer by radiative absorbtion ~5%

Scientists have been saying, with no disagreement, that the atmosphere is responsible for heating the globe by 33°C. Propagandists (promoters of a supposed consensus view that humans are the cause of global warming) try to create the impression for the public that all 33 degrees is caused by "greenhouse gasses". It's not true.

 

[WouldBe]

[/CENTER]

Scientists have been saying, with no disagreement, that the atmosphere is responsible for heating the global by 33°C. Propagandists (promoters of a supposed consensus view that humans are the cause of global warming) try to create the impression for the public that all 33 degrees is caused by "greenhouse gasses". It's not true.

Yet that diagram clearly shows that the larges amount of radiation reaching the earth comes from 'back radiation' from greenhouse gasses. Oops.

 

[bigfish]

Yet that diagram clearly shows that the larges amount of radiation reaching the earth comes from 'back radiation' from greenhouse gasses. Oops.

The diagram is there to illustrates the process. The heat transfer values in the graph come from Stephen Schneider, a well known advocate of the violation of scientific principles and ethics in pursuit of ideological ends. The graph (not to mention Schnieder) is a big favourite of Bernie Gunther's.

http://www.urban75.net/vbulletin/showpost.php?p=5110787&postcount=39

 

[Knotted]

As Richard Lindzen points out in the link provided above, "air currents [convection] bodily carry heat to regions of diminished infrared capacity where the heat is radiated to space—balancing absorbed sunlight."



A cooling effect, obviously. The amount of heat left to straightforward radiative absorption (the component critical to the manmade warming hypothesis) is very small, less than 5%. That means that about 95% of the heat is transferred by conduction and convection, not radiation picked up by "greenhouse gasses".

Oh, fer chrissake! When in a hole stop digging. Lindzen clearly states that the "heat is radiated to space". He's not an idiot. When you talk about 'straightfoward radiative absorbtion' are you talking about radiation from the earth into space or the ground into the atmosphere? You can't have it both ways.