FAQ – a general answer to questions about the greenhouse effect
As linked off the www.ilovemycarbondioxide.com/carbondioxide.html page, here are helpful explanations to some of the questions I've received. The combined mechanisms of radiative input from the sun, constant convective plus conductive heat loss through the atmosphere, and finally radiant energy loss to the vacuum of space, are perhaps too complex to understand in one session. But it is becoming more and more clear how the IPCC has bamboozled policymakers the world over: they are themselves bamboozled! They themselves believe their own "theory", one that's too convoluted for some skeptics to follow and which other skeptics endorse. Hollywood is a strong driver of false perceptions about space. Unfortunately, too many people don't think twice about the fiction in science fiction and take what they see in movies as the truth.
Is this Hans Schreuder lying?
The model he describes is accepted and taught in colleges the world over. Gavin Schmidt of NASA uses the same example to explain the greenhouse effect to his readers.
(Taken from http://courses.washington.edu/pcc588/lectures_2008/588_lect_010708.pdf)
To the left of the dotted line is incoming solar radiation. Of an initial 342 Watts per square meter (W/sqm) beamed at the earth, 102.6 are rejected and sent back to space, resulting in the earth absorbing 239.4 W/sqm. To the right is outgoing — er, and also incoming — terrestrial radiation. It is understood that outgoing terrestrial energy must equal incoming.
The atmospheric function f plays a key role here. It represents the atmosphere’s efficiency at intercepting terrestrial emission. As f rises, direct terrestrial emission to space necessarily declines. But, since atmospheric absorption increases as direct surface emission decreases, it performs the job of radiating the difference. This ensures that energy out equals energy in. On the other hand, what the atmosphere has absorbed from the surface also gets emitted back to the surface.
For instance, call terrestrial emission 240 W/sqm instead of 239.4 and picture a 50/50 scenario.
The surface will emit only 120 W/sqm to space because half is caught by the atmosphere. The atmosphere emits the 120 W/sqm it has absorbed, bringing the earth to "radiative equilibrium." But that 120 W/sqm is also radiated down to the surface, raising surface energy to 240 plus 120, i.e., 360 W/sqm, quite a bit warmer now. A little more tweaking and you can get the surface to the requisite 390 W/sqm, enough to bring the earth's calculated average temperature to 15 degrees Celsius.
If people are gullible enough to believe such a scenario, and apparently millions do, they deserve what’s coming down the road at them. Yet this is what even many climate skeptics call "the basic science."
Substitute glass for that layer of "greenhouse gases." Like them, glass is also transparent to visible light but largely opaque to what’s called thermal infrared. Direct a radiant heater at a glass pane, then. According to greenhouse physics, you now have the equivalent of two radiant heaters because the glass will absorb, say, 500 W/sqm from the heater and emit that to the surroundings but also radiate 500 W/sqm in the other direction, back to the heater. 1000 Watts per square meter in all.
This is what Schreuder means by counting energy twice. But in fact it’s more. Because remember that the radiant heater will be heated by its own re-directed energy and thereby emit even more energy — which the glass will absorb and double, which will heat the heater more... It’s a perpetual motion machine, just as he says.
That such a childish fantasy threatens to destroy western civilization is incredible, but that's exactly the case.
(Taken from http://unfccc.int/essential_background/feeling_the_heat/items/2903.php)
- The relationship between so-called greenhouse gases and atmospheric temperature is not yet well understood. So far, climatologists have hardly participated in serious scientific discussion of the basic energetic mechanisms of the atmosphere. Some of them, however, appear to be starting to realise that their greenhouse paradigm is fundamentally flawed, and already preparing to withdraw their theories about the climatic effects of CO2 and other trace gases. [...] This is no surprise, because in fact there is no such thing as the greenhouse effect: it is an impossibility.
- To support their argument, advocates of man-made global warming have intermingled elements of greenhouse activity and infrared absorption to promote the image that carbon dioxide traps heat near earth's surface like molecular greenhouses insulating our atmosphere. Their imagery, however, is seriously flawed.
A greenhouse is simply a physical structure that traps hot air. Solar radiation initiates the heating sequence inside a greenhouse when photons in the visible region of the electromagnetic spectrum, entering through glass or transparent plastic panels, are absorbed by surfaces of opaque objects. Reflected photons exit freely; neither they, nor their "heat," are trapped inside. Drivers who regularly park their mobile greenhouses in sunny locations exploit this principle by placing reflective white cardboard behind their windshields to expel some before they're absorbed.
The second law of thermodynamics prohibits carbon dioxide from arresting or reversing the spontaneous downhill flow of energy, putting advocates in the awkward position of insisting that a trace atmospheric component's innocent participation in a natural heat dissipation process is responsible for warming a planet. The fictitious "trapped heat" property, which they aggressively promote with a dishonest "greenhouse gas" metaphor, is based on their misrepresentation of natural absorption and emission energy transfer processes and disregard of two fundamental laws of physics.
Their promotional embellishments have also corrupted the meaning of "greenhouse effect," a term originally relating the loose confinement of warm nighttime air near ground level by cloud cover, to hot air trapped inside a greenhouse.
Greenhouse comments by Alan Siddons:
One thing that passes unnoticed by greenhouse believers is that water vapor plays quite a role in keeping the planet cool by absorbing incoming radiant energy. The blue line below is what we’d get without an atmosphere, yellow line what we get with it. Sunlit temperatures on the earth’s surface are substantially less than those on our neighbor the moon because our atmosphere intercepts incoming radiation. Given the conservation of energy law, "greenhouse gases" cannot add heat to the earth’s surface, but they can certainly reduce it.
(http://faculty.engineering.ucdavis.edu/jenkins/courses/EBS216/SolarEnergy/SolarEnergy.pdf pg 9.)
The premise of greenhouse theory is that "greenhouse gases" absorb infrared energy while regular air does not. So the infrared emitted by "greenhouse gases" doesn’t get absorbed by the air; supposedly it passes right through to the earth. This would seem plausible because, as Norm Kalmanovitch’s estimates indicate, these trace gases would have to be at incredibly high temperatures in order to heat the air conductively. Radiant transfer to the earth is thus the remaining option.
If, however, the earth is heated by the sun and also by the radiant transfer performed by trace gases, then its surface temperature must necessarily be higher than the temperature the sun could make it, due to the extra radiant energy impinging on it at any time of the day. Yet the simple fact is that the earth’s sunlit surface temperature is perfectly consistent with solar irradiance alone. Ergo, greenhouse theory is demonstrably false. Radiant energy from trace gases cannot heat the air, nor does it heat the earth.
Remember that retaining heat is not enough to raise the earth by 33 degrees Celsius. The old greenhouse theory proposed a blanket. The new greenhouse theory demands an electric blanket.
The fantastic premise of greenhouse theory is that an ideally hot object, a blackbody, is but a baseline that atmospheric infrared-absorbers are somehow able to surpass. To the contrary, though, a blackbody defines the maximum temperature an object can reach as a result of absorbing radiant energy. No evidence exists that infrared-absorbers ("greenhouse gases") are capable of raising the earth's temperature ABOVE the limit set by the amount of radiant energy available.
Think of pouring hot coffee into an absolutely perfect thermos. At the moment of doing so its temperature is fixed: it will rise no higher, nor will it fall. The reflective coating in the thermos ensures that no radiant energy ("heat waves") from the hot coffee will be emitted and the vacuum in the thermos ensures that no heat is lost by contact with other objects.
Aided by a mirror and a vacuum, the coffee’s temperature stays constant, the same result as having X amount of radiant energy impinging steadily on it. A perfect thermos wouldn’t let heat pass conductively to the glass; ergo, there’s no such thing as a perfect thermos. But if there were, radiant energy couldn’t escape because all the infrared ("heat waves") would be reflected back. So what’s the difference between X amount of radiant energy going nowhere and X amount steadily shining on an object? None. The result is the same. No temperature change.
The greenhouse scenario as depicted by the IPCC has the earth receiving a constant amount of radiant energy, thus reaching a certain temperature. But imagine the earth enclosed in a 100%-efficient mirror, like coffee in a perfect thermos. Can the earth’s temperature then rise HIGHER? No. The mirror merely helps sustain the temperature it has reached.
As for the second detail, the IPCC and other authorities commit the same error that most people do. Presupposing that space is incredibly cold, they surmise that the earth must be kept warm by an atmospheric blanket which inhibits the radiant energy emitted to space – an outmoded conjecture disproved by satellite observations. Despite evidence to the contrary, then, belief in "the greenhouse effect" persists, for people feel that earth needs to be isolated from the "coldness" of empty space.
Yet the earth is actually enclosed in a perfect thermal insulator, the vacuum of space itself. Short of installing a gigantic mirror around our planet, nothing but space can preserve the earth's temperature longer.
Thus the value of understanding how a thermos works.
"Really new trails are rarely blazed in the great academies.
The confining walls of conformist dogma are too dominating.
To think originally, you must go forth into the wilderness."
S. Warren Carey
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