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Viewing Single Post From: The giant space ship example

So we settled on Dwarf heat as getting 5.4e15 watts and Earth heat is disputable but receives 1.74e17 watts of sunlight. Roughly Dwarf is getting 20-30 times less heat then earth.

Earth surface area is 510 million sq km
Dwarf surface area is 4 pi r 2 or 18 million sq km or 1/28th the area of earth. About twice land area of US, btw.
Roughly Dwarf is getting same heat as earth does. And dwarf surface air temperature is on average 5 K cooler.

One thing we could have done is start the dwarf at a temperature comparable to earth without greenhouse effect. One way would be the commonly stated -33 C [so a -18 C average temperature].
Or instead could start with Earth as blackbody without the "Visual geometric albedo: 0.367" included. Or as Wiki says:
"If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth is, it would have a temperature of about 5.3 °C. However, since the Earth reflects about 30% (or 28%) of the incoming sunlight the planet's effective temperature...is about −18 or −19 °C".

So starting temperatures could have had the dwarf start at 5.3 C or -18 to -19 C.
If add greenhouse affect to a 10 C dwarf, the dwarf should be warmer than Earth.


I think our assumption refutes "greenhouse effect" as described in Wiki.
In that greenhouse gases increase earth temperature by 33 C.
This because roughly our dwarf planet receives about same warming that earth receives per sq meter, it doesn't have greenhouse gases and it's 10 C.
But this is not saying the model of dwarf refutes AGW or CAGW but rather indicates the greenhouse effect from greenhouse gases doesn't cause planet to be 33 C on average warmer.
That instead much of this warming is reducing night time losses that that is caused by heat capacity.
In practical terms this means the greenhouse gas don't need to come up with "the missing" 33 C.
Instead it could mean they have to account for say 5 C of warmer.
This in a real sense could make more of a case for CAGW- because to add a degree could take less greenhouse effect from greenhouse gases.
Or it doesn't provide any difference in this regard, but does make "finding" warming affect for greenhouse gases "easier"

Or suppose we put the dwarf planet at Mars distance. What Mars average would be is whatever number, but night time mars isn't going to cool- it would lose less than 1 C. And most people would call that due to the "greenhouse effect" of the dwarf atmosphere [which has no "greenhouse gases"].
Edited by gbaikie, Dec 9 2011, 10:48 PM.
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The giant space ship example · Physical theory for climate