OohPooPahDoo
Gold Member
It probably is easier to calculate/model - fewer variables.OK. Maybe I'm wrong about what you are saying, but my understanding of the term "backradiation" is the radiation by the Earth's surface after absorbing radiation from the sun during the day - it's IR radiation (heat) that it emits as , what I understand to be, backradiation.
As you can see from the discussion above, CO2 absorbs a bit of that IR radiation, converts it to kinetic energy, which generates heat, of course. So, because the CO2 is generating heat, not much, but some, the heat from the Earth (what I understand to be backradiation) does not flow as much. Heat transfer is dependent upon temperature gradients, so that heat transfer (Earth back to space) is slowed.
So, without GHGs, we would lose much more heat during the night than we do.
That is my understanding of the term, backradiation. Of course, because of the misnomer "Greenhouse Effect", I could be completely wrong. Climate scientists have been know to use terms that have little to do with reality.
If I misunderstand you, please correct me.
That's an interesting question - how cold would the Earth get at night time with no greenhouse effect?
Will see if that's easily calculable.....
So, I just did a search of the backradiation term as it applies to the climate and I saw a cartoon that indicates the 'flows' of radiation. The backradiation arrow is toward earth. I would imagine that this is to indicate the heat generated from the CO2. Smaller flux, but still slows the flux of blackbody radiation from the Earth at night.
I still don't see any problem with that. Similar concept.
Edits:Good examples.EDIT1: Off the top of my head the answer is not much. The Earth is a huge mass and has a lot of thermal energy, and the amount that can radiate at night is tiny compared to that.
EDIT2: Yet night and day on the moon are very different temperatures. They are very different on Mercury, too, but that's because mercury is tidally locked so only one side is exposed to the sun all the time and the other remains night. Hmmmmm
I am not seeing much problem with what is described as the "Greenhouse Effect", except the name, of course. Grrrrrr.
The name is at least roughly correct. Radiation enters a greenhouse, generates heat, and the heat is trapped. The trapping mechanism is just different - one traps the actual hot air, the other traps the radiation