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jim m
Lv 5
jim m asked in EnvironmentGlobal Warming · 9 years ago

Is the basic question: Why is our planet ~25 degrees warmer than black body law indicates?

Just following up on the latest Maax question. Why is it assumed the atmosphere is causing this bone of contention? Why not look a bit deeper into this detail?

Update:

Richard B, When measuring Earth's temperature from space IR radiation is used right? A direct reading of Earth's surface can be made on a clear day, but, on a cloudy day the reading will be false? (or not)

Update 2:

Jeff M, Venus is quite bright too because most of the solar energy that planet receives is reflected. As for way Earth is 33 degrees warmer than black body law indicates I disagree with your conclusion.

Update 3:

Jeff M, There is no need to rewrite physical law or add to it in any way. You have misunderstood something I posted I guess. Maybe you could explain what it is I said that effects laws.

Update 4:

pegminor, Well I'm sure you won't claim everything is already known and you guys know it all. I know the atmosphere is an effective modulator of energy, but, there are limits to what it can do. The atmosphere cannot store energy for more than a few minutes and if it was not resupplied at a constant rate it would cool down. Simply saying everyone who sees what you don't see is uninformed might make you feel good, but, it doesn't educate.

Update 5:

All you guys out there, First, it's nice to see progress being made. We have several lines of thinking that at least are reasonable and logical and there is good agreement on basic law. We have a good comparable in the moon. Why not determine how Earth would be(thermodynamically speaking) if it had no atmosphere? The reason is that Earth would not be anything like the moon even without the atmosphere. Of course we need to over look the fact the ocean cannot exist without the atmosphere. We can do that.

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  • Anonymous
    9 years ago
    Favorite Answer

    the law of radiation vs temperature is fundamental to physics as we understand it

    a space scientist observing earthy radiation would easily calculate its average temperature

    the correct Q is : why is the surface temperature of the earth so different from temperature of the moon which is the same distance form the earth and gets the same solar energy?

    and YES "the devil is in the details" we know something but not much about climate and energy exchange on earth

    Venus is only a little closer to the sun but is over 700 deg F and would melt lead

  • 9 years ago

    There is no bone of contention. There simply are no reputable scientists that don't believe in the atmospheric greenhouse effect. Feel to pick any of the "denier" scientists: Richard Lindzen, William Gray, Roy Spencer, Fred Singer, etc., and you will find that every one of those guys believes in the atmospheric greenhouse effect also.

    The only guy I've heard that even tries to dispute it is some German guy without a Ph.D. that published his "paper" on a blog. It consists of various standard equations connected together by gibberish.

    EDIT: I'm not really sure what you're claiming is a bone of contention then. The sun is the ultimate source of energy in the Earth's atmosphere, and once an equilibrium is established, then the amount of energy coming in from the sun will be balanced by the amount being radiated away by the planet. With no greenhouse gases the Earth's radiative temperature would be one number, with greenhouse gases it is a different, higher temperature. The atmosphere doesn't need to "store energy" at all, it just takes some of the energy that would have escaped off into space and redirects back toward the Earth's surface, and makes it warmer than it would have been otherwise.

    If you have some basic training in physics (a little thermodynamics, Stefan's Law, blackbodies) I could give you a simple problem that would demonstrate the effect, in a very idealized example.

  • Jeff M
    Lv 7
    9 years ago

    It's 33-34 degrees warmer. CO2 has known radiative effects as does every other greenhouse gas. These gases are known to absorb specific frequencies of radiation within the Earth's black body radiation curve. These gases have to provide some heat retention. If you are claiming they provide none then you're going to have to prove that there is no radiation that these gases can absorb within the planets black body radiation curve. You're also going to have to explain why as what you are attempting to explain goes against fundamental physical laws. If you are attempting to show that the amount of radiation attributed to the greenhouse effect is small and the rest is being retained by some other mechanism then you're going to have to show what that other mechanism is.

    RichardB: Mercury is even closer to the Sun yet Venus is much warmer.

    jimm: I think you're going to have to go into a lot more detail on why you disagree with my conclusion. I mean what you're doing in your mind is rewriting known physical laws. Explain. And I am aware Venus has an incredibly high albedo.

    Edit: Your contention is that something else is causing the warming other than an increasing greenhouse effect correct? Greenhouse gases of various types have been measured to be growing in the atmosphere. This corresponds with the specific frequencies those greenhouse gases absorb at and the decrease in outbound radiation at those frequencies. You are stating that it may be caused by something else and to look deeper. I said that you're going to have to describe and explain what you state is causing the warming with real world measurements showing that it is the cause. You are also going to have to show why, though all measurements show to coincide with increased heat retention by greenhouse gases, why your warming factor has the same effect.

  • Anonymous
    9 years ago

    The greenhouse effect in the atmosphere is very important, but so is albedo. When you park two cars, same make model and year, one black and one white next to each other in a sunny parking lot, the difference between the black car and the white car is albedo.

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