The Energy Balance and the Greenhouse Effect: 1 of 3


In the previous article I explained the Earth’s energy balance in terms of NET energy transfers.  I was surprised by the response that this did not explain the Greenhouse Effect (GHE).  It actually explains the GHE in a simpler manner than any other method.  Just to be clear, this site fully supports the GHE of the atmosphere of 33 °C.  Without the atmosphere moderating the energy coming from the sun, the surface would vary between a blistering hot and deadly cold.  The GHE takes that energy and evens it out.

Now I will show that NET energy transfers accurately show the warming of the atmosphere that is routinely seen on a daily basis.  Using the mass profile of the atmosphere  and the heat capacity it is possible to estimate the amount of warming that will happen based on the overall heat transfer from the surface.

The Inconvenient Skeptic

Average mass (kg) for each km of the Troposphere

The reason that I focus on the Troposphere is that is where most of the atmosphere mass is.  More than half the mass is contained in the first 6 km of the atmosphere.  Slightly more than 80% of the atmosphere’s mass is contained in the first 12km of the atmosphere.  Since it contains most of the mass, it will also contain most of the atmosphere’s energy.

The NET energy transfer from the surface to the atmosphere is 120W/m2.  This translates to 10,368 kJ day/m2.  If only that energy could be converted to electricity then there would be no reason to debate CO2 emissions, but I digress.  The surface area of the Earth is ~510,072,000,000,000 m2.  So each day the surface transfers 5.29E18 kJ of energy to the atmosphere.  Here is the temperature change that amount of energy would cause based on the total mass of the atmosphere up to each altitude.  I did assume a constant heat capacity.

The Inconvenient Skeptic

Temperature change caused by the daily NET energy transfer

So if the energy was all transferred to the 1st km of atmosphere, the temperature would increase a bit over 9 °C.  All the energy from the surface leaves at the top of the Troposphere.  So the top of the Troposphere is causing cooling and the bottom is causing warming.  If the Troposphere is split into two six km parts, then the effects of the cooling and the heating are applied for each half of the troposphere, then the average daily increase in temperature caused by energy transfer from the surface to the atmosphere would be 2.0-2.6 °C.

The actual measured average temperature change each day varies by lots of conditions, but as shown by Geerts, 2002 the average daily difference between the min and max temps are in the 2-3 °C range.  This value is lower than most people expect, but that is mainly due to the oceans that have small night and day differences.  What this does show is that 120 W/m2 gives the lower 3-5km of the troposphere the amount of energy needed to explain the average daily changes in temperature.

Here is what the overall energy transfer model looks like for the Troposphere.

The inconvenient Skeptic

(Red) Shortwave from sun, (Orange) Longwave from surface and atmosphere, (Blue) Latent Heat from water, (Pink) Convection or Thermal heat transfer

If the atmosphere did not absorb energy from the surface then the Earth transfer far more energy straight into space.  The 40 W/m2 that currently goes to space would grow to 240 W/m2 and the others would go to zero.  If the surface was sending 240 W/m2 straight to space, the temperature of the surface would be 255K or -18 °C.  I will borrow from another site for this picture as it is correct in what would happen.

The Inconvenient Skeptic

Without the Atmosphere

The next step will be to discuss different situations of the Greenhouse Effect and the energy transfer rates.

Posted in Energy Balance by inconvenientskeptic on November 30th, 2010 at 6:50 am.

21 comments

This post has 21 comments

  1. Malaga View Nov 30th 2010

    The Diurnal Bulge and the fallacies of the “Greenhouse Effect”

    http://www.spinonthat.com/CO2_files/The_Diurnal_Bulge_and_the_Fallacies_of_the_Greenhouse_Effect.html

    The Earths atmosphere, which consists of 99% Oxygen and Nitrogen, is incontrivertably heated from the top down. There is no “Greenhouse Effect” in our atmosphere and therefore no “Greenhouse Gases”. The concept is bogus and simply does not exist. It never has and it never will.

  2. inconvenientskeptic Nov 30th 2010

    Nope. That is very, very wrong. There are correct facts intermixed there, but no.

    Instead of going over the whole thing I will simply point you to: Corona.

    It is 3,000,000K vs the suns surface at 5,800K. It is also vacuum, much like the atmosphere above 100km. The temperature is high, but you would freeze in that atmosphere of 1200K as there is no energy.

    High temp vacuum doesn’t warm anything. There is so much else wrong there….

  3. John, I’m curious as to where you think your disconnect NASA’s proof of global warming lies.

    Here is the link again in case you have lost it:
    http://climate.nasa.gov/evidence/

    Do you think that A.) you are smarter than the scientists at NASA, or B.) that NASA is involved in some sort of conspiracy in which global warming theory benefits them?

  4. inconvenientskeptic Nov 30th 2010

    Boo,

    Lies is a very strong word. I have never said that they are lying. Nor am I the only one saying they are incorrect in their conclusions. There are many scientists and engineers that disagree with AGW.

    I agree that CO2 emissions have increased CO2 levels. As I have stated here and here. I think ocean temperatures dictated CO2 levels in the past. Not that CO2 levels controlled temperature levels.

    I have discusses all of those topics with far more detail than the NASA site has. Please take a look and point out specifics that you disagree with by topic. This is a large topic to say the least.

  5. Boo – do you cite authority because you lack the will to do your own thinking or is it just the inability to undestand scientific principles?

  6. Malaga View Nov 30th 2010

    This is a large topic to say the least.
    That really is an understatement… there are so many building blocks used to create the pyramid upon which the Energy Balance rests… and checking each step of the way is virtually impossible for the average joe.

    I am also becoming increasing concerned about the average insolation concept used in the Energy Balance… the solar constant is about 1364 W/m2… and land based measurements are said to peak somewhere around 1000 W/M^2. That seems to be a whole different ball game to explaining away 341.3 W/m2.

  7. inconvenientskeptic Nov 30th 2010

    Malaga,

    In one of the next posts I cover the switch from 1364 to 341 W/m2. 1/4th is the ratio between the area of a circle and the surface area of a sphere. A point perfectly perpendicular to the sun will get close to 1000 W/m2, but averaged out over the Earth it is 1/4th the solar constant.

  8. John, you didn’t really answer my question.

    Is NASA involved in some sort of conspiracy that behooves them to state that global warming is real or are you just smarter than the scientists at that government agency?

    There are so many brilliant scientists that work at NASA. Don’t you think at least some of them would speak up if any of their conclusions were incorrect?

  9. inconvenientskeptic Nov 30th 2010

    I did answer. They are incorrect in their conclusions. There are two sides to the scientific debate. Politicians are the ones that twist science to other things.

  10. John, if NASA’s conclusions are incorrect then why don’t you get in touch with them and have them correct their website?

    I’m sure that if you really have evidence that can refute their claims then they would be more than willing to change their stance on the subject.

  11. Malaga View Dec 1st 2010

    Thanks for the response… I can understand the mathematics behind the average… but there are a number of things that really bug me about this approach that has been adopted by Trenberth et al. So please forgive my rant below… I am not expecting a reply… I just need to let off some steam 🙂

    Firstly:
    Is there an actual location on the earth that actually conforms to this average? Or more specifically: Where on the earth do we go to take actual measurements to test the hypothesis? It is like the “average temperature” concept… it doesn’t apply to my habitual geographic location… it always applies to somewhere else… and by implication nobody else can verify the figures with actual observations taken where they live … this is really a very clever trick that disconnects the science from reality.

    Secondly:
    The Energy Balance varies all around the globe… we have artic winters that receive no insolation… we have ice sheets that reflect huge amounts of sunlight… we have oceans… we have continents… we have equatorial rain forests which absorb huge amounts of solar energy and release huge amounts of water into the atmosphere.. and there are weather systems that help distribute the heat around the globe. This implies that studying the average will not really help us understand what is going because nowhere really conforms to the average model. The Energy Balance is driven by the extremes… cold poles… and a hot equator… with the mid-latitudes sandwiched between the extremes. Therefore, the average energy balance being described is always missing two energy flows… heat arriving from the equator… and heat being dispatched towards the pole… and I doubt this is a zero sum flow… this flow drives weather events at the average location that affect the energy balance… so this releases energy as the heats is moved away from the equator. So again, this is really a very clever trick that disconnects the science from reality.

    Thirdly:
    My most fundamental problem with the average approach is that it is totally misleading… it understates insolation at the equator… and it overstates insolation at the poles… so the individual energy flows have huge variability… we don’t know if the flows vary in a linear fashion… we ignore any heat sinks… we ignore weather… and we don’t know if average flow model is applicable / consistent with either of the extremes… So again, this is really a very clever trick that disconnects the science from reality.

  12. Inconvenientskeptic

    You make the same mistake as many others with your incorrect assertions.

    THE TAIL DOES NOT WAG THE DOG.

    The Thermosphere is the Diurnal Bulge. In other words, there is no thermosphere on the dark side of the Earth. Therefore the tail does not wag the dog!

    The thermosphere exists because of Solar heating. It makes no difference if you would freeze in such a thin atmosphere despite temperatures of 1200º C. Of course the Air is so thin you would freeze but if it were not for the heating from incoming electromagnetic radiation there would not be a 600 km hight bulge of atmospheric gases under the solar point in the first place.

    Once again, THE TAIL DOES NOT WAG THE DOG.

  13. inconvenientskeptic Dec 2nd 2010

    Will,

    Are you referring to the top comment that states the atmosphere is heated from the top down?

    If so then your comment would be that the thermosphere causes warming only during the day and when it dissipates at night the Earth cools down.

    I want to make sure I understand what you are saying before replying.

  14. Malaga View Dec 2nd 2010

    Without the atmosphere moderating the energy coming from the sun, the surface would vary between a blistering hot and deadly cold. The GHE takes that energy and evens it out.

    So the atmosphere is a heat sink… during the day it is warmed by sunlight, thermals, evaporation and back radiation… and during the night the earth is heated by back radiation from the atmosphere – especially on cloudy nights.

    I am OK with this at a high level… it is when we get down to the role of the green house gases that everything gets a bit murky… especially with regard to CO2 and global warming.

    I took a look at Wikipedia to check how much CO2 is in the air at http://en.wikipedia.org/wiki/Air and the answer is 0.039%

    The remainder of the atmosphere is mainly Nitrogen (78.084%) and Oxygen (20.946%) plus a mix of other trace gases.

    I was wondering… if it is a hot and sunny day and the temperature outside is reading 80F then how hot does the CO2 (0.039%) have to become to raise the other 99.961% of the air by on tenth of a degree F?

    My back of an envelope calculation went like this:

    80 + ((99.961 / 0.039) / 10) + 0.1 = 336.41 F

    And this probably means that the CO2 has gone shooting up in the atmosphere long before it gets a chance to heat the rest of the air.

    Which leads me to think that green house gases can hardly make any difference to near ground air temperatures… it just does not seem possible.

  15. John,

    No I am not saying that the thermosphere heats anything. That is what I said in my comment.

    Why are you trying to put words in my mouth?

    “If so then your comment would be that the thermosphere causes warming only during the day and when it dissipates at night the Earth cools down.”

    Please read my comment more carefully, then perhaps you will not have to re-enterperate my words.

  16. inconvenientskeptic Dec 2nd 2010

    Malaga,

    The next two parts of the series will cover this more extensively. The next one will be out tomorrow. CO2 is only a part of what warms the atmosphere. On the time scale of 1 second CO2 is never warmer than the rest of the air. When it absorbs energy, the molecules around it collide and re-distribute the energy. CO2 contributes only 3% of the total energy transfer from the surface to the atmosphere.

    Hopefully by the end of part 3 this will all make more sense.

    Will,

    I read your post several times and it isn’t clear to me if you were responding to the earlier comment or not. If you could re-phrase I am hoping that it will help me understand what you are saying.

  17. Glenn Tamblyn Dec 3rd 2010

    John

    I have addede a large comment to the original post on Energy Balance. I will let you post your 3 sub posts before commenting further.

    Readers here might like to look at my comments on the earlier post.

    Glenn

  18. Glenn Tamblyn Dec 3rd 2010

    Further to your comment to Malaga

    “CO2 contributes only 3% of the total energy transfer from the surface to the atmosphere. ”

    No.

    It contributes something like 67% of the total energy flow from the surface to the atmosphere and 0% to the energy transfer from the atmosphere to the surface. Using your NET approach masks the effect, not elucidates it. See my other posts

    Glenn

  19. John,

    Does the top comment by Malaga View refer to the Diurnal Bulge?

    Does my initial comment refer to the Diurnal Bulge?

    Does this help you understand anything?

    My website http://www.spinonthat.com/CO2.html has been removed sometime in the last 12 hours for some unknown reason. So the link at the top is out of action.

  20. It is back up now. All links are working again.

  21. Craig Goodrich Dec 6th 2010

    Boo,

    I looked at NASA’s “evidence” page. The only evidence they mention for CO2 increase causing recent warming was the IPCC’s AR4. The only relevant part of AR4 is WG1, Chapter 9 on attribution.

    Careful reading of that chapter (slogging through around 90 pages of really dense prose) reveals that there is no actual evidence presented or referenced there, either.

    So where is the actual evidence for this hypothesis, which appeared implausible more than two decades ago and has since been disconfirmed by every actual measurement anyone has made?

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