Apocalypse recalculated – whatever happened to ‘Back Radiation’?

Posted: June 14, 2010 by tallbloke in Astrophysics, climate

NASA has kindly provided us with a new Earth Energy Budget diagram:

Earth Energy Budget

Which looks a lot like the old Keihl-Trenberth diagram, with snazzy colours.

But, wait a minute! What happened to ‘Back Radiation from the atmosphere’?? We have long been told of the impending apocalypse due to Co2 in the atmosphere increasing due to our emissions from our cars, homes, energy plants etc causing more heat to be re-radiated from the atmosphere back to earth.

Here’s the old diagram:

Keihl-Trenberth energy budget

See over on the right there, 324 Watts per square metre of back radiation from ‘Greenhouse Gases’. Where’s it gone?

Maybe it has something to do with the discovery by a trio of scientists that NASA gave up using the Stefan Bolzmann equation when they did the moon landings. Martin Hertzberg, PhD, Consultant in Science and Technology, Hans Schreuder, retired analytical chemist, and Alan Siddons, former radiochemist discovered NASA already knew the Moon absorbs a lot of heat and gives it up later, the daytime surface temperature turned out to be 20 degrees lower than expected, and the night-time temperature 60 (yes 60 Kelvin) degrees higher than expected from simple black body equations. See the paper ‘A Greenhouse Effect on the Moon?’ here.

I wonder why NASA never told the climate scientists…

I have been saying for a long time now that the oceans absorb a lot of energy direct from the sun (not from ‘back radiation’, as the longwave doesn’t penetrate the oceans surface beyond it’s own wavelength) and releases it when solar activity is low. The new figure of 51% of the sun’s radiation incident on the Earth being absorbed by the land and oceans means there is quite a few Watts/m^2 more than previously thought. I’ll need to revisit my calcs as this will affect my climate sensitivity calculations.

Assuming NASA still agree with Keihl and Trenberth’s figure for total insolation to the top of the atmosphere, here are how the new percentages compare to the old Watts per square metre figures:

Incoming shortwave  solar energy:
Total insolation arriving at top of atmosphere: Old: 342 New:342
Absorbed by surface: Old:168 New:174 Diff: +6
Absorbed by atmosphere: Old:67 New:55 Diff: -8
Absorbed by clouds: Old: zero New:10 Diff: +10

Outgoing shortwave  solar energy:
Reflected by clouds, atmosphere (inc aerosols): Old:77 New:89 diff: +12
Reflected by surface: Old:30 New:14 Diff: -16

Incoming longwave from atmosphere:
From greenhouse gases: Old:324 New: zero Diff: -324 !!!!!!!!!

Outgoing longwave infrared energy:
Radiated by Surface: Old:390 New:72 Diff: -218 !!!!!!!!!!
Thermal conduction: Old:24 New:24 Diff: zero
Latent heat of evaporation: Old:78 New:78 Diff: zero
Radiated by clouds and atmosphere: Old:195 New:219 Diff: +24
Radiated direct from surface through ‘atmospheric window: Old:40 New:21 Diff: -19

I’ll put the figures in a spreadsheet and do some totals when I get a minute. One thing is for sure, the science isn’t settled. Here’s what Kevin Trenberth said in private email released with the rest of the ‘climategate’ material.

“The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t.”

Indeed Kevin, indeed. Maybe a few hours spent understanding the energy absorbative capacity of water relative to long and shortwave radiation might help?

  1. P.G. Sharrow says:

    Nice looking up grade, I use a tan background as the white is too bright to me. pg

  2. tallbloke says:

    Heh, hi P.G.
    I was considering going over to Anthony’s old wordpress theme now he’s changed it. Or did you mean NASA’s shiny new Earth Energy Budget diagram’s background? 🙂

    Edit: I found a grungy new theme. Is that a bit easier on your eyes P.G.?

  3. Willis Eschenbach says:

    If you sum up the net flows in the Trenberth diagram, you’ll get the other diagram. This is because we can show things as either net flows or individual flows.

    Here’s an example. Suppose I give you $100, and you give me $75. There are two equally valid ways to consider this exchange:

    (If that doesn’t show up, the file is at

    http://homepage.mac.com/williseschenbach/.Pictures/all_flows_net_flows.jpg )

    As you can see, the net flow is in one direction, but there are individual flows in both directions. The same thing occurs with radiation. The net flow always goes from warmer to cooler, but that doesn’t mean that there is no flow from cooler to warmer. One of your diagrams shows net flows, the other shows individual flows.

  4. tallbloke says:

    Hi Willis,

    I know, I know. The post is to some extent done ‘tongue in cheek’. There is a scientific reason why though. I want to highlight the developing rift betwen NASA and the ‘Team’ regarding the orthodoxies of climate science we’ve come to know and distrust.

    The Team claims that the Earth is 33C warmer than it would be without an atmosphere, according to the Stefan-Boltzmann equations. My point is, NASA has had empirical evidence that the Moon is 40C warmer than it should be according to the Stefan Boltzmann equations for nigh on 40 years. There ain’t no atmosphere on the Moon to provide a 40C greenhouse effect though. NASA knows this, hence their reluctance to add the flows onto their energy budget diagram. They don’t want to tread on the toes of the climate science the govt is relying on to raise $$$, because they get those $$$ in funding. But at the same time, they are tired of being branded as charlatans by sceptics they know to be correct in their criticisms. See the post on SDO below, and the one on Miscolzci.

    The Stefan-Boltzmann equations were never designed to deal with rotating spheres composed of energy absorbant materials with bloody great big heat sources on one side of them. Nor did they claim they were.

    So, the amount of energy supposedly being re-radiated to earth from the atmosphere is derived from an unsuitable equation which doesn’t fit the observed data anyway. Hence the infamous ‘energy gap’ inthe Earth’s energy budget written about by the oceanographers at Southampton University, but never, ever, ever mentioned by the Team, except in private emails.

    The killer punch is that if the amount of back radiation is substantially lower than the Team claimed (which it is) then the climate sensitivity would have to be ludicrously high to get co2 to do it’s thang and raise temps by an amount which might actually scare anyone into paying higher taxes. But then they’d be in a double bind where a higher sensitivity would put the solar variation back into play as a major driver, even on their own Mickey Mouse figures.


  5. tallbloke says:

    To put some back of the envelope figures on it Willis, if NASA has it right and 26% if the incoming insolation is reflected off by cloudtops and the atmosphere itself, then the 64% emitted by the atmosphere and clouds as IR is around 64% of 74% of 342W/m^2

    That comes out at 162W/m^2

    Gavin da Schmidt famously said the atmosphere re-radiates down as well as up, but why would it re-radiate any more than 162W/m^2 downwards? Where does Trenberth’s 324W/m^2 come from?

    Seems to be out by a factor of two on the high side to me. That’s probably an oversimplification, but ballpark.


  6. Willis Eschenbach says:

    Tallbloke, your claims about the temperature of the moon have several problems. These are best explained by scienceofdoom at his post at


    If you have further questions on what he writes, probably best that you ask them there.

    My best to you,


    PS – the Trenberth graphic does not balance, as you point out. This has been a long-time gripe of mine. I have an updated version of it, which does balance, at:

  7. Willis Eschenbach says:

    My bad, wrong URL, use

  8. tallbloke says:

    The really awkward thing Willis, is not that Trenberth’s imaginary budget doesn’t balance, but empirical observations can’t add it up yet either. The closest the southampton oceanographers got was within 30W/m^2. Your take on Trenberth’s diagram is interesting too, thanks.

    I accept there is an oversimplification in the Moon paper, but nonetheless, the Earth’s energy balance is actually substantially different to both Trenberth’s and NASA’s versions of it. As I proved with my OHC calcs.

    If the Moon paper guys got it wrong, I shall carry on trying to think up other ways to demonstrate it which are irrefutable.

    Best to you too, thanks for the input.


  9. erlhapp says:

    Hi Tallbloke,
    If downward radiation by the atmosphere were to be effective in raising temperature below the point of emission we would see a gradual transition from a strong July maximum in the stratosphere (where ozone is a strong absorber of outgoing radiation that peaks in NH summer due to emission by NH land masses) and an April maximum that exists at the surface in tropical waters (the end of the southern summer that warms the southern ocean). But, the transition is abrupt, the July maximum disappearing in line with diminishing ozone content as one descends below the tropopause.

    So, from observation we see that the posited greenhouse effect does not exist.

    The primary mode of heat loss in the tropics is via simple decompression, the same thing that allows your domestic refrigerator to cool its contents. Where the atmosphere is under compression (subtropical high pressure cells) the heat escapes as long wave radiation while the air warms due to compression. This is a part of the atmosphere where the cloud comes and goes according to the area of these high pressure cells and energy driving them.

    So, a map of the Earth radiation of long wave energy into space will show the most intense radiation over the oceans between 10°south latitude and 30°South latitude.

    The energy turnover in this system of ascending air over the tropical rain forests and descending air over the oceans is the basic dynamic affecting the energy stored in the oceans.

    All the theoretical calculations from Stephan Bolzman’s equations and the like ignores geography. Geography is basic to the nature of the flows of energy and potential for absorption and storage. Its a variable window that opens over the southern oceans.

    The other geographical influence that is important in driving insolation at the ocean surface is the variable proportion absorbed or reflected by the atmosphere. Hence the importance of ice cloud, upper atmosphere temperature, ozone content and the flux in the polar vortex driving stratospheric ozone concentration. The vortex responds to changing atmospheric pressure at the poles vis a vis low latitudes.

    So, in the final analysis both diagrams are simply ‘unhelpful’.

  10. tallbloke says:

    Wow, thanks Erl, and great to have you drop by. It certainly seems the Earth and it’s oceans and atmosphere is too complicated to be treated as a lump of coal in these calcs. I’d like to say something more profound but it’s 3am here and the brain is fading fast so I’ll sign off until tomorrow.


  11. Willis Eschenbach says:

    Thanks, Tallbloke. Do you have a citation for the Southampton oceanographers study?


  12. slimething says:

    I’ve wondered for sometime after reading Willie Soon’s paper why there there is no temperature signature following CO2 domes over cities such as SLC Utah (example given in Soon’s paper).

  13. tallbloke says:

    Willis, I don’t have it to hand since a recent disk crash. It’ll be somewhere on my backup drive. I found the paper by picking through their website and googling a bit.


    If I get around to searching the backup drive for the .pdf, I’ll email you.


    Edit: I tracked down the link I’d posted on another forum:

    Click to access i1520-0442-12-9-2856.pdf

    But, surprise surprise, it is no longer there…
    I did find the addendum to the paper though, if that helps track it down.

    Click to access njch3af_2d.pdf

  14. tallbloke says:

    Willis Eschenbach says:
    June 15, 2010 at 1:11 am (Edit)

    PS – the Trenberth graphic does not balance, as you point out. This has been a long-time gripe of mine. I have an updated version of it, which does balance, at:

    Energy Budget

    Care to tell us what the back radiation and surface radiation figures are based on then Willis? 🙂
    It might balance, but is it based on empirical evidence or somehing else??

  15. Willis Eschenbach says:

    Tallbloke, you say:

    Care to tell us what the back radiation and surface radiation figures are based on then Willis?

    It might balance, but is it based on empirical evidence or somehing else??

    The various figures in the diagram come from various places. The surface radiation is the simplest, as it is based on the temperature of the planet. Back radiation is from a host of measurements of downwelling radiation done around the globe. Latent heat is from an estimate of global evaporation, which in turn is mostly from an average of global precipitation. Sensible heat is a balance calculation. The details of all of this are given in the two Trenberth papers:

    Click to access 10.1175_2008BAMS2634.1.pdf

    Click to access KiehlTrenberth.pdf

    All the best,


    PS – will your site accept links in the comments? I know it won’t accept graphics, but how about links?

  16. tallbloke says:

    Hi Willis,
    So, lots of empirical data, and a model to extrapolate those data into a global figure. But still the 30W/m^2 gap to account for. Plenty of room for my whacky theory about Ocean Heat retention and emission then. 🙂

    thanks for the links to the Trenberth papers.
    Yes, just type the link same as at WUWT and it will be highlighted and active.
    I can’t find a way to enable graphics for users, but if you give the link, I’ll post it for you.

  17. tallbloke says:

    L. C. Schanz1, 2 and P. Schlüssel1, 3
    (1) Meteorologisches Institut, Universität Hamburg, Hamburg, Germany
    (2) Present address: Deutsche Forschungsanstalt für Luft und Raumfahrt, D-51140 Köln, Germany
    (3) Present address: Meteorologisches Institut, Universität München, Theresienstrasse 37, D-80333 München, Germany

    Received: 3 June 1996 Revised: 16 December 1996
    Summary The back radiation has been measured with an Eppley pyrgeometer on board the R/V Vickers in the tropical Pacific Ocean during the field campaigns COARE (Coupled Ocean Atmosphere Response Experiment) and CEPEX (Central Equatorial Pacific Experiment) in February and March 1993, respectively. As part of these compaigns radiosondes have been launched from the Vickers several times per day and cloud cover was observed frequently. The radiosonde and cloud observations are used together with a radiative transfer model to calculate the back radiation for a subsequent intercomparison with the pyrgeometer measurements. Another means of comparison is derived from space-borne SSM/I (Special Sensor Microwave/Imager) measurements. The mean difference between pyrgeometer measurements and simulated downwelling irradiance at the sea surface is less than 2 W/m2, at a mean of 425 W/m2 in the warm pool, with a standard deviation of 8 W/m2. The comparison of satellite measurements with pyrgeometer readings shows a mean difference of-3 W/m2 and a standard deviation of 14 W/m2. The mean difference between satellite-derived back radiation and simulated one is 3 W/m2 with a standard deviation of 14 W/m2. Comparisons with results obtained from bulk formulae applied to surface meteorological observations show a good performance of the bulk parameterisations in the cloud-free case but a general overestimation of the back radiation in cloudy situations.

  18. tallbloke says:

    Estimating surface radiation ¯ uxes in the Arctic from TOVS
    brightness temperatures
    Applied Physics Laboratory, Polar Science Center, University of Washington,
    Seattle, Washington 98195, U.S.A.
    J. R. KEY
    Department of Geography, Boston University, 147 Bay State Road, Boston,
    Massachusetts 02215, U.S.A.
    (Received 25 January 1996; in ® nal form 20 June 1996 )
    Abstract. A new method for estimating downwelling shortwave and longwave
    radiation ¯ uxes in the Arctic from TOVS brightness temperatures has been
    developed. The method employs a neural network to bypass computationally
    intensive inverse and forward radiative transfer calculations. Results from two
    drifting ice camps (CEAREX, LeadEx) and from one coastal station show that
    downwelling ¯ uxes can be estimated with r.m.s. errors of 20WmÕ 2 for longwave
    radiation and 35WmÕ 2 for shortwave radiation. Mean errors are less than
    4WmÕ 2 and are well within the bounds required for many climate process studies.

    Results – 160-240W/m^2

  19. Buffoon says:

    Back-radiation has no portion reflected?

  20. tallbloke says:

    Good question. Willis?

  21. Willis Eschenbach says:

    Buffoon says:
    June 16, 2010 at 3:20 pm

    Back-radiation has no portion reflected?

    Typical IR absorption/emission for the earths surface in on the order of 98% for almost all surfaces. See here for details. As a result, for simple budgets like the Trenberth budget, it is usually treated as a black body.


  22. Agile Aspect says:

    >Buffoon says:
    >Back-radiation has no portion reflected?

    The so-called back-radiation is 3 dimensional so the emission of the photon (which is vector with magnitude and direction) can be in any direction – all directions are equally probably for a molecule which vibrating. If you time average these vectors over a sphere for a period of time which much longer than the rotational rate of the molecule, the net results is zero.

    If the photon of interests collides with the other 99.996 % of the molecules in the troposphere and is not absorbed, then it scatters and it’s frequency is shifted to longer wavelength. The molecule involved in the collision picks up kinetic energy.

    When you’re talking about molecules and their interaction with electromagnetic radiation, then you’re in the quantum regime and the electromagnetic field is modeled as a particle and not a wave.

  23. Juraj V. says:

    Hi tallbloke,

    if the back radiation is nonstop beaming 321 W/m2 on me, by covering my face against the cloudy or night sky, it would freeze instantly?

    I think that the fact we are kept warm by warm air (which absorbed energy from the surface, which absorbed the sun energy) and this simple warming effect of heat stored in air (oceans) is totally wrongly misinterpreted as being caused by back radiation.

  24. Willis Eschenbach says:

    Juraj V. says:
    June 30, 2010 at 4:11 pm

    Hi tallbloke,

    if the back radiation is nonstop beaming 321 W/m2 on me, by covering my face against the cloudy or night sky, it would freeze instantly?

    This is the most common misconception about downwelling radiation. Suppose you put a sheet of steel between you and the night sky. Will your face freeze? No. In fact, it will feel slightly warmer.

    The reason is that you have replaced the night sky (radiating at 321 W/m2) with a piece of steel (radiating at 390 W/m2). So the net radiation doesn’t drop to zero as you might assume. Instead, it increases slightly …


  25. tallbloke says:

    Willis, I was thinking about increasing temps and reduced cloud cover earlier. Some folk say you should get more cloud as temperature increases because of increased evaporation. But this isn’t what happened during the 1980-1998 period. According to the ISCCP data, cloud cover was reduced. I think I have an answer to that.

    The very active sun during the period warmed the ocean more and if Svensmark is right, there would have been less cloud nucleation due to lowered GCR counts. But why didn’t increased SST cause more evaporation and replace the missing cloud? Here’s my answer:

    The reduced cloud cover means there was less back radiation to cause evaporation from the ocean surface, and this more than offset the increase in evaporation due to raised SST’s.

    Make sense?

  26. P.G. Sharrow says:

    Tallbloke; I think you need to add cooling or cold atmosphere to your cloud creation.
    A warming atmosphere would have less clouds.
    In our present conditions we have a cooling atmosphere over a warm ocean, = more clouds and presipiation, therefor continued cooling of both ocean and atmosphere. As the sun sleeps and the solar wind is low, the atmosphere cools. When the sun awakes and the wind increases the atmosphere will warm, the clouds clear and the now cool ocean will warm.
    The solar wind sets the “Goldilocks zone” that the Earth travels in. Low wind, cold Earth. High wind, warm Earth.
    As Lief would sat the TSI has nothing to do with the climate, it’s blowing in the wind pg

  27. tallbloke says:

    PG, nice one.

    How many times can a man turn his head,
    and pretend that he just doesn’t see?

    The answer, my friend, is blowing in the wind
    The answer is blowing in the wind

    Play it again Bob, and again, and again.

  28. DirkH says:

    Hi tallbloke, nice post.
    One minor quibble. Stefan and Boltzmann are two different people,

    “The law was deduced by Jožef Stefan (1835-1893) in 1879 on the basis of experimental measurements made by John Tyndall and was derived from theoretical considerations, using thermodynamics, by Ludwig Boltzmann (1844-1906) in 1884.”


  29. tallbloke says:

    Heh, thanks Dirk H. My mental lapses are worsening it seems. Oh well, you gotta go with what you got.

  30. P.G. Sharrow says:

    “Old Timers” diease ;-]

  31. tallbloke says:

    Heh, partly that no doubt, but mostly the after effects of getting punted into the upper branches of a roadside tree by a lunatic in a 4×4. See ‘about me’ page.

  32. […] Posted: November 16, 2010 by tallbloke in solar system dynamics 0 A while ago I posted a tongue in cheek thread about the old Keihl and Trenberth Earth energy budget diagram and the new shiny all colour one NASA […]

  33. KAP says:

    You ask, “What happened to ‘Back Radiation from the atmosphere’??” but it is clear that the first diagram was only intended to track the solar radiation part of the budget, rather than the whole budget. The 390 W/m^2 comes from basic thermodynamics (Earth’s mean temp of 288 K implies a TOTAL mean radiation of 390) which is the part of the budget omitted from diagram 1. Since the incoming 168 is reduced by convection and evapotranspiration to 66, the downwelling total must be 390-66=324 to balance.

  34. John Satterfield says:

    Cause and effect. The sun heats the earth and atmosphere. The highest temperature is at the surface of the earth. The cold atmosphere cannot heat the earth. dah! the heat in the atmosphere must therefore radiate into space at night.