Methane: The Irrelevant Greenhouse Gas

Water vapor has already absorbed the very same infrared radiation that Methane might have absorbed.

Guest essay by Dr. Tom Sheahen

Q: I read that methane is an even worse greenhouse gas than carbon dioxide, and cattle are a big source of methane emissions. How are they going to regulate that? Not just cattle, but dairy cows as well! That doubles the worry.

Fortunately, there is really nothing to worry about, scientifically. The main thing to worry about is over-reacting politicians and another layer of unnecessary government regulations.  

To understand methane’s role in the atmosphere, first it’s necessary to understand what absorption means. When light passes through a gas (sunlight through air, for example), some molecules in the gas might absorb a photon of light and jump up to an excited state. Every molecule is capable of absorbing some particular wavelengths of light, and no molecule absorbs all the light that comes along. This holds true across the entire electromagnetic spectrum – microwave, infrared, visible, and ultraviolet.

The process of absorption has been studied in great detail. In a laboratory set-up, a long tube is filled with a particular gas, and then a standard light is set up at one end; at the other end of the tube is a spectrometer, which measures how much light of each wavelength makes it through the tube without being absorbed. (Mirrors are placed so as to bounce the light back and forth several times, making the effective travel path much longer; this improves the precision of the data.) From such measurements, the probability of radiation being captured by a molecule is determined as a function of wavelength; the numerical expression of that is termed the absorption cross-section.

If you carried out such an experiment using ordinary air, you’d wind up with a mixture of results, since air is a mixture of various gases. It’s better to measure one pure gas at a time. After two centuries of careful laboratory measurements, we know which molecules can absorb which wavelengths of light, and how likely they are to do so.

All that data is contained in charts and tables of cross-sections. Formerly that meant a trip to the library, but nowadays it’s routinely downloaded from the internet. Once all the cross-sections are known, they can be put into a computer program and the total absorption by any gas mixture (real or imaginary) can be calculated.

The many different molecules absorb in different wavelength regions, known as bands. The principal components of air, nitrogen and oxygen, absorb mainly ultraviolet light. Nothing absorbs in the visible wavelength range, but there are several gases that have absorption bands in the infrared region. These are collectively known as the GreenHouse Gases (GHG), because absorbing infrared energy warms up the air – given the name greenhouse effect.

The adjacent figure shows how six different gases absorb radiation across the infrared range of wavelengths, from 1 to 16 microns (mm). The vertical scale is upside-down: 100% absorption is low, and 0% absorption (i.e., transparency) is high.

methane_absorption_spectra

It’s important to realize that these are shown on a “per molecule” basis. Because water vapor (bottom bar of the figure) is much more plentiful in the atmosphere than any of the others, H­2O absorbs vastly more energy and is by far the most important greenhouse gas. On any given day, H2O is a percent or two of the atmosphere; we call that humidity.

The second most important greenhouse gas is carbon dioxide (CO2), which (on a per-molecule basis) is six times as effective an absorber as H2O. However, CO2 is only about 0.04% of the atmosphere (400 parts per million), so it’s much less important than water vapor.

Now it’s necessary to scrutinize the figure very carefully. Looking across the wavelength scale at the bottom, H2O absorbs strongly in the 3-micron region, and again between 5 and 7 microns; then it absorbs to some degree beyond about 12 microns. CO2 has absorption bands centered around 2.5 microns, 4.3 microns, and has a broad band out beyond 13 microns. Consequently, CO2 adds a small contribution to the greenhouse effect. Notice that sometimes CO2 bands overlap with H2O bands, and with vastly more H2O present, CO2 doesn’t matter in those bands.

Looking at the second graph in the figure, methane (CH4) has narrow absorption bands at 3.3 microns and 7.5 microns (the red lines). CH4 is 20 times more effective an absorber than CO2in those bands. However, CH4 is only 0.00017% (1.7 parts per million) of the atmosphere. Moreover, both of its bands occur at wavelengths where H2O is already absorbing substantially. Hence, any radiation that CH4 might absorb has already been absorbed by H2O. The ratio of the percentages of water to methane is such that the effects of CH4 are completely masked by H2O. The amount of CH4 must increase 100-fold to make it comparable to H2O.

Because of that, methane is irrelevant as a greenhouse gas. The high per-molecule absorption cross section of CH4 makes no difference at all in our real atmosphere.

Unfortunately, this numerical reality is overlooked by most people. There is a lot of misinformation floating around, causing needless worry. The tiny increases in methane associated with cows may elicit a few giggles, but it absolutely cannot be the basis for sane regulations or national policy.

 

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253 Responses to Methane: The Irrelevant Greenhouse Gas

  1. The mega methane mania finds its roots in the Greenland ice cores where it was observed that large fluctuations of methane coincided with fluctuation in stable hydrogen and Oxygen isotopes (erroneously considered a paleothermometer). Especially around the erroneously considered cold Younger Dryas. To the cherry pickers it looked like the methane spikes had caused sudden large temperature swings, like the ‘more-than-ten-degree-within-a-decade’stuff of Richard Alley and friends.

    However this could have been challeneged immediately comparing the Greenland ice core records with Antartica, nothing adds up considering global temperatures. The Antarctic CO2 record has no corrolation with the Greenland isotope ‘temperatures’ while the Greenland CH4 records don’t compare with the Antarctic isotope ‘temperatures’. So something had to be wrong there. But that methane would have nothing to do with global temperature is obviously a too unconvenient truth to alarmists.

  2. Bloke down the pub says:

    Thank you for that. It neatly describes one of the most important issues to be remembered when discussing problems with cagw theory.

  3. Ex-expat Colin says:

    Amazing really when the end game is considered. Kill off all the big time f*rters – meat and milk disappears. Eat cats, dogs, birds…ok for China/Europe? So we get veggie with leaves and stuff that needs CO2 for growth…oh no, thats gone as well.

    Good article…thanks

  4. johnmarshall says:

    CH4 does have a negative effect on the atmosphere in that its breakdown by chemical reactions in the atmosphere use a lot of oxygen. Thankfully the CO2 and H2O products are used by plants to produce O2. So a neat closed circuit. Cow farts are actually good for the planet.
    The term ”Greenhouse Gas” is a misnomer since the action of gasses in the atmosphere in no way acts like a greenhouse. Greenhouses get warm because they stop convection of the hot air inside. The atmosphere has no lid so convection is free to act.

  5. MikeUK says:

    Great article, the key to the whole CAGW scam I believe.

    CO2 and possibly methane could have a played a major role in getting Earth out of ice ages and snowball Earth conditions, i.e. when there was much less water vapour in the atmosphere. But once the Earth is warm and humid (as it is now) water vapour dominates.

    Water vapour even dominates the “consensus” CAGW scare, supposedly doubling CO2 causes a small rise in temperature, which then causes more water vapour, which is the thing that dominates the eventual rise (allegedly).

  6. Steve Maley says:

    Reblogged this on Maley's Energy Blog and commented:
    A concise and thoroughly understandable explanation of the greenhouse effect, and why a little methane in the mix is irrelevant.

  7. TRG says:

    Why haven’t I heard about this before?

  8. Christy Herschel says:

    I have an ongoing conversation with a friend who’s always trying to convince me of AGW. Recently he emailed this link with regard to CO2 causing warming:
    “Permafrost thawing could accelerate global warming, researchers say
    Science Recorder – ‎40 minutes ago‎
    On Monday (April 7), researchers from Florida State University announced that they have discovered new evidence that permafrost thawing is releasing copious amounts of greenhouse gases into the atmosphere by way of plants.”

    In my research I was looking for articles referencing why the permafrost is melting. Would your article be sufficient to convince that even with melting permafrost, the effect is negligible?

  9. Somebody says:

    “The second most important greenhouse gas is carbon dioxide (CO2), which (on a per-molecule basis) is six times as effective an absorber as H2O” – H2O is polar. CO2 is not, so it has non radiative modes. H2O is non linear. CO2 is linear, more symmetric (meaning: degenerate modes). For those reasons, the CO2 infrared spectrum is not so rich as the H2O spectrum.

  10. kramer says:

    Wouldn’t methane be a factor in dry climates?

  11. philjourdan says:

    The tiny increases in methane associated with cows may elicit a few giggles, but it absolutely cannot be the basis for sane regulations or national policy.

    And if sane people ran the governments, it would not be an issue. However, given past actions, the sanity of government officials is always in question.

  12. Long John says:

    Harken to me! The day will come when a man will be burned at the stake for daring to eat a can of baked beans.

  13. Patrick says:

    “Somebody says:

    April 11, 2014 at 4:44 am”

    Exactly! I was talking to a colleague at work today and I asked what his opinion was with regards to CO2 concentration in air, assuming well mixed etc. He said about 50%. Jaw dropping! So I pointed out that in, well mixed air, ~78% is N2, ~21% is O2 and CO2 is ~.03%. Stunned looks abound on his part!

  14. Brad says:

    Wait, but the H20 also absorbs bands which overlap CO2. And the absorption of Methane is much greater in it’s bands than H20. This doesn’t explicitly discount anything in the article, but there are more complex interactions than just the one listed here.

  15. Steve Maley says:

    Excellent post! I’ve been blogging about AGW for 10 years, but haven’t really had a grasp on the mechanism until reading this article.

  16. Patrick says:

    Termites and healthy forests are the biggest source of CH4 on this rock. I recall “debates” in the past where methane (CH4) is discussed. One commenter said, and I quote “CH4 has for carbons”…I kid you not!

  17. Mike Maguire says:

    Excellent, easy to understand article discussing this important realm.

  18. Andy Hirst says:

    Excellent post. Just a couple of (simplistic) comments:
    1. The energy of electromagnetic photons is related to their frequency (E = h x f), and inversely to the wavelength. If you get an absorption diagram similar to the one in the article, but with photon energy on the x-axis, you can see that water is THE massive ‘greenhouse gas’, and that the contribution of CO2 energy absorption is small in comparison.
    2. The water vapour content of the atmosphere varies widely, usually between 0.5% and 5% in the lower atmosphere (NB. anything over 3.5% tends to mean it is raining heavily). Combustion systems I work on are noticeably more ‘sluggish’ to react on rainy days . This variation absolutely dwarfs the effect of the miniscule increase in CO2 content.

  19. Gary Pearse says:

    Tom, this is one of those posts where I receive a quantum addition to my education on this subject. Also, the presentation of it is understandable to every reader, regardless of background education and experience. Thanks. I was wondering if your graph above could be made more effective (or probably better make a second graph) by changing the ordinates from simple unit absorption to quantitative units that take the abundance of the gases in the atmosphere into consideration? This would be a more powerful illustration of your very thorough explanation. I hope some of the CO2 worriers join this discussion – Mosher for example, to argue their case. I have no doubt they understand the details of this subject.

  20. ‘Water vapor has already absorbed the very same infrared radiation that Methane might have absorbed’

    On that basis, seen as this is not an effective part of the spectrum as CO2 the most effective GHG is still co2!

    Water vapour and co2 as GHGs and heat vent blockers. [Therefore resulting in AGW!].

    ‘70 years ago the view that co2 could affect the global climate was held by only a tiny minority of climate scientists, many assumed there would be a self regulating mechanism that would put things back into balance. Then there was the scientifically valid view that water vapour also trapped radiation and warms up the Earth and it is more abundant in the atmosphere than co2. But research in the 1940s changed all that, Guy Stewart Callender, a British engineer showed that radiation absorption is not even. Water vapour absorbs is mainly in the 18-30 micro-meter band and allows most of the rest to escape into space, in effect these absorption gaps act like cooling vents , but co2 absorbs in a different range, 8-18 micro-metre so Callender concluded that co2 mops up this escaping radiation, effectively acting as a plug to these cooling vents’.

    As you can see here!

  21. MikeB says:

    TRG says:
    April 11, 2014 at 4:40 am

    Why have I not heard about this before?

    Because it’s wrong.
    Indeed, it would be truly amazing if everyone in the world hadn’t realised this except Tom Sheahen.

    First it would be helpful to describe the graph as ‘transmission’ instead of ‘absorption’, since that is what is shown. It should also state the path length over which these transmission figures have been assessed. ‘A per molecule basis’ is very dubious ( it looks more like total transmission from ground to space). What is the provenance of this graph?

    The failure here is that although CO2 is a very small proportion of the atmosphere, there is no sightline through the full thickness of the atmosphere which will not intersect a CO2 molecule in a very short distance. For example, 95% of radiation at 15 micron will be absorbed within a distance of 1 metre. The atmosphere is therefore opaque to radiation at 15 microns, due to the small amount of CO2 present. Water vapour (if present) also absorbs at 15 microns but not at the 100% level of CO2.
    Similarly for methane. In addition, the only reason that methane is considered to be more potent than CO2 is because there is so little of it. Its absorption bands are not saturated and its affects are therefore linear and not logarithmic.

  22. Joe Born says:

    Very well-written–and, I’m embarrassed to say, informative; I had not previously reflected on the methane claims being bruited about.

  23. DirkH says:

    “The main thing to worry about is over-reacting politicians and another layer of unnecessary government regulations. ”

    Might soon come to a point where it becomes necessary to leave the West as it strangulates itself under unnecessary self-imposed shackles; and wait it out til the parasites have died off.

  24. DirkH says:

    MikeB says:
    April 11, 2014 at 5:15 am
    “Water vapour (if present) also absorbs at 15 microns but not at the 100% level of CO2.”

    So CO2 manages to saturate its absorption lines while water vapor doesn’t? Tell us more about it, Mike! Hint – you mentioned mean free path length yourself. Think about what that means…

  25. Alan Robertson says:

    Ex-expat Colin says:
    April 11, 2014 at 4:31 am

    “Amazing really when the end game is considered.”
    _______________
    Yes.
    What we’ve seen from those people certainly fits with “the end game” which has been discussed here. What’s the end game? There is an idea, widely promoted from within certain circles, that too many human beings exist and that steps must be taken to reduce human populations. The people promoting that idea are the same people promoting the idea of man made global warming. When you are confronted by one of those idealogues, or their useful idiot followers, recommending a high building to put their beliefs into practice has no effect, as it is you that they envision being reduced, not themselves.

  26. Joe Born says:

    Something that may help readers assess the criticisms that this post will inevitably attract is to provide tables of absorption (in percent/meter per mole/liter?) as a function of wavelength for the three compounds of interest.

  27. Chuck L says:

    My understanding is that its residence in the atmosphere is relatively short and the methane clathrates found in Arctic that alarmists claim will melt are more stable and less likely to melt/be affected by warming than previously believed. There were a few papers that came out in the last year or so on this topic. I hadn’t known about the comparative absorption spectra so unless there is a mechanism that will increase methane by 10,000% no reason to worry about CH4

  28. Somebody says:

    By the way, that chart might be misleading. The water spectrum certainly does not end where that line ends in the chart :)
    [img]http://upload.wikimedia.org/wikipedia/commons/9/97/Water_infrared_absorption_coefficient_large.gif[/img]

  29. Coldlynx says:

    And the other side of the coin is that all green house gases also emits energy in the same wavelength bands.

  30. resistance says:

    Since when is sanity a pre-requisite for government regulations? lol

  31. swood100 says:

    kramer says:
    April 11, 2014 at 4:45 am
    Wouldn’t methane be a factor in dry climates?

    Furthermore, does any amount of water in the atmosphere negate the effect of any amount of methane in the atmosphere?

  32. Gary Pearse says:

    Chuck L says:
    April 11, 2014 at 5:32 am

    “My understanding is that its residence in the atmosphere is relatively short and the methane clathrates found in Arctic..”

    They are found in more than the arctic – along continental margins all over the world – off the coast of southern British Columbia and the Bermuda triangle are a couple of examples.

    http://geology.com/articles/methane-hydrates/

    Scroll down for map.

  33. Leonard Weinstein says:

    I agree that methane is a small player, but not for the reasons you stated. The first thing you need to understand is that gases that nearly saturate absorption in a short distance result in the last absorption and emission (to space) to occur at very high altitude. It is the effective average altitude of emission to space that sets the energy balance and thus temperature at that (average) effective altitude, and also via the lapse rate, govern the greenhouse effect. However, as the atmosphere cools with increasing altitude (from the lapse rate), almost all of the water vapor condenses out, first as clouds at moderate altitudes, and most of the remainder as ice crystals at higher altitudes. The CO2 and methane are not condensed out at the temperatures encountered. Thus the relative fraction of water vapor to CO2 and methane decreases sharply as you approach the TOA, where the action is very important. This is the reason that CO2 and methane have a very large effect at small concentrations. However, due to their small concentrations, the effect is not totally dominate.

  34. resistance says:

    OT:
    I’m flying over the upper-Midwest right now, and it looks like it could be mid-January out there!

  35. blackdog says:

    Perhaps I’m blind or simply not seeing things correctly, but at 7.5 microns water only seems to absorb about 40% leaving plenty of room for CH4 to absorb at that wavelength.

  36. Matthew W says:

    Once again, actual science defeats alarmist propaganda !!

  37. stevefitzpatrick says:

    Tom,
    I think it not very useful to look at the entire atmosphere when you consider the relative importance of different GHG’s. It it true that water vapor dominates near the surface, especially in temperate and tropical regions. But far more important when considering heat loss to space is the composition of the atmosphere from the upper troposphere to space, where relative water vapor concentration is many times lower than near the surface. It is completely true that adding a bit of methane will not significantly change atmospheric absorption at low altitudes because of the dominance of water vapor (except in the polar winter), but methane is well mixed in the atmosphere, and its absorption does make a difference in heat loss from the upper troposphere to space. Increasing atmospheric methane for sure reduces net heat loss to space. The concentration of methane in the atmosphere has not been rising very much (IPCC projections for methane were completely wrong!), and methane’s contribution to total GHG warming is not increasing very much….. so it really does not appear to be much of a cause for worry, but not because it does not act as a GHG; it does.

  38. Coach Springer says:

    I think of the history of the world and vast herds of grass eating animals and I can’t help but snicker at people scared by cow farts.

  39. DirkH says:

    Leonard Weinstein says:
    April 11, 2014 at 5:58 am
    “However, as the atmosphere cools with increasing altitude (from the lapse rate), almost all of the water vapor condenses out, first as clouds at moderate altitudes, and most of the remainder as ice crystals at higher altitudes. The CO2 and methane are not condensed out at the temperatures encountered. ”

    Well, and what does water vapor do when it condenses? It forms tiny little blackbodies in the sky…
    …which absorb what they don’t reflect with a Planck spectrum at their frigid temperatures… Icehouse effect not greenhouse effect… warm yourself up with the cosy IR blackbody radiation from a bunch of mineral water bottles right out of your fridge. Much warmer than absolute zero!

  40. ferd berple says:

    The atmosphere is therefore opaque to radiation at 15 microns, due to the small amount of CO2 present. Water vapour (if present) also absorbs at 15 microns but not at the 100% level of CO2.
    ————–
    if CO2 is already absorbing at the 100% level, adding more Co2 cannot have any effect whatsoever. Or are we to believe that doubling CO2 will result in 200% absorption?

  41. DirkH says:

    swood100 says:
    April 11, 2014 at 5:54 am
    “Furthermore, does any amount of water in the atmosphere negate the effect of any amount of methane in the atmosphere?”

    The right word is “cannibalization”. When two gases compete for the same photon only one of them can get it. It doesn’t “negate” the effect, it neutralizes it, obviously.

  42. Greg says:

    MikeB What is the provenance of this graph?

    Similarly for methane. In addition, the only reason that methane is considered to be more potent than CO2 is because there is so little of it. Its absorption bands are not saturated and its affects are therefore linear and not logarithmic.

    ===

    And what is the provenance of your information?

    What’s the free path of a photon at the 3.5 and 7.3 micron bands? And what’s the probability of it meeting an H20 before a CH4 molecule?

  43. DirkH says:

    ferd berple says:
    April 11, 2014 at 6:13 am
    “if CO2 is already absorbing at the 100% level, adding more Co2 cannot have any effect whatsoever. Or are we to believe that doubling CO2 will result in 200% absorption?”

    Enhanced GHE comes about through pressure broadening; only the frequencies at the edges of the band which are NOT saturated can become more saturated.

  44. Jerker Andersson says:

    “Notice that sometimes CO2 bands overlap with H2O bands, and with vastly more H2O present, CO2 doesn’t matter in those bands.”

    Even though the absorbtion bands for CO2 and H2O overlaps at som frequencies there must be some regional effects from higher CO2. For example dry air over large deserts or central Antarctica. Is’nt the ammount of water vapour there at times so low that the CO2 actually matters in bands that overlap?

  45. ferdberple says:

    However, as the atmosphere cools with increasing altitude (from the lapse rate)
    ———————–
    GHG cools the atmosphere – otherwise it would be isothermal due to conduction. The lapse rate (DALR) is due to gravity and convection, limiting the cooling. Condensing water during convection reduces the actual lapse rate to less than the DALR.

  46. Col Mosby says:

    EArlier was an article that calculated the percentage of methane released from the permafrost
    that actually made it to the atmosphere. It was very small, almost trivial.

  47. ferdberple says:

    Increasing atmospheric methane for sure reduces net heat loss to space.
    =============
    don’t be so sure. methane absorbs energy from the surrounding air and radiates this to space. otherwise the atmosphere would be warmer than it is (since O2 and N2 do not radiate).

    GHG cannot reduce the net heat loss to space because energy in and energy out must be equal when the earth is in equilibrium.

  48. RCM says:

    You will hear more and more about the evils of methane…..I promise. It is going to be the new Devil against which all good citizens must fight. There are a couple reasons:

    1. The anti- CO2 campaign has pretty well run its course. People are beginning to get wise to the scam. Fighting CO2 came about because the anti-pollution campaign was pretty well at an end. However, the organizations who had fought that battle were not ready to close shop and go home; they needed a new enemy to battle. No organization ever willingly dies. There are jobs at stake. (This shifting of a crusade to a new cause to keep the army alive is common -I give you the continuing existence “The March of Dimes” an organization instituted to fight Polio…which was defeated more than 50 years ago.) The idea of attacking CO2 was ingenious – a pollutant to fight which can never be defeated, unlike noxious chemicals. Every breath you take feeds the demon!
    The organization need never worry about going under again they thought….except the damned climate wouldn’t cooperate. So… A new enemy.

    2. The other and more important reason for the growing attacks on methane is because of the discovery of practical means (only in testing so far) of extracting Methane Hydrate. This worries the Greens because “…methane hydrate deposits are believed to be a larger hydrocarbon resource than all of the world’s oil, natural gas and coal resources combined.” Further, the stuff is -everywhere-.
    http://geology.com/articles/methane-hydrates/

    Unless a good reason to stop its development, in 50 years cheap hydro-carbon energy is going to be bountiful…….

    Why the new urgency in the campaign?
    Here’s a link that says that Japan hopes to commercialize methane hydrate “within 10 years”.

    http://www.platts.com/latest-news/natural-gas/tokyo/platts-feature-japan-makes-big-strides-in-methane-27779018

  49. ferdberple says:

    the percentage of methane released from the permafrost that actually made it to the atmosphere. It was very small, almost trivial.
    ============
    methane is an energy source. Life rapidly converts it to CO2 and H2O when oxygen is present. which is why there is very little methane in the atmosphere. long ago bacteria learned how to turn methane into food.

    methane is produced in huge quantities within the earth due to plate tectonics. fossilized CO2 (limestone) along with water is reduced by iron and heat within the earth to form methane. this bubbles up through the oceans to the surface. occasionally it is trapped beneath structures in the earth, where it can be harvested economically to run human industry.

  50. CaligulaJones says:

    ” Kill off all the big time f*rters”

    Well, I think what the Earth Firster-types have in mind is killing off the DOMESTIC f*rters.

    That they will be replaced by NATURAL f*rters such as similar-sized herds of bison, for instance, is one of those “logic gaps” that doesn’t fit in with the emotion of hugging a tree.

  51. ferdberple says:

    methane is produced in huge quantities within the earth due to plate tectonics. fossilized CO2 (limestone) along with water is reduced by iron and heat within the earth to form methane.
    ===========
    in this regard, methane is a fossil fuel. however, it is not made from dinosaurs. it is made from limestone, which is the fossilized remains of CO2.

  52. Bruce Cobb says:

    For Warmenistas, the question isn’t relevance but rather usefulness in selling their product, Alarmism. Methane is useful as a red herring distraction, taking some of the heat off CO2, and also in amping up the “guilt” factor, since we humans (supposedly) produce via our “human activities” some 60% of the methane. Now, they’ve even ramped up methane’s GWP (global warming potential), measured over a 100-year timespan, formerly estimated to be 21 to now thought to be 34 times what CO2’s is. So, it’s even worse than we thought, of course. It’s amazing, with all that “extra” warming power, though, how little effect it actually has on climate. I guess without man’s influence, we should now be back to ice age conditions, by their calculations.

  53. arthur4563 says:

    MikeB claims that an opaqueness exists at certain wavebands due to the presence of CO2.
    Apparently adding CO2 will make no difference at current levels, although simple logic would indicate that reducing it will make a difference, at some point. And what about absorption levels?
    More clarity needed for this post, along with some references.

  54. arthur4563 says:

    I’ve decided that global wamists are climate chauvinists and a bunch of Dr Panglosses, all believing that this climate is the best of all possible climates, despite having only experienced
    this one.

  55. swood100 says:

    DirkH says:
    April 11, 2014 at 6:15 am
    The right word is “cannibalization”. When two gases compete for the same photon only one of them can get it. It doesn’t “negate” the effect, it neutralizes it, obviously.

    ne·gate
    to nullify or cause to be ineffective: Progress on the study has been negated by the lack of funds.

    But the real question is whether any amount of water in the atmosphere will negate the effect of any amount of methane in the atmosphere. Some have suggested that this is happening at an altitude which contains little H2O. Is the absorption at a lower level not important?

  56. Col Mosby says:

    What’s next, if history is any guide, is some revolutionary new theory that shows methane
    to be absolutely essential for life on Earth, and needs to be maintained at a certain critical minimum level. Oh, wait, I’m confusing methane with that other GHG, whose name I can never remember. Oh yes – it’s carbon dioxide. Does anyone worry that the warmist crowd might actually succeed in drastically reducing CO2 levels?

  57. DirkH says:

    swood100 says:
    April 11, 2014 at 6:58 am
    “Some have suggested that this is happening at an altitude which contains little H2O. Is the absorption at a lower level not important?”

    The level is not important, the mean free path length for a given frequency is. Whether a photon is intercepted 1 time or a thousand times on its absorption-reemission-voyage through the atmosphere does not matter. One absorption-re-emission changes its direction arbitrarily and suffices. If the mean free path length is on the order of the thickness of the atmosphere it escapes directly to space; otherwise it becomes part of the “greenhouse effect”.

    (Ignoring the tiny blackbodies in the sky here)

  58. DirkH says:

    Col Mosby says:
    April 11, 2014 at 7:02 am
    “What’s next, if history is any guide, is some revolutionary new theory that shows methane
    to be absolutely essential for life on Earth, and needs to be maintained at a certain critical minimum level. ”

    http://en.wikipedia.org/wiki/Methanotroph

    BTW, Methane is not oxidized, so it naturally tends to undergo chemical reactions in an oxygen atmosphere. (UV, radicals, VOCs, Ozone) Will never become significant.

  59. AlanG says:

    The last I heard was that methane is broken down in the atmosphere within 10 years

  60. Scorp1us says:

    I also thought that methane is broken down in the upper atmosphere due to ultraviolet light? This then means that methane is not durable, unlike water vapor and CO2, which are both very durable molecules in the atmosphere. If we were to cease methane emissions, methane would eventually drop to zero. Whereas co2 and h20 will remain forever (ignoring biological processes)

  61. Jeff Id says:

    This article is inaccurate. The net temperature rise is about the delay in release of energy from the lower atmosphere to space. Energy absorbed by water is released by water, often at the same wavelengths it absorbs. More CH4, increases the delay in that energy reaching space, trapping heat and increasing the warming effect.

    None of my argument means that CH4 IS relevant, just that the article doesn’t support the conclusion. It is simply not correct to say water has already absorbed that wavelength so CH4 is irrelevant.

  62. Abel Garcia says:

    Remember people can’t be far behind!

  63. Alan McIntire says:

    blackadderthe4th says:
    April 11, 2014 at 5:11 am
    “…70 years ago the view that co2 could affect the global climate was held by only a tiny minority of climate scientists, many assumed there would be a self regulating mechanism that would put things back into balance.”

    There IS such a mechanism. Rainwater removes CO2 from the atmosphere and puts it in the crust, and volcanic action releases CO2 from the crust and puts it back in the atmosphere. When there’s more CO2 in the atmosphere, it’s a little warmer, we get more evaporation of water and more rain to remove CO2 from the atmosphere at a greater rate.

  64. Steve Keohane says:

    I haven’t seen it brought up here, but it seems to me that an intercepted IR photon at a particular wavelength, when absorbed and re-emitted, is re-emitted at a lower energy state, ie. a different wavelength than when first intercepted. The magically infinite emission, absorption and re-emission does not exist as the photon loses energy each interaction.

  65. george e. smith says:

    Well expect a small nuclear explosion from Phil pretty soon.

    While I tend to discount the threat of CH4, as overblown (it’s another nice fuel we can use) the picture is not as simple as Tom depicts.

    But for starters, look at that CH4 band at 3.3 microns; also the CO2 band at 4.xx microns.

    Those we can discard completely, as no threat; in fact they are beneficial from a MMGWCCC point of view, because the only source of any 4 micron or less radiation, is the sun itself, and any atmospheric absorption of sunlight is a global cooling effect.

    But back to that 7.7 or so micron CH4 band overlaid by H2O.

    Well Tom’s graphs are very low resolution transmission spectra, and those “bands” are actually groups of very many much narrower spectral “lines” and there is no assurance that some water line overlaps some methane line, so the fact that the bands overlap, is no assurance that the individual lines do.

    The single molecule lines are in fact quite narrow, being resonances of a very precise structure. Those are then broadened as a result of inter-molecular collisions, giving Temperature broadening due to the Doppler effect, and the motion of the absorbing molecule; and also pressure broadening (actually density) due to the numbers of collisions.

    Even so, the broadened lines at the modest atmospheric T&P are still quite narrow, and line overlaps are not going to be as Tom’s band transmissions assert.

    But Phil, can do the honors. That ozone band at 9.6 microns is actually right in the middle of the so-called atmospheric window, so I’m not sure Tom’s water bands are correctly depicted.

    Water is a great LWIR absorber though.

  66. george e. smith says:

    I should have added what I see others have; it’s a catch and release process , and the more molecules fishing in the pond of photons, the more catches (and cool down delays) there will be.

    But I still think methane is overblown.

  67. JudyW says:

    The oxygen that methane combines with to form CO2 and H2O is ozone. The concern with methane is not it’s GHG properties but the ozone depletion aspect. This goes back to the scare before Global Warming of “We’re all going to die of skin cancer”.

  68. Mick says:

    what is more worrisome is that guys lay awake at night worrying about this stuff. They should worry more about the regulations and taxes that result in this needless worrying.
    You know when the government says we created so many jobs this year? They create jobs for these over educated buffoons and all the administration that goes with it. Jobs shouldn’t need to be created, they should be the result of demand and growth. And government gets bigger and taxes increase.

  69. Steve Fitzpatrick says:

    fredburple,

    Several of your comments above suggest that you are a bit confused about how an infrared absorbing gas reduces the rate of heat loss to space. Your argument that GHG’s always cool the atmosphere is simply mistaken. GHG’s both absorb and emit photons at specific wavelengths. When a photon is absorbed, the GHG molecule is ‘promoted’ to an activated state, from which it can re-emit a photon of the same wavelength (in any random direction). But collisions with other molecules are very frequent, so following absorption of a photon the activated molecule is almost always immediately ‘quenched’ to the ‘ground state’ via collisions, before re-emission takes place, and the energy of the absorbed photon is therefore almost always converted to heat (‘thermalized’). The entire population of GHG molecules can, due to random collisions, be at any time briefly promoted to the ‘activated state’, and while in that state, may emit a photon in a random direction. There is always a very small population of GHG molecules in the activated state which are capable of radiating photons in random directions. At higher temperature, the population of molecules in an activated state (capable of emission) increases due to more vigorous collisions; at lower temperature the population decreases. So warming will always lead to greater emission by GHG’s in all directions, and cooling will always lead to less emission.

    The reason GHG’s reduce loss of heat to space is that absent GHG’s the surface would emit infrared photons directly to space (since the non-GHG’s in the atmosphere are essentially transparent in the infrared wavelengths), while space, with an effective temperature just above absolute zero, would emit essentially no photons back toward Earth…. near maximum radiative cooling as described by the Stefan-Boltzman law. With GHG’s in the atmosphere, there is always random emission of photons in all directions from GHG molecules, and those re-emitted in the direction of Earth represent ‘back-radiation’ at the Earth’s surface. Which means less net loss of heat via radiation to space.

    There are lots of very good reasons to doubt catastrophic projections of warming (the IPCC’s projections are consistently much too high, probably because their estimates of ‘feed-backs’ from clouds are much too high), but the basic physics of GHG warming in the atmosphere is well known and not seriously disputed.

  70. Mickey Reno says:

    It’s my understanding that the re-emission of IR by a molecule occurs in the same band as the absorption. Doesn’t that tell us that all the energy of the opaque bands is being converted to kinetic energy via conduction, to mostly O2 and N2 molecules?

    The energy is free to move in the other direction, too, of course. O2 and N2 molecules collide with GHG molecules and energize them. But because they have much less mass, less energy is imparted to the larger molecule via impact. And exciting a larger molecule to the point where it will emit IR takes multiple such collisions that apparently do not happen with enough regularity to cause emission to space in that band. But what about the bands which are only partially opaque? Don’t they tell us that all their energy comes completely from re-emissions, and those re-emissions must come from both conduction and absorption? Is it not apparent that all the energy absorbed in the opaque bands must eventually leave to space in partially opaque bands?

    So-called greenhouse gases are effective heaters of our atmosphere, not only because of the width of their absorption bands, but because they provide a 3-dimensional vector for the inefficient process of conduction. This vector is more or less unaffected by changes in the amount of GHGs, and argues for very low climate response due to any increases or decreases.

    Are there experiments that can test whether or not a much warmer atmosphere will increase the emissions in partially opaque bands, or even shrink (at the margins) the opaque bands, due to increased conduction?

  71. Greg says:

    george e. smith : April 11, 2014 at 7:48 am , sums it up nicely.

    In fact all this transmission stuff is based MODTRAN / HITRAN which is military atmospheric transmission software. I’d guess that this is probably the most though and accurate part of the whole modelling storey.

  72. Alan Robertson says:

    JudyW says:
    April 11, 2014 at 8:14 am

    The oxygen that methane combines with to form CO2 and H2O is ozone. The concern with methane is not it’s GHG properties but the ozone depletion aspect. This goes back to the scare before Global Warming of “We’re all going to die of skin cancer”.
    ___________________
    While that basis of argument has been deployed, the current tactic used by the scaremongers is that methane will cause warming, lots of warming. The actual reason that the methane scare is being promoted from on high is to raise the price of protein available to a hungry humanity.

  73. Ron C. says:

    Steve Fitzpatrick says:
    April 11, 2014 at 8:24 am

    Isn’t it the non-IR active gases, O2 and N2 that delay the cooling by capturing heat from the IR-active gases and then cannot radiate, but only rise and cool according to the lapse rate?

  74. Mickey Reno says:

    Amazing, as I was composing my last comment, Steve Fitzpatrick wrote his on exactly the same basic issues. Thanks, Steve. I had one more thought / question. When we measure the fully transparent IR bands from space, is there any systematic measurement of the emissions in those bands right next to the ground? Do we know that those bands energies are not actually enhanced by conduction in the atmosphere?

  75. scarletmacaw says:

    Tom, you should also add a graph depicting the LW radiation spectrum, since absorption outside the bulk of the LW spectrum contributes nothing to the ‘GH effect.’ The figure I found on a quick Google search isn’t great, but does give an idea. Maybe you can find a better one.

    http://www.earthonlinemedia.com/ebooks/tpe_3e/energy/solar_and_earth_radiation.gif

  76. Canman says:

    I’m not very impressed with this article. It leaves too many questions unanswered. Why is the range shown for CH4 so short? Is this the only range where CH4 absorbes IR? There is no source for the graph. The range in the video @5:11am shows half the escaping radiation occurring outside the range of the graph in this article.

    It does explain masking at the two CH4 spikes, but water vapor is not constant over the globe. It’s going to be less in colder areas.

  77. evanmjones says:

    All of that translates to a persistence of ~11 years. There has been continuing increase in methane release from 1970 — but at a continually decreasing rate of increase.

    If China stops showering coal dust all over the Eastern Arctic (which they will do long before cutting CO2), that will take off a lot of the warming pressure and there will be less CH4 emitted than is currently feared.

    CO2 has great persistence, and when an anthropogenic CO2 molecule is absorbed, it bumps aside a natural CO2, so it looks as if anthropogenic CO2 is going out of the system, but it’s just shifting around. The alarmists are right about that much. Because of the relatively long persistence of CO2, we need to keep a reasonably sharp eye on things. But without pushing the panic button six times before breakfast. And an eye favoring empirical evidence.

  78. Steven Mosher says:

    Not even wrong.

    The problem here of course is that the author doesnt understand the vertical structure of the atmosphere. yes, C02 and Ch4 overlap with water. The important thing is what is the atmosphere composed of where the radiation escapes.
    The definitive measurements of this were made in the 50s by the US Airforce.

    Here is what you need to know

    1) You still get an increase in warming even if the atmosphere is saturated because its absorption in the thin upper atmosphere that counts. The Air Force determined that the upper
    atmosphere was dry. The point is simple. you have to look at the concentrations at the point
    of escape: the ERL and above.

    2. Water vapor doesnt overwhelm either C02 or Ch4 because there is little or no water vapor
    in the cold high layer of the atmosphere where radiation escapes to space. The low pressure at that altitude makes what little water is there relatively ineffective.

  79. evanmjones says:

    Basically, methane (CH4) breaks down into H2O and CO2 (a minuscule amount). So, unlike CO2, when methane is gone, it’s GONE.

  80. Mike M says:

    “Unfortunately, this numerical reality is overlooked by most people.” Well yeah, because you never pointed it out to us until now. Only a couple weeks ago Obama said he wants to attack milk to stop global warming. http://articles.latimes.com/2014/mar/28/business/la-fi-methane-emissions-20140329 Stop the cows? What about stopping irrigating golf courses in Arizona?

  81. stevefitzpatrick says:

    Mickey Reno,

    There are spectral measurements looking up from the ground and looking down from space. The influence of GHG absorption bands is clear. (eg http://www.sundogpublishing.com/shop/a-first-course-in-atmospheric-radiation-2nd-ed/) If you don’t want to spend money, there is: http://people.su.se/~rcaba/teaching/PhysMetLectNotes.pdf.

  82. Joe Born says:

    Leonard Weinstein, Jeff Id, and stevefitzpatrick, thanks for the clarification.

    However, the comments weren’t very quantitative. Over how much of the infrared spectrum of interest is the stratosphere’s optical depth (if that’s the right term) significant? (I can’t blame you for not having all this at the tips of your fingers, but it never hurts to ask.)

  83. Billy Liar says:

    arthur4563 says:
    April 11, 2014 at 6:54 am

    I’ve decided that global wa[r]mists are climate chauvinists and a bunch of Dr Panglosses, all believing that this climate is the best of all possible climates, despite having only experienced
    this one.

    Isn’t that a bit too Candide for the warmists?

    I’ll get my coat.

  84. Phil. says:

    scarletmacaw says:
    April 11, 2014 at 8:45 am
    Tom, you should also add a graph depicting the LW radiation spectrum, since absorption outside the bulk of the LW spectrum contributes nothing to the ‘GH effect.’ The figure I found on a quick Google search isn’t great, but does give an idea. Maybe you can find a better one.

    Also such a low resolution spectrum such as the one in the OP is totally misleading, since as George points out it gives the illusion of overlap where there is none!

    Here’s high resolution spectrum showing the two gases, the top one being water, the much sparser lines of which give very little overlap with CO2.
    http://i302.photobucket.com/albums/nn107/Sprintstar400/H2OCO2.gif

    Here’s a spectrum through the atmosphere with the GHGs progressively remove starting with water, which is at a very low concentration higher in the atmosphere where the radiation to space actually takes place.
    http://i302.photobucket.com/albums/nn107/Sprintstar400/Atmos.gif

    By the way methane doesn’t react with O2 in the atmosphere it reacts with OH which is a scavenger molecule which is in short supply which limits the breakdown rate of methane.
    Methane when it reaches the stratosphere acts as a source of H20 there which otherwise has difficulty passing through the temperature minimum at the tropopause.

  85. stevefitzpatrick says:

    Ron C. says:
    April 11, 2014 at 8:39 am
    N2 and O2 do indeed ‘quench’ GHG molecules which have been promoted to an active state via absorption of a photon (a higher quantum energy state), and so do “take heat away from” the GHG molecules. But it works both ways: random collisions with N2 and O2 molecules can also promote a small number of GHG molecules to a higher quantum energy state, from which those GHG molecules can emit radiation. The difference in energy level between the two quantum energy states is equal to the energy content of the photon which is absorbed or emitted (energy is always conserved), so GHG’s have emission and absorption only at very specific wavelengths which correspond to the different “allowed quantum energy states” which the molecules can have. This is why GHG’s often have several distinct ‘bands’ of absorption and emission, with each band corresponding to a transition between two allowed quantum energy states.

  86. Jimbo says:

    Phew! That’s a relief in more ways than one. Just a few days ago a UK peer was talking a load of hot air.

    BBC – 9 April 2014
    Peer raises flatulence in climate change debate
    …..A hereditary peer has asked the government if it takes into account flatulence caused by baked beans in its climate-change calculations.

    Labour peer Viscount Simon, 73, raised concerns about the “smelly emissions” resulting from the UK’s unusually high consumption of baked beans. …..
    http://www.bbc.com/news/uk-politics-26957039

    http://chemistry.about.com/od/medicalhealth/f/What-Is-The-Chemical-Composition-Of-Farts.htm

  87. Ken Gregory says:

    The ratio of the percentages of water to methane is such that the effects of CH4 are completely masked by H2O. … Because of that, methane is irrelevant as a greenhouse gas. The high per-molecule absorption cross section of CH4 makes no difference at all in our real atmosphere.

    Sorry folks, but this is very incorrect. Changes in methane concentration do have a significant effect on climate. The figure of longwave radiative absorption by greenhouse gases shows the total absorption of the total atmosphere. In the real atmosphere, heat is transported upward by thermals and evapo-transpiration to above much of the water vapor. The water vapor concentration is low in the upper atmosphere, so this is where much of the heat energy is radiated out to space. (Several other commenters have also made this point.) The forcing effect of methane must be determined by line-by-line radiative code computer programs which take into account the declining water vapor with altitude.

    The direct radiative forcing due to the methane concentration increase in the industrial era after 1750 AD is 0.48 W/m2 (Forster et al., 2007). The IPCC WGI SPM page 13 correctly shows the direct concentration-based estimate of methane radiative forcing from 1750 is 0.48 [0.38 to 0.58] W m−2. (CO2 forcing was 1.68 W/m2)

    The methane concentrations increased from 722 ppb around 1750 AD to 1800 ppb. Most of the increase occurred prior to 1990 and has since leveled off. The actual CH4 concentration increased at 0.2%/year from 2005 to 2010. CH4 concentrations are forecast by the IPCC to increases at 1.34%/year by 2050 in the RCP8.5 scenario. The RCP8.5 methane growth rate by 2050 is 6.7 times the recent historical growth rate. The IPCC describes the RCP8.5 scenario as a “high emissions” scenario, but numerous reports incorrectly describe it as a “business-as-usual” scenario. The RCP8.5 is actually an extreme and unrealistic scenario as both CO2 and CH4 increases much faster than the historical changes. (CO2 concentrations increase at 0.54%/year from 2005 to 2013. The RCP8.5 CO2 concentrations increase at 1.00%/year by 2050, and at 1.16%/year by 2070, which is more than double the historical growth rate.)

    Methane is not likely to cause a significant temperature rise because the methane concentration is not increasing, not because the methane radiative absorption is “completely masked by H2O.”

  88. bcs says:

    dumb question: if co absorbs less heat than co2, why not eliminate catalytic converters from cars and take that part of co2 emissions out of the atmosphere?

  89. Rick says:

    O2 and N2 are non-radiative gases, they get warmed mainly by convection from ground and water. They can transfer heat by mixing with other gas components. They never realease heat by radiation. Why there is always talking about radiation or radiation balance? It’s the most ineffective way of heat transfer.

  90. DayHay says:

    stevefitzpatrick says:
    April 11, 2014 at 9:20 am
    If you don’t want to spend money, there is: http://people.su.se/~rcaba/teaching/PhysMetLectNotes.pdf

    Ok, skimmed the paper by Rodrigo Caballero. He seems to know several metric tons about the atmosphere and the various interactions. What does HE think about methane? This is the problem with the blogosphere, where we cannot seem to drive the stake of truth anywhere and convey what that actually means. Information gets published like this article, there seems to be some very good comments on why this is a simplistic analysis and not quite right, but again, what is right? Are spectral absorption lines so narrow as to preclude what looks like overlap? I guess I just need to be spoon fed the proof. After reading this thread I still have little idea if methane is the Mothra to the Godzilla of C02, and before I engage with the CAGW crowd, even though their arguments are every bit as vague, I (and it looks like we all) need more info.

  91. Blair M says:

    Glass should be – by all this GHG nonsense reasoning – termed a greenhouse solid. It is not! But it should. It – just like the so called GHG’s – is transparent to the visible, and blocks IR. And what about N2 and O2 – how can they trap IR heat and yet not be GHG’s? Just because they don’t show up with an instrument we all think they’re not GHG’s. It is the instrument that is special: N2 and O2 (98% of the atmosphere) are IR inactive to thermopile sensors – they are like stealth aircraft, they’re there, and loaded with energy (they have a heat capacity), but don’t show up. Read the instructions of any IR temperature instrument!! And end the Tyndall magic trick. All gases are ‘GHG’s.

  92. lgp says:

    Your graph shows molecular “bands” not individual molecular “lines” Unless H2O “lines” fall exactly coincident with CH4 “lines”, then H2O does not absorb the same photons as CH4. The photons that sneak between the H2O lines are the ones susceptible to absorption by CH4 lines (and vice versa). So yes, CH4 does matter as a greenhouse gas.

  93. DirkH says:

    Blair M says:
    April 11, 2014 at 11:23 am
    “All gases are ‘GHG’s.”

    No. Diatomic gases like N2 have no absorption bands, only a few harmonic needle peeks. They lack the many vibration modes of a triatomic molecule.

  94. DirkH says:

    lgp says:
    April 11, 2014 at 11:24 am
    “Your graph shows molecular “bands” not individual molecular “lines” Unless H2O “lines” fall exactly coincident with CH4 “lines”, then H2O does not absorb the same photons as CH4.”

    Oho! But did you consider the effect of gravity on the photon? It is redshifted when leaving Earth’s gravity well! So: Are you talking about the photons that go up or the ones that go down?

  95. DirkH says:

    Ken Gregory says:
    April 11, 2014 at 9:55 am
    “thermals and evapo-transpiration to above much of the water vapor. The water vapor concentration is low in the upper atmosphere, so this is where much of the heat energy is radiated out to space. ”

    By definition TOA is where the greenhouse gases radiate to space, so when a greenhouse gas occurs higher up, TOA is higher. So what.

  96. DirkH says:

    Steven Mosher says:
    April 11, 2014 at 9:03 am
    “1) You still get an increase in warming even if the atmosphere is saturated because its absorption in the thin upper atmosphere that counts.”

    I thought even warmists knew about Kirchhoff’s Law? so why do you talk about absorption only and not about re-emission? Is it ignorance or manipulative use of language?

  97. Ron C. says:

    Summarizing what people have said upthread: There are 3 ways that UWIR can pass from the surface to space.

    1) Some of the UWIR leaves directly, eg. All gases in our air are transparent to IR of 10-14 microns (sometimes called the “atmospheric window.”) This pathway moves at the speed of light, so no delay of cooling.

    2) Some UWIR is absorbed and re-emitted by IR active gases up to the tropopause. Calculations of the free mean path for CO2 show that energy passes from surface to tropopause in less than 5 milliseconds. This is almost speed of light, so delay is negligible.

    3) Bulk gases of the atmosphere, O2 and N2, are warmed by conduction and convection from the surface. They also gain energy by collisions with IR active gases, some of that IR coming from the surface, and some aborbed directly from the sun. Latent heat from water is also added to the bulk gases. O2 and N2 are slow to shed all this heat, and indeed must pass it back to IR active gases at the top of the troposphere for radiation into space.

    This third pathway has a significant delay of cooling, and is the reason why our surface has the temperature it does.

  98. DirkH says:

    Steve Fitzpatrick says:
    April 11, 2014 at 8:24 am
    “Isn’t it the non-IR active gases, O2 and N2 that delay the cooling by capturing heat from the IR-active gases and then cannot radiate, but only rise and cool according to the lapse rate?”

    No; under local thermodynamic equilibrium thermalization and dethermalization must happen to equal amounts (Kirchhoff’s Law); meaning – CO2 aborbs IR photons and gives energy to N2 and O2, but the reverse must happen equally often – N2 or O2 giving energy to CO2, making it re-radiate an IR photon.

    That’s why the term “heat-trapping gases” is a propaganda lie by the warmists.

  99. Richard M says:

    The methane releases by animals is unimportant. The carbon in the methane came from the food the animals ate. The carbon from the food came from CO2 in the atmosphere. The methane eventually breaks down within a decade. Hence, the carbon is simply being recycled. It is only the release of fossilized methane that might be a problem.

  100. Caleb says:

    Doesn’t the IR radiation originate from the surface if the earth, as it is baked by the sun? Doesn’t it then proceed upwards through the “greenhouse” gases?

    Would this not mean that a lot of the “blocking” occurs down low, where the gases are dense? And where water vapor is plentiful?

    As you got up to where the air is thin and water vapor is more scarce, wouldn’t much of the “blocking” have already occurred? Is not much of the IR radiation escaping earth occurring at wavelengths in the spectrum where “blocking” does not occur?

    Forgive me if I’m missing some obvious and major point, but everyone seems to be looking way, way too high. Once you get up where the air is too thin to breathe, so thin water boils at room temperature, the game is already over. That which was going to be blocked is blocked, and that which is escaping is heading off to Pluto.

  101. Ken Gregory says:

    DirkH says: “By definition TOA is where the greenhouse gases radiate to space, so when a greenhouse gas occurs higher up, TOA is higher. So what.”
    I have no idea what you are asking. The word “higher” is a comparison, so are you saying TOA is now higher than what it was in 1750 AD, or what?
    My comment refuted the author of the lead post conclusion that methane changes can have no effect on temperatures because “the effects of CH4 are completely masked by H2O.” Water vapor concentration is very low in the upper atmosphere, so H2O does not mask the effects of CH4. What did you not understand?

  102. dp says:

    If this is true:

    The vertical scale is upside-down: 100% absorption is low, and 0% absorption (i.e., transparency) is high.

    Then this is wrong:

    H2O absorbs strongly in the 3-micron region, and again between 5 and 7 microns;

    . The cannot both be right.

  103. Phil. says:

    DirkH says:
    April 11, 2014 at 11:38 am
    Steve Fitzpatrick says:
    April 11, 2014 at 8:24 am
    “Isn’t it the non-IR active gases, O2 and N2 that delay the cooling by capturing heat from the IR-active gases and then cannot radiate, but only rise and cool according to the lapse rate?”

    No; under local thermodynamic equilibrium thermalization and dethermalization must happen to equal amounts (Kirchhoff’s Law); meaning – CO2 aborbs IR photons and gives energy to N2 and O2, but the reverse must happen equally often – N2 or O2 giving energy to CO2, making it re-radiate an IR photon.

    Kirchoff’s law doesn’t say what you think it does! It just says that emissivity equals absorptivity.
    Also IR excites vibrational and rotational modes in CO2, multiple collisions with surrounding gases (N2 & O2) cause exchanges of translational energy in small packages. The transfer of energy from the N2 and O2 ( a very small fraction of which have excess energy sufficient to excite the vibrational level- see Boltzmann) to CO2 is most likely to excite translational modes not Ro-vib. As a result the CO2 is not likely to be able to emit.

  104. JeffC says:

    I was promised no scientific facts … now I have to actually read and understand … darn it …

  105. MikeB says:

    Phil. says:
    April 11, 2014 at 12:21 pm

    Kirchoff’s law doesn’t say what you think it does! It just says that emissivity equals absorptivity.
    Quite right Phil. But Dirk thinks it means that an object must emit as much radiation as it receives. He keeps saying this and no amount of correction will get him to think why that is obviously wrong.

  106. Leonard Jones says:

    No problem! Strap an inflatable bladder to the backs of cows and attach a hose with a
    check valve. Now, shove the other end of the hose up the cows ass. When the bladders
    are full, they can be taken to a power plant to generate electricity.

    Are these people INFREAKINGSANE? CH4 .0001745%
    1.745 parts per million, are you kidding me?

  107. lgp says:

    Re Dirk H “Oho! But did you consider the effect of gravity on the photon? It is redshifted when leaving Earth’s gravity well! So: Are you talking about the photons that go up or the ones that go down?”

    I also didn’t mention pressure broadening, doppler broadening (your red/blue shift) or line wings growing as line center absorption saturates. Even considering all that, unless the H2O lines are coincident with the CH4 lines, CH4 is still a green house gas.

    BTW detection H2O in stars was done a long time ago relying on the effect of pressure broadening, Hot H2O vapor in stars had broader spectral lines than cool H2O in earth’s atmosphere. So could subtract the contribution of terrestrial H2O from the spectra of stars to detect H2O in stars.

  108. george e. smith says:

    Kirchoff’s Law, and the common argument for it, are restricted to the case of thermodynamic equilibrium, presumably between the “EM radiation field” and the physical medium , which presumably has some defined Temperature.

    Solar thermal collection efficiency often depends on the use of spectrally selective surfaces, or coatings, that rely on the fact that the “absorption” of solar energy, is taking place at solar spectrum wavelengths; which correspond roughly to a 6,000 K black body spectrum; while the LWIR thermal emission from the collection surface, which might be at 100-200 deg. C will be spectrally at a totally different wavelength range, for which the emissivity is quite different from the solar spectrum emissivity.

    I think people trundle out Kirchoff’s law too often, and for no good reason; or good result either.

    I get spooked by Phil’s wavenumber based spectra, since I am not a chemist. So I don’t expect to find the CO2 absorption band right at the peak of the surface LWIR, instead of on the falling tail end.

    Readers need to appraised of an important distinction.

    The usual wavelength based spectra, a la the solar spectrum, have units of Watts per meter squared PER MICRON OF WAVELENGTH INCREMENT.

    The Chemist’s wave number based spectra, like the ones Phil linked to, have units of Watts per square meter PER WAVE NUMBER INCREMENT.

    So what ??

    Well on a wavelength based scale, the CO2 band is somewhat lower than the peak at 10.1 microns, for the 288 K LWIR spectrum, BUT there are a lot of MICRONS of band width, typically from around 13 microns up to around 17 microns..

    On Phil’s wave number based spectrum, the CO2 band is sitting on the spectrum peak, but there are fewer wave numbers down at the low end of the spectrum, whereas the much higher frequency solar spectrum, is up where there are plenty of wave numbers to spare, so even if the Y scale value is lower the PER WAVE NUMBER INCREMENT can add up to a lot of energy.

    So you have to pay attention to the scale units of these absorption spectra, so you are comparing apples to apples.

  109. BigFoot says:

    I live near a lot of cattle ranches. (The newborn calves in the fields these days are absolutely tiny!) One remark I often make to the city folk is that all you need to make a cow (and by extension, cow farts) is a field of grass and water. At the basics. Sure, you need the heifer and the bull, but think about it. A few cows and that field of grass and stream of water will create herd over time. So all those cow farts and everything else have come from the grass and the water. (Of course, let’s not forget the sunshine for the grass to grow).

    Does it matter how much methane is produced? It is all renewable. Everything a cow has, or is, or does, comes from the simplicity of growing grass (and carbon dioxide in the air), water and sunshine.

    To consider this a danger is to consider life itself a danger.

  110. Letelemarker says:

    A lot of what is being said in this comment section is beyond me, with people picking holes in other peoples explanation..interpretations…guess work.
    What does seem amazing clear though is that the earths climate system is massively complex and it has variables upon variables.
    I just can’t see how any computer model even has the scope to account for all of the factors involved, and the biggest limiting factor is that people are inputing the data/variables of system’s that are not fully understood. (we can’t even find a plane that was designed and built by people and probably has some of the best experts in the world looking for it)

    So does anybody really know what the hell is going on with the climate?.. the 97% of IPCC scientist? the people on here? (who seem to be in the minority, but do seem to come out with the most facts)..I have no idea, only time will tell I guess!

  111. Gary Pearse says:

    Steven Mosher says:
    April 11, 2014 at 9:03 am

    “Not even wrong.

    The problem here of course is that the author doesnt understand the vertical structure of the atmosphere. yes, C02 and Ch4 overlap with water.”

    We know LWIR is escaping the earth at a substantial rate. It must be coming from re-radiation well below the TOA. Surely if CH4 is so well mixed and it is 1.7ppm, there isn’t much of a “screen” for capturing this LW from below the TOA. What is wrong with my view of it.

  112. neillusion says:

    I find all this absorption/wavelengths/concentrations rather complex, so I try to simplify the question and look for the simplest answer that I can be sure of.
    So, in the question of do the so called GHG’s actually warm the atmosphere/planet. Rather than argue about the absorption/wavelengths/concentrations, surely there are data from detectors high up that directly measure the radiated energy (that CO2 & Methane would affect) leaving the planet?
    Do they exist?
    Are such data available?
    Have they shown less energy reaching those heights as CO2 and Methane increased?
    How would this explain the fact that the earth hasn’t warmed for over 17 years as CO2 & methane kept rising?

    I’m thinking that the warming ‘blanket’ atmosphere is very very thick, adding another thin blanket (so to speak) will not have any effect.
    Anyhow, the CO2 concentrations rise as the temperature rises as shown clearly by Salby & others.
    So I’m guessing the radiating energy of wavelengths under question is already absorbed 100% by what’s there.
    I think you could probably remove half or more of the existing blanket and the temperature/heat values in the atmosphere would stay the same.
    Does anyone know if above said data have been collected?

  113. Ken Gregory says:

    Leonard Jones says: “Are these people INFREAKINGSANE? CH4 .0001745%
    1.745 parts per million, are you kidding me?”

    No Leonard, this low percentage does not imply that methane changes have an insignificant effect on climate. What is important is the radiative forcing caused by methane. Since 1750, the change in methane concentration cause a radiative forcing of about 0.48 W/m2.

    However, the methane concentration in recent history has changed insignificantly, only 0.2%/year from 2005 to 2010. Also, climate is quite insensitive to changes in greenhouse gas forcing.

    The CERES satellite with surface temperatures measure the changes in the greenhouse effect from 2003. Using HadCRUT4 and CERES outgoing longwave radiation data, a doubling of CO2 with a forcing of 3.71 W/m2 would cause a transient temperature response of only 0.74 +/- 0.54 C (95% confidence). The transient climate response is 0.20 C/W/m2. This is a staight forward calculation because during the CERES era, there was no net change in surface temperatures, so there were no net feedbacks. See:
    http://www.friendsofscience.org/index.php?id=739

    From 2000 to 2012, CO2 changes were 84.9%, and CH4 (methane) was 3.3% of the total greenhouse gas radiative forcing, so methane was insignificant.

  114. Steve Fitzpatrick says:

    DirkH says:
    April 11, 2014 at 11:38 am
    I do not know who you think you were quoting, but it surely was not me who wrote what you quoted. You are also very confused about Kirchoff’s law and what it means. In any case, based on your several comments up thread, I very much doubt I, or anyone else for that matter, can help you understand radiative heat transfer. A Deus.

  115. Paul Linsay says:

    Methane is buried by H2O, it’s effects should be minimal. Download the accompanying atmospheric absorbance poster created by the Air Force Research Lab and Spectral Sciences to see this.

    https://dl.dropboxusercontent.com/u/3758743/AtmosphericTransmission.pdf

    I’m not at all convinced that conduction and convection don’t swamp the minimal amount of heating by back radiation from CO2.

  116. Steve Case says:

    The climate sensitivity of CO2 is about 1.2C° per doubling in the atmosphere

    The climate sensitivity of CH4 is about (___)C° per doubling in the atmosphere

    Can anyone fill in the blank?

  117. stevefitzpatrick says:

    DayHay, April 11, 2014 at 11:00 am
    There are no simple ways to answer your detailed questions. What is pretty clear is that methane for certain adds to total GHG forcing (as some have noted, a net of ~0.48 watt/M^2, but with some uncertainty). Would adding a bunch of methane to the atmosphere increase GHG forcing? For sure it would. Is there much chance forcing from methane is going to skyrocket in the coming decades? For sure there is not. Giant methane releases from methane clathrates, either from the oceans’ deep continental shelves, or from deep permafrost melting, is so far from reality as to be laughable…. which is why worrying about methane is nuts. This all falls in the “scary story” realm of climate pseudo-science which the late Stephen Schneider advocated: “So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have.”

  118. Kevin Roche says:

    this is a very informative comment stream. Would someone please explain, though, why we would care if the the upper atmosphere, which is where people seem to be saying the action of gas molecules like CO2 and Methane predominates, gets warmer? What does that have to do with the surface or near surface temperature. If what is absorbed and prevented from going out into space is then re-radiated in part downward, would it not randomly again be re-radiated in part upwards. Eventually everything goes out the top to space and the layer right next to space may be a little warmer but I am unclear by why other layers would be warmer. Just trying to understand how you possibly end up with a net warming at the surface if the “heat” capture is at the top of the atmosphere, which is a long way up.

  119. scarletmacaw says:

    Ken Gregory says:
    April 11, 2014 at 2:29 pm

    Since 1750, the change in methane concentration cause a radiative forcing of about 0.48 W/m2.

    Why 1750? What’s so special about that particular date?

  120. Steve says:

    Dr. Sheahen – 3 questions: 1) is it known whether there is any affinity associated with IR wavelength and each of the molecules in the overlapping bands? That is, because H2O, CO2, etc. are of different configurations and atomic weights, would a particular wavelength excite an H2O molecule “in preference” to a CO2 (or other) molecule? 2) has anyone quantified the IR energy being given off by Earth? That is, do we know how much energy the Earth is producing or reflecting back into the atmosphere at each wavelength? And 3) What happens to the excited molecule? I assume it almost instantaneously returns to its non-excited state and releases energy at an even lower wavelength.

    I ask because, if there is an affinity and that affinity is stronger toward H2O, then other GGs are pretty much irrelevant. OR, if Earth is producing little or no energy in the wavelengths associated with CO2 or CH4 then, again, they are irrelevant.

  121. Wandering_Curmudgeon says:

    I really fail to understand how so many people could gloss over the TRILLIONS of people already killed by that awful CAGW. This methane problem must be stopped immediately. I propose that all person eating baked beans along with all those involved in preparing them for consumption, canning them for preparation, selling, transporting, harvesting or growing them be arrested, terminated with extreme prejudice and then tried in absentia. After that, we should go after those responsible for the pockets of over-heated CO2 clustering around state and national capitals . . .

  122. Long John says:

    I was pulled over by a policeman wearing a green hat the otherday and asked to blow in his fartometer. Most embarassing. Fortunately I’d followed the government’s new guidelines on keeping fart gas below the permissible volumes.

  123. Stephen Brown says:

    The Warmista Politicians here in the UK are now seeking to control human farts in order to ‘save the Planet’.
    http://www.dailymail.co.uk/news/article-2600681/Cut-eating-baked-beans-reduce-smelly-emissions-minister-suggests-battle-tackle-climate-change.html

  124. Nullius in Verba says:

    “Would someone please explain, though, why we would care if the the upper atmosphere, which is where people seem to be saying the action of gas molecules like CO2 and Methane predominates, gets warmer? What does that have to do with the surface or near surface temperature.”

    The greenhouse effect requires the understanding of two separate bits of physics: radiation of heat in a vacuum, and the adiabatic lapse rate.

    First, the Earth absorbs energy from sunlight, and radiates energy to outer space as thermal IR. The Earth warms or cools until the energy radiated by the emitting ‘surface’ balances the energy absorbed, which happens at a temperature of about -18 C. However, the surface emitting to space isn’t the solid ground, because the atmosphere is partially opaque at IR wavelengths. The emitting ‘surface’ of the Earth appears to be about 5 km up on average. (You can think of it as a bit like fog, visually. Obviously I’m hand-waving over a lot of technical detail, here, to calculate/interpret that average height.) So it’s the layer 5 km up that settles at -18 C.

    The second bit of physics is that gases tend to increase in temperature when they are compressed, and cool when they expand. And pressure decreases with altitude. So as convection drives air round convective cycles, it warms as it descends and cools as it rises. This means that convection turns on and off as the vertical gradient exceeds or falls below the rate of compressive warming, and this acts as a sort of thermostat that holds the *gradient* very close to a constant called the ‘adiabatic lapse rate’. Note that only the gradient is fixed, not the offset.

    We modify this slightly to account for the condensation/evaporation of water, which has a very similar altitude effect. The result is called the ‘moist adiabatic lapse rate’, and is about 6.5 C/km of altitude, although it varies a bit depending on humidity.

    So the surface temperature will be warmer than the emitting layer by an amount equal to the gradient times the height difference between the two. The gradient is about 6.5 C/km, the average height difference about 5 km, so the surface is 33 C warmer than the emitting layer, or +15 C.

    When you add greenhouse gases, the atmosphere becomes more opaque, and the emitting layer appears to be higher. The increase in altitude makes the surface warmer.

    This is the official, mainstream mechanism for the greenhouse effect, as used in the technical literature. (e.g. Soden and Held 2000, Manabe and Strickler 1964, Sagan 1967, etc.). Accept no substitutes!

    As several people have noted, at the top of the atmosphere there’s not much H2O, so other gases have a much stronger effect on emission altitude. Methane has a significant effect (I think) between 1200-1400 cm^-1 at the upper tail of the thermal black body distribution, raising the altitude of emission in this band significantly. Overall, it’s not a big deal. But its not zero.

  125. Steve Fitzpatrick says:

    Kevin Roche,
    “Would someone please explain, though, why we would care if the the upper atmosphere, which is where people seem to be saying the action of gas molecules like CO2 and Methane predominates, gets warmer?”
    Well, because that means the surface has to become warmer as well. Most (~70%) visible and near infrared solar energy (that is, less than a couple of microns wavelength) is absorbed by the surface, either ocean or land. That visible and near infrared energy is converted to heat and that heat must be lost to space at the same rate as it is gained (on average) or the surface temperature rises. There are different ways heat leaves the surface (infrared radiation, convection, latent heat). Each of these heat losses depends mainly on a difference in temperature between the surface and some higher altitude in the atmosphere… only a modest amount of heat is lost to space directly from radiation from the surface (see the “atmospheric window” in Wikipedia). So when the temperature aloft is warmer, the driving force to transport heat from the surface is less….. unless the surface warms as well, restoring the required level of driving force to maintain energy balance. That is the primary way GHG forcing warms the surface.

    None of this is very controversial. Direct GHG forcing would lead to ~1.1C to ~1.2C of warming for a doubling of CO2, which is clearly not enough to worry about. The real disagreement is in “amplification” of this warming. There are two types of amplification, one more doubtful than the other. The first is that warming at the surface (and throughout the troposphere) will increase the concentration of water vapor. Higher water vapor acts as a greenhouse gas, and so “amplifies” the direct warming by further restricting the loss of heat to space. That is, GHG’s cause a bit of warming, that warming causes a bit of increase in water vapor; the higher water vapor further restricts loss of heat to space, leading to more warming. The exact extent of water vapor amplification is somewhat uncertain, but a reasonable range is a 40% to 70% increase over the ‘bare’ GHG warming, or maybe 1.5C per doubling of CO2 to 2C per doubling of CO2. The upper end of this range is of modest long term concern, but would never be an “existential threat” under any plausible circumstances.

    The second type of amplification is what I consider ‘wildly speculative’, including net warming from clouds, change in snow/ice albedo, and others…. all of which are extremely uncertain. The best empirical data is that these other amplifications are minimal, or perhaps even negative. Yet most climate models are based on assumed (‘parameterized’) amplification from clouds and other factors that is very large…. bringing net warming to ~3.2C per doubling of CO2 on average for the models, and in some models, reaching more than 4.5C per doubling of CO2. Here is where climate models diverge sharply from reality… empirical data says they are simply wrong about the second type of amplification. Which is why most climate models are, IMO, little better than rubbish when it comes to making useful predictions of warming. The only rational way to deal with current model projections of warming is to ignore them.

    Hope that helps.

  126. Ken Gregory says:

    Steve Case says:
    “The climate sensitivity of CO2 is about 1.2C° per doubling in the atmosphere
    The climate sensitivity of CH4 is about (___)C° per doubling in the atmosphere
    Can anyone fill in the blank?”

    The climate sensitivity of CH4 is about (_0.11)C° per doubling in the atmosphere.

    The climate sensitivity of CO2 you gave of 1.2 C per doubling is the no-feedback response. The IPCC models give an average feedback multiplier of +2.75. The CERES data suggests the feedback multiplier is 0.4.

    The IPCC WII TS page 52 says CH4 increased from 722 ppb in 1750 to 1803 ppb in 2011. The report claims this results in a direct forcing of 0.48 W/m2. Therefore, a doubling of CH4 would cause a forcing of 0.36 W/m2, calculated by 0.48 x ln(2)/ln(1803/722). The Planck response is 3.2 C/W/m2. Therefore, the no-feedback climate sensitivity of CH4 is 0.11 C, (0.363 W/m2 /3.2W/m2/C). This assumes you wait a thousand years of oceans to reach equilibrium. The transient climate response based on AR5 Table 9.5 would be 56% of that, or just 0.062 C. However, at the current CH4 growth rate of 0.2% per year, you would have to wait 347 years to double methane.

  127. Joe Born says:

    Kevin Roche: “Just trying to understand how you possibly end up with a net warming at the surface if the “heat” capture is at the top of the atmosphere, which is a long way up.”

    Long-term, the radiation out of the earth equals the radiation in, so the radiation temperature is fixed, and the higher up the effective altitude of that outward radiation, the greater, for a given lapse rate, must be the surface temperature. Greater greenhouse-gas concentration means higher effective radiation altitude means a greater distance over which the lapse rate raises the surface temperature.

    This is over-simplified, of course, since the optical distances are different at different wavelengths and different latitudes, but I believe that’s the general idea.

  128. stevefitzpatrick says:

    Steve Case,
    “The climate sensitivity of CH4 is about (___)C° per doubling in the atmosphere”

    My SWAG is about 0.45C per doubling of methane….. but anything close to doubling methane is extremely unlikely; more likely is that methane’s trend can be safely ignored.

  129. Ken Gregory says:

    scarletmacaw says: “Why 1750? What’s so special about that particular date?”

    1750 is the date the IPCC has chosen for the start of the industrial revolution. Their table of radiative forcings Figure SPM.5 is relative to that date. The CDIAC table of CO2 emissions starts in 1751.
    http://cdiac.ornl.gov/ftp/ndp030/global.1751_2010.ems

  130. DJ says:

    Funny that the methane producing cows could also be the solution…. If used properly…

  131. DirkH says:

    Steve Fitzpatrick says:
    April 11, 2014 at 2:36 pm
    “DirkH says:
    April 11, 2014 at 11:38 am
    I do not know who you think you were quoting, but it surely was not me who wrote what you quoted. You are also very confused about Kirchoff’s law and what it means. In any case, based on your several comments up thread, I very much doubt I, or anyone else for that matter, can help you understand radiative heat transfer. A Deus.”

    You mean I’m incorrigible? Now that’s just TOO BAD.

    WHY do you not bring ANY argument against what I said? Maybe because you have none? :-)

  132. DirkH says:

    Phil. says:
    April 11, 2014 at 12:21 pm
    “Kirchoff’s law doesn’t say what you think it does! It just says that emissivity equals absorptivity.”

    A distinction without a difference.

  133. DirkH says:

    If I were wrong the warmists would have their tropospheric hotspot but they don’t.

  134. Nullius in Verba says:

    “If I were wrong the warmists would have their tropospheric hotspot but they don’t.”

    The tropical hotspot has nothing to do with radiative physics. The theory is that a warmer atmosphere will be moister, and that will reduce the moist adiabatic lapse rate. A shallower lapse rate means that altitudes below the average emission-to-space altitude warm less and altitudes above it warm more. So a moister atmosphere partially cancels the greenhouse warming near the surface (i.e. lapse rate feedback is negative), while reinforcing it at higher altitude.

    The lack of a tropical hotspot may be due to one of two things – either the surface temperature measurements are biased upwards, so we’re looking for a bigger effect than is actually there, or the atmosphere is not getting moister at the rate the models expect. This of course would imply that the water vapour feedback, that multiplies a 1.2 C/2xCO2 sensitivity to a scary 3.5 C/2xCO2 sensitivity, is likely not correct.

    But it’s got nothing to do with radiative physics.

  135. davidmhoffer says:

    Leonard Weinstein says:
    April 11, 2014 at 5:58 am
    + 1

    Steven Mosher on same issue
    +1

    I skimmed most of the rest of the comments. If water vapour was well mixed throughout the atmosphere, this article would be accurate. But it isn’t well mixed, it precipitates out at high altitude and high latitude while other gasses, CO2, CH4, O3 do not. Hence the the overlap in absorption spectra with H2O is immaterial for the majority of the atmospheric air column.

  136. Steve Case says:

    Earlier I asked:

    The climate sensitivity of CH4 is about (___)C° per doubling in the atmosphere
    Can anyone fill in the blank?

    Ken Gregory said 0.11C°
    stevefitzpatrick said 0.45C°

    Some time ago I searched the internet with the question, “Why is CH3 reported to be 20 times more powerful as a greenhouse gas than CO2?” And the answer I came up with is, it’s because it’s at such a low volume in the air it doesn’t take much to double, quadruple etc. So whatever its sensitivity is, it’s easily multiplied into significant increases in temperature with relatively small absolute quantities of CH3.

    So thank you Greg & Steve for your response.

  137. leftturnandre says:
    April 11, 2014 at 4:17 am
    The mega methane mania finds its roots in the Greenland ice cores where it was observed that large fluctuations of methane coincided with fluctuation in stable hydrogen and Oxygen isotopes (erroneously considered a paleothermometer). Especially around the erroneously considered cold Younger Dryas. To the cherry pickers it looked like the methane spikes had caused sudden large temperature swings, like the ‘more-than-ten-degree-within-a-decade’stuff of Richard Alley and friends.
    ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    Mosher posted a video of Richard Alley the other day at the AGU in 2009 I think. I watched the whole thing as it got really interesting when Alley said climate changes in the past were tied to orbital changes of the earth and changes in the perihelion and axis tilt; and that CO2 followed warming. It appeared that his message was that “things are different this time” because MAN is introducing CO2 into the atmosphere – but then he talks about mass extinctions due to natural warming due to orbit variation AND huge vulcanism that caused the oceans to be seeded with nutrients. He talks of warming of the Atlantic ocean to 30 some degrees Celsius and then massive acidification due to biological masses. And then in the end he talks of the effect of AGW in a time frame of hundreds of years or perhaps a millennial scale.

    So, I am supposed to worry about something that might happen a few hundred or a thousand years from now? Plus Alley himself pointed out the huge natural variations in the past. Is it not likely that those variations could cause temperatures to move one way or another in spite of human activities? And given those time scales, I would think humans will have moved on to new sources of energy besides fossil fuel.

    So, being an old fossil myself, I am having trouble getting really excited about a little CO2. I do worry about long lasting chemical pollutants and energy for my grandchildren.

    In the meantime, I just bought a new pair of powder skis on sale today so off to the mountains to try them out.

    Have a great weekend and enjoy life.

  138. DesertYote says:

    A couple of years ago I tried to postulate that the logarithmic nature of radiative forcing due to greenhouse gasses was independent of the species of gasses involved. All I got was grief. No one could understand what in the world I was talking about. I even tried to explain it by describing a simple experiment and stating the likely outcome. And I got grief over that. Everyone just assumed I was just some redneck without any scientific understanding. That assumption appears to have blinded them from actually reading what I was trying to say. This incident really soured me on the WUWT community. So now I tend to keep my comments to anti-Marxist snark.

  139. Nullius in Verba says:

    “All I got was grief. No one could understand what in the world I was talking about. I even tried to explain it by describing a simple experiment and stating the likely outcome. And I got grief over that.”

    We’re sceptics. We’re sceptical of everybody and everything. And we all have our own competing theories, of which we are each utterly convinced, and not all of us can be right.

    The idea is that science is like a gladiatorial arena. You put your pet theory into the ring, and everybody attacks it simultaneously from all sides. If your theory survives, it gains in credibility. The more vicious the attack it can survive, the stronger it is shown to be. This is a good way to think of it, it makes it easier to accept the criticism. But nobody likes to see their beloved pet theory being mauled.

    Regarding that logarithmic relationship, what happens to it as the concentration approaches zero? What is the logarithm of zero? Can that be right?

  140. WillR says:

    So millions of beef cows are causing the climate to change…

    Just over a century ago millions of buffalo were roaming the western plains of North America. Is it possible that their methane (flatulence) caused the current warming cycle?

    Just asking…

  141. Alex says:

    Looking at transmission graphs can very deceptive. They say nothing about the energy of those absorptions/emissions. To get a realistic view they should be incorporated in an energy/wavelength graph -blackbody curve. Then you could see quite clearly how much energy is transmitted. Area under a curve. Transmission graphs don’t tell you if you are transmitting a creek or a mighty river of energy.

    REPLY: go ahead and work that up then, and we’ll add it as an addendum – Anthony

  142. Alex says:

    Sorry, I don’t know how to add images to blog comments

  143. Willis Eschenbach says:

    Dr. Tom, a most interesting post. I never considered that.

    Of course, being a man who checks everyone, I went to MODTRAN to check your assertions. I found the following increases in longwave absorption if we double the methane concentration. Here’s how absorption increases when you double the methane.

    Clear Sky Tropics +0.75 W/m2 from doubling of methane
    Clear Sky US Standard Atmosphere +0.69 W/m2
    Clear Sky Subarctic Winter +0.34 W/m2

    Note that these are reduced somewhat if there are clouds. On a global average, then, it seems that a doubling of methane would lead to an increase in absorption of somewhere around half a W/m2 … color me totally unimpressed.

    So your claim is upheld by MODTRAN, my congratulations … always more for me to learn, thanks for schooling me on methane.

    w.

  144. bones says:

    Cross sections for CO2 in cm^2 per molecule
    http://vpl.astro.washington.edu/spectra/co2pnnlimagesmicrons.htm
    Cross sections for CH4 in cm^2 per molecule
    http://vpl.astro.washington.edu/spectra/ch4pnnlimagesmicrons.htm
    Cross sections for H2) in cm^2 per molecule
    http://vpl.astro.washington.edu/spectra/h2opnnlimagesmicrons.htm

    For well mixed atmospheric gas constituents, the fraction of beam absorption per meter of gas column by each type of molecule at a given wavelength will be proportional to the molecule’s cross-section at that wavelength and also proportional to the number of molecules of that type. These have to be summed over the earth surface thermal emission bands in order to see which molecules absorb the most energy. Water vapor, because of its great numbers of molecules is dominant, but there is significant absorption by both CO2. The low numbers of CH4 result in much less energy absorbed by it. It has a fair sized cross-section but very low numbers.

  145. bushbunny says:

    Only ruminants burb and methane, and methane doesn’t stay around as long as carbon dioxide.
    We do too, and kangaroos are not ruminants. That’s why Ross Garnaut suggested farmers turn to farming kangaroos instead of sheep and cattle. Very hard as they are marsupials, and don’t taste as nice as lamb and beef.

  146. bushbunny says:

    Sorry I am tired, it should have read …’only ruminants burp and fart methane…”

  147. DesertYote says:

    Nullius in Verba says:
    April 11, 2014 at 8:08 pm

    ####

    That is not what happened. No one came close to even trying to understand what I was saying. As for the relevance of their comments, they might as well have been grammar nazis. For instance, when I tried to explain a laboratory experiment, no one caught on to that fact. “But the atmosphere is not well mixed”. Well, duh. That’s NOT what I was talking about, and was not relevant to a discussion on the nature of gasses.

    BTW:

    ln| 1 + q|, q = 0 results in 0

    sheesh

  148. DesertYote says:

    Nullius in Verba says:
    April 11, 2014 at 8:08 pm
    ####

    Another thing, its not concentration (parts gas a / total parts atmosphere) that is impotent, but density ( parts gas a / volume).

  149. DesertYote says:

    bushbunny says:
    April 11, 2014 at 9:45 pm
    ###

    Vegans produce more CO2 then people with a normal diet.

  150. bushbunny says:

    I didn’t say this, the vegan diet tends to be very low in B.12. And they don’t produce any more CO2 than people on a balanced diet or vegetarians.

  151. StefanL says:

    Many thanks to : Nullius in Verba (4:16 pm), Steve Fitzpatrick (4:24 pm), Ken Gregory (4:28 pm) and Joe Born (4:31 pm). A very clear and understandable summary of the GHG effect.

  152. gymnosperm says:

    MikeB,

    ” The atmosphere is therefore opaque to radiation at 15 microns”

    This is not true. Look at any wavelength by intensity graph and you will see light gets through:

    http://geosciencebigpicture.com/2014/03/31/spectra-goddess-of-light/saturated/

    You are correct in your assertion than most 15 micron outgoing is absorbed close to the surface, but that is precisely where water vapor is concentrated. Being better mixed CO2 would predominate at higher altitudes but it is saturated by Beer Lambert per Gavin Schmidt’s own graph:

    http://wp.me/a1uHC3-hc

    Everyone seems to forget that methane has a short half life in the atmosphere and degrades to CO2 and water, the real man’s greenhouse gas.

  153. Lil Fella from OZ says:

    Must be a lot of methane in Africa. Elephants watch out.

  154. aGrimm says:

    Another poster spoke to this, but the point needs a little expansion. As wavelength is directly related to energy, I prefer to use the term energy as it is less esoteric to most folks than the word wavelength.
    When a photon is absorbed by an atom or molecule (a/m), the a/m gains energy and is in an excited state. The a/m does not like to be in this state and it will eventually try to return to its natural ground state. Time frames vary widely for when the energy will be lost, and may depend on other environmental conditions. There are a number of ways the extra energy may be lost. Remembering that energy is always conserved, here are some of the ways the a/m might lose the extra energy to get back to its ground state:
    1) Emission of a photon. The emitted photon(s) may be of the same energy as the received photon, or may be of any other lesser energy value. The resulting photons are free to interact with another a/m.
    2) Direct transfer of the energy to a different a/m. All or some of the energy may be transferred. The new a/m now has excess energy it needs to deal with. Sidebar: A radiation counting technique, liquid scintillation counting, takes advantage of direct energy transfer.
    3) Re-arrangement of a molecule. The extra energy can be the catalyst for molecular transformation, e.g. breakdown, or to make the molecule susceptible to a chemical reaction with another molecule.
    The gist of this article is that the factors influencing energy absorption and subsequent deposition of that energy are:
    1) the atom or molecule’s energy absorption bands. Every atom or molecule has specific absorption bands. The molecule is opaque to all other energy bands. (I’m ignoring other methods of radiation interaction, such as particulate radiation, that may deposit energy within an a/m).
    2) The quantity of a/m’s available. The more atoms, the greater the chance for photon interaction. there are a lot more H2O molecules in the atmosphere than CO2 molecules.
    3) The quantity photons available in the specific absorption range of the a/m. Because there are fewer CO2 molecules, in a large field of specific range photons, each gains extra energy which will want to go somewhere, e.g. H2O molecules, any other molecule such as your skin (what we perceive as warmth is energy transfer from excited molecules), and even emission into space especially if the excess energy is emitted at a wavelength that is not in CO2’s energy range or the range of other GHG’s.
    Honestly, except for climate folks like Leif, Anthony and many other good climate scientists, I think the interaction of radiation with matter is poorly understood by some really poor climate scientists, of whom we are acutely aware. I see many commenters here amazed that they have not heard about the crux of this article’s focus. I am not amazed at this reaction. About the only place you will find the study of radiation interaction with matter is within radiation physics, which few get. The interaction of radiation with matter is critical to an understanding of GHG’s role in our climate.

    For any physicists who may want to get into electron energy levels, photon wave and particle functions, and all the other cool micro world theories, let’s not go there such that we may give the many here a basic understanding. Once they grasp the basics, they can go to folks like Lubl and get a deeper understanding if they like. I am very pleased with Sheahen’s effort to keep it simple in this article. Well done.

  155. MikeB says:

    The forcing from methane is not logarithmic like CO2. I did say earlier that its effect was linear but that is wrong too. Here is what the IPCC has to say…

    “The existing concentrations of a particular gas dictate the effect that additional molecules of that gas can have or gases such as the halocarbons, where the naturally occurring concentrations are zero or very small, their forcing is close to linear in concentration for present-day concentrations Gases such as methane and nitrous oxide are present in such quantities that significant absorption is already occurring and it is found that their forcing is approximately proportional to the square root of their concentration Furthermore, there is significant overlap between some of the infrared absorption bands of methane and nitrous oxide which must be carefully considered in calculations of forcing For carbon dioxide, as has already been mentioned, parts of the spectrum are already opaque that additional molecules of carbon dioxide are even less effective, the forcing is found to be logarithmic in concentration”

    So, the IPCC says the forcing effect from methane is proportional to the square root of its concentration. It is not logarithmic and so ‘the effect per doubling’ is not a valid concept since this will depend on the starting concentration.
    I tried to check this on MODTRAN but the results were baffling. No time to sort it out.

    Nullius in Verba April 11, 2014 at 4:16 pm —- Very Good.

  156. DesertYote says:

    bushbunny says:
    April 11, 2014 at 10:37 pm

    I didn’t say this, the vegan diet tends to be very low in B.12. And they don’t produce any more CO2 than people on a balanced diet or vegetarians.
    ####

    I said this mostly to be funny, but the truth is that vegetarians do indeed produce significantly more gas, which contrary to popular belief, is not mostly CH4, but CO2. And for the humor impaired, this is funny because the anti-meat activists are promoting the cattle – greenhouse gas connection as a talking point to attack the cattle industry.

  157. MikeB says:

    gymnosperm says:
    April 11, 2014 at 11:15 pm

    Look at any wavelength by intensity graph and you will see light gets through:

    It is not getting through! What you are seeing in the graph you link to is radiation being re-emitted from the top of the CO2 fogbank (see Nullius in Verba April 11, 2014 at 4:16 pm ).
    The atmosphere is absolutely opaque at 15 microns because of CO2.

  158. J Martin says:

    Richard M at April 11, 2014 at 11:40 pointed out that cow farts just get recyled back into co2 and then back into the grass they eat, so they add nothing extra to the atmosphere. Good point. As for permafrost melting, the Russians who have most of it say that the permafrost is NOT melting.

  159. Twobob says:

    A sigh is but a spout of wind coming Or the heart.
    But should it take a downward trend, tis oft times called a Fart.
    Now to fart tis but a pleasure, it gives the bowels ease.
    It scents and warm the bed clothes and suffocates the fleas!

  160. aGrimm says:

    @ Mike B – I’m having troubles finding your Nullius reference; could you post the URL for it?

    Gymnosperm is referring to a broad spectrum of energies (wavelengths) such as visible light and is quite correct. For example visible light, generally defined in the 400-700nm range and which is not in the CO2 wavelength/energy absorption band, does get through CO2 – as does all the other wavelengths (including the other IR wavelengths) that CO2 does not absorb.

    CO2 absorbs energy as photons which are in the IR range. IR has a longer wavelength, and therefore has less energy associated with the photon, than a visible light photon. It has a greater energy than a radio photon. (You may know this, but this is for others)

    As a single CO2 molecule absorbs photon energy, it becomes “saturated”, meaning it will not absorb any more energy without releasing energy. It can and may hold the initially gained energy for awhile. However, the molecule does not want to stay in an excited stated of extra energy forever and depending on environmental conditions will eventually shed the energy by one of the routes I noted in my previous post. If the saturated molecule gets hit by another “correct” wavelength/energy, the highest probability is that the extra energy will be immediately emitted – in any direction – as a photon with the same energy in which it came.

    I don’t know what you mean by a “fogbank” of CO2″. I’m assuming you mean a large area with lots of CO2 molecules in it, and only CO2 molecules, which are absorbing the right energy photons. Let’s say a box full. Let’s say IR light is coming from only one direction like (sort of, kind of) sun light does. As each CO2 molecule gets saturated, any further hits are transferred – in any direction. Other CO2 molecules might absorb this energy but then also become saturated. If all the molecules become saturated, any excess input energy will just depart from the box. There will be other energy losses such as other molecules getting excited via direct energy transfer or the molecules happen to absorb degraded (lesser energy) photons from the saturated CO2 molecules, which is why the box may feel hot as those molecules give up their energy. Even long before saturation of all the CO2 molecules, you will start seeing IR (in CO2’s absorptive range) above the fog, below the fog, and to the sides of the fog if an excess photon deflects and goes outside the CO2 fog area.

    However, in the sense that all photons in CO2’s absorption range are highly likely to get absorbed, this is true, but not just because of CO2. Water will absorb in the same range. There are a LOT more molecules of water in the air and with a broader IR absorption range than CO2,

    The concepts of radiative and energy transfer are fairly easy to grasp. However, it is what happens to the energy that starts boggling the mind. With even just one radiative transfer we can only imperfectly predict statistically as to where that energy will go, We cannot predict its actual endpoint with certainty. If we cannot do this with one interaction, how does anyone think we can do it in such a gigantic, complex system as our climate? CAGW from a physics point of view has to be the worst scientific hubris that mankind has seen.

  161. Lewis P Buckingham says:

    Gary Pearse says:
    April 11, 2014 at 1:56 pm

    Steven Mosher says:
    April 11, 2014 at 9:03 am

    “Not even wrong.

    ‘The problem here of course is that the author doesnt understand the vertical structure of the atmosphere. yes, C02 and Ch4 overlap with water.”

    We know LWIR is escaping the earth at a substantial rate. It must be coming from re-radiation well below the TOA. Surely if CH4 is so well mixed and it is 1.7ppm, there isn’t much of a “screen” for capturing this LW from below the TOA. What is wrong with my view of it.’

    Intuitively any methane molecule near the TOA would emit a photon in any direction in a random fashion depending upon its vibration.
    Photons heading earthward would be likely to be absorbed by GHG’s or reflected by clouds.
    Photons heading into space would end up being lost to space, the ultimate heat sink.
    Thus the net effect of these GHG methane molecules near the TOA ,where water vapour is scarce, would be cooling.

  162. richard says:

    Adding to
    Joe Born says:
    April 11, 2014 at 4:31 pm
    Kevin Roche: “Just trying to understand how you possibly end up with a net warming at the surface if the “heat” capture is at the top of the atmosphere, which is a long way up.”

    —————————-

    off tangent onto co2,

    I need to understand as well- where is there a point at which any warming higher up has an effect at or below lower clouds, surely there is such a river off energy flowing upwards that any co2 absorption ( at 15 microns) when re-emitted ( i assume that absorption and re -emitting takes microseconds) would simply join the upward flow of energy already flowing around co2. Even if there was a “supposed downwards flow of radiation” surely the lower co2 would just absorb that, why should it only absorb upwards flowing radiation at 15 microns, of course you would get the weird situation of perpetual motion as the energy flowed up and down between the co2.

    Harvard –
    “A low cloud, however, has a temperature close to that of the surface due to transport of heat by convection. As a result it radiates almost the same energy as the surface did before the cloud formed, and there is little greenhouse warming”

    So-
    Surely the limited co2 within this area would act in the same way.

    I see the only way for co2 to cause any warming is for it to actually form a layer like cloud in the atmosphere, but even then, if at the level of lower cloud you would get the same result as lower cloud above.

    If I look at the desert I see extreme heat cause by lack of moisture and at night extreme cold caused by lack of moisture.

    It feels as though there are two processes at work here proved by the desert , a cooling in the day caused by higher moisture content, after all we do not need greenhouse gases to cause extreme heat in the daytime – the moon, and at night a slowing down of heat loss until Sun up.

    So no extra warming up to the level of lower clouds for starters.

  163. Phil. says:

    DirkH says:
    April 11, 2014 at 5:17 pm
    Phil. says:
    April 11, 2014 at 12:21 pm
    “Kirchoff’s law doesn’t say what you think it does! It just says that emissivity equals absorptivity.”

    A distinction without a difference.

    Which only goes to prove that you don’t have a clue about the subject!

  164. MikeB says:

    aGrimm says:
    April 12, 2014 at 3:23 am

    The reference is to a previous comment in this thread, which you obviously haven’t followed. I gave the time so you should find it.

    Gyosperm is not referring to a broad spectrum of wavelengths. Again, if you had followed the comments you would know this. We are referring specifically to radiation at 15 microns. Do have reading difficulties?

    Of course visible light gets through. That’s how we see the Moon, the stars and the Sun.
    Forgive me, it gets frustrating when I say something absolutely right and you chip in with a load of rubbish without reading the comment thread first.

  165. Nullius in Verba says:

    “@ Mike B – I’m having troubles finding your Nullius reference; could you post the URL for it?”

    He means this one:
    http://wattsupwiththat.com/2014/04/11/methane-the-irrelevant-greenhouse-gas/#comment-1611098

    The ‘fogbank’ concept is just a simplified image to aid intuition. If you could see in infrared, the atmosphere would appear semi-transparent, like fog, so you could only see part way through it. The idea is that the visible ‘surface’ you see from above is what emits radiation to outer space, and it is this fuzzy ‘surface’ that settles at the -18 C average temperature needed for the Earth to emit as much energy as it absorbs.

    Perhaps it would be clearer using Venus as an example. Even in the visible spectrum, you cannot see the solid surface of Venus. It is shrouded in high-altitude clouds that look like a fuzzy opaque fog. The energy absorbed by Venus from the sun is all emitted by these cloud tops, and so it is the cloud tops that have to achieve energy balance with the outside universe. The temperatures there are actually pretty similar to Earth. But because the visible cloud surface is around 50 km above the solid surface, and the adiabatic lapse rate on Venus is about 8 C/km, there is a 400 C temperature difference maintained between the solid surface and the average altitude of emission to space.

    Carl Sagan wrote a short paper back in 1967 estimating the surface temperature of Venus by this method, before they were able to send probes there to measure it. ( http://adsabs.harvard.edu/full/1967ApJ…149..731S ) In a convective atmosphere, the surface temperature is the temperature needed to achieve energy balance plus the adiabatic lapse rate times the altitude of emission to space. Everything else going on below that point cancels out.

    Or if that still doesn’t convince, try working out the magnitude of the greenhouse effect in liquid water. Since water absorbs all thermal IR within about 20 microns, it acts as a super-intense ‘greenhouse fluid’. Sunlight shines through and is absorbed deep down, but then on re-radiating it is immediately absorbed and re-radiated and absorbed again. It’s fairly easy to calculate that if you only consider energy transport by radiation the temperature ought to be hundreds of degrees less than a metre below the surface.

    The reason the oceans don’t boil is that the difference between the level at which sunlight is absorbed and the emitting surface is only tens of metres, and the adiabatic lapse rate in water is only about 0.1 C/km, because water is incompressible. With a negligible near-zero adiabatic lapse rate, you get essentially no greenhouse warming, despite water being tens of thousands of times more intense a ‘greenhouse fluid’ than air. If the lapse rate was negative, then adding more greenhouse gases would result in cooling! (As happens in the stratosphere.) Try explaining that one using the other explanation!

  166. Phil. says:

    Alex says:
    April 11, 2014 at 8:34 pm
    Looking at transmission graphs can very deceptive. They say nothing about the energy of those absorptions/emissions. To get a realistic view they should be incorporated in an energy/wavelength graph -blackbody curve. Then you could see quite clearly how much energy is transmitted. Area under a curve. Transmission graphs don’t tell you if you are transmitting a creek or a mighty river of energy.

    REPLY: go ahead and work that up then, and we’ll add it as an addendum – Anthony

    Which is why I present the graphs as a plot of wavenumber which is proportional to the energy rather than wavelength which is inversely proportional to energy. See George’s post above too.

  167. richard says:

    Harvard –
    “A low cloud, however, has a temperature close to that of the surface due to transport of heat by convection. As a result it radiates almost the same energy as the surface did before the cloud formed, and there is little greenhouse warming”

    We have established that with or without the effect of the lower cloud there is no extra warming, this is the sun’s maximum output and heat within the range of the lower cloud so why should any other gases in the atmosphere have any other effect within this range ( up to lower cloud) .

    If there was an addition to the temp within this range from some kind of extra gas i want to know as i will fill my greenhouse with it and generate more energy from my thermal air pump.

  168. Nullius in Verba says:

    “If there was an addition to the temp within this range from some kind of extra gas i want to know as i will fill my greenhouse with it and generate more energy from my thermal air pump.”

    You don’t want to use a gas, you want to use a liquid. In fact, what you want is a solar pond.

    As I noted above, in a convective fluid, the adiabatic lapse rate dominates. But if you can suppress convection, then the ‘conventional’ radiative explanation tends to carry more weight. One way to do this is to fill a pond with water, but very carefully layer it so that at the bottom it is salt water, and at the top it is fresh. The saltwater is denser and the density gradient suppresses convection. This means the heat cannot escape from the bottom convectively, and because radiation is blocked by water being extremely opaque to IR, only conduction is left, which is very slow in still water. Solar ponds can routinely achieve temperatures of 90 C at the bottom of a couple of metres of water, (before convection starts up again).

    They work best in sunny countries, where they’re sometimes used as a variety of solar energy collector. As the efficiency of an energy source depends on the temperature difference, they’re pretty low grade. But it would indeed help with your thermal pump.

  169. richard says:

    Nullius in Verba says:
    April 12, 2014 at 5:45 am

    if i was building a house from scratch and had the grounds to do it i would without doubt go this route,

    Castle Howard in Yorkshire, UK , have had great results from this method.

  170. DirkH says:

    MikeB says:
    April 11, 2014 at 12:46 pm
    “Quite right Phil. But Dirk thinks it means that an object must emit as much radiation as it receives. He keeps saying this and no amount of correction will get him to think why that is obviously wrong.”

    Still no tropospheric hotspot. No heat trapping gases. Why does your stuff not work?

  171. Kristian says:

    Steve Fitzpatrick says, April 11, 2014 at 8:24 am:

    “The reason GHG’s reduce loss of heat to space is that absent GHG’s the surface would emit infrared photons directly to space (since the non-GHG’s in the atmosphere are essentially transparent in the infrared wavelengths), while space, with an effective temperature just above absolute zero, would emit essentially no photons back toward Earth.”

    Steve, you forget about one thing. The troposphere is primarily warmed through convective processes (conduction/convection/evaporation), not solely by radiation as you seem to think. Absent ‘GHGs’, the troposphere would still be warmed convectively. It could however NOT adequately cool to space. It would thus ‘trap’ the energy (heat) transferred to it from the surface.

    The so-called ‘GHGs’ do not enable the atmosphere to warm. It starts warming convectively as soon as it’s placed on top of a solar-heated surface. No, they enable it to cool, by ultimately radiating the acquired surface energy effectively to space.

  172. The post has it nearly correct for CH4 methane -its absorptivity in the atmosphere is so small to be unmeasurable see here http://cementafriend.wordpress.com/2011/10/14/methane-good-or-bad/. However, the article is wrong about CO2. The absorption of radiation by water vapor at all temperatures is much -much greater (at least 10 times) that of CO2 The author should look at Chapter 5 of Perry’s Chemical Engineering Handbook which has an equation to determine the absorptivity of mixed combustion gases. The equation was formulated from a vast amount of experimental data carried out in furnaces by Prof Hoyt Hottel of MIT. CO2 absorbs at wavelengths at 4.3 microns and at over a very small interval around 14.8micron. Water vapor has some absorption at all wavelengths but particularly from 5 to 8 micron and then again above 13 micron to well into the microwave range
    Engineers use real data, physicist seem to base their data on what suits their thought bubbles.

  173. Kristian says:

    Ron C. says, April 11, 2014 at 11:36 am:

    “3) Bulk gases of the atmosphere, O2 and N2, are warmed by conduction and convection from the surface. They also gain energy by collisions with IR active gases, some of that IR coming from the surface, and some aborbed directly from the sun. Latent heat from water is also added to the bulk gases. O2 and N2 are slow to shed all this heat, and indeed must pass it back to IR active gases at the top of the troposphere for radiation into space.

    This third pathway has a significant delay of cooling, and is the reason why our surface has the temperature it does.”

    Any sane person would understand, if they only took the time to think it through, that the delay in energy OUT from earth’s surface relative to energy IN (from the sun) lies in the convective process, not in the radiative. The first one needs to physically move massive air against gravity. The second one needs no such thing.

  174. Nullius in Verba says:

    “The troposphere is primarily warmed through convective processes (conduction/convection/evaporation), not solely by radiation as you seem to think.”

    Convection can only redistribute energy. It’s not a source.

    Sunlight warms the surface. The opacity of the atmosphere stops it radiating directly to space. Convection short-circuits the effect of the opacity, cancelling out its effect, but only up to the point where the adiabatic lapse rate is achieved. The ALR controls the surface temperature, but it isn’t the source of the energy.

    “Absent ‘GHGs’, the troposphere would still be warmed convectively.”

    Absent GHGs (but still with clouds), the effective altitude of emission to space would be zero, the surface would be at an average temperature of -18 C in order to radiate as much as was absorbed, and the troposphere would be even colder. The ALR would still cool it with altitude at the same rate, but starting from a lower base point.

  175. Kristian says:

    Nullius in Verba says, April 12, 2014 at 6:31 am:

    Nullius, you really wanna reopen this discussion …? With nonsensical statements like this: “The ALR controls the surface temperature (…)” you’re simply not one that can be taken seriously. It proves how you absolutely won’t understand the most basic rules of how the earth system works, how any surface/atmosphere system works. You are no skeptic, Nullius. You adhere to dogma. Try to think for yourself rather than just credulously echo all that the Masters of the Climate Religion enunciate to the world.

    How would the solar-heated surface of the earth be -18C with an atmosphere on top of it that could be heated through conduction/convection (with the energy (and thus the temperature profile) distributed upwards along the ALR up to the tropopause) but NOT adequately cool to space via radiation?

    Think, Nullius. Think.

  176. Uncle Gus says:

    MikeB – Which side are you on? Yes, CO2 is at saturation. That means that increasing it makes no difference. That’s an argument *against* CAGW.

    Leonard Weinstein – Yes that’s a very plausible theory. I’d take it more seriously if I’d heard it anywhere before Tom Sheahen posted this article. We’ve all seen this so many times; something threatens the original theory, so someone comes up with a totally different theory predicting the same result. Science is supposed to be about explanations, not predictions.

    Tom Sheahen – Like many here, I’m not totally convinced, but it does show up one thing; that the phrase “greenhouse gas” is a gross simplification, and that the situation is a lot more complicated than is popularily supposed.

  177. gymnosperm says:

    MikeB,

    How do we know the provenance of a photon? Emission can only occur at the given temperature for the wavelength. A quantum of energy from the surface could be absorbed and remitted many times on its way out, or it could pass straight through. It makes no difference. We are talking about the speed of light.

  178. MikeB says:

    Uncle Gus,
    Whose side are you on? It’s not a matter of taking sides I hope. It isn’t a football match. It would be nice to get the truth. In climate science there are things which are known (and which have been known for centuries) and it seems very stupid to contest those as some people here do.
    Having said that I think that the level of scientific debate on this site has improved recently. We still get the same stupid people making the same stupid comments of course but there seem to be more commentators who actually know something. Still in a minority, but growing.

    The sceptic cause is not helped by backing crackpot theories. There is no need for that. The science as we know it does not lead catastrophe, but you cannot argue that case if ignorance is your only weapon.

    Increasing CO2 will certainly make a difference or, as Professor Richard Lindzen (do you know who he is?) puts it, it should! The only question is how much?

  179. Nullius in Verba says:

    “How would the solar-heated surface of the earth be -18C with an atmosphere on top of it that could be heated through conduction/convection (with the energy (and thus the temperature profile) distributed upwards along the ALR up to the tropopause) but NOT adequately cool to space via radiation?”

    That’s easy. While the atmosphere cannot radiate to space, the surface can. It would warm or cool until the outgoing energy matched the incoming, which would be at -18 C.

    The air in contact with it would rise at the equator and cool adiabatically with altitude, but when it came down again at higher latitudes it would warm again at the same rate to its original temperature, transfer its heat to the surface by conduction, and the surface would radiate it to space. All the energy that entered the system would leave it, just as it does now, but it would all leave from ground level. The atmosphere would help spread it around horizontally, but its net effect on surface temperature would be zero.

    All of this I’ve independently figured out and checked for myself. But much of it was also previously developed in the 1960s, and constitutes the ‘mainstream’ mechanism used in the models, albeit with a different emphasis and slant to the usual ‘official’ explanations seen in universities. It’s perfectly orthodox, but I’m not accepting it just because it’s orthodox, but because on this occasion it happens to be correct, too.

    The issue with CAGW theory has never been to do with the GHE mechanism itself, but with the feedbacks. Getting the basic GHE physics wrong just makes it easier for the warmists to discredit us. I wouldn’t ever suggest that you give up on expressing alternatives that you think are correct simply because it sets back the cause of scepticism – we should always argue these things out. But it can be frustrating sometimes when the discussion keeps on going round in endless circles.

    I agree, we really don’t want to open up this discussion again. It annoys our host. So I’m happy to clarify things for people who are interested and want to understand something about it, but I’m not going to argue any further. I’ve said what I’ve said. It should be enough.

  180. Nullius in Verba says:

    “Leonard Weinstein – Yes that’s a very plausible theory. I’d take it more seriously if I’d heard it anywhere before Tom Sheahen posted this article.”

    You can find it in Soden and Held 2000 http://www.clidyn.ethz.ch/ese101/Papers/held00a.pdf See the discussion just above figure 1 on p446-447.

    You can also find it in the Sagan paper I linked above. And I explained it previously on Judith Curry’s site – see http://judithcurry.com/2010/12/02/best-of-the-greenhouse/ and scroll down to ‘radiative-convective perspective’. I know Leonard has engaged in extensive discussions about it over at ScienceOfDoom – I’m sure he can point you to some of them.

  181. richard says:

    Nullius in Verba

    Alarmism has worked in one way, the 30 year endless repetition that co2 causes warming.

    This has to be countered again and again until the knuckles bleed, the following- below, but in some way that is easy to digest for the average person- me! so easy that newspapers can print it, in some visual form, there are some papers that would use it.

    http://acmg.seas.harvard.edu/p
    In order to maintain a constant terrestrial blackbody emission integrated over all wavelengths, it would be necessary to increase the emission flux in other regions of the spectrum and thus warm the Earth. Contrast this situation to a greenhouse gas absorbing solely at 15 mm, in the CO2 absorption band ( Figure 7-8 ). At that wavelength the atmospheric column is already opaque ( Figure 7-13 ), and injecting an additional atmospheric absorber has NO significant greenhouse effect.

  182. Nullius in Verba says:

    “Alarmism has worked in one way, the 30 year endless repetition that co2 causes warming.”

    Alarmism works by setting up a decoy position for you to waste your time attacking. The question is not, and never has been, whether CO2 causes warming. It has always been whether it causes enough warming to be a problem.

    Alarmists like to pretend that once you accept the basic physics of the GHE, that all the disaster predictions follow as an inevitable consequence. It would be like people predicting a catastrophic asteroid impact follows from the law of gravity – there are rocks in the sky, they’re heavy, they fall down. You can’t win that argument by trying to claim that gravity doesn’t exist!

    Don’t fall into the trap of assuming that just because they say that “CO2 causes warming therefore we must panic”, that this is so. Yes, CO2 causes warming. No, we don’t need to panic. If you waste your time in a fruitless attempt to prove CO2 doesn’t cause warming, and burn your own credibility in the process, they’ll be able to get away with the other, flawed part of their argument scot free.

  183. DirkH says:

    MikeB says:
    April 12, 2014 at 7:55 am
    “Having said that I think that the level of scientific debate on this site has improved recently. We still get the same stupid people making the same stupid comments of course but there seem to be more commentators who actually know something. Still in a minority, but growing.”

    MikeB and Phil.; it looks like you are right and I was wrong. BUT now I have a question. It’s a serious one. Really.

    How can there be talk of downwelling IR in the CO2 absorption spectrum IF the mean free path length at surface pressure is about 30m or so AND the probability of photon absorption and thermalization is WAY higher than the probability of dethermalization and photon emission? All these photons should vanish after a few dozen meters.

  184. richard says:

    Personally i think you have to put a cap on how much warming according to physics.

    “Contrast this situation to a greenhouse gas absorbing solely at 15 mm, in the CO2 absorption band ( Figure 7-8 ). At that wavelength the atmospheric column is already opaque ( Figure 7-13 ), and injecting an additional atmospheric absorber has NO significant greenhouse effect”

    To continue with this –
    “It has always been whether it causes enough warming to be a problem”

    and

    “Yes, CO2 causes warming” is just a festering wound and will never be answered and the alarmism will continue for ever. The temps just have to rise again one day and just wait for the barrage of MSM on that one, it will be incessant.

  185. Steve Case says:

    Nullius in Verba said at 8:59 AM

    Alarmism works by setting up a decoy position for you to waste your time attacking. The question is not, and never has been, whether CO2 causes warming. It has always been whether it causes enough warming to be a problem.

    Alarmists like to pretend that once you accept the basic physics of the GHE, that all the disaster predictions follow as an inevitable consequence. It would be like people predicting a catastrophic asteroid impact follows from the law of gravity – there are rocks in the sky, they’re heavy, they fall down. You can’t win that argument by trying to claim that gravity doesn’t exist!

    Don’t fall into the trap of assuming that just because they say that “CO2 causes warming therefore we must panic”, that this is so. Yes, CO2 causes warming. No, we don’t need to panic. If you waste your time in a fruitless attempt to prove CO2 doesn’t cause warming, and burn your own credibility in the process, they’ll be able to get away with the other, flawed part of their argument scot free.

         B I N G O !

  186. Kristian says:

    Nullius in Verba says, April 12, 2014 at 7:58 am:

    “While the atmosphere cannot radiate to space, the surface can. It would warm or cool until the outgoing energy matched the incoming, which would be at -18 C.

    The air in contact with it would rise at the equator and cool adiabatically with altitude, but when it came down again at higher latitudes it would warm again at the same rate to its original temperature, transfer its heat to the surface by conduction, and the surface would radiate it to space.”

    Er, no, Nullius. The energy conducted/convected from the surface to the atmosphere would never be able to just as easily conduct/convect back down. Are you being serious?! This is the same nonsense that Stephen Wilde is promulgating on the ‘Correcting Trenberth et al.’ thread. What kind of bubble world are you living in?

    The atmosphere (and hence the surface) would of course be much hotter WITHOUT radiatively active gases there to cool the system to space than WITH. The surface can’t cool adequately to space through radiation with an atmosphere present on top of it, because too much of the incoming energy is lost through conduction/convection to the atmosphere: If 2 parts of energy comes in from the sun to the surface and 1 part goes out to the atmosphere via convective processes, how many parts of energy do the surface have left to radiate out to space? The surface (and hence the system as a whole) could of course never reach proper radiative balance between incoming and outgoing with an atmosphere without the ability to adequately cool to space, because the atmosphere could receive heat from the surface, but not efficiently transfer it out and away.

    The so-called ‘GHGs’ do not enable the atmosphere to warm, Nullius. It would’ve with or without them. They enable it to cool efficiently to space. That’s what they do.

  187. Kristian says:

    Nullius in Verba says, April 12, 2014 at 7:58 am:

    <em"The issue with CAGW theory has never been to do with the GHE mechanism itself, but with the feedbacks."

    Exactly. And that’s precisely why they can perpetuate their myth that CO2 warms the earth system with you ‘CAGW skeptics’ as their useful idiots. The proposed ‘GHE mechanism’ is pseudoscientific nonsense, but as long as you defend it with your life, we will never get rid of the festering boil that is the CAGW hype. The hypothesis of CAGW builds upon the hypothesis of AGW that in turn builds upon the hypothesis of the GHE. The latter one is what engendered the warped physics that created the basis for the other two. The two former ones actually by themselves have more going for them, they’re more based on real physics than the former one. The only reason they won’t work is that they build upon the self-construed physics of the apparently sacred ‘GHE hypothesis’.

  188. Steve Fitzpatrick says:

    Nullius in Verba,

    One little nitpick: Over much of the ocean there is thermally driven convection only near the surface (in the well mixed layer) because slow continuous upwelling of cold deep water keeps the sunlight which is absorbed below the WML from warming the deeper water to above the surface temperature. Absent the transport of cold water from high latitudes to low near the ocean floor, at low latitudes the ocean would become pretty uniform in temperature to great depth.

    You are exactly correct (April 12, 2014 at 8:59 am); claiming higher concentrations of GHG’s do not cause warming just means you instantly lose the argument about catastrophic warming, because people will ignore everything you say after that. Arguing higher GHG concentrations do not cause warming only makes most technically trained people think you are either uneducated, stupid, or crazy. The real technical argument has never been about GHG driven warming, it has always been about the accuracy of ‘amplification’ of GHG driven warming to catastrophic levels. Winning the technical argument that catastrophic warming is extremely unlikely is relatively easy…. you have the data (AKA reality) on your side, while your opponents have mainly climate models…. which are both demonstrably wrong and so full of kludges and doubtful assumptions that their temperature projections are risible. If the technical argument is about the plausibility of catastrophic temperature increases, then the Mathusian-eco-loons (many of whom are, sadly, ‘outspoken climate scientists’) will lose the public policy argument to force drastic immediate reductions in fossil fuel use. And that is only argument which really matters.

    One suggestion: There are some people who will forever refuse to be convinced that GHG’s can possibly cause warming. There are some people who will forever refuse to accept that burning fossil fuels causes atmospheric CO2 to increase. There are some people who will forever think radiative physics is fundamentally wrong… and others who will forever hold many other factually incorrect (even bizarre!) beliefs. IMO, once this situation becomes clear, it is a waste of time to engage any of these folks.

  189. Nullius in Verba says:

    “One little nitpick: Over much of the ocean there is thermally driven convection only near the surface (in the well mixed layer) because slow continuous upwelling of cold deep water…”

    :-) One little nitpick back – what causes that slow continuous upwelling? Isn’t it the pole-to-equator global convection cycle?

    It’s actually a cute example – I was going to mention it earlier and then decided it was getting too complicated. The oceans are actually a pretty neat analogy for what would happen with a non-GHG atmosphere, only inverted – with the roles of heating and cooling, rising and falling, equator and poles swapped around. The deep water formation near the poles is analogous to the heating of a non-GHG atmosphere near the equator. The water descends into the deep like the air rises into the troposphere. With no way to gain or lose heat, the temperature then varies only adiabatically until it cycles round to the other end, where the water warms at the equator or the air cools at the poles, and flows across the surface to begin the cycle anew.

    But given the difficulty I was having explaining the straightforward physics, I thought this inverted analogy would just cause people’s brains to explode. Nevertheless, and with a health warning, I offer it up now to anyone who wants to think a little more deeply about this stuff. If you didn’t follow what I said earlier, don’t bother with it. It’s not important.

  190. richard says:

    “The atmosphere (and hence the surface) would of course be much hotter WITHOUT radiatively active gases there to cool the system to space than WITH”

    I know in the Desert in the daytime it leads to hotter, but at night?

  191. Ron C. says:

    richard says:
    April 12, 2014 at 1:56 pm

    At night in the desert, you can see how rapidly CO2 (no H2O) is able to cool things down.

  192. Rob says:

    This was informative because of the problems with the post, leaving lots of room for comments to provide more accurate information. I don’t know how the whole thing works though. I know that theory says the poles should have a much stronger warming effect from GHG’s since water vapour is hardly present there. This should mean that there is a strong masking effect where water vapour dominates the effect of anything else on its absorption bands. Yet the description of each molecule having its own slowing effect on heat cannot jive with that. I’m assuming that the masking effect is at least mostly valid, if not there would be no reason for anyone to have thought that the tropics are less affected. If that’s just wrong it’s pretty stunning, although it would help out warmers (a little) with their south pole problem.

  193. Ron C. says:

    Rob, I was just having a bit of fun with Richard.

    The real deal is that after the desert broils in the sun all day, the accumulated heat is rapidly convected away. CO2 in the absence of H2O is utterly powerless to stop it.

    The Moral: In the lower troposphere, convection rules. In the upper troposphere, radiation matters.

  194. Dr. Strangelove says:

    Dr. Tom Sheahen

    Check the optical length and gas concentration used in your chart. Let’s assume it uses a standard 1 m length. The bandwidth of methane is from 2.5 to 8.5 um with peaks at 3.5 and 7.5 um. Note the low absorption values are not zero. It means methane is absorbing IR in the entire bandwidth. Let’s say the low value is 1% and the peak is 90%. That means after IR passes 1 meter of a gas with X% methane, 90% of 3.5 and 7.5 um IR will be absorbed and 1% for the rest of the bandwidth. Of course after passing 100 m the entire bandwidth will be 100% absorbed. And the troposphere is 10,000 m thick.

    There is no such thing as saturated bandwidth. This will only happen if you ran out of photons to absorb and this will not happen because the absorbing gas molecules also emit the photons at the same wavelengths. The photons do not disappear in the atmosphere. You can check in TOA satellite data if 7.5 um IR is missing hence it is already “saturated.” It’s like saying bucket A can no longer scoop water in the well because bucket B is already full. Ten buckets can be full and you can still scoop water as long as there’s still water in the well.

  195. Latitude says:

    Steve Fitzpatrick says:
    April 12, 2014 at 10:30 am
    One suggestion: There are some people who will forever refuse to be convinced that GHG’s can possibly cause warming. There are some people who will forever refuse to accept that burning fossil fuels causes atmospheric CO2 to increase.
    =====
    Just as there are people that use GHG’s and CO2 as if they are the same
    ….it is a waste of time to engage any of these folks.

  196. gofigure560 says:

    Is there any meaning/accuracy to a claim I came across several years ago, based on the fact that there are only a few sun energy bandwidths available for co2 to “absorb” and at 20ppmv it had already absorbed 50% of all the energy available to it. Of course, now at 400 ppmv it would seem there’s little left. This would explain why when co2 was at higher levels it seemed to have no impact on global temperature. Is that claim accurate? meaningful?

  197. bushbunny says:

    Desertvoke, explanation accepted. However, folks, methane is created by waste dumps, decomposing vegetable matter, and people use it to drive electricity in bush areas, using pooh.
    Thermal solar are also exploring using methane to generate electricity at night.

    Do you think that is why Parchari said once, if we became vegan or vegetarian this would help change the climate because of less methane? Sheep and goats also produce methane, all ruminants. I don’t think elephants are ruminants, but they deposit lots of manure.

    Peat bogs create some gas, not sure if it is methane.

    Why deserts get very cold at night is because there is no cloud cover.

    They are grasping at straws, rehashing their science. Forget it, and enjoy your beef and lamb, goat, preferably free range not from feed lots. If feed lot animals are not fed the right balanced dry food diet, they are high in Omega 6 and not Omega 3.

  198. Patrick says:

    “bushbunny says:

    April 12, 2014 at 7:07 pm”

    Largest sources of methane include wetlands (That would include peat bogs and swamps etc, hense the term “swamp gas”), rice fields, plants including healthy forests and termites to name several others outside the alarmist claims that we humans contribute the most. The current concentartion of CH4 at ~1.8ppm/v would make it near impossible to separate the human contribution. CH4 at waste dumps is usually burnt off to form CO2. I know that back in the 1980’s I worked at IBM, Havant Plant, near Portsmouth, England. Next door was a sewage treatment plant. IBM made a deal with the local council to have methane pupmed in to provide fuel for heating. Saved IBM millions of pounds on heating costs.

  199. bushbunny says:

    Thank you Patrick, I didn’t put references down to prove my point, because I know it is common knowledge. Of course methane also collects in mines too. That’s why miners, kept canaries in cages, and if they fell off their perches, they knew some gas was around. Methane is with nitrous oxide a trace gas in the air we breathe. Our university was given a grant to find out how to remove nitrous oxide from soils. I was studying my diploma in organic agricultural production at the time, and our lecturer said, “I can tell them how to get rid of it easily, add gypsum” I do think that sometimes you ask the farmers. From what I can remember, nitrous oxide is also laughing gas, and can be toxic to plants and is created by too much vegetable matter and decay in wet soils. Gypsum breaks up clay and aerates the soil. “If they would give me 250,000 dollars I could tell them that, it is common knowledge” said our lecturer.

  200. george e. smith says:

    A number of posters up above reference Kirchoff’s law relating to absorption and emission of EM radiant energy.
    It’s almost 60 years since I studied such things, but as I recall, the law applies to thermodynamic systems where an EM radiation field is in thermodynamic equilibrium with a physical medium, which is capable of exchanging energy between the medium, and the radiation field, at ANY possible frequency.

    At thermal equilibrium, the spectral radiant emittance and the spectral radiant absorptance must be equal at each and every frequency present in the radiation field. It is not any integrated total energy exchange, it is a point by point match. And that implies that the medium is able to facilitate the movement of energy from one radiating frequency to another until they all are in balance.

    That almost guarantees, that the radiation field must be a thermal radiation field, where the radiation spectrum, is a consequence of the equilibrium Temperature (which must be uniform throughout the system).

    So it is highly unlikely, that Kirchoff’s law, can be applied to the case of absorption and emission of atomic or molecular resonant radiation frequencies, such as the GHG molecules. They are not capable of transmuting some photon energy into any arbitrary frequency present in some thermal radiation spectrum.

    The “band” spectra of molecules and the line spectra of atoms, do not follow the same rules as the continuum spectra of thermal radiation such as black body spectra. In the case of atomic line spectra, some transitions from an excited state to a lower state are forbidden by selection rules, or are of much lower probability as a result. The excited state population inversions necessary for the operation of many laser systems, are a consequence of such restrictions.

    Many sources of energy operate to warm the atmosphere; but it is what happens subsequently to that extra energy that is of interest for weather and the climate. In particular it can’t appreciably warm the ground; but additional sunlight energy that enters during the delayed exit of the LWIR, can. And the clouds will adjust to negate almost all of it.

  201. Patrick says:

    “bushbunny says:

    April 12, 2014 at 7:45 pm”

    It maybe common knowledge to the likes of you and I and others here at WUWT but MOST people have no clue. During a heated debate about climate change one lunch time at work last week a workmate was prattling on about how GHG’s trap heat in the atmosphere. I then asked him, as I did my other friend a week or so ago, how much CO2 he thought was in the air. He thought about it for a short while and then replied “About 50%.” He had no idea that N2 was at ~78% an O2 was at ~21% of the air we breathe and that CO2 was actually ~0.0395% to which he found at odds with what the MSM was telling him.

    Sadly, and I am sure you will agree, the Aussie MSM has done a spectacularly good job of spreading misinformation about “carbon pollution”.

  202. bushbunny says:

    Patrick, Yes, I had the same argument too, months ago with some troll, obviously young I felt. Enough carbon dioxide will kill you he reckoned. If one is shut up in a closed air tight room. Too little oxygen will kill you for sure, and carbon monoxide. But when I asked what were the proportions of gases that we normally breathe, he replied, ‘You tell me!” My son, a born again hippie and green, the youngest one, not the eldest, said the same. I replied, ‘Daarlink, 95% of Greenhouse gases is water vapor. We need it. They form those little fluffy things in the sky” If we didn’t have CO2 to breathe we’d be dead. Didn’t believe me of course.

    I suspect it is easier to fool people than convince them they have been fooled. The thing is, nature has a way of balancing things, usually in her/him’s favor. On the one side we have the realists, and on the other – the political and naive greens who look at rainbows and think how lovely they are but don’t know what or how they are created.

  203. bushbunny says:

    Just on an end note, that scare about diminishing polar bears and ice. I suppose they don’t know, that male bears will kill and eat polar bear cubs, if they get a chance. And that they do hibernate like other bears too.

  204. richard says:

    Ron C. says:
    April 12, 2014 at 4:39 pm
    Rob, I was just having a bit of fun with Richard.

    The real deal is that after the desert broils in the sun all day, the accumulated heat is rapidly convected away

    ————————————-

    I don’t understand this , there is little moisture in the desert and yet the heat rapidly decreases.

    “So, its clear that convection requires a medium (specifically, a non-solid medium). Unlike radiation, if there is no medium near the source, it cannot loose its heat simply using convection. (It can of course loose it via radiation.)

  205. richard says:

    Convection or radiation

    or is there enough moisture to rapidly convect away the heat.

  206. richard says:

    but if convection requires a non solid medium – ie- moisture is the key for convection, you would assume the tropics on a cloudless night with more moisture content would cool rapidly.

  207. richard says:

    Ron C. says:
    April 12, 2014 at 4:39 pm
    Rob, I was just having a bit of fun with Richard.

    The real deal is that after the desert broils in the sun all day, the accumulated heat is rapidly convected away. CO2 in the absence of H2O is utterly powerless to stop it.

    The Moral: In the lower troposphere, convection rules. In the upper troposphere, radiation matters.

    ————————————
    Damn, I am none the wiser

    http://www.erc.uct.ac.za/jesa/volume16/16-2jesa-dobson.pdf

    1. Introduction
    When a surface on the earth faces the night sky, it
    loses heat by radiation to the sky, and gains heat
    from the surrounding air by convection. If the surface is a relatively good emitter of radiation, it will
    tend to radiate more heat to the sky at night than it
    gains from the air. The net result is that the surface
    temperature drops to below that of the air. This
    phenomenon is termed night sky radiation cooling.

  208. Ron C. says:

    Richard, the air is the medium for convection. Block the air, as in a greenhouse, and convection stops, the heat stays put. Moisture is not needed, except for evaporative cooling.

    Your link is to a paper on designing a radiator device that would cool even faster than convection.

  209. richard says:

    Richard, the air is the medium for convection,

    so where the air becomes thinner in the upper troposphere it changes to Radiation.

    Fine with that,

    so we find that lack of moisture heats the desert quickly in the daytime and without it the desert cools rapidly at night,

    Well obviously apart from deserts near the sea where the higher moisture allows it to stay fairly hot at night.

  210. Uncle Gus says:

    Mike B –

    I didn’t mean to get your goat. Like you, I’m not convinced by Sheahen’s argument. I really couldn’t make out if you were attacking it from a warmist of a sceptic perspective. You’re quite right, it shouldn’t make a difference, but it helps to know if someone is going to blast the top of your head off for doubting CAGW.

    Of course, if I followed this blog more often I’d have remembered seeing you before. Mia culpa!

  211. TomP says:

    Sorry to have to tell you guys but Tom Sheahen’s knowledge of atmospheric physics is about 100 years out of date. Maybe he should take a refresher course.

  212. Willis Eschenbach says:

    TomP says:
    April 13, 2014 at 2:55 pm

    Sorry to have to tell you guys but Tom Sheahen’s knowledge of atmospheric physics is about 100 years out of date. Maybe he should take a refresher course.

    Sorry to have to tell you, but some random anonymous internet jumpup like yourself making extravagant claims about someone you’ve never met, without presenting a scrap of evidence to back up your big mouth, should take a refresher course in how to present and support an idea …

    w.

  213. bushbunny says:

    Oh dear willis, we are not at university compiling a paper on this subject.

  214. bushbunny says:

    Tom’s paper is right, that’s what I learned during my studies for my diploma in organic agricultural
    production. How can it be 100 years out of date, mate? Change ruminants digestive system, they won’t like that, they will die.

  215. Willis Eschenbach says:

    bushbunny says:
    April 13, 2014 at 11:31 pm

    Oh dear willis, we are not at university compiling a paper on this subject.

    I assume you are referring to something I said … but I have no idea what I said that has set you off. And I can’t be bothered to search it out, that’s a mug’s game.

    Nor does anyone else know what you are talking about. Oh, they may think they know … but then they might or might not be right.

    If you don’t quote what has your knickers in such a twist, how is anyone supposed to be clear about what you are going on about?

    w.

  216. TomP says:

    Willis, the reason why Sheanen’s argument is wrong is that he fails to mention that the water vapor is limited to the lower troposphere by the temperature gradient. CH4 and CO2 are not. At the top of the troposphere the concentration of WV drops to the point where other GHGs are determining the escape of radiation. That’s why his claim that “the effects of CH4 are completely masked by H2O” is a straightforward flasehood. Either he doesn’t understand the physics involved, or he is being worse than disingenuous.
    I’m glad to see that you know how to use MODTRAN. If you play around a bit more, you’ll find that doubling CH4 has about the same effect as increasing CO2 by around 50ppm. That is what is meant by the statement that CH4 is a potent greenhouse gas.

  217. Patrick says:

    “TomP says:

    April 14, 2014 at 3:23 am

    If you play around a bit more, you’ll find that doubling CH4 has about the same effect as increasing CO2 by around 50ppm. That is what is meant by the statement that CH4 is a potent greenhouse gas.”

    Equivalent to a 50ppm/v increase in CO2 on top of current concentrations? So, almost nothing in terms GHG “warming” via proven physics?

  218. Trevor says:

    Dr. Tom:

    Someone else may have pointed this out, but I don’t feel like looking through 219 responses to find it, so here goes. Looking at the absorption cross-section graph, it appears to me that 3.3-micron band for methane is not “narrow” at all, not compared to most of the other bands for other gases. Though the peak is not as “clean” as others, it appears that methane absorbs SOME infrared radiation over a range of from about 3.0 microns to about 3.8 microns. And in the upper end of that range, from about 3.6 to 3.8 microns, water vapor’s absorption is ZERO. Not only that, but none of the other GHGs absorb ANY infrared radiation between 3.6 and 3.8 microns. Granted, methane absorbs only 20-30% of IR in that portion of that band, and assuming (I highly doubt this is a valid assumption, but it’s all I have at this time) that the actual emissions of IR are evenly spread across the 1-16 micron range, then the .2-micron width of this methane-exclusive absorption range amounts to just 1.3% of all IR, and at 25%, methane, will absorb, at a maximum (full saturation) just 0.3% of all IR over and above what is or would have been absorbed by other GHGs. That’s just back-of-the-napkin calculations, and a more accurate calculation (including the actual distribution of IR emissions across the entire 1-16 micron spectrum) will likely result a different percentage. I’ll leave that calculation (and the analysis of whether that percentage, whatever it turns out to be, is “significant”) to people who know more about this than me. But if there is ANY IR emitted in the 3.6-3.8-micron range, then I don’t think it’s accurate to say that water vapor absorbs ALL the IR that methane might absorb.

  219. Phil. says:

    george e. smith says:
    April 11, 2014 at 7:48 am
    Well expect a small nuclear explosion from Phil pretty soon.

    While I tend to discount the threat of CH4, as overblown (it’s another nice fuel we can use) the picture is not as simple as Tom depicts.

    But for starters, look at that CH4 band at 3.3 microns; also the CO2 band at 4.xx microns.

    Those we can discard completely, as no threat; in fact they are beneficial from a MMGWCCC point of view, because the only source of any 4 micron or less radiation, is the sun itself, and any atmospheric absorption of sunlight is a global cooling effect.

    But back to that 7.7 or so micron CH4 band overlaid by H2O.

    Well Tom’s graphs are very low resolution transmission spectra, and those “bands” are actually groups of very many much narrower spectral “lines” and there is no assurance that some water line overlaps some methane line, so the fact that the bands overlap, is no assurance that the individual lines do.

    The single molecule lines are in fact quite narrow, being resonances of a very precise structure. Those are then broadened as a result of inter-molecular collisions, giving Temperature broadening due to the Doppler effect, and the motion of the absorbing molecule; and also pressure broadening (actually density) due to the numbers of collisions.

    Even so, the broadened lines at the modest atmospheric T&P are still quite narrow, and line overlaps are not going to be as Tom’s band transmissions assert.

    But Phil, can do the honors. That ozone band at 9.6 microns is actually right in the middle of the so-called atmospheric window, so I’m not sure Tom’s water bands are correctly depicted.

    Water is a great LWIR absorber though.

    OK George, you are indeed correct that for the spectra to interfere the lines need to match. As you point out the low resolution spectra tell us nothing about that and the OP is misleading in this regard when he says:
    “Moreover, both of its bands occur at wavelengths where H2O is already absorbing substantially. Hence, any radiation that CH4 might absorb has already been absorbed by H2O. The ratio of the percentages of water to methane is such that the effects of CH4 are completely masked by H2O.”

    This statement is false, in fact the H2O lines are widely separated and are significantly outnumbered by the CH4 lines. For example between 7.4 microns and 7.41 microns there are approximately 300 CH4 lines and only about 10 H2O lines!

  220. t control says:

    How much has the permafrost actually melted so far?

  221. Ron C. says:

    The permafrost bogeyman disappears in the light of the facts.

    1) When there was warming in places like Alaska, atmospheric methane did not increase.

    2) Permafrost depletion in the NH stopped since 2005.

    3) When permafrost thaws, vegetation grows and removes more CO2 than is released by the melting. The region acts as a sink, not a source of CO2.

    4) Past warm periods (Medieval and Holocene warmings) did not produce increases in methane.Runaway warming from permafrost thawing has not happened before, is not happening now, but we should believe it will happen if we don’t do something?

    So the IPCC is stirring up alarm about thawing of Siberian permafrost. But there are scientists in Siberia monitoring the situation. What do they say?

    “Indeed above at the surface it has gotten warmer, but that’s just part of a normal cycle. The permafrost is rock hard, And that is how it is going to stay. There’s no talk of thawing.” Michali Grigoryev
    http://notrickszone.com/2012/11/19/russian-arctic-scientist-permafrost-changes-due-to-natural-factors-its-going-to-be-colder/

    “It seems that the permafrost should be melting if the temperature is rising. However, many areas are witnessing the opposite. The average annual temperature is getting higher, but the permafrost remains and has even started to spread. Why? An important factor is the snow cover. Global warming reduces it, therefore making the heat insulator for the permafrost thinner. Then even weak frosts are enough to freeze the ground deeper below the surface.”

    Nikolai Osokin is a glaciologist at the Institute of Geography, the Russian Academy of Sciences.

    http://en.rian.ru/analysis/20070323/62485608.html

    “The Russian Academy of Sciences has found that the annual temperature of soils (with seasonable variations) has been remaining stable despite the increased average annual air temperature caused by climate change. If anything, the depth of seasonal melting has decreased slightly.”

    “This is just another scare story . . . This ecological structure is balanced and is not about to harm people with gas discharges.”

    Vladimir Melnikov is the director of the world’s only Institute of the Earth’s Cryosphere. The Russian Academy of Sciences’ Institute is located in the Siberian city of Tyumen and investigates the ways in which ground water becomes ice and permafrost.

    “The boundaries of the Russian permafrost zone remain virtually unchanged. At the same time, the permafrost is several hundred meters deep. For methane, other gases and hydrates to escape to the surface, it would have to melt at tremendous depths, which is impossible.”
    Yuri Izrael, director of the Institute of Climatology and Ecology of the Russian Academy of Sciences.

    http://en.rian.ru/analysis/20050822/41201605-print.html

  222. t control says:

    Ron C. says:
    April 14, 2014 at 8:12 am

    thank you. That’s exactly the stuff I was looking for.

  223. Willis Eschenbach says:

    TomP says:
    April 14, 2014 at 3:23 am

    Willis, the reason why Sheanen’s argument is wrong is that he fails to mention that the water vapor is limited to the lower troposphere by the temperature gradient. CH4 and CO2 are not. At the top of the troposphere the concentration of WV drops to the point where other GHGs are determining the escape of radiation. That’s why his claim that “the effects of CH4 are completely masked by H2O” is a straightforward flasehood. Either he doesn’t understand the physics involved, or he is being worse than disingenuous.

    TomP, the moment you accuse a man you don’t know of being a liar, or either a liar or a fool, both of which you just did, I’m afraid you lose 97% of your credibility. In my experience, such accusations involving motive almost invariably come from a man who is very unsure of his science. If he were sure of his science, there’d be no need for accusations of malfeasance. So as a tactical matter, you’ve already lost the battle, even though you may be right … but you’re not. See below.

    I’m glad to see that you know how to use MODTRAN. If you play around a bit more, you’ll find that doubling CH4 has about the same effect as increasing CO2 by around 50ppm. That is what is meant by the statement that CH4 is a potent greenhouse gas.

    If increasing methane by 100% produces the same results as increasing CO2 by ~ 16%, I’d call it a weak GHG …

    Next, while it is true that at the top of the troposphere there is little water vapor, there is also little gas of any kind. As you most condescendingly say, I’m glad to see that YOU know how to use Modtran. And if you “play around” with it a bit more, in your unpleasant terminology, you will find that indeed, as you say the H20 levels drop much faster with altitude than do the CH4 levels. Most of the water vapor is near the ground.

    But what you obviously didn’t stick around to notice were the absolute levels. Lets take clear-sky tropics as the example. At ground level, the concentration of atmospheric water vapor is about 15,500 times that of methane.

    But even at 17 km elevation, the approximate height of the tropopause, there is still almost twice as much water vapor as methane. So your claim above is simply incorrect. Water vapor is indeed pretty trivial at the tropopause … but methane is even more trivial.

    So … should I now accuse you of “a straightforward falsehood”, and say you might be being “worse than disingenuous”? Heck, no. You just didn’t do your homework, happens all the time, to you, me and everyone.

    But your accusations of the same thing against the author? Not only were they over the top, because the worst that you can really say is IF your accusations were true, Dr. Seagal didn’t do his homework … but in fact YOU were the one who hadn’t done your homework.

    So in addition to being unpleasant, your accusations were simply untrue … and as a result, your own credibility has gone in the dumper.

    w.

  224. Willis Eschenbach says:

    Trevor says:
    April 14, 2014 at 6:30 am

    But if there is ANY IR emitted in the 3.6-3.8-micron range, then I don’t think it’s accurate to say that water vapor absorbs ALL the IR that methane might absorb.

    Trevor, this is why I ask people to QUOTE what they object to. I don’t see anywhere that Dr. Seagal said that “water vapor absorbs ALL the IR that methane might absorb”, or anything like that. In fact, he specifically states that methane has an effect, but that the effect of methane is only about 1% of the effect of water vapor, viz:

    The amount of CH4 must increase 100-fold to make it comparable to H2O.

    So … you’re attacking something he didn’t say. We all know, including Dr. Seagal, that methane has some effect. The question is the amount.

    w.

  225. Ron C. says:

    t control says:
    April 14, 2014 at 9:52 am

    Glad I had the info available. It was a search I did the last time the UN came with this scare, at Doha COP 18.

    At least they do their recycling.

  226. A chemist says:

    According to “Environmental Chemistry, a global perspective 3rd ed.”, Gary W. vanLoon and Stephen J. Duffy, Oxford University Press, a college level chemistry textbook, “The small concentration of methane would have little effect on Earth’s energy balance if it absorbed radiation within the major absorption bands of water or carbon dioxide. Methane, however, absorbs in the ranges from 3.0-3.6 um and 7.1-8.3 um, the latter lying in the window region noted above [region where water and carbon dioxide do not significantly absorb]“.

    Additionally, the most recent IPCC report state that emissions of methane alone have cause radiative forcing of 0.97 watts per meter squared – think of this as the additional energy for each meter squared due to methane. While this is certainly lower than carbon dioxide (1.68 watts per meter squared), it is still significant.

  227. Dr. Strangelove says:

    The global warming potential of methane is estimated to be 62x greater than CO2 by weight over 20 years. However, the lifetime of methane is only 12 years so it has no long-term effect on climate. There is very little methane in the atmosphere, only 1/200 the amount of CO2. It contributes less than 10% to the greenhouse effect compared to 60% by water vapor and 25% by CO2.

  228. bushbunny says:

    Willis, I object to your manner and the way you are rude and dismissive to anyone who has annoyed you or doesn’t agree with you. There is a sense, to me anyway, of arrogance and impatience. I had a lecturer like you at uni, who put down students with personal remarks without really addressing the question put to him. Dare anyone who didn’t reference anything in a quote or paragraph. Personal observations were not appropriate to him, one had to follow his thoughts on a subject and not argue that there were alternative view points that they did reference of course.

  229. Dr. Strangelove says:

    George smith

    “So it is highly unlikely, that Kirchoff’s law, can be applied to the case of absorption and emission of atomic or molecular resonant radiation frequencies, such as the GHG molecules. They are not capable of transmuting some photon energy into any arbitrary frequency present in some thermal radiation spectrum.”

    Kirchhoff’s law applies to GHG molecules. They follow Planck’s law that determines the spectral distribution as a function of wavelength and temperature.

    “The “band” spectra of molecules and the line spectra of atoms, do not follow the same rules as the continuum spectra of thermal radiation such as black body spectra.”

    Atoms and molecules are considered as gray body. They follow the blackbody spectra but reduced by their emissivity less than 1. The shape of the curve is the same but the area is smaller. All bodies are gray since there is no perfect blackbody.

  230. Willis Eschenbach says:

    bushbunny says:
    April 14, 2014 at 7:44 pm

    Willis, I object to your manner and the way you are rude and dismissive to anyone who has annoyed you or doesn’t agree with you. There is a sense, to me anyway, of arrogance and impatience. I had a lecturer like you at uni, who put down students with personal remarks without really addressing the question put to him. Dare anyone who didn’t reference anything in a quote or paragraph. Personal observations were not appropriate to him, one had to follow his thoughts on a subject and not argue that there were alternative view points that they did reference of course.

    If you can’t stand the heat, bushbunny, then get out of the kitchen. I’m not asking anything of anyone that I’m not asking of myself. I quote what others say so you and others can understand my objections, and I insist that others do the same. I provide the code and data and citations and observations and the math to support my positions, and I insist that others do the same. So sue me.

    You, on the other hand, say without any further details:

    Oh dear willis, we are not at university compiling a paper on this subject.

    That doesn’t give me or anyone else the slightest clue what you didn’t like that I said. Obviously, something I said set you off … but what?

    So yes, I will fight for clarity, bushbunny. I will fight for references and citations, that’s what science is about, not vague handwaving statements like you use to attack me. You want to attack me, I’ll insist that you say exactly what you are attacking, not just make vague statements about what a jerk I am.

    In particular, I will insist that people quote my words. I can defend my own words. I cannot defend your fantasies about my words.

    As to my “manner and the way you are rude and dismissive” to those who disagree with me, I have no objection to people who don’t agree with me. Quite the opposite. I thrive on them. They are my hope and my salvation. They keep me from going of the edge by pointing out my mistakes. Science is built on disagreement.

    However, I don’t suffer fools gladly. Now, I’m working on that. I’m trying to be more Canadian, Steve McIntyre is my guru and guide.

    But I doubt that I’ll get to the point where I’ll accept a lecture on manners from some anonymous bushbunny who is unwilling to sign his real name to his own words. You can disavow your strongly held claims at any time. You can say anything you want and never have to stand behind it.

    You take responsibility for nothing, and you have the gall to want to lecture me on responsible behavior? Ain’t gonna happen.

    So I’m sorry, bunny … but I don’t take instruction on proper action from a man who doesn’t have what it takes to stand behind his own actions.

    w.

  231. Phil. says:

    Dr. Strangelove says:
    April 14, 2014 at 8:35 pm
    George smith

    “The “band” spectra of molecules and the line spectra of atoms, do not follow the same rules as the continuum spectra of thermal radiation such as black body spectra.”

    Atoms and molecules are considered as gray body. They follow the blackbody spectra but reduced by their emissivity less than 1. The shape of the curve is the same but the area is smaller.

    No they aren’t, emissivity is a function of wavenumber so the shape of the curve is not the same!

    Here’s the black body for 300K:
    http://i302.photobucket.com/albums/nn107/Sprintstar400/BB.png

    Here’s the CO2, H2O and CH4 spectra (note the different wavelength ranges):
    http://www.nist.gov/pml/div682/images/DIALFig2-Copy.jpg

  232. Trevor says:

    Willis:

    I’m not “attacking” anyone, and I’d appreciate you not getting me confused with other people on your hit list. I am, generally, on the same side of the CAGW debate as Dr. Sheahen and yourself. I merely pointed out a possible oversight in his analysis, without any accusation of disingenuousness.

    However, for the record:

    “The amount of CH4 must increase 100-fold to make it comparable to H2O.”

    I took this statement to mean something very different from your interpretation. Based on the context, it seems to me that he is saying that Methane levels must increase by a factor of 100 for its effect to be equal to that of Water Vapor. Of course, given that Water Vapor fully absorbs all the IR in that 3.3-micron range, increasing methane a MILLION times current levels STILL wouldn’t result in any more absorption of IR than is already being absorbed, because there’s just not any more IR left in that range by the time the water vapor gets done with it. But it’s not like the water vapor gets first crack at it and then methane gets the “leftovers”; they are both absorbing IR in that band simultaneously, so my little crack is just that, a crack, not representative of reality. But whichever GHG absorbs a particular IR particle matters not in the grand scheme of things, because all of them in that range are going to be absorbed by one or the other, so increasing the concentration of either will not result in more warming, at least not in that range of the IR spectrum. That’s how I took the quote above, and I believe, if you ask Dr. Sheahen, you’ll find that’s what he meant.

    As for whether Dr. Sheahen said that water vapor absorbs ALL the IR that methane might absorb, I offer the following quotes, with explanation of how I interpreted them:

    The Title: “Methane: The Irrelevant Greenhouse Gas:”
    Without a modifier like “mostly”, the word “irrelevant” all by itself implies TOTAL irrelevance. For example, if I had read over your post and found a grammatical error, I could not say that the text of your post was “grammatically correct”. I would instead say that it was “MOSTLY grammatically correct”. (By the way, I did not find a grammatical error.)

    In the third-to-last paragraph: “Hence, ANY radiation that CH4 might absorb has already been absorbed by H2O.” (emphasis mine)
    Okay, he didn’t use the word “all”. But however you parse this sentence, it means the same thing.

    The next sentence, just before the sentence you quoted: “The ratio of the percentages of water to methane is such that the effects of CH4 are COMPLETELY MASKED by H2O” (emphasis in the original – I don’t know how to bold text here, so I capitalized it instead).
    He not only used the word “completely”, but EMPHASIZED it.

    (Note that, even if you ignore the IR in the 3.6-3.8-micron range that I have made an issue of, I still don’t think this sentence is accurate, in the respect that it is not the relative percentages of water to methane that makes methane’s contribution to absorption irrelevant, but the fact that the ABSOLUTE percentage of water alone is sufficient to fully absorb all the IR in the 3.0-3.6-micron range regardless of the percentage of methane.)

    In the second-to-last paragraph: “The high per-molecule absorption cross section of CH4 makes NO DIFFERENCE AT ALL in our real atmosphere.” (emphasis mine)
    None at all means exactly the same thing as zero, to the last decimal place. It doesn’t mean 1%. It doesn’t mean 0.1%. It doesn’t mean 0.00000000000000000000001%. It means ZERO.

    You have put me in the uncomfortable position of vehemently disagreeing, over a bit of minutia, with people that I generally agree with on the overall topic of anthropogenice global warming. I’m sure Dr. Sheahen’s overall point is “mostly” correct, and would be happy to agree with him, if he had only been less absolute in his statements. I have shown four occasions where he unequivocally stated, in different ways, that Methane’s contribution to greenhouse warming is zero. Not “nearly zero”. Not “negligible”. Not “mostly irrelevant”. Zero, period. And the one instance where you claim he specifically states that methane has an effect, I interpret that sentence very differently, and in any event, the specificity of that statement with regard to what you claim it means is nowhere near as specific as the four times he stated a zero contribution.

    If our esteemed president had said “If you like your health care plan, you can PROBABLY keep it”, then that would not have been false, as I’m pretty sure more than 50% of Americans did not lose their insurance when Obamacare went into effect. But that’s not what he said. He said “if you like you health care plan, you can keep it. Period. No matter what.” Now, if you want to argue that Dr. Sheahen didn’t add “Period. No matter what” to his conclusion that water vapor absorbs all the IR that methane would have absorbed, and that means he didn’t really mean it to be an absolute statement (as Obama apparently didn’t mean his statement to be absolute, even WITH the “Period. No matter what”), then feel free to do so. OR, simply agree with me that methane’s effect is greater than zero (as you already have) AND that Dr. Sheahen has understated this effect as an unequivocal zero (which you have not, despite the evidence).

    It was not my intention to pick a fight with you, Willis, or Dr. Sheahen. I simply wanted someone who knew more about it than me to weigh in on what I perceived to be a gap in H2O saturation of the methane absorbtion band that was not addressed, or even acknowledged, in Dr. Sheahen’s essay. But unless I misread the graph, the gap exists, and i was hoping someone could reinforce, with hard data and rigorous analysis, my suspicion that methane’s absorption of IR, in that .2-micron gap, is so small as to be neglible (but not so small as to be zero). Because this is the kind of argument that I would like to present to my alarmist friends and colleagues, but I cannot do so in good conscience if I cannot convince myself that it is accurate.

    Regards,
    Trevor

  233. Willis Eschenbach says:

    Trevor says:
    April 15, 2014 at 1:10 pm

    Willis:

    I’m not “attacking” anyone, and I’d appreciate you not getting me confused with other people on your hit list. I am, generally, on the same side of the CAGW debate as Dr. Sheahen and yourself. I merely pointed out a possible oversight in his analysis, without any accusation of disingenuousness.

    Trevor, this is why I asked you before to quote what Dr. Tom said that you disagree with. You didn’t quote Tom’s words upstream. Instead, you took exception to something he never said.

    In response I commented:

    So … you’re attacking something he didn’t say. We all know, including Dr. Seagal, that methane has some effect. The question is the amount.

    Now, please note that I said you were attacking someTHING. In particular, you were attacking something Dr. Seagal hadn’t said …

    Now, you are attacking someTHING I didn’t say. I didn’t accuse you of attacking someONE, as you fatuously claim. I accused you of setting up a straw man and demolishing it, of attacking a claim that was never made. I never said you attacked anyone, neither me nor Dr. Seagal.

    So QUOTE THE WORDS YOU DISAGREE WITH!!! Twice now you’ve gone off on a tangent, objecting strongly to someTHING that someone never said. It’s a tiresome habit, and neither Dr. Seagal nor I can defend something we’ve never claimed.

    w.

  234. bushbunny says:

    Willis, how do we know you are whom you say. Keep out of the kitchen? I do not like the manner you approach others, not your science. Gravatars are there as not a protection but an identity.
    I use it all the time on blogs, and I am female not male. Can’t you tell? Won’t shut up.

  235. Willis Eschenbach says:

    bushbunny says:
    April 15, 2014 at 6:32 pm

    Willis, how do we know you are whom you say.

    Because I’ve met a number of people who post here—Anthony, various scientists and commenters, the moderators. You can ask them. I traveled around England and Scotland last year, so you could ask say Lord Christopher Monckton if I am who I am, or any of the other folks who I met there. Then of course I’ve spoken at various meetings, there’s video of me on line. My life is an open book, bushbunny. You picked the wrong man to ask that question of.

    Keep out of the kitchen? I do not like the manner you approach others, not your science.

    And why should I care what some anonymous person who won’t sign his/her own words thinks of my manner? I told you, I don’t take instruction on responsibility and manners from someone who will not take responsibility for their own words.

    Gravatars are there as not a protection but an identity.
    I use it all the time on blogs, and I am female not male. Can’t you tell? Won’t shut up.

    I don’t care what excuse you put up for your anonymity, or what reasons you have for not standing behind your words. If you don’t have the nerve to do that, I couldn’t care less why you don’t have the nerve. Maybe it’s genetic, maybe it’s work related, who cares? The fact is if you post under a false name, then what an anonymous bushbunny might like or dislike has little weight, and rightly so. Who cares what unidentifiable bushbunnys think?

    Now science, that’s another matter. Science stands or falls on whether the idea is right or wrong, not who proposed it or champions it.

    But opinions on my manner? Sorry, bunny. If you want to run with the big dogs, you’ve got to live like the big dogs. In other words, if you want to have your personal opinions have some weight, you’ve got to sign your own name to them.

    w.

  236. Trevor says:

    Willis:

    Come on, Willis. I’ve seen many of your posts here, and I know you can do better than arguing SEMANTICS. I did not attack anyone OR anyTHING (at least not in my initial post on this thread). There! Is that better? But I would point out to you that, for most people, attacking their work, their words, their opinions, or their beliefs, is exactly the same as attacking them personally, because many people consider such products of their minds to be part of who they are. They DO take it personally, and so, in this case, the distinction between attacking the person and attacking his work is immaterial. And the accusation of attacking his work is materially equivalent to the accusation of attacking him personally. Had I TRULY attacked his conclusions (as you accused), Dr. Sheahen would have been right to accuse me of attacking HIM personally, because any such attack would not have been directed at some inanimate object (as you imply with “someTHING”), but at the product of Dr. Sheahen’s mind. BUT, I did not “attack” Dr. Sheahen’s conclusions; I merely pointed out a potential flaw, which I admitted was probably minor. But now, if we’re done arguing semantics, can I get an apology from you for accusing me of “attacking” Dr. Sheahen’s work, since, even if you don’t equate that to an accusation of a personal attack as I do, you must admit the accusation is false nonetheless, because my words were not anywhere near strong enough to constitute an attack on anyone OR anyTHING.

    Contrary to your accusations of “attack”, I merely pointed out a possible flaw in Dr. Sheahen’s analysis. You denied (before I provided quotes) that Sheahen said what I understood him to say, in the process agreeing with me that IF he had said what I understood him to say he would have been wrong (no, you didn’t use those exact words, but that’s what is implied by “We all know, including Dr. Seagal [sic - but to be fair, I think I may have made that error first, and you merely copied it, assuming I had used the correct name, so I'll take the blame for that one], that methane has some effect.”). So I pointed out FOUR instances in which Dr. Sheahen’s OWN WORDS, though not an exact duplicate of mine, clearly indicated his conclusion that the effective warming of incremental atmospheric methane is exactly zero. And instead of adressing the SUBSTANCE of my argument, you are focusing on a misstatement I made about whether you were accusing me of attacking a person or a thing. And in the process, you have now attacked ME (not someTHING) TWICE (I guess you’ll need quotes on that, so I’ll append them below). And you continue to deny what Dr. Sheahen clearly said, without even addressing my evidence that he said it. Even after I QUOTED him for you like you demanded (and before you get semantic again, I think putting it in all caps amounts to more of a demand than a request.)

    So, in the interest of actually getting somewhere in this discussion, I ask you to ignore minor semantic disagrements for long enough to address the four QUOTES, from Dr. Sheahen himself, that I believe to clearly inidicate his conclusion that methane’s net marginal contribution to warming is exactly zero

    Also, please note, for the record, that the only reason I did not include quotes from Dr. Sheahen’s essay in my original post was that I believed, at the time, that it was CLEAR to anyone who had read the essay, what Dr. Sheahen was saying. In fact, it never even occurred to me that someone with a high-school level of reading comprehension could read that essay and come to the conclusion that Dr. Sheahen did not say that the net effect on surface temperature of additional methane in the atmosphere was zero. Though I still maintain that I am right about what Dr. Sheahen said, I concede that I was wrong about how “clear” it was, since at least one person here did not understand it. If you still think that I am also wrong about what he said, then, as I have already asked, put this argument over semantics behind you and address the four quotes that you asked for and that I supplied (and that you subsequently ignored, despite asking for them).

    Trevor

    *As promised, quotes from your two replies to me that were attacks on me:

    From your first reply to me:

    “So … you’re attacking something he didn’t say”
    You accused me of ATTACKING something. Not just some inanimate object, but a “thing” that was the product of a person’s mind, which that person considers a part of himself and a reflection upon himself. But even if you maintain that it was just a “thing” you accused me of attacking, you were still accusing me of aggressive behavior (and even you must admit that attacking somone’s behavior is completely indistinguishable from attacking that person).

    From your second reply to me:

    “Instead, you took exception to something he never said.”
    Here you are accusing me of putting words in Dr. Sheahen’s mouth, then taking exception to them. In effect, you are accusing me of dishonesty. Now, I admit that, at the time you first took exception to my exception-taking, I had not provided quotes. However, at the time you posted this attack on me, I had provided those quotes, which I believe clearly support my claim about what he said. Yet, without even revisiting your conclusion that he never said it, in light of the newly-quoted evidence, you continued to accuse me of misquoting Dr. Sheahen.

    “I didn’t accuse you of attacking someONE, as you fatuously claim.”
    If you know the meaning of the word “fatuous”, then no further explanation is necessary. Except to repeat that, when the “thing” that is the target of an attack is so intimately entwined with the person’s identity, the attack IS, for all intents and purposes, on the PERSON himself.

    “So QUOTE THE WORDS YOU DISAGREE WITH!!! ”
    The use of all-caps is clearly meant as a criticism of my inability to follow your instructions in your first reply to me. Not only is it insulting, it is also WRONG. I did, in fact, use quotes from the original essay, exactly as you requested. I did not quote your words (the “attack” accusation) from the first reply because at that point the conversation was exclusively between you and me, and you presumably know what you said to me, and would have no problem finding it with the key word “attack”. The only purpose for quotes is to make sure everyone involved in the discussion knows what the person you are replying to actually said. Again, you and I are the only people involved in the discussion of this specific topic, so I took it for granted that you already knew what you said, and if I got it wrong (as I arguably did, if you argue fatuously), you could easily defend yourself without having to search the entire page for what you said. So your demand for quotes, in this instance, is just silly, and I believe, nothing more than a distraction contrived to avoid addressing my evidence of what Dr. Sheahen concluded.

  237. bushbunny says:

    Willis, obviously you are a public figure and overtly involved in climate science to dispute the IPCC and others who are writing rubbish. It is best you use your name to publicize yourself. (And self promote your status in the scheme of things) I don’t in anyway criticize or condemn you for that of course. However, Anthony knows who I am, I’m sure he will let you know if it concerns you so much. It is your manner for putting down people and suggestions such as ‘get out of the kitchen,’ as I find most bloggers here are very polite and I would expect someone as famous as you to be the same. Run with dogs, oh, come on Will you are sidelining others who don’t sign the real names, as pitiful in your estimation. We are on the same side I think? And an opinion is just as relevant as a scientific graph, that most people take for granted as correct anyway. Well I don’t the conclusions gained are my main concern. PS. I love dogs, some have been my best friends in life. But if they bite me, they find a new home. Goes for any pet or man I have married.

  238. Willis Eschenbach says:

    bushbunny says:
    April 16, 2014 at 8:14 pm

    Willis, obviously you are a public figure and overtly involved in climate science to dispute the IPCC and others who are writing rubbish. It is best you use your name to publicize yourself. (And self promote your status in the scheme of things) I don’t in anyway criticize or condemn you for that of course.

    You asked me how you could know who I am. I told you. I am amused by you telling me that you do not condemn or criticize me for standing behind my own words and using my real name … that’s awfully generous of you.

    However, Anthony knows who I am, I’m sure he will let you know if it concerns you so much.

    It doesn’t concern me or interest me in the slightest. You choose to be anonymous. I respect that. I almost never attempt to pierce someones anonymity, I view that as highly improper.

    It is your manner for putting down people and suggestions such as ‘get out of the kitchen,’ as I find most bloggers here are very polite and I would expect someone as famous as you to be the same.

    Run with dogs, oh, come on Will you are sidelining others who don’t sign the real names, as pitiful in your estimation.

    I don’t think people who post anonymously are pitiful. I simply have observed that nobody pays much attention to opinions from random anonymous bunnies on the internet. And why should we? For all I know you are twelve years old … why should your anonymous opinion be of interest to anyone?

    Next, it appears you didn’t understand what I meant by “If you run with the big dogs, you have to live like the big dogs”. It means that if you want to play big league baseball, you have to do what big league baseball players do.

    In terms of your opinions carrying weight, what that means is that you have to do what those of us whose opinions carry weight do … and the very first thing in that list is SIGN, DEFEND, AND LIVE WITH WHAT YOU HAVE SAID.

    You see, bunny, because you are anonymous you don’t have to stand behind your words. You can disappear and come back tomorrow as “paulbunnyan” and I’ll never be the wiser.

    Me, I don’t have that option. If I make a claim, I have to back it up or take it down. I cannot walk away from it as you can.

    This should not be news to you, that anonymous opinions sell at a deep discount. It’s the same reason that police can’t use anonymous informants to get a search warrant—the informant can walk away from their words. It’s the ugly reality of the world—you can be a bushbunny if you want, but nobody will pay any attention to your opinions. If you want to run with the big dogs, you have to live like the big dogs.

    We are on the same side I think?

    Can’t say. I haven’t a clue whether you understand what “side” I’m on, as I consider myself a climate heretic rather than a skeptic. And I’m quite certain I don’t understand what “side” you are on … so I fear I can’t answer your question.

    And an opinion is just as relevant as a scientific graph, that most people take for granted as correct anyway.

    Not in a scientific discussion.. A scientific graph, a proper one, is a graphical representation of facts with an estimate of their error. In a scientific discussion, those facts carry weight. On the other hand, your opinion or mine carries no weight in a scientific discussion. Any of my opinions, for example whether I really, truly believe something is true, is IMMATERIAL in such a discussion. How much I believe something is just opinion, and carries no weight at all in a scientific discussion.

    And rightly so. Science is a method, not a thing. It’s a method for determining what we might call “provisional scientific truth”. Here’s how it works. I put my scientific claim out there, with all the code, data, logic, explanations, math, observations and any other support I can find.

    Then I hand around the hammers and invite everyone to find something wrong with my claim. So they marshall their code and data and logic etc etc and try to smash my beloved idea to bits.

    If they can smash it, if my claim is “falsified”, it joins the long list of all of the other falsified scientific claims throughout history. And if they can’t find fault with it, my claim is accepted as provisional scientific fact … until someone comes along who can find something wrong with it.

    Note that in that entire process, it doesn’t matter in the slightest what your OPINION of my claim might be. And that’s true whether you are anonymous or not. Either you can show that I’m wrong, or you can’t. Nothing else matters.

    So I’m sorry, but neither your opinion nor mine are “just as relevant as a scientific graph”. In a scientific discussion of the graph, opinions are not relevant at all.

    Well I don’t the conclusions gained are my main concern. PS. I love dogs, some have been my best friends in life. But if they bite me, they find a new home. Goes for any pet or man I have married.

    I suppose in your real life, those kinds of threats might keep both your husbands and your dogs in line. And they are certainly reasonable rules for life regarding husbands and pets.

    But it seems you still don’t grasp your position here. You are a random, anonymous internet popup, but you think your opinions are important. Hey, grab a number and stand in line, we have hundreds of folks just like you. So in this case, you threatening to take your ball and go home if you think someone is biting is meaningless here. Do what you wish.

    On the other hand, if you want to stick around, there’s lots to be learned on this site. Heck, you can avoid me entirely and find heaps of interesting stuff.

    So let me invite you to stay. And let me invite you to use your real name. My comment about the big dogs was not meant to shut you out. It was an invitation to come run with us, and a comment on what you need to do if you want to take that run …

    Or not. It’s up to you, and I support you making either choice. I’m just trying to point out the consequences of that choice. In the big world, folks don’t pay much attention to anonymous voices. That’s not a value judgement on you or anyone being anonymous. It’s just the price you pay for anonymity in every society I’ve been in, so you should not be surprised that it’s that way here as well.

    All the best,

    w.

  239. bushbunny says:

    Actually Willis, adding my real name wouldn’t change your opinion it seems anyway just from your attitude to me. However, I am very proactive in political circles, and writing letters to newspapers, (when I use my real name) when it comes to anything to do with bogus AGW predictions and clean energy. Especially the methane sent out by poor hapless ruminants. I do have a degree in archaeology and palaeoanthropology, a GCA, in archaeology and ancient history, and a Diploma in Organic agricultural production. (It was hard as I am not a farmer but was allowed to sit it because of former certificates in horticulture and organic farming and horticultural principles). This is in Australia of course.

    But in POLITICs, I was involved in a five year long debate with our former Federal MP Tony Windsor on this, I had supported him on all of his election campaigns and was once on his think tank so to speak, and we eventually parted and I told him why? He retired instead of standing because of ill health he stated. There was support for his mate who owns a solar panel company who stood in for him and although I was present in supervising the count at the largest polling station, Rod Taber didn’t get so many primary votes, but most of the labor and green factions awarded him their preferences. (These are counted of course in the final result). So whatever I blog here, has some basis and foundation because I am interested in putting Mann et al, back into their place in history as frauds. It is not ‘just’ an opinion from an anonymous person.

    This blog is not just about science (although contradictions of known data compiled by IPCC and Mann etc., are a big factor) it is also about politics and manipulation of ideologies and confounding the masses to believe we can alter the weather etc., and turn to alternative clean energy sources to save the planet. This is what interests me more, than more graphs to prove your own personal worth in scientific analysis. I suspect you have also provided these for publication in some scholarly magazine or paper? That’s where it will have peers who can overview your data, not only me and others. I am not trying to put you down with this last comment, I am just suggesting and asking if you had? It’s fine to preach to the converted I suspect.

    I almost unsubscribed from this site (but the British bull dog in me, let me hold on), just because of your personal comments about me. Not your science graphs etc., and I congratulate Anthony on his blog, although some of the different themes do not interest me as much as others, then I don’t comment. But your nasty comment on my ‘opinion’ regarding the Thera eruption, you had never heard of? I didn’t put down references, because it was a subject in a post graduate essay.
    But I can’t believe anyone hadn’t heard of Thera (or Santorino) it’s still active too. Anyone can Google it and there are many on line scholarly papers on this subject on the web.

    I am also a published author too.

  240. Willis Eschenbach says:

    bushbunny says:
    April 17, 2014 at 8:58 pm

    I almost unsubscribed from this site (but the British bull dog in me, let me hold on), just because of your personal comments about me. Not your science graphs etc., and I congratulate Anthony on his blog, although some of the different themes do not interest me as much as others, then I don’t comment. But your nasty comment on my ‘opinion’ regarding the Thera eruption, you had never heard of? I didn’t put down references, because it was a subject in a post graduate essay.

    Congrats to the bulldog. That strain in the British nature is a marvelous thing. But what on earth are you talking about? Thera eruption? Post graduate essay? Never heard of?

    I’ve never heard of any of this. Are you sure you are on the right thread?

    Making this kind of accusations without QUOTING MY WORDS just loses you credibility with me, bushbunny. I have no clue what it was I said about the Thera eruption that has your knickers in such a twist. I assume it must have been a bad thing in your opinion, given your comments. And perhaps it was.

    But how would I know if it was good or bad, when I have no idea what you are talking about? Perhaps it’s obvious to you, but I read hundreds of comments a day … just what the heck are you on about?

    Apparently you didn’t notice, or didn’t believe me upstream when I said to you (emphasis mine):

    I’m not asking anything of anyone that I’m not asking of myself. I quote what others say so you and others can understand my objections, and I insist that others do the same.

    So the sight of you clutching your pearls and earnestly declaiming what a bad man I am for making some unknown comment about Thera mumble mumble?

    Sorry, that just makes you look like a drama queen. Without specifying what bad thing you think I’ve done, that’s nothing but slinging mud, bushbunny.

    I am happy to defend whatever I said, or to apologize to you for it if I did or said wrong things.

    What I can’t defend is your vague reference to some unknown thing you think I said somewhere about something. I’m not going searching for the word “Thera” and then try to guess which of my comments about Thera you didn’t like.

    I wasn’t kidding above. If you want to hold a dialogue with me, and I’m always interested in that, then I insist that you quote my exact words that you are objecting to. I’m not willing to discuss science with people who throw mud at the wall in the hope that it will stick. And so far, that’s what you’ve done.

    For example, you imply that I’d never heard of Thera … say what? How can I defend myself against such a vague, underhanded charge like that, when I haven’t a clue where you got such a misconception. Where did I say that, and exactly what did I say?

    Sorry for the straight talk, bushbunny, but I don’t take that kind of underhanded vague, content-free accusation of bad behavior from man, woman, or chimpanzee for that matter. I’m happy to have anyone disagree with me. But I insist that you quote EXACTLY what you disagree with, so we can all understand what has you breathing so hard.

    w.

    PS—I was serious about approving of your bulldog nature. It is an endearing quality in anyone, especially women. My dear lady wife is a serious bulldog … she’d have to be, I suppose, living with me.

  241. bushbunny says:

    Well I can’t remember exactly which thread it was, possibly regarding the effect of volcanoes on the climate. I mentioned Thera and also some ancient Chinese chronicle that recorded seven years of famine etc. My credibility is not lost to me, Willis. I delete posts as soon as I comment, but if you keep them, then look at a thread from which volcanoes featured.

    Oh, I asked if you had been published in any scholarly papers or magazines. Just asking? To me you are using this site and blog to self serve your own credibility and reputation. That is my OPINION.

    Willis, I have been confronted many times in my life just being a feminist, and a liberal one too, not a man eater or hater. And the way you are pursuing this is definitely defensive and unnecessary. Send my kind regards to your wife. And with that I refuse to enter into any more on this it is getting rather boring to me, and THAT IS MY OPINION.

  242. bushbunny says:

    ps. Willis how old are you? I’m 71 and still studying.

  243. Willis Eschenbach says:

    bushbunny says:
    April 18, 2014 at 1:13 am

    Well I can’t remember exactly which thread it was, possibly regarding the effect of volcanoes on the climate. I mentioned Thera and also some ancient Chinese chronicle that recorded seven years of famine etc. My credibility is not lost to me, Willis. I delete posts as soon as I comment, but if you keep them, then look at a thread from which volcanoes featured.

    Great. You’re so mad at me about something I supposedly said that you’re gonna take your ball and go home, and you don’t even know what it is I said? Yeah, that makes you look like a really rational bunny… plus now you’re mad at me for pointing it out?

    Gotta say, you’re not giving bunnies a good name here, you’re fulfilling all the bunny stereotypes.

    Oh, I asked if you had been published in any scholarly papers or magazines. Just asking? To me you are using this site and blog to self serve your own credibility and reputation. That is my OPINION.

    Yes, I’ve published a few pieces in the scientific journals, including a peer-reviewed “Communications Arising” in Nature magazine, and three other peer-reviewed pieces.

    As to whether I am “using this site to self serve”, I am far and away the most popular guest author here. I get about a million page views per year. I am overjoyed to be published here, it’s a superb site. I bring lots of folks to the site, I write interesting pieces that are often controversial and that engender interesting comments and discussion. Anthony is happy to have me publishing here.

    I don’t see anyone is using anyone in this story.

    Willis, I have been confronted many times in my life just being a feminist, and a liberal one too, not a man eater or hater. And the way you are pursuing this is definitely defensive and unnecessary. Send my kind regards to your wife. And with that I refuse to enter into any more on this it is getting rather boring to me, and THAT IS MY OPINION.

    Running away so soon? So your story about being a bulldog was just words? You talk about being a bulldog, but you don’t want to do what it takes to run with the big dogs?

    Ah, well. Your choice. Please be clear, however, that I have not accused you of being a feminist, a liberal, a “man eater”, a “man hater”, or anything of the sort. I neither said nor implied that, nor anything even remotely resembling that.

    However, instead of actually quoting me as I’ve requested, I see you sneakily tossing those words out there, hoping they’ll stick to me and folks not paying attention might believe I accused you of such things … not gonna happen, bunny. That’s all on your side of the screen. I said no such thing. I can see why you are so unwilling to quote me … because your fantasies are so very far from anything I actually said.

    Finally, you say that I am being “defensive” … look, bunny. You popped in here to tell me that I’m a bad guy, so bad you are going to never read the site again … but you can’t find whatever it is that you’re so angry at me about. You accuse me of things I’ve never done, question my credibility, and refuse to quote whatever it is that has you wound up so tight … damn right I’m defensive, and I’ll tell you why.

    Because you are being so offensive.

    You set out to bite me, bushbunny, and now you’re all shocked and surprised that I bite back? Did you expect me to be nice to you because you’re a bunny? I thought you were the one arguing for bunny equality … well, this is part of equality—you get held to the same standards as everyone else, no special treatment because you’re a bunny.

    In any case, I wish you well whether you stay or go.

    w.

  244. Willis Eschenbach says:

    bushbunny says:
    April 18, 2014 at 1:18 am

    ps. Willis how old are you? I’m 71 and still studying.

    Me? I was born yesterday …

    w.

  245. Willis Eschenbach says:

    Willis Eschenbach says:
    April 18, 2014 at 2:49 am

    bushbunny says:
    April 18, 2014 at 1:18 am

    ps. Willis how old are you? I’m 71 and still studying.

    Just kidding. I’m sixty-seven, last I looked, and still studying. And still doing research. And still writing it up. And still working a day job pounding nails, I’m a house builder.

    What’s your objective in asking? Are you looking for bonus points on account of your age? Sorry … I’m an old goat myself, old bunnies can’t gain any advantage there.

    w.

  246. bushbunny says:

    Willis, no comment!

  247. bushbunny says:

    Willis as this theme is about methane, [easy ... Mod]

  248. bushbunny says:

    Thank you Moderator, but I stand by my comment but remember I tend to be sardonic not spiteful.

  249. Lewis P Buckingham says:

    juhttp://www.historymuseum.ca/cmc/exhibitions/civil/greece/gr1040e.shtml
    Just a bit about the Thera Eruption.
    Lot of CO2 here, not sure about the methane.

  250. Trevor says:

    Willis:

    I’m still waiting for a reply from you about the quotes you demanded (proving that Sheahen concluded that the warming effect of additional methane is zero), and which I supplied. Your first reply did not address those quotes, but instead belittled me (as a blatant attempt at distraction) for misreading your reply to my first post (and No, Willis, I’m not going to repsond to any more of your childish demands for quotes on this topic; you know what you said and you know how you meant it; besides, you’ve proven that, even when I do provide quotes, you just IGNORE them). And so I posted another reply, explaining the lack of difference between attacking a person and attacking a “thing”, when that thing is a product of a person’s mind. In any event, if it will get you to address those four quotes from my first reply to you, and explain how they do NOT prove that Sheahen’s conclusion was as I stated it, then I will gladly concede any argument between you and me over semantics.

    Regards,
    Trevor

  251. bushbunny says:

    Willis was engrossed after he wrote ‘My Friend Billy’ that erupted into a wild talk regarding religious beliefs. Some 509 posts! Most written by him. Maybe an exaggeration but it was quite amusing.

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