Wednesday, August 18, 2010

Why Greenhouse Gases Won't Heat the Oceans

        Climate scientist Roger Pielke, Sr has noted that land surface temperature records (which comprise the vast majority of temperature records prior to the satellite era (1979-)) are unreliable due to land use changes and urban heat island effects, and that we should therefore look to ocean heat content changes as the most reliable metric for assessing global heating and cooling. The oceans cover 71% of the global surface area and hold at least 1000 times more heat than the atmosphere. Many have claimed that the 'missing heat' from 'anthropogenic global warming' has gone into the oceans, even though the heat seems to be 'missing' from the oceans as well. Recent data from the ARGO network of ~3200 floating robot sensors has shown that since full deployment of the system in ~2003, the ocean heat content has declined despite steadily rising 'greenhouse' CO2 levels:
From Loehle 2009: Cooling of the global ocean since 2003
How could this be? Here are the physical reasons why increasing concentrations of 'greenhouse gases' would not be expected to increase ocean heat content:

1. Infrared radiation from 'greenhouse gases' causes evaporative cooling of the oceans rather than heating
LWIR wavelength is ~8-14 microns
        CO2 and other 'greenhouse gases' re-emit radiation to the Earth and space in the long-wave infrared (LWIR) portion of the electromagnetic spectrum. While ultraviolet and visible radiation from the Sun does penetrate the surface of the oceans to cause heating, the energy output of the Sun is relatively stable and obviously not linked to man. However, since the LWIR re-radiation from increasing 'greenhouse gases' is only capable of penetrating a minuscule few microns (millionths of a meter) past the surface and no further, it could therefore only cause evaporation (and thus cooling) of the surface 'skin' of the oceans. Stephen Wilde, LLB (Hons.), Fellow of the Royal Meteorological Society explains this in detail, excerpted below:
"However the effect of downwelling infrared is always to use up all the infrared in increasing the temperature of the ocean surface molecules whilst leaving nothing in reserve to provide the extra energy required (the latent heat of evaporation) when the change of state occurs from water to vapour. That extra energy requirement is taken from the medium (water or air) in which it is most readily available. If the water is warmer then most will come from the water. If the air is warmer then most will come from the air. However over the Earth as a whole the water is nearly always warmer than the air (due to solar input) so inevitably the average global energy flow is from oceans to air via that latent heat of evaporation in the air and the energy needed is taken from the water. This leads to a thin (1mm deep) layer of cooler water over the oceans worldwide and below the evaporative region that is some 0.3C cooler than the ocean bulk below."
The recent paper by Roy Clark, PhD also discusses the physics and concludes, "Application of Beer’s law to the propagation of solar and LWIR [long-wave infrared] flux through the ocean clearly shows that only the solar radiation can penetrate below the ocean surface and heat subsurface ocean layers. It is impossible for a 1.7 W.m−2 increase [predicted by the IPCC due to man-made greenhouse gases] in downward ‘clear sky’ atmospheric LWIR flux to heat the oceans." (p. 196). Increasing levels of IR-active 'greenhouse gases' would instead be expected to cause increased evaporative surface cooling of the oceans. N.B. there is also a negative feedback phenomenon on CO2 levels discussed in a paper published in Nature which shows that the evaporative cooling of the ocean 'skin' from increased downwelling IR allows increased uptake of CO2 due to increased solubility of CO2 at lower temperatures.

2. Even if 'greenhouse gases' were capable of heating the oceans, the ocean heat capacity is so immense that there would be no significant change in ocean temperature
        The huge mass and heat capacity of the oceans regulates and stabilizes global temperatures to a far greater degree than any possible influence from mankind.
        The immense heat capacity of the oceans can be illustrated by assuming the oceans could be heated one-way by all solar energy absorbed by the Earth, and assuming no cooling due to convection, evaporation, or radiation. The oceans hold 1.3 billion cubic km of water. Assuming the density is 1 kg per liter, the mass of the oceans is 1.3 billion billion kg or 1.3 yotta grams. The total solar power absorbed by the Earth in one year is 89 peta Watts (PW):
        For a thought experiment, assume all 89 PW are taken up by the oceans and that the oceans don't release any of that heat. That would add 0.67 yotta calories to the 1.3 yotta grams, resulting in an increase in the ocean temperature of only 0.5C after an entire year.
        Now, let's also assume that the IPCC is correct that 'greenhouse gases' are causing 1.7 W/m2 'radiative forcing,' and that it is possible for this IR 'back-radiation' to penetrate and heat the ocean (even though we've already shown that is impossible above). The 1.7 W/m2 works out to 850 Tera watts (TW) [or .85 PW] when multiplied by the total Earth surface area of 500 tera square meters. Thus, the IPCC claims that 'greenhouse gases' are preventing .85 PW of energy from leaving the atmosphere to space. This .85 PW is less than the 89 PW from the Sun by a factor of 105 times. Plugging this into our thought experiment above shows that the change in ocean temperature from 'greenhouse forcing' would be 0.5C/105 or .005C in one year or only 0.5C after 105 years, assuming the oceans release none of this added heat!  In reality, of course, the oceans would release all or most of this added heat by convection, evaporation, or radiation, leaving at most only a few hundredths of a degree temperature change after 105 years. Thus, it is impossible for 'greenhouse forcing' to raise ocean heat content to any measurable degree, or cause melting of the icecaps from below, or increase sea levels from thermal expansion.

3. The Second Law of Thermodynamics requires heat to flow one-way from hot to cold.
        Since the atmosphere is colder (average radiating temperature of ~ -10 C) than the ocean surface (~ 17 C), the 2nd Law of Thermodynamics states that heat can only be transferred one-way from the ocean surface to the atmosphere, not the other way around.

1. The latest Chilingar et al paper also discusses heat capacity of the atmosphere, which should decrease due to added CO2: "saturation of the atmosphere with carbon dioxide, with all other conditions being equal, results not in an increase but in a decrease of the greenhouse effect and average temperature within the entire layer of planet’s troposphere. This happens despite intense absorption of the heat of radiation by CO2. The physical explanation of this phenomenon is clear: molecular weight of carbon dioxide is 1.5 times higher and its heat-absorbing capacity is 1.2 times lower than those of the Earth’s air. As a result, the adiabatic exponent for a carbon dioxide atmosphere, at the same all other conditions, is about 1.34 times lower than that for a nitrogen–oxygen humid air"
2. Another empirical analysis which finds increased CO2 leads to increased cooling  
3. Sea surface temperatures have been on a long-term decline since the Medieval Warming Period (~1000 years ago),  Roman Warming Period (~2100 years ago), and Egyptian Warming Period (~3100 years ago):
4. NOAA says the oceans are the drivers of global temperature, not the land surface.
5. Dr. Pielke asks whether James Hansen's GISS model should be rejected as unskillful.  


  1. Great post! The extreme emphasis by so many scientists on radiation and the greenhouse effect is silly.

  2. I am horrified at the idea that anyone would consider this an accurate assessment of the Earth's current state.

    Do you realise how ridiculous it is to take a 12 year sample of weather patterns that have been in existence for more than 2 billion years. Should you have been educated in the field and knew your statistics you too would realise this. To put it in perspective (since the numbers are roughly similar) what you are suggesting is as ridiculous as it would be to make a full analysis of the human population having just met two randomly selected people.
    Your data is statistically insignificant and you cannot, therefore, draw the conclusions you have from the data.

    Not to mention points 2 & 3 which take no account what so every for any of the other hundreds of processes that are involved. For example, in point 2 you say that "the Infrared radiation from 'greenhouse gases' causes evaporative cooling of the oceans rather than heating", but the fact that you have not even considered where this energy (heat) has gone i find alarming.

    The worst thing is that there are people who will read this as fact, and to those of you i urge you to read just some of the evidence that phenomenal amounts of research has produced and form your own opinion; i am convinced you will be able to discard this article as a piece of ill educated & highly bias drivel.

  3. George,
    Your comment makes no sense. What data specifically do you claim to be insignificant? If you don't think it is worthwhile to look at the satellite data and ARGO data, both of which show cooling instead of the AGW-model-predicted heating since 1998 then I guess you should stick your head in the sand until you think enough time has elapsed to illustrate the serious shortcomings of the AGW models and predictions.

    You just don't understand the science in point #2 & #3, so best you re-read it and read the paper by Roy Clark and post by Wilde which prove the same. When LWIR hits the surface of the oceans the heat goes into changing the state of water from liquid to vapor and there is no additional heat left over to heat the oceans. Read Wilde's thorough explanation.

  4. has anyone ever seen an experiment that compared the warming capacity of LWIR verses SWUV?
    I know an experiment cannot exactly reflect real world conditions, but it appears logical that it can put the physics on paper to a real world experiment and somewhat isolate the various spectrum and their different warming affect on H2o.

    I am also very intrested in the residence time of various TSI in all spectrum once it reaches the ocean, as this must be critical in determing net warming of the ocean over time verses short term atmosphere changes. Atmosphere warming can still mean global cooling is taking place.

    Any help is appreciated.

  5. Hi,
    Completely agree with everything (great article) except for the 2nd law of Thrmodynamics bit: "heat can only be transferred one-way from the ocean surface to the atmosphere". This applies to a solid object, heat can only flow from hot to cold. However when you have two objects emitting radiation (in this case Air and Earth) then both can receive and transmit energy. However the hotter body transmits more than the cooler body, so there is a net cooling of the hotter body and a net warming of the cooler body.
    So let's rewrite the statement to: "NET heat or energy can only flow from the ocean surface to the atmosphere".
    The tropics drives global energy levels, so my personal opinion is that the humid tropical air is already absorbing and transmitting all IRR in the finger frequency that CO2 can, so a tripling of CO2 shouldn't make much if any difference.

  6. If you are concerned about transfer of heat from atmosphere to ocean,get yourself an electrical heat gun and hold it over a bucket of water for 5 minutes. No heat transfer. reason, surface tension. NO heat transfer period.

  7. Anonymous is right, you cannot heat water from above on this planet due to surface tension. Science has made a huge mistake in assuming that the ocean surface will obey the second law of thermodynamics. science assumes that the second law of thermodynamics is universal but it hasn't checked, surface tension changes everything. The ocean only accepts radiation not physical heat. That is probably why we still have oceans.

  8. Link to RealClimate claiming that GHGs heat the ocean by decreasing temperature gradients between ocean and atmosphere:

    The only paper they could find shows the relationship between sea surface temp and LW forcing is 0.002ºK (W/m2)-1. In other words, a doubling of CO2 concentrations [alleged to cause 3.7 Wm-2 forcing] would increase sea surface temperatures by .0074 degrees - essentially zero.

  9. You must be kidding. is assumed by those who do not know any better to be an "objective" source on climate change. It features activist scientists with degrees in Geology, Geosciences, Mathematics, Oceanography and Physics who are all self proclaimed "climatologists". Yet skeptical scientists with equivalent credentials are not (probably because they have not proclaimed it). Essentially the site exists to promote global warming alarm-ism and attack anyone who does not agree with their declaration of doomsday (proven of course by their own computer climate models) and the need for government intervention against the life supporting, atmospheric trace gas, carbon dioxide.

  10. “It is well known that temperatures at the sea surface are typically a few-tenths degrees Celsius cooler than the temperatures some tens of centimeters below [Saunders, 1967; Paulson and Simpson, 1981; Wu, 1985; Fairall et al., 1996; Wick et al., 1996; Donlon et al., 2002].”

  11. Hi
    I have a question.

    It is well known that in the perpendicular plane, water is a very good absorber of LWIR and does not reflect LWIR. As no doubt most people know 50% of all LWIR is absorbed by water within just a few microns.

    However, is this angular dependant?

    Does anyone know whether at low incidence, say 10 degrees or less to the horizontal plane, whether water reflects some proportion of LWIR interfacing with water at that low incidence angle?

    I would be interested to receive feedback and particularly to any research on the subject.


    1. I'm pretty sure that the blog
      did an analysis of that a year or two ago

      you may want to search or ask there



  14. 3. The Second Law of Thermodynamics requires heat to flow one-way from hot to cold.
    Since the atmosphere is colder (average radiating temperature of ~ -10 C) than the ocean surface (~ 17 C), the 2nd Law of Thermodynamics states that heat can only be transferred one-way from the ocean surface to the atmosphere, not the other way around.

    OH NO! not that again.

    This is a very informative article but there you blow it completely.

    As you state, 2nd law tells us about HEAT transfer , hence "thermo"+ dynamic .

    IR is radiation, NOT heat. There is no law that says EM radiation cannot go from a cold to a hot body. Neither is there a law which says no form of energy can go from cold to hot.

    If that was the case we would not be able to observe the background radiation from space with a temperature of only 3 kelvin !!

    1. I'm very well aware IR is radiation and not HEAT and does travel from cold to hot bodies. However, it is not thermalized in the hot body i.e. it does not convert to HEAT.

      Lower-frequency lower-energy radiation from a cold body cannot make a hot body hotter. The reason is that all of those lower-frequency lower-energy quantum states are already filled in the hot body. This is referred to as frequency cutoff for thermalization. That is why there is a two-way transfer of radiation, but only a one-way transfer of HEAT. This is the basis of the 2nd law as stated above.