Written by Carl Brehmer
Brehmer Refutes Spencer
On August 23rd, 2016 Roy Spencer wrote an article in which he states that observational evidence gathered at Desert Rock, Nevada, affirms the existence of a radiative “greenhouse effect”. In that article he makes several assertions that I would like to address.
Let’s start with his definition of the “greenhouse effect” from the article, “the ‘greenhouse effect’ is usually expressed [as] the increase in surface temperatures caused by greenhouse gases compared to if those gases did not exist.” Just to be clear, the “increase in surface temperatures caused by greenhouse gases” according to the “greenhouse effect” hypothesis are overall average temperatures seen within a location, a region or the entire globe over time—the course of an entire day, an entire year, an entire decade or an entire Century. They are not just the nighttime temperatures that Spencer was studying and commenting on. As such his data is too limited to properly evaluate the existence or non-existence of a radiative “greenhouse effect” even as he has defined it.
Not only does he limit his data to nighttime temperatures, he also limited his data to clear sky conditions. Doing so eliminated critical data. When the humidity is high daytime surface insolation is lower than when humidity is low. Consequently, when the humidity is high daytime surface temperatures are lower. This decreases the average temperature present in a location, within a region or over the entire globe when the humidity is high—when the concentration “greenhouse gases” in the air is high. This is the inverse of the “greenhouse effect” as defined by Dr. Spencer, which again is an “increase in surface temperatures caused by greenhouse gases compared to if those gases did not exist.”
The cooling effect of water vapor, of course, is not limited to just the fact that its presence decreases the amount of sunlight that reaches the surface during daylight hours. When water is present within a climate system all of the following happen:
1) the surface is cooled by evaporation when water vapor is formed
2) water vapor increases the net, up-going, intra-atmospheric radiation heat loss rate, which moves thermal energy up the atmospheric column
3) latent heat transfer also moves thermal energy up the atmospheric column
4) when the humidity is very high the conditions for “moist convection” exist which creates powerful updrafts, which also moves thermal energy up the atmospheric column
5) when water vapor condenses into clouds it increases the atmospheres albedo and shades the ground
6) when these clouds form water droplets and it starts to rain, snow or hail, this precipitation is nearly always cooler than surface temperatures, which cools the surface even further.
When you combine all of these effects, one observes within weather balloon soundings the predictable, well documented decrease in the troposphere’s temperature lapse rate and this in turn drops ground level air temperatures. Again, this is the inverse of the “greenhouse effect” as defined by Dr. Spencer, which is an “increase in surface temperatures caused by greenhouse gases compared to if those gases did not exist.” Remove water vapor (the most potent “greenhouse gas”) from a climate system and the average yearly temperature goes up.
Dr. Spencer would have noticed this phenomenon and abandoned his belief in the “greenhouse effect” had he expanded his study to include SURFRAD data and weather balloon soundings that were simultaneously being taken in Goodwin Creek, Mississippi. He would have noticed that, indeed, the higher humidity in Mississippi increased the average “down-welling IR radiation” levels by >50 W/m2 24/7. (This, of course, is not surprising since water vapor is known to increase the emissivity of air, which improves its ability to cool the atmosphere.)
What he missed because his study was so limited is the fact that the higher “down-welling IR radiation” levels in Mississippi did not, as the “greenhouse effect” hypothesis predicts, increase surface level temperatures. That is, even though the SURFRAD installations in Mississippi lie a little south of the Desert Rock installation and its altitude is lower, the 2012 average yearly temperature at the Mississippi site was >2 °C lower than at the Nevada site and again, this was in spite of the fact that the “greenhouse gas” water vapor was in greater abundance and the “down-welling IR radiation” readings were significantly higher in Mississippi!
Here is another point to consider. If you read through Dr. Spencer’s article you see his assertion that, contrary to what all weather balloon soundings show, he implies that water vapor, because it is a “greenhouse gas”, increases the temperature lapse rate within the troposphere; he asserts that it causes warming of the lower troposphere and cooling of the upper troposphere. This by default means that he believes that a passive mode of “heat” transport—infrared radiation—decreases the entropy of tropospheric air, which is, of course, a violation of the very laws of physics that he professes to believe in. Here is his statement, “Downwelling IR from the sky continuously maintains surface temperatures well above what they would be without greenhouse gases (while at the same time cooling the upper atmosphere well below what it would be without those gases).”
What he is describing here is an augmentation of the temperature differential that exists between lower and upper tropospheric air, which is a decrease in the troposphere’s entropy. The Second Law of Thermodynamics is not magic. It’s just physics. The Second Law of TD asserts that passive modes of heat transport (such as IR radiation) can only increase entropy and the “entropy” of any body of matter (such as the troposphere) is greatest when it is in a state of isothermia—the same temperature everywhere. Within weather balloon soundings we see that water vapor does, indeed, increases the entropy of tropospheric air in that it decreases the temperature lapse rate and moves the troposphere towards an isothermic state.
Contrary to this observation Dr. Spencer asserts that water vapor, because it is a a “greenhouse gas”, does the exact opposite. He asserts that water vapor increases the temperature differential between the lower and upper troposphere, which again is a decrease in the troposphere’s entropy. Thus his article is not only out of sync with observed reality, it is also out of sync with the laws of physics.
One final point. Dr. Spencer’s article makes a failed attempt at lampooning those who don’t believe in the existence of a radiative “greenhouse effect” by advancing a very common straw-man argument. He states, “the downwelling IR flux is what a few of our friends claim does not exist. They claim that there is no ‘greenhouse effect’, and that the sky (which is almost always colder than the surface) cannot emit IR in the direction of the surface because that would violate the 2nd Law of Thermodynamics.”
As you can see he equates not believing in a radiative “greenhouse effect” with denying the existence of “down-welling IR radiation”. Take another look at this article. At no time and in no place did I deny the existence of “down-welling IR radiation” from the atmosphere. I do concur with Dr. Spencer that “down-welling IR radiation” does not transfer “heat” down the atmospheric column. I also concur with Dr. Spencer that an increase in atmospheric water vapor causes an increase in “down-welling IR radiation”. Specifically I pointed out that the “down-welling IR radiation” in Mississippi was >50 W/m2 higher on average 24/7 than in Nevada because the humidity in Mississippi is much higher.
What I point out though is that in spite of the higher humidity in Mississippi, in spite of the higher level of “down-welling IR radiation” in Mississippi and in spite of the fact that the SURFRAD installation in Mississippi is both lower in altitude and a little further south, the yearly average surface level air temperature at the Mississippi SURFRAD site was measurably lower than at the Nevada site, which is opposite from Dr. Spencer’s definition of the “greenhouse effect” which he says is an “increase in surface temperatures caused by greenhouse gases compared to if those gases did not exist.”
As to this strawman statement from Spencer, from the above:
Dr. Spencer’s article makes a failed attempt at lampooning those who don’t believe in the existence of a radiative “greenhouse effect” by advancing a very common straw-man argument. He states, “the downwelling IR flux is what a few of our friends claim does not exist. They claim that there is no ‘greenhouse effect’, and that the sky (which is almost always colder than the surface) cannot emit IR in the direction of the surface because that would violate the 2nd Law of Thermodynamics.”
we simply have to conclude that Spencer and his cohorts are in fact the climate alarmist establishment itself. Or they’re just really incompetent scientists. They must laugh at us, being political climate alarm supporters, while it takes us so long to catch on to what they’re doing and realize what’s happening. Well, I should say, it was actually figured out what role they’re playing a long time ago, the problem is in figuring out what to do about it, and exposing it, and getting people to care about it.
Roy, here’s the definition of heat flow:
Q’ = σTsurf4 – σTatmo4
The term for the cooler object is right there, right in the equation, on the far right. If you still don’t see it, it is this term: σTatmo4. That’s the cool term. That’s the radiation from the cooler object. And with that term, the heat equation shows that heat only flows from warmer to cooler.
We’ve had this precise discussion with you multiple times. And yet you still create this strawman, this fraud, completely inventing something we did not say, while trying to ridicule the idea of approaching what we do actually say. You do this specifically for the purpose of protecting that precise fraud of the radiative greenhouse effect of climate alarmism, which climate alarmism is based on and which it requires to survive.
The heat flow Q’, from above, is a local transient term, and is not a conserved quantity and does not represent the energy coming from the Sun.
If you and your cohorts know these things, then you’re frauds and clandestine operatives. If you don’t know them, then you’re incompetent.