Climate Letter #2015

There is a simple solution to the problem I have been writing about, which will preserve the primary substance of Carl’s theory. I will just stop calling the effect of precipitable water (PW) a greenhouse energy effect—and not even a plain greenhouse effect, which might create a false impression. I will do the same thing scientists do, and call it a surface warming effect. Scientists regularly talk about cloud cover having a noticeable warming effect on the surface apart from the cooling effect of surface albedo. Cloud warming is not commonly referred to as a greenhouse effect, and as a rule there is no attempt made to offer a detailed alternative explanation for the warming. I should be justified in calling the PW outcome a warming effect without even mentioning the physics, and nothing important will be changed within the theory.

My theory, to begin with, is not about cloud cover. It only refers to PW, which is a more complex kind of material. I don’t think you will find any other references, anywhere, to the warming effect of PW as such. I only happened to land on it as something worth looking at because it is being so accurately measured all the time on a basis of multiple locations. That, plus of course my ordinary realization that PW in its entirety contains all of the water vapor in the atmosphere and all of the matter that has been temporarily condensed into clouds. The fact that it contains other materials as well—in more advanced states of condensation—did not seem critical. PW, specifically attributed to the atmosphere as it exists over any given location, carried the promise of generating all of the actual greenhouse energy effect due to whatever amount of water vapor it contained at that location plus the total warming effect of whatever amount of material had been made up in the form of clouds above the same location. Both of these effects are by definition realized at the surface, in the form of departures from whatever temperatures at the surface would be reported in their absence. Each effect causes warming, so why would their separate effects not be combinable into one total amount of warming for that location?

The temperature “anomalies” that attract our attention are seldom expressed as departures from point of no effect.  We always look for departures from whatever the average was during some convenient baseline period where averages could be ascertained within reason.  This is done in many different ways, with varying degrees of accuracy.  We are fortunate to have a solid baseline set up for daily average temperatures, over a 20-year period, covering a bountiful array of individual locations which include the most remote parts of the planet’s surface, very accurately measured through 24-hour days.  On each new day we receive a map showing the current departures from average, reasonably condensed, over virtually every bit of the entire surface.  Absolutely priceless, if you know what to do with it.  What I have been doing with it is very simple.  I have another map of precisely the same shape and dimensions showing the total weight of the H20 molecules in a vertical column of air over any selected location for that same day.  The given values vary over an incredibly wide range, starting at “under 1kg” and running up to practical limits of around 80kg.  Go to https://climatereanalyzer.org/wx/DailySummary/#t2max at any time and see these for yourself.

The PW values that come up each day for any one location show a surprising amount of variation.  They are generally on the numerical high side for tropical locations and lowest in the polar regions, with fairly steady rates of decline in between.  Individual locations at any one latitude, on land, will also vary considerably by elevation, with lowest kg values at the highest elevations. All individual locations are marked by a range of kg values, some wider than others, with some making wide daily changes and in all cases seasonal.  In nearly every case, when kg values are observed near the high end of the range for a particular location the daily temperature will be relatively higher than when values are lower.  One thing is missing that we might wish for, and that is a daily baseline average for the PW value at each location, comparable in practicality to the ones we are now getting that reveal temperature anomalies.  The temperature and PW anomalies could then be matched up on the widest possible scale with the least amount of guesswork.  This is well beyond my reach but could be accomplished with an organized effort.

What kind of result do I think would be most likely?  Relying only on estimates of baseline averages for PW, Carl’s theory was formulated on the basis of observations that, outside of the tropical belt, and after adjusting for other factors known to cause temperature changes, any observed doubling of PW value for a given location, on a given day of the year, would cause a temperature increase of close to 10C at the planetary surface, attributed to the combined greenhouse and warming effects of the water vapor and clouds contained in the overhead column of PW.  The actual proportion of each, which I can be aware of but cannot closely estimate, has not seemed to make a significant difference in the outcome.  This perceived outcome, if at all accurate, would suggest that the warming power of clouds, weight for weight, is practically the same as the greenhouse energy effect of water vapor alone. As an added note, the skies that have PW values are often cloudless.  The perceived outcome also gives us a new way of calculating the climate-warming power of water vapor on a long-term basis, well beyond the limitations of daily anomalies, when tied to overall projected future increases of any incremental value—no matter how much cloud cover was being carried. The cooling effect of cloud cover albedo, serving as a powerful offset, would still need to be measured and calculated independently, and should continue to be studied on that basis.  

Carl