Guest Post by Willis Eschenbach
If aliens in spaceships saw our world, they wouldn’t name it “Earth”.
They’d name it “Water” because that’s what makes up more than 70% of the surface. And it’s also what controls the climate.
A couple days ago I stumbled across something I’d been trying to find for a while, a longer-term gridded global rainfall dataset. I finally located one at the Copernicus website. It runs from 1979 to December 2021. Here’s the global average rainfall from that site.
Figure 1. Annual average rainfall, 1979-2021
This shows some interesting aspects. The endless rainstorms of the intertropical convergence zone (ITCZ) are seen as the blue band above the Equator. The Pacific Warm Pool is marked by the blue blob of heavy rain north of Australia.
A short digression. The current central paradigm of mainstream climate science is that the change in global temperature is a lagged linear function of the change in total downwelling solar and longwave (thermal) radiation. In other words, forcing (which in the climate world generally means changes in downwelling radiation, hey, don’t blame me, I didn’t invent the term) rules temperature, and everything else averages out.
I hold a different view. I hold that a variety of emergent climate phenomena act in various ways, places, and times to thermoregulate the climate. One of the strongest of these phenomena is the daily emergence of tropical thunderstorms. When ocean temperatures exceed some local limit, thunderstorms form, rain falls, and the surface is cooled. As a result, in the current generally warming climate, we should expect an increase in tropical thunderstorms.
To investigate this prediction, I took a look at the rainfall trends. Figure 2 shows those, in millimeters per decade. Blue is getting wetter, and red is drying.
Figure 2. Rainfall trends, 1° latitude x 1° longitude gridcells.
As my theory would predict, the warming is leading to increased rainfall over the Pacific Warm Pool and around the Intertropical Convergence Zone.
However, the reason that I was looking for the rainfall dataset was not for the rain per se. It was because the rain is a measure of the evaporative cooling of the surface. The global average rainfall is about one meter per year. It takes ~ 80 watts per square meter (W/m2) of radiation over a one year period to evaporate one meter of seawater. In addition, there’s a cooling of another ~ 2.5 W/m2 due to the cold rain falling on the surface.
This means that globally, rainfall directly cools the surface by ~ 82 W/m2.
What I didn’t know until I got the Copernicus rainfall dataset was how that cooling is distributed around the planet. Here’s a view of that. Of course, it looks like Figure 1, only with different units.
Figure 3. Average ongoing cooling from rainfall, 1979-2021
The cooling is centered over the Pacific Warm Pool in the western Pacific. This is the warmest open ocean area. It’s well known that the average temperature of the Pacific Warm Pool never gets warmer than about ~ 30°C … and clearly, the 250+ W/m2 cooling of the warm pool due to rain is among the reasons.
Now, I wanted this information because it is a main part of the effect of clouds on temperature. The other main part is the separate and independent effect of the clouds on total radiation hitting the surface. Clouds warm some parts of the planet and cool others, by a combination of cooling by reflecting sunshine and warming by increased downwelling longwave radiation. Overall, these changes in radiation due to clouds cool the planet by about ~ 20 W/m2. Here’s how that is distributed around the planet.
Figure 3. Average ongoing cooling and warming from the cloud radiative effect, 2000-2023
Note the spatial similarity between the surface cloud radiative effect and the cooling due to the rainfall. No surprise there.
Note also the system’s efficiency—the clouds’ cooling effects (rainfall + radiation) are focused on the warmest areas. And this is true at both the local and the global scale—thunderstorms form preferentially over local surface hot spots. This gives the most cooling for the smallest effort.
Adding these two different cloud effects together gives us a measure of most of the effect of clouds on the surface temperature. I say “most of” because there are some other cooling effects. These include:
- Snow, sleet, hail, and graupel. Since these are frozen, there’s additional surface cooling from the melting of the ice.
- Clear dry descending air around thunderstorms. Because most of the water as well as most of the aerosols have been stripped out of the air by rainfall, there’s far less water vapor and aerosols to absorb radiation leaving the surface. This allows for greater surface radiation making it to space, cooling the surface.
- A cold wind from the condensation level of the atmosphere is entrained by the falling rain and hits the surface vertically. This wind then spreads out when it hits the surface, cooling a much larger surface area around each rain cloud.
Setting those other cooling effects aside for the moment, here’s the distribution of total cloud cooling (radiative plus rainfall) around the planet.
Figure 4. Full effect of clouds on the surface temperature
Note that rather than the ~ -20 W/m2 cooling from just the radiative effects of the clouds, the true effect of the clouds is about 100 W/m2, and there are large areas where the cooling exceeds -300 W/m2.
Next, we can take a look at the relationship between total cloud cooling (radiative plus rainfall) and surface temperature. This is clearest over the 70% of the surface that is water. Here’s that relationship.
Figure 5. Scatterplot, total cloud cooling (rainfall plus radiation) versus sea surface temperature. Each blue dot is a 1° latitude by 1° longitude area of the ocean surface.
This is exactly the shape we’d expect to see in a thermoregulatory system. As the sea surface temperature increases, the total cloud cooling reduces … but only up to about 26°C. Above that, the cloud cooling increases very rapidly, quickly becoming around -300 to -400 W/m2 of cooling as the sea surface temperature gets up close to ~ 30°C.
Now, the yellow line in Figure 5 shows the slope of the cloud cooling/temperature relationship, which is how much the cloud cooling changes for every 1°C of surface warming. And over at the right of Figure 5, that slope is ~ -100 to ~ -150 W/m2 of increased cooling for every 1°C of surface warming.
In closing, let me note that since 1950, CO2 has theoretically increased downwelling radiation by something on the order of 1.4 W/m2 … and that would be totally undone by a mere 1.4% increase in cloud cooling. In that context, bear in mind that global cloud cooling changes by up to 9% from one month to the next, and we never even notice …
[CODA] The important thing about cloud cooling is that it is temperature-controlled. It has nothing to do with forcing. When tropical sea surface temperatures go above about 26°C, it rains, regardless of the forcing. Period. See below.
Figure 6. Pacific equatorial rainfall, 5° north to 5° south.
My regards to all, and remember—rather than cursing the storm, learn to dance in the rain …
w.
As Always: Please quote the exact words you are discussing. It avoids endless arguments. And me, I’m going to be in town today when this publishes, so play fair, no eye gouging, and may the best wo/man win …
Just a small but key factoid from my WIP book that offers a measurement based empirical model of the Earth energy balance system, because the average SST is determined by whatever it needs to be to balance radiation in with radiation out. But don’t tell modellers in their fairy tale VR land, they have NO idea how the whole system works, because they’re paid to ignore the larger holistic reality and prove CO2 from combustion causes runaway warming. Not really, but that’s what they’re paid to say. We can hunt them down when the truth finally dawns on Joe Public…..
The largest single negative feedback to any anomaly in the radiative energy balance is caused by the SST response that changes the current total of 86.4W/m^2 of latent heat transferred from the oceans to condense and form clouds and water droplets in theTropshere, raised up by the 18.4W/m^2 of convective heat transfer that varies little (with absolute temperature?) but does the heavy lifting work for the water vapour. The adiabatic convective equilibrium of the Lapse rate that Maxwell described about 160 years ago(as dominant). The condensation releases the latent heat as creates LWIR that is lost to space, as is the other radiation leaving the surface directly to through the atmosphere, scattered or not. So the heat flux is rebalanced,also aided by other negative g feedbacks, but this is the biggest response wise, per deg change.
HERE IS THE THING, that nobody mentions, when debating the theoretical amplification of AGW perturbation to the energy balance by GHE from the extra water vapour that must result froma warming perturbation ….. the MUCH LARGER negative feedback of the evaporative cooling by water vapour and subsequent radiative loss to space increases by 7% per degree K (in the average range of SST temperature and RHI that applies). nb: It doesn’t go back down in the rain FFS,a nonsense asserted to me by people who I thought understood Thermodynamics 101. EVEN NASA understands this, its part of the 240W/M m^2 in their energy balance diagram. It’s just the muddlers are too stupid to even break that simple energy balance down for themselves.
So the NEGATIVE feedback to 1 deg of change in STT from latent heat of evaporation, radiated to space from the troposphere, is 6W/m^2 per deg K. That’s absolutely clear and must happen, give or take a few % of 6W/m^2. But nobody says. I wonder why not? It’s right there in the NASA energy balance for anyone numerate to see, and add to the negative feedback of 3.3W/m^2 per deg K of the Stefan Boltzmann effect.
So that’s 9.3W/m^2 negative feedback, without any negative cloud feedback.
NB: Per NASA, of the 240W/m^2 of solar energy absorbed by the whole Earth energy balance system, 163 reach the surface, 77 are absorbed in the atmosphere. Of the 163 re-radiated from the surface, mostly from the ocean which has evapoartion to add to radiation, 86.4 is evaporative latent heat, 18.4 the convective transport and 57.9 is radiated direct from the surface as LWIR, of this 41 is. passes directly to space and 17.9 is scaterred by GHE, 2/3 of that by water vapour and 1/3 CO2. Roughly. Check it out. Yoi can ignore the lossles scattering, whch has no net effect on the rngy transfer, except indirectly by the frequency related additional atmospheric insulation effect it creates.
AS Willis started out, the 71% Oceans control the climate on Earth, with evaporative and radiative cooling, and also with 67% Clouds as above. Which maintain energy equilibrium in space.
What is controlled is not temperature, it’s the energy equilibrium in space, which is imposed by nature at whatever SST that needs it to be to vary the radiation loss to space and hence maintain the energy balance, at whatever energy level that is, in response to either external or internal perturbations to the whole Earth system.
Attributing all temperature change to the much smaller atmospheric effects of AGW, made up in models, created to pre-determined political agenda that exclude the dominant controls by presumption – so they can attribute all change to their chosen cause, is not even a clever lie, in the self evident truth of the natural feedbacks. Sadly most people are too stupid to understand or too lazy to check the facts on the physics they were taught at school, so repeat the lie from authority.
ALSO, With 99% of Earth’s surface heat capacity and >96% of all the stored surface energy in the oceans, the land has sod all to do with global climate Why do people bother talking about weather on land as if it represents global climate? It obviously can’t, pre High School Physics says NO. Melting ice in water and putting hot solids in beakers of water. Remember thermal capacity?
Weather on land is an infantile distraction from the realities of oceanic global climate over 30 years. Used to find extremes that affect a tiny area where people live, or nobody lives so no one can check, to scare the ignorant. IMO E&OE
Congratulations Willis. Very good paper. You’re finally getting to the nub of the matter.
I would like to make 3 comments to extend your analysis.
Firstly, I would like to discuss the mechanism of the evaporative (cloud) cooling feedback that you provide in Figure 5, 100 – 150 W/m2 of additional cooling per degree C of additional temperature above 26 C.
This level of feedback far surpasses what could be expected if it was due uniquely to the vapor pressure of water. The vapor pressure of water doubles for every 10 C, so if this effect was only due to the vapor pressure of water, we would expect that this feedback would be of the order of 10 W/M2-C.
The order of magnitude higher feedback is due to the secondary affects of additional water vapor in the air. Water vapor is 40% less dense than dry air. When evaporation rates become sufficiently high, the density differences caused by the additional water vapor begin to cause winds to increase. When winds increase, the mass transfer coefficient increases proportionally causing additional evaporation in a self-reinforcing feedback loop. If the winds increase enough to cause waves with broken surfaces, then the surface area for evaporation increases dramatically, with a proportional dramatic increase in evaporation rates.
It is these secondary effects of additional water vapor in the air that are the cause of the very high evaporative cooling feedback rates that you present in Figure 5. The important thing to note is that these secondary effects are mechanical in nature.
Comment 2:
I would now like to discuss how the high evaporative cooling feed back rates from Figure 5 affect ENSO.
According to the earth’s energy budget, the average solar energy incident upon the earth is about 340 W/m2, and the average evaporative cooling is about 85 W/m2. However in the tropics, due to geometry, the solar energy incident upon the earth will be П/2 times this value or about 540 W/M2, and the evaporative cooling required to balance the heat input would need to be somewhere between 150 and 250 W/m2.
According to Figure 5, at 25 C, evaporative cooling is about 80 W/m2 (neglecting the 20 W/m2 from cloud reflection). While at 30 C evaporative cooling is close to 500 W/m2 C. Thus tropical ocean surface temperatures of 25 C are inherently unstable because there is not enough evaporative cooling, while tropical ocean surface temperatures of 30 C are inherently unstable because there is too much surface cooling.
It is no coincidence that Nino34 temperatures oscillate in precisely this temperature range, 24C to 29C. This shows that ENSO is an oscillation between two inherently unstable conditions, when the temperature is at the lower end, there is too little cooling to balance the energy input, while at the upper end of the temperature range there is too much cooling.
According to Figure 5, at the average Nino34 temperature, about 27 C, the system would have the right amount of cooling, about 200 W/m2. But it attains this average by oscillating between the two extremes. And the reason for this oscillation is, as I discussed in my first comment, due to the hysteresis in the system caused by the fact that the the mechanism for transferring from a low to a high cooling state is primarily mechanical, requiring to put into motion a tremendous mass of air and sea.
Thus ENSO is, in essence, an oscillation between two unstable states in which temperature equilibrium is rarely achieved due to the tremendous hysteresis of the system. The typical ENSO cycle time of 3.5 to 4 years reflects this hysteresis
Comment 3
A third comment that I would like to make is about the tremendous power of evaporative cooling, as you show in Figure 5, some 100 – 150 W/M2-C. Evaporative cooling from the tropics, and particularly ENSO, truly regulates the earth’s climate as a whole.
Yet, in spite of this tremendous power, it is still possible to see the imprint of the solar cycle on ENSO. And that reflects only the effect of the solar cycle on the tropics.
The effect of solar activity in extra-tropical oceans on ENSO will only be seen once the extra energy, stored in the oceans, is transferred to the tropical Pacific on via ocean currents, a process that can take decades. And indeed, we can see variations in decadal averages of Nino34 of up to 0.6 C from the lows of the 1890s to the highs of the 1990s, which, according to Figure 5, would reflect decadal changes in evaporative cooling in the Nino34 area of more than 50 W/m2.
It appears to me that, in today’s climate science, the effect of solar activity on the earth’s climate is vastly underappreciated.
rather than cursing the storm, learn to dance in the rain …
Yep
“downwelling solar and longwave (thermal) radiation”
Now that we have established conclusively that radiation is energy, why would you write “CO2 has theoretically increased downwelling radiation by something on the order of 1.4 W/m^2” ? You told us that energy is the capacity to do work, therefore radiation is also the capacity to do work, and we measure that in Joules, not Watts. Right?
Willis, great find and analysis!
what would the increase in corresponding ocean surface temperature be and how does it compare to the measured increase?
A neat graph would be to show what that 1.4% looks like in terms of cloud changes.
Willis
Excellent article showing how water vapor distributes energy, heat, temperature, clouds around the globe.
As described above, it seems to me that variable hydrology (evaporation, convection, condensation) has everything to do with the temperature of the “Globe” and CO2 is just an “onlooker” The enthalpy of evaporation, condensation, solidification, fusion, liquefaction releasing/absorbing quadrillions – quintillions of Jules of energy as these rivers of water move around the Globe and are completely ignored in the “FAKE” Climate Models.
Hi Willis, as I pointed out in your last thread the function you astutely fitted to climate models is not a lag. It is an exponentially weight integral. So the lag is phase change. It also has low pass filter (smoothing) characteristics.
Your formula is a recursive filter implementation of an exponentially decaying integration.
It also models a linear negative feedback : ie the more the deviation from steady state the stronger the corrective feedback will be.
It is basically like the model of cooling of a pot of hot water. First it cools quickly, then less so.
This in no way counters your observation but it useful to understand physics of what you found. Although an integral introduces a lag, it is a frequency dependent lag: a phase change.
There would not be much physical justification for a simple fixed lag but it is equally damning if all the gargantuan climate models are doing is modelling a pot of water cooling.
Well the “forcing” (stupid term) is radiative power flux, so temperature is the time integral of the “forcing”. Not really “nothing to do with”.
Again this gets back to the need to see you simple replacement of climate models as an exponentially weight average. It is the time integral of “forcing” with a linear negative feedback applied.
This is not inconsistent with you self-regulation hypothesis: the storms are the negative f/b.
Thanks for the post. Always good have the data.
Willis,
Can you produce this as document that can be downloaded from somewhere. And referenced. It is a very useful way of looking at things with detailed evidence.
I am doing my effort as a Book with less complexity but obvious empirical engineering rigour, so more people can get the big picture about what goes in and what comes out, which must always be in balance in space. The actual control. There is no thermostat, there is an energy stat.
The complecity, of course, i comes from how the transfer within the system is shaken all about in the atmosphere, between the surface and Tropopause, mainly by the evaporative oceans which deliver the largest and most sensitive/responsive and largest feedback per deg of SST. And you can add cloud albedo to the latent heat transfer that create them, as you describe.
There are really only a few simple controlling concepts to be conveyed here, in plain engineering speak. That is our challenge, and which will be my main objective. Probably needing several re writes.
And I have avoided all the distorted and deceitful languags of climate pseud science, to prefer basic scientific language. I try to avoid the liars language. Because it was designed to confuse and distract from the climate ology reality we knew before their religious science was invented.
I would like to refer to your work as regards the energy in clouds, and its variabiity. MASSIVE.
BTW, not that it changes your point I disagree with your statement regarding downwelling forcing increasing on its own as the claimed cause of climate change. Not what I have read or seen presented. And hence it may distract from the important realites you describe.
THUS: The energy balance with space is what is maintined, so actual LWIR leaving matches Solar EMR absorbed (I ignored albedo of clouds there, of course it also matters). BUT the GHE change due to CO2 simply increases the scattered radiation BOTH UP AND DOWN at the CO2 GHE frequency, it “wells” all over the place, 4pi wards.
That means less of that CO2 GHE scattering frequency eventually escapes from the troposphere to space, because Stefan Boltzmann temperature effect, etc.. Which is the real warming effect of GHE. Its transparent insulator with zero heat capacity. The stored energy in the excited GHGs is not available to heat the atmosphere, it is lost as radiative energy to space, nor is the molecular binding energy of water vapour that is latent heat. I suggest.
Neither heat or cool the planetary system directly, the evaporative latent heat transfer cools it, the GHE scattering warms it, both through indirect consequences.
The warming from GHEs is because SSTs must increase naturally, at the mainly ocean surface, to increase radiative losses to space that rebalance the whole Earth energy system, from the two main radiative negative feedbacks, evaporation & S-B radiation, PLUS cloud albedo can be added here as significant, that reduces the amount of solar energy absorbed by the whole earth system, so the net cloud effect, if net negative feedback when the warming effect at night is considered, means less LWIR loss is required to rebalance the system – hence a smaller SST change for the evaporative and S-B cooling response .
That is the control system language I will try to stick to, because its simple and requires no Latin Bible to confuse ordinary folk with some grasp of engineering realities by making the simple complicated, an changing the meanings when it suits the priests.
The results of all this are plainly seen in MODTRAN, once you grasp what is going on in full. The OLR energy is beneath the 260 K line because of GHE and above it through the radiation coming direct from the surface at 288 K, etc..
AGAIN, and as I understand the science, the GHE has no direct warming effect in this, it is lossless quantum scattering by excitation and relaxation of molecular binding modes in CO2. Per the generally accepted description. Probably
PS Have you read Peter Ridd’s paper on tropical storm energy? It may be of interest, you may have included it in your thoughts already. It certainly explains what is dominant in Earths thermal energy balance and what is not.
https://climatechangethefacts.org.au/wp-content/uploads/2021/08/CCTF-fact-sheet-12-Tropical-Convection-Cooling-the-Atmosphere-V1-2.pdf
Just as a general credit to JC Maxwell, he got the massive energy flows associated with water and water vapour on Earth’s surface at the end of the 19th Century, not the small effect of CO2, but the dominant energy transfers created by adiabatic convection of evaporating oceans, and he pointed this out qualitatively to Thompson/Lord Kelvin, a less able man who nevertheless had ideas. But they could debate them back then, when real science was still done.
Still wrong.
