Total Precipitable Water and the Greenhouse Effect

Global relative humidity in the upper atmosphere has generally been declining since
1970, but the there has been a recent increase since 2010 at the 300 and 400 mbar levels.
Total precipitable water is an important climate parameter as it is a measure of the total amount of water vapor in the atmosphere, which is the most important greenhouse gas.

Water vapor increases with global warming and in the climate models it amplifies the direct small warming caused by anthropogenic greenhouse gas emissions.

The greenhouse effect is much more sensitive to water vapor in the upper atmosphere than near the surface.

As seen in the graph above, this article shows that declining humidity in the upper atmosphere fully offsets the greenhouse effect of increasing humidity in the lower atmosphere.

Eliminating the water vapor feedbacks from climate models would reduce the multi-model mean equilibrium climate sensitivity from 3.2 °C to 1.7°C and would reduce the social cost of carbon dioxide calculated by the FUND economic model, with two updates, from 2018US$‑1.79/tCO2 to US$-7.14/tCO2at 3% discount rate.

The negative signs indicate that climate change is beneficial.

Note that there are other serious problems with the climate models that exaggerate climate sensitivity. The climate models fail to consider the urban heat island effect (UHIE), which contaminates the surface temperature record, and natural climate change from ocean oscillations and solar activity, which are falsely attributed to greenhouse gas warming.
5 1 vote
Article Rating
Newest Most Voted
Inline Feedbacks
View all comments
Phil Salmon
September 29, 2020 10:42 pm

Here’s another article that says essentially the same as what Ken Gregory is saying – that declining relative humidity is cancelling CO2 warming:

In the 1948-2008 time period the global average annual mean true greenhouse-gas optical thickness is found to be time-stationary.

Rob JM
Reply to  Phil Salmon
September 30, 2020 2:57 am

Increased convection appears to dry out the upper atmosphere, while also bypassing the strong insulating properties of the lower atmosphere.

Reply to  Phil Salmon
September 30, 2020 3:31 am

The temperatures have risen almost 1°C over the period of Dr Roy Spencer’s satellite derived temperature record. If you are saying that this is not due to water vapour then CO2 must be having a more serious effect.
Of course if you look at surface warming we are already over 1°C.

You will probably say the rise is due to natural cycles that have always happened, in which case you should also be able to say what causes these natural cycles.

D. J. Hawkins
Reply to  Ghalfrunt.
September 30, 2020 4:59 am

No, there is no need to justify or explain natural cycles. It is up to the alarmists to explain exactly how today is different from yesterday, when all the effects we’ve seen have been seen before. In fact, long before. The land surface temperature increase from ~1910 to 1940 is nearly the same as ~1975 to 2005. The IPCC says anthropogenic CO2 was negligible before 1950. Explain why the former doesn’t matter and the later requires “climate action”.

Robert W. Turner
Reply to  D. J. Hawkins
September 30, 2020 5:57 am

Haven’t they adjusted away the 1910-1940 temperature rise?

Reply to  Robert W. Turner
September 30, 2020 8:07 am

No, they just try to hide it by dumping mutliple modelled lines all over it and hoping in the resulting confusion, no one notices that NOT ONE of them captures the actual rise in temperature.

BTW, I thought that one of the basic assumptions of all models was that RH is some immutable constant and that this is then used to create more WV and thus the spurious claims of doubling the actual calculated warming of CO2.

Reply to  D. J. Hawkins
September 30, 2020 7:52 am

But 4 billion years ago temperatures were 2000°C and 635million years ago the average temperatures were -20°C and you missed these important cycles.
Now why not publish your plot of world temps with -40 to +2000°C y-axis (instead of the usual -40 to +50°C) to show how insignificant the winter summer differences are?

You say “there is no need to justify or explain natural cycles” – of course not you are totally unable to do so. There is no way any climate scientist can explain the GH effect to you as you will always claim FAKE SCIENCE.

D. J. Hawkins
Reply to  Ghalfrunt.
September 30, 2020 8:53 am

I see you have unwisely decided to play both the “strawman argument” card and “invincible ignorance” card in the same hand. Not a winning combination. I showed you two instances of similar temperature increases, one before anthropogenic CO2 was deemed significant and one after. That’s my evidence. Explain how one is natural and the other a climate emergency. Good luck.

Phil Salmon 🍣
Reply to  Ghalfrunt.
September 30, 2020 3:17 pm

Your comment reveals your ignorance of and contempt for earth’s history. To become an activist you have to first kill your curiosity.

Reply to  D. J. Hawkins
September 30, 2020 4:10 pm

Ghalfrunt: You need to understand why your argument is invalid – it is the logical fallacy of superstitious thinking. It is the same logical fallacy used in times past to burn witches. The witch caused our crops to fail. Burn the witch. Then to any counter-argument, comes: If you can’t explain why the crop failed then we will burn the witch.
The logical fallacy of superstitious thinking / magical thinking occurs when a belief does not follow from real evidence.

David A
Reply to  Ghalfrunt.
September 30, 2020 5:00 am

Chal… way to simplistic
SW solar insolation
The oceans which overturn on a thousand year timescale.
Cloud cover flux.
Faulty computer drivenThermometer records

Bill Toland
Reply to  Ghalfrunt.
September 30, 2020 5:18 am

Ghalfrunt, the warming trend in the UAH temperature record is 0.14C per decade since inception which comes to just over half a degree. Have you ever posted anything on this site which is not misleading in some way?

Robert W. Turner
Reply to  Ghalfrunt.
September 30, 2020 5:55 am

Yeah, ocean oscillations and the sun. That was easy.

Richard M
Reply to  Ghalfrunt.
September 30, 2020 6:02 am

Ghalfrunt, your math is faulty. Roy show .135 C / decade for 4 decades. That comes to .54 C. Not even close 1 C. Add in that natural ENSO cycles and placement of major volcanic eruptions have added to that trend.

Finally, the AMO and PDO have been in the positive phases for 75-80% of the satellite period also increasing the trend. When everything is considered you cannot show any climate change outside natural variation.

Ian Bryce
Reply to  Ghalfrunt.
September 30, 2020 6:23 am

The increases happen when there are super El Nino events. It is not due to CO2.
See Bob Tisdale’s blogs on this, and why it is so.

Reply to  Ghalfrunt.
September 30, 2020 6:26 am

“…. in which case you should also be able to say what causes these natural cycles…..”

An interesting question you ask, so presumably you can answer the following basic questions:

What caused the ice ages
What caused them to end?
What caused the Medieval Warm Period?
What caused the Medieval Warm Period to end?
What caused the drastic changes of climate – ice ages to warming to ice ages and back again to warming, etc – that earth has experienced well before humans had any affect on the climate. ??

So here’s your chance to show us all that you really understand what drives climate.
Go for it.
Oh, and while your at it, please explain the below average (ie. colder temperature) 25 year period (1940 to 1975 +/-) where climate scientists proclaimed with great certainty a new ice age, despite CO2 levels that steadily rose since 1900.
Just how is it possible to have this cold period even though CO2 levels were higher than the real hot Dust Bowl days of the 1930s?
I realize you have the answer to this question as well.

I am still waiting to view that 1000′ thick sheet of ice from my window. Perhaps if I go to Lower Manhattan (did you know that lower Manhattan was supposed to be 10 feet under water by now) I will get to see these massive ice sheets.

Oh, by the way, today’s climate is totally average , totally normal, when looking at the variations in the climate over the last, say 5000 years or so, despite the steady increase of CO2 over the last 100 years or so. So it appears that elevated CO2 – based on some randomly chosen base point – is not having your desired affect.
But I am sure you can explain that as well.

Go for it.

Phil Salmon
Reply to  Ghalfrunt.
September 30, 2020 3:11 pm

, in which case you should also be able to say what causes these natural cycles.

I can say, thanks.
It’s the entrainment from high to lower dimensionality of chaos-turbulence and associated emergence of spatiotemporal dissipative structures, caused by internal feedbacks and external periodic forcing. Exporting entropy in the process. That’s the answer you were looking for I assume?

Reply to  Ghalfrunt.
October 1, 2020 7:01 am

Hey it’s Ghalfrunt who recommends drinking bleach…shame on you.

Reply to  Phil Salmon
September 30, 2020 5:14 am

I get your logic.
So , for instance, what if we don’t know the exact mechanism for switching between glacials and interclagials in the last 3 million years, including how the time interval changed from 40,000 to 100, 000 years, 1 million years ago (mid Pleistocene revolution)?
Don’t know the mechanism?
Then we stop believing in the existence of ice ages? Because we don’t know all the mechanisms?

Do we know the mechanism for human consciousness.
Then let’s stop believing in that too.

Don’t know the mechanism for the big bang? That’s fine – then nothing exists.

Signed up to post-modern science.

September 29, 2020 11:19 pm

“Water vapor increases with global warming and in the climate models it amplifies the direct small warming caused by anthropogenic greenhouse gas emissions.”

When water evaporate both the water surface and the air drops in temperature. This is well known, we build air-coolers on this principle: swamp coolers/evaporative coolers.

How the f**k did anyone get the idea that evaporation of water warms the planet? The net effect of water vapor is much lower air temperature. Why does the greenhouse theory consistently make claims that is the opposite to proven and widely applied physics?

Zig Zag Wanderer
Reply to  lifeisthermal
September 29, 2020 11:57 pm

Exactly my thoughts.

Also, if this were true, any warming, for any reason, world result in runaway warming in a vicious feedback loop.

It doesn’t. It never has. Theory completely disproved.

Reply to  Zig Zag Wanderer
September 30, 2020 12:59 am

Water cools a hot planet. How could it be otherwise?

Reply to  Chaswarnertoo
September 30, 2020 3:35 am

Cripes people. Where do you think the heat from your swamp cooler goes. The only way evaporation can cool a planet is if it somehow allows more radiation to escape to space. Evaporation will cool the local environment but it transfers the energy elsewhere making “elsewhere” hotter.

Reply to  Ghalfrunt.
September 30, 2020 4:39 am


Yep, that’s why clouds exist.. !

What do you think happens to the hotter moist air ?

Perhaps look up the word “convection” to get a basic junior high understanding . !

Reply to  Ghalfrunt.
September 30, 2020 4:52 am

Water evaporates to the air taking heat from the water itself. Water vapor with the “new heat” rises in the atmosphere and condenses high up giving up the “new heat” in the process. “New heat” radiates into outer space. Problem solved.

Reply to  Ghalfrunt.
September 30, 2020 4:54 am

Dear G,

2 things, first off more evaporation means more clouds and clouds prevent radiation from reaching the surface.
Second as water vapor rises it indeed makes ‘elsewhere’ hotter. As this elsewhere is now above most of the atmosphere it can radiate more easily to space and thereby cool the planet.


D. J. Hawkins
Reply to  Ghalfrunt.
September 30, 2020 5:05 am

Convection carries the water vapor to the upper troposphere where is condenses and the heat is more easily radiated to space. Cripes, don’t you know how the water cycle works?

Alasdair Fairbairn
Reply to  D. J. Hawkins
September 30, 2020 5:16 am

D.J. Hawkins
NO. It is the inherent buoyancy of water vapor that carries it up through the atmosphere. Convection plays its part; but is not the prime influence. The two are very different in the way they operate with the buoyancy being independent of temperature differential.
I note that this aspect never gets mentioned in the articles and reports whether alarmist or sceptical and the two get conflated under just the term convection. I makes me despair.

Alasdair Fairbairn
Reply to  D. J. Hawkins
September 30, 2020 5:43 am

D.J. Hawkins:
True; but it is the BUOYANCY of water vapor that carries it up through the clouds and those cirrus ones nudging the tropopause which radiate into space as the crystals grow.

Alasdair Fairbairn
Reply to  Ghalfrunt.
September 30, 2020 5:28 am

This doesn’t necessarily make things hotter as you claim. The condensation process takes place at CONSTANT temperature with a Planck sensitivity coefficient of Zero. A lot of the energy lost from the Latent Heat goes to increase potential energy as the vapor is driven up through the atmosphere through its buoyancy with respect to dry air.
How else do you think all those tonnes of water get up into the clouds?
It is not done by magic.

Wim Röst
Reply to  Ghalfrunt.
September 30, 2020 5:58 am

Ghalfrunt. September 30, 2020 at 3:35 am
“Evaporation will cool the local environment but it transfers the energy elsewhere making “elsewhere” hotter.”

WR: Evaporation cools the surface that is where we live and where we measure temperatures. The energy is transported upwards by convection where it diminishes the cooling at those higher elevations (not: ‘making things “hotter”‘) From those higher elevations (containing but a small quantity of absorbing H2O molecules) the energy that was absorbed near the surface or was surface released as latent heat can escape to space. Because of our thick (water vapor rich) greenhouse atmosphere near the surface space ward radiation from below was not possible: that has to happen above in the atmosphere. Convection is the transporter.

Convection stimulated by the same water vapor is a surface (!) cooling system. The high rising water vapor columns dry the air in colder circumstances high in the air and over many latitudes drier air is descending, enabling more space ward radiation. This is the cooling system of the tropics/Earth. That cooling is stimulated by…… warming.

The graphic above in the article shows the result of the drying of air at higher elevations as happens by a stimulated convection. In the narrow stimulated convective column you will find more water vapor but over many latitudes north and south of the equator less humid air descends. On average the RH goes down as result of convective cooling.

Robert W. Turner
Reply to  Ghalfrunt.
September 30, 2020 6:02 am

And not to mention, that when you properly consider conductive heat transfer from very low absorbing/emitting N2 and O2 – which comprises the vast majority of atmosphere – to much higher absorbing/emitting “greenhouse gases” like water vapor, the net effect is obviously cooling.

Reply to  Ghalfrunt.
September 30, 2020 7:39 am

Cripes person, have you never heard of what happens to warm, humid air?
It rises. When it gets high enough, the evaporated water condenses, releasing it’s heat.
However, the higher in the atmosphere it gets, the easier it is to radiate that heat into space.

This is first year meteorology stuff.

Reply to  Ghalfrunt.
October 1, 2020 12:22 am

Newsflash, Galfrunt temperature is not the same as energy. Energy can be added to a closed system w/o increasing temperature. The opposite is also true. The energy doesn’t have to be transferred only converted since cooling is measured by temperature which is NOT a unit of energy. No laws of physics are broken. Think endothermic reaction for example.

D. J. Hawkins
Reply to  Chaswarnertoo
September 30, 2020 8:59 am

@Alasdair Fairbairn

Do you understand that convection is driven by buoyancy? That the three heat transport mechanisms are conduction, convection, and radiation?

the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.

Alasdair Fairbairn
Reply to  D. J. Hawkins
September 30, 2020 11:03 am

Yes. I am aware; but as you rightly point out convection depends on the temperature difference to drive it; so creating a buoyancy. The Buoyancy I refer to is a different process and is independent of temperature differential. It stems from the relative molecular weights between, in the case of water, H2O and that of dry air. (18 to 29). This is rarely if ever referred to in the literature where the two get conflated, which IMO often confuses the logic.
A case in point is in the anvil type cumulus clouds where an inversion apparently stops the cloud rising; but in fact the vapor in the cloud, which we cannot see, still rises due to its inherent buoyancy…

Phils Dad
Reply to  D. J. Hawkins
September 30, 2020 8:08 pm

The Incredible Lightness of Water Vapor
Da Yang; Seth D. Seidel
J. Climate (2020) 33 (7): 2841–2851.

It is possible for (slightly) colder water vapour to rise in warm air. This is because of the relative density at the molecular level between different materials (dry air and gaseous water) and not the (heat caused) density difference of the same molecules in dry air.

Either way more water vapour in the atmosphere leads to overall cooling; according to the paper above in sufficient amounts to counter the “greenhouse effect”.

Alasdair Fairbairn
Reply to  Phils Dad
October 1, 2020 3:09 am

Phil’s Dad:
Absolutely YES. This molecular derived buoyancy is fundamental in the Hydro Cycle and often gets conflated with convection. The two are very different as this inherent buoyancy is independent of temperature difference and thus enables the water vapor(gas) to rise through the atmosphere in spite of variations in the lapse rate such as inversions etc.
You can see this in those anvil shaped cumulus clouds apparently cut off by an inversion. But in fact the vapor continues to rise but invisible to our eyes.
We only see about half of a cloud for all we see are the water droplets but the cloud is full of vapor which is invisible. The vapor tends to rise and the droplets to fall giving a balance which makes the cloud appear to be static, there hanging in the air.
Someone should tell the IPCC about this. Seems it is a bit confused about clouds.

Reply to  Zig Zag Wanderer
September 30, 2020 3:45 am

Exactly, there are positive (evaporation) and negative feedbacks (precipitation) of the atmospheric water vapour, which over ta medium time period neutralise each other.

Michael Jankowski
Reply to  Zig Zag Wanderer
September 30, 2020 5:02 pm

Why does a feedback loop have to result in runaway warming? Why can’t there be diminishing returns until it hits a max? Why can’t other feedbacks counter-balance it eventually?

Alasdair Fairbairn
Reply to  Michael Jankowski
October 1, 2020 3:59 am

Well they do. Water being the main negative feedback here. In fact it swamps the GHE.
By ignoring this the IPCC has generated a major and fundamental FLAW in its overall logic.

Matthew Sykes
Reply to  lifeisthermal
September 30, 2020 12:13 am

It takes 5.5 times as much energy to evaporate water as raise from 0 C to 100 C

Latent heat loss is immense. Hurricanes, because they stir up the surface, can cause 1000 Wm^-2 to be lost from the ocean, according to a paper by Curry I read recently.

Ian W
Reply to  lifeisthermal
September 30, 2020 12:17 am

There is a confusion of terms because temperature should not be the metric used for heat content. The correct metric for heat content of the atmosphere is kilojoules per kilogram. This is due to enthalpy of air which changes as humidity changes and latent heat content specifically in the lower atmosphere.

Terms like hotter/warming/cooler are colloquial terms and should not be used. The concern with climate change is heat content and heat being ‘trapped’. Temperature does not tell you how much heat is in volume of air. A volume of air at the surface at 75F and 100% humidity has twice the heat content in kilojoules per kilogram as a similar volume of air at the surface at 100F and 0% humidity.

It follows that small changes in humidity close to the surface can lead to large changes in ‘air temperature’. Comparative charts showing air temperatures/temperature anomalies/temperature averages to hundredths of a degree are displaying ignorance of enthalpy and are really just playing with numbers and as meaningless as an average phone number with a precision of two places of decimals.

Jean Parisot
Reply to  Ian W
September 30, 2020 1:11 am

Does a global wet bulb dataset exist?

Tim Gorman
Reply to  Ian W
September 30, 2020 4:41 am


Finally! Someone who understands!

The land temperature record is taken from stations at varying altitudes (i.e. pressure) and at varying humidity values. Trying to average these all together to come up with some kind of “heat” proxy is meaningless.

Clyde Spencer
Reply to  Tim Gorman
September 30, 2020 9:54 am

I’m going to play the Devil’s Advocate here. The ground stations are fixed at their respective elevations, so any temporal change is due to things other than elevation. Temperature is important because it is what is perceived by humans and impacts the growth of plants. People and plants don’t really care how many kilojoules/kilogram an air parcel contains. Although, the heat index, which accounts for relative humidity, might be a better indicator of the stress experienced by living organisms than just temperature. For modeling heat exchange in the Earth system, the energy in air parcels or volumes of water are essential. However, as a practical matter, it is the heat index that is of concern for its effects on living things. So, ultimately, heat content has to be converted into a measurable or perceivable temperature to put it into a biological context.

Tim Gorman
Reply to  Clyde Spencer
September 30, 2020 11:46 am


Trying to compare temperatures in Hays, Ks in the summer with a humidity of 80% with a summer temperature in Denver, CO with a humidity of 35% is meaningless. It isn’t a matter of time, it is a matter of heat content which is more than temperature. Temperature is a poor, poor proxy for heat content.

We don’t just experience temperature, we also experience humidity and pressure as well. As an intensive property h = H/m = (U+pV)/m. Humidity impacts the mass – m.

In fact, the heat index is calculated using humidity. But it does not take into account pressure.

The climate scientists try to use temperature as a proxy for heat content. As I said, it is a poor, poor proxy. It isn’t temperature that would cook the earth, it is heat content.

Robert W. Turner
Reply to  Ian W
September 30, 2020 6:05 am

That last sentence basically sums up modern climate “science”.

Robert W. Turner
Reply to  Ian W
September 30, 2020 6:42 am

And has anyone bothered to actually compare the atmosphere’s total precipitable water (TPW) and the net radiation balance (NRB) of Earth? It basically shows that backradiation hypothesis is junk science. The ocean off the east coast of each continent shows high TPW content relative to in the air relative to latitude, yet this shows no effect on the NRB.,17.47,436

Ed Bo
Reply to  Ian W
September 30, 2020 1:46 pm


While your claim that “moist enthalpy” of the air is the important metric, and not just temperature, you cannot compare in ratios as you do in your example (differences are fine).

This is because the zero point for moist enthalpy is arbitrary. Most commonly the value at 0 deg C and zero humidity is used, but that is just for convenience. Saying one state has “twice the heat content” as another is as incorrect as saying 100 deg F is twice as hot as 50 deg F.

Gordon A. Dressler
Reply to  lifeisthermal
September 30, 2020 12:19 am

lifeisthermal posted: “How the f**k did anyone get the idea that evaporation of water warms the planet?”

Evaporation of water from Earth’s surface (predominately from Earth’s oceans) must be at a near-equilibrium condition on a global average, else we would see atmospheric humidity continuously increasing or continuously decreasing. This is a basic tenet in the hydrological cycle for Earth . . . global evaporation is on balance with global precipitation. A key point here is that the latent heat of evaporation transferred to atmospheric water vapor is returned as the latent heat of condensation when water vapor returns as precipitation.

So, evaporation is the mechanism by which water vapor is maintained in the atmosphere. And water vapor is the predominate greenhouse gas in the atmosphere. And as such, water vapor is the primary ABSORBER of LWIR energy that would otherwise radiate directly to space and be lost from Earth’s surface. Because of this absorption of LWIR, the water vapor-containing atmosphere is capable of thermalizing and radiating energy isotropically (neglecting the effect of atmospheric clouds) across a wide spectrum . In turn, about half of this isotropic radiation goes back towards Earth’s surface, creating the warming commonly known as the greenhouse effect.

It is the continuous evaporation of water that, via the greenhouse effect, “warms the planet”.

That’s the idea.

Reply to  Gordon A. Dressler
September 30, 2020 1:19 am

A key point here is that the latent heat of evaporation transferred to atmospheric water vapor is returned as the latent heat of condensation when water vapor returns as precipitation.

True but incomplete. Latent heat of evaporation removes heat from the atmosphere at the surface. Latent heat of condensation returns the heat to the atmosphere at a higher altitude. In other words, the process moves heat away from the surface.

Tim Gorman
Reply to  Gordon A. Dressler
September 30, 2020 4:54 am


What happens to that radiation back toward the Earth? Does it warm the Earth? If so, doesn’t it then get re-radiated again by the Earth? Thus losing some of that reflected heat to space? Repeating over and over again.

What happens is like a damped sine wave. The Earth only heats if that damped sine wave never approaches zero. And that would mean that MINIMUM temperatures go up, not maximum temperatures. Of course that would drive the *average* temperature up but it is a good thing for humanity, not a bad thing.

Gordon A. Dressler
Reply to  Tim Gorman
September 30, 2020 7:53 am

If one examines Earth’s surface/atmosphere heat exchange processes at very fine spatial AND temporal resolution, then the Earth is never in a state of equilibrium.

Radiation exchange happens at the speed light, so your analogy to surface-atmosphere radiation exchange being like a damped sine wave (albeit being grossly incorrect) would result in approaching an asymptotic value within 3 milliseconds, conservatively (based on say, 30 cycles of damping over 15 km altitude at 3e5 km/sec travel speed).

On the other hand, if one examines Earth’s surface/atmosphere heat exchange processes at global-average and yearly-average resolution, then the Earth can be treated as being in near-equilibrium conditions over daily or monthly time periods, or even longer. This consideration is what allows scientists to talk about such things as the Kiehl & Trenberth diagram of Earth’s power fluxes (W/m^2) and balance, as well as ECS, the degree and trend of global warming, etc.

Tim Gorman
Reply to  Gordon A. Dressler
September 30, 2020 10:14 am


The issue isn’t the speed of light but how fast the process proceeds. The Earth doesn’t instantly cool to minimum temp when the sun goes dowm!

Average anything regarding the Earth system is meaningless. Averages hide the processes which are so important to understanding how the system actually works.

For intance, how do yearly or monthly averages tell you if minimums or maximums are changing, be they power fluxes or temperatures?

Alasdair Fairbairn
Reply to  Gordon A. Dressler
October 1, 2020 5:37 am

I’m afraid it is a duff idea.

You say: “Because of this absorption of LWIR, the water vapor-containing atmosphere is capable of thermalizing and radiating energy isotropically (neglecting the effect of atmospheric clouds) across a wide spectrum“.

This is incorrect as the absorbed LWIR by water is converted to Latent Heat at CONSTANT temperature; so there is NO increase in isotropic radiation from the water. What happens here is that this Latent Heat at some 694 Watthrs/Kg . gets driven up through the atmosphere and beyond for dissipation due to the inherent buoyancy of the vapor generated during evaporation.
In simple terms Water does NOT act like other greenhouse gases. It is a bit of a Joker in the Pack and causes much confusion if not properly understood.

Gordon A. Dressler
Reply to  Alasdair Fairbairn
October 1, 2020 10:58 am

Once water has evaporated from Earth’s surface it exists as gas at some partial pressure in the atmosphere. There is absolutely no question that water vapor, across the range of tropospheric pressures and temperatures, is capable of ABSORBING LWIR INDEPENDENT OF THE LATENT HEAT that was required for it to form from liquid water. And it only releases that latent heat when in condenses back into liquid water.

It appears you are very confused about the energy involved with phase change (“latent heat”) versus the energy involved with LWIR radiation exchanges and how LWIR-energized H2O molecules are able to exchange energy with other atmospheric gas molecules (primarily N2 and O2) with time constants in the range of 0.1 to 10 nanoseconds (the statistical thermodynamics process referred to as “thermalization”).

These processes also occur independent of whatever “buoyancy” (i.e., density differences of water vapor compared to all that of all other combined gases in the atmosphere) MAY exist at any given moment. On this topic, just ask yourself how it is possible that a heavy fog layer can ever develop over water if there is “inherent buoyancy of the vapor generated during evaporation” as you state. Also, you need to consider that facts surrounding temperature inversion layers developing in the atmosphere vis-à-vis buoyancy assertions.

When it comes down to the basic physics of radiation absorption, radiation emission, and statistical thermodynamics at the gas continuum level, H2O VAPOR obeys exactly the same physical laws as do all other gases, albeit with different values for the many parameters involved and with recognition that water vapor is a condensible greenhouse gas (unlike CO2, O3 and methane).

Now, you ended your post by making reference to confusion and proper understanding . . .

Gordon A. Dressler
Reply to  Gordon A. Dressler
October 1, 2020 11:50 am

Just to be clear, and to avoid undue criticism from other readers, I offer the following clarification to my post immediately above, second paragraph from the end, as regards obeying “exactly the same physical laws as all other gases”:

Radiation absorption in gases is highly dependent on the structure of the gas molecule being considered and its associated degrees-of-freedom in being able to first absorb a photon and then equipartitioning among the available degrees-of-freedom the energy of that absorbed photon. Note there is a certain chance, but very low statistical probability, that a given molecule can also emit a photon of the same exact energy of the one just absorbed.

To first order, for EM/photon energy to be absorbed the gas molecule under consideration needs to have either a permanent EM dipole moment (e.g, H2O, O3) or a molecular structure that can vibrate or bend in a way that causes the appearance of a temporary dipole moment (e.g., CO2, CH4). In comparison, N2 and O2 molecules have neither a permanent dipole moment nor bending, stretching or rotational degree-of-freedom that created temporary appearance of dipole moments, and hence they do not absorb photos across the visible-to-LWIR spectrum of radiation. Specifically, N2 and O2 are not greenhouse gases.

So, I should have more properly stated that all gases are SUBJECT TO the same physical laws governing radiation absorption and radiation emission, instead of stating that they OBEY the same physical laws.

Patrick MJD
Reply to  lifeisthermal
September 30, 2020 12:57 am

And how does it amplify?

Reply to  Patrick MJD
September 30, 2020 9:22 am

It’s like when you shout too loudly on a snow covered mountain. One tiny snow flake moves and that causes another one to start down hill and pretty soon you’re six feet deep in snow. Something like that.

Patrick MJD
Reply to  commieBob
September 30, 2020 5:38 pm

Bad analogy. Amplification requires some sort of additional energy.

Reply to  Patrick MJD
October 1, 2020 7:42 am

It was sort of tongue in cheek. That said, we do talk about avalanches with regard to transistors and lasers.

When James Hansen misapplied Bode’s feedback analysis, he displayed less understanding of electronics and feedback systems than the typical second year engineering student.

Reply to  lifeisthermal
September 30, 2020 2:22 am

“Why does the greenhouse theory consistently make claims that is the opposite to proven and widely applied physics?”
One possible answer is because of the definition of terms used.
Here is my attempt at definitions (h/t Humpty Dumpty).
1. Greenhouse Effect
This is a calculated value determined from an equation of radiative balance of the increase in average surface temperature for a terrestrial planet with a dense (> 10 Kpa i.e. >0.1 bar) atmosphere compared to an equivalent vacuum (no atmosphere) planet. Theory holds that the Greenhouse Effect is due to “Back Radiation” from Greenhouse (polyatomic) Gases.
2. Greenhouse Gas
Those gas molecules that are not monoatomic (n=1; Argon) or diatomic (n= 2; Nitrogen) but are polyatomic (n> 2; e.g. water vapour, methane and carbon dioxide). It is the polyatomic molecular gases (n>2) that produce the observed and measured impact on the thermal radiant opacity of a planetary atmosphere.
3. Greenhouse Gas warming
The surface warming effect that is ascribed to the presence of polyatomic molecules in the atmosphere that result in a reduced atmospheric thermal radiant opacity.

Reply to  Philip Mulholland
September 30, 2020 4:09 am

OK now using my terms defined above let’s see if I can nail this down.
The Greenhouse Effect is a theoretical concept, it comes from an equation loaded with assumptions e.g. Divide solar irradiance by 4; The planetary emissivity is that of a black body; We can use long term averages etc.
What we have here is the attribution of all of the computed Greenhouse Effect to a single cause namely Thermal Radiant Opacity, because it is by thermal radiation to space that a planet loses energy. This is a reasonable assumption but it is an assumption of externality. The greenhouse effect of surface warming however is an internal feature of planetary climate.
The key issue about the Greenhouse Effect is lag. Once a system has a delay then it must store energy to account for that lag. This is why in our climate model Stephen Wilde and I use the concept of an Atmospheric Reservoir as a store of energy. Even though the system may be in balance – Energy in equals Energy out the lag requirement of energy storage can only be satisfied by taking full account of the following mechanisms:
1. An atmospheric mass motion induced surface temperature rise.
2. A non-thermal energy store e.g.
a. Potential energy of air (meteorology).
b. Potential energy of water (hydrology).
c. Phase change energy of water (latent heat).
d. Biochemical energy (e.g. photosynthesis).
e. Translational energy (wind motion).
f. Geologic energy (e.g. mineral salt formation).
g. Oceanography.
h. Etcetera
The key problem with ascribing the planetary Greenhouse Effect to atmospheric thermal radiant opacity is that the lag mechanism of radiation is just too fast.

Robert W. Turner
Reply to  Philip Mulholland
September 30, 2020 6:13 am

They also do not consider conductive heat transfer from low radiating gases to the high radiating gases. If you increase emissivity but absorption is not the only way the substance is being thermalized, then you will have net cooling. Backradiation hypothesis must pretend that N2 and O2 are only warmed by the so-called greenhouse gases and never the other way around.

Reply to  Robert W. Turner
September 30, 2020 8:25 am

ghg below the altitude that emission time of photon is less than the time between collisions a hot ghg molecule is most likely to transfer its energy to another molecule rather than emitting a photon. Thus any atmospheric gas gets warmed by the ghg molecule. N2 and O2 are most abundant and so most frequently get warmed by the ghg. Neither of these emit significant photons to get rid of the energy. But of course will transfer the energy very quickly to another molecule ghg or not
The energy transfer between ghg and non ghgs is 2 way but only a ghg or substance (cloud/water/dust/earth) can radiate to space. a substance will radiate as a grey body a ghg will radiate at various wavelengths only

The radiation will occur in all directions but because the atmosphere is such a thin layer around the earth the averaged direction is up or down.
In either direction photons will get absorbed and energy transferred between ghg and non ghg. This will continue until the photons escape to space or get absorbed by the earth or hit a “substance” that radiates at different wavelengths to the ghgs.

Tim Gorman
Reply to  Robert W. Turner
September 30, 2020 11:51 am


“the averaged direction is up or down.”

That’s not actually true. When you get up into the troposphere and stratosphere the angle subsumed by the earth is less than 180deg. So using half as an average is starting off wrong.

Reply to  Robert W. Turner
September 30, 2020 2:25 pm

Tim Gorman September 30, 2020 at 11:51 am
When you get up into the troposphere and stratosphere the angle subsumed by the earth is less than 180deg. So using half as an average is starting off wrong.
well the emission level to space is around 10 to 15km at that height the horizon is only 3 to 4° down from horizontal so not a gross error!

Reply to  Robert W. Turner
September 30, 2020 3:06 pm

poor half-runt.

He has just admitted that the atmosphere is controlled by the density gradient, and hence is UNAFFECTED by the level of atmospheric CO2

Thanks half-runt. ! 🙂

Reply to  Robert W. Turner
September 30, 2020 3:10 pm

hot ghg molecule is most likely to transfer its energy to another molecule rather than emitting a photon.

Error .. the absorbed photon does not make the GHG “hot”

Correct…. transfer to another molecule means the energy is NOT TRAPPED. (another erroneous AGW meme)

It is now part of the atmosphere which is controlled by the molecular density gradient. (proven).

Therefore, CO2 causes no warming, which is why you are incapable of finding any evidence that it does.

Phil Salmon
Reply to  Robert W. Turner
September 30, 2020 11:02 pm

It’s strange that the key assertion of CAGW that non GH gasses (O2, N2, Ar) don’t interact with IR, is so rarely tested. It’s not difficult or expensive to simply test this hypothesis.

When it is tested, it is found to be false. Air, pure CO2 and argon all heat up in an IR field exactly the same:

Alasdair Fairbairn
Reply to  Phil Salmon
October 1, 2020 3:24 am

Dead true; but these gases only absorb little of the the radiation which passes through. CO2 and other greenhouse gases tend to absorb more so heat up more. Water is the Joker in the Pack as; whereas in absorbs more, the energy is converted into Latent Heat at CONSTANT temperature; so it doesn’t heat up.
Few people know this so it is generally assumed that water tends to warm the planet; but the opposite is true when you delve into the actual behaviour of water .

Reply to  Robert W. Turner
October 1, 2020 7:52 am

CO2 and other greenhouse gases tend to absorb more

Apparently not. According to this experimental paper, heat absorption by whole dry air, CO2 and argon in an IR field is the same. Surprising and hard to hear considering how much of a dogma it’s become that only ghgs interact with IR. This assumption is experimentally testable, and it turns out that it simply isn’t true. The fixation on absorption spectra makes people believe that photoelectric absorption si the only mechanism of energy transfer between light and gas. But this is not true – Einstein pointed out that energy exchange between light and gas is similar to that between gas molecules, following Maxwellian and Plank laws, and that absorption and emission energies play little role in this.

Gary Pearse
Reply to  Philip Mulholland
September 30, 2020 5:46 am

Philip, the dividing of solar irradiation by four is not an assumption. It is because the earth is a sphere and not a planar surface. On a planar surface one square meter is indistinguishable from every other one. On a sphere, the only square meters that receive the full 1367W/sq.m. are those along the equator with the sun directly overhead. All the others are inclined.

Now you could use calculus to sum all the irradiation from each sqm to get the average radiation/ sqm, but this is done for you by imagining the earth presenting a disc to the sun instead of a hemisphere, basically what we would see from a distance in space. Indeed, the geometry reflects this idea.

Area of the ‘disk’ =pi r^2
Area of a sphere =4(pi r^2), exactly 4 times that of the disk.

The hemisphere illuminated is of course 2pi r^2, which is twice that of the disk, but the average for the whole earth must include the illuminated half.

Gary Pearse
Reply to  Gary Pearse
September 30, 2020 7:56 am

&^%$# unilluminated, that is.

Reply to  Gary Pearse
September 30, 2020 8:03 am

“the dividing of solar irradiation by four is not an assumption.”
The sun does not shine onto the surface of the ground at night.
I sat in the lecture theatre of the Environmental Science department at Bailrigg in 1972, and it was explicitly explained to us that the purpose of the divide by 4 process was to establish the thermal radiating exhaust flux from the total area of the planet.
The idea that irradiance must be divided by 4, and therefore make the Sun too weak to heat the planet is total utter and absolute nonsense.

Reply to  Philip Mulholland
September 30, 2020 8:31 am

“unilluminated, that is.”

Here is a work in progress model that suggests how daytime divide by 2 irradiance of the sunlit Atmospheric Reservoir can be made to work.
See Figure 7

Gary Pearse
Reply to  Philip Mulholland
September 30, 2020 11:27 am

Philip, I’m afraid the lecturer was simply wrong. If you can find something wrong with my geometry. I.e. pi r^2 for the ‘disk’ area and 4(pi r^2) for area of a sphere the average irradiance for the whole sphere is clearly one fourth of that at the zenith on the equator. No doubt about that.

Now whether that means anything for its application to the problem may be in question. A square meter heated up with irradiance on the equator emitting at T^4 is much different than a tilted square meter at 45° Lat, receiving half that of the equatorial sqm and emitting at its T^4

Reply to  Philip Mulholland
September 30, 2020 2:30 pm

I know what I heard and why.
The process was described to us as a mathematical trick.
The explanation?
Because it is so difficult to calculate the output radiant flux for an illuminated rotating globe.

It is the application of your reduced intensity total global irradiance concept to the reality of an unlit hemisphere that is the problem.

Wim Röst
Reply to  Philip Mulholland
September 30, 2020 6:08 am

To add: Greenhouse gas radiative warming is just INITIAL warming. Our complex climate system has many ways to diminish (!) every initial warming. ‘Forgetting’ or ‘miscalculating’ surface cooling systems make models run hot. The real climate system performs better.

Reply to  lifeisthermal
September 30, 2020 9:27 am

You are right. Evaporation is indo-thermic. Also, condensation in clouds is exothermic. A better measure of energy transfer is dew-point temperature rather than air temperature. In the tropics, there is very little difference between the dew-point at the surface of the ocean and the dew-point at the bottom of thunder clouds. Thus, there is very little vertical energy transfer between them by radiation. The dew-point temperature at the top of thunder clouds is less than zero. There is a lot of vertical transfer of kinetic energy in thunder clouds. That energy is partially radiated to space. However, most is returned to the surface as rain or hail. A small amount is transported as high clouds to the poles where it is returned to the surface. Water cycles are controlling surface temperatures; not CO2. CO2 is just going along for the ride.

The Monster
Reply to  lifeisthermal
September 30, 2020 11:10 am

Also, the evaporation of water at the surface, combined with the formation of high-altitude clouds, and the freezing of water vapor near the tropopause in thunderstorms, means that the cycle of evaporation and precipitation blocks some insolation, and transports heat through those layers of “greenhouse-gas”-laden atmosphere. The models don’t consider these effects.

Michael Jankowski
Reply to  lifeisthermal
September 30, 2020 4:46 pm


We also pack some things with carbon dioxide (dry ice) to keep them cold. Does that mean CO2 is not a greenhouse gas?

September 29, 2020 11:22 pm

Anthony, I have been considering the effect of water vapour in the atmosphere and energy considerations. I am aware of the phase change energy requirements of water but something I am not sure how it is considered in the models is the energy required to move the water around in the atmosphere once it is in vapour form. From the conservation of energy it is very clear that there are huge amounts of potential energy in the water in clouds, notwithstanding phase change requirements. This is demonstrated by hydro electric plants that are essentially fed by rain water lifted to high elevations and that transform the energy through the turbines. There is obviously a huge amount of energy lost in dropping water/snow from the clouds to the mountain tops but significant amounts are retained. Again in considering the conservation of energy, there are huge amounts of energy required to move the water even in cloud form. I am curious as to how this vast sink and source of energy is treated in the global circulation models. There is a huge buffer of (potential) energy stored in clouds that back of the envelope calcs indicate is a significant factor of the incident solar energy. Is this energy adequately addressed in the GCM’s? I have heard of no discussion on this topic in the 10 to 15 years I have been following the climate change debate.

Reply to  TasChas
September 29, 2020 11:32 pm

You´re correct, there´s a lot of work needed for the atmospheric water circulation. And work equals cooling as it is driven by the heat flow from the surface. According to the first law, dU=Q-W, the work is subtracted from the internal energy leaving less heat. When work is done by a system it results in cooling. When water evaporates both the water surface and air cools. The water molecules carry this energy to colder regions and dump it when condensating, away from the heat source(surface), while at the same time blocking heat flow from the sun with clouds. Then when rain falls, the surface is cooled again.
So it´s cooling+cooling+cooling+cooling. Water vapor does not warm this planet.

Reply to  lifeisthermal
September 30, 2020 4:02 am

“So it´s cooling+cooling+cooling+cooling. Water vapor does not warm this planet.”
It doesn’t make this planet hot.
But ocean does have higher average temperature than land.
To get hot, you need dry conditions- deserts are hot. Tropical islands are nice- though tropical islands have higher average yearly temperature.
No only are deserts hot but they also cold.
We are in Ice Age with the cold average temperature of 15 C, because 1/2 the Planet has low average temperature. The 1/2 of planet with higher average temperature is a latitude lower than, say, 35 degrees North and South. So other 1/2 is higher than 35 degree, North and South. And small part this region is polar regions which is pretty friggin cold and get little Sunlight {that does any warming- equal amount of daylight globally, every year.
Europe would be quite unpleasantly cold if water vapor wasn’t warming it, such water vapor comes the warmth of Gulf Stream.
And this cold 1/2 of world, would much cold if not from the water vapor mostly originating from the tropical ocean heat engine.
And the 15 C average temperature is a bit misleading because warm 1/2 is significantly increasing the class average score to 15 C.
For instance average ocean surface temperature is 17 C, but warming than might seem because 40% of ocean is tropical ocean which 26 C and 60% of rest of ocean is about 11 C. Anyhow 15 C is cold and 11 C is colder. And Canada and Russian are a freezer. In summer they are warmer, but in winter they much colder than freezers. But both would be even colder if the ocean was adding some heat to them. So global warming means, largely means, warming these frozen wastelands. So less freezing cold winters. And both are quite dry, and making them wetter. The vast Tundra gets less moisture than most deserts. And so then maybe some trees can grow.
Not mention it’s possible that Sahara Desert might green- and increase it’s average temperature.
But our ocean is still about 3.5 and needs to warm to about 4 C before we have the illusion of not being in an Ice Age {we would be still in an Ice Age- but be in the warmer bits of our millions years of Ice Age}.

Jim Gorman
Reply to  lifeisthermal
September 30, 2020 10:19 am

lifeisthermal –> “the work is subtracted from the internal energy leaving less heat”

Correct, however, as you say, “The water molecules carry this energy to colder regions”. Carrying also is work and energy is expended working against gravity.

Mark A Luhman
Reply to  TasChas
September 29, 2020 11:32 pm

Your questions are far beyond anything so called climate scientist are willing to answer. They will remain unanswered for a very long time. After it would require a lot of work.

Joel O'Bryan
Reply to  TasChas
September 29, 2020 11:59 pm

All the effects of water and water vapor phase change effects happen where the physics are 1) unknown or 2) too complex to model, or 3) too small scale to model in 25 km grid scales. Thus water phase changes, convection cells (cumulonimbus rain showers), and the microphysics of water droplets as clouds are parameterized in the GCMs.

Once the water vapor physics are parameterized to “best guesses”, those effects are simply biased assumptions implicit in the output. They represent the bias of the modelers. In most cases the parameters are poorly constrained by observation, and thus the parameter sets are degenerate. (degenerate meaning multiple different, offsetting values of sets of parameter values can be used.)

Those parameters are tuned to get the output CO2 sensitivities the modelers expect.
The late Dr. Richard Feynman had a term for this kind of science, “Cargo Cult Science.”
A better term today for climate models would be “pseudoscience.”

Reply to  TasChas
September 30, 2020 2:43 am

Seems not immediately obvious but water vapor requires little to no work to move up as mostly gravity does the job in an adiabatic process. Dry air is denser than humid air and thus the falling denser air lifts up the humid air and little or no external energy is needed. The same manner that a see-saw will lift one side with just a nudge even if both ends carry 1 ton of mass each.
However, when water vapor condenses, it losses heat to the surrounding air an seemingly lose energy. But in return, it gains potential energy because it now becomes heavier that the surrounding air and falls. All this energy, then, comes initially from the heat of vaporization when the sun heats the ocean, plants and animals transpire, things burn.

September 29, 2020 11:35 pm

Any article, description, statement or even buzzword that says “greenhouse” immediately falsifies itself.

September 29, 2020 11:48 pm

CAGW fails HS physics because they constantly use temperature as a measurement of energy. It does not even have a straight line correlation. An example would be the claim energy trapped by CO2 can be measured by temperature alone. First thing that needs established, is it temperature or energy increase that is the concern. If energy, publish energy readings not temperature. Every time the wind changes(el-nino, el-nina) the temperature can change by a decades worth in a year.

Tim Gorman
Reply to  ironargonaut
September 30, 2020 5:05 am


Matthew Sykes
September 29, 2020 11:48 pm

Of course. NVAP-M, ISCCP, NOAA ESRL, all show no increase globally in water vapour. RSS, oceans only, does.

No WV increase means CO2 is safe and beneficial and we should try to get it to 1000 ppm.

Jean Parisot
Reply to  Matthew Sykes
September 30, 2020 1:16 am

I say 1200, but thats the argument we should be having – we high can we drive CO2.

Reply to  Jean Parisot
September 30, 2020 1:21 pm

We never going to get to 1000 or 1200 ppm of CO2.
Because Earth is full of life and we have a cold Ocean.
And because the highest potential in terms of “fossil fuel”
Is ocean Methane Hydrate.
“This research is important 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. If these deposits can be efficiently and economically developed, methane hydrate could become the next energy game changer.”
Now I was looking for some number of how much more energy than coal, but as wild guess say it’s 4 times as much energy as compared to all remaining coal on Earth. Maybe it same maybe more than 10 times, it doesn’t much matter.
What matters is getting point of actually mining 1/1000th of these ocean methane hydrate deposits.
I say 1/1000th knowing this a lot, but once one done that much, the initial higher cost of doing and how exactly it’s done will have been developed and it would be very cheap natural gas. And because it’s done in ocean and because such deposits are all around the world, one get a big increase in global natural gas use, and make any other fossil fuel use, as obsolete as whale oil for lamps.
So have natural gas and nuclear power as only energy used in terms of 99% of energy used globally.
So what remains is when could we {or can we} get to point of using as much 1/1000th of it. It could take more 50 years, and then thereafter one time it takes to eliminate all other “fossil fuel” use, which take another 20 years.
Now, it could instead, the focus become more about Nuclear power, and well China will have basically used up all it’s coal in 30 years, importing all coal china needs is not going to work economically. And then remaining coal is Russia, US, and some others. And Russia small economy and exporting any amount coal is unlikely. Coal is sort of like mining dirt, exporting it is like exporting expensive dirt- it’s hard to do on large scale, you spending a lot money moving it. Whereas with gas, it’s cheap to move and cheap to distribute to anyone who needs it.

Gordon A. Dressler
September 29, 2020 11:51 pm

From the above article: “Water vapor increases with global warming and in the climate models it amplifies the direct small warming caused by anthropogenic greenhouse gas emissions.”

Anthony, might we agree that the word “presumed” could safely be added before the words “direct small warming caused by”?

And I believe any warming amplification due to “water vapor” depends significantly on how that term is incorporated in any given climate model: does it mean TPW or just average relative humidity between Earth’s surface and cloud base wherever clouds form at any specific location on Earth. There is a big difference between the two.

The formation of visible clouds increases albedo for incoming solar radiation wherever and whenever they appear — a “cooling” effect on the atmosphere and Earth’s surface.

The formation of clouds increases atmospheric absorption of incoming solar radiation wherever and whenever they appear — a heating effect on the atmosphere, but a “cooling” effect at the Earth’s surface.

The percent of sky covered by obscuring clouds directly reduces the amount of surface LWIR, and even near-surface atmospheric LWIR, that can radiate directly to space through the “atmospheric window”— heating both the atmosphere and surface.

The formation of clouds releases the latent heat of H2O evaporation/condensation up in the atmosphere wherever and whenever they appear, which would otherwise not occur, causing a great change in the vertical distribution of energy within the atmosphere — net effect, who knows? Maybe Willis Eschenbach (and he can certainly comment on the effects of cumulonimbus clouds).

The energy gradients at surface that develop between sunlit areas and those shaded by clouds serve to increase surface winds, and hence convective transport of energy between surface and atmosphere — a heating effect on the atmosphere for areas with surface temperature higher than near-surface atmospheric temperature, but a direct cooling effect on the atmosphere for areas with surface temperatures lower than near-surface atmospheric temperature.

Bottom line: if one is concerned about water vapor (TPW) within Earth’s atmosphere, one sure better be concerned about how such affects cloud formation and cloud coverage extent.

For reference, on a global average basis Earth typically has :
— about 67% cloud coverage (ref:,clouds%20at%20any%20one%20time. )
— average relative humidity of 80% over the oceans (ref: )

Ian W
Reply to  Gordon A. Dressler
September 30, 2020 1:26 am

Again the problem with words such as the colloquial ‘heating effect’.

If there is a layer of stratus at dawn the sun comes up and some solar radiation is scattered /reflected out to space as albedo effect. However, some solar radiation is absorbed by the water droplets that then start changing state to water vapor when the molecules of water have absorbed sufficient latent heat of evaporation. Eventually, the clouds ‘burn off’ i.e. become totally water vapor and solar energy now reaches the surface. A considerable amount of solar energy has been converted to latent heat where the cloud had been but there has been no change in temperature the temperature profile is similar to that in a glass of water with an ice cube melting. This is another occasion when heat content changes (in kilojoules per kilogram) have no effect on atmospheric temperature. Thus the terms warming and cooling are not appropriate to indicate the significant change in heat content of clouds forming (releasing energy) or evaporating (absorbing energy) which can all happen with no ‘temperature’ change.

Gordon A. Dressler
Reply to  Ian W
September 30, 2020 7:04 am

Ian W, you posted: “Thus the terms warming and cooling are not appropriate to indicate the significant change in heat content of clouds forming (releasing energy) or evaporating (absorbing energy) which can all happen with no ‘temperature’ change.”

Please identify the specific source and sink of thermal energy (to supply/absorb latent heat) when a cloud evaporates or condenses, respectively, at night. Or do you not believe such things are possible?

Alasdair Fairbairn
Reply to  Gordon A. Dressler
September 30, 2020 7:28 am

The sources and sinks relate mainly to the Latent Heat and potential energy involved apart from other things such as wind velocity or electrical potentials.etc. Neither of these have a temperature value.
We only see about half of a cloud being just the water droplets. Within, however, is the vapor(gas) which tends to rise due to its buoyancy with the droplets tending to fall due to gravity. This creates shear stresses which, again contribute to the sources and sinks.

Gordon A. Dressler
Reply to  Alasdair Fairbairn
September 30, 2020 8:31 am

Shear stresses are forces applied over areas . . . they are not energy sources nor energy sinks.

And, specifically, you did not address the request that I made in my last paragraph in my previous posting.

Alasdair Fairbairn
Reply to  Gordon A. Dressler
October 1, 2020 6:40 am

1) Shear stresses are forces as you say and when they move energy is involved.
2) With your questions are you looking for a freeby science course? I suggest you do your own homework.

September 29, 2020 11:51 pm

Genuine question:

Does the decline in water vapour in the atmosphere allow more of the suns energy in?

I’m thinking cloud cover (Pinker et al).

Richard M
Reply to  Redge
September 30, 2020 6:10 am

Redge, more likely there is less solar energy getting in. The reason for less water vapor is it condensed out into clouds which reflect the solar energy.

Reply to  Redge
September 30, 2020 6:42 am

Too complex to answer there are pluses and minuses across the frequency range.

Take UVA it largely passes thru clouds but is usually reflected by snow, beaches however wet those surfaces and the reflection is hugely different. So to even answer your question in this band is difficult because we need to know is the increased water vapour leading to more rain?

Now if you go down to the IR range increased water vapour means increased absorption by water however clouds are excellent emitters of infrared radiation. So again the problem has both plus and minus how much vapour increase produces how much cloud increase?

You ask the problem in the worse case possible you are wanting to know the sum of changes in all frequency ranges and to do that you need much more detail about exactly what changes on what frequencies and the integrate the result. The simple answer is that level of detail is not known.

China is the only country that would have some limited data because to do this by measurement you need to be able to fire entangled photons from space and do what is called “absolute radiance measurement”. They will have scanned the IR window frequencies finding the best channel (aka frequency) to conduct their space based QM experiments they are doing. Basically what you then do is get data from the vertical column the beam is being fired each day, week, year and look at the changes.

Reply to  Redge
September 30, 2020 10:48 am

Thanks for the answers, guys

Michael Hammer
September 30, 2020 12:13 am

I keep hearing that as CO2 warms the world more water evaporates and since water vapour is also green house gas that further warms the world – positive feedback. The same group also state that the warming leads to a reduction in low cloud cover. To me this represents a paradox. If more water evaporates there must be more rain (or are people saying water continuously collects in the atmosphere?) but rain only comes from low dense clouds so how can more evaporation lead to less cloud cover? Low clouds are known to be net cooling so if more rain means more low clouds, that would represent negative feedback? If anyone can shed some light on this paradox I would love to hear it.

Reply to  Michael Hammer
September 30, 2020 1:27 am

> To me this represents a paradox.
> If more water evaporates there must be more rain
>(or are people saying water continuously collects in the atmosphere?)
Actually, water CAN continuously collect in the atmosphere. Warmer air can contain more water (heating air decreases its relative humidity with the same absolute water content). So without considering other factors, more water is expected in the air with increasing temperatures. Now this is the “rough” effect of temperature. The actual changes are much harder to predict, that’s why climate scientists use quite complicated models. These models pretty accurately predict climate parameters, so we have no reason to doubt if they predict low cloud cover.

Reply to  nyolci
September 30, 2020 4:24 am

“These models pretty accurately predict climate parameters”

Except when they DON’T !

“if they predict low cloud cover”

The “climate” models have basically ZERO skill when it comes to cloud and rainfall.

It all just a biased WAG !

Reply to  nyolci
September 30, 2020 7:46 am

pretty accurately predict climate parameters?

Is that like saying that socialists are always predicting that socialism will work?

Michael Hammer
September 30, 2020 12:26 am

Another paradox;
The theory of anthropogenic global warming states;
1 CO2 is a greenhouse gas
2 greenhouse gases act like a blanket, reducing Earth’s energy loss to space.
3 Man’s use of fossil fuels is increasing atmospheric CO2 and this will reduce Earths energy loss to space causing Earth to warm.
4 As Earth warms, more water evaporates and since water vapour is also a green house gas this will further reduce Earth’s energy loss to space thereby increasing the amount of warming to dangerous levels. (positive feedback).
5 The direct impact of the rise in CO2 from 345 ppm in 1985 to 415ppm today should reduce OLR by about 0.9 watts/sqM (before water vapour feedbacks)

Earth’s energy loss is through outgoing longwave radiation or OLR for short and this has been measured since almost the start of the satellite era. If, according to the AGW theory, rising CO2 should reduce OLR and that reduction should be amplified by water vapour feedback, we can easily check the prediction by looking at whether OLR is in fact decreasing as CO2 levels rise.

In fact the satellite data shows OLR has been rising not falling over the satellite era and the rate of rise is exactly what one would expect for the claimed amount of warming (2 watts/sqM corresponding to about 0.7C warming). There is no apparent impact of rising CO2 (or water vapour) on OLR, it simply tracks the surface temperature. If the theory claims rising CO2 depresses OLR and OLR has been rising surely that destroys the theory of AGW?

I know about the comments that in fact Earth is warming because absorbed shortwave (solar) radiation (ASR)is increasing (not OLR reducing) but how does rising CO2 influence ASR. For ASR to rise, given the solar constant is indeed constant, albedo must be reducing and that can only be due to a reduction in surface albedo (satellite data shows this has not changed) or a reduction in cloud cover. Satellite data shows this in indeed the case but how does rising CO2 act to reduce cloud cover? As I pointed out already, more water evaporating must mean more rain and that must mean more low cloud not less.

Einstein famously stated “no amount of experimentation can ever prove me right but a single experiment can prove me wrong” Is this not just such an “experiment”?

Reply to  Michael Hammer
September 30, 2020 1:18 am

> Is this not just such an “experiment”?
No. The increase in outgoing long range is totally expected and in line with predictions. The “trapped” radiation has increased too. The net effect is warming.

Reply to  nyolci
September 30, 2020 4:11 am

Let us be clear.
You are saying that Michael Hammer is correct in stating that the satellite data shows OLR has been rising not falling over the satellite era.
At NOAA there is the “ NOAA’s Outgoing Longwave Radiation- Daily Climate Data Record (OLR- Daily CDR ) :NOAA/ PSL Interpolated Version.”
There is similar monthly data at NOAA.
Whilst there is an enormous amount of data there, can you point to any conclusion the OLR is increasing rather than falling or vice versa from 1979?
You then add that the trapped radiation is increasing too with a net effect of warming.
Can we nail down the first issue as to whether OLR to outer space is increasing, decreasing or unchanged over the satellite era?

Reply to  Herbert
September 30, 2020 7:26 am

Oops, sorry, I mixed up something. OLR should be quite stable, and it is, around 240 W/m^2. The total absorption of heat is around 0.6 W/m^2, around 0.25% of OLR.

Michael Hammer
Reply to  Herbert
September 30, 2020 1:33 pm

Herbert, just to be clear have a look at

Decadal Changes of Earth’s Outgoing Longwave radiation
Steven Dewitte * andNicolas Clerbaux remote sensing 2018

and have a look at the yellow plot generated by NASA assuming OLR is ONLY influenced by temperature Look at just how closely it tracks actual OLR. No long time constant or delays there.

Nyolci says the increase in outgoing long wave radiation is totally expected. Really, on what basis? His bland statement does not make it so. SOME REASONS PLEASE! The theory of CAGW is quite specific, the warming is caused by rising CO2 reducing Earth’s energy loss to space. They state that doubling CO2 should reduce OLR by 3 watts/sqM before feedbacks! Well OLR is not falling, it should have fallen by 0.9 watts/sqM just for the direct impact of the rise in CO2 (before feedbacks) but instead it has risen by 2.1 watts/sqM.

It is rising because Earth is warming and the amount of rise is exactly what we would expect from the claimed temperature rise assuming NO suppression from rising CO2 or rising water vapour. If rising CO2 and supposedly water vapour have no impact on OLR then how can they be causing warming?

Reply to  Michael Hammer
September 30, 2020 7:37 pm

Thanks for that paper. I have been trying to nail down this issue for some considerable time.
On a recent thread here, one of two papers advanced by the CSIRO to Sceptical Australian Senator Malcom Roberts was Harries (2001), in answer to his question, what papers do you rely on as evidence of CAGW?
The other was Marcott et al (2012).
Dr. Myles Allen relied on Harries in his “tutorial” to Judge Alsup in the Cal.v. BP et al litigation.
For a rebuttal of Harries (2001) see “ The AGW smoking gun”, February 17, 2010 at
The claim in that article is that there is no difference in OLR between 1970 and 2006.

Reply to  nyolci
September 30, 2020 4:32 am

Wow, talk about confused .. poor nyholist !

There is no radiation being “trapped”… I tiny thin weak sliver in the CO2 range, and a much wide spread in the H2O range is absorbed then either re-emitted or transferred by collisional energy to the remainder of the atmosphere.

OLR pretty much matches global atmospheric temperatures.

comment image

comment image

There is no divergence, there is no sign of any extra energy being trapped by increased atmospheric CO2.

Robert W. Turner
Reply to  fred250
September 30, 2020 6:34 am

Yep – In order to make their back radiation hypothesis (if you can even call it that) work, all of thermodynamics must be turned on its head. If something warms up, it is going to emit MORE radiation, not less, and any imbalance in ISR and OLR must be energy being stored in some other form than heat. The concept of trapping OLR, thus heating up, and therefore emitting less radiation is mind bogglingly stupid. It’s enough to make me feel like I’m living in the Twilight Zone and some people really are NPCs.

Alasdair Fairbairn
Reply to  Robert W. Turner
September 30, 2020 7:09 am

Yes. At the evaporation of water there is NO heating up or increase in radiation. The process occurs at constant temperature which makes the Planck sensitivity coefficient equal to Zero.
Any absorbed energy is converted to Latent Heat carried by the vapor(gas) generated.
The buoyancy of this vapor then carries the energy (some 694 Watthrs/Kg) up through the clouds etc. for dissipation irrespective of CO2 levels.

Jim Gorman
Reply to  Robert W. Turner
September 30, 2020 11:22 am

I recently began some research into “CO2 feedback”. Something I found interesting was that the sun’s radiation is about 50% in the infrared. H2O has four major absorption bands in the near IR which are very high energy vs the lower bands for CO2 in the far infrared.
Someone above mentioned clouds in the morning “burning off” which intrigued me. There are two kinds of water in clouds, vapor and liquid. I am not knowledgeable enough yet to know if vapor can absorb more IR but I am sure liquid (condensed vapor) can. This is what causes the burn off, liquid water absorbing the sun’s near IR and moving to vapor.

Finally if water is absorbing a goodly portion of the sun’s IR, even more water in the atmosphere will absorb even more. At the very least, half of this energy will be re-radiated back to the sky and never reach the earth. It is my guess that this process would more than offset any “positive feedback” from CO2.

Alasdair Fairbairn
Reply to  Jim Gorman
September 30, 2020 2:32 pm

Going back I recall mentioning the sun burning off the mists over a river.
You are close to explaining it but one needs to move away from expecting radiation to explain every thing.

What happens is that the radiation is absorbed by the water droplets in the mist and converted to Latent Heat carried by the generated vapor(gas). This is done without any increase in temperature. The vapor is lighter than dry air so rises up through the atmosphere and beyond for dissipation. Eventually all the water droplets get evaporated so the mist apparently disappears, which is not to say that the cloud has gone for it is still there but just comprising vapor which we cannot see.
The major energy movement here lies in this rising of the vapor up through the atmosphere carrying with it the Latent Heat. This done irrespective of CO2 levels and with an energy value far far greater than in the radiation process.
A kilogram of water evaporated contains some 694 Watthrs of energy.
Not many people realise that when they look at a cloud they only see about half of it ; for within it is the vapor, which is invisible and by rising, holds the water droplets in balance against gravity. To me- fascinating.

Reply to  fred250
September 30, 2020 8:11 am

> There is no radiation being “trapped”
> either re-emitted
around 35% of that is reflected back to earth,

> or transferred by collisional energy to the remainder of the atmosphere.
In other words, it heats the atmosphere itself.

All in all, a significant portion of radiation’s energy is trapped in Earth. Around 0.6 W/m^2 on average.

Reply to  nyolci
September 30, 2020 3:16 pm

“All in all, a significant portion of radiation’s energy is trapped in Earth. Around 0.6 W/m^2 on average.


That’s from the Trenberth flat-Earth chart which had error margins of ±10 (or more) W/m² on all its other fluxes, isn’t it.

ie.. its meaningless NONSENSE.

Just the sort of thing that you would gullibly accept.

Reply to  nyolci
September 30, 2020 3:23 pm

And how much natural energy do you think is consumed on Earth by movement, erosion etc etc ?

And do you REALLY think radiation is the only form of energy transfer..

OLR pretty much matches global atmospheric temperatures.

comment image

comment image

There is no divergence, there is no sign of any extra energy being trapped by increased atmospheric CO2.

DATA , not flat Earth charts with made up numbers with huge error margins.

Tim Gorman
Reply to  nyolci
September 30, 2020 5:13 am

Just how does radiation get “trapped”?

If back radiation warms the Earth won’t it just re-radiate that warmth? A certain amount of that re-radiation then gets lost to space with a certain amount of the re-radiated radiation being sent back to Earth. Then a certain amount of that re-radiated radiation will get re-radiated again. And over and over just like a damped sine wave.

So “what” is getting “trapped”?

Reply to  Tim Gorman
September 30, 2020 8:07 am

> Just how does radiation get “trapped”?
It’s reflected back.
I was not correct with the increase in OLR, I mixed up something. OLR should be quite stable, and it is. Actually it depends on short wave reflectivity too, so eg. decreasing ice cover may affect it in a non-intuitive way.

Michael Hammer
Reply to  nyolci
September 30, 2020 1:54 pm

Nyolci; OLR is NOT quite stable, it has risen 2.1 watts/sqM since 1985. Decreasing ice cover is not affecting the situation. If it were that would be reflected by a fall in surface albedo but if you care to look at the plots of surface albedo at;

you will see it is not changing. What is changing is cloudiness which is also shown at the above site. It has fallen by about 3% from 69% to 66% and that change reduces Earths albedo resulting in a increase of 2 watts/sqM in absorbed solar radiation. That will cause Earth to warm by about 0.66C which is exactly what has happened and OLR has risen by the same 2 watts/sqM which shows that the Earth is again is stable equilibrium – no locked in future warming.

So the question is, what has caused cloud cover to fall? There are also indications that it was rising before 1985 which could be what caused the cooling in the 1970’s. No doubt CAGW advocates will now claim that rising CO2 causes falling cloud cover – oops they are already claiming that. But such a claim raises new paradoxes. Starting with the fact that the fall in cloud cover does not show correlation with the rise in CO2.

Michael Hammer
Reply to  nyolci
September 30, 2020 2:43 pm

Most environmental scares follow the same formula. Take some known provable science which has an effect you can capitalise on, then extrapolate the impact until it becomes significant. If challenged raise ever more convoluted justifications of feedbacks and corollary impacts and add more and more complexity to obfuscate. Then claim that non experts cannot possibly have enough knowledge to comment meaningfully so the experts word should be taken as gospel. If there are still challenges apply the precautionary principle.

One cannot possibly address this situation by trying to answer the environmentalists claims. They are never ending, and in the end, so convoluted that no-one can understand them. The solution is to apply the scientific principle in the most basic straightforward way. A theory makes testable predictions – in this case that rising CO2 will lower OLR and that water vapour feedback will further lower OLR. Test that prediction experimentally – in this case, is OLR falling? No it is not. The core prediction of the theory is contradicted by experimental evidence therefore the theory is wrong.

The environmentalists respond by changing the predictions but not the overall thrust (at that point it becomes a dead giveaway that it is a case of any justification to support the desired ends ie: utterly suspect). In this case the change is; Ahh yes rising CO2 lowers OLR but the feedback from water vapour raises OLR again but in the process also raises absorbed solar radiation (ASR). So mysteriously the feedback raises OLR just enough to EXACTLY cancel out the fall due to CO2? Really!!! Further the experimental data shows the rise in temperature is due to reduction in cloudiness but how does increasing evaporation lead to less cloud and thus less rain. Over decades the oceans would end up in the sky. Evaporation and rain must balance long term. If in fact there is no increase in water evaporation then what is the source of the feedback? How does rising CO2 reduce cloudiness? Keep it simple, and test their core thesis experimentally. Do not follow them into the complexity swamp.

Reply to  nyolci
September 30, 2020 3:41 pm

I have to tell you answering you is beyond the time I have for this. At this point we should consult actual climate scientists. ‘Cos I don’t think (I wouldn’t bet with my money 🙂 ) that you have just discovered an actual cause of warming other than what climate scientists claim.

Reply to  nyolci
September 30, 2020 6:13 pm

“It’s reflected back.”

WRONG !! and total nonsense.

Seems that you don’t even know the mechanism the alarmists fantasies about…..

Clyde Spencer
Reply to  Tim Gorman
September 30, 2020 10:11 am

I think that we are looking at an infinite series of reflections, with some loss at each reflection. The question is whether the infinite series converges to some fixed value.

Tim Gorman
Reply to  Clyde Spencer
September 30, 2020 12:06 pm


” think that we are looking at an infinite series of reflections, with some loss at each reflection. The question is whether the infinite series converges to some fixed value.”

I agree pretty much. The convergence of the series is modified by external factors such as clouds so it can change. That is why it is so important to know what is happening with the whole temperature profile, not just the so-called “average value”.

Michael Hammer
Reply to  Tim Gorman
September 30, 2020 1:45 pm

The answer Tim is quite simple. GHG’s absorb electromagnetic energy at some wavelengths within the thermal infrared portion of the spectrum (between about 8 microns and 50 microns). The surface emissions at those wavelengths are absorbed by the GHG’s and converted to heat. But those GHG’s also radiate at the same wavelengths at which they absorb, so, throughout the atmosphere, radiation at the GHG wavelengths is continuously being absorbed and radiated. The actual intensity of radiation at those wavelengths at any altitude is simply a reflection of the atmospheric temperature at that altitude. However at the top of the GHG column there is no GHG above to absorb the upwards radiating energy and that energy can escape to space.

The overall effect is that at the GHG wavelengths, surface radiation is absorbed and replaced by radiation from the top of the GHG column (typically the tropopause or lower stratosphere). Since this region of the atmosphere is substantially colder than the surface the radiation intensity at the GHG wavelengths is less than the surface emission so overall the radiation loss to space is reduced.

This much of the theory of CAGW is right but the incremental situation is entirely another matter. The indications are that there is extremely strong negative feedback within the climate system (logarithmic warming from water vapour plus linear cooling from clouds) which renders the impact of rising CO2 on OLR indetectable.

Tim Gorman
Reply to  Michael Hammer
September 30, 2020 3:51 pm


” radiation at the GHG wavelengths is continuously being absorbed and radiated.”

But not just by GHG’s. Some of that radiated IR does go back toward Earth. What does earth do with it?

It’s why the Earth cools at night. It’s radiating away heat that it absorbed during the day. It’s radiating away heat being received from the GHG’s.

It’s why we don’t just see a step function for surface temperature when the sun goes down. Nighttime temps under the same conditions from sunset to sunrise don’t follow a logarithmic curve or a linear curve. The temp drops off more steeply early in the night and then tapers off. Just like a damped sine wave with exponential damping. That tells me that the GHG’s are not “trapping” heat, at least at the surface. And at least not like the CAGW advocates mean. The GHGs may be slowing down the loss of heat at night but that will only impact minimum temperatures by affecting the damping decay constant, not maximum temperatures.

Michael Hammer
Reply to  Michael Hammer
September 30, 2020 8:08 pm

Tim; I think you are creating complexity where none exists. Gases in the atmosphere that are not GHG’s do not absorb or radiate, if they did they would be GHG’s by definition. The Earth’s surface does of course absorb and radiate. Sure the atmosphere radiates down to the surface. By the way its only radiation from a thin layer close to the surface that radiates onto the surface. Radiation from higher up is reabsorbed by the atmosphere below. The surface absorbs such radiation and is warmed by it. The surface radiates as well of course and some of that radiation escapes to space (at wavelengths other than the GHG wavelengths). In the process the surface cools because it is radiating away energy.

Tim Gorman
Reply to  Michael Hammer
October 1, 2020 5:18 am


If the non-GHGs do warm from collisions with GHGs that have absorbed radiation then how do they lose the heat? If they can’t lose it then the earth would be a flaming ball by now.

I am not trying to address the totality of the thermodynamics of the system known as Earth. I am only addressing the claim of the CAGW advocates that “back radiation” from the GHGs is somehow “trapped” and represents the warming of the earth caused by CO2.

If the sun were to disappear tomorrow it would soon become obvious that there is no such thing as “trapped” heat. That damped sine wave of radiation would, sooner or later, see the earth approach somewhere just north of absolute zero.

Antero Ollila
September 30, 2020 12:50 am

I have one figure showing also empirical observations about the temperature and absolute humidity trends from 1979 (UAH temperature starting year) to 2017. It is the slide number 26 in this slideshow:

One can see in this figure that temperature increased from 1982 to 2002 but the absolute humidity decreased. This is against the assumption of positive water feedback theory of the IPCC.

Another observation is that during ENSO events this positive water feedback is working. That is the reason why El Ninos have global temperature effects because the humidity increase explains about 50 % of the temperature effect.

Something exceptional has happened since 2015 and it is that shortwave radiation (not the same as Total Solar Insolation) has increased strongly causing the temperature increase of about 0.3 C which the same increase explaining the pause ending:

Just one more comment. Why vary about the equilibrium climate sensitivity (ECS) when even the IPCC writes in the AR5 that the TCS/TCR is a better key figure during this century?

Wim Röst
Reply to  Antero Ollila
September 30, 2020 3:14 am
Antero Ollila
Reply to  Wim Röst
September 30, 2020 5:18 am

Thank you Wim. I just learned something. In this electronic environment we should learn at least one new thing every day just to keep our head above the surface.

Reply to  Antero Ollila
September 30, 2020 5:11 pm

Antero I looked at your informative slideshow <a href=<Fig.10, and see the IPCC claims Mankind=97.8% of forcing. You’ve claimed a lower value of CO2 forcing, so I was wondering what percentage you subscribe to mankind?

CO2 starts outgassing just before water vapor evaporates wrt tropical temperature, but monthly detrended CO2 shows CO2 lags tropical temperature by 1-2 months, and the 12mo change in CO2 lags HadSST3 by 10 months, so any potential CO2 forcing is out of sync with water vapor forcing by following it. How can CO2 really force the temperature if it follows the temperature?

comment image

comment image

The increase in shortwave radiation you found can be attributed to fewer clouds due to less tropical evaporation that resulted from low TSI during during those periods. I expressly talked about that and made predictions that have come true for SW US drought and hot summers in my LASP and AGU posters based on low TSI-driven solar minimum clearer skies.

CO2 sensitivity should be expressed as a function of sea surface temperature:

comment image

If you think CO2 is forcing things can you explain why it consistently lags temperature changes and water vapor? Has anyone who promotes CO2 forcing addressed these lags meaningfully?

Antero Ollila
Reply to  Bob Weber
September 30, 2020 8:35 pm

Dear Bob, You have particularly good remarks. Firstly, I have used in my carbon cycle model the delay of one year between the ocean temperature and the CO2 concentration change. There is exceptionally good correlation 0.83 between the tropical ocean temperature (=outgassing temperature) and CO2 concentration:

CO2 has its climate forcing effect regardless of this delay. In the long run yearly fluctuations are not important but the persistent and growing concentration of CO2 has the major role. The figure in the link above illustrates this very well. The simulations of my carbon cycle model shows that the ocean temperature changes cannot explain the growing CO2 concentration even though I have applied Henry’s law in my model.

Secondly, it is true that during the period 2015-2020 the trends of SW radiation has been increasing and the TSI radiation has been decreasing. But we should remember that the TSI has not the final impact on the ocean surface, but it is the SW radiation, because SW radiation = TSI minus reflected SW radiation (albedo effect).

Michael Hammer
Reply to  Antero Ollila
September 30, 2020 5:15 pm

Slightly off topic but I think of interest. Apologies, this is going to be a VERY long comment. I hope it is acceptable

I repeatedly hear comments from warmists that if there were no greenhouse gases in the atmosphere the earth would be 33C colder than it is at present. That comment makes me very angry because it is utter bunk. Any half way competent scientist MUST know this so therefore saying it is a clear act of deceit . Consider;
Earth’s atmosphere generates mechanical energy. It raises water to high altitudes powering hydroelectric generators, while wind can blow down trees and buildings, raise waves and drive wind turbines. So, where does this energy come from? Clearly from absorbed solar energy. That means earth’s surface and atmosphere is converting thermal energy into mechanical energy, the definition of a classic heat engine. Heat engines are governed by very well understood natural laws. A working fluid (in this case the atmosphere) cycles between a hot junction (where heat enters the system and is injected into the working fluid) and a separate cold junction (where heat is extracted from the working fluid and leaves the system). The maximum efficiency possible is the carnot efficiency ((Thot-Tcold)/Thot). Typically the hot junction is the hottest point in the system and the cold junction is the coldest point in the system.
In the case of earth, the hot junction is clearly earths’s surface and especially the surface in the tropics but where is the cold junction? There are 2 candidates, the first is the tropopause and the second is the poles. However the working fluid has to cycle between the hot and cold junction and because the earth is a rotating sphere the atmosphere rising at the equator cannot get to the poles. Firstly air rising at the equator is moving at the speed of earth’s surface 1600 km/hour but as it tries to move towards the poles the radius of rotation of the surface and thus the surface velocity is reducing. The equatorial air, moving faster, is thrown outwards in the plane of rotation. That can be resolved into an outward force normal to Earth’s surface and a force tangential to the surface pushing the air back towards the equator. It is why we do not have an equator to pole circulation but instead 3 coupled circulations – the Hadley cell, the Ferrel cell and the Polar cell. The second reason is that even if the equatorial air could get to the pole it would have to descend to transfer heat energy to the surface but if the pole is the cold junction by definition the pole would be colder than the descending air so there would be a temperature inversion inhibiting the air from falling. The cold junction of our climate heat engine is the tropopause not the poles.
Given the cold junction is the tropopause, heat energy must be leaving earth (to space) at this point and that is only possible by radiation. However, by definition a gas capable of radiating thermal infrared radiation is a green house gas. If there are no green house gases the tropopause cannot radiate energy so a necessary requirement for a heat engine is not met. In practical terms, the rising air cannot cool so it cannot lose energy which it needs to do in order to descend again. Thus convection stops and with time the entire atmosphere becomes vertically isothermal. Water vapour cannot condense because it needs to lose energy to do so (lose energy to where?) thus no clouds would form. If there is no condensation there can also be no evaporation otherwise the oceans would end up in the sky, the entire atmosphere would become saturated with respect to water vapour. Without convection no dust would be raised and what was in the atmosphere would eventually settle out so the sky would probably not be blue but closer to black. There would be no clouds, no wind, no rain, no significant waves on water, a completely static vertically isothermal atmosphere. The temperature would vary with latitude according to the solar energy absorbed by the surface at that latitude. Given a near transparent atmosphere Earth’s albedo would be close to the surface reflectivity. That is 70% water with a reflectivity of about 0.04.
In near Earth space the solar energy intensity is 1370 watts/sqM. For the Earth as a whole the average solar energy at the surface is 1370/4 * (1- albedo) but at the equator it is 1370/pi *(1-albedo) which, in the absence of convection will be close to 430 watts/sqM- maybe around 400 watts/sqM. Applying the Stefan Boltzmann law gives a surface temperature of 290K or 17C. Worse however, during the day the peak energy reaches close to 1300 watts/sqM (at noon). The surface temperature will depend on the thermal time constant but if you think about how hot beach sand, exposed concrete, metal surfaces can get on a warm summers day that time constant can be quite short- well under 1 hour. Again from Stefan Boltzmann law the temperature of those surfaces could then get to 389K or 116C. The air over those surface would be heated and rise. Of course at night the surface cools considerably but that creates a temperature inversion precluding convection and in the absence of green house gases the hot atmosphere could only cool by conduction back to the surface. Conductive heat transfer in air is extremely slow, much slower than convection. The atmosphere would end up at an equilibrium temperature much closer to the noon surface temperature than the average temperature! At such temperatures and without any rainfall land life would be very unlikely to exist or endure. Ocean life could possibly still be OK.
Due to the day/night surface temperature variation there could still be some conductive heat transfer allowing dew to form at night and some corresponding evaporation during the day but the effect would be tiny and limited to only the air very close to the surface. Dew but no rain.
Of course, away from the equator the temperature would not be quite as extreme but even where I am at latitude 37 south, the temperature inside a closed car in summer, which heats up because convection is prevented, can and alas too often does kill children in minutes (60C+)!!! This is not conjecture or modelling it is sadly proven fact. Without convection, the entire environment at that latitude would be in the same position as a closed car.
Without greenhouse gases the earth would not be 33C colder. Much of the atmosphere and land mass would be far hotter at least in summer (60% of Earth’s surface area lies between latitude 37N and 37S) although much colder at night. Temperatures which really would destroy life on Earth.
Very often, looking at an issue from a different perspective can give new illuminating insights. Looking at the atmosphere from the perspective of heat engine seems to be such a case.

Antero Ollila
Reply to  Michael Hammer
September 30, 2020 8:48 pm

To Michael Hammer. You are right at least in one thing. The GH effect is not caused by GH gases only. The Earth receives net energy from the Sun 240 W/m2 but the total energy absorbed by the surface is 510 W/m2. It means that the GH effect driving force is 510-240 = 270 W/m2. The IPCC and the climate establishment says that it is only 155 W/m2 caused by GH gases and clouds. The difference is 270-155 = 115 W/m2. From which source could this missing energy come from? The answer is very, very simple. It is the latent heat 91 and sensible heat 24 = 115 W/m2. This means that the contribution of CO2 is the GH effect is only 7 %.

September 30, 2020 12:55 am

That “decline” since 2010 is barely noticeable in that graph

Patrick MJD
September 30, 2020 12:57 am

Has anyone heard of evaporative coolers?

Reply to  Patrick MJD
September 30, 2020 1:03 am

Shhh! The science is settled! How dare you!

Reply to  Patrick MJD
September 30, 2020 7:24 am

Has anyone heard of vacuum bottles.

John Gorman
September 30, 2020 1:36 am

Could someone please plot the data as absolute humidity or at least dew point. RH can fall if the water content is stable and the temperature of the air mass increases. RH is not a useful measure of humidity. It effectively measures how much more water vapor you can stuff into that air parcel – not how much water is there.

Reply to  John Gorman
September 30, 2020 9:13 am

Average TPW is 25 millimeters and constant over decades.

Global Relative Humidity and Total Precipitable Water are two different things.

Alan Tomalty
September 30, 2020 2:06 am

I found a 1.8 C sensitivity to doubling CO2 based on the Modtran graph of upwelling IR . Of course the Modtran graph is different for every spot on the earth, but it could be averaged out. If you assume that the standard graph which everybody circulates is indeed that average , then in that graph you will see that at 15 micron wavelength, CO2 has already trapped at least 50% of the upward IR from the surface compared to the spectroscopy of the blackbody curve of 278 K. The sensitivity may well be less if someone would fit a curve equation to the upward IR and then integrate over the full spectrum . In that case the sensitivity may drop to as low as 1C.

Antero Ollila
Reply to  Alan Tomalty
September 30, 2020 8:51 pm

MODTRAN works well enough but you have to use the average global atmosphere profiles for water, temperature and pressure. Ther is no such kind of profiles available in MODTRAN. US Standard atmosphere is not such a thing.

September 30, 2020 2:35 am

I’m just shivering under fully overcast sky and 12C. Just few days ago, it was 28C during clear days. How can somebody say that water vapor content in atmosphere is increasing temperature.
Water vapor as gas can change energy on surface in range of 3W/m2. But water as droplets – fog/clouds is changing incoming energy on surface in range of 950W/m2.
Thermal impact of water vapor as gas is simply always offset by its impact as fog/clouds.
What I see form graphs in this article is that global warming is caused by decreased content of water in atmosphere from 1970. It is simply more sunny and warm.

Patrick MJD
Reply to  Peter
September 30, 2020 3:07 am

Where would be a good addition.

Reply to  Peter
September 30, 2020 9:31 am

“Thermal impact….is offset by its impact as fog/clouds”
You’ve hit it on the head. Without clouds, the Albedo of the planet would be less than 0.1 because the 70% water cover is around .05. Clouds, with an albedo of up to 0.9, and covering normally 60% of the planet ARE/IS the albedo of the planet with some minor adjustments for land and ice. And that albedo is controlled by the ocean surface temperature and its 7% more equilibrium water vapor content per degree of warming….making more clouds….reflecting more sunlight back into space….reducing heat input to the surface…..and on and on….Clouds control the Earth’s average temperature over a few days period, CO2 is a bit player.

Alasdair Fairbairn
September 30, 2020 2:50 am

The claim that water provides a POSITIVE feedback to the GHE is only true if the thermodynamic behaviour of water is ignored and the matter only considered in terms of radiation. IMO a basic flaw in the IPCC logic, now being used in the models.

In reality water provides a strong net NEGATIVE feedback, due to absorbed radiation energy being converted to Latent Heat at CONSTANT temperature in the evaporation process.
This is what happens in the clouds as the water droplets convert to vapor carrying this Latent Heat. Further: this vapor, being lighter than dry air moves up through the atmosphere for dissipation of its energy upwards with some going into space.
The process is independent of CO2 levels and acts in opposition to the GHE.

In the cirrus clouds at some -50C, nudging the tropopause, the fact that these ice crystals are growing means that there is a net transfer of energy to space until the mass of the crystal is such that gravity takes a hold and returns the water back to earth for the cycle to be repeated.
In this cycle (The Hydro Cycle) which acts as a Rankine Cycle it is known that any increase in energy input results in an increase in the RATE of circulation with NO increase in the MASS of the working fluid. This explains why humidity levels are not being seen to be increasing, in spite of global warming.

Incidentally: at the evaporation of water the Planck sensitivity coefficient is ZERO as it occurs at constant temperature. One may well ask whether this fact is incorporated into the model calculations of Global Sensitivity.
Overall; for every kilogram of water evaporated from the surface some 694 Watthrs of energy is driven up through the atmosphere and beyond for dissipation before returning to earth.
This done irrespective of CO2 levels.

Jim Gorman
Reply to  Alasdair Fairbairn
September 30, 2020 9:54 am

Alasdair –> A couple of things.

“Further: this vapor, being lighter than dry air moves up through the atmosphere” Lighter than air is kind of a misnomer. True the mass is smaller, but the weight is determined by gravity. What happens is that the energy absorbed from IR and collisions performs WORK against gravity and with an adiabatic process moves higher (less dense). Adiabatic processes are not necessarily isothermal so the molecule cools because its translational velocity slows due to loss of energy from the work performed against gravity (and probably from some collisions also).

At some point in the molecule’s travel, it will have cooled enough to condense and will give up the remainder of its absorbed energy. This will consist of remaining sensible translational energy and latent heat in the rotational/vibrational energy.

Alasdair Fairbairn
Reply to  Jim Gorman
September 30, 2020 10:36 am

I think you are getting a bit complicated here. It is the molecular weight that is the prime factor which provides the buoyancy we see in the vapor(gas)
A balloon filled entirely with this vapor has around twice the lift to that of a hot air balloon of equivalent size and about 60% of that of a helium balloon. OK – agreed it is difficult to maintain the vapor in the balloon without condensation; but the fact remains. It doesn’t take much lateral thinking to image parcels of skinless vapor balloons rising up through the atmosphere.
To me the energies and forces you refer to, are generally in all directions; so I can’t quite understand where you get the specific upward force as a result.
Agreed: Once the Latent Heat has been depleted by contact with the lower temperatures at higher altitudes, condensation occurs and the lift reverses to a falling. This is the point where clouds form and become visible. This can also occur at ground level where the atmosphere is at a lower temperature than the water where evaporation is taking place. We see this as the mist forming over say a slow moving river in still conditions.
My regards

Jim Gorman
Reply to  Alasdair Fairbairn
September 30, 2020 11:55 am

Gravity is the issue. Buoyancy no doubt has an effect. However, I expect it is small. No doubt even buoyancy exerts force over a distance thereby creating work. Otherwise the atmosphere would become very stratified very quickly based on molecular weight. Since it does not, molecular movement and energy is a bigger factor.

The big issue is the amount of work done and energy expended.

Loren C. Wilson
Reply to  Jim Gorman
September 30, 2020 2:00 pm

Gravity causes the buoyancy. Humid air weighs less than an equivalent volume of dry air. It therefore rises and expands. As it expands, it cools. This is a fundamental law of nature. The parcel of humid air also cools a tiny bit due to contact with and some mixing with cooler air higher in the atmosphere, but the major effect is adiabatic expansion and cooling. At the point where the temperature reaches the dew point temperature of the humid air, condensation begins and a cloud forms. As the water vapor condenses, it releases a significant amount of heat (approximately 44 kJ/mol of water – divide by 18.015 to get the heat of vaporization per gram). This heat keeps the cloud warm, allowing it to continue rising. This is how thunderheads form. The microscopic droplets slowly combine and then form rain drops. The cloud is radiating heat to outer space (and to the ground) all the time this process is going on. The question is the net effect of the cloud – there are several heat transfer processes going on at the same time.

Jim Gorman
Reply to  Jim Gorman
September 30, 2020 6:46 pm

Loren –> How does gravity exert a force upward? Do your physics analysis of forces.

I’m not arguing that denser air can’t exert an hydrostatic force upward, i.e., buoyancy. But air is not a liquid, it is a gas and exerts a lot less force.

If there wasn’t molecule motion as a gas, and only buoyancy, the atmosphere would stratify based on molecular weight with the heavier molecules at the bottom and H2 at the top.

Loren C. Wilson
Reply to  Jim Gorman
September 30, 2020 8:57 pm

Jim, in response to your question below, a helium-filled balloon on the space station just floats around. You float in water because gravity pulls the water towards the center of the earth. This force pushes sideways, which is why water will leak through the side of a tank. the sideways force causes the buoyant force on everything in the water, which is why you float in water. Hot air balloons float in the atmosphere and rise for the same reason that a mass of humid air does. Air causes buoyancy and you can measure this using a sensitive balance. (I have at work, many times). Weigh a one-liter filter flask complete with a stopper and at stop-cock on the side arm. Then evacuate it and seal off the side arm. When you weigh it again, it will weigh about1.2 grams less. This is the difference of the buoyant force on the flask before and after it is evacuated. It is equal to the mass of air displaced. As every sail plane pilot knows, warm air rises. This air rises because it is less dense than the air around it.

Alasdair Fairbairn
Reply to  Jim Gorman
October 1, 2020 3:38 am

I suggest it is not small. You only have to calculate the energy required to raise up the amount of water in say even a smallish cloud to realise that a lot of energy is involved. The force involved derives primarily in this buoyancy factor albeit in conjunction with convection where it is helpful. The altitude enables a value of the energy to be calculated.

Jim Gorman
Reply to  Jim Gorman
October 1, 2020 4:46 am

Loren –> “a helium-filled balloon on the space station just floats around” So do pens, pencils, wrenches, etc.

“When you weigh it again, it will weigh about1.2 grams less.” Have you ever wondered what air weighs? Also, grams are not a measure of force, they are a measure of mass.

Tim Gorman
Reply to  Jim Gorman
October 1, 2020 5:52 am

Buoyancy is derived from pressure. Pressure times area equals force.

In either a liquid or a gas the pressure exerted on something is based on the weight (i.e. mass times acceleration – usually gravity) of the column of liquid or gas above it.

Since the top of the “something” has less mass above it than does the bottom you see a positive pressure differential between the bottom and the top of the “something”. That pressure differential times the area of the “something” creates a force that pushes the “something” causing it to move upward. Force times distance equals work.

Humid air doesn’t rise because it weighs less than dry air. Humid air just rises faster than dry air because acceleration equals force divided by mass. Less mass (i.e. less weight) means higher acceleration. Even dry air will rise because of pressure differentials due to difference in air mass above and below it.

September 30, 2020 3:19 am

As seen in the graph above, this article shows that declining humidity in the upper atmosphere fully offsets the greenhouse effect of increasing humidity in the lower atmosphere.

The graph is about RELATIVE humidity. And what matters for the GHG effect is ABSOLUTE humidity. Relative humidity can go down whily absolute humidity stays the same, when the temperature increases. So please include a similar graph that shows ABSOLUTE humidity instead of that one.

Reply to  Nylo
September 30, 2020 4:56 am


Reply to  Nylo
September 30, 2020 9:43 am

Time plot of Absolute humidity at climate4you

Total column water in 1983 was 25 millimeters.
Total column water in 2020 is about 25 millimeters.
That’s about 0.25 percent, or 2500 parts per million.

Another view of absolute global water vapor that may be of interest

Antero Ollila
Reply to  bwegher
September 30, 2020 9:01 pm

Her is the TPW diagram and UAH temperature graphs.

Reply to  bwegher
September 30, 2020 10:21 pm

Thanks a lot bwegher! That graph is fantastic, although it stops in 2009 not 2020. It even explains THE PAUSE: atmospheric water vapour content was growing until 1998 and then became unusually low until 2009. It is clear that water vapour is waaaaaaay more important GHG gas than CO2, and that it does NOT get affected much by the increase in CO2. There are other phenomena causing its small variations. I would love to see an updated graph showing total water vapour column until today, I will look for it.

Antero Ollila
Reply to  Nylo
September 30, 2020 11:14 pm

Not quite up today but almost:

Reply to  Antero Ollila
October 1, 2020 5:37 am

Antero, that graphic in your link is at odds with the previous one, probably because it is showing absolute humidity at only some particular altitude range in the atmosphere instead of the total water vapor content. It would be nice to know the source of its data to really understand what it is showing. No source provided, no cookies.

Antero Ollila
Reply to  Antero Ollila
October 1, 2020 10:20 am

Sorry, not readily available with the TPW units.

Reply to  Nylo
October 1, 2020 4:17 pm

Hi Nylo,

I am the author of the paper at the link in the lead post. I did not write the lead post. The sentence was written by Anthony Watts, modified from a sentence in the Summary of the paper which is “This article shows that, based on humidity data from a major reanalysis dataset, declining humidity in the upper atmosphere fully offsets the greenhouse effect of increasing humidity in the lower atmosphere.”

The phase “As seen in the graph above” was Anthony’s words.
That graph is of relative humidity at various pressure level, and contrary to the quoted sentence, it does not demonstrate that the declining humidity in the upper atmosphere fully offsets the increasing humidity in the lower atmosphere.

If you read the paper, you will see that figure 6 shows TPW, being the total of humidity, and the effectice PW, which is the greenhouse effect of TPW. TPW is increasing while the effective PW is decreasing.
The page is at;

Is is found at the website, select “Climate Science” >> “The Greenhouse Effect”, 2nd item. Alternatively, see “Our Most Recent Article”, 3rd item.

Reply to  Ken Gregory
October 2, 2020 8:03 am

Hi Ken,

I read your paper when it first became available on FOS and found it very interesting in terms of how it ties to Miskolczi’s work.

A key question I have and not sure if you have an opinion:

Miskolczi through his analysis of historical atmospheric data and his theoretical work suggests that the Earth’s overall IR optical depth fluctuates around a constant value as the water column amount fluctuates. From the data and as indicated from your paper, we know that absolute humidity has decreased at higher elevations and increased at low elevations. Although overall IR optical depth impact may be zero, does the “absorbidity” profile change such that there still may some slight warming at lower levels. I recognize the relative effect of further humidity changes at low altitudes is much lower than at higher levels in the atmospheres but could narrowing of the optical window for instance cause some temperature increase?

September 30, 2020 3:22 am

I have no disagreements with Ken Gregory’s paper. A few more observations:

by Allan M.R. MacRae, B.A.Sc., M.Eng., June 15, 2019

1a. In 2008 I made the following major observations:
a. The velocity of changes of atmospheric CO2 [dCO2/dt] varies ~contemporaneously with changes in global temperature (Fig.1a).
b. Therefore the integral of dCO2/dt, changes in atmospheric CO2, lag changes in global atmospheric temperature by ~9 months (Fig.1b).

Later I was advised that Kuo et al (1990) made a similar observation to ‘b’, as did Keeling (1995), in papers published in Nature. Neither noted point ‘a’ above.

Kuo’s and Keeling’s findings have been carefully ignored for decades by the warmist camp – another “inconvenient truth”.

Fig.1a – The very close relationship of dCO2/dt vs global temperature is clearly apparent. Major volcanoes disrupt the relationship.

5. UAH LT Global Temperatures can be predicted ~4 months in the future with just two parameters:

UAHLT (+4 months) = 0.2*Nino34Anomaly + 0.15 – 5*SatoGlobalAerosolOpticalDepth (Figs. 5a and 5b)

Note the suppression of air temperatures during and after the 1982-83 El Nino, due to two century-scale volcanoes El Chichon (1982) and Mount Pinatubo (1991+).
Much of the atmospheric warming from ~1982-1996 (blue trend) was a recovery from the two major volcanoes – Nino34 SST’s (purple trend) cooled slightly.



7a. Why does the lag of atmospheric CO2 changes after temperature changes equal ~9 months?
In a perfect sine wave, the integral lags its derivative by pi/2, or 1/4 cycle.
There should therefore be approximately a (4 times 9 months = 36 months) 3 year average period in the data.
And there is – the inter-related datasets above show a ~3-year period, with the integral lagging its derivative by ~1/4 cycle.

September 30, 2020 3:31 am

3000 – 9000 metres? Most of the planet is way below that. Anyone who thinks they can separate TPW from TCW to any reasonable accuracy is playing with themselves. It’s laughable that they talk about RH% averaged over the entire planet. What a joke. The results from the satellite are a novelty and shouldn’nt be taken seriously in any scientific endeavour. Might as well lick your finger and test.

Erich Schaffer
September 30, 2020 5:26 am

This phenomenon is perfectly understandable, and if I get to finish my little series of articles on “notrickszone”, you might see how EVERTHING adds up perfectly. So far I have shown how the atmospheric GHE is ONLY 10K in size and how clouds are warming the planet, thus holding a fair share in these 10K. The implicit conclusion of course being, that GHGs can only be attributed with a meagre ~5K of GHGE.

Declining relative humidity is another of these head-scratchers if you still happen to believe in CO2 induced warming. Let us add it all up..

a) declining relative humidity
b) declining cloud cover (allegedly), thus more direct insolation
c) increasing temperatures
d) declining pan evaporation (!)

Pan evaporation for instance is influenced by a couple of factors. It is negatively correlated with rel. humidity, positively corr. with direct insolation and also positively with temperatures. Thus all these factors had to increase pan evaporation, but instead it is going the opposite way. How dare it!?

Given that CO2 has not the power to cause any significant warming and solar activity has stalled and declined over that last decades, we are still left to explain the recent autonomous warming of the planet, which mainly occured in the NH, and excluded Antarctica. Did we possibly forget something?

In theory contrails should be a potent driver of climate. We see warming in perfect accordance to where they occur and when they occur. Also contrails (or articifial cirrus clouds) reduce insolation to the natural water cycle underneath, thus reducing evaporation and drying up the air. Just saying..

D. Boss
September 30, 2020 5:53 am

Anthony, and all:

This analysis is flawed as is the whole “climate change is caused by CO2” mantra. But specifically this and almost all similar musings on humidity are deliberately misleading. Relative Humidity is a useless term, insofar as it relates to assessing the thermal balance of the atmosphere.

What is relevant is Absolute Humidity. Relative Humidity is a ratiometric term based on air temperature. A “relative” amount of water vapor cannot be deemed to affect actual thermodynamic properties. Only when you derive the Absolute Humidity can you then assign actual physically relevant numbers to it. (sensible heat, latent heat, heat capacity, enthalpy, etc)

For example right now at my location the air temperature at 20 ft MSL altitude is 75 deg F, and a relative humidity of 92%, and barometric pressure of 1012.7 millibar. You cannot calculate any relevant value for the thermodynamic properties of a cubic meter of that water laden air from the relative humidity. You must first convert the air temperature, relative humidity and barometric pressure to an Absolute Humidity value.

This online calculator does a fine job:

If you enter my location’s values, the Absolute Humidity is 27,689 ppm of water vapor, or 19.9 g/m³.

Now you can derive actual thermodynamic values from this Absolute Humidity.

The problem with all this “non-science” surrounding relative humidity diatribe, is it cannot yield physical numbers alone, and it obfuscates the fact that Water Vapor is THE dominant “greenhouse gas” on the planet!

Even technically illiterate regular folks would quickly realize the CO2 scam if everyone reported the Absolute Humidity in discussions of so called human caused climate change. Because the drumbeat has been OMG CO2 has risen to some 410 ppm – we’re all gonna die in a sauna (sarc).

Even dumb regular folks would quickly realize that if indeed water vapor is say 2x more effective at “greenhouse effect” (I hate that term, it’s really a blanket that regulates how rapidly energy is lost to space), and CO2 is 410 ppm but average water vapor (at my location) is right now 23,342 ppm from Jan 1 to present. Then the CO2/sky is falling myth would be obviously exposed.

I have been doing my own daily experiment since January, measuring the ground temperature, vertical clear sky temperature, and air temperature and absolute humidity at dawn every day. I’m using a decent IR instrument for ground and sky temps, and have cross checked it against known values. It does measure the vertical air column accurately to at least 27,000 feet altitude, as it accurately reflects cloud base temps against aviation METARS.

The ground temps plotted against absolute humidity is a straight line trend, with R^2 values of 0.96. Likewise I calculate the vertical clear sky radiative loss to space from the ground against absolute humidity, and it too is a straight line with R^2 of 0.96. (using the proper form of S-B equation)

I can predict what the ground temperature is given the absolute humidity and air temperature, or I can predict the vertical radiative loss from the ground given abs humidity and air temp, etc.

The radiative heat lost to space is governed by the water vapor content in an amount on average 97 times more than would CO2. The average radiative heat lost to space due to water vapor, is 175 W/m², while IPCC says CO2 does 1.8 W/m².

Arguing CO2 controls climate is a dumb as saying the excess heat developed by the alternator attached to your car’s engine is what causes the engine’s cooling system to overheat! Your alternator generates say 1.2 kW of electrical power, and is 60% efficient, so it produces 1.2/0.6 = 2 kW minus 1.2 kW = 0.8 kW of excess heat into your engine bay.

Your engine on the other hand produces on average about 30 kW (this is being generous – my 6,500 pound van with a 5.7 liter V-8 only needs 20 kW to maintain 65 MPH) of shaft power. it is about 27% efficient. So the engine produces 30/.27=111 kW total, and 111 minus 30 = 81 kW of excess heat on average.

So your engine produces 81 kW of excess heat, and your alternator only 0.8 kW, thus the alternator cannot ever “overheat” your engine’s cooling system.

This analogy is precisely the same as the nonsense of CO2 as earth’s thermostat in that CO2 is almost 100 times less actual “warming” than is the water vapor!

But I digress – Absolute Humidity is the only meaningful value of water content of the air, regards any discussion about the thermodynamics of the atmosphere!

Alasdair Fairbairn
Reply to  D. Boss
September 30, 2020 6:58 am

D. Boss.
You are dead right over absolute humidity. This value determines the Partial Pressure of water in the atmosphere at the water/air interface. The liquid water vapour pressure follows the trace of the vapour pressure V temperature graph. which shows that this pressure markedly increases exponentially at around 25C.*
The RATE of evaporation is a function of the difference between the Partial Pressure and the vapour pressure.
These figures , being absolute enable the calculation of the values of the enthalpies involved in the incoming radiation with that involved in the outgoing values due to evaporation . This being beyond my competence and resources.
May I suggest you look at this rather than at matters of radiation? I suspect that there is balance here and the two are more or less equal subject to other ancillary factors such as wind etc. For me it is the buoyancy of the vapor(gas) along with its Latent Heat that basically drives the system. All very complex.
My regards

* This goes some way to explain why the oceans rarely get much above 32C in spite of millions of years of relentless solar radiation.

Richard M
Reply to  D. Boss
September 30, 2020 7:09 am

You are correct and since high altitude absolute humidity has also decreased the point of the article is still correct.

Reply to  Richard M
September 30, 2020 9:33 am

Kudos for showing the climate4you graph.
Note that the high altitude absolute humidity in 1950 was 0.28 grams per kilogram.
The 2019 value shows high altitude absolute humidity at 0.27 grams per kilogram.

A one square meter column of atmosphere contains about 25 kilograms of water.
The total mass of the same column is 10130 kilograms. About 10 metric tonnes.
BTW, the CO2 is about 7 kilograms.

Reply to  D. Boss
October 1, 2020 5:09 pm

D. Boss,

Your comment is excellent and a very powerful one! I am clearly on the same page with you but you’re a few steps ahead! Please stay engaged but you have made some most valid points. If one is not playing around with an IR meter (mine is a 12/1 cone and about $50 bucks) they are not fully engaged. Absolute humidity is the only meaningful metric with regards to the energy levels of water vapor and the ultimate energy/heat release at the condensation level/phase change which may be a boundary of hundreds of feet or more.

Reply to  D. Boss
October 1, 2020 5:21 pm

D. Boss,
Please read the paper. You should comment on my paper only after you have read it. I used absolute humidity to evaluate the water vapour feedbacks.

Your statement “This analysis is flawed ” is false.

Richard M
September 30, 2020 6:59 am

The reduction in high altitude water vapor was predicted by Dr. William Gray decades ago. It was key to him becoming skeptical of the claims from the IPCC back in the 1990s.

As many have noted water cools the planet directly via evaporation, convection and radiation to space. Any warming of the planet enhances this process. The increased speed of the water cycle also increases condensation high in the atmosphere which is why we see the water vapor decreasing. This is a more subtle effect but in and of itself counters most of the warming from CO2.

Here is the latest summary of the late Dr. Gray’s views on climate change:

Gerald Machnee
September 30, 2020 7:22 am

***Water vapor increases with global warming and in the climate models it amplifies the direct small warming caused by anthropogenic greenhouse gas emissions. ***
This statement is wrong. Warmer temperatures increase the amount of water vapor the air CAN hold. There is no guarantee that there is more water vapor.
Has anyone shown that water vapor has increased in the last half century or so?
Then there is an assumption made in the MODELS.

Reply to  Gerald Machnee
October 1, 2020 4:31 pm

Gerald, the sentence you quoted is correct. In climate models, but not in the real world, water vapour amplifies the direct small warming caused by our greenhouse gas emissions.
Generally, increasing temperatures does increase water vapor absolute humidity in the lower atmosphere, but not in the upper atmosphere above 400 mbar. See table 3.

The second column of the table shows that a given change in the amount of humidity in the 300 to 200 mbar layer had 184 times the effect on OLR (the greenhouse effect) as the same change in the near-surface layer 1013 to 1000 mbars.

September 30, 2020 8:01 am

The main reason I come to this site daily is to appreciate how much I don’t know.

Thanks everyone.

Solomon Green
Reply to  Mr.
October 3, 2020 6:27 am

Mr May

I join you. My sentiments entirely. And, perhaps, when the experts here have decided whether increasing water vapour has the effect of heating or cooling the surface temperatures they will let me know.

BECAUSE if the idiots who are bent on replacing petrol, diesel and gas engines with hydrogen engines, particularly those in GB and EU, get their way we are going to have a lot more water vapour around.

Alasdair Fairbairn
Reply to  Solomon Green
October 3, 2020 9:08 am

I agree too. The thing about Quora is that you not only learn a lot; but you get a holistic view of all the befuddlements and attitudes and can often identify those who have been infected by the CAGW virus. You also get a view on your own befuddlements and on how much you do not know . A salutary exercise. The psychology is fascinating; sorting out the pontificators, those suffering from Cognitive Dissonance and the parrots.
My gratitude to all.

Alasdair Fairbairn
Reply to  Alasdair Fairbairn
October 3, 2020 9:11 am

Sorry folks I really meant WUWT. NOT Quora although the same applies in many respects. My bad- forgot where I was.

September 30, 2020 8:16 am

Is that my imagination or does the global relative humidity in the 300 and 400 mbar levels correspond to the “warming pause” ?

September 30, 2020 8:36 am

The lead post has generated a lot of good comments.

I’m glad to see a number of commenters express the need to use Absolute Humidity as a measure of atmospheric energy contained in water vapor rather than Relative Humidity which is such a vague term where the energy levels are concerned.

I use graphical charts for my check on weather/forecasts and keep an eye on the dewpoint and dumped the RH as it cluttered the graph.

September 30, 2020 9:34 am

If climate change is beneficial, then why is less global warming producing more benefits?

3.2 C had -$1.79, while 1.7C has -$7

Reply to  MikeN
October 1, 2020 4:55 pm

Hi MikeN, The paper linked in the lead post which I wrote, shows that the social cost of carbon dioxide with ECS = 3.2 C is -$1.79/tCO2. That means the social net benefit of CO2 emissions is +$1.79/tCO2. The paper shows, assuming the NOAA dataset is reasonably accurate, the the warming experienced to date have not caused a positive water vapour feedback. Eliminating that feedback reduces the ECS to 1.7 C and increased the social net benefit of CO2 to +7.14/tCO2.

Yes, slower warming is beneficial at both 3% and 5% discount rates, see table 5. At slower warming but the same CO2 emissions, we continue to get the benefits of CO2 fertilization of plants and crops, and we push the harmful effects of warming far into the future where is is greatly discounted.

I am only referring to the radiative feedbacks of water vapour, including the related lapse rate feedback. This says nothing about the changes to convection or to evaporation and precipitation. Warming should also cause a strong negative feedback from a more vigorous water cycle.

September 30, 2020 9:54 am

D. J. Hawkins said:”….there is no need to justify or explain natural cycles.” +1 Unless they don’t fit in to your theory.

September 30, 2020 9:56 am

Direct link to the Ken Gregory pdf, which is excellent BTW

Everyone should understand the difference between absolute humidity and relative humidity.
They are not the same thing.
Total Precipitable Water (TPW) is one way to express absolute humidity.
Global average TPW has not changed significantly in decades, which is absolute proof that global temperature has not changed in decades.

September 30, 2020 10:51 am

“The negative signs indicate that climate change is beneficial.”

I get a little tired of physical scientists of various kinds talking about “beneficial” (or otherwise) in respect to some physical number, driven by ignorant alarmism. Benefit/cost is TO LIFE. We need to remember the studies of paleontologists that concluded warming up to 6C means more abundant life and more biodiversity. We need to remember and use the term “climate optimum,” meaning warm period.

But I have seen the IR graphs from Organic Chemistry 2, and the huge one from -OH. I have been wondering how much water vapor is in the air, compared to .04% CO2. So I am keeping this article.

Phil Salmon
September 30, 2020 11:11 am

Two important articles by Erich Schaffer over at NoTricksZone; the second one uses a new data source, aviation flight weather records, to come to a surprising conclusion – the net effect of clouds is warming, not cooling. But – this is bad for warming climate models which assume the opposite.

Something like enthalpy energy has been overlooked.

Steve Z
September 30, 2020 2:15 pm

The original article says that “relative humidity” has been declining at the 500 – 700 mb levels of the atmosphere (although 700 mb looks rather stable since 2000, and 600 mb looks stable since 1990), while it has been increasing at the 300 – 400 mb levels recently.

But “relative humidity” by definition is the ratio of the actual mole fraction water vapor to the mole fraction water vapor at saturation, where the latter depends strongly on temperature. For example, the vapor pressure of water increases by 7.7% from 50 F to 52 F, so that warming the air by 2 F (1.11 C) would decrease the relative humidity by about 7.2% for the same amount of water vapor in the atmosphere.

So, if the relative humidity increases slightly, is this due to an increase in the actual mass of water vapor in the atmosphere at a given altitude, or a decrease in temperature at the same altitude, or a combination of both? Relative humidity is a poor measure of water content, since it depends on two variables (water content and temperature) which affect it in opposite directions.

Such data would be more meaningful if given in terms of absolute humidity, or mass water vapor per unit volume of air.

Reply to  Steve Z
October 1, 2020 5:11 pm

Steve, you obviously did not read the paper. Just because Anthony chose to put figure 3 of the paper as the lead image of the post, doesn’t mean I used relative humidity to evaluate the water vapour feedback. See table 1 which gives trends of absolute humidity. Figure 4 shows absolute humidity. Table 2 shows trends of absolute humidity by atmospheric layer. The key figure of the paper, figure 6 is of total precipitable water vapour (TPW) and the greenhouse effect of it, Effective PW, which is based on absolute humidity of each layer.

Reply to  Ken Gregory
October 1, 2020 6:40 pm


I read your paper and thought it to be very interesting and you put a lot work into it. Your Table 3 was quite interesting and I hope to go over it again when I have time. Some of the other commenters my have ‘cringed’ when seeing a couple of charts using relative humidity but would agree with your paper as a whole. Some of us read a lot of the links in comments and articles and ‘relative humidity’ makes me cringe and often I just move on.

September 30, 2020 2:26 pm

This brief post is very important. Soon I will post my 30-years of precipitable water vapor measurements (4 Feb 1990 to 2020). My data affirm this post, but for the full water vapor column.

Alasdair Fairbairn
Reply to  Forrest M. Mims III
October 1, 2020 2:47 am

Will look forward to that Forrest.

William Haas
September 30, 2020 5:30 pm

For those that believe in the radiametric greenhouse effect despite the fact that the radiametric greenhouse effect has not been observed anywhere in the solar system, it is a fact that H2O is the primary greenhouse gas in the Earth’s atmosphere. Molecule per molecule, H2O is a stronger absorber of IR than is CO2 and on average there is 50 times more H2O in the atmosphere than is CO2. The theory is that CO2 warming causes more H2O to enter the atmosphere which causes more H2O to enter the atmosphere causing even more warming and so forth. However, besides being the primary greenhouse gas, H2O is a major coolant in the Earth’s atmosphere moving heat energy from the Earth’s surface, which involves mostly some form of H2O, to where clouds form and more readily radiate the heat energy to space. The overall cooling effect of H2O is evidenced by the fact that the wet lapse rate is significantly lower than the dry lapse rate allowing more heat energy to more easily move to higher altitudes where it is radiated out to space. So H2O actually operates as a negative feedback reducing any warming that CO2 might cause.

A researcher from Japan pointed out that the calculations of climate sensitivity of CO2 not including feedbacks neglect the fact that a doubling of CO2 in the atmosphere will cause a slight reduction in the dry lapse rate in the troposphere which is a cooling effect that reduces the climate sensitivity of CO2 by more than a factor of 20 so instead of 1.2 degrees C, a better estimate of the climate sensitivity of CO2 is less than .06 degrees C. When one includes the negative feedback of H2O, the climate sensitivity of CO2 is effectively zero. So there is good reason why no one has been able to measure the climate sensitivity of CO2 or detect a radiametric greenhouse effect anywhere in the solar system because there is nothing to measure of detect. It is all a matter of science.

Alasdair Fairbairn
Reply to  William Haas
October 1, 2020 2:43 am

An excellent analysis. There is little doubt in my mind that water provides a strong NEGATIVE feedback to the GHE or indeed any increase in global energy input.
There now seems to be a universal view that water, being a greenhouse gas (GHG) serves to warm the planet. The statement crops up repeatedly both in alarmist and sceptical literature.
In fact the opposite is true in spite of it being a GHG.
This is due to the evaporation process which occurs at constant temperature giving the Planck sensitivity coefficient a value of Zero. Thus any energy absorbed by water does NOT result in a temperature increase as would be the case with other GHGs.
Further the process serves to move this absorbed energy up through the atmosphere for dissipation both in the atmosphere and space to enable a global energy balance.

The assumption that water tends to warm the planet due to its POSITIVE feedback is a fundamental FLAW in the IPCC logic.

September 30, 2020 6:15 pm

This article started about TPW and then went on with relative humidity at the 300,400,500,600, and 700 levels. What’s up with not mentioning what’s happened between the 700 level and the surface?

Tom Abbott
October 1, 2020 10:17 am

I see “The Science” of CO2-caused Climate Change is still not settled.

We should not be spending Trillions of dollars on windmills and solar and giving up fossil fuels based on such uncertainty.

Ulric Lyons
October 1, 2020 5:42 pm

Surely the changes in water vapour alters the amounts of solar near infrared absorption at various altitudes? Less water vapour in the upper atmosphere would reduce the NIR absorption there, and more water vapour in the lower atmosphere would increase the NIR absorption there.

Farquhar Knell
October 2, 2020 7:12 am

I would like to suggest to the Climate Science education community that the first sentence, at the first lecture, on the first day of a course should be:

“It’s the water, stupid!”

That way, the students might evolve into scientists that question everything they’re told, instead of parroting the almost unhinged rantings of those who choose to believe that CO2 is the climate’s control knob.

One especially egregious notion that deserves to be immediately skewered by some high school-level science is the notion that “the atmosphere, poisoned by that dreaded gas, is warming the oceans and making them rise”.
Oh, really? Perhaps those who believe that should consider the following: a cubic metre of water – which covers 70% of the earth – contains more than 4800 times as much heat as a cubic metre of air. On average, the sea is at a temperature 2C higher than the air above it, therefore, according to fundamental thermodynamics, the direction of heat transfer is almost invariably from water to air. Every meteorologist knows this, but it seems climate scientists don’t, or at least choose to ignore it. Even in the rarer circumstances of temperature inversions, how much heat could the air hope to transfer to the sea, given that gases are piss-poor heat radiators at low temperature differences and little better at conducting heat?

I propose that every competent, non-ideological science teacher should get his 16-year old numerate students to do this exercise for themselves, and see what a crock this whole business is. For further disenchantment with climastrology they could then do the same exercise with radiation. Even allowing for the fatuous belief that “it’s the backradiation of 333W/m2 doing the warming”, since most commentators don’t even realise that this is simply a radiance temperature, and not a measure of heat transfer except to a sink at 0K, if they do the numbers and see that at 333 joules/sec the air parcel would lose 1C of temperature every 3 seconds, and very quickly stop transferring, having achieved an unmeasurable heating effect on the water.

Only the sun has the power to heat the sea, and it’s time the world woke up to this simple fact. (It’s also the principal factor in melting ice, but that’s for another time).

Alasdair Fairbairn
Reply to  Farquhar Knell
October 2, 2020 12:06 pm

Some very good and fundamental comments here. Thanks I could query some details but that’s science is it not? The educational system indeed needs a good shake up as it has a lot to answer for.

M. Thompson
October 2, 2020 7:21 am

Where is Miskolczi in all this discussion.

My “go to” graph on the climate fraud:

comment image

Note that consistent with this graph, the relative humidity at 300 and 400 mb is because we moved from a deep La Nina to a strong El Nino. Miskolczi’s graph where water column spikes is consistent with El Nino’s and volcanic eruptions!

October 2, 2020 7:25 am

Where is Miskolczi in all this discussion?

My “go to” graph on the climate fraud:

comment image

Note that consistent with this graph, the relative humidity at 300 and 400 mb is because we moved from a deep La Nina to a strong El Nino. Miskolczi’s graph where water column spikes is consistent with El Nino’s and volcanic eruptions!

October 2, 2020 9:41 am

Show your work on the 4800 claim.

Specific heat of air is 1kJ per kg.
Specific heat of seawater is 4kJ per kg.
By mass, seawater will change temperature 1/4 as much as the air above changes.
By volume, density of seawater is 800 times greater than air at the surface.
800 times 4 is 3200
To raise one cubic meter of seawater by 1 kelvin requires 3200 times more energy than the air above.

Farquhar Knell
Reply to  bwegher
October 2, 2020 5:29 pm

You’re right – I chose to use volume rather than weight in my calculations, because radiative transfer from a surface is always expressed per square metre, and I foolishly used someone else’s dodgy specific heat figure for air in my conversion.

Therefore, heat content of Cubic metre of water at 15C: 1000kg x 4.184kjoules/kg*K x 288K=1.205 million kilojoules.

1 cubic metre of air at 15C: 1.225kg x 1.005kjoules/kg*K x 288 = 355kjoules

So, only 3,394 times the heat content: that is, a cubic metre of water contains the same heat as a metre square column of air 3,394 metres high. Hmm, but at that height, the air is going to be at least 16K cooler. So, lets just round up to 3,400, shall we, while we consider how much heat is available to be transferred downwards from this column into the water, which is almost always at a higher temperature and prone to doing a bit of heat dumping of its own down this largely one-way street.

Yet another factor that needs to be borne in mind is that if you look up any aspect of radiative physics, one of the first words one encounters is “surface”. Because surfaces of solids and liquids (and even water droplets and small particles) can emanate substantial radiation, with a host of tightly packed atoms/molecules standing behind the surface ready to re-equilibrate any energy lost to cooler sources.

Gases? Not so much. Radiative emission from gases only becomes significant at high temperature differences, such as in furnaces, and at the upper levels of the atmosphere, where CO2 is able to dump the modest heat it still contains at -50C to the horror of space at -270C.

The notion of backradiation as a key plank of the AGW scare is an insidious piece of nonsense that has received far too much attention. After all, we live in a world of backradiation, where everything we know is radiating to everything else in its field of view; and energy transfer from warmer to colder substances is happening continuously in the inexorable quest for equilibrium. The exception is space, the closest thing we have to absolute zero, and of which there is rather a lot. Only space allows significant radiative transfer from gases. In the modest temperatures on earth and above it, the greenhouse gases can only absorb a bit of IR energy and move it around via their fellow atmospheric constituents (N2, O2, H2O), mostly upwards.

Reply to  Farquhar Knell
October 2, 2020 8:13 pm

Specific heat capacity of SEAWATER is 4.005 kilojoules per kilogram K.
Density of SEAWATER is 1026 kilograms per cubic meter.
1026 times 4.005 is 4109.
You don’t need to multiply by 288 because the temperature INTERVAL for both air and seawater is 1.000 Kelvins.
1.225 times 1.005 equals 1.231
4109 divided by 1.231 is about 3338

Values from engineering toolbox