Guest post by Wim Röst
Abstract
The Earth’s greenhouse effect is much larger than suggested so far. If surface radiation and the greenhouse effect set surface temperatures, our oceans would be boiling. Fortunately, they don’t. Water Earth has a strong water-vapor-based evaporative surface cooling mechanism that effectively sets and stabilizes surface temperatures at a much lower level than cooling by surface radiation emissions can do. Thanks to water vapor our temperature system is far more stable than admitted by the consensus, and thanks to water, water vapor, and clouds surface temperatures are favorable for present life.
Introduction
Early Earth consisted of hot molten lava covered by an extreme greenhouse atmosphere: hardly any surface radiation could reach space, if any. Nevertheless, its surface cooled. Upward convection brought sensible and latent heat from hot surfaces to elevations on the very edge of the atmosphere from where energy effectively could be radiated into space. Despite the near maximal greenhouse effect the surface of Early Earth cooled down and at a certain moment the first oceans developed. Those boiling oceans still resulted in a huge upward convective transport of energy, further cooling the surface. Until now, convective upward transport of energy plays the main role in surface cooling. Convection sets and regulates surface temperatures at actual level. Without evaporative-convective-cloud-cooling, our actual greenhouse atmosphere would theoretically result in a surface temperature of 202.3°C. On the real Earth the greenhouse effect warms the surface, but greenhouse warming does not set and control final surface temperatures. Earth’s H2O-based cooling system does.
Theoretical greenhouse effect
We can calculate the warming effect of present greenhouse atmosphere for a theoretical planet[1] in the case where its surface is cooled just by radiation. Without a greenhouse atmosphere and if optimally cooled by radiation[2] the temperature of such a theoretical planet is minus 42.3 degrees Celsius. But a greenhouse atmosphere makes a huge difference. Initially.
Present Earth’s greenhouse atmosphere is still ‘a near perfect’ greenhouse atmosphere. As shown in Figure 1, only 22 W/m2 of surface radiated energy (396 W/m2) can reach space without being absorbed. A surface cooling efficiency of only 5.556%.
The efficiency of cooling by surface radiation is very low: after absorption, nearly all surface emitted energy returns to the surface as downwelling radiation or (without convection) and stays as sensible heat in the lower atmosphere. Knowing the cooling efficiency of the Earth’s surface radiation, we can calculate the greenhouse surface temperature in the case where the surface of our imaginary planet is only cooled by radiation, as shown in Figure 2.
With Earth’s present greenhouse effect, the surface of our imaginary planet would have had a temperature of 202.3 degrees Celsius, if only cooled by surface radiation. Total initial greenhouse warming is huge, see Table 1.
Given the high initial greenhouse warming effect, on our relatively cool Earth other factors than surface radiation must control the level of surface temperatures; probably H2O-related surface cooling.
The level of Earth’s surface temperatures
Where in the range of ‘greenhouse temperatures’ do we find Earth’s surface temperatures? On Earth, surface temperatures are best indicated by the surface temperature of ocean water, covering 71% of the Earth’s surface. The maximum average yearly temperature is 30°C while the minimum temperature is minus 1.8°C, shown in green in Figure 3.
‘Radiation only’ would have stopped cooling the planet’s surface at 202.3°C. Actual Earth yearly average surface temperatures are much lower, about 15°C. On real Earth, additional cooling by evaporation, conduction, convection and clouds has lowered surface temperatures far below the level ‘radiation only cooling’ would have resulted in. Why? The answer is that H2O-related cooling (evaporative, convective and tropical cloud cooling) is very strong, very dynamic, and very effective in the temperature range above 15°C.
Evaporation
Evaporation rises by 6-7% (Clausius-Clapeyron) per degree of temperature rise, a huge percentage. In the higher temperature range evaporative cooling cools extremely: think about boiling water of 100°C. In case of temperatures lower than 15 degrees Celsius, evaporative cooling diminishes by the same high percentage of 6-7%. At some point H2O related surface cooling and warming resulting from surface solar absorption came into balance at 15°C.
Convection
Convection in the atmosphere is the upward transport of latent and sensible heat from the surface to higher elevations. Convective removal of surface heat effectively cools the surface and brings energy to elevations lacking most of the main greenhouse gas, water vapor. At these elevations emission to space is more effective than surface emission. Convection is highly stimulated by the low-density water vapor molecules resulting from evaporation. Evaporative-convective cooling is huge in the higher temperature range and produces large quantities of solar reflecting tropical clouds. When tropical clouds develop, evaporative surface cooling is combined with diminished surface solar warming: very effective.
Conduction
Strong convection firmly enhances wind over the surface and brings in drier and colder air from elsewhere, resulting in higher conductive surface heat loss.
Diminishing H2O-based cooling
The whole evaporation-based cooling machine is very dynamic. All H2O-based surface cooling is fueled by rising evaporation, as temperatures rise. But evaporation also strongly diminishes when temperatures fall, even by just one degree, ending further cooling of the surface. At present, the Earth’s[4] total surface cooling and total surface warming are balanced at a yearly average of 15 degrees Celsius.
Solar radiation
The oceanic uptake of solar energy is very dependent on the presence/absence of tropical clouds. As temperatures go down, lower-level tropical clouds diminish strongly, and more solar energy is able to reach and warm the surface. Surface warming causes a rise in evaporation. Rising evaporation, thunderstorms, and related processes ending in tropical clouds soon end the extra solar warming. Hence the incredible stability of the Earth’s surface temperatures.
Balance
At 15°C there is a balance between surface warming by solar uptake and surface cooling. Any further surface cooling results in higher solar uptake, neutralizing initial cooling. And any surface warming results in higher evaporative-convective-cloud cooling, neutralizing any initial surface warming.
Initial warming by extra greenhouse gases is fully neutralized like all other surface warming. Neutralizing warming happens at different time scales, sometimes seconds (radiation) or hours, a day, or by season, but often over decades (by longer-term ocean oscillations) and sometimes over even longer periods like the recovery from the cold Little Ice Age which might take centuries.
Why 15°C and why not 202.3°C?
Radiative cooling is less dynamic than H2O based cooling. For one degree of difference in surface temperature, radiative cooling goes up or down by only 1.4%, but H2O- based cooling by 6-7%. Early Earth started hot and then cooled down after its creation. At a current surface temperature of only 15°C (the temperature level for this geological period and for this orbital setting) the H2O related surface cooling has balanced surface solar absorption.
Early Earth
Early Earth was hot and steamy. Heat of accretion did melt all the colliding material coming from space that formed the Earth. A nearly perfect sphere formed and its atmosphere was the perfect greenhouse atmosphere: an atmosphere with a superhigh water vapor content, very rich in carbon dioxide, and a sky covered by clouds. Hardly any surface radiation could reach space without being absorbed. Convection had to transport surface energy to the edge of the steamy atmosphere where spaceward emission could take place. For early Earth surface cooling depended on the strength of convection. As temperatures fell, convective cooling continued but continuously diminished in strength. Tropical cloud coverage also diminished, allowing the Sun to warm the tropical oceans. Despite Earth’s huge greenhouse effect, surface temperatures have never been dependent on the strength of the greenhouse effect but on the temperature set by where H2O-related surface cooling balances warming by rising surface solar uptake.
Intrinsic properties
The fascinating H2O molecule has many intrinsic properties. One of its properties gives the molecules a strong cohesion resulting in a strong surface tension which creates ‘tight’ surfaces some insects can even walk on. Strong surface tension makes it difficult for a surface molecule to escape into the atmosphere, which raises the temperature at which enough water vapor will be released to cause ‘super-convection’. Another intrinsic property sets the freezing temperature at zero degrees Celsius and not at +10, +20 or minus 20 degrees. Binding one oxygen atom to two low-density hydrogen atoms results in a low-density water molecule, so very humid, low density, air easily rises. H2O’s intrinsic properties determine all essential elements of Earth’s main cooling system, which is dominated by H2O. The properties are intrinsic to the molecule itself: they don’t change over time. Therefore, the surface temperature of the Earth could have remained at the same level over billions of years if Earth’s orbital settings and the distribution of oceans and continents over its surface hadn’t changed. H2O’s intrinsic properties set the level of Earth’s surface temperatures for every specific orientation and surface arrangement of the Earth. The H2O molecule, nothing else.
Faint young Sun paradox
During the first years of early Earth, the Sun’s output must have been about 30 percent less intense as nowadays. Less solar energy reached the Earth. Nevertheless, the surface of the Earth has never been much colder than present Earth. This is called the faint young Sun paradox. Knowing the role of H2O-related surface cooling, that paradox is solved. As total insolation reaching the surface is controlled by tropical clouds and the Earth’s surface temperatures are controlled by H2O-related surface cooling, the Earth’s surface temperatures don’t simply depend on the intensity of solar irradiation reaching the Earth. In the case of a faint Sun, evaporation diminishes, less tropical clouds cover tropical oceans and enable more (but weaker) solar rays to reach and warm a larger surface area. End result for tropical oceans: about the same.
No Snowball Earth
Because the quantity of insolation reaching the surface is controlled by tropical clouds and because of H2O-controlled surface cooling, no complete snowball Earth has probably existed. A slightly colder surface strongly diminishes H2O related surface cooling. Diminishing tropical clouds result in a higher uptake of solar energy by tropical oceans. The final result is tropical oceans still remaining warm. On water Earth no full snowball Earth is possible. Even when all present land (29% of the total surface) is concentrated on both poles, the result is just a partial snow- and ice-covered surface. Most of the other 71% of the surface will be covered by relatively warm oceans, oceans that are redistributing tropical absorbed solar energy over mid-latitudes, not hindered by any continent.
Conclusions
The Earth’s greenhouse effect is huge, much higher than normally assumed. If cooled by ‘surface radiation only’ the surface of a theoretical planet would have had a surface temperature of 202.3°C. But the Earth’s surface temperatures are not set by the strength of Earth’s greenhouse effect. Additional H2O-based cooling systems keep the surface at a much lower temperature, balancing rising surface radiation uptake. At present, that balance is reached at a yearly average of 15 degrees Celsius.
Thanks to H2O-related surface cooling the Earth’s surface temperatures are bound to a narrow range, at a temperature level well suited for life on Earth. Due to its stability, life developed over many hundreds of millions of years.
Temperature regulates the cooling system; the cooling system regulates temperature.
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With regards to commenting, please adhere to the rules known for this site: quote and react, not personal. And when commenting, please don’t use abbreviations but words
About the author: Wim Röst studied geography in Utrecht, the Netherlands. The above is his personal view. He is not connected to firms or NGO’s or funded by government(s).
Andy May was so kind to correct and improve the English text where necessary or helpful. Thanks!
Footnotes
Calculations are for a theoretical planet fully responding to Stefan-Boltzmann Law. The theoretical planet is a perfect absorber/emitter (blackbody) and consists of an ‘infinitely thin shell’ not able to store any energy. Its surface is superconducting, resulting in the lowest emission temperature possible.
Calculated for actual solar surface absorbed (161 W/m2) assuming maximal absorption and maximal emission and assuming all surface radiation is directly radiated to space, meaning: without being absorbed. Efficiency of surface emission is 100% or an effective emissivity of ‘1’. Calculation by Stefan-Boltzmann calculator.
- This 2011 version of the graphic is the corrected one. The caption on the image: “The global annual mean earth’s energy budget for 2000–2005 (W m−2). The broad arrows indicate the schematic flow of energy in proportion to their importance. Adapted from Trenberth et al. (2009) with changes noted in the text”.
- The present state of the Earth includes the Earth’s orbital configuration and the location, size, and topography of continents and oceans. The total state results in a specific distribution and redistribution of solar energy over latitudes. Weather patterns depend on the distribution and redistribution of solar energy. Climate by definition is the average of 30 years of weather. Changes in climate are the result of changes in the distribution and redistribution of solar energy over the Earth’s surface.
Now reduce evaporation by polluting the marine/atmosphere interface with a thin coating of light oil and/or surfactant.
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Don’t we make oil and surfactants out of marine algae? Algae have been around a long time. How would that be possible if they had not spent the first billion years evolving to control the ocean temps.
Ocean gets hot, algae release surfactants. Too cold, algae release oil. By controlling marine evaporation algae control the earths temp.
Human hubris to think evolution hasn’t already been their done that.
I’m sure you’re right about biological manipulation of the ocean surface.
Oil and surfactant have the same effect. I was surprised to find that both smooth. But I there are warming and cooling mechanisms which phytoplankton use to modify temperatures – see the pale blooms of Emeliania huxleyi.
JF
Lovelock was wrong. Oceana rules our planet, not Gaia.
The critical insolation level is around 395W/m^2 to avoid snowball with the existing atmospheric mass. It presently peaks around 440W/m^2 in the tropics.
The reason Earth is not a snowball is the ability of the atmosphere to partition.
Can you estimate the water surface temperature in the photo below.
Rick Will: “Can you estimate the water surface temperature in the photo below.”
WR: That is a funny question. I would like to know a lot of things: the latitude, is there a continent nearby, is it the east side or the west side of an ocean (upwelling or downwelling water), is it the start of the day or the end of the day etc. I saw clouds like the high one in the middle, diminishing in height some two and a half hours before Sunset. It was 20 kilometers from the sea, and temperatures on land were going down to 23, 24 degrees. Clouds flattened out.
Why are there the rising fluffy clouds in the photo above a bed of cloud?
That is the important observation to understand.
The clouds are over water. The temperature of the water surface can be determined within a couple of degrees by the appearance of the clouds. They are just in the transition zone to cumulus.
If they are rising: surface temperatures should be 25, 26 degrees or higher.
The reason I think Earth was never a snowball has to do with the lowest cloud area fraction. As the following graphic shows, the cloud area fraction is lowest around 25 degrees of sea surface temperatures. My idea: this probably has to do with the Hadley cells: large high-pressure cells over the subtropics result in descending air and as usual in high-pressure cells: clouds are lacking. Average yearly sea surface temperatures: around 25 degrees (my guess). This confirms more or less what I see in summertime over the mid-latitudes: morning clouds disappear at least partly when temperatures rise above 20 degrees and above 26 degrees enhance in case the air is humid.
My guess is that around temperatures of 24-26 degrees a lot of Sunshine always is able to penetrate the oceans. Because of high evaporation salinity will be high. With ice over the poles, seawater around the poles will be relatively fresh: just a bit of evaporation, considerable rainfall, and desalinization by the formation of ice. Not much deep cold water will be formed Over the subtropical gyres I expect highly saline water to descend during wintertime at the poleward side. Considerable quantities of deep relatively warm water will be found between 40N and 40S and some warm water will be transported poleward over the surface. I expect no snowball Earth can be formed over the mid-latitudes, let alone over the tropics.
The plot is the result solely of atmospheric conditions over the water surface. It has nothing to do with sunlight penetration into the water.
The plot would be more instructive if it was showing relative humidity. It is quite evident by the constant presence of clouds around 0C. That means the relative humidity is very high.
So why isn’t the relative humidity high over most of the ocean. The troposphere is only 10km or so high but oceans can be thousands of kilometres from significant land masses. Why aren’t all atmospheres over oceans saturated?
This is the RH plot in global ocean atmosphere for a month. An important feature are the outliers that exceed 100%. Note there are none above 13C.
Not all the outliers are necessarily real because this is based on satellite sensing of precipitable water and that deteriorates with cloud cover. There is also a timing issue between what the atmosphere is doing relative to the surface temperature so there is potential for the RH to exceed 100% due to time lags and air movement. While supersaturated conditions do occur, it is unlikely that persists for a month because that would mean precipitation for a good part of the month.
It is also reasonably well known that the satellite data can have significant error to the low side over dense cloud. So the shallow minimum around 23C is less pronounced than what actually occurs.
About the graphic: which part of the air column is measured? The whole air column? And because the time period is a month, both ascending (humid) and descending (dry) columns will be measured. Only constant ascending columns will reach 100% or more. We need more information to be able to interpret the graphic well.
Why aren’t all atmospheres over oceans saturated?
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At a guess. The water vapor either rises because it is lighter than air or is wrung out of the air by falling temps at night..
Ocean surfaces temperature changes very little over night.
All rising air will eventually form cloud that insulates the surface from sunlight. And high humidity prevents further evaporation.
Wim Rost:
“The answer is that H2O-related cooling (evaporative, convective and tropical cloud cooling) is very strong, very dynamic, and very effective in the temperature range above 15°C.”
CORRECT: The reason why this is so is because the evaporation RATE of Water is a function of the Difference between the Vapour and Partial pressures prevailing at the water/atmosphere interface. A plot of these pressures at various temperatures reveals that at circa 30degC a rapid increase in this Rate occurs but WITHOUT increase in temperature.
The Enthalpy involved being converted to Latent Heat with a large increase in volume.
The volume increase renders the Vapor buoyant wrt. dry air resulting in rapid movement UP through the atmosphere for dissipation in the clouds with some to space.
At some 694 Watts/kg evaporated this swamps any incoming radiation which gets absorbed; rendering the Water unable to go much above this maximum 30degC value.
Statically this would result in a figure of around 15degC as an average or mean sea surface temperature, depending on how screwed the histogram was of the observed data.
This all occurs alongside any energy movements due to radiation alone and should not be confused with convective movement, being independent of temperature difference.
References:
1) The engineering Toolbox website.
2) The standard Phase Change graph.
3) The Steam Tables.
should not be confused with convective movement, being independent of temperature difference.
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Is convection not a result of density differences? Less dense air rises?
As far as I know, density differences are the driver of convective movements in oceans and in the atmosphere (if convective movement is defined as upward/downward movement of air resp. water). In the air, density differences occur because of temperature differences and/or differences in the quantity of water vapor in the air, in oceans (downward) convection results from lower temperatures and/or higher salinity. When temperatures in the oceans are more equal (when poles are warmer as in a Hothouse situation) salinity differences become more important and it becomes easier for the warm saline water of the subtropical gyres or from enclosed basins and/or from broad shallow coastal subtropical areas to form warm deep water – welling up again at the poles (by Ekman forces) and keeping the poles ice-free.
Alasdair: “A plot of these pressures at various temperatures reveals that at circa 30degC a rapid increase in this Rate occurs but WITHOUT increase in temperature.”
WR: Interesting. Do you have an example of such a plot? What exactly causes the rapid increase in the rate?
‘Evaporation rises by 6-7% (Clausius-Clapeyron) per degree of temperature rise, a huge percentage.’
This statement is correct, but at the same time it greatly underestimates the effect of water temperature on the rate of evaporation over the oceans. In addition to the direct affect of temperature on the rate of evaporation, the increased evaporation results in increased concentrations of water vapor, resulting in increased air density differences and thus increased wind. As the rate of evaporation increases linearly with the wind speed, the increased wind speed causes even more evaporation, resulting in a self-reinforcing feed-back mechanism. In addition when wind speeds become strong enough to cause waves with broken surface, the surface area available for evaporation can increase by orders of magnitude. Thus for a narrow range of temperatures, for example from 25C to 30C the rate of evaporative cooling from a given ocean surface can increase by orders of magnitude. This mechanism is what drives tropical storms.
In a recent post(1), Javier Vinós & Andy May presented – ‘6.3 ENSO: The tropical ocean control center’. I agree with this but would take it a step further. ENSO is the control center for the climate of the entire planet.
One must take into account that there are essentially 3 sources of energy input into the tropical Pacific :
ENSO balances the heat input from these three sources by oscillating between a low heat extraction phase (La Nina) and a high heat extraction phase (El Nino) in order to ensure a relatively stable climate in spite of the significant variability of various climate drivers.
And how does ENSO do this? Through the mechanism of Water Evaporation.
In fact ENSO is a natural oscillation between two unstable states :
1The Sun-Climate Effect: The Winter Gatekeeper Hypothesis (VI). Meridional transport is the main climate change driver, WUWT, 2022-09-04
And why do the trades bunch up into squall lines as you approach the itcz?
Mostly because the Sun is directly overhead and circulation there is nearly vertical, as the humid air rises to form storms.
Andy: Kudos to you and Javier for proposing a thought provoking Hypothesis of Meridonal Transport (MT) to the poles in winter as a major driving force of climate. The WUWT and JudithCurry websites provide a lot of interesting technical viewpoints, and many contribute valuable climate insights, like; yourself, Javier Vinos, Rick Will, CmoB, David Middleton, Wim Rost, Charles Rotter, Anthony Watts, Rud Istvan, and too many others to name.
The metaphor of the great climate discussion (unlike Koonin vs Dessler debate) being the “elephant analyzed by blind men” is totally appropriate for the myriad voices debating minutiae of obscure possible geophysics of the climate system.
Javier and you provide an excellent overview of related peer reviewed papers over the decades, that buttress and provide context for your MT hypothesis so as to deserve serious consideration.
The real clincher to consider is the correlation of delta Length of Day (dLOD) of about 2mS you identify during the 97CS, shown in your figure 4.5(g) plot. This appears to be a fully independent confirmation of a significant change of planetary angular momentum/energy. There are few other mechanisms that could produce this magnitude of energy change, other than gravitational effects or most plausibly gigatons of H2O migrating from low latitudes over time. By comparison the December 2004 Indian Ocean quake released about 40ZJ of energy and changed the LOD by only about 2.6 microseconds, or about 2.6 parts in 8.6 x10exp13.
Who knew that the Earth’s rotation might be interpreted as a signal of climate effects – a proxy or diagnostic of changes.
One kg of water vapor/ice crystals locally surface stationary at midday at about the Equator at ~12km high at the anvil head of a fully developed cumulonimbus cloud has a planetary tangential velocity of about 1,666 km/hr. If this 1 kg is transported towards e.g. the N pole then it will intercept the Polar Vortex effects at about ~50 deg N, so the angular momentum change is close to the square of the 1/cosine of the PV latitude (distance from earth’s axis), where this 1kg merges with the new longitudinal PV flow velocity. This is a rough estimate of Coriolis and mass flow effects. Integrating over the real mass flows and velocities provide huge angular momentum/energy changes that reasonably could modify planetary angular momentum around a mean value of LOD. Water and snow do not dead end at the poles, so conservation of mass requires some reverse effect over some cyclical time period to reverse this energy flow to balance the system- maybe climate?
The MT time constants are in the range of seasonal and climate effects that bedevil the clear analysis of so many overlapped; diurnal, lunar, solar, orbital effects that make it tough to order or prioritize the influence of different physical effects, to clearly predict or accurately model climate systems. Static TSI/TOA OLR energy balances are simply not realistic.
Your figure 4.2 plot of oscillation/periodicity modes of AMO, and the figure 4.3 Stadium Wave suggest that there is a clear set of interacting modes that correlate with Fourier components and phases and are not really random.
Following your and Javier’s hypothesis, may it finally be possible to better order climate science and energy flows with testable models, that properly include; clouds, water and latent heat transport, and so develop a truly useful and falsifiable “Grand Unified Theory of Climate” (GUToC) ?
I am not on any “side” of this issue. I simply have some formal training in physics, so follow Feynman’s effective admonishment that ‘anything that does not provide predictions that are not falsifiable by verifiable measurements is not a real theory’.
Thanks, good comment.
Doesn’t this bring us all back to… weather changes?
There is a probable mistranslation from radiative to thermal effect in an environment that emitted excess radiation after the first wave,
n.n. “a probable mistranslation”
WR: Where?
WR, thank you for such an interesting post. Well done!
Thanks! My pleasure!
“The Earth’s greenhouse effect is huge, much higher than normally assumed. If cooled by ‘surface radiation only’ the surface of a theoretical planet would have had a surface temperature of 202.3°C.”
Well, I would agree Earth greenhouse effect is huge, but mainly because some people might claim Venus greenhouse is huge- and I tend to think it is smaller than Earth’s greenhouse effect.
It seems we need comparison to get any meaning to the hugeness of Earth greenhouse effect.
I think Venus at Earth distance, would be quite cold compare to Earth as Earth has bigger greenhouse effect.
But it seems if Earth was at Venus distance, Venus would be hotter.
It is imagined the Venus ocean boil away {and it was very small ocean] and it seems rather unrealistic to expect Earth ocean to boil away, but one might expect Earth to have lot more clouds. And if have clouds, you one has cooling not of “surface radiation only” but mostly from all these clouds.
Or if gave Venus our ocean it would the cooling effect because had our ocean- And Venus would unable to boil way this vast ocean in billions of years.
Gbaikie, I prefer to focus on trying to understand the Earth’s cooling/warming system, but imagining Venus at the distance of the Earth from the Sun and with a comparable quantity of H2O molecules at its surface I guess that the huge convective H2O-based cooling system would rapidly cool its surface, probably to about the Earth’s temperatures, assuming no other clouds than H2O clouds would cover the sky. Venus now has clouds:
“Venus’ thick cloud layer forms at about 50 kilometres (km) from the planet’s surface, when sulphur dioxide from volcanoes combines with water to form sulphuric acid, one of the most corrosive substances in the natural world. Any remaining sulphur dioxide is rapidly destroyed by solar radiation above 70 km.” Source
In case huge H2O-induced convection would expose the sulphur dioxide clouds to solar radiation, that type of cloud could disappear. If not, the quantity of H2O clouds compared to Earth’s quantity probably would diminish, to enable more sunshine to reach the surface until the quantity of H2O clouds finally would be settled somewhere below the Earth’s quantity of H2O clouds. At a slightly lower surface temperature.
(just my first thoughts – not being a Venus specialist)
–Gbaikie, I prefer to focus on trying to understand the Earth’s cooling/warming system, but imagining Venus at the distance of the Earth from the Sun and with a comparable quantity of H2O molecules at its surface I guess that the huge convective H2O-based cooling system would rapidly cool its surface, probably to about the Earth’s temperatures, assuming no other clouds than H2O clouds would cover the sky. Venus now has clouds:–
And Venus rocky surface has very long day. And not much tilt.
Venus currently has 4 to 5 day rotation in the upper atmosphere, but it’s rocky surface has very long day. If Venus had same spin as Earth, it would like Earth at Earth distance with Earth ocean.
Or I assume, Venus atmosphere rotates because it’s heated in it’s upper atmosphere
[roughly 50 Km elevation] and it’s due to the intense sunlight at Venus distance.
Another way to look at it, is Venus absorbs 170 watt on average at Venus distance and it should absorb less sunlight at Earth distance.
Though Earth at Venus distance could absorb about as much or absorb less than Venus does.
Good points I think. I know, it is very complicated to compare planets. That is why the theoretical planet with the infinitely thin and superconducting shell is developed. As soon as we start making assumptions at only one point – let alone at two or more points – simplicity and ‘the simple view’ are gone and the result is susceptible to manipulation in the direction of the ‘wished result’, which does not say that by everyone ‘a wished result’ is at his/hers center of attention. But it becomes a path of ‘glissy ice’, especially for relatively laymen like me. So I tried to avoid complexity while still staying near the core of the system.
About other planets: I will be careful.
Some say Earth could become like Venus.
And one can assume they mean much hotter.
Maybe they mean colder. I don’t like idea of this Ice Age, become a lot colder. Though it seems it’s destined to become a bit cooler, as we a bit late into this interglacial period
gbaikie: “Though it seems it’s destined to become a bit cooler, as we a bit late into this interglacial period”
WR: I think so. Intermediate waters in the oceans show a long-term cooling trend, suggesting we are on our way to the next glacial. See for example:
Source
The lapse rate of the atmosphere is well known and all planetoids with an atmosphere thick enough have convective cooling which produces a lapse rate. So, to claim that the earths convective cooling is somehow unique is ridiculous. Venus has much the same processes, with a convective cooling up to clouds.
The problem is that the “greenhouse model” is a total load of useless twaddle and totally ignored the fact that in the majority of the atmosphere the rate of change as we leave the atmosphere, isn’t set by how much IR active gases are present, but simply that there is convection present.
“nearly all surface emitted energy returns to the surface as downwelling radiation or (without convection) and stays as sensible heat in the lower atmosphere.”
I’ve read a part of this post and agree with much of what I’ve read so far. This I don’t agree with. If sensible heat *stays* in the lower atmosphere then the atmosphere would continue to heat over time and the temperature would just keep rising. That doesn’t happen so that sensible heat is lost in some fashion or another; convection, conduction, or radiation; until an equilibrium point is reached.
This is probably just a nitpick but it could lead to misinterpretation by some.
Tim Gorman: “If sensible heat *stays* in the lower atmosphere then the atmosphere would continue to heat over time and the temperature would just keep rising”
WR: Correct, without convection the temperature keeps rising, if necessary to 202.3 degrees. Convection is the shortcut to elevations from where radiation can be radiated to space with a high efficiency: from where the main greenhouse gas water vapor is lacking. By evaporation, convection and clouds, the 202.3 degrees goes down to just 15 degrees.
I’ve wondered in the past as to what impact there would be on global temps if pollution or biolgical growth such as algal blooms caused the Earth’s oceans to be covered in a liquid that didn’t so rapidly evaporate.Wouldn’t his single process lead to a rise in the temperature?
Why is the contribution of nitrogen and oxygen to radiative heat loss never included? Neither may absorb LWIR but they both can gain energy from collisions with GHG’s. That energy *is* radiated by nitrogen and oxygen.. Is the amount just considered to be small enough to ignore?
The atmosphere, including nitrogen and oxygen, does absorb light energy. It’s why the sky looks blue, much of the other light frequencies are absorbed in the atmosphere. Is this all from water vapor? Or does nitrogen and oxygen play a part? This represents a gain in energy. Something happens to that energy. Doesn’t a portion of it get radiated back to space? Is that subsumed into the albedo factor?
It just seems that there are lots of other factors than just water vapor and GHG’s involved in the overall process and they never get discussed.
Tim Gorman: “Why is the contribution of nitrogen and oxygen to radiative heat loss never included?”
WR: Their contribution is but low, somewhere below one percent or so:
https://qph.cf2.quoracdn.net/main-qimg-1c0fe875a2200e4f68014292488a6f2d-lq
As you can see water vapor also absorbs shortwave energy: it must be an important factor in warming the atmosphere and in stimulating humid convective flows to rise faster. In the early morning when some cloud tops get the first Sunlight, those places are probably the first to form convective columns. Clouds and water vapor both absorb shortwave, part of it.
So water vapor is a coolant! This is consistent with the data from the tropics presented by Maria Hakuba from the JPL shown in the attached slide.
Is it any wonder why the hotspot in the troposphere predicted by climate models is missing?
Regarding “The efficiency of cooling by surface radiation is very low: after absorption, nearly all surface emitted energy returns to the surface as downwelling radiation or (without convection) and stays as sensible heat in the lower atmosphere”: The thermal radiation from the surface that is absorbed by greenhouse gases and clouds does not actually have 84.5% of itself (333/394) being returned to the surface by reradiation in the form of “back radiation”, and does not have only 5.556% of its outgoing radiation (22/396) escaping to space because the 22 W/m^2 figure is the non-stop subset of escape. The greenhouse gases and clouds have energy budget of 549-550 W/m^2, with about 39.5% of the 550 W/m^2 that they radiate being outward and about 60.5% being towards the surface. This means that about 51.1% (60.5% * 84.5%) of the thermal radiation from the surface gets reradiated back to the surface, and about 48.9% of the radiation from the surface either escapes into space unabsorbed (5.556% 22/394) or gets absorbed and reradiated into space by greenhouse gases and clouds (the other ~43.3 of this ~48.9%).
Warming of the surface by having 51.1% of its outgoing thermal radiation being returned to it would cause its temperature in Kelvin to increase by a factor of (1/.489)^.25, which is 1.196. Using the Stephan Boltzman radiation law, 161 W/m^2 with 100% emissivity means 230.84 degrees K -42.3 C, and with 48.9% emissivity means 276.04 K 2.89 C. (161 W/m^2 with 48.9% emissivity results in temperature same as about 329 W/m^2 with 100% emissivity.)
Add to this: Thermal radiation to the surface from greenhouse gases has not only about 60.5% of the 333 W/m^2 of radiation they receive from the surface, but also 60.5% of the 78 W/m^2 they absorb from sunlight. (This is oversimplified, the figure is slightly over 60.5% of radiation absorbed from below, somewhat less than 60.5% of radiation absorbed from above.) 60.5% of 78 W/m^2 is about 47 W/m^2, that plus 329 W/m^2 is 376 W/m^2. This is still oversimplified because I omitted non-radiant heat flows, some of which result in heating clouds and greenhouse gases and adding a few W/m^2 of radiation that the surface is receiving.
For a simpler calculation indicating a lower figure of effective surface emissivity: The surface is radiating 396 W/m^2 while receiving 161 W/m^2 of sunlight reaching it directly nonstop. This would indicate surface temperature of (396/161)^.25 times 230.84 K, which is 289.09 K / 15.9 C if the surface emissivity is 100% (a little more if the surface emissivity is less than 100%), and the according effective surface emissivity being about 40.65% of actual surface emissivity (161/396).
The strength of the greenhouse effect is shown by the share of surface emission reaching space uninterrupted: 22/396 = 5.556%. Any delay causes warming: 94.444% of surface emission has a delay which will be huge in case no evaporative-convective-cloud cooling exists.
Additional problem: dynamic evaporative-convective-cloud cooling is activated and de-activated according to the intrinsic properties of the H2O molecule. Not by the quantity of greenhouse gases in the atmosphere.
The delay from outgoing radiation being absorbed and re-radiated by greenhouse gases on its way from the surface on its way to space (for the ~39.5% of this absorbed/reradiated radiant heat that goes outward into space rather than being returned to the surface) is mostly microseconds or milliseconds. Meanwhile, evaporative and convective cooling of the surface combined are 97 W/m^2 (of 493 W/m^2 going out from the surface), while the surface receives 161 W/m^2 of sunlight. And, the 22 W/m^2 direct nonstop radiation route (13.66% of 161 W/m^2) indicates 58.55% warming from 230.84 K before accounting for indirect radiation routes, and the indirect heat escape routes mostly involve entirely radiation although a minority of this escape involves nonradiative heat transfer along the way.
At least 160 of this 161 W/m^2 received directly by the surface from the sun is leaving the planet/atmosphere and going into space by means of radiation, and the surface energy budget (including convection and evaporation) is 493 W/m^2. Even a calculation using these figures, with the 97 W/m^2 non-radiation surface cooling eliminated (and replaced by radiation from a warmer surface) but with the subset of the non-radiative surface cooling which gets radiated towards the surface by greenhouse gases and clouds not being eliminated, only results in an absolute temperature increase by 32.3% from 230.84 K to 305.36 K.
Donald L. Kipstein: The delay from outgoing radiation being absorbed and re-radiated (…) is mostly microseconds or milliseconds.
WR: Surface radiation by definition is upward and in case it reaches space cools the Earth and the surface. But only 5.556% of surface radiation reaches space. The rest is absorbed by full spectrum absorbing clouds covering 60% of the sky or at specific wavelengths absorbed by greenhouse gases abundantly present in the lowest atmosphere.
Re-radiation by the bottom of a cloud is directed upward and downward. The upward-directed half meets an opaque cloud environment and
will be absorbed. The downwelling half is warming and not cooling the atmosphere and the surface below. Instead of cooling, this half of re-radiation is doing the opposite. Re-radiation by water vapor and carbon dioxide is only at specific wavelengths, missing the wavelengths that are able to reach space through the ‘open window’. Re-absorption by one of the surrounding water vapor or carbon dioxide molecules is what we can expect. And in the same way as for clouds: upward re-radiation is hardly or not effectively cooling and downward re-radiation is not cooling the surface but keeping it warm. The total delay in cooling must be huge, if not helped by some natural solution.
To overcome the problem of non-cooling in the lower troposphere, it is needed that re-radiation takes place from higher elevations lacking water vapor. A shortcut is needed: convective upward transport. But large-scale convective transport first happens when evaporation is firmly activated (happening at higher surface temperatures) and/or when sensible heat reaches a high level. For convection to take place at relatively low surface temperatures, cooperation with a lot of lightweight H2O molecules is needed. But intrinsic properties of the H2O molecule restrict evaporation at the lowest temperature levels. Consequently, considerable upward convective transport does not take place at low temperature levels but first in the higher range found on our surface. In humid circumstances, convection is huge from 26 degrees Celsius.
Because of the Earth’s high greenhouse effect (which has been high ever since the creation of Water Earth) the level of the Earth’s surface temperatures always has been dependent on the very dynamic and temperature-dependent strength of convection. Without convection, it would not have been possible to get surface temperatures down to the present level. Given Earth’s natural greenhouse atmosphere, surface radiation alone simply cannot do the job and never could. Re-radiation without preceding convective upward transport can’t do the job either. Convection is the bottleneck and because of the intrinsic properties of the H2O molecule, the quantity of convection that is needed to result in present temperatures first takes place at present temperatures. Higher temperatures speed up evaporative-convective-cloud cooling dynamically, lower temperatures diminish evaporative-convective-cloud surface cooling dynamically. Intrinsic properties of the H2O molecule determine final surface temperatures (for every specific state of the Earth’s surface and position of the planet) and its intrinsic properties never change(d).
Greenhouse gases don’t change the intrinsic properties of the H2O molecule either. And the quantity of greenhouse gases doesn’t play a role: without evaporative-convective-cloud cooling, surface temperatures of Water Earth always would have been too high for present life. Too high, simply by the natural system which is evaporating the main greenhouse gas water vapor in quantities determined by the intrinsic properties of the H2O molecule. The stimulating effect on convective cooling by the extra water vapor is high, but the (logarithmic) warming effect of the same rise in water vapor is only very low. High surface cooling by water vapor neutralizes (low) initial surface warming by water vapor.
To prevent overheating by the natural greenhouse effect, the solution came from the natural system itself: evaporative-convective-cloud cooling, setting and stabilizing surface temperatures at a life-friendly temperature level. Whether extra greenhouse gases have an initial warming effect (and they have) is not of any importance: the surface-cooling convective system immediately reacts to the slight rise in surface temperatures by cooling strongly and in doing so, prevents a final rise in temperatures. Temperatures above present temperatures highly activate evaporative-convective-cloud cooling, temperatures below present temperatures deactivate.
What brings some variation (1-2 degrees) over centuries is natural variation by a dynamic (and unpredictable) oceanic-atmospheric climate system, variations happening in super-imposed cycles of different cause and magnitude and altogether behaving up and down. All on the timescale(s) of the Earth.
P.S. I suppose Donald L. Klipstein and Donald L. Kipstein are one and the same person.
I repeat, eliminating all non-radiative cooling of the surface only removes 97 of the 493 W/m^2 that is leaving the surface. And, for an extreme calculation, warming the surface enough to have this replaced by radiation outgo even with 60.5% of that extra radiation being returned to the surface by clouds and greenhouse gases means increasing the surface temperature to have 100/39.5 times 97 W/m^2 radiation increase, from 493 to 739 W/m^2. Even that would only increase surface temperature in Kelvin by 10.65% of what it is now, from 289.09 K / 15.9 C to 319.99 K / 46.73 C.
As for delay of outgoing heat because most of it is other than the 5.556% of radiation from the surface that escapes to space non-stop: Some of the remainder escapes with only absorptions and reradiations by greenhouse gas molecules along the way, which mostly happens in a matter of milliseconds. But if you want a thermal time constant of outward radiational cooling of the atmosphere (including the at least 99% of its molecules that are not of greenhouse gases): A square meter column of Earth’s atmosphere has mass of about 10,100 kg/m^2 as averaged over Earth’s surface, with average figure at sea level being 10,323 kg/m^2. Using 10,323 and the R Universal Gas Law Constant of 8.31446 J/mole-K and atmospheric average molar mass rounded down to .0289 kg/mole and using the diatomic molecule figure for specific heat at constant pressure being 7/2 of R, a square meter column of Earth’s atmosphere, I figure it takes 10.4 megajoules per square meter to change the temperature of Earth’s atmosphere by 1 degree C/K. Divide this by the 217 W/m^2 outgoing longwave radiation from the atmosphere and multiply this by the average temperature of Earth’s atmosphere as weighted by density (which I estimate as 260 K, even though 249 K radiates 217 W/m^2), I figure thermal time constant as 12.46 million seconds, which is slightly less than 40% of a year. Because heat flows in the atmosphere are changing slowly over multiple decades, storage time of 40% of a year while things are changing over multiple decades means that delay as calculatable by storage time has negligible effect.
BTW, I don’t have a spell checker running on how I type my surname.
Donald L. Klipstein: “Even that would only increase surface temperature in Kelvin by 10.65% of what it is now, from 289.09 K / 15.9 C to 319.99 K / 46.73 C.”
WR: Final temperatures on Real Earth are set at about 288K (15°C), 31.73 degrees lower than calculated above for ‘radiation cooling only’. The same conclusion remains: ‘something else’ than radiation is setting surface temperatures on Earth. And the only option for that ‘something else’ is the H2O-related cooling system.
The question is, whether (1) the strength of an independently operating (by its intrinsic properties activated and de-activated) evaporative-convective-cloud-cooling system sets surface temperatures independently from the strength of the greenhouse effect, or (2) the strength of the greenhouse effect still can play a role while radiation-only is not able to bring back surface temperature to actual level but the independently operating H2O-related surface temperature system does (by cooling being strongly activated and de-activated respectively above and below actual average surface temperature)*.
*Note that another important role is played by the intrinsic property of the H2O molecule to freeze at 0 degrees Celsius (freshwater) or minus 1.8 degrees Celsius for seawater, adding to H2O-control of surface temperatures. This intrinsic property puts a cap on temperatures for ocean water below sea ice, keeping ocean temperatures between a yearly 30°C and -1.8°C.
I agree with you that if the only effect of water is its vapor being a greenhouse gas, Earth would be warmer than it is now. But I disagree with your calculation methodology & your claim that Earth’s surface temperature would be anywhere near 202.3 C. I showed my work indicating less than 47 C with oversimplifications in the direction of higher temperature. Meanwhile, ability of water to freeze or melt does not change the numbers of the Figure 1 energy budget of the surface and of the atmosphere (except by surface albedo positive feedback if surface temperature is changed, which neither of us is considering so far), while both of us are using the numbers in Figure 1 in our calculations. There is still the matter that change of greenhouse gases is changing these numbers slowly over decades, while you argued (including on basis of a delay that I showed a calculation of) that because most of the subset of surface radiation that makes it out to space is other than the 5.556% of surface radiation that goes there nonstop without even being re-emitted towards space after absorption by a greenhouse gas molecule, the surface has no radiational cooling other than that 5.556%.
Donald L. Klipstein: ” I agree with you that if the only effect of water is its vapor being a greenhouse gas, Earth would be warmer than it is now. But I disagree with your calculation methodology & your claim that Earth’s surface temperature would be anywhere near 202.3 C.”
WR: The calculation is for the theoretical planet described (about the standard theoretical planet used to compare planets) and the calculation is by the S-B calculator. The claim is that the Greenhouse effect is huge and that on Real Earth ‘something else’ than surface radiation has to bring down surface temperatures to the low level of 15 degrees Celsius. Because of the greenhouse effect caused by the low efficiency of surface radiation in reaching space, surface radiation can’t bring down surface temperatures to the actual level. That ‘something else’ that sets the actual level is H2O-related surface cooling, there simply is no other option. As indicated, the intrinsic properties of the H2O molecule activate and de-activate surface cooling by H2O in a way that 15 degrees Celsius for the present state results.
Donald L. Klipstein: “Meanwhile, ability of water to freeze or melt does not change the numbers of the Figure 1 energy budget of the surface and of the atmosphere (except by surface albedo positive feedback if surface temperature is changed, which neither of us is considering so far), while both of us are using the numbers in Figure 1 in our calculations.”
WR: You are correct. Freeze or melt does not change the numbers of the energy budget used. Freezing or melting depend on the specific intrinsic property of the H2O molecule to do so at the temperature prescribed. But the numbers for minimum and maximum temperatures of the oceans also show the dominance of H2O in setting surface temperatures at actual level, far from the ‘radiation only cooling’ for the surface of the theoretical planet. I added the numbers to further show the overall dominance of the H2O-molecule over surface temperatures.
Donald L. Klipstein: “There is still the matter that change of greenhouse gases is changing these numbers slowly over decades, (…)”
WR: That greenhouse gases are changing numbers over decades is an assumption. We know numbers are changing over decades, but they always did: the history of weather and weather events and of climate change over geological periods shows. Even in periods with nearly stable CO2, global climates have been changing enormously, as the enormous jump in temperatures from the Last Glacial Maximum to our warm Holocene shows. Science requires that ‘all other options have to be refuted’. My option is that warmer subsurface inflows into the Arctic of warmer than usual Atlantic waters have resulted in ice melt over decades, changing the quantity of water vapor in the air above, resulting in changing weather patterns. A near endless flow of low-pressure systems was drawn to the Arctic, taking warm and humid air with them, resulting in high turbulence also in the upper layers of the ocean (by the storms), enhancing surface mixing (warming, because the lower water in the Arctic is warmer), resulting in more ice melt etc. How the change in weather patterns affected the weather in Western Europe is well described here: https://rmets.onlinelibrary.wiley.com/doi/epdf/10.1002/joc.7763
As all happens in cycles, this multidecadal pattern will reverse at some moment. Because all happens against the background of the recovery from the cold Little Ice Age, the net effect for the near future cannot be predicted: a multitude of natural factors are playing a role. But the influence of the warming of the Arctic by the subsurface inflow of warmer than usual Atlantic Water has been huge. We know ‘Global Warming’ is not global, as it should be in case a well-mixed greenhouse gas would cause a change in temperatures. The Northern Hemisphere warms much more than the Southern Hemisphere that even partly cools (close to the Antarctic). Within the Northern Hemisphere, it is especially the Northern Atlantic and the Arctic that warms, influencing weather changes in Europe. See the study above.
Donald L. Klipstein: “while you argued (…) the surface has no radiational cooling other than that 5.556%.”
WR: I agree that I left out cooling by re-radiation, but that is different from ‘[arguing]… the surface has no radiational cooling other than that 5.556%’. Because all surface radiation (100%) has to reach space to get the lowest temperatures, warming is the result when they don’t. Shown is the result for 5.556% which gives the maximum temperatures this greenhouse atmosphere would result in. This is an unequivocal measure for the strength of the greenhouse effect, a standardized one.
Bottom line is that when re-radiation would be able to set surface temperatures at present low level, the surface of the Earth would not show 80 W/m2 (or 50%) cooling by evaporation nor dynamic convective cooling around actual temperatures. H2O sets surface temperatures, nothing else.
What you are describing is an insulator with a given conductivity and a gradient across it. The gradient is not just due to CO2 but several things.
Regarding “Re-radiation by the bottom of a cloud is directed upward and downward. The upward-directed half meets an opaque cloud environment and will be absorbed.”: Some of that is convected to cloud tops, which radiate to space heat other than the 5.556% you mention. Also, some of the clouds that absorb outgoing radiation are thin, which means some of the surface radiation they absorb becomes heat that gets radiated upward with no need for convection. Also, some of the outgoing radiation from the surface other than the 5.556% you mention has no clouds in its way and is absorbed by greenhouse gases and that gets reradiated, often but not always with more than one absorption and reradiation, but some of this eventually gets radiated upward. For every 333 watts of radiation to the surface from greenhouse gases and clouds combined, there is 217 watts of radiation by these into space.
Donald L. Klipstein: “Some of that is convected to cloud tops, which radiate to space (…)”
WR: Agree. Even within clouds, convection plays its role. Cloud tops are very good emitters: they emit full spectrum and above clouds the water vapor content of the atmosphere is low enough to get a much more efficient radiative cooling.
The more I learn about Earth and its climate, the less important CO2 becomes.
All but the greening effect, which has a reciprocal benefit.
Your body is cooled mostly by evaporation of sweat– not by radiation.
It’s basically the same for the planet.
Roest nails it.
Thanks to water vapor our temperature system is far more stable than admitted by the consensus,
far MORE?
I FORGET WHAT ARE THE UNITS FOR STABILITY?
WHAT CLAIMS OF STABILITY DOES THE CONENSUS MAKE? ipCC PAGE
NUMBER WILL SUFFICE
HOW MUCH MORE STABLE DO YOU THINK IT IS?
HOW DID YOU MEASURE THIS
LET ME GIVE YOU A CLUE
Lyapunov exponents
CALCULATE IT FOR THE CLIMATE TIME SERIES.
THAT WOUL BE Data you dont trust
good luck
Steven M. Mosher: “What claims of stability does the consensus make?
WR: The consensus accepts the instability as expressed in scenarios 1-5 of Climate Report AR6 IPCC 2021:
SSP1-1.9: 1.5°C by 2050
SSP1-2.6: 1.8°C by 2100
SSP2-4.5: 2.7°C by 2100
SSP3-7.0: 3.6°C by 2100
SSP5-8.5: 4.4°C by 2100
Source
Apparently the Second Law of Thermodynamics does not apply to climate science.
Apparently, the fact that absorption and re-emission of IR and higher is quantum mechanical and has nothing to do with statistical mechanics (i.e. the SB law) is irrelevant.
Apparently, the empirical evidence that shows that taking CO2 concentrations up to 100% has virtually no measurable effect on temperature is also irrelevant.
Neither are convection, albedo, adiabatic heating, the magnetosphere, and a host of other factors considered by other researchers too numerous to mention.