Clouds: The Wild Card of Climate Change

There should be very interesting discussions and debates on this topic. I remember Dr. Roy Spencer said that from his initial studies, there is a negative feedback of clouds and water vapor on initial warming by man-made GHGs.

My thought is rather simple in that all clouds have an albedo effect. The pro AGW thought is that the net effect is positive, some clouds warm, some cool, some are neutral, depending I suppose on the relative changes in LWIR and SW which reach the surface. The idea being that the clouds increase the residence time of LWIR in the atmosphere while the vast majority of SWR continues to the surface.
My thought is that not all photons are equall due to their relative residence time in earth’s system, both ocean and amotsphere. So a cloud that blocks 5 W/m’2 of SWR through albedo, but has a 15 W/m’2 warming effect through the GHG effect will warm the atmosphere, but do to the far longer residence time of SWR photons entering the ocean the reduction of those 5 W/m’2 reduced SWR will have a stronger long term effect which is cumlitive depending on the duration of the change in cloud cover, and certainly as Stephen Wilde expresses, their laditude, which as they shift poleward obviously effects an ever greater % of the TSI. Ans so some clouds may indeed cause a short term atmospheic warming, but a longer term ocean cooling.
I definitely do not have the numbers to quantify the effect I am considering, primarily because I do not know the residence time of SWR photons entering the ocean vs the residence time of LWIR in the atmosphere. Any help here is appreciated.

david says:
November 5, 2010 at 4:57 am
“So a cloud that blocks 5 W/m’2 of SWR through albedo”
is hardly a cloud.
Fixed that for ya. Cloud top albedo is on the order of 80%. That means it reflects 80% of the light from the sun straight back out into space. That’s closer to 500 watts per square meter than it is to 5 watts. At night they reflect less than 50% of the upwelling long wave radiation back towards the surface and to make it even more unbalanced clouds tend to form in the morning and early afternoon and dissipate in the late afternoon and early evening.
The only “mystery” is exactly how unbalanced the situation is on a global average basis but there’s no credible doubt that clouds have a large net cooling effect. There’s also no doubt that there are more clouds when it’s warmer and fewer when it is colder. So if there is any additional forcing (more surface heat) from higher CO2 level this results in more clouds which will negate the additional forcing from CO2.
The ONLY significant greenhouse effect from CO2 is that first 100ppm or so raises the average temperature of the earth from below freezing to above freezing which activates the water cycle. Once the water cycle is active it takes over the regulation of surface temperature through negative feedback. The only thing to fear is when CO2 is not enough to keep the surface temperature above freezing. When that happens the water cycle effectively screeches to a halt and the surface gets covered with snow which also reflects 80% of the sun’s light and thus fosters even colder surface temperatures and even more snow in a vicious cycle of falling temperatures.
Evidently the pre-industrial level of 280ppm CO2 isn’t enough to stop the brief interglacial periods from ending as for the past several millions of years the earth is largely covered by glaciers 90% of the time. One can only pray that an anthropogenic driven doubling of CO2 to 560ppm or even a quadrupling to 1100ppm is enough to indefinitely extend the Holocene interglacial. If not then human civilization is in for big trouble. Imagine glaciers two miles thick covering all land surfaces from Washington, D.C. northward and land south of that having harsh winters instead of being above freezing all year round.
Hastening the end of the Holocene interglacial by reducing CO2 emissions is utter insanity.

“The role of clouds is enigmatic because clouds can exert opposing forces: Some types of clouds help cool the Earth and some types of clouds help warm it”
Well that certainly clears up the certain uncertainties!!!
What we don’t know is amazing !!

David Springer is absolutely right.

Anytime a cloud comes between the sun and the earth, there is an immediate and noticeable drop in temperatures, that increases the lower a cloud is. That can only mean that the albedo-enhancing effect dominates the heat trapping effect by quite a large margin, so during the day, clouds are a negative feedback.
When the sun isn’t shining however, clouds do keep things warmer than they would otherwise be, therefore they could be said to have a positive feedback effect at nighttime.
Overall, given the same amount of clouds at night and day, the effect would be negative, because they are reflecting away a lot more energy than they are retaining. I’ve never noticed a rise in temperatures at nighttime when a cloud comes over as much as the drop in temperatures in the daytime.

Whenever I see a straight line I know that I am looking at an artifact. When I see a feedback loop I know that I am looking at a computer programme. If nature allowed continuous looped feedbacks, the universe would have burned up billions of years before we were born.

From “Prof.” J. Collins:
“I’ve looked at clouds from both sides now,
From up and down, and still somehow,
It’s cloud illusions I recall,
I really don’t know clouds, at all. ”
A “golden-oldie” still good today!

Dave Springer says:
November 5, 2010 at 5:57 am
“There’s also no doubt that there are more clouds when it’s warmer and fewer when it is colder.”
I need to qualify that, Dave.
It’s certainly true locally (after a short period of adjustment when perversely the opposite applies as the system plays catch up with the temperature change) and perhaps regionally, but globally ? There’s the rub.
The evidence from the Earthshine project is that cloud quantities decreased during the recent warming spell and are now increasing with the cessation of warming and perhaps beginning of cooling. Likewise albedo.
http://bbso.njit.edu/Research/EarthShine/literature/Palle_etal_2006_EOS.pdf
So how could that be ? Strange how so many observations are turning out to have the reverse sign from standard expectations isn’t it ?
I would explain it by reference to the shifting of the jet streams and thus the associated cloud bands latitudinally.
At the same time as the albedo and cloudiness trends reversed in the late 90s I noted that the jets were starting to shift back equatorwards.
So my bet is that in shifting equatorward the cloud bands were stretched along a greater global circumference, increasing the length of the air mass boundaries and allowing more air mass mixing to produce more clouds.
Additionally the equatorward shift makes the clouds more reflective since they block higher intensity insolation.
That is what primarily causes global albedo changes and thereby changes the amount of solar shortwave able to penetrate the oceans.

Any ‘proper’ cloud reflects most of the sunlight back out into space. As this radiation never actually gets to the surface clouds by definition cool the Earth. Do we have decent records of Earth albedo from projects such as Earthshine and the many satellites we have orbiting us?

massive ice growth in arctic LOL
see DMI

Hey, wasn’t that J. Mitchell?

“Photons have practically no residence time anywhere. They travel with the speed of light, whether they are “short wave” (UV or optical) or “long wave”.”
The above is a standard diversionary tactic when inconvenient questions are raised. It limits the discussion to radiative physics which is not sufficient on its own to explain what goes on within the Earth system.
Those inconvenient questions may mention photons but in reality as in this case the question relates to the heat generated when those photons interact with elements of the Earth system.
Any honest responder to the question would understand that and respond appropriately. This responder did not so I invite others to make their own judgement.
David’s question was sensible and understandable despite the slight error of terminology. I have done my best to answer it properly in another thread.

The two things I don’t get about clouds:
1) How can we have more water vapor and fewer clouds?
2) If clouds are such a big deal for the climate, why don’t we address them through irrigation and forest management policy rather than CO2 controls?

The ocean of air we live at the bottom of is filled with moisture, and the interchange between clouds of water, clouds of ice, haze and humidity and has apparently been nearly ignored by our AGW promotion industry. How strange.

This type of amazing discovery has been discussed on WUWT for the several years that I’ve been coming here. I believe I know what is going oTn. The “concensus” is making these late discoveries, taking credit for them and gradually dovetailing into the arguments that sceptics of CAGW have been making since the beginning. And now a word about the cloud feedback issue to settle this nonsense:
The net effect of clouds – all kinds- is to reduce the warming effect of the sun through albedo. Check it out – on a hot day, when a cloud passes over, you can feel a significant cooling. Let us semi-quantify the effect instead of vaguely talking about IR going back up and being partly reflected back down. If the cloud reflects, say 50% of the sun’s rays coming in, then the sun’s IR reaching the earth’s surface is reduced. Now some of this reduced IR bounces back up to the base of the cloud where a fair percentage (I said semi-quant!) passes through and a fraction of the initial sun’s IR is reflected back which is partly re-reflected and part of it goes through the cloud again…. If you lost half of the incoming IR, these bits bouncing around are not going to make an increased IR heating under the cloud.
Now if I am wrong about this, I would like a semiquant explanation of the phenomenon instead of …sometimes up and sometimes down.

“How can we have more water vapor and fewer clouds?”
When the jet streams shift poleward as they do when the troposphere warms the jet streams and their cloud bands extend around a reduced global circumference as they move towards the poles. Thus a shorter length for the air mass boundaries, less air mass mixing and less clouds generated.
So a warmer troposphere but less clouds and lower albedo exactly as per observations
http://bbso.njit.edu/Research/EarthShine/literature/Palle_etal_2006_EOS.pdf
Now in reverse as it happens 🙂

The uncertainty caused by clouds is already factored into the IPCC estimates of of probable range of temperature raise.
From http://www.nsf.gov/news/special_reports/clouds/question.jsp
CLOUD CLOUT AND DOUBT
The IPCC reported in 2007 that it projects the Earth’s average temperature to be about 1.8 to 4 degrees Celsius higher by the end of the century than it was in 1900–a rapid rate of increase compared to observed rates of increase in the Earth’s recent history. Scientists could probably narrow down the Earth’s projected temperature range further if they better understood the relationships between clouds and climate as well as other factors, such as the amount of greenhouse gases that will be pumped into the atmosphere by 2100.
Most scientists doubt that the net cooling effect of clouds will ever be large enough to completely offset ongoing warming. But many scientists say that if warming were to increase the number or kind of cooling clouds or decrease the presence of warming clouds, the current net cooling effect of clouds on the Earth’s climate would probably increase, and thereby moderate, or offset, ongoing warming.
If warming were to continue, the net cooling effect of clouds would increase and, in a negative feedback loop, perpetuate the moderating force on ongoing warming provided by clouds. The result: The Earth’s end-of-the-century temperature may be pulled down toward the lower end of its predicted range.
But, if on the other hand, warming were to increase the number or kind of warming clouds or decrease the presence of cooling clouds, scientists say the current net cooling effect of clouds on the Earth’s climate would probably decrease; and an important moderating force on ongoing warming would thereby diminish. The result: The Earth’s end-of-the-century temperature may be pushed up towards the upper end of its predicted range.
This resulting rise in temperature would, in a positive feedback loop, tend to promote the formation of even more warming clouds or further reduce the presence of cooling clouds. Either way, temperatures would rise even higher. This temperature increase would tend to further increase the presence of warming clouds or decrease the presence of cooling clouds, and thereby perpetuate the warming cycle.

DISGUSTING.
They roll out stuff that Atmospheric Physicists have know about for more than thirty years – and announce it like it was some kind of revelation.
I am DISGUSTED by what is clearly just “gravy train science”.
This is like Hollywood or the music industry re-issues of “25th Anniversary Editions” of classic albums of movies!
Academic Science is now purely a BUSINESS. A damned gravy train. If Colorado State were Hollywood or the music industry, legitimately out to make a profit, then this kind of thing woudl be acceptable.
Since when did it become acceptable for our Universities to simply regurgitate well know facts trumped up as something new. Did they “remaster” the orginial text books? Have they enhanced the image quality with new rendering of the details in high definition?
This is most definitely NOT science.
It reminds me of the outright plagarism in the recent tree ring textbook where there was no reference to the original text and graphics.
Of course, the climb down for certain “Climate Scientists” is going to be challenging – now that everyone knows of the completely false representation of “Climate Change” by the media, politicians and gravy train seeking academics! I guess they can hardly admit that the uncertainty about the impact of clouds is as old as the hills and as old as climate science itself!
Now if only all these gravy train seeking liars can divert the Billions in research funding and industry sponsorship of their various departments…..towards the CLOUDS!
CLOUDS is the new BLACK.
DISGUSTING

A bit OT, but will there be a series of “one year on” articles in the lead up to 17th November?

Nuke says:
November 5, 2010 at 6:48 am

So we don’t know how the oceans affect the climate (at least the models don’t include the oceans) and we don’t know how clouds really affect the climate either, whether warming causes more clouds or whether less clouds causes the warming (which is cause and which is effect), but we know what the climate is going to be in 20, 30, 50 or 100 years? Really?

May I make just a few minor adjustments?
…but we know what the climate models are going to say in 20, 30, 50 or 100 years?
We should.

Jason says:
November 5, 2010 at 8:21 am
Surely volcanoes are the wild card?
======================
I sometimes wonder if the deck of cards used in the climate game contains anything other than Jokers.

Clouds: Zillions of tons of WATER floating against the HOLY LAW OF GRAVITATION and we don’t even surprise ourselves!, why do they float over? why do they defy gravity and why do they, after loosing its charges fall down as RAIN, HAIL OR SNOW and we do not know why?. Have we been condemned to not knowing or rather to belief in the abstruse explanation rendered by the voodoo science’s Shamans?
http://www.scribd.com/doc/40514613/Unified-Field-Explained-8

I’ve engaged the Real Climate folks about this in the past, & Gavin managed to scrub all of my posts! Coward. No tolerance for honest scientific discussion.
It appears that the impacts of cloud formation on climate are very much unknown (i.e. “there is no consensus”). Even measuring “cloud cover” is daunting with today’s instruments!
This presentation by Dr. Joel Norris of the Scripps Institution of Oceanography is excellent, it is highly detailed in terms of the physics & math (he presented this colloquium to a stadium full of Fermilab PhD physicists, including Nobel-laureate Leon Lederman).
Dr. Norris discusses height of clouds, albedo, positive vs. negative forcing etc.
Please watch, and download his powerpoint slides.
http://vmsstreamer1.fnal.gov/VMS_Site_03/Lectures/Colloquium/100512Norris/index.htm

If the cloud cover is included in many AGW models, they deal with them on a daily basis, that is, they do not consider the persistence of clouds. When a cloud is formed during the day, it may condense and disperse at night, but equally it may persist for several days.
One day’s cloud production, reducing the temperature in that first day in a region, may go on to affect perhaps several subsequent days elsewhere. Is this not an extended inter-day and geographically widespread negative feedback effect?

Jimbo said:
“The issue is one of causation. They have not accounted for cloud changes causing temperature changes.”
http://www.drroyspencer.com/2010/04/the-great-global-warming-blunder-how-mother-nature-fooled-the-world%e2%80%99s-top-climate-scientists/”
Nor have they considered that the cloud quantity changes might themselves be caused by reverse sign ozone reactions in the mesosphere (cooling when the sun is active and vice versa) altering the atmospheric heights, shifting the jets and their cloud bands and thereby altering albedo.

NSF? Really? Maybe Roy Spencer hasn’t just been pounding his head against the wall in vain on this subject then.

“In order to help clear the air on clouds…”
Bad pun.

All this talk of clouds not being understood. What is to not understand ?
All clouds of any type, at any height anywhere on earth, at any time, ALWAYS reduce the amount of primary solar radiation energy that reaches the surface. The same is true of just water vapor itself; even in the absence of any clouds.
More WATER in any form in the atmosphere ALWAYS reduces the amount of solar energy that gets absorbed by the earth; no matter what.
When climatists start talking about positive cloud feedback; they immediately bring up last night’s balmy weather and the high clouds; And they claim that the higher the clouds are the more they warm the ground, and vice versa. So Noctilucent clouds are really are doing a job on us; keeping us warm.
The weather was balmy last night because it was even warmer during the day, and humid too, so there was plenty of water vapor in the air. And when the sun went down and that warm moist air rose; it eventually reached the dew point and formed clouds; yes nucleation conditions, will affect just how much and how quickly clouds form; and as it continues to cool at night you will get more of those clouds up high. Those high clouds at night are the result of the balmy weather conditions later in the daytime; they are not the cause of those conditions at the surface.
And the question is not:- do clouds at night cool or warm the planet ? The question is:- Over some meaningful climate time scale; does an increased amount of cloud cover make earth warmer or does it make it colder? And bear in mind, that MORE clouds ALWAYS means LESS solar energy being absorbed by the earth.
The sunlight lost to cloud reflectance is a no-brainer; a total loss to space. But the H2O vapor, and liquid, and solid H2O clouds ALL absorb additional solar radiation energy; primarily in the 0.75 to 4.0 micron wavelength range where about 45% of total sun energy resides. And the water absorption spectrum looks like it could be removing up to as much as half of that. I wouldn’t say more than 20% of sunlight.
That solar energy that is absorbed by the H2O in the atmosphere, warms the atmosphere. In that sense it is quite indistinguishable from the effect of LWIR radiation emitted from the ground. Regardless of GHG species, the net result is to warm the atmosphere. That warmed atmosphere then radiates isotropically, so an average about half can return to the surface, and the other half is lost to space. And don’t forget, whether going up or going down; there will be a cascade of multiple re-absorptions, and reheatings, and re-radiations from that warmed atmosphere; but only half of it should reach the surface.
And when the atmopsheric downward LWIR thermal radiation reahces the surface IT DOES NOT simply add to the original solar spectrum energy. They are 20 times apart in spectral wavelength, and they DO NOT have comparable effects on the surface. The solar energy propagates tens to hundreds of metres deep (in the ocean), the LWIR propagates tens of microns into the ocean surface; where it promotes prompt evaporation. So how much of that energy is actually re-absorbed in the ocean ?
In any case the original solar part of it, is a net loss to the planet, since without the water all of it would reach the surface; but with the water, only half will (roughly). < That's half of the energy that got absorbed by the atmosphere; not half of total solar.
The sun always illuminates half of the earth surface; actually slightly more than half due to atmospheric refraction which adds at least one degree at each end of the day. When the lower limb of the sun touches the horizon off Waikiki beach in the evening, the sun is already completely below the geometrical horizon. Well half is good enough. The other (slightly less than half) has no sunlight.
Anybody who believes that a cloud blocks more outgoing energy during the shortened night, than it blocks incoming sunlight during the lengthened day; just clearly doesn't understand simple geometry; nor the laws of geometrical optics.
The FEEDBACK question is very simple. Does a 1% increase in mean global cloud coverage from say 50% to 51%; ( lets say we just average that over a full one year trip around the sun; to get all the nuances), cause the earth to gain energy, or to lose energy ?
To believe it could cause the earth to gain energy; knowing that it absolutely MUST LOSE solar energy; is just plain idiotic.
I don't need any supercomputers to tell me that just can't happen.
There's a handful of seminal papers that between them point to what is wrong with climate science.
1/ SCIENCE July-7, 2007 Frank Wentz (RSS, Santa Rosa CA) et al. "How much More Rain will Global Warming Bring ?"
Their MEASURED results say that a one deg C increase in mean global surface Temperature causes a 7% increase, in total global evaporation, total atmospheric water content, and total global precipitation. Arguably the latter must be accompanied by about a 7% increase in precipitable clouds. This is a simply huge negative feedback cooling effect. (Don't for get the astonomical amount of latent heat that is conveyed to the upper atmosphere along with that water vapor, during the evaporation, and the dumping of that heat to the upper atmosphere during the precipitation portion.)
2/ Geophysical Research Letters (I think) Jan 2001. John Christy et al. A report on results from oceanic buoys of SIMULTANEOUS oceanic near surface water temperatures, and near surface atmospheric temperatures. Over about 20 years of data gathering, the warming of the one metre depth water Temperatures was about 40% greater than the warming of the + 3 metre high atmospheric Temperatures. BUT most importantly; they found that the water Temperatures, and the air Temperatures ARE NOT CORRELATED ! Why the hell would anyone expect them to be, with ocean currents of a few knots, and wind speeds in multi tens of knots.
SO WHAT. Well for one thing, it means the vast amount of global temperatures data taken from the 70% of the earth's surface prior to about 1980 by reading water temperatures; is all bogus as a measure of lower tropospheric air temepratures to integrate with land station readings.
And since they aren't correlated; the historic lower air temperatures are not recoverable. So most of that HADCrut global temeprature data, is pure garbage before about 1980.
Also, you can go back to the exact same GPS global co-ordinates, you were at six months ago; and find yourself in totally different water from that you measured previously.
So (a), I don't believe their historic measured temperatures data; and (b) I don't believe their GCM cloud models; other than that; those chaps are doing one hell of a job !
I presume that if anybody had peer reviewed research published that refutes either Wentz et al, or Christy et al, we would all sure have heard about it.

Olen says:
November 5, 2010 at 11:45 am
Are clouds the new CO2.?
That’s what the Global Warmers/Climate Changers/Climate disrupters/Gaia believers want us to believe, but common sense, tells everybody that it is the contrary.
The fact is that we are living in times which will be recorded in future history as a Dark Age. We don’t know it because we have taught to believe in Names and Tags: “That is called WATER, baby, water,…you drink water”, nobody told us we can make water, for example, from protons and ozone, nobody ever told us, except traditional knowledge, that everything can originate from two opposite charges, and that reality and the knowledge of it, it is not an inextricable entanglement of invented by “post normal scientists” Ghosts: like antimatter, black sucking holes, mysterious strings and infinite
dimensions, etc. something than can only be grasped BY THE HOLY “THEM”, the Shamans of this Era of Darkness. However we can free ourselves from such a servitude by not paying any time more respect to such a witchcraft; we are now at the Apocalypse, at the time of revelation (apocalypse in Greek) :
http://www.scribd.com/doc/40514613/Unified-Field-Explained-8

Anthony Watts has written in some detail about the “Urban Heat Island” effect. In fact bricks and concrete are just two types of mud stone (sedimentary). In aired regions throughout the globe large rocks (hundreds of meters) are exposed to blistering sun. Most of these rocks are both darker and denser than cement or brick. There is anecdotal evidence that these rocks act as super heat capacitors. I know of no rigorous study one way or the other. Rocks absorb visible light and radiate infra red. We assume that given no other forcings but the sun and the rocks ability to radiate that the rock would reach thermal equilibrium at 0 degrees Fahrenheit. That would require the rock to completely radiate all the excess heat it picked up at night. My guess is that different rocks absorb and radiate differently. Remember they would be absorbing different radiation than they would be radiating. While the rocks have been there for millions of years this balance would be significantly affected by even a slight change in cloud cover. I’m not a scientist; but, I don’t see how you can separate the effect of clouds from the thermal characteristics of rocks. Furthermore is all of the warming (33 C) due to GHG? Could large rocks coming to equilibrium account for some of that “lost heat” I keep hearing about? I just don’t know.
Has anybody considered a simple experiment? Get slabs of various rocks. Expose them to sunlight. Measure the ambient temperature, the rocks temperature and the incident sun light (perpendicular to the face of the rock slab). After a year see if the rocks average temperature was the same as the ambient average.

Clouds, pfft, stuff without firm substance, bwahahaha.
The true wild card is the ice and all that other white stuff on the ground. Brrrrr.
T’ink ’bout it.
What do we get with global warming, but less cold therefore snow and ice.
Now what do we get with less snow and ice but more greenery stuff that produce oxygen while sucking up all over abundance of them truly horribly evil carbon dioxide molecules.
But who’d be so dumb to model nature as pretty awesome at being able to self balance itself like a proper balanced system that is never at balance but always is trying to balance itself so to speak.

feet2thefire says:
November 5, 2010 at 12:18 pm
“I have simply never seen any image of the Earth that shows 70% overall cloud coverage, nor even over 50%.”
70% is a direct quote from NASA:
http://www.nasa.gov/centers/goddard/earthandsun/icesat_light.html

Everyone knows what a cloud looks like, but scientists need to know what percentage of clouds cover the Earth everyday, in order to make their computer climate models and weather forecast computer models work better. ICESat has provided the most accurate figure to date, and tells us that 70 percent of the world is cloud covered. Previous estimates ranged from 50 to 75 percent.
Image to right: ICESat Studies the World’s Clouds: ICESat has helped NASA scientists get an accurate picture of the world’s cloud cover. ICESat measurements show that 70% of the world is cloud covered ICESat’s assessment is arguably the most accurate to date. Pictured here are Cumulus clouds. Click on image to enlarge. Credit: NOAA/Historic NWS Collection

nofate says:
November 5, 2010 at 11:18 am

Henrik Svensmark: “The bottom line seems to be that instead of thinking of clouds as something being a result of the climate, it actually (is?…garbled word) sort of upside down. It is that the climate is the result of changes in the clouds.”

Keep in mind the earth without greenhouse gases would have an average temperature of 5F. If there were no ocean and with current concentration of CO2 the average temperature would be 145F. The water cycle (when active, i.e. a liquid global ocean with average temperature above freezing) caps how warm it can get by working as a heat engine to pump heat from the surface into the atmosphere and drive a heat exchanger that removes excess heat from the topics and radiates it out at the poles. On top of that is cloud reflectivity which can reflect up to 80% of the incoming energy from the sun directly back out into space and which cover some 70% of the surface on average. The water cycle (liquid and vapor anyhow) has a negative feedback. Surface heat drives evaporation which forms clouds which shade the surface and reduce evaporation which reduces cloud cover.
Snow and ice are the things to fear because snow has a positive feedback – snow cover reflects up to 80% of the sun’s energy thus cooling the surface and making conditions favorable for the snow cover to continue growing in extent and longevity eventually reaching a tipping point (last few million years anyhow) which ends the short (15,000yr) interglacial periods and plunges the earth back into a long (120,000yr) glacial epic.
The key role that CO2 plays is helping to warm the earth from below freezing to above freezing. Below freezing the water cycle is pretty much stopped. Cold air doesn’t hold much water vapor and nothing is evaporating when the surface is frozen over so CO2 is the only thing keeping it from reaching an average temperature of 5F and staying there. However, once CO2 gets it above freezing then the water cycle comes alive and through inescapable negative feedback caps the maximum average temperature at a comfortable level when distributed more evenly through the year and from low to high latitudes. The highest temperature the earth ever attained was barely 10F higher than today and the higher northern and southern latitudes were where most of the warming occured. So unless you’re an ice hugger that values permafrost for some dumb reason then whatever global warming we can possibly get is a good thing as far as abundance of plants and animals is concerned. It may be slightly disruptive to human activities but even then there will be far more winners than losers.

These are just a layman’s observations that relate to clouds, but given the fact that the science is obviously not settled, a layman’s observations and thoughts are as good as those of someone who has a string of Phd’s: Where I live, Hobart Tasmania, Australia, (43 degrees south, roughly), the coldest-ever maximum temperature, (4 degrees C), occurred after a minimum of about – 1.5. The sky had been covered by cirrostratus for a few days. This uniform sheet reduced the sun to a pale disc by day and did absolutely nothing to keep Hobart warm by night. Decks of high clouds do not prevent frost here.
Hobart, like San Francisco, is often kept cool by a stubborn layer of marine stratocumulus on summer mornings when the anticyclone produces a southeast breeze. You don’t have to have a computer model to work out that high clouds keep the surface temperature down and do nothing to keep the nights warm, while hill-hugging clouds keep the weather cool by day, and retain some heat during the night.
These low clouds moderate the overnight temperature, but delay the warming of the ground until around midday or sometimes mid afternoon so their presence in the morning keeps the maximun temperature down because the ground has less time to soak up the sun.
A warming climate world-wide, will mean more evaporation but the atmosphere can’t hold H2O vapour when it cools. Man might contribute to GW, which I doubt, but there is no doubt that man can’t stop the earth from spinning and from revolving around the sun, so increased evaporation in a warming world inevitably leads to the world being cooled by clouds which form when air is cooled during the daily and seasonal cycles. Therefore GW is self limiting! It is scandalous that so much money is wasted on a phantom problem. Meanwhile Australian politicians have done nothing to bolster the defences of places like the Gold Coast. The 1954 Gold Coast cyclone destroyed a sleepy little village. A similar cyclone today would wash the sand away from the foundations of skyscrapers, inundate the canal estates and destroy highways and communications. But we don’t have to worry, because we can prevent cyclones by controlling our emissions!!!!!!! Green pundits like Tim Flannery have been made to look like fools by the recent floods. Melbourne is going to use massive amounts of coal-fired electricity to remove NaCl from seawater, because rainfall was supposed to be a thing of the past. I wonder what the people in Gippsland think about that while they scrape silt off their walls and carpets. A dam on the offending river could be built at a fraction of the cost of the desal plant and relieve Gippslanders of their dreary floods. Ask any farmer over eighty years of age. The recent drought in SE Oz was not unprecedented; it was just part of what mother nature does in the “sunburned country the land of drought and flooding rains.” When opera singe Dame Nellie Melba returned to her home state early last century she was horrified by the news that Victorians were actually starving to death because of drought and famine. So what’s unprecendented about the recent drought?
I used to vote Labor, but I can’t do that anymore. A vote for Labor in Australia is a vote for Green madness. I consider myself a true green. Green politicians have the lost their way; they are looking at the wrong side of the carbon cycle. They need to ask themselves where molecular oxygen comes from. It is apparent in Australia that the Greens in parliaments are interested in all sorts of non-green things, (eg euthanasia, gay marriage), and they are quite happy to promote so-called eco-friendly cars, and solar panels as long as the minerals needed for their electronic components are not mined at Uluru or Fraser Island. What the world needs is plenty of forests and plenty of phytoplankton in clean oceans. I just read Andrew Bolt’s blog. Apparently the Taiwanese people have lower electricity bills than the Australian people, even after paying for Australian coal and paying for its shipment. I just read an article on WUWT, “Carbon Shoe Comparisons”and it put my blood pressure up. I get really mad every time I think about the hypocrisy of politicians. I would like to see the greens get out of politics and rediscover their true purpose in the scheme of things, which is to agitate to preserve forests and keep the world clean.

Well how well do you believe those Temperatures and values.
Let’s start with a fairly non controversial mean value for the TSI at 1366 W/m^2. I assume that’s an average value over the earth’s elliptic orbit, and say averaged over a sunspot cycle.
At that irradiance level; the equlibrium Temperature for an insulating Black Body (cavity) is 393.96… Kelvin; call it 394 or 120.8 deg C
Now the earth is not an open black body cavity facing the sun. Next approximation would be a perfectly conducting black body, so it is isothermal. So we expect it to be radiating at an average of 341.5 W/m^2 from 4 times the area that is receiving solar energy. The equilibrium Temperature at 341.5 W/m^2 is 278.575 K or 5.425 deg C
Well the earth is not one of those either.
Next version seems to be the above isothermal earth with an albedo of 0.3
That has the effect of dropping the TSI down to 239.5 W/m^2 everywhere on an isothermal planet. and now we get an equilibrium Temperature of 254.81 K; the often cited 255 Kelvins; sans greenhouse effect.
Problem is that a 255 K body with no greenhouse gases also has no clouds; so no way is it going to have an albedo of 0.3
70% of the surface is ocean, and that tends to be concentrated in the tropics, so somewhat greater than 70% of the incoming solar radiation, will see an albedo that is more like 0.03; 3% instead of 30%.
Well I could go on twiddling and you would get bored as fast as I would.
But if you get just a little bit more real, and actually let the planet rotate, as it is believed to do, then suddenly the earth’s surface sees more like that 1000 -1366 range of insolation values, albeit over only part of a 24 hour cycle; but no way is that going to permit, a cloudless water vapor less atmosphere.
During the sunlit noonday tropical period, the earth is going to be shooting for that 394 K (121 C) equilibrium Temperature; and that most certainly is going to result in lots of evaporation, and lots of H2O vapor, and H2O cloud , so I can’t see how the need for the CO2 kindling wood is proven.
With NO GHG other than H2O, the earth will self start just fine. Actually, even in a CO2 less situation you will have an ozone band right at that 9.6 micron wavelength where the earth wants to head to as it warms up.
The requirement for CO2 to jump start this planet from a frozen ice ball is pure speculation; and a big part of the problem is this silly insistence that the earth is an isothermal body in stable thermal equlibrium.
It isn’t; it rotates; and that’s why I ROFLMAO every time I see Trenberth’s caricature of what HE thinks the earth energy budget is.
The TSI is 1366 W/m^2 part time, not 341.5 full time.

I think that it should be pointed out that no heating is required for clouds to form.
Water will evaporate or sublimate if the water vapor pressure is low enough according to Henry’s law. Air with water vapor in it is lighter than air that is dry, therefore the dry air will displace the humid air upward. This results in more dry air passing over the surface of the water, damp soil or ice and more evaporation or sublimation as air movement increases the effect. Therefore, water on its own can cause convective currents and the hydrologic cycle. Once the air currents are large enough then the Coriolis force will start altering the vector of the winds and colder air from the poleward side will move under warmer air from the equatorward side and weather fronts can start forming a larger version of the small scale with cold dry air moving under the warm humid air the air will be lifted till the lapse rate results in 100 percent humidity at the dew point and cloud will form. As the water condenses out it releases heat either warming the atmosphere or being radiated – slightly more than 50% will of the radiated IR will be upward to space. As the convection continues the water carried upward will turn to ice again releasing latent heat. If the winds cross hills then there will be orographic uplift and it may rain on the windward side of the hills.
No GHG are needed only water.
Even in ice ages the tropics will be above freezing with similar insolation as now. So there will be clouds forming in the tropics but their albedo could keep the Earth cold.
The idea that ‘clouds are only a feedback’ is incorrect. Clouds will form if there is water on the surface. Water vapor is light and is its own GHG and will self generate more water vapor. All that CO2 can do is move the hydrologic cycle faster to a climatological equilibrium point where cloud albedo cancels out any warming due to the CO2.

The mechanism of clouds and what controls their formation are so complex that it is impossible to quantify the effect they have on climate. They are a major part of the heat pump which maintains our climate in it’s benign state, and which allows the biosphere to thrive. They are driven by the same deterministic chaos which produces the regular quasi-cyclic oscillations we observe, and the sudden ‘black swan’ events of temperate zone glaciation – the ice ages.
It is not just the type, height, colour, density, temperature e.t.c. which is important, but when and where they form and their persistence. Climatologists really don’t know clouds, at all.

“All that CO2 can do is move the hydrologic cycle faster to a climatological equilibrium point where cloud albedo cancels out any warming due to the CO2.”
Exactly Tenuc, you’ve got it.
And the change in speed of the hydrological cycle manifests itself by a miniscule unmeasurable shift in the air circulation systems that are regularly moved latitudinally by 1ooo miles or more over a few centuries by entirely natural forces.

@ sky says:
November 5, 2010 at 4:48 pm
——
Sky, thanks for taking the time to watch! What I took away from Dr. Norris’s talk was the following;
a) the effects of clouds on climate change have not been adequately addressed by the climate change community in AR4 etc.
b) clouds of different altitudes and depth can have quite different effects upon forcing
c) technology to different cloud cover from snow-covered ground is much less than perfect, so actual cloud coverage is very much guesswork.
His was nowhere close to the barn-burner that Dr. David Archer gave to Fermilab with his “The Big Thaw” lecture!
I’m professional enough to engage in the most vociferous climate change proponent or absolute climate change skeptic. In fact, I quite enjoy the fight! I would have enjoyed having an open debate with Dr. Archer, but the crowd would have torn me to bits…
I’m quite impressed with Dr. Spencer’s “global thermostat” concept, and believe this has great merit for further exploration!
http://wattsupwiththat.com/2010/08/28/congratulations-finally-to-spencer-and-braswell-on-getting-their-new-paper-published/

CO2 as ‘kindling’ for the water cycle.
I like that. A very helpful metaphor, thanks.

@Stephen Wilde
George Smith came up with kindling to describe CO2’s hypothetical primary role of activating the water cycle. The hypothesis is mine but not the metaphor.
The sun doesn’t provide enough energy to raise the surface equilibrium temperature above freezing. If we only had an atmosphere but no greenhouse gases and a liquid ocean the earth would be the same average temperature as the moon (5F) albeit with less radical day/night temperature swings. Albedo would be about the same at around 15%. Fortunately the earth is large enough so that gravity is sufficient to hold an atmosphere. The most critical role of the atmosphere is it gives us 14.7 psi surface pressure which allows liquid water to exist on the surface over a broad range of temperatures. But a liquid ocean does not in and of itself help to warm the earth above freezing. It drastically lowers the day/night temperature swing but without a greenhouse gas it would be a frozen ocean and even colder than the moon because frozen water has a very high albedo. Now we get to where CO2 is critical. The earth does get enough energy from the sun to keep CO2 gaseous at all times so its action as greenhouse gas is never diminished by freezing it out of the atmosphere.. Because its insulating effect requires exponentially more of it to get a linear increase in effect it’s only the first 100ppm or so that is critically important to surface temperature. That is sufficient to raise the average surface temperature above freezing. Once we get above freezing we get a liquid ocean and a water cycle. Water vapor is a far more powerful greenhouse gas which, unlike CO2, has many wide infrared absorption bands and on average it exists at hundreds of times the concentration of CO2. Once the water cycle is activated it essentially makes CO2 into a bit player and takes over as the primary greenhouse agent. The neat thing is that the water cycle has a negative feedback called clouds. As the surface temperature rises from water vapor acting as a greenhouse gas its material properties (lighter than air) causes it to rise and then due to gas laws (expanding gases get cooler) it gets cool enough to condense into a cloud some small number of kilometers above the surface. The cloud then reflects most of the sunlight away from the surface back into space which greatly reduces the energy available for evaporation at the surface which reduces the cloud cover and lets in more energy. So as long as the water cycle is active we get a self-regulating surface temperature that is uneffected by further increases in CO2. The only game changer is then a tipping point (we’re close to that tipping point now) where snow and ice, which has a positive feedback, can freeze enough water out of the atmosphere to start runaway cooling. But there’s another very long term feedback there as well. As the land and ocean freezes over and green plants are drastically reduced the carbon cycle screeches to a halt. At that point there’s little left to remove CO2 added to the atmosphere from vocanic emissions so over the course of thousands and millions of years atmospheric CO2 doubles several times until there’s enough of it acting as a greenhouse gas to overcome the runaway cooling and re-activate the water cycle. Green plants then recover with a vengeance feasting on the excess CO2 quickly turn the earth back into a liquid water world again. The only thing we have to fear is runaway cooling – there’s no such thing as runaway warming.

Thanks Dave, an interesting perspective.
A couple of thoughts though:
i) I think that from the very beginning the water on Earth was in liquid or vapour form because it started to accumulate on the surface when the Earth was young enough for the necessary energy to be geothermal. Therefore I’m not sure there was ever a point at which the water cycle ever needed to be activated from a frozen start.
ii) Once the water cycle exists then as you say it dominates any similar effect from GHGs and I would argue that the water itself including the oceans should be regarded as part of Earth’s atmosphere for the purpose of solar energy retention. Thus in comparison to water those GHGs have never been of any great significance. It is not the GHGs in the air that keep the troposphere warm. it is all that water in the oceans and in the water cycle.
iii) Even if the entire surface freezes over as per the so called speculation about a snowball Earth it is only the top of the oceans that freezes and the Earth is still young enough for volcanic activity to break through and start a water cycle based global melt process so even then I don’t see the GHGs themselves to be necessary. Once sunlight gets in through a volcanically damaged or discoloured ice surface an unstoppable process would begin would it not ?
iv) If we had an atmosphere with no GHGs other than water vapour from the oceans I don’t see that the temperature of the troposphere would be much different ?

“What I can’t figure is a practical artificial way of warming the planet should it start getting too cold.”
All our proposed nuclear energy generating plants from now onward should be placed in a ring along the equator and the warm water from them allowed to flow freely into the oceans. That should minimise the equatorward drift of the jet streams when the sun becomes less active for long periods of time or the astronomic cycles return to conditions favouring reduced solar energy reaching Earth. One could even build plants with the exclusive function of heating up the equatorial seas. Before long we should become much more efficient at avoiding radiation leakages but anyway there is evidence that at low levels additional radiation stimulates the immune systems and evolutionary efficiency of biological organisms.
We could prevent dangerous global cooling and improve the efficiency of the entire biosphere from the same technology and if the globe warms then we can convert the plants into giant water cooling devices instead.
A win win scenario from all angles 🙂

The lunar declinational total portended angle, is driven from the tilt of the poles magnetic fields of the sun, resulting in pulses in magnetic field’s flux of polarity N/S on a 27.32 day cycle. The lunar declinational angle movement is the part of the atmospheric tidal component that causes the positions of the jet streams to be close or far from the Equator.
IF the astrological effects of the long term patterns of Ice age periods, is driven by the actual movement of the tilt of axis of the magnetic poles of the sun, to where when it decreases, the polarity shifts in the solar wind weaken. Thus less driven declinational movement = total included angle reduced = less atmospheric tidal effect mixing equatorial ITCZ warmth into the mid-lattitudes.
Then IF the alignment of the magnetic poles of the sun continued to decrease to where they were almost vertical at some point, the gradual declinational electromagnetic drive component would by then affect a much smaller included declinational angle for the moon….Hardly moving any massive surges of warmth off of the equator = onset of long term Ice age, until the return of increased strength and critical orientation of the galactic magnetic fields that allow a re-tilt of the solar magnetic poles, to the axis of rotation and we come out of the ice age.
This is the basic premise of action in shifting the spin of atoms and watching them rebound in MRI Magnetic Resonance Imaging. We have it down on an atomic level to where it is used daily thousands of times to save lives. Why could the Galaxy not use the same methods by an external magnetic field surge maintained for the duration of the Ice covered state of the glacial stages?
Thus the quick recovery with the magnetic flip, with the return of the pulses in solar wind polarity shifts once again driving the declinational angle of the moon to greater extremes.

Dave Springer says:
November 7, 2010 at 7:37 am
@phlogiston
Yes, the testimony of the geologic column is irrefutable. The much higher CO2 level in most of the past is what kept the earth green from pole to pole for tens or hundreds of millions of years at a stretch uninterrupted by ice ages.
Based on the palaeo timelines of CO2 and global temperature:
http://biocab.org/Geological_Timescale.jpg
I cant quite accept that over the last half billion years (the history of multicellular life), that CO2 and temperature are at all correlated. Both temperature and CO2 are now lower than in the Cambrian – but that is as much as you can say. Looking at the temperature line – it appears to seek two stable levels, about 12C and 22C globally. 22C appears to be the more stable, with a dip toward 12C regularly every 150 million years (Marinoan ice age 600 Mya, Saharan-Andean ice age 450 Mya, cold dip between Carboniferous and Permian 300 Mya, cold dip between Jurassic and Cretaceous 150 Mya, present cold dip and glacial period now). Of course the fly in the ointment is the prolonged fall in temperature during the tertiary epoch. But a bi-stable pattern is none the less discernable. (It has been suggested that the 150 My spaced cold spells are related to galactic rotation and cosmic ray / dust clouds.)
And this biphasic pattern bears no evident relationship to CO2 levels whatsoever. It is quite possible that CO2 plays no role in these temperature fluctuations.
The prediction based on this pattern is that sometime in the next 100 My or so we pop back up to 22C globally – with as you say rainforests at the poles. Regardless of CO2.
Just remember also – according to this paper by Franck et al – CO2 starvation – not overheating – will be the final cause of extinction of life on earth (see fig. 6) – worth remembering before getting too enthusiastic about removing CO2 from the atmosphere.
http://www.biogeosciences.net/3/85/2006/bg-3-85-2006.pdf

Stephen Wilde says:
November 7, 2010 at 9:58 am
re; ice age regular cyclicity
Ice ages aren’t so regular. Interglacial/glacial periods during the most recent ice age are exhibit some regular cyclicity.
re; CO2 levels millions of years ago
I’m not sure but I don’t think the geologic column has the resolution to say whether CO2 leads or lags global temperature. All I know is that when CO2 levels were far higher than today, which is the case during most of the last half billion years, there were stretches of time measuring in the tens and hundreds of millions of years where there were no ice ages. Today we’re in an ice age that has persisted for about 3 million years with brief interglacial respites where the glaciers retreat to high northern latitudes only to return almost like clockwork. The current ice age is about tied for the deepest freeze in the last 500 million years where the other one this deep was over 400 million years ago.
It might be that orbital mechanics are at least partly responsible for the onset of major ice ages with cyclicity in the hundreds of millions of years. This would be the orbital mechanics of our sun in relation to the rest of the galaxy. Our solar system orbits the galactic center at a different rate then the spiral arms such that the solar system transits a spiral arm every couple hundred million years. The density of cosmic rays inside a spiral arm are much greater than outside due to the higher density of stars and hence higher density and proximity to supernovas. If the hypothesis that cosmic rays inhibit or accelerate high altitude cloud formation is correct then the short term cyclicity of the sun’s magnetic field which deflects more or less cosmic rays has a confounding factor which is a very long term cyclic change in the density of the rays it is defecting.
Continental drift must also play some role in very long time frames. Whether one or both poles are occupied or not by a continent would vastly change the mechanics of heat transfer. The poles are like a radiator in a car with ocean currents moving heat from the tropics to the poles. If a continent is blocking the warm current from reaching the pole it’s like your car radiator has a restriction in it which limits the flow which will of course cause the radiator to be cooler and the engine warmer than it otherwise would be. We can see this in the disparity in average temperature between the north and south poles today. The north pole is our most effective radiator today and the less difference in temperature between tropics and poles means the cooling system is working better.
From an engineering (always the way I look at things) viewpoint the melting of arctic ice cap has a negative feedback associated with it. Ice is a good insulator and albedo at the poles means little. A low angles of incidence water is a pretty good reflector of short wave (visible light) and at the poles insolation is minimal to begin with so surface albedo there changes little and on top of that there’s little to change. The interesting thing is that when the ice is gone so is the insulation which is hampering the escape of long wave energy from the surface to space. So as the ice cap extents and duration lessens the radiator performance improves. As the radiator performance improves the source of the heat (the tropical ocean) has heat removed from it faster. This is a negative feedback. Climate boffins believe this is a positive feedback entirely due to albedo change from ice (high albedo) to water (low albedo). But that’s just nonsense when you figure in the amount of insolation potentially changeable by polar albedo change and the inconvenient fact that water has a much higher albedo at low incidence angles.
Another negative feedback in this is the temperature differential between the tropics and the poles in relation to energy available to accomplish the work of moving warm water from the tropics to the poles. A larger temperature differential has a larger potential for producing work. So as the pole gets colder in relation to the tropics the heat pump has a greater potential energy source to move warm water from the tropics to the poles. As more water is moved the temperature gradient decreases and hence less energy available to accomplish the work.
CO2 is insignificant in this interplay as it’s well mixed and doesn’t change phase in the earth’s temperature range. It cannot be a working fluid for a heat pump as your working fluid gets the job done through phase changes. Water is a superb working fluid for heat pumps and heat engines in the phase change from liquid to vapor and vice versa due to it’s extreme latent heat capacity and non-extreme working temperatures.
It seems almost without doubt that orbital mechanics are what is currently tipping the earth in and out of interglacial periods but my question is what happened 3 million years ago that tipped the earth out of a warm period that had lasted for

@phlogiston
Actually I think the great attractor on the cold side is well below the average temperature of the moon if it weren’t for atmospheric CO2. The moon’s average temperature is -23C and its average albedo is near 15%. The earth receives exactly the same amount of insolation but when it gets cold its average albedo rises far higher than the moon due to being covered with ice and snow which of course means the equilibrium surface temperature would be far lower. This is where CO2 greenhouse effect becomes critical. In clear sky with dry air a mere 100ppm or so keeps the surface warmer by a calculated 30C or so which, in most times, is enough to spell the difference between being covered by liquid water and being covered by snow and ice.
Obviously it isn’t always enough as ice ages present well in the geologic column and we’re living in a deepest ice age of the last few hundred million years right now. Complaining about anthropogenic warming in the midst of an ice age seems to me to be something that could only be embraced by those who are grossly uninformed, in a state of denial, or have some vested interest in keeping the FUD (fear, uncertainty, and dread) surrounding the dumbass controversy alive and growing.

George,
At what level of cloud affects would increasing albedo causing a decrease in SWR reaching the surface of the ocean, overwhelm the atmospheric warming of increased LWIR in the atmosphere? In other words can high thin clouds cause a short term warming but a long term cooling due to reduced SWR impacting the oceans?

“”””” david says:
November 8, 2010 at 7:30 pm
George,
At what level of cloud affects would increasing albedo causing a decrease in SWR reaching the surface of the ocean, overwhelm the atmospheric warming of increased LWIR in the atmosphere? In other words can high thin clouds cause a short term warming but a long term cooling due to reduced SWR impacting the oceans? “””””
Well David, I am not sure that I exactly understand your question.
First off, I presume that you DO understand that ANY H2O vapor in the atmosphere WILL block (some) sunlight from reaching the surface (by absorbing it); and maybe 20% of the Total solar spectrum energy is available to be absorbed by H2O vapor. (over the spectral region from about 750 nm to 4.0 microns. Only 1% of solar energy arrives beyond 4.0 microns.
I presume you also understand that ANY increase in H2O vapr in the atmosphere WILL result in more absorption, and even less sunlight reaching the surface; and we are not talking about here today; gone tomorrow; we mean amounts and changes, that persist for climae meaningful times. I’d be happy even with one full trip around the sun.
Then we come to clouds. I presume you understand that ANY cloud will reflect SOME sunlight off the tops back out into space. (albedo); and bear in mind that now we are talking about the WHOLE solar spectrum containing significant energy. Clouds scatter and “reflect”most of the visible range; so a lot more than just the 20% that water vapor could capture. And I assume you understand that ANY increase in clouds will reflect EVEN MORE sunlight back into space. Also I assume you understand that those same clouds will absorb additional sunlight so it doesn’t reach the ground; and that more clouds will absorb even more sunlight.
So any way you want to skin the cat; water in the atmosphere in any and all phases WILL reduce the ground level solar energy; and MORE water, WILL mean LESS solar energy at the ground.
Now the albedo reflections from the clouds are simply lost solar energy; end of story. The atmospheric water absorptions WILL warm THE ATMOSPHERE. The atmospheric warming caused by absorbed SOLAR ENERGY; will result in LWIR emissions; about half of which will reach the surface and MAY warm it; BUT not as much as would have the ORIGINAL solar energy that was intercepted.
NOW THAT is ALL the warming energy there is in the system (neglecting geo-thermal which is miniscule). There is NO OTHER significant source of energy input; it all comes from the sun. (I can just see all the ambulance chaser nit picking lawyers lining up their exceptions).
Now what about the LWIR thermal radiation emitted from the earth surface; and that emitted from the atmosphere. We already explained that a part of the atmospehric LWIR thermal emission is due to the original solar energy absorbed by the water vapor and clouds.
THE REST OF IT CANNOT warm anything. The surface, and the atmosphere, and the clouds are simply swapping that LWIR energy back and forth between themselves; but it is slowly being DISSIPATED to space.
So the most you can say is that the atmospehric absorption of LWIR can and does slow down the cooling of the surface; but it cannot warm the surface. ONLY the SOLAR INPUT can warm the surface; and no matter how you slice it; water in the amosphere can only reduce the amount of solar energy and warming that the earth receives from the sun.
As to the height of the clouds. The sun is a near point source (to some people); specifically it has an angular source diameter of 30 minutes of arc; 1/2 degree. So a cloud casts a shadow, with a 1/2 degree penumbral edge on it. You can see these shadows on the ground from an aeroplane so they are quite real. So a one square km cloud casts a one square km shadow on the ground; and inside that shadow, the surface solar irradiance (W/m^2) is reduced. That same ground shadow zone is also reflecting some sunlight, and emitting some LWIR thermal radiation. Except for a calm water surface, both the reflection and the emission have at least a Lambertian . That is the Radiant intensity varies as Cosine of the angle off normal.
I = Izero.Cos (theta). (Watts per Steradian) We can show that the total energy is simply pi.Izero Watts. Now if we wanted to factor in the area; we would start with the Radiance, in Watts per m^2 per steradian; and we would end up with Watts per m^2 for total Emittance. In this case the Radiance is independent of angle; since the projected area also changes as Cosine(theta).
Now that is the best case. Since the earth surface is quite rough; each surface element radiates in a Lambertian pattern; but the surface orientation is random; so the end result is that the radiation pattern is isotropic.
The point is that whereas the cloud shadow is essentially the same size as the cloud; the emitted LWIR from that area WILL illuminate THE ENTIRE SKY; and out of that entire sky area our cloud is one square km; and it will intercept very little of the LWIR emission from that shadow zone; most of it will escape the cloud. And the higher the cloud is; the less of that surface emission it will intercept.
And what of the LWIR that the cloud DOES intercept. Well some may be reflected again; and some will be absorbed; and subsequently re-emitted; and in both cases; those emissions too, will be at least Lambertian, and more likely isotropic; and the amount of that which returns to our shadow zone is going to be minute in the extreme.
Well actually it will fall off (for the round trip) as 1/H^4 where H is the cloud height; and then there is an obliquity factor of Cosine^8(theta) For 30 degrees off normal, the obliquity factor is about 32%; for 60 degrees off normal it is 3.9%.
Now don’t let the quickness of the hand deceive the eye. We must not forget; that every other spot outside our shadow zone is also emititng LWIR and reflecting sunlight. Each of those elemental areas will have its own cloud height and obliquity factor; so the cloud will receive a lot more LWIR than just from our shadow; BUT on the return trip; when the cloud radiates to the surface; we still have a full 1/H^2, and a cos^4(theta) obliquity, and that cloud radiation will be spread over the entire surface.
But remember that this is just a redistribution of energy which has already been acccounted for in the original solar input.
And no matter what; the clouds; and more clouds will mean less; and even less total energy captured by the earth from the sun; and it WILL cool down. The GHGs just slow the cool down process; but they DO NOT prevent it.

Hell George, let me make the assertion really simple, One SW photon in the ocean is worth two IR photons in the atmosphere. (Only the real numbers need to be quantified). (-:

Don’t know if anyone’s still reading this. Primary benefit of clouds is that they cool the earth by carrying heat up in water vapour, high heat storage capacity, conductivity, without this we’d have desert conditions globally, as we have locally (+20-30degrees C global estimate). CO2 can only join in the cooling, and the rest of cycle, the distribution of water and food for life.
Can’t do the link, but google books Oceanography:an invitation to marine science By Tom Garrison Page 161 for the amazing properites of water.