One Upside of More CO2: Beautiful Upper Atmospheric Clouds

Reposted from Dr. Roy Spencer’s Blog

January 1st, 2020 by Roy W. Spencer, Ph. D.

Polar Stratospheric Cloud display (smartphone photo posted by Reddit user Breuuan on Dec. 31, 2019.)

Increasing carbon dioxide in the atmosphere will continue to cause upper atmospheric cooling in the 2020s, which will lead to some of the most beautiful cloud displays ever witnessed by human eyes.

Along with the warming in the lower atmosphere that more CO2 is theoretically expected to produce, the upper atmosphere is supposed to cool even more strongly. For example, in our satellite observations since 1979, we have observed about 3-4 times as much cooling in the middle stratosphere as warming in the troposphere over the last four decades. This cooling is expected to exist even higher up, into the upper mesosphere and beyond, which is at the edge of outer space and where meteors burn up. The current record solar minimum conditions are probably also contributing to this cooling.

Polar Stratospheric Clouds and Noctilucent Clouds are Increasing

As 2019 came to a close, reports of some of the most vivid opalescent displays of wintertime polar stratospheric clouds (PSCs) in memory have been coming in from Northern Europe. These clouds require very cold temperatures in the stratosphere (-80 deg. C or colder). They show up shortly after sunset or before sunrise when the sun is still shining at that high altitude (15-25 km), while the usual weather-related clouds in the troposphere are no longer illuminated by the sun.

Wintertime polar stratospheric clouds in Sweden, Dec 30, 2019 (by Patricia Cowern Israelsson).

In the summertime in the polar regions, electric-blue noctilucent clouds (NLCs) are sometimes seen in the upper mesosphere (80-85 km) where temperatures plunge to the coldest anywhere on Earth, -100 deg. C. Like PSCs, they are seen after sunset or before sunrise, but due to their great altitude occur when the sun is well below the horizon and some brighter stars are beginning to shine. These clouds exist at literally the edge of space, above 99.999% of the mass of the atmosphere, and are believed to be seeded by meteoric dust.

Summertime noctilucent clouds (Nando Harmsen,

These clouds have a rippled appearance, and time lapse photography has revealed an amazing variety of undulations, like waves from multiple pebbles thrown in a pond interacting. The following 4K time lapse video shows cloud behavior unlike any you have seen before, and is well worth the 2 minutes it takes to watch (go full-screen):

2017 NOCTILUCENT CLOUD CHASING SEASON TEASER – 4K (UHD) from Night Lights Films on Vimeo.

Last year (2019) NLCs were observed well outside the polar regions for the first time in recorded history, as far south as southern California and Nevada. This is due to some combination of colder temperatures and higher water vapor amounts (methane is converted to water vapor at these altitudes, and increasing atmospheric methane could be causing higher humidity up there).

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January 2, 2020 6:32 am

I can remember seeing clouds similar to the first picture in Sheffield, Uk way back in the early ’90s.

Shame I didn’t have a camera with me.

January 2, 2020 6:40 am

Wonderful. I can’t go there to see for myself, so thanks for making me feel closer.

Nick Schroeder
January 2, 2020 7:11 am

0.04 of the atmosphere has some kind of significant effect.
Seems too good to be true.

GHGs “trapping” “extra” energy created by a theoretical “what if” calculation violates the thermodynamic conservation of energy law.
Because of the contiguous participating atmospheric molecules black body LWIR upwelling from the earth’s surface is not possible.
The earth gets warmer without the atmosphere not colder.
The greenhouse effect, carbon dioxide’s warming and man-caused climate change do not exist.
It is that simple.
Debunking CAGW does not require a couple thousand words, dozens of pages, esoteric graphs and charts and a blur of pretentious handwavium.

Reply to  Nick Schroeder
January 2, 2020 7:48 am

“The earth gets warmer without the atmosphere not colder.”

Space outside of our atmosphere is 3 kelvins (absolute zero is is 0.0 kelvin the coldest anything can get) and our atmosphere is 283.33 kelvins (10.17 C. or 50.3 F). Without an atmosphere earth would be at near 3.0 kelvin just above absolute zero.

Reply to  JOHN CHISM
January 2, 2020 9:54 am

Without the atmosphere, warming and cooling is a surface phenomenon. At night there would be dramatic surface cooling and dramatic warming in daytime.
What the atmosphere does is retain thermal energy throughout its depth.

Reply to  JOHN CHISM
January 2, 2020 10:03 am

Only matter can have a temperature, space being the absence of matter has no temperature.

An earth with no atmosphere would still be heated by energy from the sun.

The temperature of the moon varies between 127 and -173 degrees Celsius.

A airless earth would not experience quite such drastic spread as the day is shorter, so less time to warm during the day and cool at night. Still it would have a much larger temperature range than we have with air.

There is also heating from the earth’s core to consider.

Nick Schroeder
Reply to  BillP
January 2, 2020 3:15 pm


UCLA Diviner data: Lit side, 390K, dark side 95K.

The Diviner site notes that the moon is how it is because it has not an earthy atmosphere.

The obvious corollary is that w/o the atmosphere the earth would be much like the moon: hot^3 lit side, cold^3 dark side.

Take away the atmosphere, lose the .3 albedo, gain at least 20% more kJ/h – and hotter is the only option.

Zero RGHE theory, Zero GHG warming, Zero CAGW.

Reply to  Nick Schroeder
January 3, 2020 4:27 am

The temperature you quote are approximately the same as I did, just K instead of C. So we are in agreement there.

I thought it was obvious that I was talking about the moon because it is an airless body the same distance from the sun as us. Hence it is a first approximation to an airless earth. So we are in agreement there.

As I pointed out the earth revolves much faster, so temperature rage would be smaller, but the median should be about the same. That is about -20C (253K).

The other difference between the earth and the moon is the atmosphere. So that must be responsible for any difference in median temperature. So we are in agreement there.

The difference in median temperature is that the earth is about 30C (30K) warmer.

You can debate which parts of the atmosphere cause this, but the atmosphere as a whole unquestionably warms the earth.

Nick Schroeder
Reply to  Nick Schroeder
January 3, 2020 7:17 am


“You can debate which parts of the atmosphere cause this, but the atmosphere as a whole unquestionably warms the earth.”

Yes, but how & why? It’s the blanket/house analogy NOT the greenhouse analogy. See where Pierrhumbert 2011 agrees.

As noted elsewhere it’s the thermal resistance: Q = U A dT same as the insulated walls of a house. U = conduction + convection + advection (wind) + latent (evap & cond) + rad. Emisivity = rad / (conduction + convection + advection (wind) + latent (evap & cond) + rad) The surface is warmer because of U increasing dT there is no change in Q. The atmosphere is just a second year HVAC problem.

To move current through an electrical resistance requires a voltage difference.
To move fluid through a hydraulic resistance requires a pressure difference.
To move energy (heat) through a thermal resistance requires a temperature difference and GHGs and LWIR plays a minor, if any, role.
Physics is physics.

I have more details posted on my LinkedIn site.

K is the scale, C is the unit. 30K is -243K not 30 C.

Reply to  Nick Schroeder
January 3, 2020 11:44 am

Nick Schroeder
“The obvious corollary is that w/o the atmosphere the earth would be much like the moon: hot^3 lit side, cold^3 dark side.”
The reason Earth has a atmosphere is because of the processes taking place deep beneath our feet.

“On Earth, flowing of liquid metal in the outer core of the planet generates electric currents. The rotation of Earth on its axis causes these electric currents to form a magnetic field which extends around the planet.”

Nick Schroeder
Reply to  JOHN CHISM
January 2, 2020 2:08 pm


Space – the Hotter Frontier

One of the heated issues underlying greenhouse theory is whether space is hot or cold.

Greenhouse theory says that without an atmosphere the earth would be exposed to a near zero outer space and become a frozen ice ball at -430 F, 17 K.

Geoengineering techniques that increase the albedo, the ISS’s ammonia refrigerant air conditioners, an air conditioner in the manned maneuvering unit, space suits including thermal underwear with chilled water tubing, UCLA Diviner lunar data and Kramm’s models (Univ of AK) all provide substantial evidence that outer space is relatively hot.

But outer space is neither hot nor cold.

By definition and application temperature is a relative measurement of the molecular kinetic energy in a substance, i.e. solid, liquid, gas. No molecules (vacuum), no temperature. No kinetic energy (absolute zero), no temperature. In the void & vacuum of outer space the terms temperature, hot, cold are meaningless, like dividing by zero, undefined. Same reason there is no sound in space – no molecules.

However, any substance capable of molecular kinetic energy (ISS, space walker, satellite, moon, earth) placed in the path of the spherical expanding solar photon gas at the earth’s average orbital distance will be heated per the S-B equation to an equilibrium temperature of: 1,368 W/m^2 = 394 K, 121 C, 250 F.

Like a blanket held up between a camper and campfire the atmosphere reduces the amount of solar energy heating the terrestrial system and cools the earth compared to no atmosphere.
This intuitively obvious as well as calculated and measured scientific reality refutes the greenhouse theory.

Reply to  JOHN CHISM
January 3, 2020 6:21 am

you forget the geothermal heat inside the earth’s crust.

Bill Rocks
Reply to  Leo Smith
January 3, 2020 7:32 am


Geothermal heat flow averages approximately 0.08 W/m^2. A rounding error compared to the sun?

Reply to  Bill Rocks
January 3, 2020 11:56 am

Bill Rocks

It’s what goes on under our feet that creates the resistance so life as we know it can exist here on Earth.
“On Earth, flowing of liquid metal in the outer core of the planet generates electric currents. The rotation of Earth on its axis causes these electric currents to form a magnetic field which extends around the planet.

The magnetic field is extremely important to sustaining life on Earth. Without it, we would be exposed to high amounts of radiation from the Sun and our atmosphere would be free to leak into space.”

Gary Pearse
Reply to  Nick Schroeder
January 2, 2020 9:39 am

Nick S: CO2 doesn’t ‘trap’; a molecule momentarily absorb an LWIR photon rising up from the earth’s surface, vibrates, and then re-emits a photon in any direction. If the greenhouse gas wasn’t there, the photon would pass, at the speed of light, through the ‘transparent’ GHG atmosphere to outer space. Holding the photon up briefly and scattering in any direction slows the direct exit of heat causing a bit of warming. It has nothing to do with the specific heat of the gases or whatever your vague idea is.

Not knowing this is a disservice to sceptics

Reply to  Gary Pearse
January 2, 2020 12:28 pm

Thanks for that explanation, while I claim no expertise in this matter, as an engineer it makes the most sense.
One of the things that annoy me, it seems that it is often explained as though it is a 1 step process which of course it is not, it is continuous since the photon is re emitted. It seems as though slowing the heat loss is consistent with claims that overnight cooling is less but max daytime temperature may not be higher. Of course UHI is a significant factor in higher overnight cool downs.
I have no idea what governs.
Please feel free to correct any misunderstanding I may have.

Reply to  Gary Pearse
January 2, 2020 1:17 pm

Big changes to come in 2020

Nick Schroeder
Reply to  Gary Pearse
January 2, 2020 2:14 pm

Gary, even if this molecular process were real (imho it’s dubious) 0.04% of the atmosphere doing this would make approximately zero difference.

And since the atmosphere cools not warms the earth your handwavium explanation of how that non-existent warming works is superfluous.

The surface is warmer than ToA per Q = U A dT same as the insulated walls of a house.

Reply to  Gary Pearse
January 2, 2020 2:53 pm

The delay times involved in that IR photon being absorbed and readmitted, perhaps many times, is not the main means of greenhouse warming.
The major warming occurs because the final IR photon emitted to space from a CO2 molecule high in the cold atmosphere occurs at a much slower rate than a similar IR photon emitted from the surface. The difference is due to emission temperature and the Stephan-Boltzmann relationship. Slower IR emission to space means atmosphere must warm to compensate.

Nick Schroeder
Reply to  donb
January 2, 2020 3:55 pm


Wave your hands any harder you’ll levitate.

Reply to  Gary Pearse
January 2, 2020 6:57 pm

Gary Pearse
“Holding the photon up briefly and scattering in any direction slows the direct exit of heat causing a bit of warming.”
Gary , How many photons are added to the natural processes from man made wireless communications and remote sensing, IMHO that’s were the added energy is coming from and disrupting weather and climate.

Reply to  Gary Pearse
January 2, 2020 7:07 pm

CThe issue is that CO2 absorbs a minor amount of IR, 8%? Converts it to kinetic energy which is then distributed over the entire atmosphere. This is done in the 15 micron band primarily. Once used this way to heat the atmosphere, there is no remaining energy inside the CO2 molecule to re-emit.

This is the basic premise of the quantum mechanics that govern absorption and emission to a substance. Einstein determined the Einstein A and B co-efficients which govern the fact that these are quantum energy amounts and are not variable energy amounts that go into and out of the molecules.

This is a procedure that has been discussed years ago on the Air Vent, on RealClimate, by Pierrehumbert, on Rabbett Run by Joshua Halprin, , and in conversations between William Happer and Physics students and professors. The Earth has a quenching atmosphere where the CO2 absorbs energy and turns it to atmospheric heat in the lower atmosphere. NO energy is left to re-emit. (of any consequence).

Throughout the total atmosphere there is re-excitation of about 1.4% of the CO2 molecules.
(each time one is re-excited it removes heat from the atmosphere as a whole. The energy to do this has to come from somewhere.) The Law of Conservation of Energy has to be conserved.

These re-excited 1.4% of CO2 molecules have to be quenched again and again as the rapid atmospheric collisions do not allow them to emit either.

Finally the CO2 molecules at the TOA , Stratosphere, Thermosphere etc. become excited. They are far enough apart that they are not quenched by collision. THEY can emit. Some emit towards Earth and they are reabsorbed. More emit outwards and cool the Earth as a whole.

It is sufficient to say that a CO2 molecule’s time to re-emission is about a billion times longer than the time to collision in the atmosphere. This prevents this incorrect belief in emission from a CO2 molecule from occurring in the lower atmosphere. It happens but maybe once in a billion absorptions. Other mechanisms to spread the IR energy via emissions have been proposed but not in the 15 micron band.

Nick Schroeder
Reply to  Butch123
January 2, 2020 8:07 pm

Your explanation only matters if the atmosphere warms the earth – which it does not do.

Kevin kilty
January 2, 2020 7:34 am

If one can see these clouds, then they scatter sunlight, don’t they? Thus, they must have an impact on solar irradiance at the surface. How large is it? I suspect it is at least as large as a doubling of CO2.

Farmer Ch E retired
Reply to  Kevin kilty
January 2, 2020 9:13 am

My question also. Do these extra layers of clouds reflect more heat or trap more heat?

Farmer Ch E retired
Reply to  Farmer Ch E retired
January 2, 2020 9:51 am

Rather do these clouds have a net heating or cooling effect.

Nick Schroeder
Reply to  Farmer Ch E retired
January 3, 2020 9:35 am

Heat is not “trapped.”

Reply to  Kevin kilty
January 2, 2020 9:21 am

As far as I can tell, these clouds are an infrequent phenomenon. link For that reason, I wouldn’t expect them to have a big influence on the climate.

Almost everything about these clouds is a bit mysterious.

Ice does not form at the low pressures of the mesopause unless the temperature is below -123°C. These low temperatures only occur during a few weeks around the summer solstice and the surprising combination of summer and low temperatures is a consequence of global circulation in the middle atmosphere.

So, the mesopause gets colder in the summer. OK then …

January 2, 2020 7:38 am

“Beautiful Upper Atmospheric Clouds”

Ah, I can see it now:

Polar bears sitting back drinking a Coke and seeing clouds that looks like their Grandma!

Reply to  JohnWho
January 2, 2020 8:08 am

Polar bears sitting back drinking a Coke and seeing clouds that looks like their Grandma!

You sure they’re not snorting coke?

Reply to  Redge
January 2, 2020 9:09 am

Yes, ’cause I’ve seen them on TV watching the Aurora Borealis and clearly drinking Coca-Colas.

Although, now that you mention it, there was a lot of white powder around them.

January 2, 2020 8:30 am

A UC Boulder study concluded that less than 10% of the cooling of the upper atmosphere was caused by CO2. The rest was caused by lower solar activity. I’ve cited that paper previously on this site several years ago. I can dig it up again if others are interested

Reply to  Manny
January 2, 2020 9:21 am

“I can dig it up again if others are interested.”

Please do so.

Joe Campbell
Reply to  Manny
January 2, 2020 10:21 am

Manny: I’d like the pointer to the paper you mentioned above. Thanks…

Reply to  Manny
January 2, 2020 11:44 am

Here is an article on the study. You can find it by searching on the title of the article. Please note that this article is about the thermosphere and not the stratosphere.

CU Boulder Today
Study Shows Shrinking Atmospheric Layer Linked to Low Levels of Solar Radiatio
Published: Aug. 26, 2010

“…The results showed the thermosphere cooling in 2008 by 41 kelvins (about 74 degrees Fahrenheit) compared to 1996, with just 2 K attributable to the carbon dioxide increase. The results also showed the thermosphere’s density decreasing by 31 percent with just 3 percent attributable to carbon dioxide. The results closely approximated the 30 percent reduction in density indicated by measurements of satellite drag….”

January 2, 2020 8:36 am

“Increasing carbon dioxide in the atmosphere will continue to cause upper atmospheric cooling in the 2020s, which will lead to some of the most beautiful cloud displays ever witnessed by human eyes.”

But if carbon dioxide is a dense gas then how is it supposed to reach the upper atmosphere to cause this cooling?

Joel Snider
Reply to  Marv
January 2, 2020 9:26 am

The idea is that more C02 will result in more water vapor – clouds.

Reply to  Marv
January 2, 2020 1:14 pm

The theory is that the CO2 in the lower atmosphere reduces the amount of heat getting from the surface to the upper atmosphere.

Which is correct as far as it goes, but ignores various feedback effect.

January 2, 2020 9:49 am

So, how can consensus science turn this beautiful display into a threat? Maybe some animals cant sleep at night and die from stress? Or insects get lost when navigating by the lights, Or birds lose sexual interest in their mates when their feathers look dull and gray compared to the night sky and the birds die out?
I am sute they will think up something resembling science and swedish state media will teport it as a fact.

Joel Snider
Reply to  björn
January 2, 2020 11:06 am

Easy – just get a picture of Greta, yelling threateningly, with her image spread like a panoramic image over the horizon – like the old Darth Vader images, looming in the background on the original Star Wars poster.

Play the Imperial March in the background.

January 2, 2020 10:39 am

I love stuff like this. Under the right conditions, some clouds can produce dragons and other mythical critters. Even better if it happens at sunrise or sunset. I’ve got photos of cirrus clouds so high up that they’re shedding ice particles and look like jellyfish. Must be colder than cold up there.

Thanks for the video!!!

R.S. Brown
January 2, 2020 11:06 am

Currently on

comment image

michael hart
January 2, 2020 2:03 pm

I’m just pleased to read somebody discussing direct affects of CO2 upon cloud formation high up in the troposphere.

Perhaps in a few more decades we’ll see climatists discussing how to model it in a way that simulates reality in a useful manner.

January 2, 2020 2:27 pm

When viewing clouds I always look for a mid-1950 Ferrari.

January 2, 2020 6:35 pm

Putting an IR photon into a CO2 molecule and having the molecule re-emit a photon will cause abso lutely NO warming of the atmosphere. You can ONLY use energy one time. If the energy in a photon is re-emitted it cannot have been used for heating.
What happens is that almost all of the absorbed photons are converted to kinetic energy or thermalized in the atmospheric molecules when they collide with the energized CO2 molecules.

Then the energy is gone, It cannot be re-emitted because it has been expended as thermal energy accelerating the particles in the atmosphere as a whole.

TOA spectra prove this. If there was re-emission the notch in the 15 micron band of CO2 absorption would not exist. The energy would find its way to TOA eventually.
What you are being asked to believe is that the Law of Conservation of Energy does not exist and that CO2 can magically both warm the air and re-emit photons in the lower troposphere.

The lower troposphere is a quenching atmosphere that grabs the energy of the CO2 molecule and immediately converts it to atmospheric movement. Once this is done the CO2 molecule cannot re-emit.

Robert of Texas
January 2, 2020 8:25 pm

Whaaaaaat???? Higher CO2 is going to cause warming down lower and cooling up higher? I am racking my brain but cannot come up with the physics behind this. And this sentence:

“methane is converted to water vapor at these altitudes”

is just wrong. You CANNOT convert methane (CH4) into water vapor – no way, now how. You can oxidize it producing CO2 AND H2O (water) – which has to be (very sloppily) what they mean. But you can do that in the lower atmosphere as well. It just takes a little bump of energy.

So back to a cooler high atmosphere. I found this which makes sense:
“New measurements from a NASA satellite show a dramatic cooling in the upper atmosphere that correlates with the declining activity of the current solar cycle.”

Less ultra-violet light from the Sun, less energy to absorb, lower temperatures. OK, got it. But how does an increase in CO2 warming the lower atmosphere COOL the upper atmosphere? The Earth has to remain in energy equilibrium, so are they suggesting that less high energy radiation is reflected by the Earth? Is it due to pressure gradient of an expanding atmosphere? Thinner air would mean less kinetic (direct) heat transfer and a higher radiant emission. It has to be due to atmospheric expansion, I can’t think of anything else that would cause this.


Reply to  Robert of Texas
January 2, 2020 8:38 pm

Additional CO2 has an overall effect of increasing CO2 both at the lower Troposphere and at the Stratosphere.
(CO2 is considered a well mixed gas by most. )

SO, when there is an increase lower, it makes little difference in absorption of the IR emitted from the Earth. It will be absorbed in the same few tens of meters that it has been absorbed.

IR emitted from the surface is going to be about the same amount and it is going to be absorbed and converted to warmth in the lower Troposphere almost immediately. This is a one way process. IR is converted to heat.

At the Stratosphere we also see an increase in CO2 molecules. The outer edges of these molecules expand the volume that CO2 may emit from. Thus a minor increase in emitting molecules to space. Cooling will increase slightly.

January 3, 2020 1:45 am

No-one so far has mentioned aviation. There are a lot of aircraft flying round the world above the tropopause, pumping out water vapour. Does this not increase noctilucent clouds?

January 3, 2020 12:02 pm

Is this the reason for the increase of “Polar Stratospheric Clouds and Noctilucent Clouds are Increasing”

“A number of experiments and observations have figured out that, under the right conditions, radio communications signals in the VLF frequency range can in fact affect the properties of the high-energy radiation environment around the Earth,” said Phil Erickson, assistant director at the MIT Haystack Observatory, Westford, Massachusetts.

VLF signals are transmitted from ground stations at huge powers to communicate with submarines deep in the ocean. While these waves are intended for communications below the surface, they also extend out beyond our atmosphere, shrouding Earth in a VLF bubble. This bubble is even seen by spacecraft high above Earth’s surface, such as NASA’s Van Allen Probes, which study electrons and ions in the near-Earth environment.”

January 3, 2020 12:23 pm

As a chemist/chem. eng. this noctilucent cloud business instantly put me in mind of Liesegang phenomena = periodic patterns of reaction products or precipitation in a diffusion dominated viscous medium. (took me a while to remember the name to go with the visual recognition, though)

Check it our here

Picture Chem comment image

and Clouds comment image

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