Researcher: Cloud changes “can result in significant changes to Earth’s surface temperature”

Clouds like a semi-transparent parasol

Climate researcher from the program “Make Our Planet Great Again“ coming from the US to the Goethe University

FRANKFURT. Following the Paris Climate Agreement, Germany and France created the program “Make Our Planet Great Again,“ to promote climate change research. One of 13 researchers selected by an expert jury of the German Academic Exchange Service (DAAD) is coming from the USA to the Goethe University in a few months.

The climate change researcher Dr. Anna Possner is leaving the renowned Carnegie Institution for Science in Stanford and will join the Department for Atmospheric and Environmental Sciences at the Goethe University. Thanks to a one million euro grant, she will start her own research group in Frankfurt. This group will cooperate with the Frankfurt Institute for Advanced Studies (FIAS), where it will also be located.

Anna Possner’s research focuses on layered clouds in the lowest kilometres of the atmosphere, which act as a semi-transparent parasol for Earth’s surface. They reflect a significant portion of incoming sunlight, but only marginally affect Earth’s heat emission. They thus have a cooling effect on Earth’s surface. Any sheet of low-level cloud may span hundreds of kilometres and all together they span around one fifth of Earth’s oceans. Changes in their areal extent or reflective properties can result in significant changes to Earth’s surface temperature.

In some regions of the globe, the mid-latitudes and the Arctic, these clouds consist not only of water drops, but may contain a mixture of ice particles and water drops. The proportion of water drops to ice crystals affects the clouds’ reflective properties. “While we have hypotheses about how the radiative properties may be affected within a single cloud,” Anna Possner explains, “we are limited in our understanding of how the presence of ice crystals impacts the areal coverage and reflective properties on the scale of an entire cloud field.” She will use satellite retrievals and sophisticated numerical models to help answer this question.

Since completing her doctoral dissertation at the ETH Zurich, Anna Possner, who was born in Jena, has studied the impact of particles on the reflective properties of clouds. During this time she focused in particular on low-lying clouds over the oceans, where she quantified and evaluated the impact of ship emissions on clouds. During her postdoc years at the ETH Zurich and the Carnegie Institution for Science in Stanford, she extended her analyses to include mixed-phase clouds.

The German-French program “Make Our Planet Great Again“ seeks to support the creation of solid facts as a basis for political decisions in the fields “climate change”, “earth system research” and “energy transformation”. Of the 13 scientists selected for Germany, seven are in the US, two were most recently working in Great Britain and one each is in Switzerland, Canada, South Korea and Australia. They were selected during a two-stage process out of approximately 300 applications.

Climatologist Dr. Roy Spencer has pointed out his book, The Great Global Warming Blunder:

The most obvious way for warming to be caused naturally is for small, natural fluctuations in the circulation patterns of the atmosphere and ocean to result in a 1% or 2% decrease in global cloud cover. Clouds are the Earth’s sunshade, and if cloud cover changes for any reason, you have global warming — or global cooling.”

And lo and behold, evidence of this has been found:

In a nutshell, with a −1.6%per decade change in cloud cover during 1954–2005, it becomes a climate forcing. While China is not the world, it bears consideration. The Hockey Schtick reports:
New paper finds significant, natural decrease in cloudiness over past 50 years




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Ian W

Clouds reduce the heat from the Sun? Whoever would have thought it?


Ian…………………….DOES THIS MEAN that “They” are going to
START taking this thing seriously ?????????????????????
Nooooooooo!? Really ?


You are correct.

John harmsworth

If she actually finds “negative feedback” she will be defunded and run out of berg on a rail.


Next they’ll ‘find’ rain and snow falls out of the clouds!

Paul S

Too bad Willis didn’t get that million euro grant


Maybe Willis can get half of it as a consulting fee. Split that with Dr. Roy Spencer. A win for everyone!

Clyde Spencer

There is at least anecdotal evidence that the glaciers melting at Glacier National Park are doing so as a result of insolation increases rather that increases in ambient air temperature.


“Researcher: Cloud changes “can result in significant changes to Earth’s surface temperature””
And that is news to who? Anyone that has ever stood outside on a summer day knows that. Just what criteria is used to determine if a research project is worth funding? Discovering that clouds can result in immediate cooling is like doing a study on the results of touching a hot burner. Common sense and experience don’t need to have a scientific study to prove it.


co2 —->” …. Common sense and experience don’t need to have a scientific study to prove it.”
Very true but CAGW modelers need to read it in a paper to understand. That common sense thing perhaps when you’re too invested in academia.

Soronel Haetir

Or outside on a winter night, I see clouds much more as a regulator than a blanket “warmer or cooler”. Clouds make warm conditions cooler and cold conditions warmer. Finding that inflection point would be a useful exercise.

Thomas Homer

Soronel Haetir: “Finding that inflection point would be a useful exercise.”
May I suggest a starting point?comment image

Thomas Homer

“Clouds make warm conditions cooler and cold conditions warmer.”
Yes, but cloudiness increases during the day and decreases at night. Particularly in the tropics.

Thomas Homer

tty: “Yes, but cloudiness increases during the day and decreases at night. Particularly in the tropics.”
Now you want to introduce variances in day/night behavior, immediately after clouds have finally been recognized as having an impact?
Perhaps clouds shield the Earth’s surface from direct sunshine during the day, keeping it cooler than clear skies. Perhaps clouds at night tend to keep the surface warmer than clear skies would.
Perhaps it’s the atmospheric moisture content that drives temperature. Look at the graph image I posted above. Perhaps each end of that curve drives the temperature towards the apex.


I really like the parasol idiom, but the “sopisticated numerical models” bit worries me after hearing Svensmark’s remark on Kirkby’s CERN CLOUD experiment – they used sophisticated numerical models (and the Cern HPC cloud) for aerosol CCN of 50nm , NOT actual experimental data (which only covered the early aerosol production phase 1-3nm).
Henrik Svensmark NEWS On Cosmic Rays, Clouds and Climate – Mar 2018

Alan Tomalty

“She will use satellite retrievals and sophisticated numerical models to help answer this question.”
That one sentence tells us just how stupid she is . Average intelligence of a climate modeller. Climate models can never model clouds correctly. They cant get the resolution. To get the resolution needed ( molecule size) you would need computing power on the order of the energy of this universe. MANKIND WILL NEVER BE ABLE TO MODEL CLOUDS CORRECTLY. The most futile human objective ever dreamed up.


Alan, since early days when I started following AGW I have talked to fairly honest scientists and modelers that stated very clearly that clouds hold the key to modeling the atmosphere and ultimately the climate. They also said most models at the time either did not attempt to model clouds at all or didn’t do it very well due primarily to the extreme additional complexity. Some said that the atmosphere was the most complex natural system ever modeled but until we figured out how to model water vapor we would never understand it enough to make predictions for the future. They also said the same thing about modeling the ocean-atmospheric interface, my interest at the time.

Alan Tomalty

So you agree with me?

J Mac

“….sophisticated numerical models…”
Sophisticated means ‘developed to a high degree of complexity’.
The root of the word is Sophist, which means ‘An individual who uses subtly deceptive reasoning or argumentation’. And that describes most of the purveyors of man made global warming.

It is about time to investigate this aspect of the climate equation!!!

Don Mattox

It is called Albedo.


And is the first cousin of convection.


Barbie discovers clouds.

Yogi Bear

“In a nutshell, with a −1.6%per decade change in cloud cover during 1954–2005, it becomes a climate forcing.”
More like a negative feedback to declining solar wind strength since the mid 1990’s.


In addition to the galactic cosmic ray theory, there should be more detailed studies of how land and ocean use changes impact cloud formation.
Trees emit cloud condensation nuclei, irrigation can change weather patterns on a regional scale, plankton populations emit cloud condensation nuclei, plankton populations change the distribution of sunlight absorption in the ocean (concentrating heat in the surface). Many human activities have changed the distribution of plankton in the oceans.
With a good enough model, you might be able to control plankton populations well enough to reduce the intensity of droughts.


The argument that clouds are acting as a sunshade doesn’t agree with the paper.

Increased clear sky frequency and decreased overcast frequency in China should have resulted in brightening, however, it has been completely offset by significant decrease of atmospheric transmittance under clear sky and cloudy condition, which resulted in dimming in China.

Rich Davis

Every day an amazing new discovery in Climate Change (TM).
It’s a little nebulous, but as I understand it, “clouds” consist of anti-CO2. That is, they do the opposite of CO2, they cool the planet. I feel very confident that these folks are on the verge of the “creation of solid facts as a basis for political decisions”.
Has anybody seen one of these things in a model? It may work in practice, but does it work in theory?


“It’s a little nebulous, but as I understand it, “clouds” consist of anti-CO2.”
As you suggest …it is all a little hazy.
like the QUESTION : If you have antipasto and pasta at the SAME MEAL are you STILL hungry ?

Rich Davis

Well, Trevor, I should think it was obvious that it depends on the ratio of pasta to antipasto. A sufficient excess of one or the other results in satiety. A stoichiometric ratio would be problematic, right? All of my sophisticated numerical models prove this settled nutritional science. Don’t be obtuse.


Rich Davis : “Don’t be obtuse ”
That’s alright for you to say !
I can’t help it !
ps. I do like the Mother Goose contribution Pop !

John harmsworth

My computer model says that every ounce of either that I eat will cause a CATASTROPHIC one pound weight gain due to “feedfront”.
Hey! Don’t look at me. The computer says so!

Rich Davis

Well John H, if the model proves it, I would be a raving lunatic to argue further on the basis of antiquated patriarchal and racist concepts of conservation of mass.
Wear black to hide the incline.


England tells much the same story as China.
Since 1930 there has been a much closer link to changes in sunshine amounts “cloud cover” and changes in temps. Then there ever has been to CO2 levels.

The leading research on global dimming/brightening is done at ETH Zurich. Senior scientist Martin Wild reported this:comment image
Details at:


India and China dimming might be due to more soot and other pollution in the air.

No doubt Felix. Dimming is a function of both cloudiness and aerosols. But there are measures showing cloud reduction (brightening) 1983 to 2002.

John harmsworth

One question. why do they do China? Mongolia but not Canada with the U.S.? Only missing 3.9 million square mile there. But then they have values for Japan?

John, it has to do concentrations of the sensors recording solar SW. As I read ETH Zurich docs, the network has grown slowly since the 1960s. I don’t know about Canada, maybe too much unsampled space far north.

John harmsworth

Thanks Ron, but I very much doubt that Mongolia is better sampled than Canada.

Stuart Nachman

I think I discovered this phenomena when I was about 8 years old. Unfortunately I didn’t know how to get published at that time.

Pop Piasa

Maybe now my nursery rhyme will be adopted by educators.
Mother Goose on Climate Prediction
As record winds blow
Unprecedented snow,
Oh, where is our globe a’ warming?
That depends on the sun
And the ways oceans run,
Plus clouds (with complexity) forming!
Now, for quite long,
Climate models are wrong.
So, what caused the pause in the warming?
Yes, look to the sun,
The ways oceans run,
And the clouds, in complexity forming.
CO2 is “too small”
To stop temperature’s fall
When the sun, clouds and oceans together,
Begin to cause cold
In cycles so old…
No one alive can remember!
So if I do some harm
By just keeping warm,
You’ll have to kindly forgive me!
I find my solution
Makes carbon pollution;
Lest Gaia too quickly outlives me!

John harmsworth

Bravo! Very smooth.

Tom in Florida

Anyone who has ever used a beach umbrella knows this.

John harmsworth

I took my umbrella to the beach but then it was cloudy anyway so that made it cool but the breeze was off the water which was warm so it tempered the coolness so I took down my umbrella and the sun came out and it got hot but then a guy tripped with a cooler full of ice water and dumped it all over me so then I dried off and I was ok until it got too hot so I put the umbrella up again.
The Global Warming was incredible. Probably 1/10 of a degree or so!

John harmsworth

Should I take my jacket off?


Estimates vary but about 67% or so of earth’s surface is covered by clouds on average.
NASA est from 2004 satellite data has 70%.
Question is how has it changed over time? And to what effect?

Pop Piasa

There’s a definite lack of cloud data to compare the analogous years in weather to cloud cover statistics then and now.

See Figure 11 at comment 5/12/ 6;22 Am below. Don’t worry about weather – look at the general trends of the millennial cycle.


Well, I sincerely hope that at least one of the chosen 13 experts has detailed knowledge on the thermodynamic behaviour of water and the mechanism of the Rankine Cycle in the transport of some 680 WattHrs of energy per Kilogram of water evaporated from the surface up into those clouds. Unless this is addressed there is little point in looking for answers in a mass of manipulated data.
For instance: How much energy does it take to pump millions of Tonnes of water up some Kilometers into the atmosphere in the the clouds? How is it done? Where does the energy come from?
Engineers know all this; but do these people know it? Engineers deal in Enthalpy and consider radiation merely as the enthalpy transfer mechanism. Engineers know that temperature is only one indicator of enthalpy amongst many. Engineers know what happens when phase changes take place where temperature is involved. Engineers know that the base calibration of global temperature (within constraints) is gravity where water is involved.
I just hope these people look at these aspects before they waste their time on boring statistical budgets to tease out dubious conclusions.

Rich Davis

Did you think that the purpose of this enterprise was the discovery of scientific fact? Sorry, this is not a matter of discovery, it is a matter of the creation of a narrative for political purposes. We need to get the Climate Change (TM) train back on track.
It says very clearly in the article:

The German-French program “Make Our Planet Great Again“ seeks to support the creation of solid facts as a basis for political decisions in the fields “climate change”, “earth system research” and “energy transformation”.

Now perhaps that’s a clunky translation from the German, but “the creation of solid facts” sounds more like “how can we make the predetermined narrative believable” than “follow the data to wherever it leads us”.
I guess that we should expect that the purpose of having a cloud researcher on board who has “evaluated the impact of ship emissions on clouds” would be to explain how human pollution has been deflecting some of the heat, temporarily causing a false sense of security of die Pause. Any day now, overheating from CO2 will come roaring back don’t you know? Alles klar?

John harmsworth

The French and Germans have no fossil fuels to speak of and are entirely too dependent on Russia, which can’t resist using oils and gas for political gamesmanship. That is why everything that France/Germany can touch on climate will prejudiciously determine that fossil fuels are evil. They seek to destroy the advantage that other countries have in this respect.
It is stupid anyway because cheap energy produces greater wealth everywhere, even in countries that don’t have cheap energy.

Chris Wright

“……the creation of solid facts…”
Hopefully this is a mis-translation. If not, it’s very worrying.
Honest people discover facts, they don’t create them.
If people literally create facts, then by definition it’s fake news and probably propaganda.
Unfortunately, creating facts (e.g. with climate models) seems to be very common in climate science.

Doug MacKenzie

“The thirteen scientists were selected during a two-stage process out of approximately 300 applications.” Could one presume the selection would be based on whatever the applicants’ resume stated was their personal “climate change” goal , and how closely that matched that of the selection committee (likely “helping mankind solve the climate crisis”) ? Or would they select them based on their credentials in atmospheric thermodynamics….say maybe meteorologists who actually study that sort of thing so they can read tephigrams, but they probably didn’t make the cut….

John harmsworth

See above. France and Germany have practical reasons for attacking fossil fuels so this investigational body will be constructed to do the opposite of what it says it is supposed to do.

Julian Flood

CCN numbers will, to a large extent, determine the amount of cloud. CCNs are made by breaking waves, dust, exhalations (various) by living organisms. Anything reducing CCN production will reduce albedo.
Humans fix as much nitrogen as Nature does. Does this alter CCN production by, for example, changing plankton populations? We pollute the oceans with dissolved siica, oil, fertiliser, etc. Does this? It’s almost inconceivable that our activities are not reflected in CCN numbers.
Has anybody looked?


This is a cirrius issue.
(Misspelling deliberate)

Bruce Sanson

please compare the graph of cloud optical thickness available here with this graph of deep water upwelling . If the rate of deep water upwelling varies over time then it seems likely the optical thickness of clouds also varies. This raises the possibility that variations in total sea ice production, wind speeds, southern vs northern hemisphere insolation, ENSO, could all play a roll in the amount of sunlight reflected back into space.

Keith J

Clouds also indicate convection and areas of increased conduction. Cumulus clouds are used by sailplane pilots as indicators of convection, often turning over as virga.
The troposphere is a water vapor driven thermodynamic system.


Now I’m confused. Are clouds a Good Thing, to be encouraged, or a Bad Thing, to be legislated against?


Next they will tax clouds, which is really bad news for the UK

I have enjoyed the approach that Willis has taken to revealing the intricacies of ocean thermal release and cloud formation and effects.
I look forward to further revelations.

See Figure 11 from my 2017 papercomment image
Fig.11 Tropical cloud cover and global air temperature (29)
“The global millennial temperature rising trend seen in Fig11 (29) from 1984 to the peak and trend inversion point in the Hadcrut3 data at 2003/4 is the inverse correlative of the Tropical Cloud Cover fall from 1984 to the Millennial trend change at 2002. The lags in these trends from the solar activity peak at 1991-Fig 10 – are 12 and 11 years respectively. These correlations suggest possible teleconnections between the GCR flux, clouds and global temperatures”
Here is the abstract. – check Figs 10 and 12.
The coming cooling: usefully accurate climate forecasting for policy makers.
DOI: 10.1177/0958305X16686488
Energy & Environment
0(0) 1–18
(C )The Author(s) 2017
This paper argues that the methods used by the establishment climate science community are not fit for purpose and that a new forecasting paradigm should be adopted. Earth’s climate is the result of resonances and beats between various quasi-cyclic processes of varying wavelengths. It is not possible to forecast the future unless we have a good understanding of where the earth is in time in relation to the current phases of those different interacting natural quasi periodicities. Evidence is presented specifying the timing and amplitude of the natural 60+/- year and, more importantly, 1,000 year periodicities (observed emergent behaviors) that are so obvious in the temperature record. Data related to the solar climate driver is discussed and the solar cycle 22 low in the neutron count (high solar activity) in 1991 is identified as a solar activity millennial peak and correlated with the millennial peak -inversion point – in the RSS temperature trend in about 2003. The cyclic trends are projected forward and predict a probable general temperature decline in the coming decades and centuries. Estimates of the timing and amplitude of the coming cooling are made. If the real climate outcomes follow a trend which approaches the near term forecasts of this working hypothesis, the divergence between the IPCC forecasts and those projected by this paper will be so large by 2021 as to make the current, supposedly actionable, level of confidence in the IPCC forecasts untenable.

“Anna Possner’s research focuses on layered clouds in the lowest kilometres of the atmosphere, which act as a semi-transparent parasol for Earth’s surface. They reflect a significant portion of incoming sunlight, but only marginally affect Earth’s heat emission”
Umm … LOL! You probably need to be an academic climatologist to claim such nonsense. Otherwise the facts are pretty obvious. Clouds are emitting – or rather reflecting – huge amounts of radiation back to the surface. Just take a look at this video, that has been taken at surface temperatures around 5-10°C (not by myself!):

That means low level opaque clouds will provide almost as much radiation as the surface itself. If the surface (which is mandatory for GHE “fake”-model) emitted like 390W/m2 and the cloud feedback was only 30W/m2 (as in the AR5 of the IPCC) such clouds might only cover like 30/390 = 7.7% of the surface.
You may want to consider all kind of abundances of different kinds of clouds and so on, but you will never get to a mere 30W/m2. And that is exactly the problem with the faked GHE, because it insists on that clouds just “marginally affect Earth’s heat emission”. No, they do not! They have a massive impact! An impact that climatologists wrongly like to affiliate with GHGs.


I find articles of this nature extraordinary as they reveal that the scientists involved have NOT done their homework. The basic thermodynamics of water is well known and if you understand it you will know that it is gravity which determines the mean temperature of the earth and that does not change very much. It is to do with the temperature at which water starts to evaporate depending on the prevailing pressure which in turn is a function of gravity.
Anecdotal evidence shows that water boils at 100 C at sea level and merely boils a bit faster if you turn the heat up. This is a specific point in the curve and remains constant at this 100 deg.C more or less. Those two observations should tell them all they need to know if they then apply the thermodynamics to explain why.
The process is the Rankine Cycle and provides the thermostat for the earth albeit with constraints. Water is very good at cooling things but not so good at warming should temperatures drop too far.
Merely looking at the Steam Tables reveals that some 680 WattsHrs on energy for every Kilogram of water evaporated from the surface winds up being dissipated into the atmosphere and beyond. And all this is done in reaction to variations in enthalpy/heat input.
Some day this might dawn on the green blob and if you doubt what I say ask yourself why in the history of the earth the temperature has remained so remarkably constant.