Nature Turns Up The Sunshine

Guest Post by Willis Eschenbach (@WEschenbach on X, my personal blog is here)

For the usual unknown reasons that are so common in my life, I got to thinking about sunshine hours.

Several people have noted that the decreased total albedo in the CERES dataset not only provides the additional energy necessary to explain a quarter-century of warming. It also gives changes in the total absorbed solar radiation (ASR, incoming solar radiation minus reflected solar radiation) that match up very nicely with the warming.

Figure 1. Normalized ASR and surface upwelling longwave radiation. “Normalized” means set to have an average of zero and a standard deviation of one.

Now, a problem with the CERES data is that it only covers the last 25 years. So in place of albedo, I thought I’d look at “sunshine hours” instead. This is the percentage of the daylight hours of a day, week, month, or year during which the sun is shining. It’s not albedo, but it’s related. Some research showed that the longest dataset we have is from Oxford in the UK. Here is that record.

Figure 2. Annual percentage of the daylight hours during which the sun is shining in Oxford, UK. Yellow line is a CEEMD smooth of the data.

Hmmm, sez I … most interesting. Although this isn’t the same as ASR, it’s most definitely increasing.

Next, I looked at Europe. Copernicus has a dataset showing sunshine hours there. It’s shorter, starting only in 1983. Figure 3 shows the Copernicus data.

Figure 3. Average annual percentage of the daylight hours during which the sun is shining in Europe. Yellow line is a CEEMD smooth of the data.

So I kept looking. My next dataset was from the US. Before ~ 1900, coverage is sparse, but after 1900, there are over 100 stations that record sunshine hours. So I didn’t try to area- weight them, I just took a straight average.

Figure 4. Average annual percentage of the daylight hours during which the sun is shining in the US. Yellow line is a CEEMD smooth of the data.

[UPDATE] An alert reader, JohnC, located a sunshine hours graph for the entire UK here. This is their graph.



Having seen that the percentage of sunshine hours was increasing in all the datasets I could find, and having seen that the CERES absorbed solar radiation was increasing, I turned back to the CERES dataset. Recall that “ASR”, the absorbed solar radiation, is the top-of-atmosphere solar radiation minus the solar reflections from the clouds, aerosols, and the surface. Here’s what’s happening with the ASR, shown along with the theoretical increase in forcing due to CO2.

Figure 5. Global monthly absorbed solar radiation (ASR, solar radiation minus reflected solar radiation), and the theoretical increase in “forcing” (downwelling radiation due to CO2) over the same period.

Now, bear in mind that one of the core arguments of the advocates of the idea that CO2 alone causes the recent global warming is that there is no natural explanation for the warming. Here’s the IPCC making that argument, that if the models are only given natural forcings, they can’t replicate the increase in temperature.

Figure 6. Models with natural forcings (blue) and natural plus anthropogenic forcings (red)

But as the ASR data above shows, the change in albedo provides enough solar power to explain the temperature increase without greenhouse gases.

However, note that this does NOT mean that greenhouse gases have no role in setting the temperature. It only means that they are merely part of the story. As I showed in my recently published peer-reviewed study entitled “Computational implementation and empirical validation of a Constructal climate model“, you need both the albedo and the greenhouse gases to explain the changes in the Earth’s temperature.

Blue springtime skies today, lots of sunshine hours, and plenty of outside maintenance calling me … my best regards to all on this most awesome planet.

w.

As Is My Wont: I ask that when you comment, you quote the exact words you are discussing. It keeps the thread from getting lost in misunderstandings.

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121 Comments
May 31, 2026 10:11 am

Excellent post, WE. I had not thought about simple sunshine hours before. Overcomes the ‘short’ CERES time frame.

May 31, 2026 10:14 am

8 climate experts, 8 different models, 8 different albedos & a 20 W/m^2 variance.
7 say net cooling, 1 net warming.
1 says the 7 are wrong.

Here’s your own copy.

Have not drawn much fire on the following WUWT post. A few negative swipes but no actual comments. Guess that’s because it does not need a PhD (Knows everything about everything and wrong about none of it.) to obfuscate w esoteric handwavium. Any unwashed prole who can balance a checkbook can spot the egregious errors.

The GHE debate is not just about the alarmist’s hocus pocus thermodynamic handwavium, but simple bookkeeping, i.e. 63 + 63 = 63.

TFK_bams09 and all of its clones don’t just violate LoT (160 in & 396 out LoT1 & 333 “back” from cold to warm wo work LoT 2) but basic GAAP.

The same 63 W/m^2 LWIR appears twice, once from the real solar balance: 160 – 80 – 17 = 1st 63 & again from the calc’d/“measured”/imaginary surface BB 396 – 333 “back” = 2nd 63.
The second appears in the calcs (356-333=23+40), the first does not. 

What happened? Is the real 63s absence error or deceit??

Only one of these loops is needed to balance OLR at ToA so that means the other is “extra” (violates LoT1) free floating, unaccounted for, looking for a home and apparently dropped down someone’s boot top.

Only one of these balance loops belongs on the graphic.
I suggest keeping the real one. 
The imaginary one can join RCP 8.5 in the trash bin of failed science.

K-T-Balance-w-8-Models
Reply to  Nicholas Schroeder
May 31, 2026 11:10 am

Nicholas…I see you’ve added a red box to your weekly yellow box nonsense where you fail to understand 396-333 of electromagntic flux IS the 63 watts of heat radiation and the 63 watts that LEAVES the surface….ENTERS the air above…it’s called “conservation of energy”…GAAP is for tax lawyers. And 63+80+17=160 the sunlight absorbed, also conservation of energy….And despite your claims ground level…balances….light blue lower atmosphere…balances….dark blue upper atmosphere….balances….It appears you simply cherry pick the same numbers crossing each layer to make it look like there is an arithmetic error…when there isn’t.

Reply to  DMacKenzie
May 31, 2026 5:56 pm

Nice . . . thus falsifying Nicholas Schroeder’s posted claim that:

“Have not drawn much fire on the following WUWT post. A few negative swipes but no actual comments.”

No matter how many times he (she?) repeats these same words, they always end up being incorrect and illogical. Just one example (presented, of course, to provide Nicholas with an “actual comment”): there is no such thing as his reference to blackbody (“BB”) radiation off Earth’s surface.

Reply to  DMacKenzie
May 31, 2026 7:48 pm

I’m curious, where does the 333 W/m^2 ‘back radiation’ come from and how is it measured. Please be specific. Thanks!

Reply to  Frank from NoVA
May 31, 2026 9:47 pm

Mostly cloud bases, also water vapor and CO2 in the atmosphere (low emissivity but long beam length).
Read a Kipp and Zonen manual for specifics.
https://www.kippzonen.com/products/cmp22_pyranometer
And maybe search “how does a pyrgeometer work”

Reply to  DMacKenzie
June 1, 2026 4:32 am

‘Mostly cloud bases, also water vapor and CO2 in the atmosphere…’

So mostly emissions from ice crystals and water droplets, i.e., condensed matter, and within the atmospheric window, right?

How about emissions from water vapor and CO2? Originating from the wild blue yonder, or simply the poly-directional radiance of air parcels in the immediate vicinity of the pyrgeometer?

Finally, do pyrgeometers actually measure the direction and magnitude of energy flow, or are these inferred from the phenomenological physics of radiative transfer theory?

Reply to  Frank from NoVA
June 1, 2026 6:16 am

1) Yes 2) Yes 3) it’s not “simply”…whole semester courses are based on understanding the basics to the point of putting numbers to them 4) experiment and calibration…same scientific methodology that experiments and calibration of expansion of mercury in a glass tube thermometer resulted in a readout of something we call temperature. “Inferred” implies a weak connotation…radiative physics is very strongly supportable by experiment…my experience, not merely opinion, plus millions of STEM folks worldwide too….no political philosophies involved…

Reply to  DMacKenzie
June 1, 2026 8:43 am

‘…same scientific methodology that experiments and calibration of expansion of mercury in a glass tube thermometer resulted in a readout of something we call temperature.’

Nice strawman! The ‘inferrence’ isn’t a problem with radiative physics per se, it’s the application of radiative transfer theory to atmospheric gases with the assumption that these exhibit the same radiative properties as do solids and liquids. That’s not just a ‘weak connotation’, it’s a conjecture, hence phenomenological physics.

Let’s focus again on the 333 W/m^2 of ‘back radiation’ from Trenbeth’s cartoon – that looks like a vector, i.e., it has direction and magnitude. Has it been measured with a yet to be invented Poynting meter or is it just the result from an ad-hoc, but convenient, model for tropospheric energy flow that avoids having to deal with the real processes and complexity of a convective troposphere?

Reply to  Frank from NoVA
June 1, 2026 9:46 am

Sounds like you are complicating the issue with Poynting vectors and thought processes you don’t need. Hemispherical flux just needs a flat surface to measure. FY reading pleasure:
https://wattsupwiththat.com/2026/03/31/toa-eei-versus-surface-net-flux/#comment-4180181

Reply to  DMacKenzie
June 1, 2026 11:15 am

Thanks – aways grateful when someone refers me to one of Andy May’s excellent comments. If I recall, Andy’s issue there was that, unbeknownst to the most of us, some of the radiative ‘flows’ in the cartoon were on a ‘gross’ basis vs. a ‘net’ basis, which is probably his more polite way of saying that the cartoon’s creators were dealing in junk physics.

So I don’t think I’m complicating the issue anywhere near as much as the ‘modelers’ have taken some serious liberties with the science in order to come up with an energy transport mechanism for the troposphere that is many orders of magnitude more tractable than dealing, say, with the Navier-Stokes equations for turbulent flows in viscous fluids.

I should point out at this time, that I’m not against using ad-hoc approximations or heuristics to obtain reasonably accurate solutions to otherwise intractable problems. All of us do that at some point. But the specific issue at hand is that many people, including those who would nefariously seek to control the lives of others, look at that 333 W/m^2 ‘flow’ and conclude that emitting more CO2 will result in warming, which is a not a result that is backed up by real observations from carbonate rock or ice cores.

Reply to  Frank from NoVA
June 1, 2026 7:49 pm

Frank, I never said anything about more CO2 causing much warming…If you want my opinion on that…it’s that the 4 watts extra IR absorption added by doubling CO2 isn’t enough to much affect that 1 meter square by 70 km tall column of air weighing 10 tons and that we live at the bottom of…maybe a degree warmer at the bottom if convection doesn’t carry the heated air, water vapor, and clouds along with it…up to a higher altitude where it can more easily radiate to outer space….

Reply to  DMacKenzie
June 2, 2026 8:06 am

Your opinion is sound in that it is certainly consistent with the findings of scientists like van Winjgaarden & Happer, who have diligently applied radiative transfer models to investigate the results of various GHG concentrations.

Where we differ is whether or not radiative transfer models actually explain how the bulk of the thermal energy emitted from the Earth’s surface is transported through the atmosphere to where it can eventually radiate to space. Based on your last comment, you might hopefully be open to looking at an alternative explanation that doesn’t require the hand-waving (phenomenology) of the former to be plausible.

https://andymaypetrophysicist.com/wp-content/uploads/2025/01/Shula_Ott_Collaboration_Rev_5_Multipart_For_Wuwt_16jul2024.pdf

Reply to  Frank from NoVA
June 2, 2026 4:40 pm

I’m missing the nuance of what you say I’m missing…
You say “it’s conjecture…”….hmmm, thousands of experimental results have been put into the Hitran database so that the absorption at whatever frequency of nearly any gas mixture at any pressure you imagine can be calculated. That what W&H use…and it’s a long, long ways from “phenomenology”.

Which is defined as:
Phenomenology is the philosophical study of conscious experience from the first-person point of view. It explores how we perceive, interpret, and assign meaning to the world around us, focusing entirely on “lived experience” rather than objective, scientific explanations.

And I like Andy’s articles too…

Reply to  DMacKenzie
June 2, 2026 10:18 pm

‘…thousands of experimental results have been put into the Hitran database so that the absorption at whatever frequency of nearly any gas mixture at any pressure you imagine can be calculated.’

Does HITRAN account for the fact that thermal radiation absorbed by GHGs is converted to sensible heat via collisions with non-IR active gas species within +/- 10 meters of the Earth’s surface? Or that the ratio of this non-radiative deactivation to spontaneous emission is on the order of 50K:1?

As for ‘phenomenology’:

‘A physical theory is called phenomenological if it expresses
mathematically the results of observed phenomena without clarifying their fundamental origin and significance. Typically, the development of a phenomenological theory is based on experience-based heuristic short-cuts lacking rigorous justification. Most phenomenological theories are short-lived and get replaced by fundamental first-principle theories. However, as we discuss in this Essay, some phenomenologies can survive for centuries despite their inherently limited scientific value and eventually become an impediment to scientific progress. The Latin term “Phenomenologia” was introduced by the German Lutheran theologian and theosopher Christoph Friedrich Oetinger in 1736. Subsequently, the German term “Phänomenologie” was used by Lambert to name his “doctrine of appearance”. It should be noted that Lambert viewed his photometry as a phenomenological discipline from the very outset.’

This ‘Essay’ is worth reading:

https://ntrs.nasa.gov/api/citations/20140012672/downloads/20140012672.pdf

Reply to  Frank from NoVA
June 3, 2026 8:05 am

1) “Does Hitran…?” …of course, many experimental results, especially air…2) “or the ratio 50K:1? ”… that’s frequency dependent. IIRC, about 80% of the photons in the 8 to 14 micron atmospheric window get all the way to outer space in a cloudless sky, but that’s only about 1/3 of the EMR of -65 to +85 C surfaces…at a 15 microns plus, they are absorbed in the first few meters….so 80% of 1/3 of the photons x 1/3 open sky x emission at 15C results in .8 X 1/3 x1/3 x 390 =35 watts to outer space directly…about what most heat budget Sankey diagrams show….German and Latin definitions ? Really? I do this over morning coffee…if it takes longer than that….it ain’t gonna happen…

Reply to  DMacKenzie
June 3, 2026 10:33 am

Yes, 50K:1 is the ball park ratio for CO2 (15 micron), which is why CO2 doesn’t spontaneously emit to space below the mesosphere (84km – see vW&H). NB: In a rational world, that would spell the end of CO2 back-radiation / alarmism, which is why it is necessary for CAGW skeptics to stop treating the phenomenological application of RTT to tropospheric energy transport as holy writ.

Yes, there is an ‘atmospheric window’ between ~ 8 to 14 microns, so most of that surface EMR escapes to space (neglecting some very minor overlap with water vapor), except for the portion that’s absorbed and re-emitted by dust, water droplets, ice particles and other forms of condensed matter. Interesting enough, this is the radiation that is detected by ‘hand held’ IR imagers pointed at clouds that even some well known skeptics erroneously posit as evidence of the 333 W/m^2 of ‘back radiation we initially talked about.

I understand that the time you have to look at this stuff is limited, but did want to ask if you have reviewed the Shula-Ott piece from Andy May’s site?

Reply to  Frank from NoVA
June 4, 2026 7:30 am

Yes, just now thanks to your mention…pretty good 1925 review of Schwarzchild equations with a bit on radiative equilibrium. Would say that Manabe in the 60’s has graphs that show the atmosphere is a ways away from radiative equilibrium. Sounds like we should have a beer over how “phenomenological” back radiation is..sometime.

Sparta Nova 4
Reply to  Nicholas Schroeder
June 1, 2026 7:16 am

Still using the graphic based on a flat earth model.

Reply to  Sparta Nova 4
June 1, 2026 9:59 am

Well the area of the “flat earth” model would be the area of the Earth
Pi x (6370 km)^2……while the spherical model would have a TOA sphere above the inner sphere at about 70 km higher.
And (6440/6370)^2=1.0221, so a piddling 2% discrepancy….

Sparta Nova 4
Reply to  DMacKenzie
June 2, 2026 6:44 am

Applying an average from a EM cross section to a sphere merely by averaging the cross section flux by the surface of the sphere is a flat earth model.

Also no geographic features on that smooth surfaced sphere. No angle of incidence affecting energy per square meter at various latitudes.

Does the north pole get that average in winter when the sun does not reach the surface?

2% is piddling, but a 0.6% “energy imbalance” is a crisis.

Reply to  Sparta Nova 4
June 2, 2026 7:46 am

It’s a matter of relative effect. The planet has about the same sphericity as a billiard ball. Heat transfer relations are about 10% accurate, measurement instruments 5%, and 0.6 is a scare tactic.

Reply to  Willis Eschenbach
June 4, 2026 7:35 am

Willis you are correct….SN4 doesn’t think the graphic – makers multiplied by the cosine of the incidence angle.

May 31, 2026 10:19 am

Is this original research as in nobody has plotted out changes in sunshine hours over time?

Richard Mott
May 31, 2026 10:21 am

Very interesting, but for the US data I concede area weighting isn’t necessary, but what about latitude and population growth patterns? They changed quite a bit since 1900. If more people move to “sunny California” because they like the sunshine, that might bias your results (assuming the station distribution roughly follows the population growth). Are you only counting stations that have been in existence for most of the study period?

Erik Magnuson
May 31, 2026 10:25 am

However, note that this does NOT mean that greenhouse gases have no role in setting the temperature. It only means that they are merely part of the story.

Very nicely put. I wish more people would consider that CO2 is only part of the story.

Reply to  Erik Magnuson
May 31, 2026 10:37 am

Yes, but let’s also not forget that for CO2 and AGW it is CO2 levels above the accepted baseline level of 280ppm.

Excellent work Willis, thank you.

Mr.
Reply to  Erik Magnuson
May 31, 2026 12:53 pm

Yes, but isn’t the CO2 control knob the only one with a dial that has its setting turned up to “11”?

Richard M
Reply to  Erik Magnuson
May 31, 2026 6:07 pm

If you have more solar energy warming the surface, you will get more upward IR radiation in the bands CO2 absorbs. Hence, even 280 ppm of CO2 would absorb more energy. As Willis indicated,

you need both the albedo and the greenhouse gases to explain the changes in the Earth’s temperature

True. But, this does not mean that more CO2 is needed. That’s a different question. As it turns out even 280 ppm would absorb all the extra energy shown in this situation. IOW, it would also be saturated very low in the atmosphere. Adding more CO2 would not add to the warming effect.

lwallace73@gmail.com
May 31, 2026 10:45 am

Love this effort.

  1. Figure numbers are screwed up (no Figure 1 mentioned in text; some other figures off by 1.
  2. If you were to replace your thick lines with a thin line showing the mean and a grey area showing the standard deviation or 95% range, would the resultant grey areas lie within or outside your thick lines?
Kevin Kilty
May 31, 2026 11:07 am

This is a very interesting post. The topic of sunshine is fraught with all sorts of nuance that people often just gloss over. I haven’t looked at any of the data in this essay, but several summers ago I put some discarded Eppley pyrometers back into service and simply observed their output over many days.

I live above 2,200m ASL and often our summer sky is absolutely clear. Or is it?

Some days I could see patches of tenuous cirrus clouds which were the knots, for lack of a better term, of two different sets of even more tenuous cirrus clouds that were in places subvisual. Visible or not, the passage of cirrus always affected the pyranometer, and even subvisual stuff could cause 10-15 W/m^2 of signal.

The various SURFRAD sites have a lot of this data going back into the early 1990s I think and might be another place to gather data. Unfortunately I don’t think the data is nearly so convenient to put together as CERES. What I have observed of it is files of data day by day.

Reply to  Kevin Kilty
May 31, 2026 6:43 pm

My new weather station has an output of insolation. I send it to Weather Underground so I can see a graph. You would be surprised how many clear days have significant areas where insolation is reduced by a significant amount and time. Not all of them are caused by low clouds.

May 31, 2026 12:02 pm

I thought the 2024-2025 temperature spike pushed the UAH data well out of the expected range for CO2 being the “control knob”, even adding in the strong El Nino from 2023-2024 (plus the temperature time lag for ENSO).

The Hunga Tonga event preceded the spike, but I have no firm conclusion about its effect since we do not have much comparison data during the modern instrument era.

However, if you combine Mr. Eschenbach’s Figure 5 ASR data with the timing of the strong El Nino, then the observed data in the UAH plot appears to become very well correlated to a significant increase in sunshine hours with the overprint of the spike in a cyclical temperature driver.

May 31, 2026 12:15 pm

Willis, I read your peer-reviewd paper with interest and as usual it contains a lot of common sense which is mostly missing these days.
However regarding the influence of increasing CO2 I would be interested in your view of the Lindzen Happer paper of 7th. June last year which proposes that more CO2 in the future will have little effect on temperature.

Best to the family.

David Roberts
May 31, 2026 12:18 pm

I wondered how sun shine hours were recorded prior to electronic technology. So I asked Gemini.

I expect Willis, you and many here new this, but for those like me that didn’t, here is an excerpt from its answer.

“The method has evolved significantly from the late 19th century to today.
1. Historical Recording: The Campbell-Stokes Recorder The long-standing record mentioned for Oxford (which began in 1880) relies on the Campbell-Stokes sunshine recorder.

  • The Device: It consists of a solid glass sphere acting as a lens, mounted in a metal frame. A specially treated card is held in a groove behind the sphere.
  • The Process: As the sun moves across the sky, the glass sphere focuses the sun’s rays onto the card, burning a continuous line into it.
  • The Limitation: When a cloud covers the sun, the burn stops. When the sun emerges, it starts again. However, this method is physically limited by the “threshold” of the paper—the sun must be strong enough to scorch the card. Consequently, this instrument is known to struggle with “bright” vs. “hazy” sun and often slightly overestimates duration during days with frequent, thin cloud cover, as the focal point may remain hot enough to leave a trace even when the sun is not perfectly clear.”
John Hultquist
Reply to  David Roberts
May 31, 2026 12:59 pm

Reminds me of a kid starting a fire with a magnifying glass.
Raise your hand if you were that kid.

Mikehig
May 31, 2026 12:22 pm

Willis, Thanks for a most interesting post.
You say, wrt sunshine hours: “It’s not albedo, but it’s related.”
Since we have data for both albedo and sunshine hours over the past 25 years, is that sufficient to see how they correlate?

Bob
May 31, 2026 1:33 pm

Very nice Willis this makes a lot of sense. Anthony, your adds are covering the comments.

gyan1
May 31, 2026 1:46 pm

I would love to see this increase calculated in W/m^2? All of the studies I’ve read using CERES data show the increase in solar radiation reaching the surface was far more than the increase in forcing from CO2 during the period. The IPCC’s position that most of modern warming was from human emissions is invalidated by this data.

Reply to  gyan1
May 31, 2026 6:00 pm

Presently a cubic meter of air has a mass of 1,290 g and contains a mere 0.85 g of CO2. This miniscule amount of CO2 can not absorb enough out-going long wavelength IR light to warm up such a large mass of air. This data also invalidates the claim by the corrupt IPCC that CO2 causes global warming.

gyan1
Reply to  Harold Pierce
May 31, 2026 6:30 pm

“This miniscule amount of CO2 can not absorb enough out-going long wavelength IR light to warm up such a large mass of air.” 

Physicists who have done the line by line radiative transfer calculations would disagree. 0.6C for a doubling is the central stand alone estimate. Because we lack the grid cell resolution to measure it directly in the free atmosphere it’s pure speculation what impact it actually has. The geologic record strongly suggests it is negligible.

Sparta Nova 4
Reply to  gyan1
June 1, 2026 7:38 am

Just a small point.
A calculation is equivalent to a computer model.

gyan1
Reply to  Sparta Nova 4
June 1, 2026 9:30 am

Calculations by physicists like Boris Smirnov who are experts at molecular heat transfer are not equivalent to alarmist computer models based on speculative fiction.

Sparta Nova 4
Reply to  gyan1
June 2, 2026 6:55 am

While that is likely true, my post was to a higher level than addressing specific calculations or models/simulations/emulations.

gyan1
Reply to  Sparta Nova 4
June 3, 2026 11:25 am

Calculations based on measurements are not equivalent to model based speculations climate pseudoscientists promote.

Sparta Nova 4
Reply to  Willis Eschenbach
June 2, 2026 6:51 am

Both depend on assumptions, explicitly stated, unrecognized by the performer, or deliberately embedded.

As to Einstein’s matter-energy equivalence theory, we cannot verify it. It is a repeatable calculation, much as V = I R (Ohm’s Law) is repeatable. With Ohm’s Law we are able to make measurements and conduct null hypothesis experiments.

We lack the ability to get matter up to the speed of light. Until then, it cannot be null hypothesis tested.

Do not misconstrue. I am not claiming that abbreviated form of the matter-energy equivalence equation is invalid or wrong. Just applying scientific method to the expression “verifiably true.”

Sparta Nova 4
Reply to  Sparta Nova 4
June 2, 2026 7:02 am

Perhaps I should clarify.
Both involve numerical operations.
Both involve assumptions.

Many simple calculations are assumption free, once the basic theory of mathematics is satisfied.

1+1=2 has the assumption that 1 is real and valid, for example, and also that numbers can be logically combined to create new numbers.

It has been 50 years since last I looked at the theory of mathematics and I have forgotten a lot.

Reply to  Harold Pierce
June 5, 2026 9:01 am

On the contrary the accompanying graph shows that the “minuscule amount of CO2” does indeed absorb a significant amount of heat.

comment image

May 31, 2026 2:11 pm

The increase in sunshine hours is probably due to a reduction in air pollution and in cloud cover. For many centuries, coal was used for space heating and for thermal energy for industry, but coal has been replaced by clean-burning natural gas especially for electrical power generation using CCGT technology. However, China and India are building many new coal-fired power plants and are probably not using the latest clean coal technology as does the US.

The increase in ASR might be due rubber particles and dust. Since 1900, where have the many billion pounds of rubber particle and dust from tires gone? The short answer is anywhere and everywhere.

Dieter Schultz
May 31, 2026 2:36 pm

But as the ASR data above shows, the change in albedo provides enough solar power to explain the temperature increase without greenhouse gases.

I would think that these graphs are really supporting evidence of Svensmark’s cosmic rays/cloud theory, aren’t they?

A stronger solar wind, pushes the heliosphere further out and it means that fewer cosmic rays will reach the level where nucleation can ‘seed’ the clouds meaning there will be fewer clouds to block the sun and, thus, more sunshine.

If I worked backwards from the graph showing a greater number of sunshine hours… well, I’d assume we would find a more extensive heliosphere and fewer cosmic rays available to form clouds.

Is that anywhere close to what is going on here? I mean, maybe it’s not and that would be useful information, but… since Svensmark’s theory isn’t even mentioned, I get the impression that these graphs are only part of the story that is being reported.

Nick Stokes
May 31, 2026 2:53 pm

 the change in albedo provides enough solar power to explain the temperature increase without greenhouse gases”

But it doesn’t explain. What caused that recent rise in sunshine hours, albedo drop etc?

Albedo feedback has long been part of AGW. Warmth, as it tends to do, evaporates water, and so clouds. That amplifies the warming from GHGs.

Dieter Schultz
Reply to  Nick Stokes
May 31, 2026 2:58 pm

What caused that recent rise in sunshine hours, albedo drop etc?

That was my question, although from a little different direction.

Why do we have more sunshine? There are possible explanation but… why not explore the issue a little more?

JonasM
Reply to  Dieter Schultz
May 31, 2026 3:07 pm

Why do we have more sunshine?

It’s the slowing of Earth’s rotation by 1.33 milliseconds per century. More time for the sun to shine. Duh.

/sarc

Reply to  Nick Stokes
May 31, 2026 3:46 pm

More clouds means higher albedo !

That amplifies the warming from GHGs.”

You can’t amplify something that doesn’t exist. !

Reply to  Nick Stokes
May 31, 2026 4:23 pm

Harold The Organic Chemist Says:
ATTN: Nick
RE: CO2 Does Not Cause Warming Of Air!

Shown in the chart (See below) is a plot of the annual mean temperature in Adelaide from 1857 to 1999. In 1857 the concentration of CO2 in dry air was
ca. 280 ppmv (0.52 g CO2 per cu. m. of air), and by 1999 it had increased to
368 ppmv (0.72 g CO2 per cu. m. of air), but there was no corresponding increase in air temperature in this port city. Instead there was cooling that began in ca. 1940. In 1857 Thi was 17.2° C and it declined to 16.7° C by 1999.

To obtain recent Adelaide temperature data I went to:
https//www.extremeweatherwatch.com/cities/adelaide/average-temperature-by-year. The Thi and Tlo data from 1887 to 2025 are displayed in long table. The computed Tav for 2025 was 17.4° C. Since measurement error is +/-0.1 ° C, it is concluded that CO2 has caused no warming of air in Adelaide since 1857. In 2025, the concentration of CO2 in dry air was 429 ppmv (0.84 g CO2 per cu. meter of air).
Please note and never ever forget how little CO2 there is in the air.

The chart was taken from the late John L. Daly’s website:
“Still Waiting For Greenhouse” available at http://www.john-daly.com. From the home page , go to end and click on: “Station Temperature Data”. On the
“World Map” click on “Australia”. There is displayed a list of stations. Click on “Adelaide”. To redisplay this list of stations click on the back arrow. Click on the back arrow again to display the “World Map”. Australian John Daly found over 200 weather stations that showed no warming of air up to 2002. Be sure to check all the charts for Australia.

The above empirical data and John Daly’s many charts falsifies the claims by the corrupt IPCC and the unscrupulous collaborating scientists that CO2 causes
“global warming” and is the “control knob” for climate change. It is time to putan end to all this CO2 global warming nonsense before it inflicts more harm on Australia.

NB: If you click on the chart, it will expand and become clear. Click on the “X” in the circle to contract the chart and return to “Comments”.

adelaide
Reply to  Harold Pierce
May 31, 2026 5:42 pm

DO NOT CLICK ON THE CHART. THE “X” IN THE CIRCLE FOR CONTRACTING THE CHART IS ABSENT. HERE IS THE CHART FOR DEATH VALLEY. DO NOT CLICK ON THIS CHART.

death-vy
Jeff Alberts
Reply to  Nick Stokes
May 31, 2026 5:06 pm

All clouds don’t amplify warming. Certain types do different things.

Nick Stokes
Reply to  Jeff Alberts
May 31, 2026 6:00 pm

Generally removing clouds leads to more SW at the surface. There i also an effect on IR, which could be cooling. But this article is about the effect on SW at the surface.

Reply to  Nick Stokes
May 31, 2026 6:49 pm

The decrease in cloud cover has led to an increase in absorbed solar radiation.

It causes warming !

Absorbed-solar-radiation
leefor
Reply to  Nick Stokes
May 31, 2026 9:45 pm

Albedo is a function of particles suspended in the atmosphere, clouds or not. Do those particles disappear?

Anthony Banton
Reply to  leefor
June 1, 2026 4:30 am

They get washed out. Many are hygroscopic and become cloud condensation nuclei.

hiskorr
Reply to  leefor
June 1, 2026 5:24 am

It is generally thought that non-H2O “particles suspended” provide nucleation for condensation of water vapor. To the extent that they do, they are “washed down” with the daily precipitation, which, as I’ve mentioned before, is roughly equal in weight to the total of CO2 in the atmosphere. As to affecting albedo, I’d suggest that H2O, whether clouds or surface ice, is much more effective than other atmospheric particles.

Reply to  Nick Stokes
June 1, 2026 7:18 am

But it doesn’t explain. What caused that recent rise in sunshine hours, albedo drop etc?

Perhaps the earth isn’t as compliant with homogenity as the models would have you believe. After all, do the models explain a habitable Greenland? Or are they incapable of maintaining sufficient regional change?

Reply to  Nick Stokes
June 1, 2026 7:29 am

‘Albedo feedback has long been part of AGW. Warmth, as it tends to do, evaporates water, and so clouds.’

Nick, some clarification, please. Are you saying that ‘warmth’ evaporates water AND reduces cloud cover? As for albedo feedback having ‘long been part of AGW’, I would point out that all the scenarios in AR6 (SSP1 – SSP6) project an INCREASE in albedo, so perhaps you, or one of your acolytes, can square that with the premise of this article, which is that albedo seems to be declining.

Sparta Nova 4
Reply to  Nick Stokes
June 1, 2026 7:40 am

Nick,

I am surprired at this. A few years back you did a clear and concise article on feedback.

dh-mtl
Reply to  Willis Eschenbach
June 2, 2026 5:07 am

Excellent Contribution – Thank you.

You say – ‘Note that there are large portions of the planet where, as you say, as the temperature rises the cloud albedo (and thus the clouds) decreases.’

I would say that this depends on whether clouds drive the temperature or temperature drives the clouds. Let me explain:

Your graph shows that over land, outside of the tropics, there is a very strong positive correlation between albedo and temperature. However over the tropical oceans the correlation is strongly negative. Over the oceans, outside of the tropics the correlations are much weaker.

So what are the differences:

  1. Temperature over land is much more sensitive to albedo than is the temperature over the oceans:
  2. The heat capacity of the earth is much lower than water (1 J/g-C for earth vs 4 j/g-C) for water.
  3. Solar energy does not penetrate the land, it stays on the surface, while much of the solar energy that is incident on the ocean penetrates deep into the oceans and is stored there, rather than released as heat.
  4. Over the tropical oceans (temperatures > 25C) the principle method of heat transfer from the ocean surface to the atmosphere is via water evaporation, and the rate of water evaporation is highly sensitive to temperature. Over land, outside of tropical forests, water evaporation has a limited role to play.

To summarize:

  • The correlation between albedo and temperature is strongly positive where the surface temperature is highly sensitive to solar energy and where water evaporation is limited. Here clouds drive temperature.
  • The correlation between albedo and temperature is strongly negative where the surface is much less sensitive to solar energy and where water evaporation is the principle method of transfer from the surface to the atmosphere. Here temperature drives clouds.
May 31, 2026 3:57 pm

Willis, this may be one of your best posts yet on an overlooked factor. Your paper looks intriguing, and I will find time to read it.

hiskorr
Reply to  Willis Eschenbach
June 1, 2026 5:45 am

I, too, enjoy your work, although contemplating “daylight hours when the sun is not shining” was a bit of a laugher.

BILLYT
May 31, 2026 4:00 pm

Could there be a mechanism where the consequence of CO2 rising results in more sunshine.

The Western European lift in sunshine hours must be due some change. What are the candidates.

Also the European area is quite unique climatically.

Nick Stokes
Reply to  BILLYT
May 31, 2026 4:04 pm

Could there be a mechanism”
Yes. Warming evaporates clouds.

Jeff Alberts
Reply to  Nick Stokes
May 31, 2026 5:07 pm

Or less cloud cover increases warming.

Reply to  Jeff Alberts
May 31, 2026 6:54 pm

CO2 does not cause warming, or affect clouds, so it is all totally natural.

Anthony Banton
Reply to  Jeff Alberts
June 1, 2026 4:38 am

Yes – a feed-back
Which is detailed here (in papers dating from 2009 and 2014 …..

2014
https://pmc.ncbi.nlm.nih.gov/articles/PMC4250165/

“The greenhouse effect is well-established. Increased concentrations of greenhouse gases, such as CO2, reduce the amount of outgoing longwave radiation (OLR) to space; thus, energy accumulates in the climate system, and the planet warms. However, climate models forced with CO2 reveal that global energy accumulation is, instead, primarily caused by an increase in absorbed solar radiation (ASR). This study resolves this apparent paradox. The solution is in the climate feedbacks that increase ASR with warming—the moistening of the atmosphere and the reduction of snow and sea ice cover. Observations and model simulations suggest that even though global warming is set into motion by greenhouse gases that reduce OLR, it is ultimately sustained by the climate feedbacks that enhance ASR.

2009
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009GL037527

“Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top-of-atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.”

Reply to  Anthony Banton
June 1, 2026 7:29 am

Clouds and sea ice are parameterised in the models. It’s a post-hoc argument from tuning.

Reply to  Anthony Banton
June 1, 2026 7:37 am

‘However, climate models forced with CO2 reveal that global energy accumulation is, instead, primarily caused by an increase in absorbed solar radiation (ASR).’

‘There is an increase in net radiation absorbed, but not in ways commonly assumed.’

I’ve quoted these articles on several occasions to the alarmists on this site. It’s gratifying that you now agree that the failure of observations to square with the canonical narrative of AGW has resulted in a desparate attempt to rescue the latter.

Nick Stokes
Reply to  Willis Eschenbach
May 31, 2026 7:52 pm

Willis,
I think what you are showing is a correlation based on places around the world. Equatorial is cloudy, etc. But it doesn’t tell you what happens at any one place when it gets warmer.

Reply to  Willis Eschenbach
June 1, 2026 10:16 am

Another Willis great graphic.

Reply to  Nick Stokes
May 31, 2026 6:50 pm

[don’t harass Nick]

Reply to  bnice2000
May 31, 2026 6:55 pm

I’m not. I’m just correcting his misunderstandings so everyone else can see them.

Reply to  bnice2000
May 31, 2026 7:07 pm

considering the quality of your “arguments” yes you are.

Reply to  Charles Rotter
May 31, 2026 8:00 pm

You mean.. basic facts !!

Reply to  bnice2000
May 31, 2026 8:12 pm

No, pathetic strawmen and category one logic errors.

Richard M
Reply to  Nick Stokes
May 31, 2026 7:07 pm

Nick is getting desperate. He is claiming more water vapor produces fewer clouds. LOL.

Nick Stokes
Reply to  Richard M
May 31, 2026 7:55 pm

Warmer air can hold more water as vapor But it is less likely to condense. The general observation is that specific humidity increases, but relative humidity decreases..

Reply to  Nick Stokes
June 1, 2026 6:59 am

Why don’t you stand in the shade for a few minutes then walk out into the full sun on a warm sunny day, the difference is obvious.

Why do you think humans and many animals seek the shade during a sunny summer afternoon…

Reply to  Nick Stokes
June 1, 2026 7:32 am

What kind of argument is this Nick? Clouds exist at the level they do condense. In a warmer world, that’s a little higher in the atmosphere.

Richard M
Reply to  Nick Stokes
June 1, 2026 8:18 am

According to Nick warming causes more water vapor which reduces clouds which causes more warming which causes more water vapor which reduces clouds which causes more warming which causes more water vapor which reduces clouds which …. completely eliminates all clouds in an atmosphere full of water vapor. LMAO.

Water vapor may condense at a slightly higher altitude in a warmer world but since there is more water vapor the convection currents will be stronger forcing the air higher into the colder parts of the troposphere. The clouds will even be thicker. Stop denying basic science.

Reply to  Richard M
May 31, 2026 8:02 pm

And less clouds means more solar working.

So he is saying the SUN is causing the warming… a fact we are all well aware of.

Anthony Banton
Reply to  Richard M
June 1, 2026 10:05 am

“Nick is getting desperate. He is claiming more water vapor produces fewer clouds. LOL.

It does.
What is crucial is the evironment in which that process occurs

Mesoscale meteorological physicsat work and not just empirical laws …

“AI Overview
Global warming decreases subtropical marine stratocumulus clouds primarily by raising sea surface temperatures, which increases atmospheric moisture and evaporation. This accelerates the mixing of dry air from above into the cloud layer, breaking the clouds apart. 

(because marine SC in the Trade zones lie under subsiding air from the sub-tropical jet – warm/dry.)

The Breakup Process
Reduced Cloud-Top Cooling: Stratocumulus clouds sustain themselves by emitting infrared radiation, which cools the cloud tops. Higher greenhouse gas concentrations trap this heat, weakening the cooling effect that keeps the clouds stable. 

Enhanced Evaporation: Warmer oceans increase evaporation. This enhances turbulent mixing, pulling dry air from above the clouds (the “free troposphere”) down into the cloud layer, which causes the clouds to dissipate. 

Decreased Inversion Strength: Global temperature changes can lift and weaken the “trade inversion” (a layer of warm air trapping cooler air below), letting the cloud moisture escape and thin out. 

Reduced Aerosols: Decreases in sulfur emissions from shipping have also reduced the tiny particles these clouds need to form, making them less reflective and harder to sustain. “

Reply to  Anthony Banton
June 5, 2026 10:18 am

You seem pretty sure you are correct over very speculative effects….

Reply to  Nick Stokes
June 1, 2026 7:22 am

Warming evaporates clouds.

Wot? A hundred meters higher it’s colder.

Reply to  BILLYT
May 31, 2026 4:58 pm

At the Mauna Loa Obs. in Hawaii, the concentration of CO2 in dry air is currently 431 ppmv.
One cubic meter of this air has mass of 1,290 g and contains a mere 0.847 g of CO2 at STP. This miniscule amount of CO2 can not absorb enough out-going long wavelength IR light emanating form the earth’s surface to heat up such a large mass of air.

The main process for warming of air is: surface heated by sunlight, air contacts warm surface,
warm air then rises up. H2O is the only greenhouse gas of importance and its greenhouse effect depends on specific humidity. In winter H2O and CO2 hibernate. In Death Valley the RH is 14%.

May 31, 2026 4:56 pm

Figure 2. Annual percentage of the daylight hours during which the sun is shining in Oxford, UK. Yellow line is a CEEMD smooth of the data.

That raises a whole lot of questions about what it means.

How was it measured? I am certain it would be an instrument rather than someone watching the sun. So what instrument?

What is the threshold of instrument operation? How much sun does it need to actually record? Could it be the solar intensity increasing (which it is from 10S to 50N. Could it be changing length from sunrise to sunset?

There is data available for Australia that might be worth looking into for a different hemispherical perspective.

The problem for AR7 is that the heat content of the oceans in the SH is decelerating and could well be negative before AR7 gets p[ublished. The hoax is dying.

Jeff Alberts
May 31, 2026 5:01 pm

CO2 is obviously causing more sunshine.

Reply to  Jeff Alberts
May 31, 2026 6:02 pm

Hmmm . . . put this question to Google’s AI bot and got this response:

“There is effectively no carbon dioxide (CO2) in the Sun. The Sun is a ball of plasma powered by nuclear fusion, and it is too hot for molecules like CO2 to exist.” 

/sarc^2

May 31, 2026 5:45 pm

From the above article:

“Now, bear in mind that one of the core arguments of the advocates of the idea that CO2 alone causes the recent global warming is that there is no natural explanation for the warming.”

My reply: variation in clouds, clouds, clouds and clouds (as quite a few commenters under this article have pointed out).

May 31, 2026 6:09 pm

The airy-fairy CO2 tiny trace gas control knob fantasy is totally eclipsed by the grinding rumble of tectonic activity. This planet is in an Icehouse State and has been for 34 million years because of tectonics – ACC – not CO2. And will continue so for at least 50 million years when tectonics might change that. 

Reply to  idbodbi
May 31, 2026 6:52 pm

And, as David Dibble has shown many time, any imaginary CO2 effect is totally dwarfed by energy transferred by mass air movement.

June 1, 2026 1:20 am

The attached image is for the U.K. for sunshine hours in July from 1910 to the present. This is from https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-temperature-rainfall-and-sunshine-time-series where you have to select the data type and the month.
I found this preprint that examines data across the U.K. interestingly, assuming I have read it right, it is in winter that shows the largest increase in sunshine hours with summer showing the least, spring and autumn/fall in between. https://www.researchgate.net/publication/369848632_Modelling_monthly_trends_in_sunshine_hours_for_the_United_Kingdom_and_its_regions

IMG_4271
Reply to  JohnC
June 4, 2026 2:17 pm

Most of the increase in Winter is in England, Northern Ireland and Scotland show no increase in Winter. Autumn sunshine hours are down in Northern Ireland and Wales. Spring sunshine hours are up in all regions, with AMO warming from 1995.

Denis
June 1, 2026 1:45 am

Dr. Humlum’s website, climate4you.com (go to climate+clouds) shows declining global cloud cover from about 64% to 61% from 1982 to 2019. More sunshine getting through should cause gradually increasing surface temperature. No? But then, our climate models don’t do clouds do they.

Reply to  Denis
June 1, 2026 2:54 am

Except in winter when clouds keep the temperature higher at night, preventing frosts.

Reply to  JohnC
June 1, 2026 7:11 am

It also keeps the day colder too thus a wash…

fmassen
June 2, 2026 9:17 am

I was manager of the meteolcd station in Diekirch, Luxembourg (Europe). Here the plots of the sunshine hours (derived from pyranometer readings) from 1998 to 2023:
https://ourclimate.lu/data/trends/meteolcd_trends.html
(scroll down to Sunshine Hours).
Clearly a positive trend!