Rethinking Climate, Climate Change, and Their Relationship with Water

New open access paper by Prof. Demetris Koutsoyiannis


We revisit the notion of climate, along with its historical evolution, tracing the origin of the modern concerns about climate. The notion (and the scientific term) of climate was established during the Greek antiquity in a geographical context and it acquired its statistical content (average weather) in modern times after meteorological measurements had become common. Yet the modern definitions of climate are seriously affected by the wrong perception of the previous two centuries that climate should regularly be constant, unless an external agent acts upon it. Therefore, we attempt to give a more rigorous definition of climate, consistent with the modern body of stochastics. We illustrate the definition by real-world data, which also exemplify the large climatic variability. Given this variability, the term “climate change” turns out to be scientifically unjustified. Specifically, it is a pleonasm as climate, like weather, has been ever-changing. Indeed, a historical investigation reveals that the aim in using that term is not scientific but political. Within the political aims, water issues have been greatly promoted by projecting future catastrophes while reversing true roles and causality directions. For this reason, we provide arguments that water is the main element that drives climate, and not the opposite.

And the summary


Given the hot and polarized discussions and actions about climate, it can be anticipated that many readers would find this paper useless, if not harmful. Actually, one of the aims of the paper is to show that polarization stems from political, rather than scientific, roots. Many scientists have paralleled their scientific profession with political aims (cf. “Marches for Science”). At the same time, mixing up science with politics has been promoted by many as a positive development. In contrast, this paper tries to promote the ancient ideal of science being separated from other interests, such as economic or political. It is recalled that Plato and Aristotle clarified the meaning and the ethical value of science as the pursuit of the truth; pursuit that is not driven by political and economic interests. For the latter, they used different terms, sophist (σοφιστής) and sophistry (σοφιστεία) [30,111–113].

In modern politics, fuzzy language and subjectivity may be desirable as they serve several purposes such as inclusiveness and diffusion of responsibility. In contrast, in science, the desiderata are rigour, clarity and objectivity. These desiderata may attribute some usefulness to this paper in clarifying concepts related to climate and water. Arguably, there is a strong need for such clarification if we accept that political influences should be left out.

Specifically, the current definitions of climate do not highlight its nonstatic nature. Rather, they imply a static climate, as already analysed (Section 3). Hopefully, the definition proposed and illustrated here (Section 4), which highlights the stochastic character of climate, could be useful to dispel this fallacy or, at least, provoke some discussion toward a more rigorous definition. By dispelling the fallacy, the term “climate change” would hopefully disappear from the scientific vocabulary and remain where it exactly belongs, i.e., the political vocabulary (Section 6). Dispelling another set of fallacies about the relationship of water and climate, also investigated here (Section 5) could be equally useful.

The potential usefulness relies on at least two facts. Highlighting the stochastic character of climate and its huge variability helps us understand the failure of current deterministic modelling approaches in describing past climate, and points to a potentially more promising direction in climate modelling within a stochastic framework. Highlighting the strong role of water in the climate can help shake the prevailing views on roles and causality chains in climatic processes, which may currently be opposite the real ones.

Full paper may be downloaded here.

HT/David H

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March 22, 2021 10:09 pm

Given this variability, the term “climate change” turns out to be scientifically unjustified.”

Yep! Been thinking and saying this for while.

Reply to  Mike
March 22, 2021 10:30 pm

Agree. But the essential and necessary facts the author points out that water drives climate is a step forward in debunking the climate change from CO2 nonsense.

Reply to  Leonard
March 23, 2021 1:50 am

Water doesn’t “drive” climate.

It helps CONTROL it, just like the atmospheric pressure gradient does.

Ron Long
Reply to  fred250
March 23, 2021 3:15 am

The physical state of the earths water budget also shows the physical state of a fair amount of water, when it’s colder glacial ice accumulates on continental masses in polar regions, and when its hotter they melt. In the first case sea level goes down, in the second it goes up. The part of geology known as “Sequence Stratigraphy” studies this, and all petroleum exploration companies utilize this tool.

Reply to  fred250
March 23, 2021 5:28 am

Absolutely, water evaporates and its vapour provides stabilising feedback within limits set by insolation.

Reply to  fred250
March 23, 2021 7:48 am

Boris Johnson’s paper ‘Daily Telegraph’ going more sceptic, nice but naughty, princess nut-nuts won’t like it as much.

Tom Abbott
Reply to  Vuk
March 23, 2021 9:33 am

The water vapor ups and downs match the temperature ups and downs displayed on the satellite chart shown.

If we were to substitute the instrument-era Hockey Stick chart, then the water vapor ups and downs would *not* match the temperature ups and downs of the Hockey Stick chart, since the Hockey Stick chart does not match the Satellite chart.

Conclusion: Water vapor puts the lie to the Hockey Stick chart.

Reply to  Tom Abbott
March 25, 2021 11:08 am

Hockey Stick chart does not match anything because it was a fraud.

Reply to  fred250
March 23, 2021 9:43 am

There was a time, not too long ago (geologically speaking) when southern Nevada hosted large forests of trees up to 6′ in diameter … then the Sierra Nevada was raised up and cut off the largest source of atmospheric water. Nevada now sits arid in the rain-shadow of The Sierra Nevada range.

Reply to  Mike
March 23, 2021 6:46 am

Both of my parents spent their adolescence on the Great Plains during the dust bowl. I heard lots of stories. I was also raised on the Great Plains but the climate was more benign than what my parents experienced.

It’s obvious to me that the climate can take a nasty turn for a prolonged period. What stuns me is that lots of people, with the same background as mine, manage not to have made that simple observation. They know about the Dirty Thirties. What the heck do they think was going on?

Climate change … it’s what the climate does.

Gerald Machnee
Reply to  commieBob
March 23, 2021 8:21 am

Today, that would be climate change. In the 1930’s it was weather or drought. As far as temperatures go, NASA/NOAA is lowering that period to eliminate it, so it cannot be climate change.

Dave Andrews
Reply to  Gerald Machnee
March 24, 2021 8:32 am

When are NASA/NOAA going to rewrite The Grapes of Wrath?

Dave O.
Reply to  commieBob
March 23, 2021 9:19 am

Will we have another “dirty thirties”? Most certainly, but the next time it will be labelled “human caused”, while the first dust bowl had far more human finger prints.

Reply to  Dave O.
March 23, 2021 9:33 am

The heat and the drought weren’t human caused. On the other hand, because of the farming practices, we nearly created a desert. link

Tim Gorman
Reply to  commieBob
March 23, 2021 4:18 pm

Human’s didn’t create the wind either. They facilitated its destruction by removing wind breaks but that didn’t cause the wind.

Mike Maguire
Reply to  commieBob
March 23, 2021 9:24 am

The Dust Bowl and Record heat for much of a decade really did happen!
comment image?resize=550%2C500

The 1930’s set more all time state high temperature records than any other decade…….that still stands!
U.S. state and territory temperature extremes

We’ve been told for over 3 decades that global warming will cause a return of the Dust Bowl conditions:

U.N. Predicts Disaster if Global Warming Not CheckedPETER JAMES SPIELMANNJune 29, 1989:
“Shifting climate patterns would bring back 1930s Dust Bowl conditions to Canadian and U.S. wheatlands”

Instead, with rising beneficial CO2 and slight, beneficially warmer temperatures, just the opposite has happened…..the planet is massively greening up, crop production soaring higher not in spite of Climate Change but BECAUSE of climate change:

Joel O'Bryan
March 22, 2021 10:41 pm

“The potential usefulness relies on at least two facts. Highlighting the stochastic character of climate and its huge variability helps us understand the failure of current deterministic modelling approaches in describing past climate, and points to a potentially more promising direction in climate modelling within a stochastic framework. Highlighting the strong role of water in the climate can help shake the prevailing views on roles and causality chains in climatic processes, which may currently be opposite the real ones.”

We live on a Blue water-rich planet.

As I have said in many WUWT posts on this topic, it is water, water in its 3 phase forms, that totally confounds the models, because those phase changes transmit so much energy to the TOA yet they do so at scale so small the modellers cannot model it. Most importantly we see it in clouds and albedo uncertainty. Uncertainty in cloud formaton makes the models junk science (besides other issues). Junk science all the way down. Follow that rabbit hole of lies to even more lies if you wish.

Reply to  Joel O'Bryan
March 23, 2021 12:05 am

I continue to learn and appreciate the many “core” Climate science articles on WUWT but that’s not where the war will be won.
There are multiple elements to the climate scam.
We need to challenge failed predictions and useless mitigation and adaptation policies.

Alan Robertson
March 22, 2021 11:11 pm

Yep, it’s a pleonasm, not a construct of scientific desiderata.
>facepalm goes here<

Tom Abbott
Reply to  Alan Robertson
March 23, 2021 9:39 am

I had to look it up. 🙂

March 22, 2021 11:37 pm

“By dispelling the fallacy, the term “climate change” would hopefully disappear…”

Not to worry, they are working on it, the new term is, “The Climate Crisis”

Tom Abbott
Reply to  Steve Case
March 23, 2021 9:41 am

I see where Biden wants to spend $400 billion on Climate Change in the coming “infrastructure” bill.

I haven’t seen any details on where he wants this money spent.

Reply to  Tom Abbott
March 23, 2021 6:47 pm

For the details, refer to his donor list.

Tom Abbott
Reply to  H.R.
March 24, 2021 4:52 am

Good point.

To bed B
March 22, 2021 11:43 pm

“It is recalled that Plato and Aristotle clarified the meaning and the ethical value of science as the pursuit of the truth; pursuit that is not driven by political and economic interests. For the latter, they used different terms, sophist (σοφιστής) and sophistry (σοφιστεία) [30,111–113].”

As in knowledge is knowing that a tomato is a fruit, while sophistry is knowing not to put it in a fruit salad.

March 23, 2021 12:42 am

Hydrology is the Real Science of Climate.

March 23, 2021 1:25 am

Letter to the Editor, NATURE 1992,

“Climate Change”, Vol. 360, p. 292;

SIR – The Earth Summit in Rio de Janeiro and the earlier struggle for a Convention on Climate Change may serve as a reminder that the 1982 Convention on the Law of the Sea has its tenth anniversary on 10 December. It is not only one of the most comprehensive and strongest international treaties ever negotiated but the best possible legal means to protect the global climate. But sadly, there has been little interest in using it for this purpose. For too long, climate has been defined as the average weather and Rio was not able to define it at all. Instead, the Climate Change Convention uses the term ‘climate system’, defining it as “the totality of the atmosphere, hydrosphere, biosphere and geosphere and their interactions”. All that this boils down to is ‘the interactions of the natural system’. What is the point of a legal term if it explains nothing? For decades, the real question has been who is responsible for the climate. Climate should have been defined as ‘the continuation of the oceans by other means’. Thus, the 1982 Convention could long since have been used to protect the climate. After all, it is the most powerful tool with which to force politicians and the community of states into actions.

Ron Long
March 23, 2021 3:12 am

This paper has many excellent points, like the continuous changing of the climate. In my mind Professor Demetrius shoots, he scores, he’s in the Final Four.

Reply to  Ron Long
March 23, 2021 12:20 pm

Flattered to read your comment, thanks!

March 23, 2021 3:17 am
Reply to  lee
March 23, 2021 3:20 am

The official site of the journal is this:
The review reports and my replies are also posted there.

Reply to  lee
March 25, 2021 12:56 am

The above ResearchGate link has changed to (with the corrected pdf).

March 23, 2021 3:17 am

I thank WUWT and all commenters for the post about my paper. I will be glad to reply to queries or disputes.


Reply to  Demetris Koutsoyiannis
March 23, 2021 7:15 am

Thank you sir for your excellent paper.

Among the references in the paper extracted above is your CO2 Hen or Egg paper. I won’t have time to read it for a day or so but I strongly suspect that it too should be covered by WUWT.

There is this interesting paper that covers CO2 solubility including pressures and temperatures that prevail in the deep ocean. If I’m interpreting it correctly (I’m not a chemist), a 0.1 C change in the deep ocean’s temperature would change its CO2 solubility enough to completely explain the current increase in atmospheric CO2.

The other thing I got from the solubility paper is that there is inconsistency in laboratory measurements of CO2 solubility. That would mean, of course, that CO2 solubility is not nearly as well understood as some folks would have us believe.

Reply to  commieBob
March 23, 2021 12:18 pm

Thanks for the kind words about my paper as well for pointing to the interesting paper about the solubility of CO2.

Reply to  commieBob
March 23, 2021 12:22 pm

Also thanks for mentioning my (and my coauthor’s) hen…

Reply to  Demetris Koutsoyiannis
March 23, 2021 7:16 am

Great paper Professor Koutsoyiannis. I enjoyed reading it very much and I agree with you on every point. As you say climate changes by definition, “climate change” is redundant and a pointless phrase. Water, in its various phases is the key climate regulator, as you say. This is a paper I need to keep close at hand.

Reply to  Andy May
March 23, 2021 12:15 pm

Thanks very much for the flattering comment. Delighted that you enjoyed reading the paper and agreed with it.

Bruce Cobb
March 23, 2021 5:10 am

Water isn’t the main driver of climate, though the oceans certainly play a big role. The sun is the big cahuna of climate. Water mainly helps regulate climate.

Reply to  Bruce Cobb
March 23, 2021 6:11 am

As any of us who live in areas that seasonally have high humidity would know, water not only regulates climate, but is definitely part of it.

Krishna Gans
Reply to  Bruce Cobb
March 23, 2021 8:24 am

Sun and water co-working is the key.

Reply to  Bruce Cobb
March 23, 2021 12:11 pm

Perhaps I would have stressed more that there not a single driver of climate. I discuss other drivers in the first two paragraphs of section 5.

Mumbles McGuirck
March 23, 2021 5:13 am

‘Many scientists have paralleled their scientific profession with political aims (cf. “Marches for Science”). ‘

The March For Science was neither organized nor managed by scientists. It was created by political people who co-opted scientists to speak at rallies but who were merely props. The same is true for marches for workers, immigrants, or ethnic minorities. All organized by leftist politicians whose grievances were not those of the groups manipulated but with democratic government and freedom as a whole. It was just that their puppets wore lab coats on stage this time.

Reply to  Mumbles McGuirck
March 23, 2021 11:17 pm

Irrespective of who organized or managed March for Science, there were scientists who participated. Some with pride. Some scientific organizations endorsed them.

Whoever wants to organize a march, protest, etc., is free to organize. This belongs to citizens’ rights, I think. But it is not a scientific action.

Therefore, I believe the term March for Science is detrimental for science. Equally detrimental is another recently promoted term, Citizen Science. It mixes up two very important notions, Citizenship and Science and, by doing so, it devalues both.

E. Schaffer
March 23, 2021 6:37 am

Water is the key indeed, just not in the way the paper suggests. I have written this article to outline the fundamental problem.

By now however I believe I made a mistake. Of course I double checked my results using Fresnel equations with those from other sources, like that below. They perfectly matched. Only now I discovered that although they do match with regard to short wave radiation, they do not with LWIR. I guess this is because I did not allow for the extinction coefficient, which is only negligible with SWR.

Re-doing the calculations with the necessary corrections, emissivity of water drops from 0.934 to only 0.908, while absorptivity (the extinction coefficient is negligible there) still remains at 0.934. Notably 0.908 coincides with the text book emissivity of 0.91, which is even found on german wikipedia.

The temperature water takes on with a given amount insolation thus is even higher than that of a perfect black body.

((0.934 / 0.908) * 342 / 5.67e-8) ^ 0.25 = 280.7K

That reduces the GHE even further, to only ~8K in size. At this point it is even questionable if GHGs cause a GHE at all. Also one should consider, that a surface at 288K and an emissivity of 0.908 will emit only 364W/m2 (not 390, nor 397)!

Reply to  E. Schaffer
March 23, 2021 12:05 pm

Thank you for this information, which however does not seem to justify your statement “Water is the key indeed, just not in the way the paper suggests”. Do you imply that the only role of water is about emissivity and that this restriction of its role (in comparison to a variety of roles that my paper suggests) better justifies why “Water is the key indeed”?

E. Schaffer
Reply to  Demetris Koutsoyiannis
March 23, 2021 7:56 pm

What I imply is, that we need to build from bottom up. Starting with the roof is no good idea. All speculation on climate trends and its causes, while not having understood what we call the “GHE”, is beyond reasonable. I know, most people do believe that part of the science was “settled”. Nothing could be further from the truth!

David L. Hagen
Reply to  E. Schaffer
March 23, 2021 5:28 pm

E. Schaffer If you wish to quantitatively model water vapor vs other green house gases, I recommend building on Ferenc Miskolczi’s work. e.g. Miskolczi, F.M., 2014. The greenhouse effect and the infrared radiative structure of the Earth’s Atmosphere. Development in Earth Science2, pp.31-52. He models 11 absorbing as species including H2O & CO2, at each of 3490 spectral intervals, with 150 vertical atmospheric shells, with fifth order gaussian model.

navy bob
March 23, 2021 6:44 am

When is the FBI going to arrest Dr. Koutsoyiannis and charge him with sedition?

Kevin kilty
Reply to  navy bob
March 24, 2021 7:16 am

Sarcasm rarely comes across accurately in these threads.

Eric H.
March 23, 2021 7:39 am

“Actually, one of the aims of the paper is to show that polarization stems from political, rather than scientific, roots.”
I’ve been saying this for years.

Robert of Texas
March 23, 2021 11:09 am

To understand how humans affect climate (if at all) one would have to be able to describe natural climate change – that is how climate would change absent of humans. No one can do this yet, and I suspect ever will.

Natural climate change should have short term modifiers removed from it as they just complicate the picture, so including the influence of volcanic eruptions should be removed unless they are demonstrated to occur with enough frequency to be a permanent fixture of the climate area studied. They can usually be treated as random unpredictable blips that correct themselves over a few years (unless somewhere like Yellowstone erupts).

This only leaves solar output (in all the various bands of light which can interact differently), distance from the Sun, the tilt of the axis, the strength of Earth’s magnetic field, the arrangement of the continents, the movement of various ocean currents, the amount of cosmic radiation into the atmosphere, the amount of snow cover, the extent of the glaciers, and a few other minor systems to understand and measure over a great deal of time.

One of the many elephants in the room is if the natural climate system is shown to be chaotic in behavior…If it is, we can never model with any certainty the Natural Climate System.

Another elephant in the room is the state of Climate Science. Since it is allowed to just change data at will, make up statistical nonsense to analyze the data, and make future predictions that never happen without any need to change their hypothesis, it will never be up to the task of actually forwarding scientific progress in explaining climate. It might as well be relabeled to Climate-VooDoo.

John Robertson
March 23, 2021 11:17 am

Good article.
Same here, as in been saying same thing for years.

Climate Change as meaningless as water wet.

And if the Cult of Climatology had to use defined terms,as is normal in scientific enquiry,they would fade away.

The very looseness of terminology used in Global Warming and Climate Change is all they have.
Means this is pure politics.

Well that and the open admission,by Team IPCC, that the Computed Models of Gospel,cannot model water in all its forms,yet are the defined “The Science” of doom by weather..On a world dominated by and blessed with Water.

Once I believed you could not make this kind of idiocy up.Carbon based life forms calling the stuff of life “Pollution”.Truth really is stranger than fiction.

Hurricane Willy
March 24, 2021 5:50 am

The IPCC claim in their first report 1990, that CO2 is a dangerous greenhouse gas because it absorbs and emits IR @ 15µm.  According to Wien’s displacement law 15µm has corresponding temperature of -80° C.  The troposphere, that’s the part of the atmosphere that we live in, is defined by molecules with a temperature of -60° C and above. Emissions of IR @ 15µm from CO2, cannot heat any molecules in the troposphere

Kevin kilty
March 24, 2021 7:22 am

An interesting observation from reading Prof. Koutsoyiannis’s paper is that the definitions of climate follow the basic definition of random variable, i.e. central tendency and dispersion at a minimum, but people tend to disregard the dispersion that randomness displays. People do this routinely in practically every quantity they encounter that displays randomness — such as human capabilities, market behavior, and so forth.

Kevin kilty
March 24, 2021 8:30 am

Gosh this paper contains some wonderful insights …

Is there anything special about 30 years? It appears that this reflects a historical belief that 30 years are enough to smooth out random weather components and establish a constant mean. In turn, this reflects a perception of a constant climate, and a hope that 30 years would be enough for a climatic quantity to stabilize to a constant value. It can be conjectured that the number 30 stems from the central limit theorem and in particular the common (but not quite right) belief that the sampling distribution of the mean is normal for sample sizes over 30 (e.g., [23]). Such a perception roughly harmonizes with classical statistics of independent events

I have taught a dozen or more courses in statistics, including engineering statistics where we wonder explicitly about applying the Z or t distribution to small samples for things like statistical process control, yet I had not thought about this.

Reply to  Kevin kilty
March 24, 2021 9:22 am

Thanks for the comment, Kevin. There is more about this and similar issues in my book, which will be in final form in a week or so. The book is cited in the paper–for convenience here is the link for the current form:

Stochastics of Hydroclimatic Extremes – A Cool Look at Risk,
(open access/creative commons licence)

March 24, 2021 6:22 pm

One aspect not mentioned is “global climate”.
Our current global climate is called an Icehouse climate.
Personally, I like to call it an Icebox climate** {which is used less often}.
Also called an Ice Age. Wiki:
An “icehouse Earth” is a period in which the Earth has at least two ice sheets, Arctic and Antarctic (on both poles); these sheets wax and wane throughout shorter times known as glacial periods (with other ice sheets in addition to the 2 polar ones) and interglacial periods (without). During an icehouse Earth, greenhouse gases tend to be less abundant, and temperatures tend to be cooler globally. The Earth is currently in an icehouse stage, that started 34 Ma with the ongoing Late Cenozoic Ice Age. “

** I like calling it icebox because icebox is another word for refrigerator, and Earth in it’s current configuration is like a refrigerator. The ocean is as cold as refrigerator, and Earth has mechanism of cooling- which colder water falls- and fills the world’s ocean basins.

AGW is Not Science
Reply to  gbaikie
March 26, 2021 10:34 am

During an icehouse Earth, greenhouse gases tend to be less abundant, and temperatures tend to be cooler globally.

Bullshit alert! Bullshit alert!

450mya, there was a full blown glaciation with 10x the current atmospheric CO2 level. The earth’s temperature has shown to be indifferent to the CO2 level on longer time scales, and the driver OF the CO2 level at shorter time scales.

Their mention of “greenhouse gases” is just another way to pimp the AGW propaganda, by “suggesting” that higher “greenhouse gas” levels “drive” the temperature, when the reverse is ture – it is the temperature that “drives” so-called “greenhouse gas” levels.

But then one must expect as much from Wikipropaganda…

March 25, 2021 12:52 am

The final version (pdf, html, etc.) with corrections of some typos is now online at the same site:

March 25, 2021 11:05 am

water is the main element that drives climate, and not the opposite.

The climate of Earth IS water, in all it’s states, and how they interact.
Sadly, despite all the claims about “basis physics” the basic physics we cannot model is just about every stage of the water cycle which defines our climate.

Exactly how, in mathematical terms, the pseudo-chrystaline surface of sea water evaporates, how much aerosol is created by specific conditions of wind and swell, exactly how advection can be formulated, how to model emergent phenomena like tropical thunderstorms, cloud formation and the precise nature and quantity of precipitation are far from a detailed mathematical description of the “basic physics”.

Even if we have a fairly good description of optical properties of the atmosphere, it is the weakest not the strongest link which determines the strength of a chain.

We cannot even measure certain quantities like cloud “amount” to within the accuracy we need to even know whether AGW is detectable behind natural changes.

The very term cloud “amount” reflects the problem that we can not even define what we are supposed to be measuring, so we call it “amount”.

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