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« Did the IPCC just blink? | Main | David Kennedy on climate sensitivity »
Thursday
Jul182013

Chalk up another for low climate sensitivity

Nicola Scafetta has a new paper in Energy and Environment, which finds a figure for climate sensitivity of 1.35, some what lower than even the torrent of EBM papers over the last year or two.

Global surface temperature records (e.g. HadCRUT4) since 1850 are characterized by climatic oscillations synchronous with specific solar, planetary and lunar harmonics superimposed on a background warming modulation. The latter is related to a long millennial solar oscillation and to changes in the chemical composition of the atmosphere (e.g. aerosol and greenhouse gases). How- ever, current general circulation climate models, e.g. the CMIP5 GCMs, to be used in the AR5 IPCC Report in 2013, fail to reconstruct the observed climatic oscillations. As an alternate, an empirical model is proposed that uses: (1) a specific set of decadal, multidecadal, secular and millennial astronomic harmonics to simulate the observed climatic oscillations; (2) a 0.45 attenuation of the GCM ensemble mean simulations to model the anthropogenic and volcano forcing effects. The proposed empirical model outperforms the GCMs by better hind-casting the observed 1850-2012 climatic patterns. It is found that: (1) about 50-60% of the warming observed since 1850 and since 1970 was induced by natural oscillations likely resulting from harmonic astronomical forcings that are not yet included in the GCMs; (2) a 2000-2040 approximately steady projected temperature; (3) a 2000-2100 projected warming ranging between 0.3°C and 1.6°C , which is significantly lower than the IPCC GCM ensemble mean projected warming of 1.1°C to 4.1°C; (4) an equilibrium climate sensitivity to CO2 doubling centered in 1.35°C and varying between 0.9°C and 2.0°C .

There is a preprint here. No doubt there will be the usual barrage of comments arguing that it should be ignored because it's in Energy and Environment. Let us see what a critique based on logic turns up.

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    - Bishop Hill blog - Chalk up another for low climate sensitivity

Reader Comments (53)

Forgive me but didn't Lindzen calculate a figure of 1.2 many years ago.

Jul 18, 2013 at 11:57 AM | Unregistered CommenterBrianJay

...a new paper in Energy and Environment, which finds a figure for climate sensitivity of 1.35, some what lower than even the torrent of EBM papers over the last year or two....


Climatic Progress

... the figure MUST be greater than 4...

... the IPCC specify a figure of 3....

... latest estimates suggest a figure of around 2....

... It looks as if the figure must be equal to 1...

... Since it is obvious that the Earth has a powerful thermostatic system for maintaining temperatures within a narrow band, there is effectively NO change in average climate temperature for the typical changes in radiative forcings that we experience...

Jul 18, 2013 at 12:09 PM | Unregistered CommenterDodgy Geezer

Forgive me...its just another model.

Get back to me when you can explain how an increase in CO2 in the atmosphere ,since 1850, of approximately .00004% can account for between 40 to 50% of the increase in the earths temperature.

Jul 18, 2013 at 12:21 PM | Unregistered Commenterconfused

Clarification,

the .00004% figure is the amount added by humans and not the total amount from Ocean out-gassing etc.

Jul 18, 2013 at 12:23 PM | Unregistered Commenterconfused

Jul 18, 2013 at 12:09 PM | Unregistered Commenter Dodgy Geezer

I agree Dodgy. it looks like 1.0 to me. Otherwise we would have boiled - or the earth would be a permanent iceball -already.

Jul 18, 2013 at 12:51 PM | Unregistered CommenterJimmy Haigh.

The two key battlegrounds in the scientific argument are sensitivity and feedback.

Even the Greenshirts are having to accept a sensitivity below 2C (per DOUBLING of CO2, let's not forget... as if 800ppm is in sight any century soon).

I do hope that sceptics will begin to challenge the feedback issue: The past several billion years of life on Earth demonstrates a process of stable equilibrium; of self-correction. Thermodynamics is but one such process, where hot things tend to cool down. Al Gore's brilliant adoption of the term "tipping point" has launched the unstable-equilibrium meme into the language. Brilliant but wicked, misleading, flat wrong. Tipping point mes fesses.

Jul 18, 2013 at 12:53 PM | Unregistered CommenterBrent Hargreaves

A proper Venus/Earth temperatures comparison (my small, yet definitive and seminal, contribution to climate science) shows that the only thing that affects the global mean temperature is variation in that portion of the incident solar radiation that is directly absorbed by the Earth's troposphere, because said direct absorption is the only way the troposphere is warmed, globally--heat from the unevenly heated surface can only drive the winds and weather, which constitute local and transient variations in the equilibrium vertical temperature structure of the troposphere (accurately given in the Standard Atmosphere model, known for over a century and precisely confirmed by the Venus/Earth comparison). The thermostat of our world is basically set by our mean distance from the Sun (our orbit is almost circular, so the solar distance is practically constant), and nothing else; that is the only "radiative forcing" affecting global mean surface temperature. Mr. Scafetta does not know any more about the truth of the atmosphere I have just outlined, than do the alarmist consensus climate scientists and their legion of meek followers, both alarmist and "lukewarm" (the latter including both Scafetta and our host here). My current response to the believers is "Don't Tell The Experts" (how simple it is to see the truth), and to those they want to tyrannize, "The System Is Broken", and it's much worse than anyone in authority (and responsibility), or even anyone with a large audience, will admit.

Jul 18, 2013 at 1:07 PM | Unregistered CommenterHarry Dale Huffman

Dodgy Geezer wos correct: the Earth has a powerful thermostat and it uses CO2 as the working fluid.......

The warming in the late 1980s and 1990s was from rapidly rising Asian aerosols causing clouds to have lower albedo.

Jul 18, 2013 at 1:10 PM | Unregistered CommenterAlecM

@Brent Hargreaves, it's not PER doubling, it's for a SINGLE doubling from pre-industrial CO2 levels.

There is no reason to think that additional doublings of CO2 concentration cause the same temperature rise, and every reason to think that they can not, as saturation is reached where the atmosphere becomes essentially opaque to infrared radiation. At that point, more opaque is meaningless.

Some think this has already happened.

Jul 18, 2013 at 1:14 PM | Unregistered CommenterBruce Hoult

I've been dismissing the concept of climate sensitivity as a useful thing for a long time over many posts. To avoid thread-bombing there is a discussion post entitled 'sense and sensitivity' which I plan to bump again. All I am looking for is someone who is willing to defend the concept of CS as a useful concept applicalbe over global areas and millennial timescales. No-one has ever done so. It is easy for people like Scafetta or Lewis to take the concept and set limits to its magnitude using models, history, empirical guesses at known unknowns and such, but all that presumes something not in evidence.

I don't think we should ever give the alarmists succour by accepting their concepts without question. To do it with CS is like the economists who say if we MUST have a climate tax this is how it should be run.


Give them nothing, make them prove it all.

Follow ups to http://bishophill.squarespace.com/discussion/post/2063688

Jul 18, 2013 at 1:19 PM | Registered Commenterrhoda

1.35°C and therefore benign.

Jul 18, 2013 at 1:28 PM | Unregistered Commenterssat

rhoda, I think talking CS is more fighting them with their own sword. It's their figure which they used to scare us in the first place. They don't like it up em when we give them it back.

Jul 18, 2013 at 1:34 PM | Unregistered CommenterTheBigYinJames

In my personal opinion the person who has done the best work on climate feedback is Dr. Roy Spenser
here is a sample

http://www.drroyspencer.com/2010/05/strong-negative-feedback-from-the-latest-ceres-radiation-budget-measurements-over-the-global-oceans/

The feeling amongst objective climate scientists is the feedback is net slightly negative. The positive feedback assumed by the IPCC has never been found !

Jul 18, 2013 at 1:45 PM | Unregistered CommenterRoss Lea

Sorry I ment to address that to Brent Hargreaves. I am sure many of the rest of you know that already.

Jul 18, 2013 at 1:48 PM | Unregistered CommenterRoss Lea

@Jul 18, 2013 at 1:10 PM | AlecM

The warming in the late 1980s and 1990s was from rapidly rising Asian aerosols causing clouds to have lower albedo.
////////////////////////

Was there any real warming during this period?

As regards Climate Sensitivity until we can fully evaluate natural variation, every forcing that goes up to make its constituent parts and the upper and lower bounds of such, we cannot begin to assess Climate Sensitivity. The fact is pure and simple, we cannot presently seperate the signal of Climate Senistivity to CO2 from the noise of natural variation. Period.

Any cliams as to the level of Climate Sensitivity is just a guess. Presently, it is disengenuous to claim any level of knoweledge or certaintywith respect to Climate Sensitivity.

I am sceptical that there was any real warming (as opposed to perceived warming) since the Sat data does not suggest that there was any warming (apart from the heat released in and around the Super El Nino of 1998).

The other temperature records are so basterdised throungh endless adjustments, polluted by UHI, poor station siting and station drop outs that one cannot have any real confdence in those records.

Jul 18, 2013 at 1:52 PM | Unregistered Commenterrichard verney

Who cares about theoretical sensitivity and forcing? It's quite obvious that the Earth's thermostat takes much greater changes in its stride and keeps the temperature at a reasonable figure .

This whole scare is based on the idea that the ONLY way the Earth cools is as a radiative black body, so any increase in temperature produces a new higher equilibrium. But that's not true - increases in cloud albedo and thunderstorms simply shift any excess heat up to the stratosphere and out into space more rapidly...

Jul 18, 2013 at 2:03 PM | Unregistered CommenterDodgy Geezer

My above post got a little out of sync.

The 2nd and 3rd paragraphs should be the 4th and 5th paragraphs.

So should be read paras 1, 4, 5, 2 & 3.

I agree with rhoda that we should not be giving time of day to Climate Sensitivity.

If people wish to raise Climate Sensitivity, the natural response is: 'then explain (i) why temperatures fell post 1940s just as CO2 levels began to rise substantially, and (ii) explain the temperature hiatus these past 16 to 22 years (depending upon temperature data set used).'

Jul 18, 2013 at 2:07 PM | Unregistered Commenterrichard verney

Could someone tell me if the following is correct?

Climate model builders in the late '90s and early '00s used historical data sets with big correlations between temperature and CO2. This caused them to build models that had high "climate sensitivity". Because the systems were more chaotic and complicated than the models, the models were/are misspecified.

Now adding in the last decade of data to the misspecified models, their "climate sensitivity" estimates are coming down to reflect the poor correlation of temperature and CO2 over the last decade.

It seems to me that these changing estimates are an artifact of recent history (a short time by geological perspective) and a concession that the science is not "settled."

Is there something wrong with this reasoning?

Jul 18, 2013 at 2:20 PM | Unregistered CommenterLeon0112

Leon0112, I feel the problem is that the system is chaotic although bound and coupled by physical laws. One thing that has come out of research into chaotic systems by mathematicians is that they are stable but can shift in patterns through both external factors and internally.

My suspicion is that the derivative deterministic nature of "climate science" is merely scientists fooling themselves that the patterns they see can be explained through cause and effect. This puts me in a more esoteric position on climate.

Jul 18, 2013 at 2:40 PM | Unregistered CommenterLiT

It is my contention (supported by Lindzen and others Scientists I have contacted on this issue) that the whole CAGW hypothesis crashes completely if Climate sensitivity can be empirically established (and hence beyond argument) at 2degees(C) or less.
Thus all the carry on about Polar Bears, Polar ice, penguins, sea levels etc etc are at best peripheral issues in addressing CAGW. and are totally irrelevant the day Climate Sensitivity is accepted by all as having a value of <= 2.
It does seem that both theory and measurement are homing in a value at even less that 2 degC. and this fact together with its devastation of the CAGW hypothesis should be relentlessly driven home in all debates/comments on CAGW..
I mention this as Andrew in his answers to the Parliamentary Committee certainly put emphasis on Climate Sensitivity but did not stress(to me at least) the pivotal importance of this parameter in relegating the whole sorry saga of "Climate Change" to the dustbin.

Jul 18, 2013 at 2:55 PM | Unregistered CommenterLawrie Waller

In 1886, J. Willard Gibbs, in his 'Paradox' deduced that no single entity in a thermodynamic assembly remembers its history. To do otherwise would give an increase in entropy. This simple deduction showed that there can be no thermalisation of absorbed IR in the gas phase when the source temperature is greater than the thermodynamic temperature of the gas.

All thermalisation is at heterogeneities such as aerosols and Space. as the energy scatters under the gradient of its em energy >lte. There is no 'back radiation' which for 70 years has been the mistaken belief that a temperature measurement = energy flux. It isn't and no professional physicist or engineer taught correctly will accept this - go back to Maxwell's Equations for the proof.

In practice the operational emissivity of the Earth's surface is ~0.35 and most of the real IR energy goes to Space or to clouds directly. The reduction of real IR energy flux by clouds, higher sink temperature than Space, is misinterpreted by climate alchemy as 'back radiation'. There is no positive feedback because the models are a perpetual motion machine, the extra heating offset by exaggerated cloud albedo.

So, in the absence of any other factor, intrinsic climate sensitivity is ~1.2 K. However, there is more in that this result implicitly assumes no change in the spectral distribution of OLR in the non - CO2 region. There is change and the control system which includes adaptation of the atmosphere and life forms gives OLR = SW in, no CO2-AGW being possible

Sorry folks, move along there, nothing to see except in deserts where there will be some warming. And yes, it is being submitted for publication.

Jul 18, 2013 at 3:01 PM | Unregistered CommenterAlecM

I am in total agreement with Rhoda on this one and like her I have posted previously about my opinion on CS.
Many people on the blog jump up and down with joy when a new paper on climate sensitivity comes out that gives a low figure. However just like the alarmist claims, the new figure is based on models.
To give some credit to Scafetta he has tried to create a model based on observations not on theories but he still admits that we do not know all the "effects" that need to be included.
The current understanding of CO2 in the atmosphere makes it impossible for a climate sensitivity figure to exist for more than a day or two. As a Bruce Hoult pointed out; the CO2 effect is logarithmic and at some point the climate sensitivity figure becomes zero, I am one of those who believes this has already happened.

Jul 18, 2013 at 3:08 PM | Registered CommenterDung

All very interesting and possibly more interesting is why Nicola Scafetta is publishing with Energy and Environment, are other doors closing?

Jul 18, 2013 at 3:24 PM | Unregistered CommenterTim Spence

Dung, personally I don't know or care to speculate what the value is but as Lawrie Waller points out that below a certain level it doesn't matter what value it might be because the C is taken out of CAGW. If sensetivity is below 2ºC for a doubling of CO2, then it would be well into the next century before we get to 3ºC which we know the planet has experienced before in recent time frames so is more than survivable. If we still have a problem and manknd hasn't worked out a solution by then... tough.

To argue a zero value for sensetivity is a step too far for many. Far easier to use the 1.2ºC lab value and then be pleasantly surprised if it's too high. Why make the job of bringing the CAGW proponents back from the brink any harder than it needs to be?

Jul 18, 2013 at 3:30 PM | Unregistered CommenterTinyCO2

TinyCO2: all it needs to get zero CO2 climate sensitivity is for cloud area to increase. The Earth adapts as an organism with multiple pathways. The cloud area adjustment is needed to overcome the finite radiative impedance in the 'atmospheric window' as lower atmosphere heat radiates to Space.

That impedance is ~ 0.05 deg C for doubled [CO2].

Jul 18, 2013 at 3:44 PM | Unregistered CommenterAlecM

I was aware of this paper three days ago, but chose not to write about it. I have lost faith in Scaffeta, mainly due to his methods which aren't much better than the Barycentrism nuttiness I'm often asked to publish.

The fact that he came up with a CS value that we "like" with these methods is coincidence IMHO.

Jul 18, 2013 at 3:49 PM | Unregistered CommenterAnthony Watts

Welcome Anthony Watts ^.^

TinyCO2 writing what you think will achieve your desired result is my understanding of what the other side do. I say what I think is right based on the information I have but am quite willing to listen to new information.
Right now we are pumping huge amounts of CO2 into the atmosphere and the planet has not batted an eyelid. In its current state the planet has zero sensitivity to increased CO2.

Jul 18, 2013 at 4:02 PM | Registered CommenterDung

@Dung

"Right now we are pumping huge amounts of CO2 into the atmosphere and the planet has not batted an eyelid."

But we're not "pumping huge amounts". That's just alarmist hyperbole. We're adding very small amounts in comparison to natural sources.

Jul 18, 2013 at 4:41 PM | Unregistered CommenterTurning Tide

Turning Tide

Yes perhaps I would have made the point better if I had said "We are told we are pumping huge amounts of CO2 into the atmosphere and the planet has not batted an eyelid".

Jul 18, 2013 at 4:48 PM | Registered CommenterDung

So some folks want to go along with the concept in order to rub the enemy's nose in the low numbers (however deduced?) but nobody is willing to defend the concept per se. Where did it come from? How did it become an accepted thing, and on what justification? Where did the estimates of its magnitude come from?

I don't know what this debate is about, but it ain't science.

Jul 18, 2013 at 4:49 PM | Unregistered Commenterrhoda

As Montford said, there are no academic sceptics in Britain. To me it looks like a 100% wall of silence vs a bunch of off the scale right wing nutters validating the science which is basically nonsense. One has to wonder whether Montford has read his own books.

In one of the bloodiest scenes in the history of cyberspace, the Guardian opened a discussion on the basics of climate science. Something like 90% of the mathematically literate posters said the idea of computers modelling the earth's climate was preposterous. The Guardian deleted their messages and banned them.

The Guardian - big business for dummies.

Jul 18, 2013 at 4:53 PM | Unregistered CommentereSmiff

rhoda: 1981_Hansen_etal.pdf adapted Manabe and Stirckland's work who assumed SW down = LW IR up, gross exaggeration, not bad science.

GISS claimed removing ghgs would reduce surface temperature to the same virtual -18 deg C for present OLR. No clouds or ice means no albedo from these sources; the real equilibrium temperature is for 341 W/m^2 not 238.5 W/m^2; 4-5 deg C. Real GHE ~11 K; 33/11 ratio is the imaginary positive feedback.

The rest of the game involved finessing the models to purport correct numbers. This was done by assuming 'back radiation', offsetting it by assuming Kirchhoff's Law of Radiation applies at ToA. This creates 6.85x real 23 W/m^2 thermalised in the atmosphere. It is offset by ~double real low level cloud optical depth to purport correct temperature.

Because the sunlit ocean is 'warmer' and evaporation kinetics at constant RH are proportional to exp(sea temperature), more H2O appears, the imaginary cause of the imaginary positive feedback. One justification is to claim pyrgeometers output a real energy flux; actually potential flux to a sink at 0 deg K. The other has been to fiddle past land temperature data and hockey sticks.

That 97% of climate scientists believe this indicates the stupid gene has left just 3% unscathed....

Jul 18, 2013 at 5:33 PM | Unregistered CommenterAlecM

"about 50-60% of the warming observed since 1850 and since 1970 was induced by natural oscillations likely resulting from harmonic astronomical forcings that are not yet included in the GCMs"

No one picked this up. I assume they mean cosmic rays. NASA and CERN (Kirkby) have both come to understand, they are the likely real climate drivers.

NASA


There is, however, a dawning realization among researchers that even these apparently tiny variations can have a significant effect on terrestrial climate. A new report issued by the National Research Council (NRC), "The Effects of Solar Variability on Earth's Climate," lays out some of the surprisingly complex ways that solar activity can make itself felt on our planet.

http://science.nasa.gov/science-news/science-at-nasa/2013/08jan_sunclimate/


CERN 'gags' physicists in cosmic ray climate experiment

The chief of the world's leading physics lab at CERN in Geneva has prohibited scientists from drawing conclusions from a major experiment. The CLOUD ("Cosmics Leaving Outdoor Droplets") experiment examines the role that energetic particles from deep space play in cloud formation. CLOUD uses CERN's proton synchrotron to examine nucleation.
CERN Director General Rolf-Dieter Heuer told Welt Online that the scientists should refrain from drawing conclusions from the latest experiment.

"I have asked the colleagues to present the results clearly, but not to interpret them," 

http://www.theregister.co.uk/2011/07/18/cern_cosmic_ray_gag/

Jul 18, 2013 at 6:38 PM | Unregistered CommentereSmiff

Smiffy

I think they are talking about Milankovitch cycles and the like.

Jul 18, 2013 at 6:44 PM | Registered CommenterDung

Thank you for posting.

I read the comments of the readers which I thank of course.

An impression that I had is that many readers have not read the paper first, at most they skipped it. I would like to invite the interested readers to read it. The paper is quite long and contains numerous arguments in an attempt to address numerous issues and make them to fit a comprehensive figure which I believe that it is quite convincing at the end.

I would like to respond explicitly to Anthony Watts that says "I was aware of this paper three days ago, but chose not to write about it. I have lost faith in Scaffeta, mainly due to his methods which aren't much better than the Barycentrism nuttiness I'm often asked to publish. The fact that he came up with a CS value that we "like" with these methods is coincidence IMHO."

it is evident that Anthony did not read the paper. See Anthony, in science people are not required to have "faith" in somebody. Science is different from "religion" because it is based on a scientific method that is based on specific rules that people can check by themselves if they so wish.

Your lack of "faith" is unfortunately based on a severe misunderstanding of the science addressed in my paper and of astrophysical knowledge in general.

In fact, your sole argument is that in your opinion the "mechanism" is non physical. You are talking about "Barycentrism nuttiness". Your argument is that the Sun is in free fall in its barycentric movement and as it is well known a body in free fall does not feel the effects of gravity moving it.

As I have tried in vain to explain to you, I fully agree with your objection.

However, you have not tried to fully understand my argument which is based on two different mechanisms.

1) When I talk about gravity I never refer to the barycentric movement as a physical cause, at most as a proxy. As the physical cause I am referring to tidal forcings which are physical unless you deny them about the ocean.

In the case of the Sun, the tidal forcing from the planets are weak as well known, but as I propose in one of me papers there might be the possibility of a nuclear fusion amplification feedback from the sun. This is explained here:

Scafetta N., 2012. Does the Sun work as a nuclear fusion amplifier of planetary tidal forcing? A proposal for a physical mechanism based on the mass-luminosity relation. Journal of Atmospheric and Solar-Terrestrial Physics 81-82, 27-40.

This mechanism would cause a modulation of solar activity that would present the major harmonic of the climate system such as the quasi 10-12-year cycles, the 60-year cycle, the 115-year cycle and the millennial cycle, and other minor cycles that are also found in the climate system for 10,000 years. Study well my second paper:

Scafetta N., 2012. Multi-scale harmonic model for solar and climate cyclical variation throughout the Holocene based on Jupiter-Saturn tidal frequencies plus the 11-year solar dynamo cycle. Journal of Atmospheric and Solar-Terrestrial Physics 80, 296-311.

2) I also talk about a different mechanism which is more related to the barycentric movement of the sun, in particular its speed. However, in this case I am not talking about gravitational forcings but about electromagnetic forcings. While gravitational forcings do not matter in the barycentric movement, as you correctly know, electromagnetic forcings do matter because directly related to the relative speed of the Sun relative to the planets and to the galaxy. These forcings surely influence the electromagnetic properties of the heliosphere, which may influence the space weather and the climate of the earth. For example, a quasi 20-year cycle is expected from this mechanism.


3) Finally I also talk about specific soli-lunal tidal cycles modulating the ocean circulation such as the quasi 9.1 year oscillation, that is more easy to understand once that you understand the movement of the moon.

Thus, your "lack of faith" appears to me based on a poor understanding of astrophysics that does not get yet the three points above.

However, by starting from your false premise (that is your erroneous conviction that I am ignoring that the sun is in free fall in its movement and that that is the only way to understand the phenomenon neglecting tidal and electromagnetic forcings) you construct a straw man argument concluding that the results must coincidental.

Indeed, you are not able to demonstrate the "coincidence" claim.

In science when a model fits the data better than other models and it is further tested on its hindcast ability as I show in my case, people may need also to try to address the possibility that their "objections," like yours for example, are based on baseless "prejudices", as I am trying to explain to you.

So, I hope that you reconsider your position by letting a discussion to develop also on your web-site for the benefit of your readers. After all, these issues related on climate changes are complex and nobody has a definitive answer. So, you can not exclude that the solution might be somehow "surprising" for somebody. and after all you are not disproving my results, don't you?

Jul 18, 2013 at 6:49 PM | Unregistered CommenterNicola Scafetta

I have always had doubts about the positive feedback from more water vapour resulting from warming. I believe that water, with its phase change abilities within our climate temperature range, together with its considerable latent heats associated with these changes, plays an important role in earth's thermostat function. Further more, it can help transport energy around our planet in the atmosphere as well as in the oceans.

The alleged positive feedback of water vapour doesn't need CO2 GHG warming to kick it off. Any source of heat that produces more evaporation should be able to do it, for example whatever caused the MWP.
The earth has been hotter than today many times in its history and I'm not aware of any evidence that water vapour showed strong positive feedback. I'm beginning to suspect that the GHG effect becomes practically insignificant in the real world where convection and other factors intervene.

One of the depressing things about climate science is that policy decisions are based on crackpot models that were created with incorrect assumptions. That is surely beyond dispute, though the culprits do not admit it. Of course, models of poorly understood systems should never be taken seriously.

Models are extremely useful for exploring "what if?" questions and I suspect that in climate science this open minded scientific approach has been abandoned in the current culture where the science is settled and the true believers will not budge one bit from their rigid belief system. Such a waste.

Jul 18, 2013 at 7:14 PM | Unregistered CommenterSchrodinger's Cat

Jul 18, 2013 at 12:09 PM | Dodgy Geezer

Climatic Progress

... the figure MUST be greater than 4...

... the IPCC specify a figure of 3....

... latest estimates suggest a figure of around 2....

... It looks as if the figure must be equal to 1...


If all the estimates had come from the same source it would look rather like a Dutch auction!

Jul 18, 2013 at 7:24 PM | Unregistered CommenterRoy

As an alternate, an empirical model is proposed that uses: (1) a specific set of decadal, multidecadal, secular and millennial astronomic harmonics to simulate the observed climatic oscillations; (2) a 0.45 attenuation of the GCM ensemble mean simulations to model the anthropogenic and volcano forcing effects. The proposed empirical model outperforms the GCMs by better hind-casting the observed 1850-2012 climatic patterns.

Well obviously it will outperform them. My Lotus 1-2-3 spreadsheet can hind-cast even better in fact it hind-casts with complete accuracy.

Testing on the training data leads to the delusion that the model has 'skill'.

But in any case, unvalidated sensitivity models, built on unvalidated GM models, built on unvalidated radiative forcing models gives what? [clue: the answer contains the following letters: R-BB-SH]

Jul 18, 2013 at 7:29 PM | Registered CommenterMartin A

Sounds like Spencer and Braswell will shortly be adding another estimate to the list on the low side - 1.3.

Jul 18, 2013 at 7:33 PM | Registered CommenterPhilip Richens

Dear Martin,

try to read the paper before criticizing it.

The harmonics are not really based on the training data.

For example, the phases and frequencies of all harmonics are fully consistent with astronomically deduced astronomical harmonics within very small time lag (at most) that would be consistent with theoretical predictions - thermal inertia and so on.

The amplitude of the millennial cycle is trained on the period 1000-1700, well before the 1850. etc.

Look carefully at the figures.

The model is based on the same philosophy used in the tidal ocean models.

So, the fact that at the end the things fit together are not so "obvious" as you think.

Tests have been conducted in in other referenced papers by calibrating on the 1850-1950 year period and hidcasting the 1950-2010 year period and viceversa. Hindcast tests go back millennia.

Jul 18, 2013 at 8:10 PM | Unregistered CommenterNicola Scafetta

Nicola - OK I promise I'll read it.

Jul 18, 2013 at 8:11 PM | Registered CommenterMartin A

I read the first five pages completely, half read another ten pages and then scanned the rest. I was put off by the space wasted on stating what we already know, rather than getting to the meat of Scafetta's arguments, I will attempt to finish reading it.
However it is still true that Scafetta admits that we do not know all the effects that need to be modelled and so it is impossible to know if his model is of any use.

Jul 18, 2013 at 8:45 PM | Registered CommenterDung

Leon0112 Jul 18, 2013 at 2:20 PM saith:
***
Is there something wrong with this reasoning?

***

Yes and then again no. There is, over geological spans a correlation between CO2 and temperature, but, the correlation is reversed. Atmospheric CO2 lags temperature throughout the last half-million years. That is, temperature increases precede increases in atmospheric CO2. The lag is variously estimated but seems to be at least several centuries, meaning the current increases in CO2 might in fact be due to the Medieval Warming, or if the lag is in fact somewhat shorter than estimated, the current increase is simply due to the end of the LIA.

One fact that is rarely addressed in detail is that human contributions to atmospheric CO2 constitute a minute - as in nearly nonexistent - portion of the global out-gassing of CO2. Because we lean on fossil and thus "dead" carbon, our efforts do shift, very slightly, the available balances of the various carbon isotopes, but there is little if any empirical support for the idea that our contributions are actually swamping environmental carbon uptake mechanisms (green plants making sugars basically). At least one recent paper suggests that at worst, our contribution is encouraging a greening of desert regions observable in satellite imagery. This should not even be a surprise. Increases in available CO2 for plants should result in more efficient use of water by plants as they take in water to produce carbohydrates. Because of the increased CO2 available, the plants leaves can reduce the number and size of stomata, thus resulting in less water loss through respiration. In fact, there might even be a net increase over time of of available ground water since the plants also need less water to refrain from wilting as well.

Jul 18, 2013 at 10:49 PM | Unregistered CommenterDuster

Spot on Mr Duster ^.^

Jul 19, 2013 at 12:36 AM | Registered CommenterDung

Nicola Scafetta,
(1) Your assumption of a quadratic secular trend is not only unjustified but unjustifiable. It is also unnecessary, since a moving average over a long enough period (with end-padding for additional data) will do the job without this assumption.
(2) You suggest that the quasi 61-year cycle in the temperature record can be explained as a beat frequency of two high frequency oscillations. This might be true if the observed frequency in the data was an amplitude modulation, but it isn't. It is a mean-changing phenomenon not a variance-changing phenomenon. The existence of these high f data is not an issue. Can they explain the 61 -year cycle? Apparently not.
(3) I am at a loss therefore to see what your paper adds to many others that have noted the frequency content in the temperature series. I don't doubt the frequency content. I do doubt your explanation for their presence.

Jul 19, 2013 at 12:36 AM | Unregistered CommenterPaul_K

Dear Paul_K

as I said before it is a good idea to read a paper before criticizing it.

1) I do not make any quadratic secular trend assumption in the paper.

2) Your argument based on the difference between "mean-changing" phenomenon and a "variance-changing" phenomenon is not valid because you are interpreting the phenomenon as a perfectly linear one, instead of a non linear one. The argument that I made is that there are nonlinear phenomena where the positive aspect of the theoretical modulating curve is stressed relative to the negative one.
Indeed, the quasi-60 year modulation is also present in the speed of the sun and here it is a "mean-changing" phenomenon that would couple to the other beat frequency and other mechanisms can stress the positive active part of the theoretical curve. Look at both figure 7A and 7B and the proposed model in figure 13. And consider that non=linear effects would also stress low frequencies.

3) therefore, your being "at loss" may be simply due to poor reading of the paper. You may also need to read the references.

In any case, what matter here is the existence of specific temperature frequencies that are found in astronomical records, which you do not doubt. A detailed physical explanation of the microscopic mechanisms is not the topic of the paper.

Jul 19, 2013 at 3:14 AM | Unregistered CommenterNicola Scafetta

Nicola,
I agree, posters should read the paper. It is actual science as opposed to what we are frequently exposed to.

Whether or not your hypothesis of solar nuclear amplification based on astronomical gravitation is true should be the subject of serious rebuttal and exploration. And I hope it is taken seriously by those who have the intellectual capacity to pursue it.

For me the empirical fact of close correlation of hindcasts compared to any other model is of itself worthy of review and exploration, and is intuitively plausible.

For these reasons, and since it is highly consistent with other researcher conclusions your contribution is convincing. I hope others will follow your lead.

Jul 19, 2013 at 5:23 AM | Unregistered CommenterNiff

"All very interesting and possibly more interesting is why Nicola Scafetta is publishing with Energy and Environment, are other doors closing" Yawn. First, other doors? What there are a lot of (ISI-indexed, peer-reviewed) journals which welcome unorthodox views on AGW? Second, presumably the guest editor of the special issue invited him. The guest editor, Rorsch, as I understand it (his editorial is open-access at http://multi-science.metapress.com/content/a147273257660688/?p=4c86ae7d55394f4cb1fbd3e955ba1523&pi=0 ) wants to provide policy makers with alternative explanations for the observed global warming, arguing that the IPCC advice to policy makers focusses on global warming as a function of man caused increase of CO2; limited advice leads to limited policy.

Jul 19, 2013 at 9:39 AM | Unregistered Commenterbill

Dear Dr Scafetta,

Let’s deal with the minor point first – your use (or not, as the case may be) of a quadratic trend to abstract the multidecadal cycles. You write:-

I do not make any quadratic secular trend assumption in the paper.

In your paper, on the other hand, you write:-
By detrending the long-term warming trend (Note#11) the quasi 61-year oscillation can be highlighted, as shown in Figure 5, where an almost perfect match between the 1880-1940 and 1940-2000 GST periods emerges.

Note#11 (and Figure 5 in your paper) then takes us to:-

Note#11 This is done with a quadratic function, which captures the observed warming acceleration and is as orthogonal as possible to the multidecadal oscillations observed in the data.

My contention is that the use of such quadratic trend is both unjustifiable and unnecessary for the abstraction of the multidecadal cycles from the instrumental series, or indeed for the characterisation of the long-term warming trend. There are at least two valid ways of unambiguously abstracting the long wavelength variation (long-term warming trend, if you prefer) without having to make unjustifiable assumptions about its functional form. I accept that, in this paper at least, you do not use the quadratic function for any predictive extrapolation outwith the instrumental series, which would lead to a far more serious error. I also accept that even if you did use a fitted quadratic form for the fitting of the multidecadal cycles (did you?), it does not introduce a large error in the definition of such multidecadal cycles. However, it is poor methodology, and just for the record, the quadratic is not “as orthogonal as possible”, although it may be so if one only considers the set of low-order polynomials. It might help if you were to actually clarify how you did obtain your empirically fitted parameters for the 61-year oscillation.

The far more serious question is whether you have made your case that the multidecadal cycles can be explained in terms of your astronomic inputs. While the presence of a beat frequency at around 61 years from the high frequency cycles (9.1 and 10.2 year periodicities) is interesting, it cannot affect the mean variation observed in the temperature series at 61 year periodicity. From your comment, we are agreed on this, I believe. In your response to me, you state:-

Indeed, the quasi-60 year modulation is also present in the speed of the sun and here it is a "mean-changing" phenomenon that would couple to the other beat frequency and other mechanisms can stress the positive active part of the theoretical curve.

If your postulate about a relationship is correct, you should be able to show that (a) the modulated amplitude of your speed of the sun series (after your scaling to temperature) is sufficient on its own to explain the mean variation of the filtered temperature series at 61-year periodicity and (b) the summation of your (scaled) speed of the sun input combined with your (scaled) high frequency cycle input yields series in both mean and variance which are compatible with these series in the instrumental dataset.

If I understand your paper correctly, you have not done the above at all. Instead, having pointed to the coincidence of a beat at 61 years from high frequency data and of a speed wobble with a small amplitude variation at about the same periodicity, when smoothed, you then disconnect entirely from your inputs and abstract the four dominant cycles by means of a Fourier analysis of the instrumental series! This can of course be done without any assumptions about the underlying reasons for the existence of these cycles in the data, as you are aware. While what you have done may indeed tell us something important about the high frequency cycles, it offers little to support the possibility of the 61 year cycle being explained by these inputs.

There again, I will be happy to be told that I am still misunderstanding the paper.

Jul 19, 2013 at 10:25 AM | Unregistered CommenterPaul_K

To Bill,

you are right. The paper was an invited contribution by guest editor, Rorsch, who explicitly asked me to summarize my research published on other peer-reviewed papers for more general readers. So, I write a kind of general review for general readers.

All papers of the E&E special edition are invited contributions and are extensively peer reviewed (50 professional reviewers also among IPCC advocates were used).

The purpose of the E&E collection was to provide policy makers with alternative explanations of climate changes than what they can find on the IPCC AR5 that will be published in the fall which is biased in advocating only the AGW side of the story.

Jul 19, 2013 at 11:38 AM | Unregistered CommenterNicola Scafetta

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