Via Roger Pielke Sr. climatescience blog:
At the December 2008 NRC meeting “Detection and Attribution of Solar Forcing on Climate” [see] there was extensive criticism by Gavin Schmidt and others on the research of Nicola Scafetta with respect to solar climate forcings. He was not, however, invited to that December meeting.
There is now a new paper that he has published that needs to be refuted or supported by other peer reviewed literature (rather than comments in a closed NRC meeting in which the presentors would not share their powerpoint talks).
The new paper is
Scafetta N., R. C. Willson (2009), ACRIM-gap and TSI trend issue resolved using a surface magnetic flux TSI proxy model, Geophys. Res. Lett., 36, L05701, doi:10.1029/2008GL036307.
The abstract reads
“The ACRIM-gap (1989.5-1991.75) continuity dilemma for satellite TSI observations is resolved by bridging the satellite TSI monitoring gap between ACRIM1 and ACRIM2 results with TSI derived from Krivova et al.’s (2007) proxy model based on variations of the surface distribution of solar magnetic flux. ‘Mixed’ versions of ACRIM and PMOD TSI composites are constructed with their composites’ original values except for the ACRIM gap, where Krivova modeled TSI is used to connect ACRIM1 and ACRIM2 results. Both ‘mixed’ composites demonstrate a significant TSI increase of 0.033%/decade between the solar activity minima of 1986 and 1996, comparable to the 0.037% found in the ACRIM composite. The finding supports the contention of Willson (1997) that the ERBS/ERBE results are flawed by uncorrected degradation during the ACRIM gap and refutes the Nimbus7/ERB ACRIM gap adjustment Fröhlich and Lean (1998) employed in constructing the PMOD.”
A key statement in the conclusion reads
“This finding has evident repercussions for climate change and solar physics. Increasing TSI between 1980 and 2000 could have contributed significantly to global warming during the last three decades [Scafetta and West, 2007, 2008]. Current climate models [Intergovernmental Panel on Climate Change, 2007] have assumed that the TSI did not vary significantly during the last 30 years and have therefore underestimated the solar contribution and overestimated the anthropogenic contribution to global warming.”
Interestingly, TSI has been on a slight downtrend in the past few years as we get closer to solar minimum. The graph below is from the ACRIM project page.
Click for a large image
It remains to be seen if we have hit the minimum yet.
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Nasif Nahle (09:49:01) :
What I know is that D is unpredictable and that it oscillates according to inner factors related with oceanic currents, gravity, electrodynamics,
Leif Svalgaard (11:21:49) :
which means that one cannot claim there is evidence for a connection if you don’t know the randomly varying delay.
Dear Leif,
Evidence consists of the correlation itself. Mechanisms of Earth’s system and breaks that causes D are what we don’t understand… yet. Nonetheless, the correlation is noticeable.
Stephen Wilde (11:52:36) :
I don’t think one should simply compare one solar cycle with another taking each in isolation.
I don’t think we are communicating. People claim an obvious correlation between solar activity and climate. All the other effects you mention would degrade that correlation severely, showing that either
1) these other effects are minor, or
2) the obvious correlation is spurious to begin with.
“DAV (11:52:41) :
Joel Shore (10:13:55) : That there is still considerable uncertainty, however, is demonstrated for example by the fairly wide range of climate sensitivity (2 to 4.5 C) for the doubling of CO2 that the IPCC considers to be likely values.
So what CO2/Temperature ratio would unequivocally disprove this 2C – 4C CO2 sensitivity claim? If CO2 rises but temperature decreases would that do it (IOW: NEGATIVE sensitivity)?”
DAV, of course that wouldn’t disprove it! I don’t think it can be disproved in their minds.
I too read both the Gerlich/Tscheuschner paper and the Smith paper. Understanding either paper requires multiple readings; and even then “holes” in understanding exist (at least in my understanding). However, weaknesses of the Smith paper are (a) its disregard of heat transfer from the surface of the earth to the atmosphere via convection and conduction, and (b) the resulting loss of thermal energy to space via radiation by that atmosphere. According to Gerlich/Tscheuschner, the Stefan-Boltzmann law doesn’t apply to gases. This makes sense to me if for no other reason than for a gas whose pressure changes with altitude, there is no “definable surface” at which to apply the Stefan-Boltzmann law. For a paper that purports to model energy leaving/impacting earth, to exclude the thermal radiation/absorption properties of an atmosphere is a major weakness.
When Smith’s paper argues that in the absence of IR-absorbing gases the earth would be at least 33 degrees cooler, he bases that argument on a radiation model where only the earth’s surface radiates energy that is lost to space. Such a model can’t be correct because all matter above zero degrees Kelvin radiates energy; and for an atmosphere surrounding a black body, some of that energy will escape into space. Since an atmosphere that surrounds a black body will via conduction and convection receive heat from the black body surface, to ignore such atmospheric convection/conduction transfer and the resulting radiation of energy into space by the atmosphere renders Smith’s model of the earth suspect.
I can envision several models for the earth’s loss of heat to space that I think are superior to Smith’s model. Unfortunately, I don’t have the knowledge to determine the temperature properties of those models–but I’d sure appreciate it if someone whose has such knowledge determined that temperature behavior. The simplest model is a spherical black body surface (thin shell whose radius is approximately equal to the earth’s radius, and whose mass is approximately equal to the earth’s mass) surrounded by a non-IR-absorbing ideal gas of constant mass comparable to the total mass of the earth’s atmosphere. For each square meter of the black body surface, thermal energy at a rate of approximately 342 Watts (the approximate power received from the sun averaged over the surface of the earth) is being generated. This energy (a) heats up the surface of the black body, which (b) via convection and conduction heats up the non-IR-absorbing ideal gas until the system comes to radiation equilibrium–i.e., until the total energy per unit time escaping into space equals the total energy per unit time generated at the black body’s surface. In addition to computing the temperature of the surface of the black body, such a model would include profiles (as a function of altitude above the surface of the black body) of (a) the density of the non-IR-absorbing ideal gas, and (b) the temperature of the non-IR-absorbing ideal gas.
By symmetry, once such a system achieves “radiative balance” (assuming radiative balance is possible), all heat transfer via convection away from the black body surface will have ceased. However, heat will still leave the surface of the black body via both radiation and conduction. Furthermore, the non-IR-absorbing ideal gas will radiate thermal energy, some of which will escape into space. In such a model, the thermal energy input at the surface of the black body can leave that surface via both radiation and conduction; and as such, I have to believe the temperature of the black body surface would be different in the absence/presence of the non-IR-absorbing ideal gas. It may be that in the presence of a non-IR-absorbing ideal gas the temperature of the surface of the black body would be lower than in the absence of the non-IR-absorbing ideal gas. If so, the argument that IR-absorbing-gases are responsible for the earth’s surface temperature being 33 or more degrees higher than in the absence of IR-absorbing-gases. However, if in the presence of a non-IR-absorbing ideal gas, the temperature of the surface of the black body is higher than in the absence of the non-IR-absorbing ideal gas, then the argument that the presence of IR-absorbing-gases keeps the surface of the black body surface 33 degrees higher than would be the case in the absence of all IR-absorbing-gases is weak.
Because, this post is probably too long as is, I’ll refrain at this time from describing more complex models which I believe are improvements to the model in Smith’s paper.
Best, Reed Coray
Paul Linsay (12:11:36) :
“1) TSI has not changed since then
2) TSI does not drive the climate significantly”
I don’t know enough to argue point 1, but point 2 is unknown since the earth’s climate is a nonlinear system, chaotic.
Yet people who claim there is strong evidence invariably show linear correlations. So, either those linear correlations are spurious to begin with or we cannot predict from solar influence what the climate outcome would be, or from any other set of data, e.g. CO2, orbital changes, etc.
Nasif Nahle (12:36:30) :
Evidence consists of the correlation itself. Mechanisms of Earth’s system and breaks that causes D are what we don’t understand… yet. Nonetheless, the correlation is noticeable.
If the correlation is noticeable, D is known [can be deduced from the correlation]. The way to do this is simple: you calculate the correlation coefficient between two time series at zero lag. Then you move over one time series one step [e.g. a year if it were a yearly series] and calculate the correlation coefficient again. You do this again with a log of 2, then of 3, etc. The lag where the coefficient is the greatest is the delay. So, if you notice the correlation, you tell me the lag.
Stephen Wilde (11:52:36):
And if that were the basis for TSI, then TSI for SC13 [a hundred years ago] would also be similar to TSI during the last decade, and if that in turn drives the temperature, then the temperature back then should also be similar to 1996-2008. So, two things:
1) TSI has not changed since then
2) TSI does not drive the climate significantly [and please – no silly comments about turning off the Sun
Dear Stephen,
Recent studies show that TSI drives the climate drastically:
Cowen, Ron. Stormy Weather – When the Sun’s Fury Maxes Out, Earth May Take a Hit. Science News. January 13, 2001. Vol. 159, Pp.26-28.
Perkins, Sid. Pinning Down the Sun – Climate Connection-Solar Influence Extends Beyond Warm, Sunny Days. Science News. January 20, 2001. Vol. 159, Pp. 45-47.
The authors of the investigations agree on D factor for explaining the negative correlations.
Small correction. The words I attributed to Stephen Wild actually were from Leif Svalgaard’s message. I apologize…
“Leif Svalgaard (12:39:01) :
Stephen Wilde (11:52:36) :
I don’t think one should simply compare one solar cycle with another taking each in isolation.
I don’t think we are communicating. People claim an obvious correlation between solar activity and climate. All the other effects you mention would degrade that correlation severely, showing that either
1) these other effects are minor, or
2) the obvious correlation is spurious to begin with.”
I see your point but of course factors that dilute a correlation do not deny the correlation as you seem to suggest.
The solar changes may be minor in the short term (a couple of solar cycles or even more) but they are large in human terms over a century or two and at any point the oceans can multiply them up or down by quite enough to yield a warming such as that observed from 1975 to 2000 without any need for an alternative cause.
You claimed that cycle 13 should result in similar temperatures to cycle 23. I explained why that claim is wrong.
Leif Svalgaard (05:55:36)
much better calibrated SORCE TSI]
The TIM instrument is yet to pass calibration as far as I am aware.It failed NIST verfication,Has this been Reebaluated
“Leif Svalgaard (11:46:05) :
Stephen Wilde (11:35:02) :
The small size of the solar variability is not important. The charts show that the climate is sensitive to it regardless and that variability is filtered through the oceans in a very variable manner but when one sees a 400 year chart the connection is obvious.
Reply from Leif:
On the 400-year time scale there are only a few degrees of freedom and obvious connections dwindle into statistical coincidence. You could also plot the population of North America and see the obvious connection with something being low in the 1600s and high in the 2000s. Now, real enthusiasts will go further and say the that reason is obvious: with more TSI, better agriculture, higher population, see?”
My reply:
Yes I do see but you are stretching credibility in this case. I do not accept that cooler climates coinciding with a less active sun are simply a statistical coincidence.
First you deny any significant correlation due to a less than perfect match. Then when I explain why the match cannot be perfect because of the oceanic effect you shift your case to a statistical point that has little merit when one can see that throughout 400 years the correlation has held in temperature movements up and down with rises and falls in sunspot numbers and we may be in the midst of another occasion now as warming of the globe stops just when solar activity declines and the oceans turn negative.
I take the view that ongoing events provide additional evidence but it seems that you have a fixed opinion which you are not prepared to review. Of course I cannot speculate as to why that may be so.
Basil (11:50:14) :
“Stephen Wilde (11:35:02) :
Stephen,
My gut says you are right…that the solar influence is being buffered and modulated by ocean dynamics. But coming up with a convincing demonstration of the relationship is no mean feat.
Basil”
Thanks Basil, and of course the matter of a convincing demonstration is indeed the key. Earlier technology is not up to collecting the relevant data.
I’m confident that modern techniques are up to it and I just have to wait and see what transpires over the next 5 to 10 years.
Hopefully I will prove that an experienced and well informed human brain is better at pattern recognition than a computer model.
Basil,
Not only are the solar variations being modulated and buffered by ocean cycles but additionally the ocean cycles are being modulated and buffered by air circulation and weather systems.
My best guess as to how it all interacts can be found here:
http://climaterealists.com/attachments/database/Balancing%20the%20Earths%20Energy%20Budget__0__0__1233774754.pdf
Leif Svalgaard (12:39:01) :
1) these effects are minor,
2) the obvious correlation is spurious to begin with.
This climate discussion appears to be far more interesting than I assumed.
An interesting hobby for a retired engineer ?
Stephen Wilde (13:40:04):
Not only are the solar variations being modulated and buffered by ocean cycles but additionally the ocean cycles are being modulated and buffered by air circulation and weather systems.
I agree; besides, there are other factors which could influence the TSI effects on Earth’s climate; EMF oscillations and ICR, for example. I’m almost sure we’ll find the mechanisms soon.
Leif; did the temperature 100 years ago in SC 13 start from the same base? If the starting point was different there would be no reason to expect the end point ot be the same. Just asking.
“Leif Svalgaard (12:46:51) :
Nasif Nahle (12:36:30) :
Evidence consists of the correlation itself. Mechanisms of Earth’s system and breaks that causes D are what we don’t understand… yet. Nonetheless, the correlation is noticeable.
If the correlation is noticeable, D is known [can be deduced from the correlation]. The way to do this is simple: you calculate the correlation coefficient between two time series at zero lag. Then you move over one time series one step [e.g. a year if it were a yearly series] and calculate the correlation coefficient again. You do this again with a log of 2, then of 3, etc. The lag where the coefficient is the greatest is the delay. So, if you notice the correlation, you tell me the lag.”
How can one apply that when the lag is highly variable as in my oceanic scenario ?
In other words a correlation can be noticeable and true but extremely difficult to verify statistically but relatively easy to verify on a simple graph plotted over enough time.
It’s also worth point out that Lovelock is also a Hockey Stick promoter, as I referenced on Climate Audit: Lovelock and the Revenge of Gaia
This was published in 2006 and so Lovelock has no excuses for ignorance.
Stephen Wilde (13:24:07) :
This seems almost impossible. Let me try one last time [for now]:
There could be lots of subtle, interacting, obscuring, buffered, and variable causes and delays and so forth. This will obscure correlations without denying them, because you cannot deny what you cannot untangle. But, my simple point is that the enthusiasts all claims that the correlations are obvious, strong, robust, ‘drastic’, etc, and THAT is what I challenge. They are NOT obvious, strong, etc. Sigh, this last try will probably be in vain as well, as all the objections just looked like knee-jerk reactions.
Ventana,
I’m guessing that TCN stands for Totally Clueless Newbies.
It would apply to me, anyway.
Sorry to frustrate you, Lief.
I think it has to be a judgement call in the absence of better evidence and my judgement differs from yours.
I wouldn’t claim certainty but there is enough of a correlation to merit proper consideration rather than dismissal of the possibility.
David A (14:21:51) :
Leif; did the temperature 100 years ago in SC 13 start from the same base? If the starting point was different there would be no reason to expect the end point ot be the same. Just asking.
Yes, -273 degrees Centigrade.
Stephen Wilde (14:22:52) :
when the lag is highly variable as in my oceanic scenario ?
In other words a correlation can be noticeable and true but extremely difficult to verify statistically but relatively easy to verify on a simple graph plotted over enough time.
No, there are statistical tools for this, e.g. wavelet power spectra. And I failed again. The correlations people claim as strong evidence do not show any variable lags. They don’t say: “here the temp max lines up with solar min 27 years ago, but over here the temp min lines up with solar max 8 years ago…” etc. well, perhaps some do, but such wiggle matching is usually not taken seriously.
Stephen Wilde (15:04:12) :
Sorry to frustrate you, Leif.
I’m not really frustrated, just a bit puzzled over how hard this is, but it does teach something about human nature.
I wouldn’t claim certainty but there is enough of a correlation to merit proper consideration rather than dismissal of the possibility.
Nobody is dismissing the possibility, just the correlations, after giving them proper consideration, but finding them wanting. But, as you said, your bar is much lower than mine.
Neil Crafter (12:41:12) : DAV, of course that wouldn’t disprove it! I don’t think it can be disproved in their minds
I’m afraid that’s where this is headed. I’m getting tired of the it’s obvious, everybody says so and other specious claims. It’s time we started pinning them down to falsifiable specifics and stop letting them move the goal posts or give orthogonal answers to direct questions.
Our claim is that the climate to date is natural. It’s the default position by definition. It’s not our job to supply theories for natural climate. Asking otherwise is plain misdirection. It should be remembered the AGW proponents need to supply proof of any non-natural claim, including the means of its disproof.
Lets stop letting them wriggle out of this.
I sometimes wonder whether “sceptics” read science papers. This paper provides zero, none, zilch information on temperature trends and the role of solar activity in their variation.
This is the very reason why I state there is no science debate.