Nicola Scaffetta sent several people a copy of his latest paper today, which address the various solar TSI reconstructions such as from Lean and Rind 2008 and shows contrasts from that paper. While he suggests that TSI has a role in the temperature record, he also alludes to significant uncertainty in the TSI record since 1980. He writes in email:
…note the last paragraph of the paper. There is a significant difference between this new model and my previous one in Scafetta and West [2007]. In 2007 I was calibrating the model on the paleoclimate temperature records. In this new study I “predict” the paleoclimate records by using the solar records. So, I predict centuries of temperature data, while modern GCMs do not predicts even a few years of data!
Empirical analysis of the solar contribution to global mean air surface temperature change. Journal of Atmospheric and Solar-Terrestrial Physics (2009),
doi:10.1016/j.jastp.2009.07.007 By Nicola Scafetta
Abstract
The solar contribution to global mean air surface temperature change is analyzed by using an empirical bi-scale climate model characterized by both fast and slow characteristic time responses to solar forcing: and
or
. Since 1980 the solar contribution to climate change is uncertain because of the severe uncertainty of the total solar irradiance satellite composites. The sun may have caused from a slight cooling, if PMOD TSI composite is used, to a significant warming (up to 65% of the total observed warming) if ACRIM, or other TSI composites are used. The model is calibrated only on the empirical 11-year solar cycle signature on the instrumental global surface temperature since 1980. The model reconstructs the major temperature patterns covering 400 years of solar induced temperature changes, as shown in recent paleoclimate global temperature records.
Excerpts from the Conclusion (from a pre-print provided by the author)
Herein I have analyzed the solar contribution to global mean air surface temperature change. A comprehensive interpretation of multiple scientific findings indicates that the contribution of solar variability to climate change is significant and that the temperature trend since 1980 can be large and upward. However, to correctly quantify the solar contribution to the recent global warming it is necessary to determine the correct TSI behavior since 1980. Unfortunately, this cannot be done with certainty yet. The PMOD TSI composite, which has been used by the IPCC and most climate modelers, has been found to be based on arbitrary and questionable assumptions [Scafetta and Willson, 2009]. Thus, it cannot be excluded that TSI increased from 1980 to 2000 as claimed by the ACRIM scientific team. The IPCC [2007] claim that the solar contribution to climate change since 1950 is negligible may be based on wrong solar data in addition to the fact that the EBMs and GCMs there used are missing or poorly modeling several climate mechanisms that would significantly amplify the solar effect on climate. When taken into account the entire range of possible TSI satellite composite since 1980, the solar contribution to climate change ranges from a slight cooling to a significant warming, which can be as large as 65% of the total observed global warming.
…
This finding suggests that the climate system is hypersensitive to the climate function h(T) and even small errors in modeling h(T) (for example, in modeling how the albedo, the cloud cover, water vapor feedback, the emissivity, etc. respond to changes of the temperature on a decadal scale) would yield the climate models to fail, even by a large factor, to appropriately determine the solar effect on climate on decadal and secular scale. For similar reasons, the models also present a very large uncertainty in evaluating the climate sensitivity to changes in CO2 atmospheric concentration [Knutti and Hegerl, 2008]. This large sensitivity of the climate equations to physical uncertainty makes the adoption of traditional EBMs and GCMs quite problematic.
About the result depicted in Figure 6, the ESS curve has been evaluated by calibrating the proposed empirical bi-scale model only by using the information deduced: 1) by the instrumental temperature and the solar records since 1980 about the 11-year solar signature on climate; 2) by the findings by Scafetta [2008a] and Schwartz [2008] about the long and short characteristic time responses of the climate as deduced with autoregressive models. The paleoclimate temperature reconstructions were not used to calibrate the model, as done in Scafetta and West [2007]. Thus, the finding shown in Figure 6 referring to the preindustrial era has also a predictive meaning, and implies that climate had a significant preindustrial variability which is incompatible
with a hockey stick temperature graph.
The complete paper is available here:
Empirical analysis of the solar contribution to global mean air surface temperature change.
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The peer-reviewed work that effectively roasts the AGW alarmists is mounting steadily. Will President Obama follow through on this promise to return scientific integrity to the governing processes?
Perhaps John Holdren, Jane Lubchenco, Steven Chu, and Carol Browner need to pay close attention to Scafetta’s conclusion: “The PMOD TSI composite, which has been used by the IPCC and most climate modelers, has been found to be based on arbitrary and questionable assumptions. . . . climate had a significant preindustrial variability which is incompatible
with a hockey stick temperature graph.”
Taking into account the warm bias in the surface temperature record, this wouldn’t leave much for CO2….
What he does [his Figure 5] is trying to show that the rise in Temps since 1980 is much larger than can be accounted for by any of the assumed TSI-reconstructions. One could argue that this could be due to three things
1) his model is wrong
2) TSI is wrong
3) Temp increase is due to CO2 and not solar activity.
Clearly he excludes (1). And since he believes that the climate is hyper-sensitive to solar changes, he concludes (2).
He is partly correct. All of his choices of TSI [A, B, or C] have two problems:
a) they are based on the Group Sunspot Number which is indeed wrong
b) they show a secular increase in the first half of the 20th century that didn’t happen
Unfortunately, those errors also invalidates his calibration.
OT. More doom and gloom courtesy of the BBC http://news.bbc.co.uk/1/hi/sci/tech/8205864.stm
I haven’t read the paper. Why does he say the TSI is uncertain since 1980?
There are some irritating typos in the captions to the Figures: where he says: “The model is forces with the TSI” he probably means “The model is forced with the TSI”, condisering that s and d are adjacent keys.
Really interesting but Figure 6 is not showing here or at the link.
Hm, Well, here you go everybody:
http://www.fel.duke.edu/~scafetta/pdf/Scafetta-JASP_1_2009.pdf
I love this! The past four weeks have delivered one trip hammer blow after another to the AGW frauds. Real science will eventually trump all fictions. A few of us may be burned at the stake, drawn, quartered, dissed, or otherwise abused by the “faithful,” but Science and Facts will win in the end.
Color me, another delighted physicist.
Leif Svalgaard (09:41:48) : 1. There is a fourth possibility, namely that the rise is not real but an artifact of the warm bias in the data (I personally believe that that is part of it, but some is probably due to CO2 also.
2. “Unfortunately, those errors also invalidates his calibration.” No. It may invalidate the “reconstruction” part of the “solar signature”, but the calibration has nothing to do with any of those things you mentioned and is made solely on the basis of the TSI composite records (PMOD and ACRIM).
But here’s an idea, why doesn’t somebody try redoing all the calculations and see if the tiny difference between your reconstruction (Leif) and Solanki’s group (Krivova) actually effects the pre-satellite results. I think it probably doesn’t matter as much as you suppose.
Scafetta provides a predictive empirical model incorporating dynamic parameters driven by TSI. Svensmark’s climatology theory of solar parameters modulating cosmic rays which modulate clouds and albedo may provide the major link between TSI and climate.
Their predictions can be tested against those of CO2 driven global climate models. May the best model(s) win.
Leif Svalgaard (09:41:48) :
What he does [his Figure 5] is trying to show that the rise in Temps since 1980 is much larger than can be accounted for by any of the assumed TSI-reconstructions. One could argue that this could be due to three things
1) his model is wrong
2) TSI is wrong
3) Temp increase is due to CO2 and not solar activity.
Or:
4. Recent increase in speed of magnetic poles drift, affecting oceans’ conveyor belt circulation.
http://hal.archives-ouvertes.fr/docs/00/40/88/86/PDF/NATA.pdf
Leif Svalgaard
“condisering”
Leave the jokes to the professionals! 🙂
In the first image, the correlation between solar activity and ENSO & volcano adjusted temperature may be deceiving. Note that the rises in temperature occured on three occasions: 1976-8, 1986/7, and 1997/8 – three major El Nino events. These El Ninos released the heat building up in the tropics from El Nino dominant conditions poleward during the period 1976-1998.
I have a new post up using sea level data to show beyond a doubt that this is how the system works.
http://climatechange1.wordpress.com/2009/08/18/sea-level-data-exposes-el-ninos-secret/
As he says: “The ACRIM-PMOD controversy is quite complex”
But there is too much “pathos” (passion) around this. pointing perhaps to something that really happened back then in the 80’s and which irritates those who want temperatures only related to CO2 instead of what common sense indicates: the Sun (that round and brilliant thing up there which warm us all).
As the proverb says: “when the river sounds it’s because it’s carrying pebbles down”
If Scaffetta’s model were correct (and I have no idea whether it is, or whether the problems that Leif brings up are dealbreakers), then shouldn’t the conclusion from this paper be that we really don’t know what caused the temperature rise since 1980? It could be CO2, it could be the sun, it could be a combination of the two, or it could be some other player that as (up to now) been assumed moot.
The sooner the better: timetochooseagain (10:08:52) : Thanks for your fast link to the paper:
http://www.fel.duke.edu/~scafetta/pdf/Scafetta-JASP_1_2009.pdf
timetochooseagain (10:17:21) :
2. “Unfortunately, those errors also invalidates his calibration.” No. It may invalidate the “reconstruction” part of the “solar signature”, but the calibration has nothing to do with any of those things you mentioned and is made solely on the basis of the TSI composite records (PMOD and ACRIM).
“ESS curve has been evaluated by calibrating […] (2) by the findings by Scafetta (2008) and Schwartz (2008) about the long and short characteristic time responses of the climate as deduced with autoregressive models.”
There is little doubt that the solar cycle signal is of the order of 0.1K. The response times, however, cannot be determined from just the last few decades and here the long-term behavior sneaks in through the backdoor.
BTW, I’m puzzled by people saying that this kill’s AGW dead. Rather Scafetta shows clearly [if he is correct] that by far the greatest contribution since 1980 is not solar [his figures 5 and 6]. Al Gore could use Scafetta’s Figures as great support for AGW.
Correlation is not causation, but… Could it be another no solar causation?:
http://www.biocab.org/Correlation_Coefficient_TSI.jpg
Notice the correlation between asymmetries of ΔT and TSI in the last 50 years (approximately since the operation of satellites) are almost all positive.
An asymmetry is described as the deviation of an obtained magnitude from an accepted standard magnitude, 1364.5 W/m^2 for TSI and 0 K for ΔT. I took 0 K for ΔT because it would be a deviation as from the baseline, and the baseline for change of temperature is 0.0 K.
timetochooseagain (10:17:21) :
<iThere is a fourth possibility, namely that the rise is not real but an artifact of the warm bias in the data (I personally believe that that is part of it, but some is probably due to CO2 also.
“the ESS curve has been evaluated by calibrating the proposed empirical bi-scale model only by using the information deduced: (1) by the instrumental temperature and the solar records since 1980 about the 11-year solar signature on climate;”
So, the biased temperature was used in the calibration too. The big problem is the short lever arm. Use 20 years to calibrate and then extrapolate to 400 years, especially when the TSI is uncertain and the temperatures are biased over the calibration period.
BTW, I found the paper almost unreadable, with a clear lack of focus and with the burying of important details in other publications. Had I been a referee, I would have insisted on at least a short statement of summary of where these other statements are based on. [end gripe]
vukcevic (10:33:22) :
4. Recent increase in speed of magnetic poles drift, affecting oceans’ conveyor belt circulation.
At least we can discuss Scafetta’s finding as it is plausible and quantified. Yours is neither.
vukcevic (10:33:22) : What is it the cause of that “Recent increase in speed of magnetic poles drift” ?
Dr. Svalgaard @ur momisugly 11:15:54
I’m glad you said it. I was afraid to…
All of his choices of TSI [A, B, or C] have two problems:
a) they are based on the Group Sunspot Number which is indeed wrong
b) they show a secular increase in the first half of the 20th century that didn’t happen
Are not PMOD and ACRIM direct satellite measurements of TSI (as opposed to to sunspot-based measures)?
Leif Svalgaard (11:15:54) :
“There is little doubt that the solar cycle signal is of the order of 0.1K. ”
I totally agree with you that TSI alone is not sufficient to produce the effects observed, especially with the results of Lindzen, Spencer and others showing negative feedback on radiative perturbations, meaning that TSI variations would be attenuated, not amplified.
Which leaves cosmic rays and clouds. The energy transfer is still small, but the energy entering the camera lens is small too, but you still get the picture. Its what’s inside the camera that counts.