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 . 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
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  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  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 . 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: