Loehle and Scafetta calculate 0.66°C/century for AGW
Guest post by Craig Loehle and Nicolas Scafetta
Human Effect on Climate Clearly Detected (but is 0.66 deg C/100yr since ~1950!)
Loehle, C. and N. Scafetta. 2011. Climate Change Attribution Using Empirical Decomposition of Historical Time Series. Open Atmospheric Science Journal 5:74-86.
The study is available via free open access at http://benthamscience.com/open/toascj/articles/V005/74TOASCJ.htm (links to full paper and supplemental information, both PDF, follow at the end of this post)
How do we detect the influence of humans on the climate system? Current methods based on climate models are unfortunately circular: their estimate of human effects is only valid if the models are correct, but the models make certain assumptions and also are fitted to the historical temperature record. A model-independent estimate of climate response is needed and is provided by this study. (WUWT)
As far as I can tell from a quick survey of this study and discussion between the authors and properly skeptic scientists, this assumes an anthropogenic component and then attempts to more reasonably analyze the effect of that assumption. It’s substantially less than the dire predictions by IPCC, Gore, et.al., but still uses models and makes assumptiions. It may be useful in differentiating guesswork from exaggeration.