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)
4) Warming due to anthropogenic GHG+Aerosol of 0.66 oC/Century is not alarming, in comparison to the IPCC protected 2.3 oC/Century This 0.66 value is an upper bound in our estimation (due to possible poorly corrected UHI and LULC effects that may explain part of the observed warming trend since 1950).
5) Cooling/flat temperatures till 2030 are likely (as also predicted by others).
6) Our result matches the historical record better than any other attribution study and better than GCM outputs.
Loehle & Scafetta 2011 (full paper PDF)
Loehle & Scafetta Supplemental Info (PDF)