We applied the same method used in the observational analysis on general circulation model data to decrease the statistical uncertainty at the expense of an increased systematic uncertainty. (climateprediction.net)
Given that we only have two examples of this metric, the true systematic uncertainty is clearly larger than the simply the difference between them. (realclimate.org)
The new 17 - author paper (accessible pdf)(lead by Ben Santer), does a much better job of comparing the various trends in atmospheric datasets with the models and is very careful to take account of systematic uncertainties in all aspects of that comparison (unlike Douglass et al). (realclimate.org)