text: The maximum likelihood (minimum log likelihood) is similar for each of the 4 autocorrelation models (though OLS is slightly higher than the others), but the confidence intervals are much wider for AR1 and other schemes. In this example, there isnt much difference between AR1 and more complicated autocorrelation structures (but there are other cases in which the differences are very noticeable.) Ive also plotted the Santer T2LT ensemble mean trend, which is well outside the 95% confidence interval (using maximum likelihood) something that we had previously reported applying the (1-r)/(1+r) degrees of freedom adjustment used in Santer et al. (but they only reported results for obsolete data ending in 1999).