"if the data doesn’t exist, the question can’t be answered"

#4133 Johnathan Overpeck – IPCC review.
   … what Mike Mann continually fails to understand, and no amount of references will solve, is that there is practically no reliable tropical data for most of the time period, and without knowing the tropical sensitivity, we have no way of knowing how cold (or warm)the globe actually got.

… Unsatisfying, perhaps, since people will want to know whether 1200 AD was warmer than today, but if the data doesn’t exist, the question can’t yet be answered.

Tiim Osborne #4007
   Also we have applied a completely artificial adjustment to the data after 1960, so they look closer to observed temperatures than the tree-ring data actually were

Tim Osborne #2347
   Also, we set all post-1960 values to missing in the MXD data set (due to decline), and the method will infill these, estimating them from the real temperatures – another way of “correcting” for the decline, though may be not defensible!