«Mike's Nature trick» referred to the technique of plotting recent instrumental temperature data along with historical reconstructed data. (climateaudit.org)
It appears that Ghil, and others specifically warn against the use of MEM and temperature data: «Instrumental temperature data over the last few centuries do not seem, for instance, to determine sufficiently well the behavior of global or local temperatures to permit a reliable climate forecast on the decadal timescale by this SSA - MEM method.» (realclimate.org)
The trick is not merely «plotting recent instrumental temperature data along with historical reconstructed data.» (climateaudit.org)