I thank you
though I now see that what I had (somewhere !) in mind was the biasing of the 'HI compensation'.....
by extensive and relentless shuffling of the temperature measurement sites ie 'polluting the data set'
this apparently shown by (some) apparently genuine actual meteorologists (not economists or environmentalists)
someone selling 500gm of sugar must prove the traceability of his claim (of 500gm)
but those selling global warming can do so without traceability
and eg .... re 'sea level rise'
the NOAS set aside 150 years of tide gauge measurement continuity (since 1979 using satellite measurements only)
but can't find anyone on the coast whose sea level has risen