Adjustments to climate data always add warming

Strangely, they never add cooling:

Note well that all corrections used by USHCN boil down to (apparently biased) thermometric errors, errors that can be compared to the recently discovered failure to correctly correct for thermal coupling between the actual measuring apparatus in intake valves in ocean vessels and the incoming seawater that just happened to raise global temperatures enough to eliminate the unsightly and embarrassing global anomaly “Pause” in the latest round of corrections to the major global anomalies; they are errors introduced by changing the kind of thermometric sensors used, errors introduced by moving observation sites around, errors introduced by changes in the time of day observations are made, and so on. In general one would expect measurement errors in any given thermometric time series, especially when they are from highly diverse causes, to be as likely to cool the past relative to the present as warm it, but somehow, that never happens.  Indeed, one would usually expect them to be random, unbiased over all causes, and hence best ignored in statistical analysis of the time series.

Note well that the total correction is huge. The range is almost the entire warming reported in the form of an anomaly from 1850 to the present.

Emphasis in the original.  This is a very interesting analysis of the adjustments made to the temperature data sets.