By Joseph D’Aleo, Icecap

Our national centers regard station data as critical to measure recent climate change. The raw observations are taken from the stations then adjusted to account for local factors like site changes, changes in instrumentation, time of observation and in some cases urbanization (Karl 1988). One would think the differences would be small and that once adjusted, the data would stand the test of time.

We found that to be far from the truth by examining the data sets for our biggest city, New York City and the climate station in Central Park. We have looked at this in two separate blogs. I have combined the two and added to it in this analysis.

Central Park, New York City Observing Site at Belvedere castle

I find the data mind boggling. For our own government to maintain three different versions of historical data for a single site whose average July temperature for much of the record varies by 11F! and where the adjustments to the data decrease in recent years introducing a warming not in the raw data.  These kinds of variances and ‘adjustments” in the “data” have got to have you question whether we can trust any surface station based data set to determine changes the order of a tenth of a degree for climate change assessment.

See the updated analysis here.