/sci/ - Science & Math

>>7480377
>>>7480346 (You)
>>Then why is the distant past cooled so much even thought the Urban Heat Island (UHI) effect is weak back then, but recent temperatures are cooled little, or even warmed, event though the UHI is much stronger.
>Because UHI is not the only source of errors in the temperature record.

You are indeed correct. The GISS "correcting" algorithm is a huge source of error.
Here is Clean Station Data. These data are from NOAA Class 1 temperature stations. Meaning they have no problems with their temperature record, setting, instrumentation etc. They provide pristine data. Yet these data are "corrected."

First pic here, GISS cooled the past for the suburban station near Baker OR and as well as cooling the past for rural Hobart OK. Check the temp scales on each graph carefully, they are not always the same from left to right.