By Frank Bosse, via Die kalte Sonne
It’s known that GISS does not process the temperature data as they are determined but rather “corrects” them. Such corrections may make sense, but to what extent they influence warming trends remains an open question. Gavin Schmidt, the director and responsible person for the measurement series, recently tweeted some peculiar things:
Image: Twitter screenshot
He notes that the overall trend decreases with the corrections (green compared to the raw data (black dashed). Now, however, it is the case that the anthropogenic influence on the warming only becomes noticeable after 1950.
If we now digitize this part of the overall series, a completely different picture emerges:
Although the trend decreases from 1880 to 1950, this is relatively insignificant for calculations of climate sensitivity, for example, because very little anthropogenic forcing occurred during this time.
After 1950, however, we see a 13% trend shift due to the “corrections”. This was also quickly communicated on Twitter and one has to wonder why Gavin Schmidt mentioned this irrelevant reduction in early trends so prominently. Smokescreen?