It's like thatABC2019 wrote:I am more interested in knowing with what precision one can measure the average temperature of the earth 100 years ago!
It's an obsession with you
However, there is plenty of literature on this subject.We have known this with a fairly good precision for at least 400000 years thanks to the air bubbles trapped in the ice cores among other things.
Perhaps going back in the history of climatology will help you, well it helped me ...
Everything is not there, but in the archives of the site, you should find ...The little story goes that it was Claude Lorius, a French scientist, who, watching a piece of ice melted in his whiskey, taken from the depths of the Antarctic ice sheet and observing the sparkling of air bubbles tens of thousands of years old. years, had the intuition that analyzing the chemical composition of such an old air could be of scientific interest and perhaps provide information on the climate of the time when these bubbles were trapped.
But before being able to carry out these analyzes, it was necessary to have “old” ice and therefore take it as deeply as possible, down to the bedrock if possible ...
Paleoclimatology validates Milankovitch's astronomical theory:
The most remarkable result, mentioned above, is to be attributed to an American trio, Hay, Imbry and Shackleton who in 1976 presented the analysis of two cores from the Indian Ocean, covering the whole of the last glacial cycle, in which they had measured several different parameters related to climate, including variations in the 18O / 16O ratio in foraminifers, carbonate contents which reflected the abundance of calcareous shell organisms, and variations in foraminifera populations themselves, some having known affinities for precise temperature intervals. The evolution of these parameters was consistent in accordance with the astronomical theory of Milankovitch, unfortunately deceased for twenty years ...
"The model based on astronomical theory predicts that the cooling that began 6 years ago will continue for another 000 years before the climate warms slightly and then plunges into glacial conditions in about 5 years."
This shows the confidence given to this theory which seemed to settle definitively the question of the causes of glacial-interglacial alternations, at least those of the Quaternary.
For example Michel Petit answered your question in 2015 https://argonautes.club/peut-on-parler- ... diale.html
