So.
173 years of data.
Let’s presume that the 1850, 1875, 1900, 1925, 1950, 1975, 2000, and 2023 data were ALL collected the same way, in the same places, and the “Earth’s temperature” was calculated the same way. That’s false, of course, but just follow along.
Now compare the 173 years that data exists with the 173 years before 1850. What was 1677 like? 1477? 1066?
What was 5000 BC like? 15000 BC? Ten million years ago?
What a load of nonsense.
I wonder if those thermometers were all regularly calibrated for accuracy, too. LOL.