Question

Why earth has the most identical temperature conditions

Answer 1

first of all the phenomenum we are presently considering is happening on a very short time scale compared to the billions of years our planet has already lived : a century represents only 0,0000025% of earth’s age ! It is of course possible to get some hints on what were the average climatic conditions on earth a very long time ago (say a couple millions years, or a couple of hundred million years), but it will not be possible to know precisely how things evolved over a century then. For example, it is not possible to know how the average climatic conditions evolved between 60.000.000 years before present and 60.000.100 before present (or between 60.000.000 years before present and 59.999.900 years before present).