>The atmosphere has varied for billions of years between an average temperature of 10C and 25C.

Which we could not care less about. Humanity didn't exist for "billions of years" and for most of the time it did exist it existed in an animal like state and died by the droves with bad weather conditions.

It also didn't have to sustain a fragile modern infrastructure, megacities, argiculture to feed 8 billion, and so on.

So whether 1 billion years ago it was also "50 degrees C" or "5 degrees C" is irrelevant as to our predicament now.

And that's without considering other aspects of environmental issues, like microplastics, overfishing, polluted water systems, and so on, that are 100% man-made.

>Look at history to place current events in proper context.

Your "billions" of years ago, or even 10.000 years ago, is not history, it's pre-history.