The Earth is close to its hottest temperature, whilst supporting life.
But it's not really the temperature, it's the fantastically rapid way it has been rising from around 1850.
As others have said, the temperature has swayed one way and another for 1000,000 years or more.
It's the massively accelerated way we have got here, and it shows no sign of slowing.
It might be American oil, Russian gas or Chinese coal, but none of those are going to give up their wealth.
Maybe nature will sort it. But it's not looking good at the moment