[fallingfrog]

Sorry, I should clarify: Hansen's paper indicated that burning all fossil fuels would create a 16 degree C warming, which would definitely be the end of the line for us, for reasons of heatstroke if nothing else, but in the same paper he does say that the temperature can't go up to Venus levels. So nature would eventually recover.

[m_mueller]

Yes Venus isn‘t possible afaik, but I think around 125C is an equilibrium.