I really don't know what to think about this topic. I think for most of us, when we discuss history, we tend to think of history as our own life cycle and what we've experienced. I know the 80's was a great decade for me, as I love snow and colder temps. We have definitely warmed since then. My grandfather was born in 1907, when the early 90's rolled around, temps were warming already (so it seemed). He would tell me his grandfather would talk about the heat he experienced during his childhood. I imagine where we are at with global temps is not uncharted territory.
We can pollute the planet, we can destroy our ecosystems, we can trash it, we can do a lot of things, however, to cause the temperature to rise to the point of making it uninhabitable seems like a very far stretch to me. Hell, we can't even have a climate change summit without it being cancelled due to ice and snow.