I think the key difference with us humans is that we have changed the earth far faster than other species did before us, and evolution cannot keep pace.

And, to be honest, if you want to talk about positive evolution from our CO2 production, then I think you should first consider the possible "negative evolution" from medicine. It's not even so much the "negative" evolution from medicine as the massive populations medicine has allowed. Not even our intellect can keep up... If it could, then maybe we'd be ok.

The "craziness" that I think about is that the world would be much better off without modern medicine, even though I would not be here to enjoy it.