I feel really helpless, one person alone is essentially powerless, only governments and corporations are big enough to make a difference but they don't because they don't "believe" it or have no incentives to do anything. (And no, boycotts are pointless). So essentially we are screwed and the people who will come after us will either have to come up with a technology to get CO2 out of the atmosphere back to 290-300 ppm or will have to live with a much more hostile environment than today.
I'm extremely pessimistic right now.