I largely agree with what you said but: >As the reasonable costs of climate change (according to the latest IPCC report) have been estimated from 0.2% to 2% of

I largely agree with what you said but: >As the reasonable costs of climate change (according to the latest IPCC report) have been estimated from 0.2% to 2% of global income That assumes we keep carbon below 450ppm and is only up to 2030. Also it only gets down to the bottom end of that range if you pick the most optimistic models.