This is pretty straight forward–carbon dioxide is plant fuel, plants make the earth livable by making oxygen.
Simple stuff. Ideal plant environment is 1000 to 1500 PPM CO2 and we are at 400–more Barbecue and SUVs please.
And recall if you will the big CO2 and heat sink is the oceans, and the oceans are effected by circulatory effects that have nothing to do with the piddling human presence on the earth. We are not so important as we think.
I would also recommend that you consider humans and the biosphere would benefit from some warming, in addition to more CO2.