I don't care about cause, you are the one who does. We can mitigate the consequences of sea level rise but poorer countries don't have that option. I'm 100% sure we can fine tune the global climate, I'm just not sure the best way to do it. I know you don't think CO2 is the cause but enough scientists do that they shouldn't be ignored.
I think mandating the raising of the average MGP of cars will, at best, lessen the CO2 going into the air. At worst, it will lessen local air pollution, allow US cars to compete overseas, and cut overall transportation costs. Win-win-win.