Yeah, I'm not against it!
I had a figure of 40 million tons/year, but I must have lost an 0 somewhere. Still a neat hope, overall. Some super greenhouse gas is needed. I think I remember reading that CO2 was 1000 times more effective than methane, or maybe I got that backwards. SPF 50 is sure a great sun blocker! Somehow I think Venus is a better bet. Easier to subtract gas than add it.
