So many thoughts and so little time . . .
First, since the planet has actually been cooling off over the past several years, it might make sense to wait until we actually experience "global warming" again before attempting any artificial cooling.
Second, it would pay to remember the law of unintended consequences before attempting any artificial cooling of the planet. We've got a pretty complex ecosystem here on Earth - intentionally dickering with it might actually get us in more trouble than we have right now.
And third, if (and it is a massive IF) global warming was actually a threat to the planet, Myhrvold's "fix" or something like it would make a heck of a lot more sense and have a heck of a lot more of an effect than reducing CO2 emissions.