"Weird attitudes"? "Vague fears"?
Spraying chemicals in the air does nothing to fix ocean acidification, which will collapse marine life, which will make life hell on shore as well.
And will indirectly make the ocean acidifcation problem worse, since people will continue using fossil fuels.
If it even works at all, which is far from certain.
And blocking the sun won't have any adverse affects on plant life? You know, the primary carbon sink?