The amount of aerosol you need to I next is enormous, it needs to be sprayed at an altitude higher than realistic means of injection are feasible, and it has to be done in a way that doesn’t produce so much CO2 that it defeats the point.
Can you imagine an extant tech that can come close to doing that at the required scale? I can’t.
High altitude solar drone gliders that collect low level water vapor and spray it to form ice.