"Atmospheric sulfate aerosols" means spraying sulfuric acid into the air. It's all the joy of this solution with the added bonus of primarily blocking visible light, destroying the ozone layer, and scattering light so that solar panels and plant life don't work as well. Oh yeah, and SPRAYING ACID INTO THE AIR. Intentional acid rain, forever. It's an incredibly foolish, destructive idea that people with zero drive to do basic research support vocally.
The cheapest, easiest and safest way to fight climate change is to stop emitting CO2. It would be so incredibly easy to stop 80% of anthropogenic emissions. These geoengineering plans are worse in every way.
[1]: https://en.wikipedia.org/wiki/Stratospheric_sulfur_aerosols