Current technology is not ready for massive geoengineering actions. Furthermore, there is not enough scientific data to ensure geoengineering is safe and will not create additional climate issues.

So the only thing that can be done for now against global warming is to reduce emissions of CO2 and CH4.

Sun is not the cause of global warming. Since 1970 sun activity is decreasing but Earth keeps warming.

https://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm