The only method put out there is spraying 'dust' into the atmosphere which is what chem trails are all about. I find this unconvincing simply because incoming radiation is converted sooner or later to infrared radiation in the atmosphere and can differ little from hitting the ground.
It is a terrible idea anyway based on a false analysis pushed by political interests as fact.
The big problem is that our human created deserts do release a lot of infrared energy back into space during the night. This already has caused our global environment to cool by around two degrees since the Bronze Age. We can reverse that and produce a vastly better global energy profile..