There is absolutely no evidence that any human -
engineered GE
scheme that has been
proposed or considered can duplicate «volcanos» effect on global temperature» in any sort of remotely controlled way, let alone «set global temperature like a thermostat».
Those few that have been
proposed (carbon capture and sequestration for all new coal - fired power plants, geo -
engineering schemes, switch to renewables such as wind and solar, etc.) would be extremely costly, could result in unknown and unintended negative consequences and would not bring any significant reduction of theoretical greenhouse warming by 2100.