The climate on this planet was not mean't to be artificially engineered by man and I believe that any attempt to do so will have disasterous consequences.
Climate is modulated mostly by clouds, the most common aerosol. Man engineers dams, lakes, rivers to control the second half of the rain cycle. Very little fresh water makes it to the sea anymore without a small group of mostly conservative male engineers deciding when and where. Influencing the first half of the rain cycle is not that much different. While playing with the global climate is foolish, creating man-made clouds for water and weather control is a local issue. Most clouds exist lower than where airplanes fly and rain out within 20 miles, so each state can decide their own climate without UN control.
Just like kudzu controlled erosion in the South.