Cloud seeding - Wikipedia
https://en.wikipedia.org/wiki/Cloud_seedingIn 1891 Louis Gathmann suggested shooting liquid carbon dioxide into rain clouds to cause them to rain. During the 1930s, the Bergeron–Findeisen process theorized that supercooled water droplets present while ice crystals are released into rain clouds would cause rain. While researching aircraft icing, General Electric (GE)'s Vincent Schaefer and Irving Langmuirconfirmed the theor…