Prohibit weather modification.

SB 473 prohibits most weather modification activities in Montana, specifically banning large-scale "geoengineering" projects like spraying particles into the atmosphere to alter climate (e.g., stratospheric aerosol injection or marine cloud brightening). It exempts established cloud seeding practices used for agriculture and snowmaking under existing law (85-3-101 through 85-3-424). The bill directly affects researchers, companies, or entities conducting weather-altering experiments within Montana’s borders. Key provisions ban intentionally releasing chemicals or devices for weather control, temperature modification, or sunlight intensity changes, except for permitted cloud seeding. The law takes immediate effect upon enactment.