Clean Air and Geoengineering Prohibition Act.

Wyoming's HB 12, the Clean Air and Geoengineering Prohibition Act, bans releasing substances into the state's airspace for climate, weather, or solar radiation modification (like stratospheric aerosol injection or solar radiation management). It directly affects entities conducting such atmospheric experiments, including research groups, corporations, or government agencies, while exempting commercial aviation, cloud seeding, agricultural operations, and fire suppression. The law requires the Wyoming Department of Environmental Quality to monitor airspace and enforce the ban by issuing cease-and-desist orders for violations. It explicitly permits existing activities like cloud seeding and standard aviation emissions, focusing only on intentional modifications not already authorized by law.