MT SB473

Prohibits geoengineering within Montana's borders, defined as large-scale intentional interventions in Earth's climate system designed to counteract global climate change

Specifically bans stratospheric aerosol injection, solar radiation management, marine cloud brightening, and space-based reflectors

Exempts cloud seeding operations for increasing precipitation to support agriculture, snow making, and water resource management under existing Title 85, Chapter 3 regulations

Legislature finds geoengineering poses risks to environment and public health due to its experimental nature and potential for unintended consequences

Effective immediately upon passage and approval; codified under Title 75, Chapter 2 (environmental protection)