Senate Bill No. introduced by B. Phalen and D. Loge aims to revise laws related to weather modification by prohibiting geoengineering practices in Montana. The bill defines geoengineering as large-scale interventions in the Earth's climate system intended to counteract or mitigate global climate change, which includes methods such as stratospheric aerosol injection and solar radiation management. The legislation allows for an exception for weather modification through cloud seeding, which is recognized as a proven method for increasing precipitation to support water resource management efforts.

The bill emphasizes the potential risks associated with geoengineering, citing concerns over its experimental nature and the possibility of unintended environmental and public health consequences. It establishes new definitions for terms related to weather modification and geoengineering, while also providing an immediate effective date upon passage and approval. The proposed changes will be codified as part of Title 75, chapter 2 of Montana law.