Montana : 2025 Regular Session : BILL SB473
Prohibit weather modification.
Sponsor: Sen Bob Phalen
Bill Details
Prohibit weather modification.
GeoLawWatch Bill Summary
The bill prohibits geoengineering activities within Montana but makes an explicit exception for traditional cloud seeding practices used for water resource management, which remain permitted.
To clarify the scope of these restrictions, the legislation sets forth the following provisions: Specifically banned practices include stratospheric aerosol injection. Also forbidden are solar radiation management techniques like space-based reflectors and cloud albedo enhancement. Marine cloud brightening, which involves spraying sea-salt particles into marine clouds to increase reflectivity and reduce the amount of solar radiation absorbed by Earth, is also prohibited.
In addition, solar radiation management is likewise prohibited.
Marine cloud brightening is explicitly banned.
The Legislature states its rationale for these prohibitions. It justifies these actions by determining that geoengineering poses risks to the environment and public health. The risks stem from its experimental nature and potential for unintended consequences.
Explicit exception: Cloud seeding is not prohibited by the bill. Specifically, cloud seeding—defined as increasing precipitation within existing cloud systems to support water resource management, such as for agriculture and snowmaking—remains legal and continues to be regulated under Title 85, Chapter 3, of the Montana Code Annotated.
The prohibition is incorporated in Title 75, Chapter 2, of Montana's environmental laws and is subject to its enforcement provisions.
Although the bill does not specify penalties or enforcement mechanisms, it incorporates the provisions of Title 75, Chapter 2. These provisions govern environmental quality and provide a framework for enforcement. By referencing existing legal structures, the bill indirectly addresses enforcement.
Effective date: The act becomes effective immediately upon passage and approval.
History
This bill had a dramatic and turbulent path through the legislature, surviving a near-death experience on the Senate floor before ultimately failing in the House. The bill was assigned to a drafter in November 2024 but did not enter active drafting until mid-February 2025, with introduction occurring on February 25. Senate Natural Resources held a hearing just three days later and passed the bill on March 3. However, the Senate floor proved contentious: on March 5, after an amendment was adopted, the bill was indefinitely postponed and a motion to pass failed. In an unusual procedural reversal, the Senate reconsidered its action and returned the bill to second reading. The following day, March 6, the bill passed both second and third readings and was transmitted to the House.
House consideration moved more slowly, with the bill waiting ten days before referral to the House Natural Resources Committee. After a hearing on March 24, the committee took two weeks before voting to concur with amendments on April 7. When the bill reached the House floor for second reading on April 10, members voted "Not Concurred," rejecting the measure just as the House had done with the 2021 bill. The bill formally died in process on May 23, 2025, following what appears to be a session adjournment, marking another instance of a geoengineering-related measure clearing the Senate only to fail on the House floor.
- Sun 17 Nov 2024 (LC) Drafter Assigned
- Wed 19 Feb 2025 (LC) Draft in Legal Review
- Thu 20 Feb 2025 (LC) Draft in Edit
- Sun 23 Feb 2025 (LC) Draft in Input/Proofing
- Sun 23 Feb 2025 (LC) Draft in Final Drafter Review
- Mon 24 Feb 2025 (LC) Draft in Assembly
- Mon 24 Feb 2025 (LC) Draft Ready for Delivery
- Mon 24 Feb 2025 (LC) Draft Delivered to Requester
- Tue 25 Feb 2025 (S) Introduced
- Tue 25 Feb 2025 (S) First Reading
- Tue 25 Feb 2025 (S) Referred to Committee (S) Natural Resources
- Fri 28 Feb 2025 (S) Hearing (S) Natural Resources
- Mon 03 Mar 2025 (S) Committee Executive Action--Bill Passed (S) Natural Resources
- Tue 04 Mar 2025 (S) Committee Report--Bill Passed (S) Natural Resources
- Wed 05 Mar 2025 (S) 2nd Reading Motion to Amend Carried
- Wed 05 Mar 2025 (S) 2nd Reading Indefinitely Postponed
- Wed 05 Mar 2025 (S) 2nd Reading Pass Motion Failed
- Wed 05 Mar 2025 (S) Reconsidered Previous Action; Placed on 2nd Reading
- Thu 06 Mar 2025 (S) Scheduled for 2nd Reading
- Thu 06 Mar 2025 (S) 2nd Reading Passed
- Thu 06 Mar 2025 (S) Scheduled for 3rd Reading
- Thu 06 Mar 2025 (S) 3rd Reading Passed
- Fri 07 Mar 2025 (S) Transmitted to House
- Mon 17 Mar 2025 (H) Referred to Committee (H) Natural Resources
- Mon 17 Mar 2025 (H) First Reading
- Mon 24 Mar 2025 (H) Hearing (H) Natural Resources
- Mon 07 Apr 2025 (H) Committee Executive Action--Bill Concurred as Amended (H) Natural Resources
- Tue 08 Apr 2025 (H) Committee Report--Bill Concurred as Amended (H) Natural Resources
- Thu 10 Apr 2025 (H) Scheduled for 2nd Reading
- Thu 10 Apr 2025 (H) 2nd Reading Not Concurred
- Fri 23 May 2025 (S) Died in Process
Consolidated Bill Text
BE IT ENACTED BY THE LEGISLATURE OF THE STATE OF MONTANA
NEW SECTION Section 1 Prohibiting weather modification BY GEOENGINEERING 1 THE LEGISLATURE FINDS THAT GEOENGINEERING POSES RISKS TO THE ENVIRONMENT AND PUBLIC HEALTH DUE TO ITS EXPERIMENTAL NATURE AND POTENTIAL FOR UNINTENDED CONSEQUENCES
2 Except as FOR WEATHER MODIFICATION BY CLOUD SEEDING AS prescribed in TITLE 85 CHAPTER 3 a person may not intentionally inject release or disperse chemicals chemical compounds substances or apparatuses within the borders of Montana expressly for GEOENGINEERING
3 As used in this section
A CLOUD SEEDING MEANS A PROVEN METHOD OF INCREASING PRECIPITATION WITHIN EXISTING CLOUD SYSTEMS TO SUPPORT WATER RESOURCE MANAGEMENT EFFORTS INCLUDING FOR AGRICULTURE AND SNOW MAKING
B GEOENGINEERING MEANS LARGE-SCALE INTENTIONAL INTERVENTIONS IN THE EARTHS CLIMATE SYSTEM DESIGNED TO COUNTERACT OR MITIGATE GLOBAL CLIMATE CHANGE INCLUDING STRATOSPHERIC AEROSOL INJECTION SOLAR RADIATION MANAGEMENT AND MARINE CLOUD BRIGHTENING THAT INVOLVE ALTERING ATMOSPHERIC OCEANIC OR TERRESTRIAL SYSTEMS ON A PLANETARY SCALE WITH POTENTIALLY UNPREDICTABLE AND WIDESPREAD ENVIRONMENTAL CONSEQUENCES
C MARINE CLOUD BRIGHTENING MEANS SPRAYING SEA SALT PARTICLES INTO MARINE CLOUDS TO INCREASE REFLECTIVITY AND REDUCE THE SOLAR RADIATION ABSORBED BY THE EARTH
D SOLAR RADIATION MANAGEMENT MEANS MANAGING SOLAR RADIATION REACHING THE EARTHS SURFACE THROUGH STRATOSPHERIC AEROSOL INJECTION SPACE-BASED REFLECTORS OR CLOUD ALBEDO ENHANCEMENT
E STRATOSPHERIC AEROSOL INJECTION MEANS INJECTING REFLECTIVE PARTICLES INTO THE STRATOSPHERE TO REFLECT SUNLIGHT AND REDUCE GLOBAL TEMPERATURES
NEW SECTION Section 2 Codification instruction Section 1 is intended to be codified as an integral part of Title 75 chapter 2 and the provisions of Title 75 chapter 2 apply to section 1
NEW SECTION SECTION 3 EFFECTIVE DATE THIS ACT IS EFFECTIVE ON PASSAGE AND APPROVAL