by Courtney Meyerhofer
Did you know Idaho has a cloud seeding program?
Idaho’s Department of Water Resources (IDWR) has a cloud seeding program that is operational November 1st to April 30th annually.
What is it?
Cloud seeding is a weather modification protocol that changes how a cloud forms and precipitates. The goal of cloud seeding is to increase annual rain and snowfall.
What does cloud seeding do?
The IDWR’s monitoring show that the cloud seeding program has on average increased rain and snowfall by 10%.
image by Idaho Power Company
The IDWR’s cloud seeding program involves spraying an “inert” silver iodide (AgI) into the atmosphere. Silver iodide is chosen because it has a hexagonal shape similar to ice and it serves as a surface where snowflakes form inside the cloud.
In this way, cloud seeding mimicks a naturally occuring process — that is, water freezing and growing into a snowflake on a dust particle. Only, instead of naturally occurring atmospheric dust, cloud seeding augments nature by providing silver iodide.
What are the risks to cloud seeding?
From the Wikipedia page on cloud seeding:
“With an NFPA 704 health hazard rating of 2, silver iodide can cause temporary incapacitation or possible residual injury to humans and other mammals with intense or chronic exposure. But several detailed ecological studies have shown negligible environmental and health impacts.[19][20][21].
The toxicity of silver and silver compounds (from silver iodide) was shown to be of low order in some studies.
These findings likely result from the minute amounts of silver generated by cloud seeding, which are about one percent of industry emissions into the atmosphere in many parts of the world, or individual exposure from tooth fillings.”
This excerpt from Wikipedia highlights how the use of silver iodide, while generally recognized as safe, is mostly unknown.
This is one of the many unknowns in the cloud seeding program:
how much silver iodide is released each year?
how effective is it and how do we know it’s effective?
how might silver iodide affect wildlife habitats and soil quality?
how is this program being monitored for human health effects?
Cloud Seeding Program Administration
Idaho’s cloud seeding program is funded by participating counties and was authorized by Idaho House Bill 266 in 2021.
Closing thoughts
For the potential benefits of additional precipitation, spraying a substance (AgI) that may cause health issues or environmental degrade without the public’s informed consent is at best risky.
There is also difficulty admitted among climate scientists in assessing how well cloud seeding works. It’s not straightforward to see if a cloud that’s seeded will actually produce more than expected. This means it’s challenging to meaningfully measure how well a cloud seeding program is performing aside from comparing annual precipitation in treated zones from year to year.
The issue of cloud seeding shows how our local state representatives, legislators, and decision-makers have an undeniable impact on our health and environment. Yet the modern media would lead you to believe that the Presidential election is the most important event of every 4 year cycle.
If you’d like to get in contact with your legislator, you can find who applies to y our zip code at the Idaho Govt website here.
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