Since the creation of the Atmospheric Resource Board (originally the Weather Modification Board) in 1975, a number of evaluations have been made of the effects of the program. These evaluations have been based on a variety of differing data bases. Among them are: ARB Cooperative Observer Network rainfall data, National Weather Service (NWS) rainfall data, crop hail insurance data compiled by the National Crop Insurance Service (NCIS), and wheat yield data compiled by North Dakota State University.
Computer-based numerical models have also played an important role. Economic models have provided estimates of the economic benefits of the program, while cloud models have produced increased insights into the complex processes within the clouds that ultimately govern hail and rain production. All of these evaluations have been independent, that is to say, they've been done by agencies and universities unaffiliated with the ARB, allowing the best qualified persons to do the evaluations, improving the chances for an unbiased, solid, scientific approach.
As of this date, all evaluations of the program have shown either positive or neutral results. No suggestions have been found of negative impacts, either within or outside target areas.
Crop Hail Evaluation
Several evaluations have helped show the effects of cloud seeding for hail suppression in North Dakota. Primarily through the analysis of crop insurance data, studies have found a reduction of crop-hail losses up to 45 percent in the seeded areas versus unseeded upwind control areas. (Read Full Article)
Economic Impact of Reducing Hail and Enhancing Rainfall in North Dakota
A recent study from the NDSU Department of Agribusiness and Applied Economics (Bangsund and Hodur, 2019) describes the significant economic benefits cloud seeding provides to agricultural production in the western North Dakota counties of Bowman, McKenzie, Mountrail, part of Slope, Ward and Williams. (Read Full Article)
Cloud seeding effects on rainfall have been evaluated by several independent scientists using numerous datasets. Results of the studies indicate precipitation increases in and downwind of the seeded areas in percentage amounts ranging from the low single digits to the low teens, with typical results falling in the 5-10 percent range. (Read Full Article)
The effects of cloud seeding on urban areas in North Dakota have not been quantified. (Read Full Article)
Wheat Yield Study
While evaluations that quantify precipitation or hailfall are certainly useful, the “bottom line” for the county-sponsored NDCMP is what effects are found in crop yields. (Read Full Article)
View all of the references used in the above articles along with links to the publications. (View Full List Of References)