The field of weather modification requires the use of specialized equipment to carry out operations and research. Cloud seeding materials, primarily silver iodide, have been extensively reviewed with regard to their environmental safety. Examples of some of the commonly used equipment, further explanation of the basic methods and techniques, and more on environmental stewardship can be found here.
Cloud seeding can be applied from the ground or the air. Each is briefly described here.
Winter and summer airborne and ground-based seeding concepts are described here.
Silver iodide is the primary seeding agent used in cloud seeding. Its tremendous efficiency as an ice nucleus allows it to be used in minute quantities. Silver iodide has been extensively reviewed as to its environmental safety during the last half-century. The published findings of this research clearly show no environmentally harmful effects arising from cloud seeding have been observed, or are expected to occur.