Weather Modification

The term weather modification refers to any deliberate effort on the part of humans to influence weather patterns for some desirable purpose. Probably the most familiar example of weather modification is the seeding of clouds, most often done in order to increase the amount of precipitation during periods of drought.

The earliest scientific programs on weather modification date to the 1940s when Vincent J. Schaefer carried out experiments on cloud seeding. A half century later, the science of weather modification is still in its infancy with many questions surrounding the most effective way of bringing about the changes desired in any particular setting. The major types of weather modification that are currently in use or under study include cloud seeding, frost prevention, fog and cloud dispersal, hurricane modification, hail suppression, and lighting suppression.

Some defense experts have suggested the use of weather modification techniques as a military weapon. The claim has been made, for example, that the United States used cloud seeding during the Vietnam War. The hope was that increased rainfall would make the movement of personnel and material along the Ho Chi Minh trail more difficult.