The info on this site is quite enlightening. Whoa!
http://www.haarp.net/
The military has had about twenty years to work on weather warfare methods, which it euphemistically calls weather modification. For example, rainmaking technology was taken for a few test rides in Vietnam. The U.S. Department of Defense sampled lightning and hurricane manipulation studies in Project Skyfire and Project Stormfury. And they looked at some complicated technologies that would give big effects. Angels Don't Play This HAARP cites an expert who says the military studied both lasers and chemicals which they figured could damage the ozone layer over an enemy. Looking at ways to cause earthquakes, as well as to detect them, was part of the project named Prime Argus, decades ago. The money for that came from the Defense Advanced Research Projects Agency (DARPA, now under the acronym ARPA.)
As far back as 1958, the chief White House advisor on weather modification, Captain Howard T. Orville, said the U.S. defense department was studying "ways to manipulate the charges of the earth and sky and so affect the weather" by using an electronic beam to ionize or de-ionize the atmosphere over a given area.
In 1966, Professor Gordon J. F. MacDonald was associate director of the Institute of Geophysics and Planetary Physics at the University of California, Los Angeles, was a member of the President's Science Advisory Committee, and later a member of the President's Council on Environmental Quality.
He published papers on the use of environmental-control technologies for military purposes. MacDonald made a revealing comment: "The key to geophysical warfare is the identification of environmental instabilities to which the addition of a small amount of energy would release vastly greater amounts of energy. "