For nearly two decades vigorous research in weather modification was carried out in the United States and elsewhere. As shown in Fig. 3.1, federal funding in the United States for weather modification research peaked in the middle 1970s at nearly $19 million per year. Even at its peak, funding for weather modification research was only 6% of the total federal spending in atmospheric research (Changnon and Lambright, 1987) and this amount included considerable support for basic research on the physics of clouds and of tropical cyclones. Nonetheless, research funding in cloud physics, cloud dynamics, and mesoscale meteorology was largely justified based on its application to development of the technology of weather modification. Research on the basic microphysics of clouds particularly benefited from the political and social support for weather modification.

By 1980, the funding levels in weather modification research began to fall appreciably and by 1985 they had fallen to the level of $12 million. After 1985, funding in weather modification research became so small and fragmented that no federal agency kept track of it. Currently the Bureau of Reclamation has only about $0.25 million per year that can be identified as weather modification. They have operated a program in Thailand that was supported by the Agency for International Development. Basic research in the National Science Foundation that can be linked to weather modification is on the order of $1 million.