Worldwide, economic damages attributed to natural disasters tripled from the 1960s (US$40 billion) to the 1980s (US$120 billion) (Domeisen 1995). The 1990s have witnessed a continued escalation of economic damages, reaching US$400 billion through 1996 (Carolwicz 1996). Between 1992 and 1996, losses associated with natural disasters in the United States averaged US$54.2 billion per week (Carolwicz 1996). The economic, social, and environmental costs and losses associated with drought are also increasing dramatically, although it is difficult to quantify this trend precisely because of the lack of reliable historical estimates of losses. White and Haas estimated in 1975 that the average annual crop losses associated with drought in the Great Plains region of the United States were about US$700 million. In 1995, the US Federal Emergency Management Agency (FEMA) estimated annual losses attributable to drought at US$6-8 billion (FEMA 1995).