ABSTRACT
Grain produced in the US constitutes a large fraction of available food in the world export market. Some scientists have forecast expanded drought conditions throughout the last of the 1970s, perhaps even as a consequence of pollution. Although natural climatic variability can be expected to continue with a high degree of certainty and a low degree of specific predictability, it still may be possible for climatologists to provide useful input in the planning process. A problem for the scientist wishing to establish the sensitivity of the climatic system to an external perturbation relates to the time delay involved in establishing the detectability of the perturbation. Geophysical processes have certain inherent time constants associated with them, which may be as short as a fraction of a second or as long as millennia. Society may need to plan for climatic events like droughts that can be deemed only probable.
