WMOD00398 - Laserfiche WebLink

Home Browse Search

The range of possible ecological consequences to be considered was broadened with concern voiced about silver iodide as a cloud seeding agent. Inspired by a staff paper citing toxicity standards of various materials handled by cloud seeders [5], a law professor in Arizona speculated [4] that despite extremely low concentration of these materials once they mix with the atmosphere, and despite scientific attitudes respecting their harmlessness, "there may be legal and perhaps legislative consequences to putting any quantity of poison in the atmosphere. In effect, a nonsophisticated public will create 'political causation'." A Pennsylvania judge promptly confirmed this speculation by ruling that the poisonous character of cloud seeding agents made cloud seeding subject to prohibition by local public health authorities as a menace to health [10]. Soon thereafter, a problem analysis [3] called attention to the possible direct effects of silver iodide used as a cloud seeding agent. Although thi~ report found little likelihood of adverse effect on terrestrial or marine environments, it pointed to the possibility that silver from silver iodide might selectively inhibit the growth of certain freshwater microorganisms or interfere with biological decomposition of bottom sediments. From these beginnings, concern over silver mushroomed rapidly. Skywater IX was organized into six working groups whose topics corresponded to the way the ecology projects have been divided. For each group, the Division of Atmospheric Water Resources Management appointed a convener, who in turn selected four or five collegues. A resource person was assigned from the Skywater staff to each group to answer questions that might arise about the program, The participants were asked to address primarily the issues of long-term environmental impacts that would be raised if the application of the technologies of winter-orographic and summer-convective precipitation augmentation (now the focus of the Skywater developmental effort) were to become widespread and prolonged, It was to be assumed that median precipitation amounts in these classes would be increased by 15 percent or less, depending upon intensity of application and technological success, with little or no operation to be expected during periods of naturally above-normal precipitation. Suggested issues were laid before each of the six groups corresponding to subjects of potential importance that had not been resolved by work completed to date. These issues were: Abiotic processes.-What abiotic components of the environment will precipitation management affect, and how much? What proportion of the variations they are likely to undergo may be related to precipitation management, and to what extent will the precipitation-management-related disturbances be distinguishable from those otherwise caused? What linkages transmit precipitation-management impacts from one abiotic component to another, and to vegetable, animal, and socioeconomic compartments? How may important abiotic factors be efficiently characterized, parameterized, and indexed? How can erosion be related to precipitation management to include both its direct effects and its indirect effects through vegetation, development, etc.? What about alluviation? Are there important in-channel effects? Vegetation.-How should attention be, balanced between specific impacts, that is, on certain \ crops or forage areas, and general principles governing vegetation processes? Are there particular index species that may be representative of large groupings? How do vegetational provinces differ from one another in ways important to precipitation-management impacts? 2- '7 ., ~~ ?