methodological problems must be overcome, however, before these 

 and similar approaches can provide reliable, early-warning signals of 

 impending threats. 



It is clear that environmental problems are often not exclusively 

 scientific in character, in that they involve human values and economic 

 and social considerations, as well as scientific knowledge. The 

 aesthetic value of wild landscapes or the desirability of urban open 

 space illustrates this characteristic. Science can provide understanding 

 and alternatives based on knowledge, but society must choose from 

 among the alternatives based on th^^relative importance it attaches to 

 the values affected. 



General References 



Patterns and Perspectives in Environmental Science, National Science Foundation, U.S. 

 Government Printing Office, Washington, D.C., 1972. 



Man's Impact on the Global Environment, Assessment and Recommendation for Action, MIT 

 Press, 1970. 



The Challenges in Perspective 



The primeval challenge of the unknown and a multitude of 

 challenges of the natural environment still confront us. Social 

 problems, though greatly changed, still persist and in some ways have 

 intensified in recent years. But it is the challenges created by man's 

 increasing power to shape the future that are escalating most 

 dramatically. 



Because of the interdependences characterizing the modern 

 world and because of the rapid rates of change, challenges such as 

 those outlined are becoming more difficult to cope with — difficult both 

 for society at large and for the scientific community. 

 Interdependencies strain the capacities of organizations and decision 

 processes. Problems now cut across the organizational and 

 jurisdictional boundaries that were more or less congruent with 

 problems in the past. Informed decisions now require assessment of a 

 multitude of ramifications and interactions, but the extensive 

 knowledge and understanding needed for these assessments are not 

 always available, nor are institutional incentives always present to 

 encourage such assessments. 



Rapid rates of change place additional burdens on organizations 

 and decision processes. Rapid change, while diminishing the 

 opportunity to look ahead, multiplies the knowledge required for 

 reliable insights into the future. Rapid change also reduces the 

 relevance of precedent, of custom, of traditional values, and of 

 conventional wisdom as guides for decision. As the rate of change 

 quickens, society's decisions and rules must either be continuously 



28 



