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the time was ripe for organizing a new international program to 

 study global change, employing all the knowledge and resources 

 developed since the IGY in an integrated study of the entire 

 sun-earth system. Preliminary discussions in the world 

 scientific community have led to substantial enthusiasm for such 

 a program with a long range format and proper integration of 

 both biological and geophysical components. In the U.S., the 

 name International Geosphere-Biosphere Program was adopted; 

 geosphere to represent all of the disciplinary areas of the 

 earth sciences — lithosphere, hydrosphere, atmosphere, 

 ionosphere, magnetosphere, etc. — and biosphere describing the 

 thin film of living environment that envelopes the surface of 

 the earth. 



In recent years, questions related to acid rain, greenhouse 

 gases, ozone and atmospheric pollutants and all of the elements 

 that control climate have received intensive scientific and 

 political consideration. The contemporary concern for the 

 environment has focused new attention on biogeochemical cycles 

 and the various links between geophysical and biospheric 

 processes. To understand changing conditions for life on earth 

 and the role of human activities calls for urgent attention to 

 developing the basic scientific knowledge of the geosphere and 

 biosphere. A sound knowledge base must include a comprehensive 

 understanding of the historical evolution of the earth and the 

 dynamics of global change as they are written in the geological 

 record. 



