278 CLOUD 



salts in ocean waters and those which occur in sediments and rocks beneath the 

 ocean floor. The dissolved salts, although vast in quantity, are thinly dispersed 

 and include only 64 of the 84 elements now in commercial use, among them 

 very few metals. Only 15 of these elements are found in quantities of more than 

 1 lb per million gallons and only 9 of these 15 are found in values of more than 

 $10 per million gallons. Candidly, seawater is more of an arithmetic trap than a 

 horn of plenty. 



When it comes to marine resources in sediments and rocks beneath the water 

 column, we again have to think of two main realms. One realm is that of the 

 continental shelves and slopes which belong properly to the continents and 

 which have about the same prospects of resource production as a similar area on 

 the continents, particularly for oil. An increasing portion of our domestic oil 

 resources will come from the continental shelves. The other realm, by far the 

 greater part of the ocean floor, is that of the truly oceanic basins, which are 

 underlain by entirely different kinds of rocks and sediments. These truly oceanic 

 deposits are characterized most importantly by relatively young basic (mafic) 

 volcanic rocks, poor in metalliferous content and moving at rates of a few 

 centimeters per year away from the ocean centers to disappear eventually 

 beneath the continents — the deep ocean floor is everywhere young, limited in 

 variety of metals, and, at most places, sparsely metalliferous. Marine resources, 

 although they may make a few people rich and will certainly produce some 

 useful resources, will not go far toward reducing the main crunch. 



Finally, and simply because it comes up so often, I must comment briefly on 

 other planets as abodes for surplus population or for procurement of mineral 

 resources. Is there any validity at all to the view that when Earth becomes too 

 desperately overloaded, we can ship surplus population off to Mars and other 

 planets, or possibly to the moons of Jupiter? Leaving aside the problems of 

 choosing who might go and how living conditions are up there, we have to bear 

 in mind that the present population of the earth is increasing by about 78 

 million a year, a number equivalent to about 37% of the total population of the 

 United States at the present time. What logistic and financial problems are 

 involved in shipping 78 million or more people a year to other planets? Hardin 

 (1959) calculated that it would take three-fourths of the U. S. annual GNP to 

 ship one day's increase in world population to other planets. The problem of 

 returning raw or refined mineral products from other planets to Earth, assuming 

 they are found, is of comparable dimensions. 



It is clear, when we look at the above-mentioned and other limiting factors 

 simultaneously, that the real question is not whether a balance with nature will 

 be restored; that it will be is assured by Le Chatelier's principle. The real and 

 pressing question is whether a new and more durable balance with nature will 

 result from thoughtful assessments, decisions, and actions on our part, or 

 whether that balance will come about through harsh but inexorable natural 

 processes over which we have no control. Essential elements in the establishment 

 of balance favorable to ourselves and our descendants include, first and 



