SUN, SEA, AND AIR—-REVELLE 259 
same amount of energy would raise the average temperature of the 
ocean by only a little more than 1° C. (On the other hand, the melt- 
ing of ice caps would be somewhat more obvious to everyone, since it 
would result in a rise of sea level by at least 200 feet, and the conse- 
quent destruction of most of the world’s largest cities!) 
Because of the great heat capacity of the ocean, many meteorolo- 
gists and oceanographers now believe that climatic changes lasting 
over decades or centuries may be intimately related to changes in 
the circulation of the deep sea. Effective techniques for studying this 
circulation have become available only in the last few years, and it 
is little understood. We know that cold water sinks to great depths 
from the surface in high latitudes, moves slowly toward the Equator 
and perhaps across it, and returns by an unknown path to the start- 
ing point. The time required for the round trip is not known; it 
may be measured in decades or millennia. Nor do we know whether 
the circulation is steady or intermittent like the flushing of water in 
a bowl. 
One of the major enterprises of the International Geophysical 
Year will be a series of great oceanographic expeditions, conducted 
by 70 ships belonging to many countries. Their principal objective 
will be to obtain a comprehensive picture of the temperature and 
other properties of the deep sea waters, and to make direct and in- 
direct measurements of their motions. 
THE EARTH AND MAN 
President Eisenhower has said that water is rapidly becoming our 
most critical natural resource. During the last few years, serious 
attempts have been made to develop inexpensive machines for convert- 
ing sea water into fresh water. The fact is, of course, that nature 
herself operates a most effective distillation system. Nearly one-third 
of all the energy of sunlight falling on the sea surface is utilized in 
converting sea water to fresh water by evaporation. The immense 
quantity of solar power used in this way is several thousand times 
all the power produced by our industrial society from hydroelectric 
power and the burning of coal, oil, and natural gas. 
The total quantity of water evaporated, if all of it fell on the 
surface of the land and was uniformly distributed, would result in 
an average rainfall of over 100 inches a year. Evidently the trouble 
with the natural distillation process is not the quantity of fresh 
water produced, but rather that nature’s pipelines are badly placed. 
Too much water moves to some areas and not enough to others; more- 
over, the valve system seems to be capriciously managed. Sometimes 
the discharge is too great, bringing floods, while at other lines there is 
only a trickle and droughts occur. 
Can anything be done about this faulty distribution system ? 
