ote ANNUAL REPORT SMITHSONIAN INSTITUTION, 1959 
and outward radiation and the transfer of heat to the atmosphere 
have their main effect at the surface, and this cannot produce very 
active convection. It has been estimated that the kinetic energy in the 
oceans is only about 2 percent of what it is in the atmosphere, and that 
most of this small fraction is derived from the atmosphere through the 
drag of the wind. But although the water movements are slow, they 
carry large amounts of heat and do much to determine the place at 
which most heat is fed to the atmosphere. In this way they influence 
cloudiness, the radiation balance, and winds. Winds and currents also 
influence the density layering in the ocean, and this in turn affects the 
response of the water to the wind and to differences in climate. 
The interrelation of all these factors is too complex to be easily 
understood, but more and more emphasis is being placed on the need 
for comprehensive study. The lower atmosphere gets most of its heat 
from the sea, and a fuller understanding of the processes involved is 
needed to improve methods of forecasting warm, cold, wet, and dry 
periods for the benefit of food growers. Such knowledge may be use- 
ful in studies of weather as well as of climate, particularly in predict- 
ing hurricanes and typhoons, which all start over the ocean. It is 
also needed with respect to the oceans themselves—to enable fisheries 
scientists to predict how changes in wind and climate are likely to 
affect the water conditions in a fishing ground; and in the shorter run, 
to enable navigators to judge how particular wind conditions will 
affect a current. 
The study of long-term trends in climate based on biological, geo- 
logical, and archeological evidence is of interest to many branches of 
science—and has also some more immediate practical importance. 
The question of sea level is one example, since it is important to know 
whether the present rising trend is likely to continue. Another inter- 
esting example is the question of the average carbon dioxide content 
of the atmosphere; there is a possibility that this content is being 
increased by the growing expansion of industrial processes. The idea 
was previously dismissed on the grounds that the part played by 
carbon dioxide in absorbing the longwave radiation sent out by the 
earth was small compared with that of water vapor, and that in any 
case the carbon dioxide content of the atmosphere was controlled by 
the oceans, which have an almost infinite capacity for taking it into 
chemical combination as well as into solution. New estimates have 
revived the discussion, the idea being that by our present enormous 
consumption of coal and oil we are building a more effective green- 
house roof over our heads. This and other theories have been put 
forward to account for historical climatic changes. The idea must be 
given careful consideration, since a significant rise in the mean tem- 
perature would mean a reduction in ice cover of the arctic and antarctic 
