260 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
The quantity of solar energy used in driving the engine of the sea 
and the atmosphere is so great compared to any of the energy 
sources under man’s control that it would seem impossible for us 
to affect weather or climate materially by any human action. Yet, 
a close look shows there may be some things we could do. Many of 
the processes in the atmosphere are metastable: a slight action may 
initiate a very large-scale process. We might learn how to regulate 
climate if we could find the right lever to pull. 
One may predict that with the coming of greater understanding, 
promising methods for contro] of weather and climate will be found. 
The average reflectivity of the ground surface over the large areas 
might be reduced, for example, by rapid melting of the snow cover, 
thus increasing the percentage of sunlight absorbed. On the other 
hand, it might be possible to shut off some of the sun’s radiation 
before it reaches the earth’s surface, for example, by injecting a small 
amount of absorbing or reflecting substances into the upper atmos- 
phere. 
GREAT EXPERIMENT 
During our lifetime we may be witnessing an example of one way 
in which human actions can affect weather and climate. Since the 
beginning of the industrial revolution, an amount of carbon dioxide 
equal to about 12 percent of the total already present in the atmosphere 
has been produced by the burning of coal, oil, and natural gas. The 
ability of the ocean to absorb carbon dioxide is very great and prob- 
ably most of the amount added to the atmosphere during the last 
century has gone into the sea. During the next hundred years, how- 
ever, the increasing use of fossil fuels in our worldwide industrial 
civilization should result in the production of about 1,700 billion tons 
of carbon dioxide—70 percent of the amount now in the atmosphere. 
Because of the rapid increase in the production rate, the fraction of 
the added carbon dioxide absorbed by the ocean will be lessened and 
an increase of perhaps 20 percent in atmospheric carbon dioxide can 
be expected. The effect of such an increase is not easy to predict, 
but there is some theoretical reason to believe that it could result in 
a warming of the lower atmosphere by several degrees. Thus, by 
consuming within a few generations the fossil fuels laid down in 
sedimentary rocks over many hundreds of millions of years, we are 
conducting, more or less in spite of ourselves, a great geophysical 
experiment. It is of vital importance to keep accurate records of 
this experiment in order to increase our understanding of the mecha- 
nisms controlling climate. With this in mind, careful measurements 
will be made during the IGY of the carbon dioxide content of the 
atmosphere, and studies will be initiated to refine our estimates of 
the absorption of carbon dioxide in the sea. 
