lems. Ways to conserve
and reuse water, together with economical desalting of sea water, will
be essential in the decades ahead. Space research may provide part of
the answer here, too. (See New Water Sources and Uses, sec. III.)

_Soil erosion_

The Russian steppes of Kazakhstan are providing the world with a great
contemporary dust bowl, reminiscent of the middle 1930's when dust from
the Great Plains stretched from Texas to Saskatchewan. Questionable
agriculture policies, drought, and strong easterly winds are among the
forces blamed for the trials of southern Russia.[74] So great is the
extent of this disturbance that the dust cloud has been identified in
photographs taken by American weather satellites.

Of course, "wind erosion is only one of the processes whereby the
Earth's arable land is diminishing and the deserts increasing; erosion
by water can also sweep away the soil."[75] But insofar as the current
dust bowl of the Soviet steppes has "diminished food resources at a time
when the number of mouths to feed is increasing so rapidly, the world is
the poorer."[76]

What can space research do about this vital trend, which again seems
destined to accelerate in the future?

While we cannot be sure, we can conjecture that improved soil
conservation might turn out to be the greatest benefit of weather
understanding and modification. Agriculture policies might be adapted to
the long-range patterns uncovered by weather satellites and, eventually,
through better understanding of the making of weather, it may be
possible to modify weather forces in a manner which will preserve the
soil.

In a more remote vein, it may be that knowledge gained from a first-hand
study of the Moon or other planets in the solar system will eventually
contribute to the conservation of soil on Earth in ways as yet
unimagined.

_Added leisure_

Acquiring more time for leisure sounds good. Very much more leisure than
most people now have, however, is apt to present trouble in itself.
Since it appears that the time is not far away when those living in the
highly developed countries will no longer have to concentrate their
prime energies on the traditional quest for food, clothing, and shelter,
a potentially dangerous vacuum may be the result. At least the
psychologists seem agreed that people must feel a useful purpose in
their lives and have ways to pursue it.

Above all, leisure makes a challenge to the human spirit. Athens