The Earth's Shifting Crust by Charles Hapgood - wire of information

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EARTH'S SHIFTING CRUST
the parent assumption, that is, the assumption of the lower-
ing of global temperatures during ice ages, which assumption
is, as already pointed out, in conflict with the laws of physics.
If it is true that the fundamental assumption underlying
most of the theories produced to explain ice ages is in error,
we should expect that these theories, despite their many
differences, would have a common quality of futility, and so
it turns out. It is interesting to list the kinds of hypothetical
causes that have been suggested to explain ice ages on the
assumption of a world-wide lowering of temperature. They
are as follows:
a. Variations in the quantity of particle emission and of
the radiant heat given off by the sun.
b. Interception of part of the sun's radiation by clouds
of interstellar gas or dust.
c. Variations in the heat of space; that is, the temperature
of particles floating in space which, entering the earth's
atmosphere, might affect its temperature.
d. Variations in the quantities of dust particles in the at-
mosphere, from volcanic eruptions or other causes, or
variations in proportion of carbon dioxide in the at-
mosphere.
The objections to these suggestions are all very cogent. So
far as the variation of the sun's radiation is concerned, it is
known that it varies slightly over short periods, but there is
no evidence that it has ever varied enough, or for a long
enough time, to cause an ice age. Evidence for the second and
third suggestions is entirely lacking. The fourth suggestion is
deprived of value because, on the one hand, no causes can
be suggested for long-term changes in the number of erup-
tions or in the atmospheric proportion of carbon dioxide,
and, on the other, there is insufficient evidence to show that
the changes ever occurred.
I should make one reservation with regard to the fourth
suggestion. There is one event that would provide an ade-
quate cause for an increase in the atmosphere of both vol-