The Washington times., 1918-08-25

phere, largely because of the water vapor
WHICH it contains, traps solar heat for the
whole planet. If there were no air sur
rounding the earth its surface at night
would be unendurably sold. and even by
day an icy temperature would prevail in
all shadows. The heat, even in full sun
shine would be radiated away so rapidly
that it could not penetrate to any depth
in the soil. On the other hand, if the heat
capturing power of the atmosphere could
be doubled or tripled the terrors of the
severest Winter would be warded of.
Experiments show that the power Of the
atmosphere to trap heat is largely due to
the water vapor that it contains. 1t is
also due 70 some extent, to the carbon
G;cxide gas that is one of its minor con-
stituents. Carbon diovide is a remarkable
heat retainer. but there is only a very
small quantity of it in the air compared
with the vast bulk Of the atmosphere. 1t
only amounts to about 3-lOOths of l per
cent But there is this significant fact
about IT, viz, that its amount is variable
10 a slight degree at the present time,
while there is evidence from past geo.
logical history that once it was vastly
more abundant than it is now.
Now how much carbon dioXide must
the air gain in order that perceptible
effect on the temperature may be pro-
duced? Arrhenius answers this question
for us He says that if all the carbon
dioxide now in the air were removed the
average temperature would fall nearly 81
degrees Fahrenheit. On the other hand,
amount wore dOublpd the
temperature would rise more than de-
grees. and. if it were quadrupled the rise
would amount to nearly 14l2 degrees.
which would be far more than enough TO
Danish all the glacial suffering that we
lad to endure last Winter. Even the
smaller amount of insrease q degrees)
would probably surfice for that.
But. granted all this, the question still
remains: Is it conceivable that man
could successfully interfere with so vas.
a concern of nature as the composition or
the air of the whole world? The answer
is. Yes: II is more than conceivable; It IS
nearly probable In fact. we have reason
TO believe that man has meaSurably altered
the constitution Of the air nv varying the
relative amounts of some of its consntu-
autS. lnd 1rhGt he has dOnc is erdcfV
the thing in question: ri-.. Increasing he
amount Of carbon dioridc.
II has been estimated that the burning
of coal in recent years has annually FUR
uished TO the atmosphere about OOOl66
ner cent Of the amount of carbon dioXide
that it normally contains. Then, in 600
wears the percentage of carbon dioxide will
be doubled. by the agency of man alone
provided that it all remains in the arr
Vegetation absorbs a great deal, but gives
most of il back again in roundabout ways
The sea absorbs a great deal but only
enough to maintain an equilibrium with
the air, so that the latter must retain a
certain proportion of its gain.
If human agency now adds carbon diox-
ide to the AR at such rate that the guam
tify will be doubled in 600 years, then, il
the annual supply were increased skiold
the doubline would be effected in 100 years
and if sixtyfold, in ten years. So here
we have a theoretical means of effecting
the needed change of climate; It shows
how il could be done. and how nature has
evidently done it in the past, but ii is
method that works too slowly. We cannot,
without fundamental discovery to aid u.s.
supply carbon dioxide fast enough to effec-
lively aid the present generation, nor the
next, nor the next.
To be sure, If we all worked together
TO pour into the air 600 times as much
Of this gas as we now do we should, ac-
cording to the calculations, double the at
mospheric percentage and bring about a
new climatic situation in a single year.
But, even if the coal mines could withstand
the drain, It would not be practicable to