Page 191 - For Men of Understanding

quicker and rocks and metals would be eroded sooner. Hence, the earth would
be eroded and disintegrate, and animate life would face a great threat. If we
had a little less oxygen, respiration would become harder, and less of the
ozone gas would be produced. Changes in the amount of ozone would be fatal
for life. Less ozone would cause the solar ultra-violet rays to reach the world
in greater intensity causing living things to vanish. More ozone would prevent
the sun’s heat reaching the earth and thus be fatal.
Carbon dioxide has similar delicate balances. Plants absorb the sun’s radia-
tion via this gas, mix it with water, form bicarbonate that dissolves rocks, and
leave it in oceans. They also break this gas down and release oxygen back into
the atmosphere. Thus, oxygen, an essential for living beings, is constantly
released into the atmosphere. This gas also helps the world maintain a "green-
house effect" keeping its present temperature constant.
If there were less carbon dioxide, the amount of plant-life on land and in
the sea would be reduced, leaving less food for animals. There would be less
bicarbonate in the oceans, thus causing an increase in acidity. An increase in
carbon dioxide in the atmosphere would expedite the
chemical erosion of land forming a detrimental alkali
How many signs
residue in oceans. In addition, the greenhouse effect
there are in the
would increase, thus causing the surface temperature of
heavens and earth!
the earth to rise and life on earth to be destroyed.
Yet they pass them
As seen, the existence of the atmosphere has great
by, turning away
importance for the continuation of life on earth. A num-
from them.
ber of astrophysical conditions have to co-exist for the
(Surah Yusuf: 105)
atmosphere to be maintained.

A) The earth’s surface has to remain at a certain moderate
temperature, within definite limits. For this:

1. The earth has to be a certain distance from the sun. This distance plays
a role in the quantity of heat energy reaching the earth from the sun. A slight
deviation in the earth’s orbit around the sun – either drawing closer or farther
– would cause great changes in the heat reaching the earth from the sun.
Calculations show that a 13% decrease in the heat reaching the earth would
cause it to be covered with an ice layer 1,000 metres thick. A slight increase in
energy, on the other hand, would cause all living things to be scorched.
2. The temperature should be homogeneous across the earth. For this, the
world has to rotate about its axis at a certain speed (1,670 km/hr at the equa-
tor). If the earth’s speed of rotation were to exceed a certain limit, the atmos-
phere would grow extremely warm, increasing the gas molecules’ velocity of

The Earth 189