PRECISE THINGS THAT SHOW HOW PRECARIOUS LIFE REALLY IS

TROPOSPHERIC OZONE

We begin this list with the tropospheric ozone. In simple

terms, the tropospheric ozone is ground-level ozone.

As it currently stands, if it were to increase in quantity,

animals would experience respiratory failure. It would also

hinder crop yields and ozone-sensitive species would die.

However, if it were smaller, biochemical smog would

destroy most life.

OUR GALAXY’S SHAPE

Galaxies come in roughly four shapes: spiral, elliptical,

lenticular, and irregular. The Milky Way galaxy is a prime

example of a spiral galaxy though there are many more

spiral galaxies out there. Our case as of this moment is

unique as we are the only galaxy (so far) known to harbour

life. If our galaxy was too elliptical, then the formation of

stars would cease before sufficient amounts of heavy

elements had the chance to form and create life chemistry.

On the other hand, if our galaxy’s shape was too

irregular, then we would have been exposed to harsh

radiation which would inhibit the formation of

life-essential heavy elements.

THE FREQUENCY AND EXTENT OF ICE AGES

This may sound a bit odd but it’s believed that if there were

no ice ages or even fewer than what have occurred then Earth’s

surface would lack fertile valleys, essential for advanced life.

Moreover, mineral concentrations would be insufficient as well.

On the other hand, if ice ages had been more frequent, then

Earth would experience freezing temperatures that

wouldn’t allow for any form of intelligent life.

THE DISTRIBUTION OF CONTINENTS

Even the distribution of our continents have a direct impact

on life as we know it. If our continents were distributed

more towards the southern hemisphere, then sea salt

aerosols would not be enough to stabilize our planet’s

surface temperature and the water cycle. As a result,

“increased seasonal differences would limit the

available habitats for advanced land life”.

EARTH’S ATMOSPHERIC PRESSURE

Our atmosphere is responsible for containing the air necessary

for life and it also protects us from the harmful radiation

emitted by the sun. Earth’s atmosphere is about 300 miles

thick (but most of it is within 10 miles from the surface). The

further up in the atmosphere you go, the less air pressure there

is. For example, at sea level, air pressure is about 14.7

pounds per square inch, and at 10,000 feet, air pressure

is 10 pounds per square inch. If there was less atmospheric

pressure, liquid water would evaporate too easily and

condense too infrequently to support life. However, if air

pressure was greater, the opposite would be true, there

would be inadequate liquid water evaporation to support

life. Furthermore, not enough sunlight and UV radiation

would reach Earth’s surface.

OUR PLANET'S “ELECTRICITY”

Many people are killed by lightning annually worldwide.

But lightning may be a key to the origin of life. With water,

methane, and other chemicals in the atmosphere, lightning

can create amino acids and sugars that are the building

blocks of life. In 1953 the well-known Miller-Urey experiment

raised the possibility that lightning may have been

a key to life’s origins.

TEMPERATE ZONES

Some life has adapted to the most frigid places on Earth

including Antarctica, where the planet’s record low was

set at minus 128.6 degrees Fahrenheit, or minus 89.2

degrees Celsius and its hottest deserts. But life achieves

its greatest diversity in more temperate climates,

namely the tropics.

PROPER SEISMIC ACTIVITY

According to science, if there were no earthquakes then

nutrients on the ocean floor from river runoff would not be

recycled to continents through tectonics; not enough carbon

dioxide would be released from carbonate build up and

life would become hard to maintain.

PERFECT TIMING OF SOLAR NEBULA FORMATION

RELATIVE TO SUPERNOVA ERUPTION

If the timing of solar nebula formation relative to supernova

eruption occurred earlier, nebula would be blown apart.

If it happened later, nebula would not attract enough

heavy elements for life chemistry.