IMPORTANCE OF THE ATMOSPHERE FOR LIVING BEINGS - ENVIRONMENT - 2025

The importance of the atmosphere is such that if it were suddenly missing, life would cease to exist as we know it. Although we are rarely aware of what it represents to us, the truth is that without it we would not be here.

The atmosphere makes life easier and protects the planet. It had its origin with the planet itself, approximately 4.6 billion years ago, although its composition then is not the same as it is now.

Layers of the atmosphere. Source: Wikimedia Commons.

The early atmosphere was extremely dense, due to gases that continually escaped from the interior of the newly formed Earth, abundant in hydrogen, water vapor, methane, helium, hydrogen, sulfur, carbon monoxide and dioxide.

However, without its own magnetic field, the solar wind, that tide of charged particles that the Sun continuously radiates, was in charge of sweeping away the molecules that made up the primitive atmosphere. In this way light gases such as hydrogen and helium escaped.

When the aquatic masses began to appear, new compounds were formed that when reacting with the rocks, gave rise to gases such as methane and ammonia.

As it cooled, the Earth continued to expel new gases until it created an atmospheric composition more similar to the current one, with nitrogen, oxygen, carbon dioxide and water vapor.

Finally, with the arrival of the first bacteria, about 3.5 billion years ago, the proportion of oxygen increased. And with it came new organisms of greater size and complexity.

Why is atmosphere important?

1.- It is the basis of life on Earth

Living beings are adapted to breathe the mixture of gases that make up the atmosphere, and as we have said, the presence of oxygen has been vital for the development of life.

The oxygen present in the atmosphere is necessary for the maintenance of cellular functions, both in animals and plants. And for these, carbon dioxide is essential to carry out photosynthesis.

2.- Protect the planet from the impact of meteors

The atmosphere prevents large space visitors with destructive intent from reaching the Earth's surface. Indeed, the friction force generated between the surface of the meteors and the molecules of the atmosphere is strong enough to disintegrate them by combustion.

In addition, new simulations indicate that the dynamics between the airflow and the meteor moving at high speed, is capable of causing the gaseous molecules to enter with great pressure through the cracks in the rock and fragment it before it reaches the surface.

3.- Regulate the climate and temperature

The atmosphere prevents too much heat from being lost during the night and also that during the day the sun's rays burn directly to the earth's surface. Without the atmosphere, the temperature on Earth would undergo very abrupt changes.

Some of the gases that make up the atmosphere, such as carbon dioxide, are capable of retaining heat, as a mild greenhouse effect. In this way the temperature does not drop sharply. By absorbing a good part of the solar radiation that arrives during the day, excessive heating of the surface is avoided.

Since in this way the atmosphere prevents extreme temperature variations, the global average for the planet remains at 15 ºC, but if the atmosphere did not exist, it is estimated that there would be changes so extreme as to give rise to an average of -18 ºC.

On the other hand, climatic processes take place in the atmosphere: clouds, rain, winds and other manifestations of the climate. The water cycle occurs in the atmosphere: water evaporates and water vapor rises and cools, then condenses and forms clouds.

A large amount of water condensed in the clouds produces rain and in this way the water returns to the earth to start a new cycle.

4.- It makes possible the transmission of sound

Airplane breaking the sound barrier

Sound is essential for the communication of many species, including of course humans. The variety of sounds in nature is amazing, and on the other hand music is one of the highest expressions of humanity.

We rarely stop to think that thanks to the atmosphere we can enjoy all of this, since sound is a longitudinal mechanical wave that requires a material medium - air molecules or other medium - to propagate.

The sound waves make the air molecules vibrate and this vibration reaches the eardrum, travels to the brain thanks to the auditory nerve and is conveniently interpreted there. The depths of space are completely silent, as there is no atmosphere there to make sound propagate.

5.- Facilitates combustion

Fire has been one of the great discoveries of humanity, which facilitated its evolution.

Well, combustion is only possible in the presence of oxygen, and the earth's atmosphere has enough to create good fires that allowed primitive human beings, like those of today, to cook their meals, protect themselves from predators, from the cold and create new tools and utensils.

6.- It works as a solar screen

Earth and its atmosphere, seen from space. Source: Pixabay.

In addition to the light and heat that we appreciate so much, the Sun produces other less benevolent radiation. The atmosphere protects to a large extent from harmful radiation such as ultraviolet rays and others of higher energy that the Sun also sends, such as X-rays and gamma rays.

Part of this radiation is absorbed and reflected by the upper layers of the atmosphere and by the ozone layer. So much so that the appearance of the ozone layer facilitated the migration of living organisms from the seas to the mainland.

7.- Continuously model the land surface

Without the atmosphere we would not know the variety of landscapes that currently exist on the planet. Wind and rain, products of atmospheric activity, are responsible for shaping all kinds of landscapes.

Rocks change their shape thanks to wear and tear caused by weathering. The sand particles, driven by the wind, erode the surface like sandpaper. For its part, rainwater seeps into tiny cracks in the rocks and slowly dissolves them.

References

1. Aguilar, A. 2004. General Geography.2da. Edition. Prentice Hall.
2. Gonzalez C. Rubén. Formation and evolution of the Earth's atmosphere. Recovered from: cienciorama.unam.mx.
3. CK-12 Foundation. The importance of the atmosphere. Recovered from: ck12.org.
4. Román, V. The Earth's atmosphere destroys meteors from within. Recovered from: nmas1.org.
5. Wikipedia. Earth's atmosphere. Recovered from: es.wikipedia.org.