PEOPLE HAVE different ideas about what the atmosphere is and what it is made up of. This week, we will take a closer look at the earth’s atmosphere, some of the changes that are occurring in it, and what we can do to help address or adjust to those changes.

What is the atmosphere?
The atmosphere is a thin layer of gases that surrounds the earth and is retained by gravity. The atmosphere is a moving source of life for every creature on earth, and it protects the earth from the vacuum and radiation of space.

The most abundant gas in the atmosphere is nitrogen (N2), but it also contains other gases, such as oxygen (O2) and carbon dioxide (CO2) (which plants and animals need to survive), argon, water vapour and trace amounts of other gases. The atmosphere has specialized molecules like ozone (O3) that filter out harmful radiation from space. Without the atmosphere, the earth would be unable to sustain life.

Layers of the earth’s Atmosphere
There is no definite boundary between the atmosphere and Outer Space, as it slowly becomes thinner and fades into, or merges with, space. The atmosphere is divided into five (5) layers:

The Troposphere: This is the first layer above the surface of the earth, and it contains half of the earth’s atmosphere. It is in this layer that weather occurs.

The Stratosphere: Many jet aircrafts fly in the stratosphere because it is very stable. Also, the Ozone Layer, which absorbs harmful rays from the Sun, is found here.

The Mesosphere: Meteors or rock fragments burn up in this layer.

The Thermosphere: This is a layer with auroras. It is also where the space shuttle orbits.

The atmosphere merges into space in the extremely thin Exosphere. This is the upper limit of our atmosphere.

The layers of the atmosphere interact, heat up, and interact with the top layer of the earth’s crust. Sometimes you feel the atmosphere as a cool breeze; sometimes it is really hot and humid.

Importance of the atmosphere
The atmosphere plays a crucial role in maintaining life on earth and without it, life would be impossible. It gives us air to breathe and protects us from meteorites and ultraviolet rays from the sun. The atmosphere absorbs so much heat, that the temperature on earth makes it possible for living things to exist.

The atmosphere is also vital in creating climates. Different climates result from circulation of gases and particles in the atmosphere; hence there is not one climate for the whole planet. Different climates are found in various areas all over the planet.

The hot air from the equator eventually moves north or south to other climates. The warmer air combines with cooler air and mixing begins (and storms formed). The constant mixing of the atmosphere helps to keep a stable system for the organisms of this planet to survive.

Today, our atmosphere is being destroyed because of the harmful chemicals which are emitted daily through human activities. This also has some significant impacts on the temperatures and climate of the earth. Let us therefore, examine our actions and see how we can help to preserve our precious atmosphere and ultimately life on earth.

You can help protect our atmosphere
You can make a positive contribution to help to protect the Atmosphere. Simple things such as proper ventilation, using energy-efficient appliances, allocating proper storage facilities for paints, cleaners, and pesticides, minimizing or avoiding emissions from candles, cigarettes, barbecues, opening windows and planting trees can go a long way in helping to ensure good air quality.

Remember, small changes can make a big difference. Do your part for a better environment!

Sources: En.wikipedia.org/wiki
Csep10.phys.utk.edu
http://mediatheek.thinkquest

You can also share your ideas and questions by sending your letters to: ‘Our Environment’, C/o EIT Division. The Environmental Protection Agency, 7 Broad and Charles Streets, Charlestown, GEORGETOWN. Or email us at eit.epaguyana@gmail.com with your questions and comments.