2. Conserving Our Resources
The Atmosphere Protects Us
Conserving Our Resources
Ministry of Education
B.E.S.T.
Bahamas Education School Technology Project
P.O. Box N3919
Nassau, Bahamas

3. Objectives Identify the layers of the atmosphere
Define the term ‘acid rain’
Explain the ‘greenhouse effect’
Outline the effects of the thinning of the ozone layer
Formulate a list of laws that can be made to assist in protecting the atmosphere.

4. Vocabulary Atmosphere – blanket of gases that surrounds the Earth
fossil fuels – natural resources for example, coal, oil and gas, that are made from animals and plants that lived long ago
acid rain – rain that has been polluted by various gases
Photosynthesis – the way in which green plants while making food release oxygen, using carbon dioxide and sunlight
global warming – the warming up of the Earth’s atmosphere
Stratosphere – one of the layers of the atmosphere

5. What is atmosphere? The Earth is surrounded by several layers which together are called the atmosphere.
It surrounds the Earth completely and is about 900 kilometers thick.
A blanket of air is held close to the Earth by the force of gravity.
Without it there would be no air for us to breathe in. All living things would die.
There would be no wind. The whole world would be silent and dead.
Heat and light from the sun are necessary to all forms of life. The atmosphere stores heat, protects us from the bitter cold of outer space, and shields us from the Sun’s harmful ultraviolet radiation

6. SUN
The Earth’s atmosphere allows heat and light from the sun to pass through, but protects people from harmful radiation
EARTH

7. Polluting The Atmosphere
Clean air is essential to healthy life. In some places in the world, the air is so polluted that it is not safe to breathe.
How does the atmosphere become polluted? When fuel is burned, it releases harmful wastes in the form of gases. These come from factories and also from things made in factories, like cars. This polluted air spreads out into the atmosphere and does not disappear.

8. Acid Rain
The atmosphere over many cities around the world is heavily polluted with various substances, many of them harmful. When fossil fuels (coal, oil and gas) are burned in factories, power stations and motor vehicles, they produce sulphur and nitrogen. These react with water in the air to make sulphuric and nitric acids. The resulting acid rain may fall far away from the place where the gases were produced. Acid rain is a major pollution problem in Europe and North America.

9. Acid Rain
High
Medium
Low
None

10. All rain contains some weak acids, because the water reacts with the gases that occur naturally in the air.
But in recent years the rain has become more and more acid, and it is now damaging buildings, crops, trees and wildlife.

11. Trees and other plants use sunlight to make food by a process called photosynthesis.
They produce oxygen by this process, which is important to animals because they need oxygen to breathe.
Acid rain damages the leaves of plants so they can no longer make the food they need, or produce oxygen.

12. The Greenhouse Effect What is a greenhouse?
A greenhouse is a building made of glass where plants that need special care and extra warmth can be grown.
The sun shines through the glass of the greenhouse and warms the air inside it.
We cannot see the gases in the atmosphere, but they include oxygen, carbon dioxide, nitrogen and hydrogen.
The atmosphere is like a giant greenhouse. The Sun shines in, and the blanket of gases traps the heat like a roof, keeping it close to the planet.
This warmth and light are essential to all living things.

13. But factories, power stations and motor vehicles are making a lot of new gases.
Even trees, when they are burnt, give off gases.
These new gases are trapping more and more of the Sun’s heat.
This is called ‘the greenhouse effect’.
Because of the thicker blanket of gases, the Earth is warming up.
This is called global warming.
If it continues, it could begin to melt the Arctic and Antarctic ice caps.
The increase in the sea level would submerge nearly all of The Bahamas!

14. The ozone layer is in part of the atmosphere called the stratosphere, high above the surface of the Earth, and it protects the Earth from the Sun’s radiation.
Ozone is a form of oxygen which takes in much of the harmful ultraviolet radiation from the Sun.
In recent years scientists have noticed that the ozone layer is getting thinner in some places, for example over the continent of Antarctica.
This thinning is believed to be caused by chemicals called chlorofluorocarbons (CDFs), which are used in many manufactured goods like aerosol spray cans, air conditioners, refrigerators and polystyrene.
Scientists describe the thin patches in the ozone layer as ‘holes’.

15. The ozone layer screens the earth from most of the harmful ultraviolet rays radiated by the sun Ultraviolet rays can cause skin cancer.
Chlorofluorocarbons or CFCs are thinning the ozone layer. CFCs are used in aerosols, fridges, computers, plastic, foam and insulation materials.
Holes are developing allowing ultra violet rays to reach the Earth in greater amounts.

16. What can we do to help?
If you eat at a fast-food restaurant and are offered polystyrene cups and plates, ask for paper ones.
If they are not available, explain that while you like the restaurant’s food, polystyrene harms the atmosphere.
It is only by explaining facts that things will change.
It is clear that the atmosphere plays a very important past in our lives.
Without it humans could not survive on planet Earth.
It is important that we all try to keep the air, land and sea clean.
This is especially important In The Bahamas, because tourists come here to enjoy clear blue waters, clean beaches and fresh air.
Our natural resources must not be polluted.