Do you know what a greenhouse is? Well, a greenhouse, as we all know, is a building made of glass used for growing plants. The roof and walls of the greenhouse are made of glass. I will explain how the greenhouse effect is brought about. Sunlight can easily pass through the transparent roof and walls of the greenhouse. The sunlight then strikes the objects inside the greenhouse. Examples of these objects are plants, flower pots and tables. Now all these objects absorb energy in the form of heat. These objects become warmer and they give off heat. Most of the heat energy is trapped inside the greenhouse. Only a little of the heat energy escapes or passes through the glass. As a result, the temperature inside the greenhouse is raised. This is the reason why we will feel mush warmer inside a greenhouse than outside in the open air. Now, let us turn our attention to the earth. It is also acts like a greenhouse but on a very much larger scale. As the sun shines on the earth, solar energy from the sun passes through the atmosphere that surrounds our planet. The atmosphere is a mixture of gases around the earth. It is like the glass of a greenhouse. After passing through the atmosphere, solar energy strikes the surface of the earth and warms up the oceans, land and all the things on earth.
Then, the warmed surface of the earth gives off energy in the form of heat. The heat that is trapped in the atmosphere keeps the earth warm and makes life on the planet possible. The greenhouse effect will leads to the global warming. What is global warming? Global warming is an increase in the temperature throughout the world caused by the heat energy trapped around the earth. When global temperature increases, it will lead to many problems. So, we have to do something to prevent all these from happen. If pollution still continues to affect the environment, then our earth will be threatened. Therefore, we must do our best to prevent pollution and to preserve the environment.