THE GREENHOUSE EFFECT
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On lesson 4 we studied how light energy is transformed into thermal energy: when light energy hits an object, its molecules start to move faster, so the thermal energy of that object increases. As its temperature rises, the object starts to give off heat.
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This process also happens to the Earth. We call it the greenhouse effect. How does it works?
- The sunlight passes through the atmosphere and warms the Earth.
- Some of the heat is absorbed by the Earth, and some is radiated back towards the space.
- But not all of that radiated heat finally goes into the space: some is trapped by different greenhouse gases that are in the atmosphere, and it is redirect back to the Earth.
The greenhouse gases that are naturally in the atmosphere are water vapor, carbon dioxide, methane, nitrous oxide and ozone.
The greenhouse effect is a natural effect and it helps the Earth to be warm. Without it, life on Earth would not be possible.
The greenhouse effect is a natural effect and it helps the Earth to be warm. Without it, life on Earth would not be possible.
However, some human activities (such as burning fossil fuels, deforestation, farming,...), are increasing the level of some greenhouse gases, especially carbon dioxide. That means the more greenhouse gases in the atmosphere, the more heat is staying in the Earth. And this situation is making the temperature of the Earth to go up and up every year.
So, what would happen in the future if we continue producing more and more greenhouse gases? There would be:
Let's review this information with a flash animation. Click on the picture.
Time to watch some videos.
On the first video, you will learn why ozone is so important for life.
On the first video, you will learn why ozone is so important for life.
On the second video, you will watch the most dangerous effects global warming will cause on Earth.
On the third video, you will watch what would happen if the ice caps melted.
On the fourth video, you will learn how to prevent global warming.
Do you like playing games? So go to the games section to check what you have learned about this lesson.