Fifth Grade
Worksheets
What Causes Weather?
The sun warms the earth. The earth has a big invisible blanket wrapped around it. This blanket is made of air. The blanket is called the atmosphere. Weather happens in the lowest layer of the atmosphere. This layer of the atmosphere is where we live. The atmosphere lets the sun's heat and light pass through. It keeps most of the heat from escaping back into space.
The atmosphere traps the heat. It works just like the glass windows of a greenhouse. They trap the sun's heat inside. This is called the greenhouse effect. It's a good thing, too, or earth would be too cold for us to live on.
The planet Venus has too much of the greenhouse effect. Venus's atmosphere is mostly carbon dioxide. This is one of what scientists call "greenhouse gases." Carbon dioxide lets the sun's light and heat come into the atmosphere. Then greenhouse gases trap the heat instead of letting it pass back out. Because of this, Venus is the hottest planet in our solar system even though Mercury is closer to the sun. A day on Venus may reach 900 degrees! Too much of the greenhouse effect is what scientists worry is happening to earth now to cause global warming.
