Greenhouses are made of glass and are designed to hold or keep heat inside. Our planet's atmosphere also helps to trap energy, acting like greenhouse. Energy from the sun can enter the Earth atmosphere, but not all of it can freely find its way out again.
What blocks the sun's energy from escaping from the earth?
Unlike the greenhouse, the Earth does not have a layer of glass over it, instead, molecules in our atmosphere called greenhouse gasses helps to absorb the heat. Greenhouse gasses include water vapour, ozone, methane, carbon dioxide and nitrous oxide. Some of these gasses might not be in large quantities but yet they can have a big impact.
Each greenhouse gas molecule is made of three(3) or more atoms that are bonded loosely together. These molecules have the ability to absorb heat energy and it is often absorbed by another greenhouse gas molecule.
The greenhouse effect is useful because traping some energy keeps the temperature on our planet mild and favorable for living things. Without its atmosphere and the greenhouse effect, the average temperature at the surface of the Earth would be zero degrees Fahrenheit.
Furthermore, too many greenhouse gases can cause the temperature to increase out of control. Such is the case on Venus where the greenhouse gases are abundant and the average temperature at the surface is more than 856 degrees Fahrenheit ( 457 degrees Celsius)
You might have heard people talking about the greenhouse effect as though it is a bad thing.
It is not a bad thing, but people are concerned because Earth's greenhouse is warming up very rapidly. This is happening due to the fact that we are currently adding more greenhouse gases to our atmosphere, causing or leading to an increased greenhouse effect. Therefore the Greenhouse Effect is causing changes in our planet that can affect our lives.