What is the green house effect?

Have you ever heard about the greenhouse effect? A greenhouse is a house that is specially made for plants to grow in. It is usually made up from glass or a see-through material so that the rays of the sun can get into the greenhouse for plants to photosynthesize (the process where plants make their own food by using sunlight, carbon dioxide and water).
If you have ever been in a greenhouse, you would know that it is usually nice and warm inside, even without any heaters! Do you know why it is so warm inside a greenhouse? The compost (decomposed or rotting plant material) in the soil may give of heat, but the main reason why a greenhouse is usually so warm inside, is because the rays of the sun enter the greenhouse. These rays get trapped in the greenhouse and the heat cannot escape. This also happens to our planet! Our atmosphere is just like the glass of the greenhouse; it lets the heat from the sun in and prevents it from escaping. This occurrence, where the heat of the sun gets trapped in our atmosphere is called the greenhouse effect.

How does the greenhouse effect work?

We now know that the heat from the sun gets trapped in the earth’s atmosphere, but how does this work and what causes the greenhouse effect? Let’s take a look at the greenhouse effect definition. The greenhouse effect can be defined as the occurrence whereby the earth’s atmosphere traps solar radiation (energy from a source that travels through space or a material). This is caused by the presence of gases in the atmosphere such as methane, carbon dioxide and water vapour. These gasses allow sunlight to come through the atmosphere towards the earth’s surface, but the heat that is radiated back from the surface is absorbed by these gasses.

Is the greenhouse effect bad?

You might have heard of the term “greenhouse effect” when someone was talking about global warming, climate change or the polar ice caps that are melting. These are all bad, but the greenhouse effect is actually good for us! If it weren’t for the greenhouse effect, our planet would be too cold for us to live on. Just like everything else in life, there has to be a balance. When there are too much greenhouse gasses in the atmosphere, more heat will get trapped in the atmosphere and the planet will get warmer and warmer.

Radiation and the greenhouse effect:

Have you wondered why the gasses in the atmosphere let heat waves from the sun enter but stops them from getting out again? The rays from the sun are called shortwave radiation. The light from the sun is a form of radiation because it carries energy and it moves through the atmosphere. Shortwave radiation contains more energy than longwave radiation. The sun has so much energy and heat that shortwave radiation leaves the sun and travels all the way to our planet. When these short waves enter our atmosphere, their energy is absorbed by the earth’s surface, clouds and gas particles in the atmosphere.

Not all the energy is absorbed and the extra energy is radiated in all directions. So, the waves have less energy when it is radiated back from earth. The shortwaves from the sun loses some of its energy in the form of heat, as soon as it makes contact with particles in the atmosphere or with the earth’s surface. The shortwaves turn into longwaves (infrared light) and particles in the air does not easily allow longwaves to pass and escape into space. The energy from these long waves is just re-absorbed and the atmosphere holds more and more energy as heat.

Important note – Greenhouse effect for kids:

Kids, do not sit in the car for too long on a warm day. The same thing that happens in the atmosphere, and that is called the greenhouse effect, happens in the car! The rays from the sun can enter the car with shortwave energy and the rays will lose energy by giving heat energy to the atmosphere in the car, the car interior and exterior. Longwaves will just bounce around in the car and give of more heat. It will not be too long before the car will become very warm inside. This can be very dangerous!

Now that you understand what the greenhouse effect is, you can tell everyone more about it! How do you think we can try to control the amount of carbon dioxide in the air?