Global warming is also called the greenhouse effect. The earth is surrounded by all kinds of gases. One of these is carbon dioxide (CO2). This gas ensures that the heat from the sun remains around the earth. It is a kind of natural protective layer. The more CO2 there is in the air, the more heat is retained in it.
Carbon dioxide is always surrounding the earth, and it protects the earth. But if this layer becomes too thick, problems arise. We call this the enhanced greenhouse effect. We as humans use a lot of energy, for example for cars, factories and heating. Fuel, such as oil, gas and coal, is needed to generate energy. Carbon dioxide is released when this fuel is burned. We are consequently enhancing the natural greenhouse effect by using large quantities of energy.