The Greenhouse Effect
On a hot day a car is left outside in the sun with all the windows wound up. After an hour or so a person opens the door and gets into the car. The first thing the person notices is how hot the car is.
What has happened? The heat from the sun has entered the car through the glass and has been trapped inside the car, therefore the temperature rises. When the car door is opened, the trapped heat escapes and the temperature inside the car starts to reduce. + =
The atmosphere around the earth acts in a similar way by trapping some of the sun's heat. This is what keeps the temperature on earth warm enough to sustain life.
This trapped heat in the earth's atmosphere is called the Greenhouse Effect.
One main type of greenhouse gas is carbon dioxide which comes from burning fossil fuels. A fossil fuel can be, coal, gas, petrol, diesel or oil. Carbon dioxide is released into the atmosphere when there is a bushfire, when a heater is lit, when coal is burnt in a power station and when petrol is burnt in a car.
The more we burn fossil fuels, the more the atmosphere is polluted with greenhouse gases and the more likely the atmosphere will heat up! This is called Global Warming.
Most scientists are unsure what the effects of Global Warming will be or how quickly they will occur. Many think that more ice around the poles will melt and this will cause the sea levels to rise.
People from countries around the world are worried about the effects increased temperatures could have on our planet. They have started to develop a plan to reduce the rate greenhouse gases are released into the atmosphere. The agreement reached is called the Kyoto Protocol.