The natural greenhouse effect Water vapour, carbon dioxide, nitrous oxide and methane are natural greenhouse gases in the atmosphere. These gases act like a greenhouse because they trap some of the heat that has been reflected by Earth. This is called the greenhouse effect. The natural greenhouse effect maintains temperatures in a range that supports life on Earth.
Fig. 1 The greenhouse effect. Activity
Model making Model the greenhouse effect
Apparatus Two thermometers or temperature probes One-hole stopper to fit conical flask or test tube
Conical flask or test tube Aluminium foil Retort stand
Lamp with 200W bulb Stopwatch
Graph paper or spreadsheet Conical flask Fig. 2 Modelling the greenhouse effect.
Method 1. Insert a thermometer into a rubber stopper. 2. Insert the stopper and thermometer into the conical flask or test tube. 3. Attach a thermometer to a retort stand. Make sure it is at the same height as the other thermometer.
4. Place a sheet of aluminium foil behind the apparatus. This reflects the heat and light.
5. Record the temperature inside and outside the conical flask. 6. Position the lamp 10 cm from the apparatus. Turn on the lamp. 7. Create a data table to record the temperatures inside and outside the conical flask every 5 minutes for 30 minutes.
