This demonstration can be used to show how carbon dioxide in the atmosphere can attribute to global warming. It provides a very visual and simple explanation as to why CO2 is known as a 'greenhouse gas'
Equipment required (per set)
- two large (two litre) empty, clear drinks bottles that are identical
- two temperature probes (attached to dataloggers)
- two clamps, bosses and stands
- two heat lamps (identical)
- plasticine
- carbon dioxide gas
- timer
One of the bottles is filled with CO2 and the other with normal air. Taking care not to let any of the gas escape, use plasticine to secure a temperature sensor inside each bottle. Connect the sensor plug to a datalogger and set it to record temperature.
Clamp each bottle in an identical fashion and set up a heat lamp (or regular desk lamp) near each, making sure the distances between lamp and bottle are the same.
When the lamps are turned on the gas in each bottle warms. The bottle containing the CO2 should warm significantly more than the bottle containing air over time.
If conducted as a class practical, the dataloggers should be set to record temperature over time. After half an hour or so, students should be able to see the difference in temperatures between the two gases.