Welsh 
Demonstrate the Solubility of Carbon Dioxide in Water
You will need:
- 2 identical bottles of a fizzy drink
- A fridge or freezer
What to do:
- Cool one bottle, then open both bottles. How does the amount of fizz vary between the bottles?
- The solubility of carbon dioxide in water decreases as the temperature increases - so more bubbles should form in the warmer bottle.
- This has an important consequence for the climate system - as the oceans warm, carbon dioxide, a greenhouse gas, is released into the atmosphere. This is one example of a positive feedback mechanism.
More Information
Find out more:
http://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores/
http://www.newton.dep.anl.gov/askasci/gen06/gen06306.htm