Science and Soda Pop


I can’t let the closing of the conference in Copenhagen pass without some comments on global warming.So let’s take a quick look at an important property of that “evil” substance, carbon dioxide: solubility.Time for an experiment!

Take a can or bottle of soda out of the refrigerator.Don’t drink it – just observe it.Pop the top and you get that characteristic sound of pressure within the container being released.As we pour it into a glass, immediately we see that bubbles are forming within the soda and floating to the surface, where they pop.These bubbles contain carbon dioxide.And what becomes of the bubbles?The carbon dioxide entered the atmosphere – probably to wreak havoc!

The solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid.By opening the container we decreased that pressure, and much of the gas could no longer remain in the liquid, so it left as bubbles.But some carbon dioxide remains there in your cold soda – dissolved instead of in bubbles.

As we continue to observe our soda, it begins warming to room temperature.We see additional bubbles forming, making their way to the surface, and leaving our soda.Our soda is going “flat.”No fizz.This additional loss of carbon dioxide points out a second factor in the solubility of gases: as temperature increases, solubility decreases.

What does this have to do with global warming?As the Earth warms slowly from its most recent Ice Age, less carbon dioxide can be dissolved within the vast reservoirs of our planet’s oceans, so it is slowly being released into the atmosphere – just like the bubbles in your soda.The obvious conclusion to an honest scientist is: global warming causes an increase in atmospheric carbon dioxide levels.

What we are hearing from the Copenhagen crowd is exactly the opposite: that carbon dioxide increases lead to global warming.

Which is true?Based only on our one-soda experiment, perhaps both.But certainly the former – just observe your can of soda.

Leave a Reply

Your email address will not be published. Required fields are marked *