Hey lauren! Lol, interesting question!! Burping is a way for us to expel excess gas from our digestive system (mostly from the stomach and esophagus). Sometimes we swallow excess air when we are eating. We also burp more after drinking soda because of the carbonation – that carbonation is all just carbon dioxide gas. We have to get rid of it some how!! Burping is the way our body does it.
Its a little gross but…generally burps are caused by swallowing air while eating or drinking. This air then escapes through the mouth. Fizzy drinks can also release the gas that causes the bubbles once they are in the stomach – this gas also needs to be expelled (i.e. got rid of!!)