Why does pop fizz when icecream is put in it?

Question

When you make a float, why does the pop fizz so much? It's like foam.

Answer 1

Soda fizzes when it comes in contact with ice cream.  According to the site, Ask a Scientist,

Ice cream is an emulsion of fat and sugar and other tasty things. When it melts these very tiny particles are released into the surrounding soft drink -- thus the nuclei on which CO2 bubbles begin.