What would happen if nothing decomposed?

Answer 1

A corpse has been subjected to environmental conditions such that decomposition is significantly slowed down. There are a number of ways of retarding decomposition, but the mechanism commonly stated is that of saponification. Another environmental condition that can be the cause of retarding decomposition is a burial ground that is cool and dry. The retardation of decomposition also occurs if the ground is composed of soil that is high in certain compounds that bring the bodies' moisture to the surface of the skin. It is also suggested that bodies with low amounts of muscle and body fat tend to resist decomposition better. So if something does not decompose, it simply remains, while becoming more dried out in the case of a mummy, or sitting completely unaffected, but the cells are dead in the case of a frozen corpse.

Answer 2

Earth would become cluttered with dead plant and animal (and human) matter. We would have to get rid of waste by burning or something like that.