The term "proliferation" is the act of greatly increasing something.
Proliferation is a quick duplication of parts or the expansion in the quantity of something. Nuclear proliferation is a quick increment of nuclear weapons.
The proliferation of any living thing will frequently make an overpopulation issue and cause an environmental imbalance. We quite often utilize this word to depict stuff we would prefer not to increment quickly. The excessive proliferation of transformed cells, for example, is the way cancer develops.