Polyglacial

The polyglacial concept (that is, the existence of many glacial periods and climate cyclicity) became accepted.

Our knowledge of Pleistocene glaciation has clearly shown that an ice age is not monoglacial, but polyglacial; i.e., during a single ice age several colder glacial [times] episodes alternate with warmer interglacial [times] episodes.

In the period leading up to World War One, there was much debate about whether the ice age involved a single phase of ice sheet growth and freezing climate (the monoglacial theory) or several phases of ice sheet build up and decay separated by warm interglacials (the polyglacial theory).