An interglacial is a geological interval of warmer global average temperature that separates glacial periods within an ice age. The current Holocene interglacial has persisted since the end of the Pleistocene, about 11,400 years ago. Interglacials during the Pleistocene During the 2.5 million year span of the Pleistocene, numerous glacials, or significant advances of continental ice sheets in North America and Europe have occurred at intervals of approximately 40,000 to 100,000 years. These lon… (More on Interglacial)