ice age

A prolonged period of time, shorter than a geological era, in which the Earth's overall temperature notably decreases, resulting in an increase in the extent of ice sheets and glaciers, with both polar caps present and a marked expansion of them. Ice ages in turn encompass colder periods (glaciations), separated by warmer ones (interglacials). At present, we are living through one of them - the Holocene -, which began at the end of the last glaciation (Würm), about 12,000 years ago. We are, therefore, immersed in an ice age, something that is somewhat counterintuitive. It is very common to identify a glaciation or ice age with an era glacial (ice era).