Earth's sea levels during peak glaciation. Elliptical projection showing the Earth at a point of peak glaciation during an ice age, with ice caps and glaciers across North America, Europe and northern Asia. Peak glaciation occurs when glaciers and ice caps advance from the poles towards the equator, causing lowered sea levels (exposed land highlighted yellow). Earth has been in an ice age for the last 4 million years. The last maximum glaciation ended around 10,000 years ago. The current period is an interglacial, a warmer period where the ice caps retreat to the polar regions. For non-outline and non-highlighted versions, see C028/8014 and C028/8015.