Last Glacial Maximum

The Last Glacial Maximum (LGM) was the last period in the Earth's climate history during the last glacial period when ice sheets were at their greatest extension. Growth of the ice sheets reached their maximum positions 26,500 years ago. Deglaciation commenced in the Northern Hemisphere approximately 19,000 years ago, and in Antarctica approximately 14,500 years ago which is consistent with evidence that this was the primary source for an abrupt rise in the sea level 14,500 years ago. At this time, vast ice sheets covered much of North America, northern Europe and Asia. These ice sheets profoundly affected Earth's climate, causing drought, desertification and a dramatic drop in sea levels. It was followed by the Late Glacial Maximum.