As a basic definition, it may be said that an Ice Age is simply a period of time during which thick ice sheets cover vast areas of land. These sheets have advanced and retreated, at times taking over the entire planet, and conversely disappearing nearly altogether. Glacial ice formed by this regularly occurring process does not sit in a state of inertia, but moves dynamically, reshaping the geological features of the continents. Again, the time frame for glacial movement is far longer than any involving human activity, so close attention must be paid in order to correctly measure and interpret it for the modern day.

From about 12,900 to 11,700 before present (BP), near Ice Age conditions returned to the Northern Hemisphere of the planet. It was a sudden shift from the warm temperatures that had prevailed for nearly 2,000 years. This period is referred to by archaeologists, geologists, and earth scientists as the Greenland Stadial, but it is more commonly known as the Younger Dryas.

The Younger Dryas marked the end of the last glacial period, the end of the Pleistocene Era, and the beginning of the Holocene Era, which is the current era. It was a period of great change, when climate change happened quite quickly, directly affecting the flora, fauna, and humans of the Northern Hemisphere in the process. The impact on the human populations was perhaps most important because, in some places, it virtually destroyed emerging cultures, while in other places, it might have propelled humans to develop new survival traits and technologies later used to move humanity into the Neolithic era. Although scholars now know quite a bit about the Younger Dryas, many elements of it are still debated. Other aspects serve as a predictor of what humans can expect in the future.

Extensive research about the origins and possibly the causes of the Younger Dryas will help modern experts understand more about climate change.