Timeline of the Holocene

The time from roughly 15,000 to 5,000 BC was a time of transition, and swift and extensive environmental change, as the planet was moving from an Ice age, towards an interstadial (warm period). Sea levels rose dramatically (and are continuing to do so), land that was depressed by glaciers began lifting up again, forests and deserts expanded, and the climate gradually became more modern.

In the process of warming up, the planet saw several "cold snaps" and "warm snaps", such as the Older Dryas and the Holocene climatic optimum, as well as heavier precipitation. In addition, the Pleistocene megafauna became extinct due to environmental and evolutionary pressures from the changing climate. This marked the end of the Quaternary extinction event, which was continued into the modern era by humans.

The time around 11,700 years ago (9700 BC) is widely considered to be the end of the old age (Pleistocene, Paleolithic, Stone age, Wisconsin Ice Age), and the beginning of the modern world as we know it.