The Quaternary is the geological period that spans the last 2.6 million years of Earth's history. The Quaternary includes the present ice age and is characterized by dramatic and frequent changes in global climate, from times of warmth (interglacials) to times of extensive cooling (glacials). Our species evolved during the Quaternary and studying the materials, processes, and history of this period is essential for understanding our origins.
The Quaternary is divided into two epochs: the Pleistocene and the Holocene. The Pleistocene started at the beginning of the Quaternary and ended ~11,700 years ago when the Holocene began. The Holocene has been a time of less abrupt climate concurrent with the development of modern civilization. Earth is now entering a time of unusually warm climate, and as a consequence we are likely to experience significant and potentially rapid environmental changes, which will pose major challenges for human habitability as it currently exists.
Study of the Quaternary provides an essential base line for defining ranges of natural variability and analogs for changes that may occur during times of rapid climate change.