The Quaternary begins
The ice age we are still living in starts, and from here the climate never stops swinging.
- When
- Known to
- ± 20 thousand years
- Era
- Early Pleistocene, Quaternary
The base of the Quaternary is placed at 2.58 million years ago, at the point where large Northern Hemisphere ice sheets become a permanent feature of the system. What follows is not one glaciation but dozens: ice advances and retreats over and over, sea level swings by tens of metres each time, and no climate state lasts more than a few tens of thousands of years. Every subsequent event in this record — every hominin species, every migration, every extinction — happens against that oscillation.