Climate change and the developments it spurs carry the narrative of the Quaternary, the most recent 2.6 million years of Earth's history. Glaciers advance from the Poles and then retreat, carving and molding the land with each pulse. Sea levels fall and rise with each period of freezing and thawing. Some mammals get massive, grow furry coats, and then disappear. Humans evolve to their modern form, traipse around the globe, and make a mark on just about every Earth system, including the climate.

At the start of the Quaternary, the continents were just about where they are today, slowing inching here and there as the forces of plate tectonics push and tug them about. But throughout the