But our ice age was so recent that some places like Alaska and Canada are literally still bouncing back up from the removal of oceans of ice overhead—that is, the landmass is actually rising, year after year, like your seat cushion after you stand up. The height of this last ice age is popularly conceived to be a distant part of the planet’s past. But from a geological perspective, it was an eyeblink ago. If all of Earth’s history were represented by a 24-hour clock, it was half a second before midnight.*
