Where did it start? How did it grow complex? Why did it get big? Three moments in Earth’s early history when evolution suddenly, inexplicably turned up the dial.

© Photoillustration by Will Warasila for The New York Times

In these years, when climate change dominates much of the public conversation, it is worth looking back and remembering that the planet already experienced, just over two centuries ago, a sudden and devastating climatic upheaval, although of a very different origin than today. It happened in 1816, a year that the chroniclers of the time […]