It used to be that we thought earth’s climate and its underlying geology changed slowly and steadily over time, like the tortoise who beat the hare. But now we know the opposite to be mostly true. The earth’s geophysical make-up doesn’t tend to incrementally evolve; it jerks back and forth between different equilibriums. Ice age, then greenhouse. Glaciers covering the island of Manhattan in a thousand-foot-thick sheet of ice, then a city of eight million people in that same spot.
Kanlaon 