Join renowned paleontologist Kirk Johnson on an epic adventure through time at the polar extremes of our planet. Following a trail of strange fossils found in all the wrong places—beech trees in Antarctica, hippo-like mammals in the Arctic—Johnson uncovers the bizarre history of the poles, from miles-high ice sheets to warm polar forests teeming with life. What caused such dramatic changes at the ends of the Earth? And what controls the dial on Earth’s thermostat? Today, the Arctic is warming faster than anywhere else in the world, and Antarctica has locked in its ice enough water to raise sea level by a terrifying 200 feet. The way that the poles respond to a warming climate is one of the greatest wildcards in predicting our climate future. Johnson uses Earth’s history, written in stone, as a cipher to decode what is going on at our polar extremes today, and what the future may hold.