The strategy of this book, then, is to awaken us from the dream that the world is about to end, because action on Earth (the real Earth) depends on it. The end of the world has already occurred. We can be uncannily precise about the date on which the world ended. Convenience is not readily associated with historiography, nor indeed with geological time. But in this case, it is uncannily clear. It was April 1784, when James Watt patented the steam engine, an act that commenced the depositing of carbon in Earth’s crust—namely, the inception of humanity as a geophysical force on a planetary scale.