For nearly 10,000 years—since the dawn of civilization and the Holocene era—our world seemed unimaginably large. Vast frontiers of land and ocean offered infinite resources. Humans could pollute freely, and they could avoid any local repercussions simply by moving elsewhere. People built entire empires and economic systems on their ability to exploit what seemed to be inexhaustible riches, never realizing that the privilege would come to an end.