“Our comforting sense of the permanence of our natural world, our confidence that it will change gradually and imperceptibly if at all, is the result of a subtly warped perspective. Changes that can affect us can happen in our lifetime in our world—not just changes like wars but bigger and more sweeping events. I believe that without recognizing it we have already stepped over the threshold of such a change; that we are at the end of nature. By the end of nature I do not mean the end of the world. The rain will still fall and the sunshine, though differently than before. When I say ‘nature,’ I mean a certain set of human ideas about the world and our place in it.”