"When we talk about saving the world, what world are we talking about? Not the globe itself, obviously. But also not the biological world—the world of life. The world of life, strangely enough, is not in danger (though thousands and perhaps even millions of species are). Even at our worst and most destructive, we would be unable to render this planet lifeless. At present it's estimated that as many as two hundred species a day are becoming extinct, thanks to us. If we continue to kill off our neighbors at this rate, there will inevitably come a day when one of those two hundred species is our own.
Saving the world also can't mean preserving the world as it is right now. That may sound like a nice idea, but it's also out of reach. Even if the entire human race vanished tomorrow, the world wouldn't stay the way it is today. We will never, under any circumstances, be able to stop change on this planet.
But if saving the world doesn't mean saving the world of life or preserving it unchanged, what are we talking about? Saving the world can only mean one thing: saving the world as a human habitat. Accomplishing this will mean (must mean) saving the world as a habitat for as many other species as possible. We can only save the world as a human habitat if we stop our catastrophic onslaught on the community of life, for we depend on that community for our very lives." - Daniel Quinn, Beyond Civilization