Doomsayers come, and they go. In the 18th century, Thomas Malthus predicted that the human population would outpace its ability to feed itself. Paul Erlich picked up that theme in the 1960s, but since then the world population has doubled. So what has changed?
Our own success as a species has created new a terrifying risks that didn't exist a few decades ago. By our dominating presence on the planet, we are in danger of upsetting climate systems in ways we don't fully understand. As the world becomes more global, we are putting ourselves in more intimate contact with other species, creating opportunities for new emergent diseases. To fight these pathogens, we are racing to unlock mysteries of biology, which could be used for good or for ill. We have built an elaborate global economy on technology that was never intended to handle this kind of scale and complexity.
No single one of these issues is necessarily a world ender. It's not like we're going to catch a bad flu and go extinct as a species, or that the stock market will crash and the world will be plunged into a thousand years of darkness, or that the seas will rise and engulf us. But taken together, it seems as though the world is headed into a period of great vulnerability. Climate and disease and food and economics are not wholly separate things--they are intertwined. If we are pushing everything closer and closer to some tipping point, it stands to reason that we are taking a risk.
In the book The Fate of the Species [Bloombury, $25.99] I delve into what these risks are. Think of it as sitting around a campfire and listening to scientists talk about what could do wrong. Here, in that spirit, are a few ways our world might just come to an end: