“I predict that our civilization will survive until at least 2100.”

In his 2003 book, "Our Final Hour," Martin Rees writes: "I think the odds are no better than fifty-fifty that our present civilisation on Earth will survive to the end of the present century."

Dr. Rees is an eminent cosmologist, president of the Royal Society, and the astronomer royal of Britain -- but also, I think, a short-sighted prophet. He correctly notes that humanity will face unprecedented risks this century, but we will also have unprecedented tools to deal with them.

I believe the best way to predict the future is to look at past trends -- the longest trends possible. And my reading of history is that humans have a longstanding habit of surviving. As the late Julian Simon pointed out in his refutations of doomsayers, there is a long-term trend of humans facing news problems and not just overcoming them but emerging better-off as a result. Our species now has more members living longer than ever before. It's always possible this trend will end abruptly, but I think the odds are against it.