When Will the World End? New Theory Emerges

Jan. 22 -- The Earth has probably already peaked as a haven for plants and animals and begun its long descent into oblivion, according to scientists at the University of Washington who have plotted out the future of our planet.

These are not prophets of doom who have mounted the podium to warn us that we are killing ourselves through bad stewardship. They are scientists who say all good things must come to an end sometime, and at best we've got no more than half a billion years left.

After that, the planet will return to its ancient past, inhabited only by bacteria and single-celled organisms, just as it was in its earliest years. But in time even those will vanish as the Earth is reduced to a lifeless chunk of rock, or swallowed entirely by an expanding Sun.

And if you believe astrophysicist Donald Brownlee and paleontologist Peter Ward, there's not a whole lot we can do about it. They have laid out the grim facts in a new book, The Life and Death of Planet Earth, published by Times Books.

Time Is Ticking

Here are the essential nuggets in their findings:

Like any star, the Sun won't last forever.

There's a short window of about 1 billion years when it's possible for plants and animals to survive on Earth, and that's probably true of any habitable planet. We're already about half way through it.

Planets like this may be quite rare in the universe, so we better take care of what we've got. (With such dire predictions, you've got to allow these guys a little time on the soapbox.)

To simplify a very complicated story about the "devolving" of planet Earth, Brownlee and Ward have reduced its 12-billion-year lifespan to 12 hours, with the end coming at high noon.

It's only 4:30 a.m. in Earth's "day in the sun," as they put it, but by 5 a.m. the 1 billion-year reign of plants and animals will come to an end. By 8 a.m. the oceans will vaporize.

By noon it will all be over, about 7.5 billion years down the road.

It's not a pretty story, the two admit, but "Mother Nature wasn't designed to make us happy," according to Brownlee.