PUBLISHED: 4:23 PM on Wednesday, August 1, 2007
Book explores world without humans
Take a quick peek outside your window and check out the scenery.

Are there trees and grass all around, or do you see lots of buildings? Does the land gently slope here, or are there craggy rocks over there?

Now, think a minute. Can you imagine what your corner of the world might have looked like to the first person who ever saw it? And would it go back to being that way if - poof! - you suddenly disappeared?

There are plenty of similar, thought-provoking questions in the new book "The World Without Us" by Alan Weisman.

Summertime usually means construction time in most areas of the country, but builders aren't the only busy people. Homeowners spend weekends maintaining their houses, road crews make repairs on streets, and grounds crews keep parks debris-free. But if we ceased to exist, and without our diligent care and upkeep, what would happen to our buildings, roads, or cities?

The answer is surprising.

Weisman says that the average barn would collapse within 10 years. Homes would be near-unrecognizable in 100 years, tops. Manhattan would be in ruins, re-claimed by wildlife, trees and plants within 300 years; a mere blip on Earth's timeline.

From New England forests criss-crossed with crumbling centuries-old stone fences to off-shore Pacific coral reefs choking on plastic garbage, we humans have clearly made our mark, but nature would quickly (relatively speaking) take back the planet if we weren't around to continually mess with it.

But before we go, Weisman wants us to know where we've been and what we did. If, as some scientists claim, humans crossed over the Bering Strait into Alaska and migrated south during the Ice Age, were they responsible for the mass extinction of large North American creatures like the Giant Sloth or the mammoth? When we're gone, will imported plants and birds - brought here with good intentions gone awry - take over completely? What would happen to nuclear weapons and stored poisons if we weren't around to keep them safely tucked away? If we disappeared, is there a chance that humankind could re-appear in another couple million years?

Got chores to finish, household repairs to make, maintenance to tend? Don't pick up this book, then, because you won't get any further than your easy chair if you do.

"The World Without Us" is one of the most engrossing, provocative, thought-starting, discussion-springing books I think I've ever read.

Author Alan Weisman - a first-rate storyteller - vividly describes scenarios as he hypothesizes; he prods a few scientists and experts for conjecture; and he goads readers into thinking differently about evolution, conservation, pollution, and the nuclear industry.

Although this book is obviously heavy on science, you'll hardly notice because Weisman yanks you in and entertains you while he expands your mind.

Although this isn't exactly a breezy summer read, I think "The World Without Us" is a definite don't-miss.

For a discussion-starter, for the person who wonders about life before civilization, or for anyone who likes to think deep, this book is out of this world.