"The World Without Us"

In order to make sense of mankind's brief and potentially catastrophic sojourn on the Earth, Weisman turns to some foundational questions. Why did humans appear? Was it inevitable that they did? And if we vanished, could we reappear again? The crucial element here is ice: It was an ice age, Weisman argues, that led certain apes to leave the forest and venture onto the savannah, where eventually they became hominids. There was nothing inevitable about this, he implies, and nothing inevitable about it ever being repeated. If humans disappear, he writes, baboons stand as good a chance as any species of making the evolutionary leap -- and it'll take another ice age to drive them into the open.

Once humans did appear, they proceeded to change the world more than any other species -- in part by killing off a lot of other species. Weisman visits Arizona to talk to a paleoecologist named Paul Martin, who believes that when humans left Africa and Asia and came to North America, they exterminated three-quarters of the continent's late Pleistocene megafauna -- "a menagerie far richer than Africa's today." Huge animals like giant armadillos, giant short-faced bears twice as big as grizzlies, giant lions bigger and faster than African lions and, of course, woolly mammoths -- all were driven into extinction, Martin argues, because they did not suspect that the "runty biped" who confronted them was dangerous. Martin's theory, Weisman writes, remains "one of science's greatest flash points," the subject of endless debate.

Weisman concludes his discussion with a powerful scene in which Martin gives a speech in a museum filled with hundreds of stuffed heads shot by a world-famous big-game hunter. "My 50-year career has been absorbed by the extraordinary loss of huge animals whose heads don't appear on these walls," Martin says. "They were all exterminated, simply because it could be done." Martin's message, Weisman says, is that we are in danger of perpetrating an even worse mega-massacre -- one that might not even be driven by a killer instinct, but simply by acquisitive instincts "that also can't tell when to stop, until something we never intended to harm is fatally deprived of something it needs. We don't actually have to shoot songbirds to remove them from the sky. Take away enough of their home or sustenance, and they fall dead on their own."

In Africa, unlike the New World, the megafauna survived -- because they grew up with humans, and learned to fear them. If man disappeared from Africa, Weisman notes, the big mammals would flourish, with the elephant population, which now numbers half a million, returning to perhaps 10 million, where it stood before the ivory trade. But reality is less encouraging. Africa is the only place on Earth, except Antarctica, never to suffer a major wildlife extinction. As a result of overpopulation, poachers, cattle and changed habitats, however, the extraordinary African collection of megafauna is severely threatened. In what he calls an "insidious epitaph," Weisman notes that "Only one thing, too terrible to contemplate, might slow all this proliferating before all the animals go extinct": AIDS. Noting that the HIV virus probably spread to humans through bush meat, he asks rhetorically, "Could AIDS be the animals' final revenge?"

In some ways, one subject encapsulates this entire book: the fate of plastic. Ever since World War II, mankind has been creating staggering amounts of synthetic polymers -- one billion tons of the stuff. According to one expert, except for a small amount that has been incinerated, every bit of that plastic still exists, somewhere in the environment. Much of it is at sea: there is six times more plastic by weight on the sea's surface than there is plankton. All that plastic kills fish. Even if it ends up as powder, it will still be swallowed by jellyfish and other filter-feeders, with unknown consequences. None of it will biodegrade in any time frame that will matter; no organism has had time to learn to eat it yet.

It's a horrifying story, perhaps the most frightening one in Weisman's book. And yet the earth is strong enough to swallow even this vast, wretched McMeal. Weisman quotes a scientist who believes that in 100,000 years, some species of microbe will evolve that will eat plastic. And if not, there's always geologic time. "The upheavals and high pressure will change it into something else ... Change is the hallmark of nature. Nothing remains the same."

Rubber and petrochemicals are two of mankind's other contributions that will probably outlast Shakespeare, Mozart and the memory of humanity. Weisman explores Houston's vast "petro patch," the largest concentration of petrochemical refineries in the world. What would happen if humans stopped tending these plants? There might be a massive explosion. Or there might be endless fires in oil wells, like those started by Saddam Hussein in Iraq, that would bring on a chemical winter and release contaminated gases through the world. But in the end, this too would pass: Heavy metals would sink deep to the bottom of the ocean, buried by shells and compressed into limestone.

Weisman deals with just about every conceivable human artifact the earth would have to contend with after our departure, from farmed fields to PCBs to war zones to nuclear reactors. His discussions of the varied and unexpected ways our leavings would affect our planet are deeply researched, nuanced and fascinating. Not surprisingly, it's pretty clear that the Earth can take everything we throw at it. But there's a disquieting flip side: If we keep on going as we are now, the Earth may physically survive, but we won't. And even if we survive, the world as we know it will no longer exist. It is precisely because it approaches this issue obliquely, almost in passing, that "The World Without Us" is so memorable.

In his conclusion, Weisman changes his tone -- and reveals just how seriously he takes the problems he has been exploring. He calls for mankind to cut its birthrate dramatically by limiting every female to one child. By 2100, we would have reduced the human population to 1.6 billion, back where it was in the 19th century. The only alternative, he strongly implies, may be figuring out how to travel to other planets, either physically or by replicating ourselves remotely, cloning our bodies holographically and e-mailing our minds across the cosmos.

The consequences of mankind continuing on its more or less heedless path may indeed be this apocalyptic. But since Weisman has spent the entire book spinning a very different kind of tale, this dramatic choice comes as something of a shock. He hasn't laid out future scenarios of increasing destruction. And so this apparent either-or choice, posed at the very end of the book, is somewhat disconcerting.

But the dark note Weisman closes on inspires resolve rather than gloom. By appealing not just to our fear and guilt but to our love for our planetary home, "The World Without Us" makes saving the world as intimate an act as helping a child. It's a trumpet call that sounds from the other end of the universe, and from inside us all.

Story finder (3 ways to search Salon)

Search terms:

Salon the Web

Salon Directory (browse by topic)