Of all the urgent, practical, mind-bogglingly complex scientific questions pressing on humanity right now, the one Alan Weisman chooses to ask in this book is possibly the most important: What would Earth look like if every human vanished?
It's important because, as Weisman knows full well, it cannot really be answered. Even to think of the question – much less the answer – requires a magnificent suspension of the vanity that characterizes our species. In itself, that would make for a useful exercise. But Weisman, a U.S. author, journalist, radio producer and professor, has gone much further than just puncturing our species' sense of self-importance.
With his gentle, relentless, seditious question, Weisman forces us to acknowledge the effects our species has had on the planet, not least through our “Faustian affair with carbon fuels.” And then, without waiting for guilt, remorse, denial or defensiveness to kick in, he engages our imagination in what could have been or might even, if we are very lucky, still be. In other words, by refusing to ask how the heck humans are going to fix this mess we've made, he simply takes us out of the equation, and thus encourages our big brains to get to work on what he has not asked.
The result is catalytic. This book is the very DNA of hope, a loving nod to our vain, lethal, thoughtless species' immense capacity for good and creativity. It is a book designed to help us find the how of survival by shaking us out of our passive dance of death, our sinking into a plague-years mentality of despair over the state of the planet, or of its loathsome flip side, that earnest, faithless striving for tiny incremental change.
How does Weisman accomplish this remarkable feat?
In elegantly detached prose, all focused through the lens of the most up-to-date science, he asks subsidiary questions and then explores the answers with some of the world's top scientists, who bravely imagine the answers. What would happen without farms? If we vanish, would another primate – possibly the aggressive, human-like chimpanzee? – take over? What would happen to art? To music? To the resonance of human thought? Would the human-made wonders of our world survive? Would nuclear generators eventually stop generating? Would life come back to the oceans? Would birds notice if we left?
He takes us to a few of those remnants of the planet where the touch of humans is absent right now, whether because we somehow missed ravaging it or because we did that so long ago that nature has taken it back. So we go with him to the shreds of a primeval forest on the border of Poland and Belarus, to an alpine moor in the Kenyan heights – the birthplace of four African rivers – and breathe in a piece of the planet that has kept humans at bay.
We travel to a decrepit four-storey hotel in the war-torn Cypriot town of Varosha, abandoned abruptly in August, 1974, when the fighting began, and watch as a British electrical engineer cannibalizes other hotels to rebuild its air-conditioning system just two years later. Even then, trees are growing in cracked asphalt in this tomb of a town. The restoration falters and, 30 years on, all the human-built structures of Varosha are crumbling.
“Hotels – mute and windowless, some with balconies that have fallen, precipitating cascades of damage below – still line the riviera that once aspired to be Cannes or Acapulco. At this point, all parties agree, none is salvageable. Nothing is. … In the meantime, nature continues its reclamation project. Feral geraniums and philodendrons emerge from missing roofs and pour down exterior walls. Flame trees, chinaberries, and thickets of hibiscus, oleander, and passion lilac sprout from nooks where indoors and outdoors now blend. Houses disappear under magenta mounds of bougainvillea.”
More haunting is the description of just how quickly nature would dismantle Manhattan, returning it to the Earth and to the rivers that once underpinned the city. Without humans to heat and repair them, landmark buildings would begin to decay within a handful of years, exposed to the elements as the cycle of freezing and thawing split them open. The subways and the pavement would be destroyed within perhaps a decade. Even the toughest bridges would fail in two or three centuries, while skyscrapers, with their steel foundations, might not last that long.
Engineered plastic polymers, on the other hand, might well be on the planet for many thousands of years, unchanging, after humans depart. This is one of Weisman's most chilling stories. In the 50 years since the large-scale manufacture of plastics began, more than one billion tonsÖ have been produced, and there is still no plan for recycling. All but a tiny, incinerated portion of it still exists, dumped somewhere in the environment, most often the ocean, largely immune to decomposition by bacteria or sunlight.
As Weisman says: No plastic has yet died a natural death.
The sheer numbers of this stuff are shocking. Weisman reports that 5.5 quadrillion nurdles, the raw material of plastic production, are made each year, or about 250 billion pounds. They show up on beaches around the world, carried by the tides, eaten by sea creatures that later die of gut blockage.
An early study, in 1998, showed that there was six times as much plastic as plankton by weight on the surface of a 1,000-mile crossing of the North Pacific Gyre. A later study near the mouths of creeks in Los Angeles feeding into the Pacific Ocean showed 600 times as much plastic as plankton. That number keeps rising.
The human prognosis? Weisman wouldn't propound on that to save his life. This is the reader's journey, not the writer's pulpit. But in the coda, he leaves us with a tantalizing, draconian thought. If, as of today, every human female on Earth were limited to bearing a single child, the human population would drop dramatically. By 2100, the population of Homo sapiens would be at about 1.6 billion, the number we had in the 19th century before huge advances in energy, food production and medicine.
By comparison, if human reproductive rates continue on their current path, the world's population stands to reach nine billion by the middle of this century, a number that, short of some unimagined technological wizardry, would mean we have fatally fouled the nest.
And then? Weisman's parting thought is poignant. Just as light keeps moving, so, conceptually, does human thought, carried by electromagnetic waves. Maybe, he says, that will be the human legacy that nature can never erase. Once we are gone, maybe our thoughts or even our memories will keep bouncing around the universe, eventually finding their way back to the post-human Earth we betrayed and abandoned.
Alanna Mitchell is the author of Dancing at the Dead Sea: Tracking the World's Environmental Hotspots. She is working on a book about the health of the global ocean, to be published in 2008.
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