According to some biologists, the Earth is suffering an "infestation". The afflicting organism, "Homo sapiens" has overrun the planet. The infection is recent, several thousand years old in its most virulent phase. During that brief period, however, the surface of the planet has been seriously transformed. Alan Weisman has confronted the impact of our infection of the biosphere with an entirely fresh approach. Relying little on speculation, excepting only what might make the human species disappear, he points up our environmental foot print describing how the planet would recover from what our presence has effected. A captivating read, this book is at once an indictment and a challenge to our intellect and our values.
The great metropolis of New York City is one focal point in this account. Once traversed by 40 meandering streams feeding the ocean and river, the island, but for its striking Central Park, is now "tamed". Massive buildings line its many kilometres of pavement, and the storm sewer systems have replaced Nature's waterways. Yet, those rivulets persist, demanding flow rights. The loss of humanity would shut down the 753 pumps that keep the subway tunnels relatively dry. The streams, assisted by the bordering river and ocean would quickly inundate them. The bridges' streams of vehicles haven't stopped the return of wildlife to the city, and human abandonment would accelerate the process. Botany's realm, however, may never recover its original domain. Too many human-introduced species have an irresistible foothold. Those tall buildings bracketing the asphalt ribbons would also ultimately break down, providing havens for birds and small mammals before succumbing. The one species we've all been taught to be the ultimate survivor - the kitchen cockroach - would disappear with the first harsh winter.
Weisman doesn't limit his account for his native land's reading audience, however. The entire planet becomes his information hunting ground. An ancient patch of forest in Eastern Europe has been protected for centuries by hunting noblemen. While the deletion of humans would allow the forest to expand, it's likely the confined herd of European bison would enjoy the same recovery. In our original homeland, the natural predator-prey balance would be briefly offset by the ready meals our domesticated animals would provide. Herds of cattle, goats and sheep in Africa, untutored by natural selection to avoid lions and cheetahs, would fill feline bellies. Where the big cats would rule undeterred for a time, many microbes would be forced to make some spectacular adjustments. Oil dumps and nuclear stations, slowly breaking down would flood the landscape with hydrocarbons and radiation. Some microbes are already resistant to radioactive elements while some can "eat" oil. Others would have to expand their range of comestibles by adapting to them over millennia. Whether similar adjustments might be made for the mass of plastics we've dumped into the world remains an open question, Weisman says.
Although his original premise may be fantasy, the crux of his discussion is based on solid science. His interviews are with people who are in a position to gauge how we affect the world. Some of them are in place to prevent the recursion of nature into the habitat we've created for our species' benefit. One, archaeologist Arthur Demarest, is investigating a small segment of "the world without us", the site of the Maya realm. The 1600-year-long reign of those Central American people must have seemed "destined to thrive forever". The "spectacular, sudden collapse" took only a century. The return of the rainforest hides their existence from European invaders' eyes for another millennium.
Although Weisman's view of a dehumanised planet is compelling, almost desirable, he knows neither he nor his readership would be pleased by our extinction. We want to go on existing. Yet, he notes, "every four days, the world population rises by four million" - a clearly unsustainable rate of growth. Weisman has a scenario for survival, but its application would have to be nearly as instantaneous as his scenario of disappearance. His aim is curtailment of the human infestation - by the "draconian measure" of universal birth control. He argues that every human female must be limited to producing but one offspring. A challenging scenario, obviously, but one which he argues would reduce the planet's infesting species to a total of 1.6 billion by the end of this century. The number's validity may be disputed, but the goal is admirable. Could such a scenario possibly be envisioned, let alone implemented? It's that, he says, or a new wave of human colonisation - on other planets. [stephen a. haines - Ottawa, Canada]