Countdown: Our Last, Best Hope for a Future on Earth?By Alan WeismanLittle, Brown, 2013 Alan Weisman’s 2007 bestseller The World Without Us had a fantastically interesting story to tell: what would happen to the farmlands, cities, high-rise buildings, nuclear reactors, industrial dams, elevated highways, and sprawling mega-cities of the world if mankind were suddenly to disappear? The book’s most salient feature was its lack of grief; the overpowering assumption from first page to last was that mankind’s disappearance would be a great boon to the planet, a long-delayed chance for nature to take a deep breath and cleanse itself. Even the stereotypical post-apocalyptic detail of hardy cockroaches surviving everything was quickly dispensed with: turns out the little buggers need us a lot more than they’d have us believe.The World Without Us was, in short, a misanthrope’s hymnal.But once you’ve sold millions of copies of a book extolling the end of humanity, what do you do for an encore? Weisman has taken his time, but he’s finally come out with a follow-up to his earlier hit. It’s called Countdown, and it addresses a much more complicated hypothetical: is it possible to envision a future in which nature still gets to take a deep, cleansing breath even though humans are still around? Is it possible to write a hopeful book about the world with us?Weisman has travelled all over the planet and interviewed countless people – hydrologists, agronomists, economists, structural engineers, epidemiologists, and more – and the report he turns in is bursting at the seams with detail and color and conversation. But every interview, every expertly-rendered summary, every bit of exposition all comes back to the same vital detail: there are far, far too many humans on Earth.In his capstone chapter “The World With Fewer of Us,” Weisman faces the numbers squarely in a prolonged discussion about the goal of getting contraceptives to every woman on Earth who wants them:

Subtracting the avoided abortions and miscarriages, family planning in developing countries prevents 55 million unintended births. Since we currently add 80 million people annually – a million more of us every 4 ½ days – without contraception reaching those women, our ranks would expand by a million more hungry humans every 2 ½ days. That’s seven more Beijings a year, instead of the four we’re currently adding.

The image stops you in your tracks. Four Beijings a year. “Unsustainable” suddenly takes on a frighteningly concrete shape. Countdown is about many things and provides many illuminating digressions, but at its heart – as its title implies – it’s about the one problem that underlies everything else: the human population explosion. Weisman digs in and explains it with his customary clear readability:

Our current unprecedented numbers came about quite simply: After remaining nearly constant for roughly two hundred thousand years, during the last 0.1 percent of human history, each year fewer people have died than have been born. That happens only two ways: more births, or fewer deaths – and the two are inextricable. Over the past two centuries, we have become brilliant at beating back diseases or preemptively protecting ourselves from them. We repair damaged bodies. Through much of the world, we’ve doubled average human lifespans from under forty years to nearly eighty.Had we not done that and let nature take its usual course, it would periodically roar through our population with pandemics, just as it burns through forests to thin overgrowth, and there would be far fewer of us alive. Most of the 2.3 billion of us over forty would not be around. Almost half of all children would have died before age five, and at least one-fifth of all women would have died of pregnancy or childbirth complications before giving birth to all the ones they did.

Many writers have covered this ground before, and they’ve all arrived at the same conclusion Weisman does here: legally enforced population control is the only way to save the planet from the ravages of mankind – and the only way to save mankind from what happens when the overburdened planet begins to collapse. Weisman crunches numbers to show his readers the dramatic changes that would result from restricting every breeding human couple to one child each, or even two (“two will do” one expert smiles); even with decreased mortality and longer average lifespans, such a policy would very quickly bring the human population back to easily sustainable numbers.Such a medicine would be most bitter in the teeming underclasses of the developing world (Weisman implies what many studies have stated outright, that birth rates in the world’s more affluent nations continue to be in steady decline), and our author, having been to such places – including the wonderfully-described nether-regions of Mumbai – knows all about the social and political ramifications of what he’s advocating, but he doesn’t let himself draw back from it:

Human rights advocates often argue that the world’s poor are unfairly targeted for population control, because collectively they leave a much smaller footprint on the planet than the overprivileged few. That was surely true a half-century ago, when two-thirds of the world’s humans were peasants. Today most are urban – and most of them are urban poor. However ragged they may be, Dharavi’s rabble increasingly carry mobile phones; the electricity they use to charge them may be pirated, but generating it produces carbon nonetheless. The stupendous Mumbai traffic grew even more demented with the introduction of Tata Motors’ Nano, powered with a rickshaw engine and designed to sell for US $2,000 so that everyone might afford one. Most Dharavi dwellers probably can’t – but their children, already learning to colonize the twenty-first-century cyberscape, probably will. With the roads and rail tracks of Mumbai lined by more multistory housing for miles in all directions except seaward, their cumulative demand will broaden that footprint across what was once farmland and home to myriad tropical fauna.

When Weisman was a boy, he tells us, he used to visit the third floor of the old Minneapolis Public Library, where there was a display of stuffed passenger pigeons, whose numbers in America once reached incalculable dimensions. In 2013, the idea of the passenger pigeon evokes far darker thoughts from an older and more melancholy Weisman:

Humans wiped them out by 1914 – yet as I later read, even when there were a million left, they were already functionally extinct, because the pattern that doomed their critical habitat and food supply was already set. Was it possible, I now wondered, that my own species might also already be the living dead?

He ultimately hopes not, and readers of Countdown will feel that hope right along with him. Ill-judged or not.