Cape Canaveral, June 1994: Six hundred scientists and engineers are touring the John F. Kennedy Space Center in a caravan of blue-and-white air-conditioned buses. They’ve gathered from thirty-four countries for the World Hydrogen Energy Conference, united in a dream to switch the planet from an economy fueled with dirty coal and petroleum to one run on clean hydrogen. They’ve come bearing designs for cars, appliances, aircraft, heating, cooling, and entire industries—all pollution-free.
For them, this is an inspirational pilgrimage. The white spherical tank on the pad, where the shuttle Columbia will presently lift spaceward, is filled with pure hydrogen. Since even before the moon shots, the power for NASA astronauts in space has come from hydrogen fuel cells, refillable devices that, like batteries, chemically convert fuel directly to electricity. Although the hydrogen that NASA uses was derived from natural gas in a process that also produces carbon dioxide, the conference participants are hopeful that the efficiency of solar technology will soon improve so much that water molecules, not hydrocarbons, will be the feedstock.
Nearly two decades later, they and a new generation of researchers, such as Arava Institute’s Tareq Abu Hamed, would still be hoping for an economical way of producing clean hydrogen energy. It’s frustrating, because there’s more hydrogen in the universe than all the other elements combined. Whether burned by internal combustion or injected into a fuel cell, its exhaust is simply water vapor. Theoretically, that exhaust could be captured, condensed, and tapped again for hydrogen, ad infinitum. A perfect, closed system—except for one annoying detail: In this universe, usable amounts of pure hydrogen gas occur naturally only in places like the Sun. On Earth, all hydrogen is tightly bound with other elements, such as oxygen, carbon, nitrogen, and sulfur. Breaking the bonds to free it—pulling the H out of H2O—requires more energy than hydrogen produces. The number of solar panels needed to milk enough hydrogen from water to run our civilization isn’t remotely practical. After years of trying, the most efficient way to extract hydrogen is still using superheated steam to strip it from natural gas, a process that also releases that pesky pollutant CO2.
That’s especially unfortunate, since during a lunch address at the 1994 hydrogen conference, NASA director Daniel Goldin imparted some disturbing news. Over the previous decade, he said, satellite data revealed that the world’s sea levels had risen nearly an inch. Goldin didn’t have to connect the dots for this particular audience: They knew the connection between the rise in seas, global temperatures, and the carbon dioxide expelled using man-made energy. Worldwide, four-fifths of our energy comes from ancient organic waste that nature didn’t need to run the planet, so it was buried safely away. Over eons, the buried organic matter compressed into highly concentrated coal and petroleum. Then, in less than three centuries, humans dug up hundreds of millions of years’ worth of the stuff and burned it. Its exhaust loaded the atmosphere with more carbon dioxide than the Earth has seen in at least 3 million years—a time when the world was rather balmy, and its oceans one hundred feet higher.
That was one of two reasons the hydrogen researchers were intent on an alternative to fossil fuel. The other was addressed that afternoon, by a physicist named Albert Bartlett. A University of Colorado emeritus professor, Bartlett professed to know little about hydrogen but something about basic arithmetic. He was particularly fascinated by what happens when things start to double.
“Imagine,” he said, “a species of bacteria that reproduces by dividing in two. Those two become four, the four become eight, and so forth. Let’s say we place one bacterium in a bottle at 11:00 a.m., and at noon we observe the bottle to be full. At what point was it half full?”
The answer, it turned out, is 11:59 a.m.
As awareness penetrated his audience, Bartlett nodded in return, his bald pate encircled by a few remaining gray tufts. “Now,” he continued, “if you were a bacterium in that bottle, at what point would you realize you were running out of space? At 11:55 a.m., when the bottle is only 1/32 full, and 97 percent is open space, yearning for development?”
Everyone giggled. “Now suppose that with a minute to spare, the bacteria discover three new bottles to inhabit. They sigh with relief: They have three times more bottles than had ever been known, quadrupling their space resource. Surely this makes them self-sufficient in space. Right?”
Except, of course, it doesn’t. Bartlett’s point was that in exactly two more minutes, all four bottles will be full.
Exponential doubling, he noted, doesn’t only gobble space. In 1977, U.S. President Jimmy Carter observed in a speech to the nation that, “During the 1950s, people used twice as much oil as during the 1940s. During the 1960s, we used twice as much as during the 1950s. And in each of those decades, more oil was consumed than in all of mankind’s previous history.” But as the century drew to a close, that rate inevitably had slowed.
“We’ve picked the low-hanging fruit,” said Bartlett. “Finding more gets progressively harder.”
Albert Bartlett didn’t know back then about twenty-first-century technologies for fracturing bedrock to release trapped natural gas, or squeezing the petroleum out of tar sands—or rather, he did, but at the time, when the price of oil was around sixteen dollars per barrel, their cost seemed prohibitively high, as in higher-hanging fruit. But even so, they were just the equivalent of finding a couple of new bottles: As demand keeps increasing exponentially with countries like China and India zooming past the United States, they at best give us a few more decades—and a lot more CO2.
Albert Bartlett, now in his late eighties, has told his bacteria-bottle story more than fifteen hundred times, to students, scientists, policy makers, and any group who will listen. “They still don’t seem to get it,” he laments, deploring what seems to have devolved into a race to see how much damage fossil fuels will wreak before they’re exhausted, as humans scrape ever deeper for the dirtiest ones.
He’s amazed that people find the concept of exponential doubling so slippery, even when he spices it up with more examples. In one, a Chinese emperor is enamored with a new game that one of his subjects has invented, called chess. He summons the inventor. “Choose your reward,” he commands. “Whatever you wish.”
“All I want is rice to feed my family,” he said.
“Done,” the emperor replied. “How much do you need?”
“Just a bit. In fact, Your Highness can measure it out on the chessboard. Put one rice grain on the first square. Put two on the next, and double the amount on each square thereafter. That will be sufficient.”
The emperor neglected to consider that anyone who could dream up chess must be a shrewd mathematician. At the end of the first row on the chessboard, the eighth square, the inventor had 128 grains of rice—barely a mouthful. But by the sixteenth, he was up to 32,768. After three rows, the tally was 8,388,608 rice grains, enough to empty the palace’s storerooms. By half the chessboard, he would be owed all the rice in China—and by the final square, 18 quintillion grains of rice: more than the entire planet had ever produced. Things never got that far, of course; long before, the emperor had him beheaded.
There are others, all forehead slappers: If you fold a sheet of paper in half, and could keep folding (seven folds is the usual physical limit), after forty-two times its thickness would reach the moon. But the entertainment value of exponential doubling begins to wane when it dawns on you that you’ve been one of the doublers. Albert Bartlett, who lives in Boulder, Colorado, began giving his talk in the 1960s when he saw a chamber of commerce brochure that boasted, “Doubling its population in ten years, Boulder is indeed a stable and prosperous community.”
Quick math showed Bartlett that if the doubling continued at that rate, by 2000 Boulder would be bigger than New York City. Some stability. Fortunately, the doubling slowed, as Boulder residents resisted developing all the empty bottles of open space that surrounded their city, lest the scenic reason for living there in the first place vanish—along with the city’s water supply.
In recent years, Bartlett has raised some controversy by proposing an end to immigration before the United States is engulfed with humanity. But even critics who challenge the ethical, practical, social, and environmental complexity of such a measure don’t argue with his math—especially when the scale gets so big that we lose sight of what’s happening to us. The planetary scale, for instance. In 1900, there were 1.6 billion people on Earth. Then, during the twentieth century, the world’s population doubled, and then doubled again. How much space did that leave in our bottle? How can we tell if, in fact, we’ve already filled it up?
The shuttles have stopped flying from Cape Canaveral. Something else has stopped in Florida, too, at least for now: the biggest single-dwelling housing boom in history. In 1999, the Tampa Tribune reported, land-use plans for the state’s 470 cities and counties would allow for 101 million residents, amounting to “stuffing the populations of California, Texas, New York and Pennsylvania into Florida’s borders.” That figure may have accurately reflected Florida planners’ chronic disregard for orchards, farms, woodlands, wildlife, lakes, rivers, and aquifers.
Ten years later, the ghost suburbs infringing one of Earth’s rarest ecosystems, the Everglades, attested that they disregarded more than that. A wasteland of empty Spanish-tiled condos, foreclosed shopping centers, and unfinished hospitals was succumbing to advancing mold atop what, a decade earlier, were marshlands filled with wood storks and endangered Cape Sable sparrows, edged by tomato fields.
This is one of several ground zeros in America’s Sun Belt of the 2008 subprime mortgage bust. Having run out of qualified home buyers as U.S. middle-class jobs were outsourced, banks invented mortgages based on a fantasy that someone who couldn’t afford monthly payments on 6 percent loans would magically be able to pay ballooned rates seven or ten years later. Concealing thousands of these dubious loans in packages impressively named derivatives, they then sold them to duped investors around the world. (For good measure, they purchased short positions on those packages that allowed them a tidy profit when they proved worthless.)
Presumably, the world now knows better—except, despite the economic carnage that left Florida with three hundred thousand vacant housing units, its local governments have since approved zoning for five hundred fifty thousand more. Such an apparent disconnect from reality reveals what psychologists might call a dysfunctional codependence between our population and our economy. If we measure economic health, as we commonly do, by the number of monthly housing starts, somebody has to live in those houses we then build, and furnish and decorate them, and buy whatever it takes to run and maintain them. That’s a lot of products, each representing jobs for whoever made and sold them. The more jobs, the more workers—wherever they live—needed to fill them. The more products, the more customers needed to buy them. That sounds nicely circular, and it might be—except for the more part.
At some point, something finally runs out. In the housing market collapse, the shortage was of people with enough money to pay their mortgages, leading to millions of foreclosures. But in the United States as in the world, people’s numbers keep growing nonetheless, and as they do, so must the planet’s economy to feed, clothe, shelter them—and beyond those basics, serve and entertain them in as many ways as they need or desire, and in as many ways as marketers can persuade them that there’s something new and exciting that they also need. So instead of a circle, it’s a spiral. Numbers spiral upward, cities spiral outward, housing adds up, and then suddenly there’s sprawl. Which, except for developers, is too much of a good thing.
In 1950, two-thirds of humans still lived rurally. Today, more than half live in cities. Urban dwellers, needing fewer farm hands, tend to have fewer children. In fact, humanity’s doubling rate has finally slowed. But slowing doesn’t mean not growing. To say that urbanization has solved overpopulation overlooks the fact that, in much of the world, the barn door was closed only after the horses had already bolted.
Even if today’s breeding generation is having fewer children per family, because their grandparents and parents had so many, every four-and-a-half days there are a million more people on the planet. Even to a schoolchild, that does not sound very sustainable.
There are now nearly five hundred cities with a million or more people. Twenty-seven cities have more than 10 million, and twelve of those have more than 20 million. (Greater Tokyo, the biggest urban area, has 35 million.) By the middle of this century, at our present decelerating pace, we’ll still add nearly half again as many people as we already have, increasing to between 9 and 10 billion,1 maybe more, all eliminating wastes and emitting carbon dioxide, all requiring food, fuel, living space, multiple services—and for those who’ve recently moved to town from the hinterlands, considerably more electricity to charge their mobile phones and plug in their inevitable TVs.
All that CO2 adds up, and keeps adding: A 2008 study by Oregon State University scientists Paul Murtaugh and Michael Schlax estimated that, predicting eventual emissions by a mother’s descendants, under current conditions in the United States, “each child adds about 9441 metric tons of carbon dioxide to the carbon legacy of an average female, which is 5.7 times her lifetime emissions.” It doesn’t take the math skills of a physicist to calculate that something is askew when five-hundred-year floods or storms start hitting twice or more in the same decade. In recent years, on every inhabited continent and archipelago, students have watched their schools drown.
As we struggle already with sustaining 7 billion, awakening to surprises like dust storms from China big enough to span oceans, or the forests of western North America, Siberia, and Australia exploding in flames, the prospect of 10+ billion not only defies our imagination, but like subprime lending, it might also defy reality. In the entire history of biology, every species that outgrows its resource base suffers a population crash—a crash sometimes fatal to the entire species. The issue may be not just whether we need to stop growing, but whether, for our own survival, we must humanely bring our numbers down from where they are now to a figure we can, literally, all live with.
Whether we accept it or not, this will likely be the century that determines what the optimal human population is for our planet. It will come about in one of two ways:
Either we decide to manage our own numbers, to avoid a collision of every line on civilization’s graph—or nature will do it for us, in the form of famines, thirst, climate chaos, crashing ecosystems, opportunistic disease, and wars over dwindling resources that finally cut us down to size. Managing population, as China has attempted, conjures frightening images of coercive governments invading our bedrooms and even our nurseries. Yet a surprising assortment of cultures have found nonintrusive ways to encourage people that smaller families might be in their own self-interest, as well as their society’s.
And the best interest of their planet?
“The idea that growing human numbers will destroy the planet is nonsense. But over-consumption will,” read a 2010 Prospect Magazine article titled “The Overpopulation Myth.” Many would agree: Reduce the amount of stuff in our lives, and shrink our footprint so that we’re not stomping the hell out of everything else. And learn to share: If we equitably distributed all the food we grow, there’d be plenty for everybody.
These are worthy goals. But the notion that everybody’s consumptive urge could be stifled anytime soon is probably wishful hoping. If saving the planet depends on changing acquisitive human nature—meaning, among other things, bucking the vast budgets of commercial advertising—the Earth will likely be thoroughly sacked long before that’s ever accomplished.
As for equal distribution of food: Does that mean among all living species, or just our own? Ever since God informed Noah that in order to start the human race anew, he had to save not just his family but all the animals, it should be understood that we can’t have a world without them. But with food production for humans currently occupying some 40 percent of the Earth’s nonfrozen terrestrial surface, plus all our roads, cities, and towns, we’ve claimed nearly half the planet for just one species—us. How are all the others going to make a living?
If everyone were vegetarian, herbivores argue, we’d only need a quarter of that land, since all the rest presently goes either to grazing livestock or to growing feed for them. (And producing a kilogram of beef emits as much carbon dioxide as an average car driving 160 miles, and uses ten times the water as a kilo of wheat.) All very true—but again, not so easy, as it’s also true that world meat demand is still rising, not falling. Most people, when they finally can afford it, tend to crave it. Healthier or not, vegans may not prevail anytime soon.
Since population is mainly growing in the poorest countries, and since poor women have the babies, to expect the weakest to rescue the world from the damage the most powerful have done to it seems grossly unjust. “Blaming environmental degradation on overpopulation lets the real culprits off the hook,” reads “10 Reasons to Rethink ‘Overpopulation,’ ” a 2006 issues paper on PopDev, a website run by Hampshire College’s Population and Development Program director and women’s health activist Betsy Hartmann. “In terms of resource consumption alone,” it continues, “the richest fifth of the world’s people consume 66 times as much as the poorest fifth. The U.S. is the largest emitter of greenhouse gases responsible for global warming—and the least willing to do anything about it.”
Except for China’s carbon emissions having now surpassed the USA’s, and the odds favoring the wealthy now being even more lopsided, these arguments are still persuasive. However, fair or not, in today’s global ecosystem everyone’s presence matters. Our numbers have reached a point where we’ve essentially redefined the concept of original sin. From the instant we’re born, even the humblest among us compounds the world’s mounting problems by needing food, firewood, and a roof, for starters. Literally and figuratively, we’re all exhaling CO2 and pushing other species over the edge. And not only is the United States an egregious polluter, it’s also still growing, faster than any other developed nation. Any discussion of population reduction that doesn’t include the USA would be pointless, let alone racist.
Then, there’s the rosy opinion that necessity has always given birth to invention when we need it, and that our creative knack for technology will surely solve the future—Israel’s technological optimism. “We learn how to dig deeper, pump faster. And we invent new sources of energy,” wrote University of Maryland economist Julian Simon in his 1996 book, The Ultimate Resource 2. The ultimate resource he referred to was human ingenuity, and he advocated population growth, so we’d have more of it.
Yet technological leaps have yet to solve anything without causing other unforeseen problems. Plus, as the hydrogen community knows, they’re hard problems. That includes the other form of hydrogen-based energy, cold fusion—basically, a controlled H-bomb—whose projected arrival seems perpetually forty years away. So far, our best alternative energy sources are solar and wind. Although there are multiple ways to apply them far more widely than we do, we’ve barely begun, and the world’s biggest business, intent on squeezing the last drop of petroleum out of the Earth’s crust, isn’t helping matters much. Even if we vastly improved our energy efficiency, to ramp solar and wind up to meet the demands of all our transport and industries, and of our Chinas and Indias, would be far beyond their capacity to deliver at this point.
And even if we somehow conjured up a truly limitless, emissions-free energy source, it wouldn’t cure traffic, or sprawl, or noise pollution. Inevitably, it would only stimulate hunger for more resources. However, the one technology that in fact could make a dent in our collective impact is one we already have: the one that lets us curb the number of consumers.
Family planning—a less onerous term for birth control—can’t solve everything: we still should try to convert everyone possible, especially the coming generation, from energy-addicted carnivores into sharing, environmentally astute, low-carbon sustainers. It’s also not without its perils: like anything else humans do, it can be, and has been, misused for evil, such as eugenics. And if population reduction implies a shrinking economy, we’re already plenty scared of that one. Yet when numbers come down, as Japan, whose aging population is already on the verge of shrinking, is discovering, there may be new opportunities for prosperity that we missed in the mad rush to grow and grow more, until we smash into reality.
Among them is the chance to equalize things far better than we have. So let’s define optimum population as the number of humans who can enjoy a standard of living that the majority of us would find acceptable. A standard of living, say, roughly equivalent to a European level, pre-euro-crisis2 : far less energy-intensive than the United States or China, far more hospitable than much of Africa or Southeast Asia, and with the highest possible percentage of educated, enabled women—which may be the most effective contraceptive of all.
So how many is that? And how do we get there?
Since it took nearly two hundred thousand years since Homo sapiens first appeared for our population to reach 1 billion, around 1815, and now we suddenly have seven times that many—how the hell did that happen? How did we get here?