One Christmas Eve I was struck by the revelation that motherhood was not for me. I was living alone in a downtown warehouse, working as an artist and writer. More than once I'd joked with other freelancer friends that there is no such thing as a holiday when you work all the time, but Yuletide was upon me. 'Twas the season for family values, and as I contemplated my plans for Christmas Day, I spun a different fantasy in my mind, of what my life might have been like. Once or twice the opportunity to marry had come up, and I'd passed on it. If all had gone according to that plan, I would have probably been wrapping presents for my own children at that very moment. I could picture the house, the snow gently falling on the garden. I could picture the cat, the dog, and the mantlepiece.Once upon a time, I wanted a family. That was when I was young enough to believe I could be Superwoman, and do it all. But as I got older, my biological clock ceased to alarm me. It just wound down. That fateful Christmas I realized that I'd been overtaken by a desire to be something other than a mother. I didn't even mind the idea of being alone.I am certainly not alone, however, in my childless state.We've come a long way for no babies. Raised with the concept of choice, there have never been so many thirty-something childless women in the western world. Spinsters like me, or women with partners but no kids, are 20 percent of women in their childbearing years.Having or not having children is a deeply personal choice. But personal decisions beget political ones -- and the planet is already teeming with people. So why should we feel the need to reproduce at all?The population explosion was much on the mind of Dr. Jean Veevers when she was a Ph.D. student in the 1970s -- the era from which emerged the concept of Zero Population Growth, fueled by such books as Paul Erhlich's 1968 bestseller The Population Bomb.Thinking it might be illuminating to find out what makes people not have children, Veevers entered an area of research that had been virtually untapped. Her 1980 book, Childless by Choice, was a groundbreaking look at the worldview of those who choose childlessness. It's still one of the few book-length studies on the subject.Veevers' research focused on couples who had been together for at least five years -- the category of people who were most likely to have children and therefore more socially "deviant" in their choice not to. She was surprised to discover that concern about population was not foremost in the minds of her subjects, although many agreed it was important when asked directly. What emerged was just how many couples sit on the white picket fence. Many continued to say they might have children . . . eventually. There were so many other things they wanted to do first.Those who choose childlessness are still a minority -- although "twenty percent is a lot of people who don't have children", says Veevers, contemplating the recent statistics. She estimates half of those people are unable to have children because of physical limitations or lack of an amenable situation (e.g. insufficient funds) or an available partner -- or sperm donor.Veevers, herself single and childless (although she shares her home with three dogs and a parrot) notes that society has become more tolerant of "alternative" families and single mothers. But childless women encounter a chilly climate if they dare to challenge motherhood. Even in 1999 there is a powerful and unspoken ideology afoot: Thou shalt reproduce. Not to do so is to be somehow incomplete.According to Veevers, this "motherhood mystique" means that "there are two important norms: you should have children, and you should want them." As Veevers comments, "if you ask a pregnant woman why she is having a child, she won't be able to give you a list of answers." If, however, you start to ask yourself whether you should have a child, things are different."Just increasing the level of awareness to asking the question," says Veevers, "increases the likelihood of the answer being 'no', or 'maybe not'."Why do we repress the questions which might lead us to consider the implications of having children in the 21st century? The classic argument, posed to me by my own mother, is that to not breed is to be "selfish". But isn't it selfish to see the reproduction of one's own genes as life's raison d'etre? Is it really so selfish, at a moment in our collective evolution when we simply don't need more humans, to refuse to produce another one?The mystique we cling doesn't depend so much upon the innocence of children as the protection of our own innocence as adults. It's just natural to have children, the argument goes, and the planet's problems are not our fault. And women who don't want kids are, in sociological terms, deviant.I set out to do a survey of my own, asking a selection of deviant Victoria women a few prying questions about their reproductive aspirations.Many of the women I questioned remain anonymous, but some were willing to be quoted. Several fit into the "want to but can't" category, either for health reasons or the lack of the perfect man. Many reflected concerns about jobs and the economy. (In the new reality of freelance work, some are still getting a career started, let alone postponing motherhood for that career.) And yes, some of them were concerned about the planet.But in an interesting parallel to the research Veevers was doing in the 1970s, I found that when asked outright, "Do you want to have children?", with only one exception, all were resistant to just saying "No"."I find it easier to tell people that I am divorced and that my ex has custody of the children than to say that I am 34, single and childless," says Britta, a technical writer. With her long skirt and golden braid, she wouldn't look out of place as an Earth mother. But three years ago she left a disastrous relationship, hopped on her motorcycle and discovered a taste for the open road. Still, the pressure to conform has haunted her. "It's a social disease. How can you be a woman and not want to have children?" she asks.J. McLaughlin, a 33-year-old performance artist and sales clerk, has no reservations in saying an "emphatic no" to having a child. She adds: "The only people who believe you when you say that are other women who don't want kids." She would be part of the tiny four percent of women Veevers terms "early articulators", those who have never wanted children and always said so. Postponing a decision is what most people do, and there is always a reason why now is not the time.Laura Tinker, a teaching assistant, can relate. She and her partner recently bought a house complete with a wood stove, a dog and a cat. At 37, the baby question was part of her hurry for hearth and home. But now, with the mortgage and upkeep on their modest house, she's not sure if they can afford a family. She hasn't quite been sold on the mystique either, recounting tales of older mothers who have told her that they wouldn't do it again if they had the choice. "I almost wish I would discover I couldn't have a child," she says, "because then the decision would be over. I would just have to plan the rest of my life without kids."My friend Danielle and I have been talking about this topic for years. A documentary filmmaker, she has consciously planned her life around the freedom to work from home; combining work and family was always her plan. She's been married for eight years, but even at 37 her biological clock hasn't started ringing. She hesitates to say "no" to having kids, though, because she still feel an urge to be a parent."I have a very strong nurturing side. I just don't necessarily want to reproduce myself biologically. I wouldn't mind adopting," she says. Her biggest worry is that if she doesn't do it she will have missed a pivotal human experience, to have cut herself off from "all that love". On the other hand, she is afraid of being consumed by "baby, baby, baby and nothing but baby."This is probably the mother of all feminist fears: The loss of identity. "Your name disappears and you become 'mummy'," says Alice Bacon, 32, the administrator of a community theatre. But, together with her partner for 11 years and married for four, she too is not yet ready to say "never". Bacon also feels the ambivalence, the sense that she might end up missing something, and yet she's happy with her life as it is. For her, contemplating having a child or remaining childless produce the same worry: "I will be unhappy."The new mythology -- perpetuated by late-starter celebrity moms -- tells us we've still got time. (This is a common sentiment among my childless peers.) But it's running out, and we've learned that choice can mean anxiety. I'm turning 35 as I write this article, and now I've crossed another demographic threshold. Will women like me be pushing prams by the time the next decade ticks by? Statistics would indicate not: the likelihood of me having a baby in the next five years is only four percent. In spite of media hype about older mothers, the likelihood of a woman having her first child after the age of 40 has increased -- but only from .005 to .01 of a percent.Veevers points out that the reasons couples do not have children initially may not be the same reasons that cause them to remain without child later. Once they enjoy an adult-centered lifestyle, which means having the freedom to use their time as they please, it's hard to make the changes necessary to have a family. These changes may be greater in their perception than reality, but the effect is that they can begin to produce the desire to not have children.And once they cross over, they become more defiant. Some childless couples insist that they should be called "childfree", and have created a website (www.childfree.net) dedicated to their cause. In several North American cities a group called No Kidding! exists as a recreational outlet for singles and couples unencumbered by progeny.J. McLaughlin took her own childfree politics one graphic step further. At one of her recent performances, she described her travails attempting to "nurture a microchip" -- a Tamagotchi. After relating the hell that she'd been through to the gallery audience, she sledge-hammered the Tamagotchi to bits. The audience gasped, and booed. "All I felt was a sense of release," says McLaughlin now.The politics of personal choice aside, the other taboo question is: Since the global family is so big already, should you have children at all? One person who thinks that question should be paramount is Les U. Knight, the founder of the Voluntary Human Extinction Movement. Based in Portland, his community of the childfree extends "virtually" everywhere via a website (www.vhemt.org) and a newsletter called These Exit Times. Knight's message is simple: Don't breed."With 60 percent of conceptions in North America unintended, apparently we need a movement that simply gets people to think about their breeding," says Knight. "In light of the 40,000 children dying on an average day from a lack of care, and the obscene numbers of species going extinct as a result of our encroachment into their habitat, simple excuses such as 'I want to', aren't adequate."This debate is much older than we are. In 1798 Reverend Thomas Malthus warned that geometric increases in population would overwhelm our food supply, and the fear has been with us ever since. I even recall an episode of the 1970s sitcom All in the Family, in which Gloria and Meathead argued about population issues and whether or not to have a baby.But that anxiety seems to have passed. Dire predictions of a "great die-off" haven't occurred. Birth rates are going down -- and not only in North America, where they are 1.6 per woman (compared to 2.8 in the 1950s), but in the developing world as well. Many predict that by the middle of the next century, the world will have achieved zero population growth. So isn't a renewed fear of overpopulation just a bit of millennial hysteria?There is no consensus among demographers (or prophets), but even with slowing birth rates, the United Nations estimates that we'll pass the six-billion count this August. At around 2050, the world's population will top out at around 11 billion. The hard question, however, is not merely how many people there will be in 50 years, but how much of the planet's resources they'll need to survive.Perhaps the most comprehensive analysis of this human "carrying capacity" of the planet was carried out by Joel Cohen in his landmark 1995 book, How Many People Can the Earth Support? Cohen took stock of all population predictions through the ages, combined with an analysis of the methods used for calculating those predictions. While he admitted that the future is always uncertain, the Earth is finite, and that guarantees that there are ceilings on human numbers. Cohen determined that the median low for the planet's carrying capacity was 7.7 billion people, and the median high was 12 billion -- numbers we're close to reaching.That range depends on how we choose to live. Along with several other researchers, Dr. William Rees of the University of British Columbia has developed the model of the "ecological footprint" to measure the impact an individual or a population has on the planet. His equation calculates the amount of biosphere we need to sustain our existence -- and assimilate the wastes we produce. Our babies have big feet. Rees calculates it would take five planets to provide an American standard of living for every person already on Earth. Some people assume that since we don't have a naturally expanding population at home, we don't have to worry about population issues. But "the baby born in America today will have, in his lifetime, 20 to 30 times the impact of a baby born in Bombay," Rees argues. "We could dramatically reduce our total impact on the planet by reducing the population here."The counter-argument is that we don't have to worry, because ingenious humans always come up with new ways of expanding their resources. Malthus was wrong partly because irrigation and farm machinery enabled us to produce ever-greater quantities of food for our growing numbers; biotech advocates claim we'll feed even more with genetically-engineered crops. In the future cars will be powered by hydrogen, everything will be recycled, and electricity will come from the sun.These things could happen. But there isn't much evidence that we're ready to embrace such tools (aside from bioengineered food) in our own country -- or provide them at little or no cost to the rest of the world. And there's no reason to suggest that the way we distribute resources now will change when there are twice as many of us. Instead, there could just as easily be twice as much disparity between rich and poor. Unlimited growth, as the saying goes, increases the divide.What will happen depends upon how we act as individuals, as nations, and as a species. Ten years ago, the respected author Bill McKibben wrote The End of Nature, a book about the dangers of global warming. In his newest work, Maybe One, he argues that Americans should consider limiting their offspring because of the changes people are making to the Earth. McKibben argues that we are already on "Earth2", a different planet altogether, one whose biosphere is entirely dominated by human activity. Human beings have always altered their environments, but this time it is different. On Earth2, we're all in the same boat.So perhaps we need to challenge the motherhood mystique -- including the one surrounding our own planet. It's time for us to grow up and think of Mother Earth not as a tireless birth goddess, but as a wise parent who's done enough. She's already having hot flashes, and her menopausal revenge may be on the way. We should take care of her in her age -- along with the children who are already among us.Kristina Clarke is another one of my friends who confesses to being made to feel guilty for being childless."For some reason I feel like I am supposed to have children, but the more I think about it, I think my reasoning is based from the outside, from subtle societal expectations and traditions," she says. As an artist and teacher, she feels that working with children might be more important than simply having a child of her own.As it turned out, I didn't spend that Christmas alone -- I spent it with a family of friends. Around midnight a child even turned up, along with his parents. He'd been doing the grandparent rounds, but he still had enough energy to watch us open our gifts. He didn't seem upset that he was the only child in the room. Population theorists like McKibben say that we live in a "special time" in human history, and we should seriously consider having only one child. I suggest we also remove the stigma from having none. We are lucky enough to have choices -- it's only right that we make them carefully.